US2347874A - Electric switch - Google Patents

Description

Ma" 2, 1944 A. A. BLUEMLE y 2,347,874

ELECTRIC; SWITCH Filed Sept. '7, 1942 fyi'- v ,Y 45 INVEN-roR Patented May 2, 1 944 man STATES PATENT oFFlcE ELECTRIC SWITCH mold a. mucmlc, Anderson, nid., goor io General Motors Corporation, Detroit, Mich., a corporation of Delaware Application September 7. 1942, Serial N0. 457,552

i calms. (ci. coo-7i) This invention relates to manually closed. spring opened electric switches and it aims to provide a switch having means for maintaining adequate pressure between the contacts of the switch although the force applied to the operating handle of the switch may vary within certain limits, and having means for obtaining a quick break of an electrical circuit regardless of the rate of return of the handle to the open position of the switch.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accom panying drawing wherein a preferred embodihandle 30'and rod 26 toward the right and holds the movable contact l2 away from the ilxed contacts Il and the stop ange 2'2 against the bearing 2|.

The sleeve 2U is provided with grooves it separated by a ridge it. Groove 43 normally receives balls d6 located in pockets lil closed by plugs d8 and urged into said groove by springs is maintained bythe plugs 48 in an initial state of compression. Y

Fig. l shows the switch in the OFF position. `When moving the handle t@ to the left to close the switch as shown in Fig. 2, the sleeve 29 engages the sleeve 2t which transmits motion to the contact i2 through the spring 23 to cause said contact to engage contacts Il with yielding pressure. Rivet it should loosely t the sleeve 20 so that the pressure between'the xed and movable contacts will be substantially equal.

ment of the invention is clearly shown. Fig. 2 shows that the spring 23 has been com- In the drawing: pressed further than in Fig. 1 thereby increasing Figs. l, 2 and 3 are longitudinal sectional views the contact pressure. Maintenance of the enof the switch showing its movable contact in f sagement of the contacts is effected by the spring diil'erent positions. 69 which act through the balls do, then received The switch comprises a housing is enclosing by groove 4t. in such manner as to apply force ilxed contacts ii and a movable contact l2.' against the right inclined Side 0f ridge 45 thus Housing i@ is closed by a te plate it sup tourge thevsleeve 2li toward the left. When the porting terminal screws it carrying the con.. contact i 2 is at im in Fig. l, the ridge is at 45a tacts i and attached to the housing i@ by screws and the balls are at da. As the sleeve 20 conls. ontacc i2 is attached to c metal tubular 25 tinucs its movement toward the left. the peak rivet ls and is insulated therefrom by washer of the ridge i5 passes between the balls 46, thereil, bushing i3 and plate i9 all of insulating maby causing the springs 49 to become eiective to terial. Rivet is is mounted on s sleeve 2c slidmaintain the sleeve 2@ in position for causing ably supported by c, bearing 2i provided by the spring 23 to maintain the contact l2 in enhousine it and having a stop ange s2 engagc- 30 sagement with contacts ii. Handle 3B may move able with thc left end of said bearing. A Sp1-mg right a substantial amount from the position 23, interposed between aange 22 and plate as, shown ln Fig. 2 before the sleeve 20 is caused to urges the rivet is against a washer as retained mcvcrisht. Therefore casing of pressure on the by a flange 25 on the 1ere end 0f sleeve 2o, handle 3@ will not eiectively change the pressure A rod 26 is slidable through the sleeve 2l! and 35 between Switch Contacts. In fact handle 30 has a flange 2i engaging the' aange 2e. The might bc moved to the richt by Spring stl cumrighc end of rod is carries c aange 2s located cientlv to take up the clearance between danse in a recess in a sleeve ,-29 and conned therein 2l and rod 2t and iiange 25 of sleeve 2l) and to by a handle 3o attached to the sleeve 29 by a cause thereafter some movement of the sleeve screw 3i engaging a groove 32 in the sleeve 29. 40 2B toward the right, but themovable contact l2 Handle 30 has a tubular part 33 telescoping with, Will remain in engagement With Xed COIlaCfS Il a tubular part 34 provided by housing i0. Part as long as balls is engage the right Side 0f ridge Sltis threaded to receive nuts and 3l with 55. This feature is advantageous fOr example, a washer interposed. Space 3e receives an inwhen the switch is used to control the circuit strumcntal page1 (not shown) having a hole 45 of an electric starting motor. When the switch through which the pari se extends. Nuts 35 and has been closed, it is not necessary to exert upon Si are tightened against the panel to secure the the handle 30 that force required to close the switch thereto. A spring 4B, located between switch. Engine starting may require several secthe sleeve 29 and a washer 4l engaging a shoul- OndS and the Cal' drivel iS 42113i? t0 Ease-up .the der sz provided b y the housing lo, urges the pressure upon the switch handle unconsciously;

but this will not cause the switch to open.

To open the switch, the handle 30 is released to permit spring 4c to expand and to move rod 26 right to separate sleeve 29 from sleeve 20 and 43 and 65 to cause ilange 21 to engage flange 25. Then the sleeve 20 will' start to move right. but the contact I2 will still remain in engagement with contact I I. This engagement will be maintained until ridge I5 arrives substantially at 6b in Fig. 3, whereupon spring 49 will cause the balls 46 to urge the sleeve 20 right ahead of movement of rod 26 thereby causing the sleeve 20 to move toward the sleeve 29 and the washer 24 to engage the rivet i6 and thus cause the sleeve to separate the contact I2 from the contacts il although the. sleeve 29 has moved no further to the right than the position shown in Fig. 3. In this way, the breaking of the circuit .by the switch is caused to take place rapidly independently of the rate oi' movement of handle 30 to the right. Therefore it is impossible to cause undue arcing at the switch contacts by causing the handle 30 to move to the right relatively slowly.

I claim:

1. In an electric switch the combination comprising stationary contacts; a movable contact; a sleeve having cam means and supporting the movable contact; a shaft slidably supported by operating with the cam means to prevent retrothe sleeve; releasable holding means cooperating with the cam means; a plunger;'spring means resisting movement of the plunger in one direction; a second spring biasing the movable contact toward the stationary contacts; means to actuate the plunger in one direction, said plunger when actuated in said one direction is capable of moving a certain distance relative to the sleeve before engaging the sleeve to move same and the movable contact into engagement with the stationary bontacts, said sleeve gradually compressing the second spring after the movable contact engages the stationary contacts to increase the contact pressure between the contacts, and said releasable holding means cooperating with the cam means to hold the sleeve against retrograde movement on slight retrograde movement of the plunger so as to maintain the full pressure between the contacts up to the time the plunger moves the sleeve a certain distance in the reverse direction when the holding means moves the sleeve relative to the movement of the plunger in its reverse direction to separate the movable contact from the stationary contacts with a snap action.

2. A switch comprising in combination; a housing; a closure for the housing and carrying stationary contacts; an inner sleeve slidably supported within the housing; an outer sleeve slidably supported by the housing and manually operated for moving the inner sleeve in one direction; a rod fixed to the outer sleeve and extending through the inner sleeve; lateral means carried by the rod for holding the inner sleeve in assembled relation with the rod and also for moving the sleeve in the opposite direction; a movable contact slidably and yleldingly supported on the inner sleeve; resilient means acting on the outer sleeve and causing the lateral means of the rod to engage and shift the inner sleeve to a certain position to hold normally the movable contact separated from the stationary contacts; and coacting means carried by the housing and the inner sleeve operating to increase the contact pressure between the contacts after engagement thereof, and said coacting means also operating to r'nove the inner sleeve relative to the rod to snap the movable contact out of engagement from the stationary contacts after predetermined movement of the outer sleeve toward its normal position.

3. A switch comprising in combination; a housing; a closure carrying terminals for the housing; a pair oi' spaced sleeves slidably and separately supported by the housing; a rod fixed at one end to the first sleeve and slidably 'supported by the 5 second sleeve, said rod having provisions at the l0 for bridging the terminals; a light spring for urging the contact in one direction; a heavy spring acting on the rst sleeve to move the sleeves so that the contact is in anon-bridging position; cam means provided by the second 15 sleeve; spring urged balls carried by the housing and engageable with the cam means; means for actuating the first sleeve and the rod in one direction against the action of the heavy spring; means carried by the rod for moving the second 20 sleeve after predetermined movement of the rod for moving the second sleeve and the contact in the same direction to bridge the terminals and also to compress the light spring whereby full pressure contact is obtained, said ball means cograde movement of thc sleeve upon slight return movement of thel rod and also to move the sleeve with a snap action relative to the rod to separate the contact before the rod reaches its normal home position.

4. A switch comprising in combination; a housing; stationary contacts carried by the housing; a reciprocable sleeve supported by the housing; a reciprocable contact means mounted on the sleeve; spring means for urging the contact means against a stop provided by the sleeve; a reciprocable actuator slidably supported by the sleeve and having shoulders on opposite ends of sleeve to hold the sleeve in assembled relation 40 with the actuator, said shoulders being spaced so that the distance therebetween is greater than the longitudinal length of the sleeve to provide for a lost motion between the sleeve and shoulv ders; spring means for urging the actuator in one direction, one of said shoulders engaging one end of the sleeve to separate the contacts; coacting means carried by the housing and the sleeve, said coacting means operating upon movement of the actuator causing one of the shoulders to o0 move the sleeve andthe reciprocable means to engage the stationary contacts with yielding pressure; coacting means carried by the housing and the sleeve to hold the reciprocable contact means under full pressure upon any slight retrograde movement of the actuator and also maintain full pressure contact between the contacts up to the time of separation when the coacting means functions to move the sleeve relative to the actuator to separate the contacts quickly; and means for 00 limiting the movement of the sleeve toward the switch opening position. 5. In an electric switch the combination of a reciprocable sleeve; a cam secured to the sleeve and movable therewith, said cams having oppo- 05 sitely disposed sloping sides; a yieldable contact reciprocably mounted on the sleeve and actuated by the sleeve to open and closed positions; a shaft reciprocably mounted in the sleeve; a spring urging the shaft in one direction; means carried by 7o the shaft at each end of the sleeve for actuating operating with the cam so that when the shaft is actuated to move the sleeve in one direction to move the contact in the closed position, the yieldable means will pass from one sloping side to the other to operate as the holding means to hold the sleeve against retrograde movement on slight retrograde movement of the shaft so as to prevent arcing between the contacts and said means operating as the actuating means when the shaft and sleeve are moved a certain distance in the reverse direction to move the sleeve relative to the shaft thereby separating the contacts quickly. j

6. In an' electric switch, the combination of a housing; a reciprocable sleeve mounted in the housing; a shaft reciprocably mounted in the sleeve; abutments carried by the shaft for moving the sleeve with the shaft in either direction; a contact reci'procably mounted on the sleeve and moved into a closed position when the sleeve is actuated by one of the abutments of the shaft; a cam secured to the sleeve and movable therewith, said cam having oppositely disposed inclined surfaces to provide a ridge; a spring urged member supported relative to the sleeve, said member being urged against one of the surfaces when the contact member is in an open position and adapted to pass over the ridge and engage the other surface when the contact member is in the closed position, said means when engaging the last mentioned surface holding the sleeve against retrograde movement on slight retrograde movement of the shaft and maintain the contact in the closed position up to the time the other abutment on the shaft engages the sleeve to move same a certain distance in the reverse direction until such time the spring urged member passes over thel ridge to engage the rst mentioned in- 'cline surface whereby said member will actuate the sleeve relative to the shaft to separate the contact member quickly.

7. In an electric switch the combination comprising, stationary contacts; a movable contact; a slidable member carrying cam means and supporting the movable contact; an actuator slidably mounted with respect to the slidable member; releasable holding means cooperating with the cam means; resilient means resisting movement of the actuator in one irection; resilient means urging the movable contact toward the stationary contacts; means for moving the actuator in one direction, said actuator when moved in said specified one direction is capable of moving a certain distance relative to the slidable member before engaging the slidable member to move same and the'movable contact into engagement with the stationary contacts, said slidable member gradually compressing the second mentioned resilient means after the movable contact engages the stationary contacts to increase the contact pressure between the contacts, and said releasable holding means cooperating with the cam means to hold the slidable member against retrogrademovement on slight retrograde movement of the

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