US2358936A - Pipette - Google Patents

Description

Sept.26, 1944. w. T. MATHls INVENTOR 144900)/ TMA H/s Filed May 27. 1941 or dispensing of the liquid Vis pro-vided.y r- A Patented Sept. 26, y1944 i .f

ration of NewYorl 1- y Application `May-27, 1941, Serial-'No;395,332" "f c l f1 v jiaiclal icl. zzz-5192),' v l y This invention relates'generallyto pipettesand- Y. 'ferring` and ydispensing fluids'and'.providedfwith similarlaboratoryaplparatus ofthe type employed fr suitable graduations Il fo'rmeasuringtht'z'quanl *Y for collecting, transferring or-J dispensing liquidsi i tity cfiiuid drawn into the tube Ill. Y f A It is Wellkngwn that in-,using .pipetteSicr col'r i. For creating a suction for the purpose of draw# *j lectingtransi`erring er1 i-dispensingtliquids; fthe-f 5i' ing fluid intothe tube;v Without danger t the -x customary practicevhasbeenjtcdraw the liquids' Si user, vIemploya'collapsiblerubber:bulb'|254 f'Ihe into .the 'pipette-v by means of` suctionrcreated byY said ybulb I2 is madewith 'aV tmckenedtb'ottdm the .IIlQuth and after withdrawing the tube from wallportionl |2a lprvided with an 'aperture I4 y the mouth to hold such liquid in the pipetteIby communicating With' the h'o-llcwnteriorof ftlief sealingv thetop end ofxthe tube byvther-th'iunb 'or -110 bulbi-2:y TheSuCtiOn bulb 'l2 `1'S Sllpliltf*Olii'i` iinger.Y n franflegl'fY comprising a base portion" |5a`jand ai Thereafter the transferring or dispensing of the* wall lilrupstanding Atherefromiilt islnot'ed that' liquidwas controlled by the pressure ofthe thumb 1- the inner surface "I6 of thelwall 15b ofthe frame or finger.. v .Y 1 r v l5is=concavedft0conform to theshape of the'bulb The above described customary practice Ypos-N15 I2 andA forms an abuttingsurface againstwhicli essesu inherent disadvantages among which are the the bulb I2 may be pressed 'to collapse the-'samei following.v Since theliquids, inconnection with vlfrojecting Voutwardly"fromithe'outer surlace of4 '.Mr which thepipettes are used are often of apoison f the wall-15b, is a Y'hook *shapedY finger holding ous or otherwise injurious natu-re this practice of jmemnber4 ILv Anipple member I8 threadedly resucking inliquids is fraught with great danger 20- ceivedV in the 'frame base 15a and. having an upf because the liquid is apt to loe-inadvertently drawnwardly Nprojecting tapered portion. la, friction-. into the mouthuofthe user. Alsc the above delally passing hroug'lrthe aperturejldgserves to s scribed manner of nger control isfeffcient and-- f hold vtl'ieflaullowlZ in effectiveposition. i sensitive only Whenpracticed by Onehighly skilled l Theusaid nipple portion 18a, terminates ingan Lil in itsjtechnique"'. r 'l f, *fge-zangularly'bent portion`2,0,-inclined in adirection i, fly' It vclellefrre onek of the pincpfl -objectsffo away from the framewall l 5b, and is further promy invention to provide a Idevicefior use'with a Vvided with a `ilaiztene*d1enr-l 2 l The purpose ,andl pipette' in which a suction for drawing4 in liquids 5; @function ciI the nipple porh 20;andendzl, will is obtainedwithout` any danger tc `the-user and Soon lcbmeapparent tithe descripticnproceeds., in which atgthe salme timenovel means forsensiv 30v Thfra'ni basic). [5u jsvproyidedwith an open?` J tivelyandefficiently ',controllingrthe .transferring` fing 23i'('xtriii'ginwmjqlyy @om mevmttom-Surr a f f face thereof. A'resilientliningvmember 2,4,.in A Anothercbject of my inventienisto providea 1-Nthe sdpe'ning 23 frictionally, receives, the upc-1, device of the class described in which pipettes per open end of the tube AlzrllthereinLas; clearly@ of relatiyelylarge size may.be:automatically-filled 35""shovvn`l inFi'gf 3 of thedrawin'gv nperture to capacity by rthe,use of. .a.suction bulbof1rela-f--"25 in"th 'ramebaselv lj," communicating. with tivclysmall size. theopeningZS, and 'in t'u'rn cnnunicating with Other objectscf my invention: will become ap- 1" an aperture 26 extendingv throvuglixthennipplre lg parent1` in the following-detailed description completes the""air `I`5asagewayl from .t thereof. l v 4o interierpf the `10u11@ 2v h' In the vaccompanyingdrawing,v in which. is. vv'lll' "f i v v shown'one-lolf the variouspossib-le embodimentsoi"` :En accordance' wit u y nvenzonl `Lepra my invention,vr Y ,4-5 w; vided'the'following sensitiv control rifeansflorefL Fig. 1.,.1'5 a side elevational 'viewg'partly in secef'iufierably located wholly within thebulb, anglfsor Yco tion, of a pipette and device therefor, constructed 45 Structfi'jliidaliagedfliftjw th in accordance with invention;;-.1': 'Y ffcollapsedorcompressed,Nair.I Y Fig. 2 is a fronteleyational view: exhausted throughthy tube "10,1

thereof;y f, Y L Si opening 30""i'n the" 'wal suctionbulb--1en lo,ved:er v n.. Fifictionally received Referring now in detailrto the drawing, I have and 2| is an air valve or`control tube 3| made of shown a pipette or tube I0 of the type customarily suitable flexible material, such as for example employed in laboratory work for collecting, trans- 55 rubber. When the bulb i2 is in its normal noni compressed position, the air tube 3| is open, the tube being preferably of such length that it will lie adjacent the wall of the bulb I2, as in Fig. 1.

I'n view of the above construction, the manner 'of use of my novel and improved pipette apparatus will now be described.

The portion l1 of the pipette device is hooked over the hand of the user with the thumb encircling the bulb l2 and with a nger overlying the opening 30. If it is desired to draw uid. into the tube I0, the bulb I2 is compressed against the frame Wall |5b. In view of the construction and arrangement of the angular nipple portion 20 after only a limited amount of compression of the bulb I2, the tube 3| Will be, clinched against the flattened end 2| to shut off the air passageway leading from the tube I0 to the interior of the said bulb I2. During this compressing operation the opening 30 is left uncovered so that the air within the bulb I2 may be expelled therethrough. After the bulb I2 has been fully compressed ,the opening 30 is covered by the thumb or finger and the compression of the bulb released. As soon as the said bulb I2 has been restored sufficiently to straighten out the kink in the air tube 3|, uid will be drawn into the tube I0 by the suction created within the bulb- I2, and held therein as long as the opening 30 remains covered, or by the closed air tube 3| if the tube is sealed by being clinched against the nipple portion 2|.

In View 0f the above described operation ofv my invention it is noted that if th'e tube |0 were of such size that a single complete compression and release of the bulb I2 would not ll the tube I0 to a sufficient height, the said tube III may be further filled by a second or third compression Y of the bulb- I2 with a minimum of loss of the uid 'already in the tube due to compression of the bulb. At the commencement of each such compression of the bulb, the air tube 3| is simultaneously and automatically actuated to close the air passageway, to retain the fluid already in the pipette. After the air passage is so sealed, the opening is uncovered,` and further compression expels the air from the bulb Opening 30 is now again covered, and as the compression of the bulb is released, the air. tube 3| straightens out, opening the passageway from the bulb to pipette II), so that additional fluid may be drawn up.

After a desired amount of fluid has been drawn into the tube I0 by the method above described,

sensitive dispensing control may bey exercised by sure on the clinched tube 3| will open the air passageway to permit gravity flow of the fluid from the tube Ill, the amount of flow ranging from a drop. to a stream, depending upon the amount of pressure of the tube 3| against the nipple portion 2|.

To facilitate the above described dispensing control action any suitable device may be provided on the outer surface of the bulb I2 to indicate where effective pressure is to be applied. In the drawing I have shown one such indicating device in the form of an -annular ridge'40.

It will thus be seen that there is provided a device in which the several objects Aof this invention are achieved, and which is well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

Having described my invention, I claim as new and desire to secure by Letters Patent:

1. In a laboratory apparatus of the class described, the combination of a tube, a suction bulb having a bottom aperture, means forinterconnecting said bulb with said tube whereby a suction may be created in said tube upon compressing and releasing said bulb, said last named means comprising a nipple member frictionally received in said bulb aperture and having a portion thereof projectinginto the hollow interior of said bulb, said member Vhaving an opening ytherethrough adapted to communicate with the hollow interior of said bulb and with said tube, and a iiexible tubular member within said bulb received on said projecting portion of said nipple to form a continuation of the air passageway from said tube to the interior of said bulb, said tubular member being adapted to be clinched up against said nipple portion upon compression of said bulb so that passage of air between said tube and said bulb may be shut olf or otherwise controlled.

` 2. In a laboratory apparatus of the class described, the combination according to claim 1 in which the suction bulb is provided with a second aperture adapted to be covered or uncovered by the thumb or nger of the user to obtain added iiow control.

3. In a laboratory apparatus of the class described, the combination according to claim 1 in which the said projecting portion of said nipple member terminates in a flattened end to facilitate the said clinching action of said flexible tubular member thereagainst.

4. In a laboratory apparatus of the class described, the combination according to claim 1 in which the said projecting portion o f said nipple member is angularly disposed in a direction t0- ward the wall of said bulb so that the free end of said flexible tubular member will lie adjacent the .said Wall of said bulb.

5. In a laboratory apparatus of the class described, the combination according to claim 1 in which the said projecting portion of said nipple member is angularly disposed in a direction toward the wall of said bulb so that the free end of said flexible tubular member will lie adjacent the said wall of said bulb, said angularly disposed portion of said nipple member terminating in a `iiattened'end to facilitate the clinching action of said flexible tubular member thereagainst,

6. In alaboratory apparatus of the class described, the combination according to claim 1 in .which the said projecting portion of said nipple member terminates in a flattened end to facilitate the said clinching action of said exible tubular member thereagainst, said suction bulb being provided with a second aperture adapted to be covered or uncovered by the thumb or linger of the user to obtain added flow control.

7. In a laboratory apparatus of the class described, the combination according to claim 1 in which the said projecting portion of said nipple member is angularly disposed in a direction toward the Wall of said bulb so that; the free end of said flexible tubular member will lie adjacent the said wall of said bulb, saidsuction bulb being provided with a second aperture to be covered or uncovered by the thumb or finger of the user to obtain added flow control.

8. In a laboratory apparatus of the class described, vthe combination according to claim l in which the said projecting portion of said nipple member is anglarly disposed in a direction toward the wall of said bulb so that the free ends of said flexible tubular member will lie adjacent the said wall of said bulb, said angularly disposed portion of said apertured member terminating in a attened end to facilitate the clinching action of said flexible tubular member thereagainst, said suction bulb being provided with a second aperture adapted to be covered or uncovered by the thumb or nger of the user to obtain added ow control.

9. In a laboratory apparatus of the class described, the combination of a tube, a suction bulb having a bottom aperture, means for interconnecting said bulb with said tube whereby a suction may be created in said tube upon compressing and releasing said bulb, said last named means comprising a frame having a base portion and a rigid wall upstanding therefrom adapted to serve as an abutment against which the said bulb is compressed, a nipple member mounted on said frame and having a portion thereof received in said bottom aperture of said bulb, said nipple member having a portion thereof projecting into the hollow interior of said bulb and a flexible tubular member within said bulb received on said projecting portion of said nipple, said flexible tubular member being adapted to be clinched up against said projecting nipple portion upon compression of said bulb.

10. In a laboratory apparatus of the class described, the combination according to claim 1 in which the said projecting portion of said apertured member terminates in a flattened end portion to facilitate the said clinching action of said flexible tubular member thereagainst, said suction bulb being provided with a second aperture adapted to be covered or uncovered by the thumb or finger of the user to obtain added ow control and means on the outer surface of said bulb to indicate where the said bulb is to be compressed to facilitate the said clinching action of said flexible tube.

11. In a laboratory apparatus of the class described, the combination according to claim 9 in which said suction bulb is provided with a second aperture adapted to be covered or uncovered by the thumb or nger of the user to obtain added flow control.

12. In a laboratory apparatus of the class described, the combination according to claim 9 in which said suction bulb is provided with a second aperture adapted to be covered or uncovered by the thumb or finger of the user to obtain added flow control and means on the outer surface of said bulb to indicate where the said bulb is to be compressed to facilitate the said clinching action of said flexible tube.

13. In a laboratory apparatus of the class described, the combination according to claim 9 in which the said frame is provided with a hook shaped holding member to facilitate the use of said apparatus.

14. In combination, a measuring tube, a suction bulb interconnected with said measuring tube, a flexible air controlling tube within said suction bulb and interconnected with said measuring tube,

said flexible air controlling tube being actuated by the side wall of said bulb as the bulb is compressed and released in producing the suction effect.

15. In combination, a measuring tube, a suction bulb interconnected with said measuring tube, a flexible air controlling tube within said suction bulb and interconnected with said measuring tube, one end of said air controlling tube being in contact with the inner walls of said bulb, whereby the air passageway through said controlling tube is automatically varied as the bulb is compressed and released in .producing the suction effect.

16. In combination, a measuring tube, a suction bulb, a nipple member interconnecting said measuring tube with said bulb, a exible air controlling tube disposed within said bulb and interconnected with said measuring tube, a portion of said flexible tube being disposed adjacent the wall of said bulb whereby the air passageway through said flexible tube is automatically varied as the bulb is compressed or released in producing the suction effect.

17. In combination, a measuring tube, a suction bulb, a nipple member interconnecting said measuring tube with said bulb, a flexible air controlling tube disposed within said bulb and interconnected with said measuring tube a portion of said flexible tube being disposed adjacent the wall of said bulb whereby the air passageway through said flexible tube is automatically varied as the bulb is compressed or released in producing the suction effect, and a frame associated with said nipple member, said frame having a rigid wall adapted to serve as an abutment against which the bulb is compressed.

18. In combination, a measuring tube, a suction bulb, a nipple member interconnecting said measuring tube with said bulb, a flexible air controlling tube disposed within said bulb and interconnected with Isaid measuring tube. a portion of said flexible tube being disposed adjacent the wall of said bulb whereby the air passageway through said flexible tube is automatically varied as the bulb is compressed or released in producing the suction effect, and a frame associated with said nipple member, said frame having a rigid wall adapted to serve as an abutment against which the bulb is compressed, said frame being profacilitate the use of said apparatus.

WADDY T. MATHIS.

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