US20030226749A1 - Limit switch - Google Patents
Limit switch Download PDFInfo
- Publication number
- US20030226749A1 US20030226749A1 US10/252,075 US25207502A US2003226749A1 US 20030226749 A1 US20030226749 A1 US 20030226749A1 US 25207502 A US25207502 A US 25207502A US 2003226749 A1 US2003226749 A1 US 2003226749A1
- Authority
- US
- United States
- Prior art keywords
- limit switch
- microswitch
- housing
- switch according
- actuator lever
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000004642 Polyimide Substances 0.000 claims abstract description 9
- 229920001721 polyimide Polymers 0.000 claims abstract description 9
- 230000007246 mechanism Effects 0.000 claims abstract description 7
- 238000005121 nitriding Methods 0.000 claims abstract description 5
- 229910001220 stainless steel Inorganic materials 0.000 claims abstract description 5
- 239000010935 stainless steel Substances 0.000 claims abstract description 5
- 239000012528 membrane Substances 0.000 claims description 11
- 230000006835 compression Effects 0.000 claims description 6
- 238000007906 compression Methods 0.000 claims description 6
- 239000002994 raw material Substances 0.000 claims description 2
- 238000005299 abrasion Methods 0.000 abstract description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 4
- 239000000945 filler Substances 0.000 abstract description 3
- 239000003921 oil Substances 0.000 abstract description 2
- 238000007789 sealing Methods 0.000 abstract description 2
- 229920002379 silicone rubber Polymers 0.000 abstract description 2
- 230000009471 action Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 230000002093 peripheral effect Effects 0.000 description 3
- 244000105017 Vicia sativa Species 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000005461 lubrication Methods 0.000 description 2
- 241000196324 Embryophyta Species 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000007767 bonding agent Substances 0.000 description 1
- 238000009435 building construction Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
- H01H13/02—Details
- H01H13/04—Cases; Covers
- H01H13/06—Dustproof, splashproof, drip-proof, waterproof or flameproof casings
- H01H13/063—Casings hermetically closed by a diaphragm through which passes an actuating member
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
- H01H13/02—Details
- H01H13/12—Movable parts; Contacts mounted thereon
- H01H13/14—Operating parts, e.g. push-button
- H01H13/18—Operating parts, e.g. push-button adapted for actuation at a limit or other predetermined position in the path of a body, the relative movement of switch and body being primarily for a purpose other than the actuation of the switch, e.g. door switch, limit switch, floor-levelling switch of a lift
- H01H13/186—Operating parts, e.g. push-button adapted for actuation at a limit or other predetermined position in the path of a body, the relative movement of switch and body being primarily for a purpose other than the actuation of the switch, e.g. door switch, limit switch, floor-levelling switch of a lift wherein the pushbutton is rectilinearly actuated by a lever pivoting on the housing of the switch
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/02—Bases, casings, or covers
- H01H9/0207—Adjustable mounting of casings
Definitions
- the present invention relates to a limit switch which limits or controls a movement, and, in particular, to a constitution of a non-contact type microswitch extensively used for industrial purpose which comprises water resistance, corrosion resistance and abrasion resistance.
- the limit switch is a switch to detect a position, a displacement, a movement, a passage and the like
- the microswitch is defined as a compact type switch designed and produced so that a switching operation to open and close an electrical current can be promptly and reliably performed with a small force.
- a conventional limit switch generally has an actuator of a lever type rotatably supported by a hinge, and when a free end of the actuator is pushed and moved by a cam and a dog of an operational mechanism, the movement thereof is transmitted to a slide pin, and by a snap action of a toggle mechanism and the like, a contact thereof is switched to OFF from ON or ON from OFF, so that a signal is outputted and an operation of a moving mechanism is detected.
- the object of the present invention is to provide a general type limit switch, which has abrasive resistance, corrosion resistance and water resistance, and is excellent in durability and, moreover, can function with a weak operating force.
- the limit switch according to the present invention is a flat box type housing as a basic model with a cavity concavely provided, and an outer surface of the housing comprises: two surfaces backward and forward in a thickness direction where mounting holes are piercingly provided at standard positions (a center distance between two places of mounting holes according to JIS C 4505 is: 25.4 mm) and which function as mounting surfaces; an upper surface which defines upper edges of these two surfaces and supports an actuator lever; and an under surface which defines under edges of these two surfaces and where the cavity is open, wherein a non-contact type microswitch is provided inside the cavity with upper and lower positions adjustable; and the actuator lever is supported on the upper surface by a cantilever plate spring; and a piston connecting the actuator lever and the microswitch is insertably mounted between both of them; and an annular concave portion circumference on the upper surface, where a piercing hole to fittingly mount the piston by being connected with the cavity is open, is sealed at the outer edge
- low small protrusions are convexly provided on at least two places of one side, and in the corresponding position of the other side, hole portions to fit the small protrusions are concavely provided.
- the plate spring is formed by polyimide
- the elastic membrane is formed by a disc bellows having an inclination along a flat conical surface with polyimide as a raw material.
- the actuator lever is formed by stainless steel (SUS304) and the surface thereof is subjected to nitriding processing.
- a top end of the actuator lever is extended to the housing side, and a square hole which controls a moving range is piercingly provided at a position facing the housing side so as to idly fit to a protrusion of the housing side.
- a compression coil is insertably mounted between the piston and a mounting board of the microswitch and supports a weight of the piston and an urging force by the elastic membrane.
- the mounting board of the microswitch is provided with an external thread on an outer periphery thereof and screwed into an internal thread provided on a piercing hole of the housing, and the mounting board of the microswitch is rotated so as to move a position relative to the actuator lever by a screw mechanism and a distance of an operating position by the actuator lever for a free position of the microswitch is made adjustable.
- FIG. 1 shows one embodiment of a limit switch according to the present invention.
- FIG. 1A is a plane view
- FIG. 1B is a cross sectional view cut along the line BB in FIG. 1A;
- FIG. 2 is a bottom view cut along the line II-II in FIG. 1B;
- FIG. 3 is a side view of a part by a cross-sectional view cut along the line III-III in FIG. 1B.
- FIG. 1 shows one embodiment of a limit switch 10 according to the invention
- FIG. 1A is a plane view
- FIG. 1B is a sectional view cut along the line B-B in FIG. 1A
- FIG. 2 is a bottom view cut along the line II-II in FIG. 1B
- FIG. 3 is a side view of a partial sectional view cut along the line III-III in FIG. 1B.
- a housing 12 of the limit switch 10 is an aluminum die cast molded article piercingly provided with mounting holes 16 , 17 which pass through two surfaces (surface parallel to the paper surface of FIG. 1B) 14 , 15 frontward and backward in a thickness direction at two places.
- a center distance between the mounting holes 16 , 17 is preferably set to 25.4 mm based on JIS C 4505 standard.
- Front surface 14 side opening of the mounting holes 16 , 17 is concavely provided with counter sinking holes 18 , 19 which sink heads of mounting bolts (not shown), and low small protrusions 20 , 21 loosely fittable to the counter sinking holes 18 , 19 are convexly provided on the periphery of the rear surface 15 of the mounting holes 16 , 17 .
- screw holes 23 a are carved at two places of a seat 23 provided at right side in the drawing of the upper surface 22 which defines the upper edges of the frontward and backward two surfaces 14 , 15
- bolt holes 24 b are piercingly provided at two places at positions aligned with the holes 23 a in the plate spring 25 of polyimide and a clamp 24 , respectively.
- a plate spring 25 is piercingly provided between the seat 23 and the clamp 24 , and s bolt 26 inserted into the bolt hole 24 b is screwed into the screw hole 23 a and clamped, and the plate spring 25 is compressed and fixed to the seat 23 by the clamp 24 .
- the plate spring 25 is detachable by this bolt connection so that, when dust is accumulated in a gap 22 a between the upper surface 22 and the plate spring 25 , it is possible to remove and clean the plate spring 25 . In the case where the plate spring 25 suffers an accidental damage from an external force, the plate spring 25 has advantages of being exchanged.
- Reference numeral 28 denotes an actuator lever, which is connected with a free end of the plate spring 25 by a rivet 29 .
- the actuator lever 28 is formed by a plate of stainless steel (SUS304) and is subjected to nitriding processing, and therefore, is excellent in corrosion resistance and abrasion resistance, and has little friction. Hence, there is a considerable degree of freedom in an operating direction by an operating member such as a dog, a cam and the like, and an exact vertical degree for an edge line of a sliding portion 28 b is not necessarily required. Since the actuator lever 28 is supported by the plate spring 25 having a cantilever constitution, an axis or a bearing that wears by receiving rotation does not exist. Accordingly, the actuator lever 28 does not require lubrication, and abrasion is not expedited by insertion of dust and rust.
- a free end 28 a of the actuator lever 28 is provided with a sliding portion 28 b with the dog and the cam not shown which receives operation and which is greatly bent upward in the drawing from an extension of the plate spring 25 at an angle of 45° and is further bent at the sliding portion 28 b at about 90°. Further, a top end portion 28 c is bent along the side 30 of the housing 21 and hangs down almost in parallel. On upper portion of the housing side 30 is concavely provided a notched portion 30 a , which movably stores the top end portion 28 c.
- the actuator lever top end portion 28 c is piercingly provided a square hole 32 (see FIG. 3), and the notched portion 30 a notches a position corresponding to almost a center of the square hole 32 and forms a control portion 30 b , which is idly fitted to the square hole 32 . Accordingly, the movement of the actuator lever 28 by a compelling force from the outside is controlled within a range where an inner edge of the square hole 32 abuts against the control portion 30 b . Further, the left and right peripheral walls 30 c remained on the outer periphery of the notched portion 30 a and a counter surface 30 d at the lower end of the top end portion 28 c control excessive movement and function as a safety stopper.
- a spherically formed apex face of a head 36 a of a piston 36 which transmits the movement of the actuator lever 28 to a non-contact type microswitch 34 , abuts.
- a base 36 b of the piston 36 is cylindrical, and on the upper end thereof, a seat 36 d having a diameter slightly larger than the base 36 b extends from an upper portion of a flange 36 c expanded in diameter, and a center hole of the head 36 a fits to a small diameter boss 36 e protruding from a center of the seat 36 d .
- a central portion of the disc bellows 38 of the elastic membrane formed by polyimide is insertingly mounted between the under surface of the head 36 a and the upper surface of the boss 36 d , and the joined surface thereof is completely sealed by polyimide.
- the disc bellows 38 has a coaxial wavelike convex-concave formed along a flat conical surface, and the same size diameter see-through hole as the boss 36 a passes through the center.
- a cavity 42 opened to an under surface 40 in the drawing at the side opposing to the upper surface 22 is shown in FIG. 2 as a bottom view.
- a piercing hole 44 having steps.
- a step portion 46 c having a diameter slightly larger than an outer shape of the flange 36 b which overhangs from the piston 36 , and the step portion 46 c controls a downward moving area of the flange 36 b and functions as a safety stopper for an excessive external force in a vertical direction.
- a reduced diameter cylindrical hole 46 d communicating with the cavity 42 from the step portion 46 c is carved an internal thread 48 , and in the cavity 42 , an opening expanded in diameter functions as a linear line guide portion 52 of a microswitch mounting board 50 .
- the microswitch mounting board 50 is cylindrical, and in the top end portion thereof is provided an external thread 54 which is screwed into an internal thread 48 of a lower portion of the cylindrical hole 46 d , and a base 56 is slidably fits to the linear line guide portion 52 .
- the under portion in the drawing of the base 56 is expanded in diameter and forms a microswitch mounting seat 58 , and is carved with a counter sinking hole 62 adapted to the outer shape of the ready-made non-contact type microswitch 34 , and the ready-made non-contact type microswitch is fixed inside the hole 62 by adequate means.
- a hole IC is utilized for the non-contact type microswitch 64 .
- a through hole 50 a In the center of the microswitch mounting board 50 is provided a through hole 50 a so that a base 36 b of the piston 36 is slidably fittingly mounted.
- the lower end portion of the through hole 50 a is a sliding portion 50 b which has little gap with the piston base 36 b , and in the upper portion other than this is provided an escape way expanded in diameter.
- a compression coil 64 Between the under surface of the flange 36 c of the piston and the upper surface of the external thread 54 of the microswitch mounting board is insertably mounted a compression coil 64 , which energizes the piston 36 upward so that the apex surface of the piston head 36 a is allowed to always abut against the under surface of the actuator lever 28 .
- the lower end in the drawing of the piston 36 abuts against a top end of an operating pin (actuator) 34 a , which is located at a free position of the ready-made microswitch 34 .
- an operating pin (actuator) 34 a which is located at a free position of the ready-made microswitch 34 . Since the microswitch 34 is a non-contact type, a return spring is weak, and in contrast to a contact which operates by a snap action of the conventional general industry limit switch, the microswitch 34 can be sufficiently functioned by an extremely slight operating force.
- a light emitting diode 68 may be mounted as an operating indicator light.
- the microswitch can be handled as a sensor also for an extremely sensitive positioning, a displacement, a movement or a passage with a sense for usual machine parts, and moreover, the same operating sensitivity as the microswitch is guaranteed.
- the convex portion and the concave portion which are provided on the mounting surface and fit to each other, mutual precise positioning can be easily performed in using the lamination layers of a plurality of microswitches.
- the non-contact type microswitch is installed with the upper and lower positions adjustable, an appropriate operating position can be set. Furthermore, the actuator lever is supported by a cantilever plate spring, and the piston, which transmits the movement of the actuator lever to the non-contact type microswitch, is supported by a bellows-shaped elastic membrane. Since there exist no frictional portions, lubrication is not required, and since there exist no frictional components, durability is improved.
- the connecting portion between the bellows-shaped piston and the housing is sealed air tight and the non-contact type microswitch is sealed inside the cavity of the housing by the filler, the electrical contact is completely isolated from the external world, and the limit switch becomes completely a waterproof and dustproof type, so that use in water and oil and in bad surroundings where a lot of dusts abound is possible.
- the actuator lever is formed by stainless steel (SUS304), and the surface thereof is subjected to nitriding processing, and the plate spring and the bellows-shaped elastic membrane are formed by polyimide, the actuator lever is excellent in erosion resistance and abrasion resistance.
- a moving range of the actuator lever is controlled by the protrusion of the housing side which idly fits inside the square hole of the top end, and moreover, the notched portion of the housing which stores the top end of the actuator lever can be allowed to function as a safety stopper.
- the non-contact type microswitch can be prevented from being affected by unreasonable external force.
- the compression coil spring insertably mounted between the piston and the microswitch mounting board supports the urging force by the tare of the piston and the wavelike elastic membrane, regardless of a mounting posture of the limit switch, a stable constant operating position can be secured, and the microswitch mounting board can precisely set the operating position for the free position of the microswitch by the actuator by a slight adjustment by a screw mechanism.
Landscapes
- Push-Button Switches (AREA)
- Rotary Switch, Piano Key Switch, And Lever Switch (AREA)
- Switches That Are Operated By Magnetic Or Electric Fields (AREA)
Abstract
A limit switch sealing anon-contact type microswitch has a stainless steel actuator lever subjected to nitriding processing which is cantilever supported on a housing upper portion by a plate spring made of polyimide. A non-contact type microswitch stored inside a housing cavity is slightly adjusted for upward and downward positions by a screw mechanism, and after that, is sealed inside the cavity by the filler such as silicon rubber and the like. A piston which transmits the movement of the actuator lever to the microswitch is supported air tight by the housing at the center of a flat conical bellows, and the limit switch including a return coil spring is highly sensitive, and is excellent in water resistance, oil resistance, abrasion resistance and durability.
Description
- 1. Field of the Invention
- The present invention relates to a limit switch which limits or controls a movement, and, in particular, to a constitution of a non-contact type microswitch extensively used for industrial purpose which comprises water resistance, corrosion resistance and abrasion resistance. It is to be noted that the limit switch is a switch to detect a position, a displacement, a movement, a passage and the like, and the microswitch is defined as a compact type switch designed and produced so that a switching operation to open and close an electrical current can be promptly and reliably performed with a small force.
- 2. Description of the Related Art
- A conventional limit switch generally has an actuator of a lever type rotatably supported by a hinge, and when a free end of the actuator is pushed and moved by a cam and a dog of an operational mechanism, the movement thereof is transmitted to a slide pin, and by a snap action of a toggle mechanism and the like, a contact thereof is switched to OFF from ON or ON from OFF, so that a signal is outputted and an operation of a moving mechanism is detected.
- However, since an urging force which actuates the limit switch receives resistance due to a reaction accompanied with a snap action of the contact by moving the actuator lever, an urging force large enough to overcome the resistance is required. Therefore, in order to avoid an influence, which exerts a counteraction on the function, it is better that an operating force of the limit switch is as weak as possible. Further, in bad surroundings where the limit switch is used not only for industrial machines, but also for field equipment of civil engineering, building construction and the like, abrasion due to accumulation of dust and repeated operations is unavoidable for a spindle of the hinge which supports the lever to function as the actuator. A sealed microswitch of JIS C 4508 is a large type, and is difficult to use conveniently for the places, which require a compact construction.
- Therefore, the object of the present invention is to provide a general type limit switch, which has abrasive resistance, corrosion resistance and water resistance, and is excellent in durability and, moreover, can function with a weak operating force.
- In order to achieve the above-described object, the limit switch according to the present invention is a flat box type housing as a basic model with a cavity concavely provided, and an outer surface of the housing comprises: two surfaces backward and forward in a thickness direction where mounting holes are piercingly provided at standard positions (a center distance between two places of mounting holes according to JIS C 4505 is: 25.4 mm) and which function as mounting surfaces; an upper surface which defines upper edges of these two surfaces and supports an actuator lever; and an under surface which defines under edges of these two surfaces and where the cavity is open, wherein a non-contact type microswitch is provided inside the cavity with upper and lower positions adjustable; and the actuator lever is supported on the upper surface by a cantilever plate spring; and a piston connecting the actuator lever and the microswitch is insertably mounted between both of them; and an annular concave portion circumference on the upper surface, where a piercing hole to fittingly mount the piston by being connected with the cavity is open, is sealed at the outer edge of the elastic membrane which supports the piston by seal-connecting the piston with the center potion; and, moreover, the cavity which stores the microswitch is filled with a sealing agent.
- In two surfaces which function as the mounting surfaces, low small protrusions are convexly provided on at least two places of one side, and in the corresponding position of the other side, hole portions to fit the small protrusions are concavely provided. Further, the plate spring is formed by polyimide, and the elastic membrane is formed by a disc bellows having an inclination along a flat conical surface with polyimide as a raw material. Further, the actuator lever is formed by stainless steel (SUS304) and the surface thereof is subjected to nitriding processing. In addition, a top end of the actuator lever is extended to the housing side, and a square hole which controls a moving range is piercingly provided at a position facing the housing side so as to idly fit to a protrusion of the housing side. On the other hand, a compression coil is insertably mounted between the piston and a mounting board of the microswitch and supports a weight of the piston and an urging force by the elastic membrane. Further, the mounting board of the microswitch is provided with an external thread on an outer periphery thereof and screwed into an internal thread provided on a piercing hole of the housing, and the mounting board of the microswitch is rotated so as to move a position relative to the actuator lever by a screw mechanism and a distance of an operating position by the actuator lever for a free position of the microswitch is made adjustable.
- FIG. 1 shows one embodiment of a limit switch according to the present invention. FIG. 1A is a plane view, and FIG. 1B is a cross sectional view cut along the line BB in FIG. 1A;
- FIG. 2 is a bottom view cut along the line II-II in FIG. 1B; and
- FIG. 3 is a side view of a part by a cross-sectional view cut along the line III-III in FIG. 1B.
- Hereinafter, an embodiment of a limit switch according to the present invention will be described based on the drawings. FIG. 1 shows one embodiment of a
limit switch 10 according to the invention, and FIG. 1A is a plane view and FIG. 1B is a sectional view cut along the line B-B in FIG. 1A. Further, FIG. 2 is a bottom view cut along the line II-II in FIG. 1B, and further FIG. 3 is a side view of a partial sectional view cut along the line III-III in FIG. 1B. - A
housing 12 of thelimit switch 10 is an aluminum die cast molded article piercingly provided withmounting holes mounting holes Front surface 14 side opening of themounting holes counter sinking holes small protrusions counter sinking holes rear surface 15 of themounting holes - Hence, for example, by providing a concave portion, to which the
small protrusions - In FIG. 1B,
screw holes 23 a are carved at two places of aseat 23 provided at right side in the drawing of theupper surface 22 which defines the upper edges of the frontward and backward twosurfaces bolt holes 24 b are piercingly provided at two places at positions aligned with theholes 23 a in theplate spring 25 of polyimide and aclamp 24, respectively. Aplate spring 25 is piercingly provided between theseat 23 and theclamp 24, and sbolt 26 inserted into thebolt hole 24 b is screwed into thescrew hole 23 a and clamped, and theplate spring 25 is compressed and fixed to theseat 23 by theclamp 24. In theclamp 24 is concavely provided acounter sinking hole 24 a which sinks ahead 26 a of the bold 26. Theplate spring 25 is detachable by this bolt connection so that, when dust is accumulated in agap 22 a between theupper surface 22 and theplate spring 25, it is possible to remove and clean theplate spring 25. In the case where theplate spring 25 suffers an accidental damage from an external force, theplate spring 25 has advantages of being exchanged. -
Reference numeral 28 denotes an actuator lever, which is connected with a free end of theplate spring 25 by arivet 29. Theactuator lever 28 is formed by a plate of stainless steel (SUS304) and is subjected to nitriding processing, and therefore, is excellent in corrosion resistance and abrasion resistance, and has little friction. Hence, there is a considerable degree of freedom in an operating direction by an operating member such as a dog, a cam and the like, and an exact vertical degree for an edge line of a slidingportion 28 b is not necessarily required. Since theactuator lever 28 is supported by theplate spring 25 having a cantilever constitution, an axis or a bearing that wears by receiving rotation does not exist. Accordingly, theactuator lever 28 does not require lubrication, and abrasion is not expedited by insertion of dust and rust. - A
free end 28 a of theactuator lever 28 is provided with a slidingportion 28 b with the dog and the cam not shown which receives operation and which is greatly bent upward in the drawing from an extension of theplate spring 25 at an angle of 45° and is further bent at the slidingportion 28 b at about 90°. Further, atop end portion 28 c is bent along theside 30 of thehousing 21 and hangs down almost in parallel. On upper portion of thehousing side 30 is concavely provided a notchedportion 30 a, which movably stores thetop end portion 28 c. - On the other hand, in the actuator lever
top end portion 28 c is piercingly provided a square hole 32 (see FIG. 3), and thenotched portion 30 a notches a position corresponding to almost a center of thesquare hole 32 and forms acontrol portion 30 b, which is idly fitted to thesquare hole 32. Accordingly, the movement of the actuator lever 28 by a compelling force from the outside is controlled within a range where an inner edge of thesquare hole 32 abuts against thecontrol portion 30 b. Further, the left and rightperipheral walls 30 c remained on the outer periphery of thenotched portion 30 a and acounter surface 30 d at the lower end of thetop end portion 28 c control excessive movement and function as a safety stopper. - Against the vicinity of the connecting portion with the
plate spring 25 of theactuator lever 28, a spherically formed apex face of ahead 36 a of apiston 36, which transmits the movement of theactuator lever 28 to anon-contact type microswitch 34, abuts. Abase 36 b of thepiston 36 is cylindrical, and on the upper end thereof, aseat 36 d having a diameter slightly larger than thebase 36 b extends from an upper portion of aflange 36 c expanded in diameter, and a center hole of thehead 36 a fits to asmall diameter boss 36 e protruding from a center of theseat 36 d. A central portion of thedisc bellows 38 of the elastic membrane formed by polyimide is insertingly mounted between the under surface of thehead 36 a and the upper surface of theboss 36 d, and the joined surface thereof is completely sealed by polyimide. The disc bellows 38 has a coaxial wavelike convex-concave formed along a flat conical surface, and the same size diameter see-through hole as theboss 36 a passes through the center. - As shown in FIG. 1B, in the
housing 12 is formed acavity 42 opened to an undersurface 40 in the drawing at the side opposing to theupper surface 22, and is shown in FIG. 2 as a bottom view. From theupper surface 22 to thecavity 42 is passed a piercinghole 44 having steps. On theupper surface 22 to which the piercinghole 44 is opened is formed an inclined plane annularconcave portion 46 expanded upward in diameter, where aperipheral wall 46 a expands upward, and a circumference where aperipheral wall 46 a contacts a undersurface 46 b is allowed to abut against an outer periphery of the disc bellows 38 so as to be sealed by s bonding agent. In theunder surface 46 is concavely provided astep portion 46 c having a diameter slightly larger than an outer shape of theflange 36 b which overhangs from thepiston 36, and thestep portion 46 c controls a downward moving area of theflange 36 b and functions as a safety stopper for an excessive external force in a vertical direction. - In the under portion of a reduced diameter
cylindrical hole 46 d communicating with thecavity 42 from thestep portion 46 c is carved aninternal thread 48, and in thecavity 42, an opening expanded in diameter functions as a linearline guide portion 52 of amicroswitch mounting board 50. Themicroswitch mounting board 50 is cylindrical, and in the top end portion thereof is provided anexternal thread 54 which is screwed into aninternal thread 48 of a lower portion of thecylindrical hole 46 d, and abase 56 is slidably fits to the linearline guide portion 52. The under portion in the drawing of thebase 56 is expanded in diameter and forms amicroswitch mounting seat 58, and is carved with acounter sinking hole 62 adapted to the outer shape of the ready-madenon-contact type microswitch 34, and the ready-made non-contact type microswitch is fixed inside thehole 62 by adequate means. Note that a hole IC is utilized for thenon-contact type microswitch 64. - In the center of the
microswitch mounting board 50 is provided a throughhole 50 a so that a base 36 b of thepiston 36 is slidably fittingly mounted. The lower end portion of the throughhole 50 a is a slidingportion 50 b which has little gap with thepiston base 36 b, and in the upper portion other than this is provided an escape way expanded in diameter. Between the under surface of theflange 36 c of the piston and the upper surface of theexternal thread 54 of the microswitch mounting board is insertably mounted acompression coil 64, which energizes thepiston 36 upward so that the apex surface of thepiston head 36 a is allowed to always abut against the under surface of theactuator lever 28. On the other hand, the lower end in the drawing of thepiston 36 abuts against a top end of an operating pin (actuator) 34 a, which is located at a free position of the ready-mademicroswitch 34. Since themicroswitch 34 is a non-contact type, a return spring is weak, and in contrast to a contact which operates by a snap action of the conventional general industry limit switch, themicroswitch 34 can be sufficiently functioned by an extremely slight operating force. - In order that the operating position of the contact is not largely affected by tares of the
actuator lever 28 and thepiston 36 depending on a mounting direction of thelimit switch 10, elasticity of theplate spring 25, the disc bellows 38 and thecompression coil spring 64 is comprehensively set. By rotation of themicroswitch mounting board 50, thepiston 36 and thecompression coil spring 64 moves together upward and downward, and can adjust a distance of an operating position (shown by two-dot chain line) relative to the free position of theactuator lever 28 shown in FIG. 1A by a solid line. After performing a prescribed operating position adjustment in a plant and drawing out a cable (not shown) wired in thenon-contact type microswitch 34 from adistribution port 66 of thehousing 12, thecavity 42 is sealed by silicon rubber or an epoxy filler. - As described above, while one embodiment of the limit switch according to the present invention is described based on the drawings, the invention is not limited to the illustrated embodiment, and it is expected that a variety of changes and modifications with respect to the details and alternation such as reconstitution of parts and the like can be performed in a range not deviating from the constituent features of the present invention. For example, as an operating indicator light, a
light emitting diode 68 may be mounted. - As evidenced by the above-described explanation, according to the limit switch according to the present invention, since a micro-shaped non-contact type microswitch requiring a delicate attention in handling is sealed into a basic model limit switch, the microswitch can be handled as a sensor also for an extremely sensitive positioning, a displacement, a movement or a passage with a sense for usual machine parts, and moreover, the same operating sensitivity as the microswitch is guaranteed. By the convex portion and the concave portion which are provided on the mounting surface and fit to each other, mutual precise positioning can be easily performed in using the lamination layers of a plurality of microswitches.
- Further, since the non-contact type microswitch is installed with the upper and lower positions adjustable, an appropriate operating position can be set. Furthermore, the actuator lever is supported by a cantilever plate spring, and the piston, which transmits the movement of the actuator lever to the non-contact type microswitch, is supported by a bellows-shaped elastic membrane. Since there exist no frictional portions, lubrication is not required, and since there exist no frictional components, durability is improved. Further, since the connecting portion between the bellows-shaped piston and the housing is sealed air tight and the non-contact type microswitch is sealed inside the cavity of the housing by the filler, the electrical contact is completely isolated from the external world, and the limit switch becomes completely a waterproof and dustproof type, so that use in water and oil and in bad surroundings where a lot of dusts abound is possible.
- Further, since the actuator lever is formed by stainless steel (SUS304), and the surface thereof is subjected to nitriding processing, and the plate spring and the bellows-shaped elastic membrane are formed by polyimide, the actuator lever is excellent in erosion resistance and abrasion resistance. In addition, a moving range of the actuator lever is controlled by the protrusion of the housing side which idly fits inside the square hole of the top end, and moreover, the notched portion of the housing which stores the top end of the actuator lever can be allowed to function as a safety stopper. Further, for the downward movement in an excessive vertical direction, which acts on the actuator lever, since the lower step of the disc bellows elastic membrane prevents the downward movement of the piston flange, the non-contact type microswitch can be prevented from being affected by unreasonable external force.
- On the other hand, since the compression coil spring insertably mounted between the piston and the microswitch mounting board supports the urging force by the tare of the piston and the wavelike elastic membrane, regardless of a mounting posture of the limit switch, a stable constant operating position can be secured, and the microswitch mounting board can precisely set the operating position for the free position of the microswitch by the actuator by a slight adjustment by a screw mechanism.
Claims (9)
1. A limit switch, comprising:
a box type housing:
a non-contact type microswitch provided inside a cavity of the housing;
an actuator lever supported on an upper surface of the housing by a cantilever plate spring;
a piston provided between the actuator and microswitch connecting both of them; and
an elastic membrane to seal and combine the piston.
2. The limit switch according to claim 1 , wherein, on two surfaces functioning as mounting surfaces of the housing, low small protrusions are convexly provided at least on two places of one surface, and hole portions to fit to the small protrusions are concavely provided on corresponding positions of the other surface.
3. The limit switch according to claim 1 , wherein the plate spring is formed by polyimide.
4. The limit switch according to claim 1 , wherein the elastic membrane is a disc bellows having an inclination along a flat conical surface and is formed by polyimide as a raw material.
5. The limit switch according to claim 1 , wherein the actuator is formed by stainless steel and the surface thereof is subjected to nitriding processing.
6. The limit switch according to claim 1 , wherein a top end of the actuator lever is extended to the housing side, and a square hole which controls a moving range is piercingly provided at a position facing the housing side so as to idly fit to a protrusion of the housing side.
7. The limit switch according to claim 1 , wherein a compression coil spring is insertably mounted between the piston and a mounting board of the microswitch and supports a weight of the piston and an urging force by the elastic membrane.
8. The limit switch according to clam 7, wherein the mounting board of the microswitch is provided with an external thread on an outer periphery thereof and screwed into an internal thread provided on a piercing hole of the housing.
9. The limit switch according to claim 8 , wherein the mounting board of the microswitch is rotated so as to move a position relative to the actuator lever by a screw mechanism and a distance of an operating position by the actuator lever for a free position of the microswitch is made adjustable.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2002170001A JP3722287B2 (en) | 2002-06-11 | 2002-06-11 | Limit switch |
JP2002-17001 | 2002-06-11 | ||
JP2002-170001 | 2002-06-11 |
Publications (2)
Publication Number | Publication Date |
---|---|
US6653583B1 US6653583B1 (en) | 2003-11-25 |
US20030226749A1 true US20030226749A1 (en) | 2003-12-11 |
Family
ID=29706847
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/252,075 Expired - Fee Related US6653583B1 (en) | 2002-06-11 | 2002-09-20 | Limit switch |
Country Status (4)
Country | Link |
---|---|
US (1) | US6653583B1 (en) |
JP (1) | JP3722287B2 (en) |
CN (1) | CN1236460C (en) |
DE (1) | DE10250908B4 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1734548A2 (en) * | 2005-06-13 | 2006-12-20 | Alps Electric Co., Ltd. | Switch device |
EP2001035A2 (en) * | 2007-06-08 | 2008-12-10 | Norman Victor Wheat | Economical force sensitive switch |
EP2413342A1 (en) * | 2010-07-31 | 2012-02-01 | Kissling Elektrotechnik GmbH | Electronic tappet switch |
CN104051165A (en) * | 2014-06-27 | 2014-09-17 | 陕西群力电工有限责任公司 | Full-sealed precise microswitch |
US9899084B2 (en) | 2014-07-24 | 2018-02-20 | Huawei Technologies Co., Ltd. | Data storage method and phase change memory |
US10083749B2 (en) | 2014-07-24 | 2018-09-25 | Huawei Technologies Co., Ltd | Data storage method and phase change memory |
Families Citing this family (10)
Publication number | Priority date | Publication date | Assignee | Title |
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US7271356B2 (en) * | 2001-10-31 | 2007-09-18 | Truett Brett B | Hybrid limit switch |
US20050231318A1 (en) * | 2004-04-15 | 2005-10-20 | James Bullington | Trip-free limit switch and reset mechanism |
US7367584B2 (en) * | 2004-04-19 | 2008-05-06 | Automotive Systems Laboratory, Inc. | Gas generating system |
CN102751115A (en) * | 2011-04-22 | 2012-10-24 | 鸿富锦精密工业(深圳)有限公司 | Early warning switch and box body using same |
CN102305762B (en) * | 2011-05-12 | 2013-07-31 | 苏州市诺弗电器有限公司 | Joystick |
JP2013000986A (en) * | 2011-06-17 | 2013-01-07 | Brother Industries Ltd | Inkjet printer |
US10314283B2 (en) * | 2016-06-03 | 2019-06-11 | Hog Slat, Inc. | Curtain machine having sealed control enclosure |
CN108284795B (en) * | 2017-01-10 | 2020-08-07 | 比亚迪股份有限公司 | Lifting mechanism and vehicle with same |
CN108155036A (en) * | 2017-12-22 | 2018-06-12 | 贵州航天电器股份有限公司 | A kind of force transmission mechanism for miniature airtight sealing switch |
CN114336400B (en) * | 2021-12-30 | 2024-08-02 | 刘健 | Auxiliary boosting hammer mechanism for operating rod of electric power system |
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US3898405A (en) * | 1974-01-11 | 1975-08-05 | Ernesto Juan Weber | Diaphragm pressure switch with balance plate and adjustable springs |
US4454397A (en) * | 1982-06-23 | 1984-06-12 | Wico Corporation | Push button switch assembly |
DE3710645A1 (en) * | 1987-03-31 | 1988-10-20 | Delaval Turbine Gmbh | PRESSURE SWITCH |
DE3842960A1 (en) * | 1988-12-21 | 1990-06-28 | Barlian Reinhold | METHOD FOR CAPSULATING A SWITCH AND SWITCH DEVICE THEREFORE PRODUCED |
DE9013310U1 (en) * | 1990-09-20 | 1990-11-29 | Burgess GmbH, 2900 Oldenburg | Electrical switch, especially miniature switch, with an operating lever |
US5140113A (en) * | 1991-05-22 | 1992-08-18 | United Electric Controls Company | Differential pressure control switch with a pivoting actuating lever and a biasing spring sealed in a housing |
DE4244706C2 (en) * | 1992-10-05 | 1994-08-11 | Barlian Reinhold | Switching device |
JP2002510423A (en) * | 1997-04-09 | 2002-04-02 | マルクアルト ゲーエムベーハー | Electric switch |
-
2002
- 2002-06-11 JP JP2002170001A patent/JP3722287B2/en not_active Expired - Fee Related
- 2002-09-20 US US10/252,075 patent/US6653583B1/en not_active Expired - Fee Related
- 2002-09-29 CN CN02144002.6A patent/CN1236460C/en not_active Expired - Fee Related
- 2002-10-31 DE DE10250908A patent/DE10250908B4/en not_active Expired - Fee Related
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1734548A2 (en) * | 2005-06-13 | 2006-12-20 | Alps Electric Co., Ltd. | Switch device |
EP1734548A3 (en) * | 2005-06-13 | 2007-01-17 | Alps Electric Co., Ltd. | Switch device |
EP2001035A2 (en) * | 2007-06-08 | 2008-12-10 | Norman Victor Wheat | Economical force sensitive switch |
EP2001035A3 (en) * | 2007-06-08 | 2009-08-26 | Norman Victor Wheat | Economical force sensitive switch |
EP2413342A1 (en) * | 2010-07-31 | 2012-02-01 | Kissling Elektrotechnik GmbH | Electronic tappet switch |
US8350649B2 (en) | 2010-07-31 | 2013-01-08 | Kissling Electrotechnik GmbH | Electronic plunger switch |
CN104051165A (en) * | 2014-06-27 | 2014-09-17 | 陕西群力电工有限责任公司 | Full-sealed precise microswitch |
US9899084B2 (en) | 2014-07-24 | 2018-02-20 | Huawei Technologies Co., Ltd. | Data storage method and phase change memory |
US10083749B2 (en) | 2014-07-24 | 2018-09-25 | Huawei Technologies Co., Ltd | Data storage method and phase change memory |
Also Published As
Publication number | Publication date |
---|---|
DE10250908A1 (en) | 2004-01-08 |
JP2004014450A (en) | 2004-01-15 |
US6653583B1 (en) | 2003-11-25 |
JP3722287B2 (en) | 2005-11-30 |
CN1466159A (en) | 2004-01-07 |
DE10250908B4 (en) | 2005-08-04 |
CN1236460C (en) | 2006-01-11 |
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