JP7281454B2 - Pipette calibration/volume offset mechanism - Google Patents

Description

[0001] Exemplary embodiments described herein are generally directed to calibration and volume (capacity or volume) offset (correction) adjustment mechanisms for adjustable volume pipettes.

[0002] As will be appreciated by those skilled in the art, a pipette is a device typically used with a pipette tip to transfer or dispense a measured volume of liquid from one location to another. be. Manually-operated air-displacement pipettes, such as those most relevant to this application, generally operate by creating a vacuum by retracting a piston located within the pipette body. Thus, when the open end of the associated pipette tip is immersed in liquid, the resulting vacuum draws air from the pipette tip, resulting in a certain amount of liquid being drawn into the tip, thereby Replaces exhausted air. Movement of the pipette piston is adjusted to draw a desired, measured volume of liquid into the tip during the aspiration phase of the pipetting operation.

[0003] Manual air displacement pipettes are available in a wide range of volumes, between about 0.2 μL and thousands of μL. Because a user may need to pipette many different liquid volumes, such pipettes are frequently used in a variety of volume ranges (eg, 0.5-10 μL, 10-115 μL). , 115-1,000 μL) and with volume adjustability within a selected volume range. Volume adjustability is generally accomplished, for example, by manually rotating a built-in volume setting shaft or manually rotating a pipette plunger button and associated plunger, thereby providing a variety of possible associated mechanisms. Vary the pipette volume setting via one of the mechanisms.

[0004] A general drawback of known adjustable-volume pipettes is that it takes time and effort to make volume adjustments, especially when the difference between the current volume setting and the desired volume setting is large. is what you need. For example, in the case of known adjustable volume pipettes, only 5% to 10% of the total volume of the pipette can be changed by one complete revolution of the pipette volume adjustment device. Therefore, making large changes in volume can require a great deal of time-consuming effort on the part of the user.

[0005] Adjustable volume pipettes with fast volume adjustment are known. However, these known pipettes have various deficiencies, including, but not limited to, a complicated and/or imprecise volume adjustment mechanism, slow volume adjustment and fast volume adjustment. and/or the need to provide a volume adjustment input separate from the pipette plunger rod or plunger button.

[0006] As will also be appreciated by those skilled in the art, accurate pipetting requires calibration of the dispensed fluid volume. Therefore, pipettes are typically calibrated at the factory and possibly even during maintenance work.

[0007] In one known pipette embodiment, calibration is achieved by disconnecting the volume display from the associated volume screw, and volume offset is achieved by separately moving the bottom stop. In another known pipette embodiment, calibration is accomplished by unscrewing the volume display from an associated volume screw using a spline-type coupling located within the counter (counting) wheel of the volume display and then removing the volume screw. Accomplished by adjusting the position. In yet another known pipette embodiment, calibration and volume offsets are achieved by moving the upper stop of the pipette without changing the pipette volume display.

[0008] From the above description, it is apparent that adjustable volume pipettes and pipettes that allow calibration or volume offset by the user are known. However, given the identified drawbacks of known adjustable-volume pipettes in relation to the large number of pipetting operations and accompanying volume adjustments made by many pipette users in the normal course of the workday, The advantage of providing an improved embodiment that facilitates more efficient pipette volume adjustment will be readily apparent. Similarly, a simplified compact pipette calibration/volume offset mechanism that can be used with the improved pipette volume adjustment mechanism of new manual pipettes even though mechanisms and techniques for pipette calibration and volume offset are known. should be provided.

[0009] Exemplary embodiments described herein are directed to a quickset mechanism for easily and quickly adjusting the liquid volume of a manual (manual) adjustable volume pipette. and Other exemplary embodiments described herein are directed to a combined pipette calibration and volume offset mechanism that may be used in manual pipettes, including, but not limited to, volume Adjustable manual pipettes and the like. Yet another exemplary embodiment described herein comprises a volume adjustable manual pipette employing a quickset mechanism for rapid volume adjustment and a combined pipette calibration and volume offset mechanism such as Intended for use with quick-set pipettes.

[0010] An exemplary pipette quickset volume adjustment mechanism (quickset mechanism) allows a user to quickly and accurately adjust pipette volume. Generally speaking, volume adjustment is accomplished by adjusting the position of the pipette volume screw via rotation of the pipette plunger button (which rotates the plunger rod to which the plunger button is attached). A quickset mechanism has a dedicated planetary gearbox selectively rotatably coupled to the plunger rod adapted to change the rotational speed ratio between the plunger rod and the volume screw.

[0011] In one exemplary embodiment, the quickset mechanism may provide the user with three input modes: a direct drive mode, a speed multiplying mode, and a lock mode that prohibits volume adjustment. In direct drive mode, the volume screw of the pipette is directly driven by rotation of the plunger button (ie, 1:1 ratio). In the speed increasing mode, rotation of the plunger button drives the planetary gearbox, which in turn rotates the volume screw. A planetary gearbox can have a wide range of possible speed ratios (eg, 4:1). Thus, when the quickset mechanism is set to the increased speed mode, one rotation of the plunger button will result in multiple (eg, four) rotations of the volume screw. This allows the user to make large changes in volume quickly and accurately. After using speed increase mode, the quickset mechanism can be set to direct drive mode to make final minute volume adjustments. Lock mode can be used to prevent inadvertent volume changes or deviations after the desired pipette volume has been set.

[0012] An exemplary embodiment of an adjustable volume manual pipette with a quickset volume adjustment (quickset pipette) includes a body portion and a body portion attached to the body portion at its distal end. Similar to a conventional manual pipette in that it can have a distal mounting shaft mounted on the pipette, a piston assembly with a piston, a stroke spring, and a plunger button attached to a plunger rod coupled to the piston. do. A user can axially displace the piston via a plunger button and associated plunger rod to aspirate or dispense a liquid of interest. A quick-set pipette further has a quick-set mechanism, such as the exemplary quick-set mechanism described above. Thus, the exemplary quick-set pipette allows the user to easily and quickly make precise volume changes while aspirating and dispensing various volumes of liquid.

[0013] Exemplary quickset pipettes may further have a combined calibration and volume offset mechanism by which the pipette may be calibrated and/or a volume offset applied. Generally speaking, this exemplary calibration/offset mechanism comprises, among other components, a mode selection mechanism, a follower element, an offset counter, a user rotatable input mechanism, a (calibration) housing, a pipette a coupling device for coupling the offset counter to a threaded element that is axially displaceable to adjust the home position of the pipette, where the pipette increases the aspirable liquid volume or A calibration/offset mechanism is attached to the pipette to reduce it.

[0014] An exemplary calibration/offset mechanism may be mounted within an adjustable volume manual pipette, such as, but not limited to, an exemplary quickset pipette. In either case, the pipette can still have conventional manual pipette components such as those mentioned above. If the pipette is a quickset pipette, the calibration/offset mechanism is mounted within the pipette body along with the quickset mechanism.

[0015] A calibration adjustment is performed by first rotating the input mechanism, which is rotatable by the user of the calibration/offset mechanism, so that the offset counter displays a "zero" offset. The mode selection mechanism is then placed in calibration mode, thereby disconnecting the offset counter from the coupler. The pipette can then be calibrated by the user by turning an input mechanism that is rotatable, thereby adjusting the axial position (and volume) of the home position of the pipette by axially displacing the screw element. do. In this way, for example, the volume can be adjusted until the gravimetric reading of the aspirated liquid dispensed by the pipette matches the pipette set point displayed by the counter wheel of the volume display.

[0016] To perform a volume offset, the user first ensures that the mode selection mechanism is in offset mode, which is the default mode in this exemplary embodiment. This involves an offset counter which is normally set to zero. A desired volume offset can then be input by the user by turning a rotatable input mechanism, thereby axially displacing the screw element axially to the home position and volume of the pipette. adjusted again. In offset mode, the amount of offset that is input is tracked and indicated by an offset counter.

[0017] Other aspects and features of the general inventive concept will become apparent to those skilled in the art from a detailed reading of the following detailed description of the illustrative embodiments in conjunction with the accompanying figures.
[0018] In the drawings and the following description of the illustrative embodiments, like reference numerals indicate the same or equivalent features throughout the several views.

[0019] Fig. 4 is a cross-sectional view of an exemplary adjustable volume manual pipette incorporating an exemplary quickset volume adjustment mechanism and an exemplary calibration/offset mechanism; [0020] Fig. 4 is an enlarged perspective view of an exemplary quickset volume adjustment mechanism; [0021] Fig. 3 is a cross-sectional view of the exemplary quickset volume adjustment mechanism of Fig. 2; [0022] Fig. 3 is an enlarged exploded view of the exemplary quickset volume adjustment mechanism shown in Fig. 2; [0023] Fig. 4B is another enlarged exploded view of the planetary gearbox shown in Fig. 4A; [0024] FIG. 5 is a schematic enlarged view showing an exemplary quickset volume adjustment mechanism positioned in each of three different modes of operation; 4A-4D are schematic enlarged views showing an exemplary quickset volume adjustment mechanism positioned in each of three different modes of operation; 4A-4D are schematic enlarged views showing an exemplary quickset volume adjustment mechanism positioned in each of three different modes of operation; [0025] Fig. 2 is another cross-sectional view of the exemplary adjustable volume manual pipette of Fig. 1 showing the adjusted liquid volume after operation of the installed quickset volume adjustment mechanism; [0026] Fig. 4 is an exploded perspective view of an exemplary calibration/offset mechanism; FIG. 4 is an exploded perspective view of an exemplary calibration/offset mechanism; [0027] Figures 7A-7B are enlarged perspective views of the exemplary calibration/offset mechanism of Figures 7A-7B in various assembled states; 7B are enlarged perspective views of the exemplary calibration/offset mechanism of FIGS. 7A-7B in various assembled states; FIG. [0028] Fig. 7B is an enlarged cross-sectional view of the exemplary calibration/offset mechanism of Fig. 7B; [0029] FIG. 10A is an enlarged perspective view of an alternative exemplary quickset volume adjustment mechanism; FIG. 10B is an enlarged top view showing an alternative exemplary quickset volume adjustment mechanism. [0030] FIG. 11A is an enlarged side view of the exemplary quickset volume adjustment mechanism of FIGS. 10A-10B; FIG. 11B is an enlarged front view of the exemplary quickset volume adjustment mechanism of FIGS. 10A-10B. [0031] Fig. 1OB is a cross-sectional view of an exemplary quickset volume adjustment mechanism along line AA of Fig. 1OB;

[0032] "Limited" as used herein means that macro motion of a given component in a given direction is possible, but limited to only some forms intended to be

[0033] As used herein, "constrained" is intended to mean that macro motion of a given component in a given direction is not allowed.
[0034] As used herein, "macro-motion" is intended to mean motion beyond that permitted by a slip-fit type clearance. For example, a rotating shaft is considered to have no macro-motion in a direction perpendicular to the axis of rotation even if clearance is provided to allow free rotation.

[0035] One exemplary manual quick-set adjustable volume pipette (quick-set pipette) 5 is depicted in cross-section in FIG. A quick-set pipette 5 generally has a body 10 for being gripped by a user. The pipette body 10 has a tip mounting portion 15 at its distal end 10b. A tip mounting portion 15 is adapted to receive and hold a pipette tip (not shown). Because the plunger assembly of the quick-set pipette 5 is operated by a user with a piston 20 reciprocatingly positioned within the body portion 10 and a plunger rod 25 extending proximally upward from the piston. a plunger button 30 located outside the body portion 10 affixed to the proximal end of the plunger rod. A stroke spring 40 is present in body portion 10 to drive piston 25 proximally during the liquid aspiration phase of the pipetting operation. A blowout spring 45 of a blowout assembly 500 (see FIGS. 8A-8B) is also present within the body portion 10 and, as will be appreciated by those skilled in the art, after dispensing the aspirated liquid from the pipette. It functions to retract the piston 25 from any possible blowout operation. Additionally, a tip ejector 35 may be further provided for ejecting the pipette tip from the tip mounting shaft 15 if desired.

[0036] Because the quickset pipette 5 is an adjustable volume pipette, a volume adjustment assembly is further provided for effecting the desired volume changes. A volume adjustment assembly has, among other components, a plunger rod 25, a plunger button 30, and a substantially hollow volume screw 50 through which the plunger rod passes. In this exemplary embodiment, the bottom surface of volume screw 50 defines the upper stop position of the plunger assembly, such as by contacting flange 380 on plunger rod 25 .

[0037] A volume setting display assembly 400 with a volume setting display 55 visible through an opening 60 in the body 10 of the quickset pipette 5 may be further included to indicate the current pipette volume setting. As will be explained in more detail later, the volume adjustment assembly of quickset pipette 5 further includes a quickset volume adjustment mechanism (quickset mechanism) 65 that facilitates rapid adjustment of pipette volume when desired. have.

[0038] This exemplary quick-set pipette 5 further includes a calibration/offset mechanism 250, as will be described in more detail below. A calibration/offset mechanism 250 allows the pipette to be factory calibrated or recalibrated and/or to set a volume offset by a user, maintenance personnel, or the like.

[0039] Aside from the unique functionality provided to quickset pipette 5 by quickset mechanism 65 and calibration/offset mechanism 250, quickset pipettes generally also operate in a manner familiar to those skilled in the art. That is, during the liquid aspiration phase of pipetting operation, the user depresses the plunger button 30, thereby axially moving the piston 20 from the upper stop position to the lower stop position (home position) against the biasing force of the stroke spring 40. Let In this case, the open end of the pipette tip (not shown) is placed in the liquid of interest and the plunger button 30 is released, causing the stroke spring 40 to move the piston 20 while simultaneously aspirating a constant volume of the liquid of interest. can be returned to the upper stop position. To dispense an aspirated liquid, the user positions the pipette tip over the desired container and depresses plunger button 30 again, thereby moving piston 20 from the upper stop position to the home position. Once the aspirated liquid has been dispensed, the user further depresses plunger button 30, thereby causing additional axial movement of piston 20 and compressing blowout spring 45, thereby performing a further blowout operation. be able to. When the blowout operation is complete, the release of the plunger button 30 returns the piston 2 to the upper rest position again, this time by the combined biasing force of the blowout spring 45 and the stroke spring 40 .

[0040] As noted above, because of the significant amount of volume change between successive aspirate/dispense operations, the volume adjustment assembly includes the exemplary quickset mechanism 65 and the exemplary The quickset mechanism 65 of allows for selectively increasing the speed so that the pipette volume can be adjusted. More detailed views of an exemplary quickset mechanism 65 can be seen in FIGS. 2-4B. As best shown in FIGS. 3-4B, the exemplary quickset mechanism 65 includes a transmission input device 70 and one or more cam follower pins 75 located on a distal portion of the transmission input device. , a first (direct drive) barrel cam 80, a gearbox input 85, a second (velocity increasing) barrel cam 90, a planetary gearbox 95, a gearbox output shaft 100, and a direct drive lock plate 105; have The first barrel cam 80 and most of the remaining quickset mechanism components are retained within the frame 10 when the quickset mechanism 65 is in the assembled state as shown in FIG. A plunger rod 25 passes axially through the quickset mechanism 65 .

[0041] The transmission input 70 of the quickset mechanism 65 functions as a mode selector through which the user can adjust the pipette volume using fine (direct drive) or coarse (increase speed) modes. You can choose to adjust the In some embodiments, the transmission input device 70 can also be used to lock the quickset mechanism, thereby prohibiting volume adjustment by the user and preventing inadvertent changes or deviations in the selected pipette volume. do. A transmission input device 70 is located at the proximal end 10a of the pipette body 10 and typically has a lever 165 or lever 165 projecting through an opening in the pipette body for facilitating rotation of the transmission input device by a user. It will have another suitable actuator. In this exemplary quick-set pipette 5, the transmission input device 70 further has selectable detent mode positions corresponding to each of the direct drive, increased speed, and lock modes of the quick-set mechanism. The communication input device 70 further comprises one or more pointing elements 170 that can correspondingly point to mode numbers, symbols, or other graphical mode identifiers (or indicia) located on the pipette body 10. be able to. Indicator element 170 will indicate the volume adjustment mode selected by the user via rotation of transmission input device 70 .

[0042] The direct drive barrel cam 80 and the velocity increasing barrel cam 90 each have one or more arcuate or sloped cam slots 80a, 90a, whereas the frame 110 has one or more linear retention slots 110a. have When quick set mechanism 65 is assembled, the locations of cam slots 80a, 90a and retention slot 110a substantially correspond to each other. However, the cam slots 80 a , 90 a may have somewhat different shapes or orientations to cause the desired individual movement of the direct drive barrel cam 80 and the velocity increasing barrel cam 90 . Similarly, one or more cam follower pins 75 are mounted in one or more cam slots 80a, 90a and 1 in each of the assembled direct drive barrel cam 80, velocity increasing barrel cam 90 and frame 110. It extends through or into one or more retention slots 110a. Thus, the direct drive barrel cam 80 is rotationally constrained by the frame 110 and axially limited by movement of one or more cam follower pins 75 of the transmission input device 70 residing within the cam slots 80a of the direct drive barrel cam. be. During rotation of transmission lever 165, one or more cam follower pins 75 rotate within slots 110a in the frame, thereby positioning direct drive barrel cams 80 and velocity increasing barrel cams 90 therein. Corresponding interaction of cam slots 80a, 90a with one or more cam follower pins 75 causes upward or downward movement.

[0043] In this exemplary embodiment, three cam follower pins 75, three corresponding cam slots 80a, 90a, and three corresponding retention slots 110a are used for force balancing purposes. Other numbers of cam follower pins, cam slots, and retention slots may be used in other embodiments.

[0044] The planetary gearbox 95, shown in partially exploded form in Figure 4A, is shown further exploded in Figure 4B. This exemplary planetary gearbox 95 includes a planetary gear carrier 115, a plurality of planetary gears 120, a cap 125 (only as part of the gearbox housing), a sun gear 130, a ring gear 135, and a gearbox output shaft 100. Consists of As shown, the planetary gear carrier 115 may be an integral part of the gearbox input 85 or the planetary gear carrier may be affixed to the distal end of the gearbox input 85 . Similarly, sun gear 13 may be an integral part of gearbox output shaft 100 or may be affixed to the proximal end of gearbox output shaft 100 . The various components of planetary gearbox 95 are housed within the gearbox housing. In this exemplary embodiment, the housing is comprised of a ring gear 135 and a cap 125 that are snap-fitted together to form a substantially monolithic structure. or otherwise adapted to be joined.

[0045] In this exemplary embodiment, the planetary gearbox 95 is a single stage planetary gearbox. Generally speaking, therefore, when the planetary gearbox 95 is selectively engaged, the speed with which the volume of the quick-set pipette 5 can be adjusted is determined by the speed ratio provided by the planetary gearbox 95. Increased. A wide range of planetary gearbox speed ratios may be selected in various exemplary embodiments. Merely by way of example, the speed ratio provided by the planetary gearbox 95 of this exemplary quick-set pipette 5 is 4:1.

[0046] The plunger button 30 and plunger rod 25 of the quick-set pipette 5 also play a role in the operation of the quick-set mechanism 65. More specifically, the plunger rod 25 passes through and is rotatably coupled to the gearbox input 85 of the planetary gearbox 95 of the quickset mechanism 65 and the plunger button 30 is positioned near the plunger rod. It is affixed to the tip so that rotation of the plunger button will also rotate the plunger rod. In this exemplary embodiment, the rotatable attachment of plunger rod 25 to gearbox input 85 includes a hexagonal (or other non-circular shaped) protrusion 140 on the plunger rod and the hexagonal and a correspondingly shaped recess 145 at the proximal end of the gearbox input that is sized to fixedly receive and retain the protrusion of the gearbox input. Other rotatable coupling techniques may be employed in other embodiments. As a result, rotation of the plunger button 30 will cause the plunger rod 25 to rotate, and rotation of the plunger rod will cause the gearbox input 85 to rotate.

[0047] As briefly mentioned above, when the exemplary quickset mechanism 65 is assembled, the velocity increasing barrel cam 90 is located concentrically within the direct drive barrel cam 80 such that the transmission input 70 The distal portion is received therein and one or more cam follower pins 75 projecting from the transmission input device 70 are coupled simultaneously with one or more cam slots 80a in the direct drive barrel cam 80 and velocity increasing pins 80a. It extends through one or more cam slots 90 a in barrel cam 90 and one or more cam slots 110 a in frame 110 . Axial motion of one or more cam follower pins 75 is constrained by slots 110a in frame 110, whereas rotational motion of one or more cam follower pins is restricted by slots in the frame. The engagement of one or more cam follower pins 75 with slots 110a in frame 110 constrains transmission input device 70 axially and limits rotationally. As a result, rotation of transmission input device 70 via lever 165 within the permitted range causes one or more cam follower pins 75 to rotate within arcuate or sloped cam slots 80a, 90a, 110a. , which displaces the barrel cams 80, 90 axially.

[0048] The gearbox input device 85 can have a variety of designs, including, but not limited to, the elongated substantially hollow shaft shown in the drawings. Gearbox input 85 transmits the rotation of plunger rod 25 (see above) to planetary gear carrier 115 of planetary gearbox 95 . The gearbox input 85 is axially constrained by the gearbox housing 175 and is not rotationally restricted.

[0049] As described above, the gearbox housing 175 is an assembly that includes the ring gear 135 and the cap 125. As shown in FIG. Cap 125 may be affixed to ring gear 135 by a wide variety of techniques, including but not limited to splines and snap fits. Because the ring gear 135 forms part of the gearbox housing 175 in this exemplary planetary gearbox 95 embodiment, the ring gear is prevented from rotating whenever the gearbox housing is constrained against rotation. constrained by

Ring gear 135 is the gear with internal teeth 180 of planetary gearbox 95 . In this exemplary embodiment, ring gear 135 further has gear teeth 185 formed in or affixed to the bottom surface of ring gear 135 . These gear teeth 185 form gearbox housing bottom gears 190 . Similarly, cap 125 has gear teeth 195 formed in or affixed to the top surface of cap 125 . These gear teeth 195 form gearbox housing top gears 200 . Thus, in addition to the internal gearing (ie, teeth 180 ) of ring gear 135 , gearbox housing 175 also provides lower gear 190 and upper gear 200 .

[0051] Velocity increasing barrel cam 90 has gear teeth 90b extending from its bottom, thereby forming velocity increasing barrel cam lower gear 205. As shown in FIG. The speed increasing barrel cam lower gear 205 is designed to engage matching teeth of the upper gear 200 of the gearbox housing 175 when the quickset mechanism 65 is in direct drive or lock mode. The velocity-increasing barrel cam is rotationally constrained by a direct-drive barrel cam 80 with a velocity-increasing barrel cam 90 nested inside the direct-drive barrel cam 80 in this exemplary quickset mechanism 65 . Velocity-increasing barrel cam 90 is further axially limited by movement of one or more cam follower pins 75 .

[0052] As noted above, in the exemplary quickset mechanism 65 shown and described herein, the velocity increasing barrel cam 90 nests within the direct drive barrel cam 80 . However, in other exemplary quickset mechanism embodiments, the relationship between the direct drive barrel cam 80 and the velocity increasing barrel cam 90 may be reversed, or both barrel cams may be arranged axially in succession. may be

[0053] The direct drive lock plate 105 of the quickset mechanism 65 has an axial opening 210 that allows the gearbox output shaft 100 to pass therethrough. The opening 210 and gearbox output shaft 100 can have corresponding non-circular shapes, or the direct drive lock plate 105 can be keyed or otherwise affixed to the gearbox output shaft, As a result, the direct drive lock plate and gearbox output shaft are rotatably coupled (ie, the lock plate cannot rotate on the gearbox output shaft). The direct drive lock plate 105 is not rotationally restricted, but is axially restricted by the arm 80b of the direct drive barrel cam 80. As shown in FIG. As a result, direct drive barrel cam 80 controls the axial position of direct drive locking plate 105 .

[0054] The direct drive lock plate 105 further has gear teeth 215 formed in or affixed to the top surface of the direct drive lock plate 105. As shown in FIG. These gear teeth 215 form the direct drive lock plate top gear 220 . Direct drive lock plate top gear 220 is designed to engage matching gear teeth 185 of gearbox housing bottom gear 190 .

[0055] Because the direct drive lock plate 105 is rotatably coupled to the gearbox output shaft 100, when the quickset mechanism 65 (and direct drive lock plate 105) is in the direct drive mode, the gearbox housing 175 Engagement of the direct drive lock plate top gear 220 to the bottom gear 190 secures the ring gear 135 to the gearbox output shaft. When not in direct drive mode, the direct drive lock plate 105 is idle and free to rotate with the gearbox output shaft 100 .

[0056] In addition to being rotationally limited by the direct drive lock plate 105 when the direct drive lock plate is engaged to the gearbox housing 175, the gearbox output shaft 100 also includes a sun gear 130. It is axially constrained by the gearbox housing, such as by a flange or similar feature located distally of the gearbox housing. Gearbox output shaft 100 may be attached to sun gear 130 or may be an extension of sun gear 130 .

[0057] A gearbox output shaft 100 transmits direct or increased velocity user rotation of the plunger button 30 to the volume screw 50 . The volume screw 50 threadably engages a corresponding threaded retaining element located within and fixed to the pipette body 10 such that rotation of the volume screw pivots the volume screw relative to the pipette body. direction is displaced. Because the underside of volume screw 50 serves as the upper stop for the plunger assembly in this exemplary quick-set pipette 5, axial displacement of volume screw 50 changes the overall plunger stroke by , adjust the pipette volume.

[0058] A frame 110 houses a number of quickset mechanism components, constrains the rotation of the direct drive barrel cam 80, functions as a rotating bushing for the planetary gearbox 95, and one or more cam follower pins. 75 is rotationally limited to axially constrain one or more cam follower pins. A frame 110 is fixed to the pipette body 10 both axially and rotationally.

[0059] Mode selection using transmission input 70 of quickset mechanism 65 serves to change the constraint of planetary gearbox 95 between locked and unlocked states. In speed up mode, the planetary gearbox is unlocked (operable). The reason for this is that the ring gear 135 (which also functions as part of the planetary gearbox housing) is fixed to the frame 110 and the gearbox output shaft 100 is not constrained thereby allowing the internal planetary gear components to move. This is because rotation becomes possible. Because the input device to the planetary gearbox 95 in this exemplary embodiment is the planetary gear carrier 115, the output device is the sun gear 130, and the ring gear 135 is fixed to the frame 110, A planetary gearbox 95 acts as a speed multiplier when unlocked. More specifically, carrier 115 and planetary gear 120 (rotatably mounted on the carrier) will rotate within fixed ring gear 135 . Rotation of planetary gears 120 in this manner results in rotation of sun gear 130, but at an increased speed, and in this exemplary embodiment, rotation of gearbox input 85 and planetary gear carrier 115. At a rotational speed that is four times the speed. Thus, the rotational speed (input) of the planetary gear carrier 115 caused by rotation of the plunger button 30 and plunger rod 25 by the user is increased by the planetary gearbox 95 and then applied to the volume screw 50 by the sun gear 130 and gearbox output shaft 100 . transmitted. Therefore, the volume screw 50 will rotate faster than the plunger button 30 is rotated by the user.

[0060] In contrast, if any two of the planetary gearbox input, ring gear 135, and output are fixed together, the planetary gearbox 95 is locked (disabled), which , means that no relative motion can occur between any of the components in the planetary gearbox (ignoring backlash). In this exemplary embodiment, the locked condition of planetary gearbox 95 results from both ring gear 135 being fixed to frame 110 and gearbox output shaft 100 being fixed to the ring gear. .

[0061] In the direct drive mode, the gearbox output shaft 100 is fixed to the ring gear 135 and the ring gear is spaced from the frame 110. As a result, in direct drive mode, the entire planetary gearbox 95 will rotate with the plunger button 30 and plunger rod 25 .

[0062] Referring to Figures 5A-5C, where the frame 110 has been omitted for clarity, the movement and interaction of the various components of the exemplary quick set mechanism 95 when positioned in each mode of operation. The action can be better understood. In FIGS. 5A-5C, FIG. 5A shows an exemplary quickset mechanism 65 in lock mode, which prevents pipette volume adjustment, and FIG. 5B shows quickset mechanism 65 in direct drive mode (1:1 speed ratio). Fig. 5C shows the quickset mechanism in an increased speed mode (eg, 4:1 speed ratio).

[0063] The exemplary quickset mechanism 65 is shown in the locked mode in FIG. 5A. When transmission input 70 is placed in the locked mode, movement of one or more cam follower pins 75 within one or more cam follower slots 80a of direct drive barrel cam 80 forces the direct drive barrel cam upward. , thereby also moving the direct drive lock plate 105 upward so that the direct drive lock plate top gear 220 engages the gearbox housing bottom gear 190 . Because the direct drive lock plate 105 and the gearbox output shaft 100 are rotatably coupled, the engagement of the direct drive lock plate upper surface gear 220 and the gearbox housing lower surface gear 190 causes the gearbox output shaft 100 to rotate into the gearbox housing. 175, which prevents rotation of the internal planetary gear components.

[0064] Movement of the one or more cam follower pins 75 when the transmission input 70 is placed in the locked mode will cause the direct drive barrel cam to move upward, while this same Pin movement simultaneously causes a velocity-increasing barrel cam 90 nested within the direct drive barrel cam 80 to move downward. This downward movement of the speed increasing barrel cam 90 causes the speed increasing barrel cam bottom gear 205 to engage the gearbox housing top gear 200 , thereby effectively locking the planetary gearbox 95 to the frame 110 . Simultaneous engagement of lock plate top gear 220 with gearbox housing bottom gear 190 and engagement of speed increasing barrel cam bottom gear 205 with gearbox housing top gear 200 causes plunger button 30 and plunger Any rotation of rod 25 and volume screw 50 is prevented, thereby locking quickset pipette 5 .

[0065] Referring now to FIG. 5B, the quickset mechanism 65 is placed in the direct drive mode by correspondingly rotating the transmission input device 70 to the appropriate position using the lever 165. As shown in FIG. When transmission input 70 is rotated to direct drive mode, the resulting movement of one or more cam follower pins 75 within one or more cam follower slots 80a of direct drive barrel cam 80 causes: The direct drive barrel cam is moved upward, which simultaneously moves the direct drive lock plate 105 also upward, causing the lock plate top gear 220 to engage the gearbox housing bottom gear 190 . Because the direct drive lock plate 105 and the gear output shaft 100 are rotatably coupled, the engagement of the direct drive lock plate upper surface gear 220 and the gearbox housing lower surface gear 190 causes the gearbox output shaft 100 to move into the gearbox housing 175. to prevent rotation of the internal planetary gearbox components.

[0066] The above-referenced rotation of transmission input device 70 and resulting movement of one or more cam follower pins 75 further causes velocity-enhancing barrel cam 90 nested within direct-drive barrel cam 80 to increase velocity. be moved upwards. This upward movement of the speed increasing barrel cam 90 disengages the speed increasing barrel cam bottom gear 205 from the gearbox housing top gear 200 . The disengaged velocity-increasing barrel cam 90 is thereby idle in direct drive mode, whereas the planetary gearbox 95 is substantially a rigid coupling between the plunger rod 25 and the gearbox output shaft 100; Rotates freely with the plunger rod. As a result, rotation of plunger button 30 and attached plunger rod 25 causes volume screw 50 to likewise rotate (1:1).

[0067] Referring now to FIG. 5C, the quickset mechanism 65 is placed in the increased speed mode by correspondingly rotating the transmission input device 70 to the appropriate position using the lever 165. As shown in FIG. When the transmission input device 70 is rotated to the increased velocity mode, the resulting movement of the one or more cam follower pins 75 within the one or more cam follower slots 80a of the direct drive barrel cam 80 causes: The direct drive barrel cam is moved downward, which simultaneously moves the direct drive lock plate 105 downward as well, disengaging the lock plate top gear 220 from the gearbox housing bottom gear 190 . This puts the lock plate in an idle state.

[0068] The above-referenced rotation of transmission input device 70 and resulting movement of one or more cam follower pins 75 further provides a velocity increasing barrel cam 90 nested within direct drive barrel cam 80. move downwards. This downward movement of speed increasing barrel cam 90 causes speed increasing barrel cam bottom gear 205 to engage gearbox housing top gear 200 , thereby effectively locking ring gear 135 to frame 110 . , allowing rotation of the planetary gear components. As a result, rotation of plunger button 30 and attached plunger rod 25 causes volume screw 50 to rotate at an increased rotational speed (eg, 4:1).

[0069] There is no need for the user to put the quickset pipette 5 into speed increasing mode when making volume adjustments. However, in those instances where the user wishes to use the increased speed mode to speed up volume adjustment, the user must first place the lever 165 of the quickset mechanism transmission unit 70 in the increased speed position. to set the speed increase mode. Each of the increased velocity positions (as well as the direct drive position and the locked position) are on the pipette body 10 and/or by detents (also called detents or ratchet wheels) that provide tactile feedback to the user. is defined by the notation Subsequent rotations of the plunger button 30 then effect an increased speed rotation of the volume screw 50 and a corresponding coarse volume adjustment. When the volume of the quick-set pipette 5 approaches the desired volume, the user can switch the quick-set mechanism 95 to direct drive mode by placing the lever 165 of the transmission unit 70 in the direct drive position. Subsequent rotation of the plunger button 30 then effects a 1:1 rotation of the volume screw 50 and a corresponding fine volume adjustment. Utilization of both increased velocity and direct drive modes allows for quick and accurate pipette volume setting. Once the desired pipette volume is set, the user can prevent inadvertent adjustment or deviation of the volume setting by placing lever 165 of transmission unit 70 in the locked position.

[0070] To further facilitate volume setting, the quickset pipette 5 is equipped with an exemplary volume setting display assembly 400. As shown in FIG. The volume setting display assembly 400 of this exemplary quick-set pipette 5 consists of a series of numbered counterwheels 225 coupled to the volume adjustment assembly of the pipette. More specifically, counter wheel 225 is rotatably coupled to volume screw 50 via a gearing. In this case, rotation of the plunger button 30 and volume screw 50 results in corresponding rotation of the counterwheel 225 so that the numerical reading provided by the counterwheel indicates the current volume setting of the pipette. It will be. As explained above, counterwheel 225 is visible through opening 60 in pipette body 10 . Other pipette embodiments may substitute the counterwheel volume setting display assembly 400 of the quick-set pipette 5 with an electronic volume setting display and corresponding volume detection sensor, or the like.

[0071] The quickset pipette 5 of FIG. 1 is further depicted in FIG. 6 after volume adjustments have been made. In this case, the volume of the quickset pipette 5 shown in FIG. 6 is reduced compared to the volume of the quickset pipette 5 shown in FIG. Thus, plunger button 30, plunger rod 25 and associated flange 380, piston 20, and volume screw 50 have all been moved distally within pipette body 10, and stroke spring 35 is compressed. can notice. The distal displacement position of the bottom surface of volume screw 50 defines the new plunger unit upper stop position.

[0072] As explained above, accurate pipetting requires calibration of the dispensed fluid volume. Thus, pipettes are typically calibrated at the factory and can be recalibrated later, such as during maintenance work.

[0073] Pipette calibration is typically performed using distilled water. Therefore, a pipette user may wish to enter a factory volume offset when pipetting fluids of different densities than that of distilled water. Similarly, it may be desirable to enter a factory volume offset when pipetting at atmospheric conditions that differ from standard temperature and pressure (STP), such as high altitude (high altitude). .

[0074] To this end, the exemplary quickset pipette 5 further comprises a calibration/offset mechanism 250. As shown in FIG. One exemplary embodiment of such a calibration/offset mechanism is detailed in FIGS. 7A-9.

[0075] As shown in FIGS. 7A-7B, the exemplary calibration/offset mechanism 250 performs mode selection in the form of a mode selector barrel cam as a schematic order of appearance in the proximal to distal direction. a mechanism (i.e., barrel cam input) 255; a driven element in the form of a driven barrel cam (i.e., barrel cam follower) coupled to barrel cam input 255 so as to be axially displaceable in response to movement of the barrel cam input; an offset counter 265; a user-rotatable input mechanism in the form of a pinion gear 270; and a calibration/offset mechanism 250 for the purpose of increasing or decreasing the liquid volume of the pipette. offset with respect to an axially displaceable screw element 510 (in this embodiment the housing of the blowout assembly 500) that can be selectively axially displaced to adjust the home position of the pipette where it is and a coupling device 275 for coupling the counter 265 . When the calibration/offset mechanism 250 is in the assembled state as shown in FIG. 8B, the above components of the calibration/offset mechanism 250 are substantially retained within the (calibration) housing 280 .

[0076] In addition to the calibration/offset mechanism 250, FIGS. 7A-7B and 8B illustrate various components of the volume setting display assembly 400. FIG. This exemplary volume setting display assembly 400 is shown with the volume screw 50 referred to above and a counter wheel 255 providing a numerical display of the pipette volume that has been set. The volume setting display assembly 400 further includes a mounting plate 405 having an opening through which the volume screw 50 passes which is adapted to receive and support the counter wheel 255 and associated gearing assembly. The mounting plate 405 may be a component of the volume setting display assembly 400 or a component of the calibration/offset mechanism 250, but is still affixed (such as by press fit) to the calibration housing 280 and the barrel cam input device of the calibration/offset mechanism. Acts as the upper axial limit for 255.

[0077] Volume screw 50 also passes through transmission gear 410, which rotates on the top surface of mounting plate 405. Transmission gear 410 has tabs 415 that engage corresponding slots on volume screw 50 so that rotation of the volume screw causes rotation of the transmission gear. A cluster gear 420 is interposed between the transmission gear 410 and the counterwheel gearing so that rotation of the volume screw 50 causes volume indicating rotation of the counterwheel 225 .

[0078] Barrel cam input 255 of calibration/offset mechanism 250 is partially nested within barrel cam follower 260, but extends upwardly from barrel cam follower 260 some distance. Barrel cam input device 255 has a mode selector element such as selector lever 285 or similar actuator accessible through calibration/offset aperture 290 in pipette body 10 . A mode selection lever may be used to select calibration or offset modes of calibration/offset mechanism 250 by rotating barrel cam input device 255, as will be described in greater detail below.

[0079] As noted above, the driven element (barrel cam follower) 260 of the exemplary calibration/offset mechanism 250 can be axially displaced in response to movement of the mode selection mechanism (barrel cam input device 255). can. To this end, in this particular embodiment one or more arcuate or sloped cam slots 295 are provided on the outer surface of barrel cam input 255 and extend inwardly from the inner surface of barrel cam follower 260. are arranged and designed to be engaged with one or more cam follower pins 300 . As a result, rotation of barrel cam input 255 via selector lever 285 causes axial displacement of the barrel cam follower. The design of the mode selection mechanism and driven element may differ in other embodiments, in which case the driven element may be axially displaced by action of the mode selection mechanism other than rotation.

[0080] The barrel cam input 255 of this exemplary embodiment is limited (within a certain angular range) in the direction of rotation. Barrel cam input 255 is further axially limited by calibration housing 280 and mounting plate 405 .

[0081] Barrel cam follower 260 is interposed between barrel cam input device 255 and calibration housing 280, and downwardly extending arm 305 designed to engage slot structure 310 in calibration housing 280. have An offset counter-rotating groove 315 may be provided on the interior surface of barrel cam follower arm 350 . One or more cam follower pins 300 can be seen extending inwardly from barrel cam follower 260 as described above.

[0082] An offset counter 265 displays the magnitude and direction of any volume offset input by the user, such as through a series of positive and negative numbers printed along its circumference. When the calibration/offset mechanism 250 is assembled, the offset counter 265 is retained within the calibration housing 280 and is free to rotate within the calibration housing 280, rotating within such as the offset counter rotation groove 315 of the barrel cam follower 260. do. In this manner, the offset counter 265 is axially limited by the barrel cam follower 260 (ie, moves axially with the barrel cam follower 260), but is not rotationally limited by the barrel cam follower.

[0083] An offset counter 265 is fitted over the upper section of coupling device 275 and is optionally rotatably coupled to or rotated from the upper section of coupling device 275 as further described below. separated as possible. Offset counter 265 may have a slot 265a, recess, or other similar structure in its top surface that is selectively engageable with a corresponding male structure of another offset counter component. . For example, the underside of the top surface of calibration housing 280 can have such structures. If the offset counter slot 265a is not aligned with the male structure, the male structure will block upward movement of the offset counter 265, but through the insertion of the male structure into the slot. allows upward movement when alignment is performed. Alignment of the male structure with the slot 265a of the offset counter 265 is configured to occur only when setting the offset counter to the "zero" position so that the current pipette calibration setting is in the offset state. , the offset counter is prevented from being disconnected and the calibration operation is prevented from being performed.

[0084] To rotatably couple the offset counter 265 to the coupling device 275, the offset counter is an internal gear designed to engage mating gear teeth or splines 370 on the coupling device's outer surface. It can have teeth or splines 320 . In other embodiments, offset counter 265 and coupling device 275 may have corresponding tapered portions or may be equipped with some other structure so that calibration/offset mechanism 250 is placed in offset mode. Ensure that the offset counter and coupling device rotate together when set.

[0085] When the calibration/offset mechanism 250 is set to the offset mode (the normal mode of the calibration/offset mechanism), the coupling device 275 rotatably couples the offset counter 265 to the blowout assembly 500 and the pinion gear 270 to the blowout assembly housing 510 of the blowout assembly 500 . The offset counter can be separate from the blowout assembly, allowing factory calibration (in calibration mode). Accordingly, alignment adjustments to the blowout assembly 500 will be communicated to and indicated by the offset counter during offset input by the user, but are made during factory calibration (or recalibration). can't break Coupling device 275 has a vertical slot 325 in its lower section to receive alignment and engagement arm 520 of blowout assembly housing 510 .

[0086] A pinion gear 270 that is not restricted in the direction of rotation is provided for converting user input into rotation of coupling device 275 . More specifically, pinion gear 270 converts rotation about an axis that is perpendicular to offset counter 265 and coupling 275 to rotation about the central axis of the offset counter and coupling. This allows the user to conveniently rotate coupling device 275 by engaging pinion gear 270 using a hex key or other suitable tool. Rotation of coupling device 275 by pinion gear 270 is caused by engaging the pinion gear with a corresponding miter gear 330 located on the coupling device.

[0087] The calibration housing 280 of this exemplary calibration/offset mechanism 250 is a substantially hollow cylinder. Calibration housing 280 has an axial opening 335 in its proximal end 280a for allowing passage of plunger rod 25; and for receiving downwardly extending arm 305 of barrel cam follower 260. a calibration viewport 340 for viewing the numbers printed on the offset counter 265; and engagement and rotation of the pinion gear 270 through the calibration housing. and a pinion gear access opening 345 for enabling. The calibration housing 280 may further have one or more slots 350 or similar apertures through which corresponding clips 355 or equivalent retaining elements are inserted into one or more configurations of the calibration/offset mechanism 250. Can be inserted to hold elements. For example, clip 355 may be inserted into slot 350 in calibration housing 280 and thereby engage retention groove 360 in coupling device 275, thereby axially constraining the coupling device within the calibration housing.

[0088] Calibration housing 280 further includes internal threads 365 (see FIG. 9). Female threads 365 are provided for mating with male threads 515 at the proximal end of the threaded element of blowout assembly 500 (blowout assembly housing 510), so that the blowout assembly housing and the calibration housing can be assembled with threaded engagement. Calibration housing 280 also serves as a positional reference point for calibration and is fixed relative to pipette body 10 in all degrees of freedom.

Blowout assembly 500 has blowout piston 505 located within blowout assembly housing 510 along with blowout spring 45 . A blowout spring 45 is located below the blowout piston 505 so that the blowout piston is biased towards the proximal end of the quickset pipette 5 and the upper stop position.

[0090] External threads 515 are present at the proximal end 510a of the blowout assembly housing 510. As shown in FIG. External threads 515 on blowout assembly housing 510 are provided to engage corresponding internal threads 365 in calibration housing 280, as described above. Thus, when the calibration/offset mechanism 250 is assembled, screwing the blowout assembly housing into or out of the calibration housing causes the blowout assembly housing 510 to move axially relative to the calibration housing 280 . can be displaced to

[0091] A blowout assembly housing 510 extends upwardly sized and arranged to fit within a slot 325 in the lower portion of coupling device 275 in an interfitting fashion. It also has an alignment arm 520 . This interfitting assembly rotatably couples the blowout assembly housing 510 to the coupling device 275 so that when the coupling device is rotated by the pinion gear 275, the blowout assembly housing is compliant. It will rotate and at the same time allow axial movement of the blowout assembly housing relative to the coupling device.

[0092] The home position of the quickset pipette 5 can be defined as the position when the stroke spring 40 is fully compressed by the pipette piston 20 and the volume of aspirated liquid has been completely dispensed, but here blow-out. No compression of the throttle and blowout springs 45 has been initiated. In this exemplary embodiment, the plunger rod 25 will contact the top surface of the blowout piston 505 of the blowout assembly 500 when the plunger rod is in its home position (and when the plunger rod is in its upper stop position). , which will contact the bottom surface of the volume screw 50). Calibrating the pipette volume or entering a volume offset moves the axial position of the blowout assembly 500 (including the blowout spring 45) to increase or decrease the liquid volume of the pipette. can be achieved in the form

[0093] When the calibration/offset mechanism 250 is fully assembled, the barrel cam input device 255 is both rotationally and axially constrained; the barrel cam follower 260 is rotationally constrained by the calibration housing 280 and one or axially limited by movement of a plurality of cam follower pins 285; coupling device 275 axially constrained within the calibration housing but free to rotate; Axially constrained as a reference but movable with barrel cam follower 260, it is rotatably coupled to coupling device 275 when setting calibration/offset mechanism 250 in the offset mode to calibrate the calibration/offset mechanism. rotatably separated from the coupling device when setting the mode; pinion gear 270 is axially constrained but not rotationally restricted by calibration housing 280; blowout assembly 500 is rotationally coupled by the coupling device; , but is free to move axially relative to the coupling device, and further axially by engagement of external threads 515 on blowout assembly housing 510 and corresponding internal threads 365 in calibration housing 280. is bounded (but not constrained) in

[0094] A mode selection lever 285 of the barrel cam input device 255 is used to select a calibration mode or an offset mode of the calibration/offset mechanism 250. As shown in FIG. Normally, the default calibration/offset mechanism 250 is in offset mode so that any user adjustment of pinion gear 270 is indicated by offset counter 265 .

[0095] To enter a volume offset, the user first either has the calibration/offset mechanism 250 already set to the offset mode, or presses the mode selection lever of the barrel cam input device 255 to select the offset mode. 285. When the mode select lever 285 of the barrel cam input 255 is placed in the offset mode, the barrel cam follower 260 rotates within one or more cam slots 295 on the outer surface of the barrel cam input 255 . Movement of the child's one or more cam follower pins 300 causes downward movement. This downward movement of barrel cam follower 260 causes offset counter 265 to likewise move downward, and offset counter 265 is pivoted relative to barrel cam follower 260 by offset counter rotary groove 315 in barrel cam follower arm 305 . Constrained in direction. Offset counter 265 is thereby rotatably coupled to coupling device 275 .

[0096] The volume offset of the quickset pipette 5 then extends a hex key or other suitable tool through the calibration/offset aperture 290 in the pipette body 10 and through the pinion gear access opening 345 in the calibration housing 280. , thereby engaging pinion gear 270 to rotate in one direction or the other, thereby entering the desired negative or positive volume offset. Rotation of pinion gear 270 causes rotation of coupling device 275 , which correspondingly rotates blowout assembly housing 510 which is rotatably coupled to coupling device 275 . Rotation of the blowout assembly housing 510 will displace the blowout assembly 500 axially upward (in the threading direction) or downward (in the releasing direction) relative to the calibration housing 280 and the pipette body 10; This will move the home position of the pipette and change the volume of liquid that can be aspirated by the pipette.

[0097] Because the offset counter 265 is rotatably coupled to the coupling device 275, when the user rotates the pinion gear 270 in the offset mode, the offset counter will rotate with the coupling device. As a result, the magnitude of the offset being entered is indicated by the offset counter 265 and can be viewed by the user through the calibration viewport 340 in the calibration housing, which is viewable through the calibration/offset aperture 290 in the pipette body 10. be.

[0098] To perform a factory calibration or recalibration, the user operates the mode selection lever 285 of the barrel cam input device 255 to select the calibration mode. One or more of the rotating barrel cam followers within one or more cam slots 295 on the outer surface of the barrel cam input device 255 when the mode selection lever 285 of the barrel cam input device 255 is placed in the calibration mode. Movement of cam follower pin 300 causes barrel cam follower 260 to move upward. This upward movement of barrel cam follower 260 causes offset counter 265 to likewise move upward, and offset counter 265 is moved relative to barrel cam follower 260 by offset counter rotary groove 315 in barrel cam follower arm 305 . Constrained in the axial direction. Offset counter 265 is thereby rotatably separated from coupling device 275 . As noted above, prevent the calibration/offset mechanism from selecting the calibration mode (and isolating the offset counter 265 from the coupling device 275) unless the offset counter 265 is set to the "zero" position. can have a structure for This prevents the calibration operation from being inadvertently performed with the volume offset already entered for the pipette 5 .

[0099] Calibration or recalibration of the quickset pipette 5 is then performed by inserting a hex key or other suitable tool through the calibration/offset aperture 290 in the pipette body 10 and through the pinion gear access opening 345 in the calibration housing 280. This is accomplished by extending and thereby engaging pinion gear 270 to rotate in one direction or the other. In addition, rotation of pinion gear 270 causes rotation of coupling device 275, which results in corresponding rotation of blowout assembly housing 510, and blowout assembly relative to calibration housing 280 and pipette body 10. 500 will be displaced axially upwards (in the screwing direction) or downwards (in the releasing direction), which will move the home position and change the liquid volume of the pipette as desired. .

[00100] Because the offset counter 265 is rotatably separated from the coupling device 275 in calibration mode, the offset counter cannot be viewed through the calibration viewport 340 and the user rotates the pinion gear 270. , it does not rotate with the coupling device. As a result, offset counter 265 does not reflect any changes in pipette volume that occur during calibration or recalibration operations.

[00101] An alternative exemplary embodiment of a pipette quickset volume adjustment mechanism 600 is shown in Figures 10A-12. This quickset volume adjustment mechanism 600 is designed to be mounted within the body 605 of the pipette, similar to the exemplary quickset volume adjustment mechanisms described above. To this end, a pair of upper mounting elements 610 and a pair of upper mounting elements 610 that can be shaped and dimensioned to correspond to the inner wall of a given pipette body 605 in which the quickset volume adjustment mechanism 600 is to be mounted. It has a lower mounting element 615 . In other embodiments, a greater or lesser number of such locating elements may be employed, the locating elements having shapes or dimensions different from those shown in FIGS. 10A-12. good too.

[00102] The pipette into which the exemplary quickset volume adjustment mechanism 600 is mounted may be similar to the exemplary pipettes described above. That is, the pipette has, for example, a body portion 605 for being gripped by a user, a distal tip mounting portion adapted to receive and hold a pipette tip, and a body portion reciprocatable within the body portion. and a plunger rod extending proximally upwardly from the piston, and affixed to the proximal end of the plunger rod disposed outside the body portion for manipulation by a user. and a plunger button. Again, a stroke spring may be present in the body portion to drive the piston proximally during the liquid aspirating phase of the pipetting operation, and a blowout spring after the aspirated liquid has been dispensed from the pipette. It may be present in the body portion to retract the piston from possible blowout motion. Pipettes may additionally have other features such as, but not limited to, a tip ejector, volume adjustment assembly, volume setting display assembly, and calibration/offset mechanism. As a result, the pipette can operate in a general fashion (as described above) to aspirate and dispense a volume of liquid of interest.

[00103] As noted above, the exemplary quickset volume adjustment mechanism 600 adjusts the aspirable pipette volume because volume changes between successive aspirate/dispense operations can be significant. can be used to selectively increase the speed at which the 10A-12, the quickset volume adjustment mechanism 600 selectively interacts with a rotatable user input element 620 that can be used to adjust pipette volume. A gear train 625 (described in more detail below) that includes gears, an input shaft 630 that transmits rotation of the user input element 620 to the gear train, and a pipette volume screw on which the volume adjustment mechanism is mounted. (not shown) and an output shaft 635 to allow selection between at least a (direct) 1:1 volume setting mode and a speed increasing volume setting mode. and a pair of coupling elements 640, 645 operable to manipulate the gear train 625 in a vertical direction. The interaction of these components to achieve either direct mode or velocity-enhanced mode will be described in detail later.

[00104] As will be apparent to those skilled in the art, a plunger button or similar pipette actuator is present proximal to the user input element 620 when the quickset volume adjustment mechanism 600 is attached to the pipette body. become. For this purpose, the quickset volume adjustment mechanism 600 has an axial hole 650 in the user input element 620 through which a plunger rod can pass and which can be inserted into the plunger rod. has a plunger button attached to it. Referring to FIG. 12, similar cooperating axial holes 655, 660, 665, 670 further extend the input shaft 630, the input gear 700 of the gear train 625, the output gear 715 of the gear train, and the output gear 715, respectively. It can be seen that the shaft 635 passes through. Thus, the plunger rod serves as an alignment element for the various components of the quickset volume adjustment mechanism 600, while depression of the plunger rod via the plunger button also generally moves the piston of the pipette plunger assembly. can work to linearly displace

[00105] The gear train 625 of this exemplary quick-set volume adjustment mechanism 600 has four gears, and the selection and engagement of these four gears dictates the quick-volume adjustment mechanism in either the 1:1 mode or the increased speed mode. Decide whether to operate with In at least some embodiments, the gear train 625 may alternatively be set to be free-spinning and/or locked, in which case the quickset volume adjustment mechanism 600 is Placed in functional or locked mode.

11A and 12, it can be noted that the gear train has an input gear 700, a transmission gear 750, a speed increasing gear 710 and an output gear 715. FIG. Transmission gear 705 mates with input gear 700 and speed increasing gear 710 mates with output gear 715 . Transmission gear 705 and speed increasing gear 710 in this exemplary embodiment rotate on a separate shaft 675 extending between mounting elements 610 and 615 .

[00107] Speed increasing gear 710 has an integral spline coupling element 710a at its proximal end. Similarly, input gear 700 has an integral spline engagement element 700a at its distal end. A spline coupling element 710a allows an associated speed increasing gear 710 to selectively engage transmission gear 705 when it is desired to perform volume adjustments at increased speed. A splined coupling element 700b allows for selective engagement of the associated input gear 700 with the output gear 715 when it is desired to perform volume adjustments at a 1:1 speed.

[00108] A portion of each of the input shaft 630 and the input gear 700 pass through a hole 680 in the upper mounting element 610, as shown in FIG. The proximal end of input gear 700 is distally connected to input shaft 630, such as by using a corresponding hexagonal or other non-circular shape, or by other means as is well known to those skilled in the art. rotatably coupled to the extremity; Input gear 700 is rotatably coupled to input shaft 630 but is axially displaceable some distance along input shaft 630 . Accordingly, input gear 700 can be moved up and down relative to pipette body 5 , thereby selectively engaging or disengaging from output gear 715 . Given that the gear train is not placed in an optional locked state (described below), rotation of user input element 620 causes similar rotation of input gear 700 .

[00109] In a manner similar to that of input gear 700, speed increasing gear 710 is axially displaceable along shaft 675 some distance. Accordingly, speed increasing gear 710 can be moved up and down relative to pipette body 5 , thereby selectively engaging or disengaging transmission gear 705 .

[00110] A portion of the output shaft 635 passes through a hole 685 in the lower mounting element 615, as can be further noticed in FIG. Output shaft 635 is rotatably coupled at its proximal end to the distal end of output gear 715 such that rotation of output gear 715 causes output shaft 635 to rotate. The distal end of output gear 635 is shown adapted to connect to the volume screw of the pipette, thereby altering the aspirable liquid volume of the pipette when rotated, as described above.

[00111] As mentioned above, this example quickset volume adjustment mechanism 600 has a pair of coupling elements 640, 645 operable to set the state of the gear train 625. As shown in FIG. In at least some other embodiments, a single coupling element coupled to an appropriate gear of gear train 625 may be substituted for the separate coupling elements 640, 645 shown and described herein. may

[00112] In either case, a single connecting element or pair of connecting elements 640, 645 are located externally of the associated pipette so as to be accessible and operable by the user. Those skilled in the art will appreciate that it will be connected to multiple mode selection components (not shown). In some exemplary embodiments, the mode selection component causes a similar (coupled) upward or downward movement of a single coupling element or pair of coupling elements 640, 645. can be designed, thereby realizing a choice between only the direct volume setting mode or the speed increasing volume setting mode by setting the appropriate state of the gear train 625 in a corresponding manner. In other exemplary embodiments, such as where separate coupling elements 640, 645 are present here, the mode selection component provides selective independent movement of the coupling elements in both upward and downward directions. can be designed to allow Such a design allows gear train 625 to be set to additional locked and free-spinning conditions, allowing quickset volume adjustment mechanism 600 to be set to lock mode in addition to direct volume setting mode and speed increasing volume setting mode. Or allow it to be placed in non-functional mode. Mode selection in conjunction with associated coupling element movement and gear train conditions will be discussed in greater detail below.

[00113] In the drawings, both coupling elements 640, 645 are depicted in a downward position operating gear train 625 for illustrative purposes, so that quickset volume adjustment mechanism 600 is in direct drive (1:1) mode. is set to More specifically, placing the first coupling element 640 in the lower position causes the spline connector 700a of the input gear 700 to be engaged with the output gear 715, whereas placing the second coupling element 645 in the lower position. The spline connector 710a of the speed increasing gear 710 is disconnected from the transmission gear 705 by placing it in position. As a result, in direct drive mode, rotation of user input element 620 will cause rotation of both transmission gear 705 and output gear 715 . However, because the transmission gear 705 is disengaged from the speed increasing gear 710 , the transmission gear rotates in vain (idling), whereas the rotation of the output gear 715 causes the rotation of the user input element 620 . is caused directly by the input gear 700 in a 1:1 ratio to .

[00114] Conversely, placing both coupling elements 640, 645 in the upper position will operate gear train 625 to set quickset volume adjustment mechanism 600 to an increased speed mode. More specifically, placing the first coupling element 640 in the upper position disengages the spline connector 700a of the input gear 700 from the output gear 715, whereas placing the second coupling element 645 in the upper position. engages spline connector 710 a of speed increasing gear 710 with transmission gear 705 . Disengaging input gear 700 from output gear 715 prevents any direct rotation of the output gear by input gear (and user input element 620). Consequently, in the speed increasing mode, rotation of the user input element 620 causes rotation of the input gear 700, rotation of the input gear causes rotation of the transmission gear 705 and the speed increasing gear 710 engaged with the transmission gear 705, Rotation of the speed increasing gear causes output gear 715 to rotate. In this exemplary embodiment, setting the quickset volume adjustment mechanism 600 to the increased speed mode will cause the output gear 715 and output shaft 635 to rotate at twice the speed of the user input element 620. The pitch diameters of the various gears 700, 705, 710, 715 are selected such that the speed ratio of the gear train 625 in the speed increasing mode is 2:1. Other speed ratios are possible in other embodiments.

[00115] By placing the first coupling element 640 in the upper position and the second coupling element 645 in the lower position, the gear train 625 is placed in a free-spinning condition and the quickset volume adjustment mechanism 600 is set to non-functional mode. More specifically, the spline connector 700a of the input gear 700 is disengaged from the output gear 715 by placing the first coupling element 640 in the upper position, while the second coupling element 645 is placed in the lower position. Positioning disengages spline connector 710 a of speed increasing gear 710 from transmission gear 705 . As a result, in a free-spinning condition of gear train 625 , rotation of user input element 620 results in useless rotation of input gear 700 and transmission gear 705 . Since the speed increasing gear 710 and the output gear 715 are disengaged, they do not rotate, so when the user input element 620 rotates, the output shaft 635 does not rotate and the pipette volume setting is adjusted. Nothing is changed.

[00116] Finally, by placing the first coupling element 640 in the lower position and the second coupling element 645 in the upper position, the gear train 625 is locked and the quickset volume adjustment mechanism 600 is in the locked mode. is set to More specifically, the lower position of the first coupling element 640 causes the spline connector 700a of the input gear 700 to be engaged with the output gear 715, whereas the second coupling element 645 is placed in the lower position. The upper position causes spline connector 710 a of speed increasing gear 710 to engage transmission gear 705 . As a result, with all of gears 700, 705, 710, 715 of gear train 625 engaged, any rotation of user input element 620, gear train, or output shaft 635 is prohibited. Thus, in lock mode, the quickset volume adjustment mechanism 600 will be locked with respect to changing the pipette's aspirable liquid volume via rotation of the user input element 620 .

[00117] Other gear train configurations are possible in other similar exemplary quickset volume adjustment mechanism embodiments. For example, the total number of gears in the gear train may differ from the four gears shown in FIGS. 10A-12. The gear ratios of the gears used may also be different, whereby it is possible to obtain increased speed ratios higher or lower than 2:1. Other gear train modifications are also possible.

[00118] The one or more mode selection components external to or associated with the pipette body for operating the coupling elements 640, 645 can take many forms. For example, a mode selection component may facilitate upward and downward movement of a pivotable collar, a separate sliding or pivoting collar, one or more tabs or buttons, or a connecting element, without limitation. any other element or elements that can be connected to one coupling element or to multiple coupling elements 640, 645, etc., for the purpose.

[00119] As used herein, the term "distal" is intended to mean the end of the pipette where the pipette tip normally resides, and the term "proximal" is used to refer to the end of the pipette where the plunger button is located. It is intended to mean the end of the pipette where it is normally present.

[00120] As used herein, the term "axial" or "axially" is intended to mean a direction parallel to the longitudinal axis of the plunger rod when mounted in a pipette. .

[00121] As used herein, the term "central axis" is intended to mean the axis of symmetry of a component or pipette.
[00122] As used herein, the term "inferior" is intended to mean a direction proximal to distal with respect to the pipette, and the term "upper" is distal with respect to the pipette. It is intended to mean the side-to-proximal direction.

[00123] As used herein, "first" and "second" are intended only to identify two elements or two components for purposes of explanation, and may be any sort of order, priority, or It is not intended to indicate superordinate or subordinate.

[00124] Although specific exemplary embodiments of the pipette calibration and volume offset mechanism are described in detail above, the scope of the inventive concept is not deemed to be limited by such disclosure and is subject to the claims set forth below. Modifications as evidenced by the scope are also possible.

Claims (15)

A pipette calibration and volume offset mechanism (250), wherein said pipette calibration and volume offset mechanism (250):
a housing (280);
A mode selection mechanism (255) movable between a first position and a second position, said mode selection mechanism (255) pivoting at a proximal end of said housing (280). a mode selection mechanism (255) limited in direction and rotation;
an axially displaceable driven element (260) interposed between said mode selection mechanism (255) and said housing (280) and coupled to said mode selection mechanism (255);
an offset counter (265) for displaying a volume offset entered by a user, the offset counter (265) located within said housing ( 280 ) and axially movable with said driven element (260); )and;
a threaded element (510) located within said housing (280) having an axial position that is adjustable to define a home position of the pipette upon which said calibration and volume offset mechanism ( 250 ) is mounted;
A coupling device (275) located within said housing (280), wherein said coupling device (275) is rotatably coupled to said threaded element (510) to rotate said offset counter (265) to said threaded element (510). ) or operable to decouple said offset counter (265) from said threaded element (510);
An input mechanism (270) rotatable by a user rotatably coupled to said coupling device (275), such that rotation of said input mechanism (270) causes rotation of said coupling device (275). an input mechanism (270) comprising
said offset counter (265 ) does not rotate with said input mechanism (270) and said coupling device (275) when said mode selection mechanism (255) is in said first position;
when the mode selection mechanism (255 ) is in the second position, the offset counter (265) will rotate with the input mechanism (270) and the coupling device (275);
Pipette calibration and volume offset mechanism (250). A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
a mounting plate (405) is coupled to the proximal end of said housing (280);
said mode selection mechanism (255) is interposed between said mounting plate (405) and said housing (280);
Pipette calibration and volume offset mechanism (250). A pipette calibration and volume offset mechanism (250) according to claim 1 or 2, comprising:
A pipette calibration and volume offset mechanism (250), wherein both said mode selection mechanism (255) and said driven element (260) are barrel cams. A pipette calibration and volume offset mechanism (250) according to claim 3, comprising:
A pipette calibration and volume offset mechanism (250), wherein said mode selection barrel cam (255) is at least partially nested within said driven barrel cam (260). A pipette calibration and volume offset mechanism (250) according to claim 4, comprising:
said coupling of said driven barrel cam (260) to said mode selection barrel cam (255);
at least one arcuate or sloped cam slot (295) on the outer surface of said mode selection barrel cam (255);
at least one cam follower pin (300) extending inwardly from said driven barrel cam (260) and engaged with said at least one cam slot (295) in said mode selection barrel cam (255);
As a result, rotation of the mode selection barrel cam (255) causes axial displacement of the driven barrel cam (260).
Pipette calibration and volume offset mechanism (250). A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
A pipette wherein said offset counter (265) is rotatably coupled to said coupling device (275) by a mechanism selected from the group consisting of gear tooth or spline engagement and corresponding tapered portion engagement. Calibration and volume offset mechanism (250). A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
A pipette calibration and volume offset mechanism (250), wherein said user rotatable input mechanism (270) is a pinion gear. A pipette calibration and volume offset mechanism (250) according to claim 7, comprising:
The coupling device (275) has a miter gear (330) engaged with the pinion gear (270) to convert user rotation of the pinion gear (270) into rotation of the coupling device (275). Equipped, pipette calibration and volume offset mechanism (250). A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
A pipette calibration and volume offset mechanism (250) further comprising a viewpoint (340) within said housing (280) for observing a numerical value or other indication located on said offset counter (265). A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
A pipette calibration and volume offset mechanism (250) further comprising a user input mechanism access opening (345) in said housing (280) for allowing engagement and rotation of said user input mechanism (270). ). A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
A pipette calibration and volume offset mechanism (250) wherein upward axial movement of said offset counter (265) is inhibited when said offset counter (265) is in the offset position. A pipette calibration and volume offset mechanism (250) according to claim 1, comprising:
said threaded element (510) and said housing (280) are threadedly engaged;
rotation of the input mechanism (270) will rotate the threaded element (510) and axially displace the threaded element (510) with respect to the housing (280);
Pipette calibration and volume offset mechanism (250). 13. The pipette calibration and volume offset mechanism (250) of claim 12, comprising:
said threaded element (510) forming a housing for the blowout assembly (500);
said blowout assembly (500) further comprising a blowout piston (505) located within said blowout assembly housing (510);
A blowout spring (45) is located in the blowout assembly housing (510) distal to the blowout piston (505) such that the blowout piston (505) is pushed out of the housing (510). A pipette calibration and volume offset mechanism (250) biased toward the proximal end. 14. The pipette calibration and volume offset mechanism (250) of any one of claims 1 to 13, wherein when the mode selection mechanism (255) is in the first position, the pipette calibration and volume offset mechanism Pipette calibration and volume offset mechanism (250), wherein (250) is in calibration mode and said pipette calibration and volume offset mechanism (250) is in offset mode when said mode selection mechanism (255) is in said second position. ). 15. A pipette calibration and volume offset mechanism (250) according to claim 14, comprising:
rotation of the mode selection mechanism (255) causes axial displacement of the driven element (260);
When said mode selection mechanism (255) is positioned in said offset mode, said driven element (260) is positioned within one or more cam slots (295) on the outer surface of said mode selection mechanism (255). is moved downward by movement of one or more cam follower pins (300) of said driven element (260) in rotation,
downward movement of said driven element (260) causes said offset counter (265) to likewise move downward;
said driven element rotating within one or more said cam slots (295) on said outer surface of said mode selection mechanism (255) when said mode selection mechanism (255) is disposed in said calibration mode; movement of one or more of said cam follower pins (300) of (260) causes said driven element (260) to move upward;
upward movement of said driven element (260) causes said offset counter (265) to likewise move upward;
Rotation of said input mechanism (270) causes rotation of said coupling device (275), thereby correspondingly rotating said threaded element (510) rotatably coupled to said coupling device (275). and the rotation of said threaded element (510) will displace said threaded element (510) axially with respect to said housing (280) in the threading direction or in the releasing direction, thereby causing said home position of said pipette. A pipette calibration and volume offset mechanism (250) whose position will be moved to change the volume of liquid that can be aspirated by said pipette.

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