US2195746A - Switch - Google Patents

Description

April 2,- 1940. R. H. HILL 2,195,746

swIfrcHj Filed .my 22, 195'/ A 2 sheets-sheet 1 47 INVENTOR ATTORNEYS April2,1940. RH. HM. 4 2,195,746

SWITCH Filed July 22, 1937 `2 Smets-sheet 2 Y 77 lNvENToR 7 .9/ fxaberz HM?! j 90 BY i? ii ATTORNEYS Patented Apr. 2, 1940 UNITED STATES PATENT oFFlcE SWITCH poration oi' Delaware Application July 22, ,1937, Serial No. 154,958 11 Claims. (Cl. 200 76) Another object is to provide a switch structure of the snap action character that is compact in form and which may be easily assembled and manufactured.

Another object of the invention is to provide a switch, in which the movable contact assembly is of the oating type, with means for effecting good I pressure contact between the contact elements during the period the circuit is closed and which provides for 4the greatest pressure Contact just before the circuit is broken.

20 Another object of the present invention is to provide a push button switch construction with means to actuate the movable Contact. in which the movable contact is beyond the control of the operator after the button has been depressed beyond a certain predetermined point.

Another object is to provide a push button switch construction for starting motor circuits which is comparatively easy to hold in a circuit closed position and which permits the push button to movein a return direction a certain distance, without aflectingthe contact pressure.

Further objects and advantages oi the preslent invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown. i f

In the drawings: Y

Fig. 1`is a view in elevation of the switch.

. Fig. 2 is an enlarged sectional view oi' the switch 50 Fig. 6 is an elevational view, partly in section,

showing a modification of a movable contact assembly in elevation.

Fig. 7 is a sectional view of the contact assembly shown in Fig. 6 and taken on the line 1-1 lill of Fig. 6.

Fig. 8 is a sectional view taken on the line 8-8 of Fig. 7.

`Referring to the drawings, the switch structure embodying the present invention comprises a metallic cup-shaped housingf2ll having a bottom Wall'2l provided with an opening 22 to receive a collar or sleeve 23. The sleeve is rigidly secured to the wall in any suitable manner. In the present instance the sleeve is provided with a. reduced portion projecting through the open-y ing 22 and spun over as at 24, against the under surface of the Wall 2|.

The sleeve 23 slidably supports a push-button 25 of insulating material. The button is provided with an annular recess 28 to form a hub rortion 2l. The hub portion supports a rod ,or actuator 28. substantially concentric with the sleeve 23, and extends into the housing 23. This rod is formed with a cylindrical portion 29. an intermediate cam portion which includes inclined o surfaces 3|. 32 and 33, and a cylindrical end portion 34, The inclined portion 32 is preferably a little steeper thanthe surface 33. The intermediate cam portion is so arranged that the base of the inclined surface 3| cooperates with the cylindrical portion 29 to form a shoulder 35 on the actuator. The inclined surfaces 3| and 324 are arranged to form a channel 36 and theinclined surfaces 32 and 33 meet to form a ridge 31.

A coiled spring 40 surrounds the rod 29 and so has one end seated in the recess 26 while the other end rests on a Washerl 4| which rests upon a stop washer 42 made of non-conducting material. The washer 42 is provided with a slot 43 which terminates into a central opening. This opening 35 forms a guide or bearing for the cylindrical portion 29 of the rod 28. The' washer 42 is preferably held against the bottom wall of the housing by the cooperation oi a spacer washer 44, a removable terminal assembly 45, an insulating sleeve 46 and a closure 41. In the present instance the washer 44 is formed with a central opening 48 of greater dimensions than the base. of the inclined portion 3| to permit same to pass therethrough and normally rest on the washer 42 which limits the outward movement of the rod 28. The washer 42 is also provided with radial slots 49 extending' from the boundary of the opening 48. These notches receive the head of the rivets 50 on the removable terminal assembly 45. 50

The terminal assembly comprises a disc 5| of non-conducting material having a central opening 52 in alignment with the opening 48 of the washer 44. The washer 5| is provided with notches 53 extending from the boundary of the 55 opening 52 to receive tangs 54 formed integral with the terminals 55, 56 and a dummy plate 51 to prevent the terminals and the plate from turning relative to the disc 5 I. The terminals and the plate are provided wtih notches 58 and 58a respectively to receive tongues 59 of similarly formed resilient blades 60. These blades are preferably arcuate in formation. A blade 60 is secured to each terminal and the dummy plate by rivets having the head 50 which project into the slots 49 of the disc 44. The terminals 55 and 56 are provided with projections 55a and 56a, respectively, which project beyond the housing. These projections are received by suitable apertures 62 provided in the closure 41. By this arrangement the terminal ends 55a and 56d are held free of the metal housing 20.

The closure 41 centrally supports a stop or cup member 65 and is rigidly secured thereto by a sleeve 66. The sleeve is provided with a flange 61 which engages the bottom wall of the cup and a reduced portion. This reduced portion extends through a central aperture provided in the closure riveted over a metal washer 68.

.The sleeve 56 provides a guide for the cylindrical end 34 of the rod or actuator 28, and the stop-cup 65 limits the downward movement of a movable contact assembly 1D.

A contact assembly 10, shown in Figs. 2, 3 and 5 comprises a body 1l of non-conducting material and is formed with a peripheral groove 12 with a transverse notch i3 formed therein, see Fig. 3. The groove 12 receives a resilient retainer band or snap ring 'I4 having a tongue 15. This tongue extends into the notch 1S to form an anchor for the band and prevents the band from rotating relative to the body il. 'Ihe body 1i has a central opening 15 which is slightly larger in dimensions than cross dimension of ridge 57 formed by the inclined surfaces 32 and 33 of the cam portion on the rod 25. A plurality of transverse passages 11 are formed in the body and each passage is adapted to receive a ball 18 and a coil spring 75. One end of each spring rests on the band 'i4 and the other end engages a ball 18 to urge the ball against the actuator or rod 28. Preferably two annular contact bridging members 80 are secured to the body 1I, one on each end of the body. These members are rrnly held to the body by rivets 8l, one of which is clearly shown in Fig. l. One of the bridging members 80 is adapted to engage the contacts 82 and a dummy contact 32a which are attached to the free ends of the resilient arcuate members 60 secured to the terminals 55, 5G and the plate 5l. The purpose of the third contact 82a attached to the member' which in turn is secured to the plate 51, and which is shown in the present instance constitutes a dummy contact, is to make a three point engagement for the contact assembly 45. By this arrangement the contact assembly 45 is prevented from rocking while in engagement with the contacts 82 and 82a. It is to be understood that the third contact, namely the contact 82a and its associated plate 51, may be used to control an auxiliary circuit, if so desired.

The modified form of a movable contact assembly 85 is shown in Figs. 6, '7 and 8. This assembly comprises a bridging member 90 which houses a plurality of discs 9| and 92 of nonconducting material, each disc having a central opening slightly larger in dimension than the' widened portion or ridge 31 of the cam portion on the rod lor actuator 28. The intermediate discs 92 are provided with oppositely disposed notches extending from the boundaries of the opening, which are covered by the discs 9i to provide recesses. Each recess receives a ball 1B and a spring 19. One end of each spring rests on the bottom of the recess and other end engages a ball to urge same against the actuator extending through the assembly.

To assemble the movable contact assembly 85, the bridging member 90 is first formed in cupshaped formatin as indicated by the dot and dash lines indicated in Fig. 8, then the discs 9| and 92, 'in the order shown, are placed into the cup. The end 90a is then spun over the outer disc 9| to securely hold all of the discs in their desired positions.

In assembling the switch proper, the compression spring 40 is first positioned into the recess 26 of the button 25, then the washer 4I is placed over the rod portion 29. The stop washer 42 is then fitted to the portion 29 whereby the spring 40 will urge the washer against the stop 35 on the rod 29. This assembly of parts is then inserted into the housing so that the button projects beyond the sleeve 25 and the washer 42 engages the bottom wall 2| of the housing 20. Then the spacing washer 44 and either the terminal assembly 35 or the assembly 85 is inserted in the housing and over the actuator followed by the sleeve 4G, after which the closure 41 is slid over the terminal projection 55a and 55a until the cover 47 engages the outer edge of the housing. The closure t1 is-provided with suitable peripheral notches 95 to receive tangs 56 formed integral with the housing 25, and bent over, to firmly secure the cover to the housing and hold the various elements in their normal position, as shown in Figs. l and 6.

When it is desired to operate the switch from the position shown in Fig. l to that shown in Fig. 5 to close a circuit, the operator depresses the button 25 causing the actuator 29 to move downwardly, as viewed in the drawings. As the actuator is moved downwardly the end 34 of the rod will be guided by the sleeve G6 and the balls 18 will be forced radially outward by the inclined surface 33 to compress the springs 13 to store up energy in the springs 1Q until the balls rest on the ridge 31. When the actuator has moved downwardly a predetermined distance so that the balls 18 pass the ridge 31' the springs 19 will then move the whole movable contact assembly with a snap action into en gagernent with the contacts 82 and 82a. 'I'he movement of the contact assembly is beyond the control of the operator once the balls pass the ridge 31. When the balls 18 are past the ridge 31, the springs 19 will cause the balls to slide down on the inclined surface 32 and constantly urge the contact assembly toward and against the contacts 82 and 82a, as indicated in Fig. 5, and place resilient members 60 under tension so as to provide a good contact pressure between the contacts. This arrangement also provides for a rubbing action between the contactsr on slight movements of the contact assembly when same is in engagement with the contacts 82. This rubbing action between the contacts will occur when the operator releases his hold slightly, while the switch is closed, as the contact assembly would move upwardly, as viewed in the drawings, by the spring 40 but the contacts would not be separated on slight movements to cause arcing or burning of the contacts. Thus, by this arrangement it is practi- As the actuator is on the return movement the cam surface 32 urges the balls outward to compress the springs 19l until the balls reach the While the springs 19 are being compressed they also urge the balls I8 against the inclined surface 32 tending to urge the contact assembly toward the contacts 82 and 82a thus constantly increasing the pressure contact between same until the balls reach the apex formed by the inclined surfaces 3l and 32 at which time the contact pressure is at its maximum. The instant the balls are past the ridge 31 the contact assembly 45 or 90 is instantly moved with a snap action to separate the contacts to an open position thus preventing arcing or burning of the contacts.

An important advantage resulting from this or other arrangements embodying this invention is that it decreases to a minimum the replacement of switches used for the primary starting. circuit for busses and trucks wherein a relative high amperage and high voltage is required normally about 2O amperes at 24 volts.

While lthe embodiment of the present invenlion as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming Within the scope of the claims which follow.

What is claimed is as follows:

l. An electric switch comprising, in combination; a cup-shaped housing; a unitary stationary contact: assembly comprising an insulating plate, terminals carried by -the' plate, said terminals comprising a' iiexible contact portion and a rigid portion secured tothe plate with the rigid portion continuing beyond the open end of the housing; an insulating sleeve; a closure for the housing having recesses to receive the rigid portions, said sleeve and closure cooperating to hold firmly the plate and the stationary contact assembly adjacent the bottom wall of the housing and insulating the rigid portion of the terminals from the housing; a movable contact assembly includinga Contact carrier, a bridging member attached to the carrier; a manually operated actuator sldably supported by the plate and the closure; cam means carried by the actuator; and spring urged balls Vcarried by the contact assembly and cooperating with the cam means to snapr the contact into enga-gement with the flexible contacts on movement of the actuator in one direction and to snap the Contact out-of engagement from the flexible contacts on moveating with the member to hold the terminal sup nient of the actuator inthe opposite direction.

2. An electric switch, comprising in combination, a cup-shaped casing; a removable block of non-conducting material located withinthe casing; terminal contacts carried by the block and having portions projecting beyond the open end el the casing; a sleeve of non-conducting material; a closure for the housing having openings to receive the projecting portions and also cov operating with the vsleeve to hold firmly the block adjacent the bottom lwall of the casing and insulate the terminals from the housing; and a contact raxially movable vwith a snap action` into and out of contact with the terminals.

3. An electric switch comprising in combination; a cup-shaped housing; a terminal support assembly removably supportedwithin the housing comprising -an insulating disc; terminals secured to the disc and having projections adapted to extend beyond the open end of the housing; resilient contact members greater in number than the terminals; secured to the disc and the terminals, said contact members being arranged in a circular row to provide for an equal pressure at all points for a movablel contact movable with: in the Vhousing to prevent rocking thereof; a non-conducting sleeve about the terminals; a closure for the housing provided with openings to receive the projections of the terminals, said rclosure cooperating with theA sleeve to hold the terminal assembly against the bottom' wall of the housing; and means for securing the closure to the housing.

4. An electric switch comprising in combination; a terminal support assembly including resilient members providing contact engaging portions equally spaced to provide for a three point engagementfor a movable contact to prevent rocking of 'the movable contact; an actuator for the movable contact; and coacting means carried by the actuator andthe movable contact to snap the movable contact into engagement with the resilient members to close an electric circuit, and said coacting means also operating to place the resilient members under tension whereby a full pressure contact between the resilient members and the movable contact is obtained up to the time of separation.

5. An electric switch comprising in combination; a housing; an insulating disc; a removable terminal support; an insulating sleeve; a

closure for 'the housing cooperating with the sleeve4 for holding the disc and support in a deflnite position within the housing; a movable contact assembly within the housing; a manually operated actuator mounted for straight-line movements and projecting through the movable contact assembly, said actuator provided with means on each side of the disc, said means cooperating with the disc to limit the movements of the actuator in either direction; coacting means carried by the actuator and the movable contact assembly to snap the movable contact assembly into and out of engagement with the terminals; and resilient means adapted for urging the actuator in one direction of its straightline movement when the actuator is manually operated -in another direction and released.

6. An electric switch comprising in combination; a cup-shaped housing; an insulating plate; a removable terminal support the terminals having portions extending beyond the open end of the housing; an insulating member; a closure for the housing having openings to receive the extending portions of the terminals and cooperport and plate against the bottom wall of the housing; a movable contact assembly within the housing; a manually actuated plungermounted for straight-line movements and extending through the movable contact assembly and provided with stop portions on each side of the plate, the stop portions cooperating with the plate to limit the movement of the plunger in either direction; coacting means carried by the plunger and the movable contact assembly to snap the assembly into engagement with the terminals upon manual movement of the plunger in one direction; and spring means for moving the plunger in the opposite direction upon release of the manual jections from the housing; a closure for the housactuated means causing the assembly to be snap actuated out oi engagement from the terminals.

7. A movable contact assembly for a switching mechanism comprising in combination; a body of insulating material formed with an axial bore to receive an actuator and having a plurality of radial bores communicating with the axial bore; a ball and a spring located in each radial bore; a retainer ring about the periphery of the body for closing one end of the radial bores, said ring forming a seat for one end of the springs whereby the springs will urge the balls against the actuator; and a bridging member 'applied to the faces of the body to expose a portion of the body between the actuator and the bridging member.

8. A movable contact assembly for a switching mechanism comprising in combination, a body of non-conducting material formed with a peripheral groove provided with a recess and having an axial bore to receive an actuator and having a plurality of radial bf res communicating with the axial bore and the groove; a ball and a ,spring located with each radial bore; a band located in the groove and extending over the radial bores to form seals for one end of the Spring whereby the springs will urge the balls toward the actuator, one end of the band being anchored in the recess to prevent rotary movement of the band relative to the body; and bridging members supplied to the faces of the body to expose a portion of the body between actuator and the bridging member.

9. An electric switch comprising in combination; a metallic cup-Shaped housing; a removable terminal support assembly located within the housing comprising terminals provided with contact portion and having projections adapted to extend beyond the open end of the housing; an insulating member for lining the interior wall of the housing and to insulate the terminal proing, said closure cooperating with the insulating member to hold iirmly the terminal support assembly against the closed end of the housing; an actuator carrying cam means; and a movable contact slidable on the actuator and carry spring urged balls cooperating with the cam means of the actuator whereby the movable contact will be snap actuated into and out of engagement with the terminal contact portions upon actuation of the actuator.

10. A movable contact assembly comprising in combination; a plurality of superposed discs of insulating material, each disc having a through opening to surround an actuator with the intermediate disc having a recess extending from its opening to receive spring urged means adapted to engage the actuator; and a bridging member for holding the discs together, said bridging member comprising a cup-shaped member having an apertured bottom wall through which the actuator may extend and against which the lowermost disc rest and having the open end bent inwardly over the uppermost disc.

11. An electric switch, comprising in combination, a cup-shaped housing; a removable block located within the housing; terminal contacts carried by the block and having portions projecting outside the housing; a sleeve of insulating material; a closure for the housing, said closure cooperating with the sleeve to hold rmly the block against the bottom wall of the housing and to insulate the terminals from the housing; a movable Contact normally out of engagement with the terminals; and means extending through the movable contact ando'perable for actuating the movable Contact with a snap action into and out oi engagement with the terminals.

ROBERT H. HILL.

Images