US2509835A

US2509835A - Snap switch

Info

Publication number: US2509835A
Application number: US717567A
Authority: US
Inventors: Robert E Moore
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-12-20
Filing date: 1946-12-20
Publication date: 1950-05-30
Anticipated expiration: 1967-05-30

Description

y 1950 R. E. MOORE 2,509,835

SNAP SWITCH Filed Dec. 20. 1946 2 S I1e ets-Sheet l ROBERT E. MOORE,

May 30, 1950 R. E. MOORE SNAP SWITCH Filed Dec. 20, 1946 2 Sheets-Sheet 2 gvwcmim R BRT MOQRE Patented May 30, 1950 UNITED STATES PATENT OFFICE ssar swr'rcn mam E Moore, salamims.- Application December 20, 1946, Serial N6. 717,567

to provide novel and improved switch mecha-' snap switch mecha- Claims. ,iorzoo-s'z) single push-button style constructed in accordance with one embodimentof my invention and nisms and operating means therefor. f

More particularly it is an object of the invene tion to provide in a snap switch mechanism a the same direction for successiveoperations of '10 thrust lever adapted to be actuated always inthe switch and including a movable-pivot. for

the lever and means for limiting said lever.

More particularly the travel of Y .45. .an object of the inven-- tion to provide in a switch of the snap type a rocking yoke adapted to be maintained by an over-center spring in either of two positions and in which a portion of the rocking yoke remote from its axis of rocking forms a fulcrum and mounting for an operating or. thrust lever adapted to receive a force in a direction approximately along its axis from suitable'actuating means to move the yoke to activate the spring.,

Such thrust lever' may or may not carry a movable contact forming a portion of the circuit of the Switch. I

One of the important features of the invention comprises a dual use of the over-center spring for actuating the yoke and contact and providing the return force for the operating member to insure it returning to its initial position after each operating thrust.

The switch of the present invention being particularlyadapted for automatic operation, one of the features of the invention comprises a unique combination transformer and operating magnet for the actuating plate of a switch constructed in accordance with the present invention, whereby remote low'voltage controls maybe resorted to for operating the switch with .the attendant advantages. 1

invention will be more apparent to those skilled in the 'art upon a consideration of the accompanying drawings and following specification wherein are disclosed several exemplary embodi ments of the switch mechanism and the operating means therefor, it being understood that'such variations, combinations and modifications of the same may be made as fall within the scope of the appended claims without departing from the v ofthe showing a single pole, double throw type:

Fig. 2 is aside elevation of the switch of Fig. 1 showing the-relationship of the thrust lever and operating plate;

Fig. 3 is a view similar to Fig. 2 01 a second embodiment of the switch havinga, diiferent con tact arrangement and including means for providing operating plate return from the main Fig.4 is a section taken on line 4-4 of Fig. 3; Fig. 5 is a top plan view of the switch of Fig. 3; Fig. 6 is an illustration ofa further arrangement I of thrust lever having unique limiting Fig. 'I is a' still further modification of thrust lever and cooperating operating plate and contact making stops; and

Fig. 8 is a schematic showing of combined switch operating magnetand transformers The present switches were developed in an effort to provide satisfactory forms of such switches-which reverse their contact positions once each time the actuating'lever or button is depressed and released. Most such mechanisms haveinherently low mechanical efiiciencies and hence require too great an eflort in their operation to warrant the use of low voltage actuators where desired. The mechanism suggested for use herein as suitable embodiments of the present invention have mechanical emciences above.

fifty percent. This efficiency may be defined as the ratio of the energy required for one operation of the switch to the basic energy required to separate the contacts to the dead-center toggle position.

- f a I I flange l4. Mounted on the frame are insulating Other and further objects and features of the blocks l6 and I! to which are suitably attached contact tabs 18 and is carrying respectively the facing contact buttons 20, 2| thereon, spaced apart as shown in Fig. 1. Movable contacts 22 carried by abent flange on the lower end of -switch, or if insulated from the thrust lever, are

connected .by a flexible p18 tionary terminal. I

Thejsnap action of the switch is accomplished by means of arockable 'U-shaped yoke 25 pro!- tail to a suitable staerably formed of rigid wire having the out-turned fulcrum ends 26 pivoted respectively in

notches

28 and 29 in the tab 30 in the front wall I 3 and in the back wall I 2. The wide bottom of the yoke has its center bent upwardly as at 30 to provide a stud for the helical expansion spring 3| the opposite end of which fits over stud 32 on arm 33 bent horizontal from the wall II and positioned vertically beneath the axis of pivot of the yoke. Under these conditions the spring becomes an over-center spring and will force and hold the yoke to either side of a plane passing through its axis pivot and the stud 32, depending on which side of the center it is initially placed.

To start the throw of the yoke by moving it beyond the dead-center position from whatever position of rest it may be in, the thrust lever 23 is fulcrumed on the bottom reach of the yoke as at 35 or on any suitable fulcrum remote from the yoke rocking axis. To insure the main portion of the thrust lever remaining parallel to the sides of the frame and of the yoke, it has an integral arm 36 extending parallel to reach 35 and carrying a tab 31, the latter being also fulcrumed on the yoke as clearly seen in Fig. 2. Rotation of the thrust lever in respect to the yoke may be limited by various means. As shown in Figs. 1 and 2 spaced stop arms 39 and 46, bent up from the sides of the thrust lever span one of the side wires of the yoke against which they alternatively engage, as seen in Fig. 1. Thus the contacts on the lower arm of the lever serve to limit the throw of the yoke. Q 1 For movement of the thrust lever substantially in line of its axis, resort is had to an operatingplate 42 having a pair of spaced apertures 43 therein each fitting over a narrow tongue 44 extending upwardly from the back wall I2. The body of the operating plate rests against the edge of frame wall l2 between the tongues. A narrow arm 46 extends from the plate beyond this fulcrum and is bent to provide an anchor for one end of the helical tension spring 41, the other end of which is anchored from arm 48 struck out from the back wall [2. This insures the movement of the operating plate in a clockwise direction as viewed from Fig. 2, such movement being limited by engagement of the far edge of the plate with the end face of a push button 56 working through an aperture in the top wall M of the frame. I

In operation the switch contacts change position once for each time that the button 56 is pressed and released. Upon such pressure the plate 42 moves downwardly in a counterclockwise direction and engages the upper end of thrust lever 23, forcing the latter downwardly and swinging the yoke in a clockwise direction,

the yoke limiting the movement so that the upper end of the thrust lever remains beneath the operating plate 42 ready for the next operation of the latter. The shoulder 5| on the side wall of the frame limits the downward movement of the operating plate 42. Final movement of the top of 23 does not occur until 42 is released but the desired contacts are already in engagement and only roll slightly.

The switch of Figs. 1 and 2 is not necessarily limited to the contact arrangement shown, for obviously various types of contacts may be mounted in other positions as long as at least one of them is carried by some portion of the switch which alternatively assumes one of two positions in which it remains until the next actuation of the push button.

The switch of Figs. 3, 4 and 5 makes use of the basic features already described and the frame construction need not be referred to more specifically except in so far as it differs from that already described. In this arrangement yoke 25' has its right hand journal 26 considerably longer than in the first embodiment and the fulcrum for the operating plate 42' is so positioned that the plane of the operating plate intersects this portion 26 where it is cut away to prevent interference therewith, as shown at 66. The portion 6| beyond this cutout engages beneath the under surface of the portion 26 as clearly seen in Fig. 3, so that it holds the plate cocked up in the position illustrated against the under face of push button 56. When plate 42' is depressed, portion 6| engages beneath 26 and lifts the whole side of the yoke sufficiently to compress the overcenter spring 3|, which thereby acts not only for its designated purpose but to maintain and return the operating lever to its upper position, thus dispensing with the operating plate spring 41 of Fig. 1.

In the second embodiment of the switch the over-center spring 3| bears against the bottom reach of the yoke, but its upper end, instead of engagin a stationary stud on the frame, is mounted over a nub portion 62 in the inner horizontal arm SI of a wire stirrup having a substantially vertical arm 64 offset therefrom by portion 65. Arm 64 merges into a horizontal portion 66 at the bottom which bears in a pair of indentations 61 in spaced cross strips 68 stamped out from the bottom wall 69 of the frame. The

outer horizontal arm 63 of the stirrup extends.

parallel to the axis of oscillation of the yoke and forms a bridging member adapted-to engage the spaced contact springs 16 mounted on an insulating block H carried by arm 12 of the frame. It thus bridges them to close the circuit. These contacts likewise act as a stop limiting the swinging of the stirrup under the action of spring 3! as viewed in Fig- 1, until the over-center spring to the position shown in Fig. 4. Movement of takes control and moves the yoke to its opposite position as determined by contact and stop on the lever, which partakes of a partial counterclockwise rotation.

An important feature of the arrangement is the sliding and rocking motions given to the movable contacts in respect to stationary contacts at the time of initiating movement of the switch parts, thus insuring that the contacts are free to separate when the spring takes control. As the spring swings the yoke over, contact 22 makes engagement with contact 26 and further movement of the yoke rotates thelever 23 in a counterclockwise direction as seen in Fig. 1 until stop stirrup 64 in the opposite direction when the yoke is swung over is limited by stop 13.

Thrust lever 23', which is preferably pivoted to the bottom element of the yoke, as in the earlier embodiment, carries stop lugs 39 and 46' to engage with the yoke side element, but since there are no contacts to limit the movement of the lower end of this lever it is provided'with spaced tines 15 and I6 straddling the bottom horizontal pivot portion 66 of the stirrup, which acts as a stop for one or the other of them, depending on the position of the thrust lever and thus limits the swing of the yoke.

In the operation of this embodiment an addi- 40 comes into engagement with the side arm of tional movable element is made use of to carry the movable contact; and it is actuated by the opposite end of the over-center spring. By this construction the contacts are completely removed from any possible manipulation by the operator which might cause arcing and are solely under control of the spring.

In Fig. 6 is illustrated a further embodiment of the thrust lever 23 capable of use with either type of switch shown in the first two embodiments. It is shown as fulcrumed on the yoke element of 25 as in the previous embodiments and is provided with upper and lower lateral stop arrangements to limit its movement, one of which may be replaced by contacts. Thus the lower end is narrowed to a tongue I working in slot III in the bottom wall of the frame, the ends of which slot limit lateral movement of the lever. The upper end is likewise provided with a tongue I" working in slot I01 in the operating plate. The shoulders I02 0r I03 on the lever are selectively engaged by the lower surfaces I04 or I05 of the operating plate to impart thrust to the lever, while tongue I06 working in the slot selectively engages the ends of the slot to limit lateral movement of the top portion of the thrust lever. With this arrangement no stops are needed between the yoke and lever to limit relative movement therebetween.

In Fig. 7 the thrust lever 28 is arranged, at the bottom, the same as the one in Fig. 6. Top lateral stops are composed, at one side, of engaging contacts I08 and I I0 and the side of the lever and abutment H2 stamped from the wall of the frame on the other. In this construction the operating plate 42 is provided with companion indentations H5 and H6 above the respective stationary positions of the tip ill of lever 23 serving to prevent lateral travel of the upper end of the thrust lever when it is being pushed downwardly before the spring takes over, so that the contacts will not bind excessively but will be slid to insure their breaking loose and to keep them wiped clean.

Manifold economies may be effected in the wiring of buildings and houses by arranging control switches adjacent the apparatus which they control or at some point in the wiring system not requiring any excess working-voltage conductors and operating them remotely through low voltage circuits. This eliminates the need for large quantities of insulated and protected cable or conduit running to switches at distant points. The low. voltage conductors can be relatively small in size and have only nominal insulation. Conduit boxes would not be required for simple momentary contact push buttonswitches in control of these low voltage conductors.

Fig. 8 shows a simple magnetic means for actuating the operating plate 42 of any of the switches hereto described. Low voltage for the operating circuit is developed by a transformer 200, the magnetic circuit of which includes a closed core 2M and an L-

shaped'extension portion

202 and 203, on the upper free end of which the fulcrum for the combined plate and armature 42 is provided. A high voltage winding 204 passes through the window of the core 2M and is energized from the high voltage power source continuously. A low voltage winding 205 likewise passes through the window and ma be wound on the same or another leg of the core, and is connected to a control switch 206 by low voltage conductors 201.

In operation, with the circuit of 200 open, the magnetizingilux in the core is lnsufllcient to create enough flux in the air gap at 200 to attract the operating plate 42. When, however, the circuit of winding 205 is closed, the voltage induced in this winding causes a current flow therein producing a magneto-motive-force opposing that generated by winding 204, causing the current in this latter coil to increase to maintain the flux at its equilibrium value. The increased flux in the core is partially shunted to the air gap resulting in sufficient attraction to draw down plate 42 and operate the switch (not-shown) which may be mounted in the arms of the core L. Release of the push button 206 opens the low voltage winding circuit and the core flux drops sumciently for the armature attraction to be overcome by the spring 41 whereby plate 42 is lifted and made ready for the next operation of the switch. The amount of current used by primary winding 204 is inconsequential and usually insufllcient to operate the meter.

I claim:

1. In a switch .of the type described, in combination, a frame, an actuator adapted to be moved and returned for each opening and for each closing of the switch, a yoke mounted for rocking on said frame, an over-center spring having one end bearing on said yoke and the opposite end supported independently of said actuator, a thrust lever journalled on a portion of the yoke remote from its axis of rocking and extending partially between the yoke arms, said lever being arranged for transmitting thrust from the actuator to move the yoke from either position of rest sufficiently to start the spring over-center and to then cross the axis of rocking of the yoke when the actuator is returned, a stationary contact carried by said frame, and a second contact carried on one of the movable parts of the switch.

2. In a switch of the type described, in combination, a frame, a yoke mounted for rocking on said frame, an over-center spring having one end bearing on said yoke, a thrust lever journalled on a portion of the yoke remote from its axis of rocking and extending partially between the yoke arms, said lever being arranged for transmitting thrust to initially move the yoke from either position of rest sufficiently to start the spring over-center, a stationary contact carried by said frame, a second contact carried on one of the movable parts of the switch, cooperating means on and limiting relative rotation of the yoke and lever and means forming a stop for said lever opposite its journal from the said cooperating means.

3. In a switch of the type described, in combination, a frame, a yoke mounted for rocking on said frame, an over-center spring having one end bearing on said yoke, a thrust lever journalled on a portion of the yoke remote from its axis of rocking and having a portion extending between the yoke arms and beyond the axis, a plate rockably mounted on said frame, said lever being arranged for transmitting thrust from said plate to initially move the yoke from either position of rest sufilciently to start the spring over-center, a stationary contact carried by said frame, a second contact carried on one of the movable parts of the switch, means limiting relative rotation of the yoke and lever, and means limiting transverse movement of the lever.

4.'A snap switch assembly including a frame structure, a yoke mounted for rocking on said frame about an axis, an over-center spring arranged between the frame and yoke to control the position of the latter, a thrust lever journalled on said yoke about a second axis parallel to and remote from said first axis, said lever having a portion extending in the general direction of the. first axis, means limiting relative rotation of the lever and yoke, means including said spring to always position said lever portion to the same side of a plane through the said first axis of the yoke bisecting its angle of throw as the yoke is positioned, an operating plate adapted to be moved generally in the axial direction of said lever to impart a thrust to the said portion of the same and contacts fixed respectively to the frame and a movable part of the switch assembly.

5. The snap switch assembly as defined in claim 4 in which the operating plate is fulcrumed to the frame structure for movement about an axis at.

right angles to that of the yoke.

6. The snap switch assembly as defined in claim 4 in which the operating plate is fulcrumed to the frame and means associating said plate and yoke whereby said spring retracts the plate upon release after actuating said lever. l

7. A snap switch including a frame, a yoke pivoted for swinging in said frame about an axis, a stirrup pivoted for swinging in said frame about an axis parallel to and remote from said first axis, an over-center spring compressed between parts of said yoke and stirrup each remote from its axis, stops limiting movement of said stirrup, one of said stops comprising a stationary contact, a thrust lever pivoted to said yoke remote from the axis of the latter, a portion of the lever extending generally toward the yoke axis, and means including the spring causing the said portion to assume a position divergent to the plane of said yoke and on the opposite side thereof from the spring,

8. The switch as defined in claim 7 in which said last mentioned means also include stops limiting relative motion of the yoke and lever.

9. The switch as defined in claim 7 in which said last mentioned means also include stops limiting relative motion of the yoke and lever and stops limiting movement of theyoke in respect to the frame.

10. A snap switch mechanism including a frame, a yoke pivoted for swinging in said frame, an over-center spring effective between the frame and yoke, a lever journalled intermediate its ends to a portion of the yoke remote from its pivots, spaced means on said frame to be alternatively engaged by one end of said lever to limit its transverse motion, means on said frame to be alternatively engaged by the other end of the lever to limit its transverse movement, and anactuating plate adapted to impart thrust to the last mentioned end of the lever in either of its stopped positions.

11. A snap switch mechanism as defined in claim 10 in which the last mentioned lever end and the actuating plate are provided with interfitting means at the said position.

12. The switch as claimed in claim 1 in which a stirrup fulcrumed to the frame remote from the yoke axis supports the opposite ends of the spring, said movable contact being mounted on said stirrup.

13. A snap switch including a frame, a yoke 8 pivoted for swinging in said frame about an axis, a stirrup pivoted for swinging in said frame about an axis parallel to and remote from said first axis. an over-center spring compressed betweenparts of said yoke and stirrup each remote from its axis, stops limiting movement of said stirrup, one of said stops comprising a stationary' contact, a thrust lever pivotedto said yoke remote from the axis of the latter, a portion of the lever extending generally toward the yoke axis, means including the spring causing the said portion to assume a position divergent to the plane of said yoke and on the opposite side thereof from the spring, said stirrup comprising the other contact and means limiting the relative rotational movement of lever and yoke.

14. A snap switch mechanism including a frame, a yoke pivoted for swinging in said frame. an over-center spring effective between the frame and yoke, a lever journalled intermediate its ends to a portion of the yoke remote from its pivots, spaced means on said frame to be alternatively engaged by one end of said lever to limit its transverse motion, spaced means on the opposite end of the lever to alternatively engage the yoke to limit relative movement of the lever thereto, an actuating plate adapted to impart thrust to the last mentioned end of the lever in either of its stopped positions, a contact carried by and insulated from the frame and an engaging contact movable relative thereto under the action of said yoke.

15. In a switch of the type described, in combination, a stationary frame, a movable member mounted for rocking on said frame about an axis, a movable thrust lever pivoted on a portion oi said rocking member remote from its axis oi rocking, an over-center spring bearing on one of the movable parts at a point remote from the said axis, said thrust lever being arranged for transmitting thrust for compressing the spring to initially move the rocking member from either position of rest sufliciently to start the spring over center, a stirrup pivoted on said frame on an axis parallel to and remote from the axis of rocking of said member, the opposite end of said spring being mounted on the stirrup remote from its axis, a contact carried by a. part of the stirrup, and a cooperating contact carried by said frame. ROBERT E. MOORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS