US3525834A - Quiet snap action electric switch - Google Patents

Description

8- 25, 1970 R. G. MUNROE 3,525,834

QUIET SNAP ACTION ELECTRIC SWITCH Filed June 6, 1968 2 Sheets-Sheet 1 P INVENTOR.

RONALD G. MUNROE I 00 65 8522 33 a0 20 I ATTORNEYS Aug. 25, 1970 R. G. MUNROE QUIET SNAP ACTION ELECTI QIC SWITCH 2 Sheets-Sheet 22 Filed June 6, 1968 FIGJO M mm T U M M V G L .A w p R t Q g m Y B ATTORNEYS United States Patent 3,525,834 QUIET SNAP ACTION ELECTRIC SWITCH Ronald G. Munroe, Old Bridge, N.J., assignor to Eagle Electric Mfg. Co., Incorporated, Long Island City,

N.Y., a corporation of New York Filed June 6, 1968, Ser. No. 735,148 Int. Cl. H01h 21/40 U.S. U. ZOfi bB 12 Claims ABSTRACT OF THE DISCLOSURE Single contact and double contact switches are disclosed using a ball at the top of a spring for obtaining the snapaction. In the single contact switch, a toggle lever, in one position, spaces the ball from the movable contact, and in another position causes the ball to press the movable contact arm against the stationary contact. These parts are mounted in an open top insulating casing which also contains the contact terminals therewithin. An insulating cover plate received within the open end of the casing, has a pair of downwardly facing half bearing grooves which are located above the top ends of pillars in the casing. The cover plate has a large slot to pass the handle of the toggle lever which has a pair of oppositely extending central, transverse trunnions received in said bearing grooves. A downwardly extending wedge in the toggle lever engages the spring mounted ball. A rubber pad is inserted under the cover plate and overlies a pair of abutment posts in the casing disposed in a plate perpen dicular to said pillars and disposed therebetween. The ends of the rubber pad are adapted to be engaged alternately by outwardly extending arms on the toggle lever as the toggle lever is oscillated. Contact of these arms with the rubber pad is silenced because of the resiliency of the rubber pad. The rubber pad has a central hole through which the wedge on the toggle lever projects downwardly. The rubber pad is squeezed between the upper ends of the pillars and the trunnions to frictionally bind the toggle lever and prevent slop and eliminate noise of operation of the lever.

A tongue on the rubber pad projects down from one end of the opening in the pad, to lie between the side of the ball remote from the movable contact arm and the adjacent post to provide a noise reducing abutment for the ball to hit against when it moves away from the movable contact. This tongue is narrow enough to move between the two pillars and into the ball passage, and stops the ball so thtt it has less travel until it hits the movable contact in the on" position. This reduction of travel reduces some of the momentum from the ball when fiipped to the on position and further silences the switch.

The double contact switch has two movable contacts disposed on opposite sides of the ball and incorporates a similar rubber band to squeeze between the trunnions and the upper ends of the pillars, and to be contacted by the arms of the toggle lever.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a snap-action toggle lever operated switch with means to silence the switch and to eliminate slop in the action of the toggle lever.

Description of the prior art Snap-action switches with contact dampening means have been known. In one such device, rubber sleeves are placed around the posts and the ball is pressed by the toggle lever to move a movable contact against a sleeve in on position and the ball against the opposed post in oil position. No means was provided in such device to remove slop from the toggle lever or to prevent noise of operation of said lever.

In another prior device, the fixed contacts were mounted on rubber bumpers but did not eliminate slopin the action of the toggle lever.

In yet another prior device dampening means was interposed between the layer and the movable contacts but no dampening means was interposed between trunnions and their hearing, or between the ball and a fixed post of the housing.

In yet another prior art device, a toggle lever has a cam to contact and rub against a resilient cover plate for the switch housing to retard motion of the toggle lever.

Other objects of this invention will in part be obvious and in part hereinafter pointed out.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts which will be exemplified in the constructions hereinafter described, and of which the scope of invention will be indicated in the following claims.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing, in which are shown various illustrative embodiments of this invention,

FIG. 1 is a top plan view of a single contact switch embodying the invention;

FIG. 2 is a cross-sectional view taken on line 2-2 of of FIG. 1 and showing the switch in ofi position;

FIG. 3 is a partial view similar to FIG. 2, but showing the switch in on position;

FIG. 4 is a cross-sectional view taken on line 44 of FIG. 2;

FIG. 5 is a partial top view similar to FIG. 4, but showing the on position of the switch;

FIG. 6 is a perspective view of the rubber pad shown in FIGS. 2, 3, 4 and 5;

FIG. 7 is a top view of a double contact switch embodying the invention, but with the strap and housing cover removed;

FIG. 8 is a cross-sectional view taken on line 8-8 of FIG. 7;

FIG. 9 is a cross-sectional view taken on line 99 of FIG. 7; and

FIG. 10 is a perspective view of the rubber pad shown in FIGS. 8 and 9 and shown in dot-dash lines in FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in detail to the drawing, FIGS. 1 to 6 illustrate a single contact switch 10 embodying the invention.

Switch 10 comprises a metal strap 11 clamping a cover plate 13 to a case 12. Said cover serves to hold a toggle lever 14 in operative position relative to the case for actuating a movable contact 15. The case 12 and cover 13 comprise a casing. The cover has end internal positioning shoulders extending into the case 12.

Said case 12, cover 13 and toggle lever 14 are made of molded electrically insulating rigid material, and strap 11 is made of sheet metal, as a stamping.

Case 12 comprises a bottom wall 18 from the ends of which, end walls 19 and front and rear walls 20 project upwardly. Walls 20 interconnect end walls 19. Said walls 19, 20 have coplanar upper end edges 19a, 20a.

Case 12a of a double contact switch 10a illustrated in FIGS. 7 to 10, is substantially similar to casing 12, with exception of some details which will be referred to hereinafter, and the same reference numerals will be used for similar parts of cases 12 and 1211. Some details of the case 3 are more clearly illustrated in FIGS. 7 to 10 than in FIGS. 1-6. The left end of the drawing of case 12 is shown at the right end of the drawing of case 12a.

Thus case '12a also has a bottom wall 18, end walls 19 having upper edges 19a and front and rear walls 20 having upper edges 20a. Each of end walls 19 has a central vertical outer recess 23 which narrows at its upper end as at 24, between a pair of spaced, aligned horizontalledges 25 projecting outwardly from the upper end of said end wall. The undersides of the inner ends of said ledges 25 form undershoulders 26 for the purpose hereinafter appearing.

Cases '12, 12a are each formed adjacent the underside of the bottom wall 18 and adjacent one end, with downwardly projecting projections 27 formed in case 12a with through openings 28 and with through slots 29 adjacent said projections. Said openings and slots are eliminated at one end of case 12.

Both cases 12 and 12a are formed with a pair of integral parallel upstanding pillars 30 having narrowed rib tips 31. The upper end edges 32 of tips 31 are aligned and are disposed in a plane substantially slightly above the level of the underside of cover 13.

Said pillars 30 are spaced equally from end walls 19; are spaced inwardly from front and rear walls 20; and extend upwardly from the bottom wall :18. Said pillars have shoulders 33 disposed in a plane slightly below upper edges 32.

.Both cases, 12, 12a are formed with integral abutment posts 35 which extend upwardly from the bottom wall 18 and are disposed in a longitudinal central plane perpendicular to the bottom wall. Said posts are hence in a plane spaced centrally between pillars 30. Posts 35 are connected near bottom wall '18 to end walls 19 by webs 36. Between posts 35 and also between pillars 30 is a central vertical socket 37 having an upwardly extending central pin 37a for the purpose hereinafter appearing.

Walls 20 are formed with aligned through openings 40 extending up from bottom wall 18. Said openings 40 have upper semi-circular edges 41. Bottom wall 18 is notched as at 18a at the lower ends of openings 40.

The cover 13 fits into the upper end of case 12 (or 12a) and has an undersurface disposed in a plane above the plane of the upper ends of posts 35; and somewhat above shoulders 33 of pillars 30. Said cover rests on internal corner shoulders 13a and has a central longitudinal through opening 44, an upper perimetral shoulder 45 and a rectangular portion 46 projecting up above said shoulder 45. Shoulder 45 surrounds said rectangular portion 46. The ends of slot 44 may be upwardly and inwardly curved. The cover has end walls 47 interconnected by front and rear portions 48. Portions 48 have at their inner surfaces, central notches (half bearings) 50, semi-circular in shape at their upper ends, thereby forming half hearings on which to rock or oscillate the toggle lever I14, as will appear hereinafter.

The cover 13 is held clamped to the casing 12 by said strap 11 in the manner to be explained. Said strap 11 has a flat central portion formed with a central rectangular opening 56 the edges of which rest on shoulder 45; and said portion 46 of the cover projects upwardly through said opening. Said strap has downwardly bent inverted T- shaped portions 58, cut from the metal of the strap, each comprising a narrow portion 59 passing through narrow, slot portion 24, and a wide crossing portion engaging in slot 23 and beneath the ledges 25 to hold the strap to the case 12. Strap 11 may be of conventional construction.

The toggle lever 14 comprises a central upwardly extending handle 60 from the lower end of which extend arms 61 disposed longitudinally of the slot 44, Extending sideways from the lever are similar, oppositely extending, aligned trunnions 62 projecting into the half bearing notches 50, whereby to permit said toggle lever to be rocked or oscillated. Arms 61 may be hollowed as shown at 63 to reduce weight. As the lever 14 is rock-ed, one arm moves down toward the upper end of one abutment 4 post 35, while the other arm moves away from the other post.

Projecting down at the underside of said lever is a central lug or wedge 65 located between pillars 30 and also between posts 35.

Disposed in socket 37 is a coil compression spring 70 at the upper end of which is mounted a steel ball 71 which engages the lower end or tip of the wedge 65. The centering pin 37a projects up into the lower end of spring 70. The ball releasably retains the toggle lever in one or the other of its extreme angular positions by reason of being pressed by spring 70 against one side or the other of the tip of wedge 65. The upper end of ball 71 is substantially at the level of the upper ends of posts 35 and the tip of wedge 65 projects somewhat therebelow.

Mounted in one end of cases 12 and 12a, on bottom wall 1 8 and on opposite sides of the adjacent post 35 and web 36, are spring contacts 80. The contacts are located at the left end of case 12 and at both ends of case 12a.

Each contact has a vertical arm 80a contacting a pillar 30, a horizontal portion 80b extending therefrom and resting on bottom wall 18 and a spring finger 80c inclined upwardly and outwardly from portion 80b and overlying an opening 28.

Also at the left end of case 12 (and both ends of case 12a) there is a contact comprising a wall 85a contacting the inner side of a wall 20 (lower wall 20 as shown in FIG. 4 and upper wall 20 as shown in FIG. 7). Wall 85a covers opening 40 of the adjacent wall 20 of the case. Wall 85a has an extruded internally threaded boss 85b which receives the shank 86a of a screw 86. The head 86b of said screw can fit in said opening 41 and constitutes a terminal post for a conductor wire. Extending at right angles to wall 85a is a wall 850 contacting an adjacent end wall 19 and having edge contact with web 36. Wall 85c is formed with an inner vertical groove 85d disposed above one opening 28. A conductor wire pushed up through hole 28 is gripped between inclined tongue 80c and Wall 85c.

Wall 85a is formed with a horizontal pocket disposed in a vertical plane to fixedly receive one end of a movable contact member 87 which has a spring ann 87a traversing the casing and disposed between the adjacent post 35 and the ball 71. This arm carries the movable contact 15. The arm 87a is disposed between pillars 30 and said adjacent post 35 (shown at left side of FIG. 4).

Referring now specifically to case -12 and FIGS. 1 to 6, it will be seen that a second contact 90 is disposed at left end of said case and is substantially similar to contact 85 and is substantially symmetrical thereto. However, contact 90 is formed at the inner side of wall 90a (corresponding to wall 85a of contact 85), with an offset arm 90b constituting a fixed contact disposed in opposed aligned relation to the outer end of movable contact arm 87a.

In the position of FIG. 2, the switch is off, and the tip of wedge 65 is located between the movable contact arm 87a and the ball 71. When the toggle lever is rocked from the position of FIG. 2 to the position of FIG. 3, the ball is first depressed against spring 70, and then as the wedge rides over the ball, said ball springs up on the opposite side of the wedge 65 and presses the movable contact against the fixed contact for achieving the on position. In both positions, the spring pressing the ball against wedge 65, releasably holds the toggle lever in one position or the other.

Highly improved means is provided to silence the switch 10. To this end a fiat pad or piece of rubber or neoprene or other elastic rubber-like or soft padding damping material is placed over the upper ends of posts 35. Pad 100 may be rectangular shape and has a tongue 101 cut from the material thereof and depressed to form an opening 103. The ends of the pad rest on the upper surface of abutment posts 35. The central portions 102 of the pad, on opposite sides of opening 103, overlie the upper ends of pillars 30 and are squeezed between the trunnions 62 and the upper edges of pillar portions 31 forcing the trunnions to bottom in the half bearings 50. Thus parts of portions 102 of the pad project up into grooves 50 in the cover 13. Most of the noise in a switch of this type is occasioned by the slop of the toggle lever pivots or trunnions when the switch is thrown. The friction of the rubber pad between the trunnions and the pillars and the consequent friction between the trunnions and the half bearings eliminates this slop.

The tongue 101 is disposed between the ball 71 and the post 35, remote from the movable contact in the oil position of the switch. The tongue is narrow enough to move between pillars 30 into the ball passage. The wedge 65 projects down through hole 103.

As shown in FIG. 2, the tongue 101 may move between pillars 30. Thus when the toggle lever moves from position of FIG. 2 to the position of FIG. 3, the ball having been moved to the left by tongue 101, as shown in FIG. 2, has less length of travel before it strikes the movable contact to move it into engagement with the fixed contact as shown in FIG. 3. This reduction of travel takes some of the momentum away from the ball when flipped to the on position and silences the switch.

When the toggle lever is thrown, one or the other end of arms 61 of the toggle lever contacts the pad 100 which provides a dampening of noise for the ends of the lever. Ordinarily, if the ends of the lever were to strike solid mold material (such as Bakelite), in contacting the upper ends of the posts 35, they would create clicking noises.

The ball, when moving from on to off position, is prevented from striking the inside of the post 35 at the right side of FIG. 3, by reason of the intervening flap or tongue llllll which dampens the noise and prevents clicking.

Referring now specifially to case 12a and the double throw contact switch a of FIGS. 7 to 10, it will be seen that this switch has two contacts 85 along the wall (shown at top of FIG. 7). These contacts 85 are symmetrical with respect to each other and carry screws 86 and cooperate with contacts 80 at both ends of the casing.

At the left end of said wall 20 there is also an opening 40 to receive the head of screw 86. In FIG. 7, the screws 86 (at the top of said figure) are shown partially unscrewed, only for purpose of illustration.

At the wall 20 shown at bottom of FIG. 7 there is a single contact member 110 which comprises two fixed contacts 112 joined together by a central portion 111.

As the toggle lever 14 of switch 10a is flipped, in either direction, a closed contact is opened and an open contact is closed.

Interposed between the toggle lever and the upper ends of posts 35 and pillars 30 is a pad or plate 120 of rubber or rubber-like material such as neoprene or any other soft padding or damping material.

Pad 120 has a central rectangular hole 121 through which the wedge 65 projects downwardly and is engaged by the ball 71. The ends of pad 120 are alternately contacted by the undersides of the arms 61 of the toggle lever to dampen or eliminate noise. Portions .122 of the pad on opposite sides of hole 121 are squeezed between trunnions 62 and upper ends of pillars 30 to create friction as aforementioned and prevent slop between the toggle lever and the casing.

It will be observed that case 12 must be made with openings 40 at one end only (left ends of walls 20 in FIG. 4). Case 12a has two openings 40 on one wall 20 (top wall shown in FIG. 7), and only one such opening 40 on the other wall 20 (shown at lower side of FIG. 7).

Therefore, only one end of contact 110 (right end as shown in FIG. 7) carries a screw 86.

It will thus be seen that there are provided articles in which the several objects of this invention are achieved,

and which are well adapted to meet the conditions of practical use.

As possible embodiments might be made of the above invention, and as various changes might be made in the embodiments above set forth, it is to be understood that all matter herein set forth or shown in the accompanying drawings, is to be interpreted as illustrative only.

I claim:

1. A switch comprising a casing a toggle lever, means for mounting said lever in said casing for oscillatory movement, said mounting means comprising trunnion means on said lever, bearing means in said casing receiving said trunnion means, pillar means in said casing, said pillar means being directly opposed to said bearing means and means interposed between and contacting said trunnion means and said pillar means to hold said trunnion means against said bearing means and to prevent a sloppy fit between said lever and said casing, said lever having a portion projecting through an opening in said casing for manual engagement to oscillate said lever, means for resiliently urging said lever toward and for releasably retaining said lever at alternate opposite ends of its angle of oscillation, normally open contacts in said casing, said urging and retaining means including means to close said contacts in one end position of said toggle lever and to allow said contacts to open in the opposite end position of said toggle lever, said lever having a pair of oppositely extending arms, rigid abutment means in said casing, and shock absorbing means interposed between said abutment means and arms and positioned to be alternately struck by said arms, respectively, as said lever is oscillated, to dampen noise, said shock absorbing means and said hold and prevent means comprising difierent parts of a single pad of rubber-like material.

2. A switch comprising a casing, a toggle lever, means for mounting said lever in said casing for oscillatory movement, said lever having a portion projecting through an opening in said casing for manual engagement to oscillate said lever, means for resiliently urging said lever toward and for releasably retaining said lever at alternate opposite ends of its angle of oscillation, normally open contacts in said casing, said means for resiliently urging said lever comprising a coil compression spring in said casing and a ball mounted on one end of said spring, said lever having a lug to engage, depress and ride over said ball as said lever is oscillated, said ball closing said contacts in one end position of said toggle lever and allowing said contacts to open in the opposite end position of said toggle lever, said lever having a pair of oppositely extending arms, rigid abutment means in said casing, and shock absorbing means interposed between said abutment means and arms and positioned to be alternately struck by said arms, respectively, as said lever is oscillated, to dampen noise, said shock absorbing means comprising a pad of rubberlike material on said abutment means having an integral tongue out from said pad and projecting between said abutment means and ball, on one angular position of said lever.

13. The combination of claim 1, said trunnion mounting means comprising a pair of oppositely extending aligned trnnnions on said lever, said bearing means comprising a pair of bearings receiving said trunnions, said pillar means being directly opposed to said bearing means, said pillar means comprising a pair of spaced pillars integral with said casing, said means interposed between said abutment means and arms comprising a pad of rubber-like material, and said shock absorbing means interposed between said pillar means and said trunnion means comprising spaced portions of said pad interposed between said pair of pillars and said pair of trunnions.

4. The combination of claim 3, said means for resiliently urging said lever comprising a coil compression spring in said casing, a ball mounted on said spring, said 7 lever having a lug to engage, depress and ride over said ball as said lever is oscillated, said pad having an integral tongue cut from said pad and projecting between said abutment means and ball in one angular position of said lever.

5. The combination of claim 2, said tongue when depressed from the plane of said pad forming an opening, and said lug projecting through said opening in said pad.

6. The combination of claim 1, said means for resiliently urgng said lever comprising a coil compression spring in said casing, a ball mounted on one end of said spring, said lever having a lug to engage and depress said ball and ride over said ball, as said lever is oscillated, said pad comprising an integral tongue out from said pad, said abutment means comprising a pair of posts integral with said casing, said tongue projecting between one of said posts and said ball, in one angular position of said lever, and between said lug and said one of said posts in the opposite position of said lever.

7. The combination of claim 6, said tongue when moved out of the plane of said pad, forming an opening in said pad, and said lug projecting through said opening in said pad.

8. The combination of claim 4, said tongue being narrower than the space between said pillars and movable between said pair of spaced pillars to push said ball toward said contact when said contacts are in open condition.

9. The combination of claim 7, said pillar means comprising a pair of spaced pillars, and said tongue being movable between said pillars.

10. A switch comprising a casing, a toggle lever, means for mounting said lever in said casing for oscillatory movement, said lever having a portion projecting through an opening in said casing for manual engagement to oscillate said lever, means for resiliently urging said lever toward and for releasably retaining said lever at alternate opposite ends of its angle of oscillation, normally open contacts in said casing, said urging and retaining means including means to close said contacts in one end position of said toggle lever and to allow said contacts to open in the opposite end position of said toggle lever, said lever having a pair of oppositely extending arms, abutment means in said casing, said means for resiliently urging said lever comprising a coil compression spring in said casing, a ball mounted on one end of said spring, said lever having a lug to engage, depress and ride over said ball, as said lever is oscillated, and a pad of rubber-like material within said casing having an integral tongue projecting between said abutment means and ball in one angular position of said lever.

11. The combination of claim 10, said means for resiliently urging said lever comprising a coil compression spring in said casing, a ball mounted on one end of said spring, said lever having a lug to engage, depress and ride over said ball, as said lever is oscillated, abutment means within said casing, and shock absorbing means disposed between said abutment means and ball in one angular position of said lever.

12. The combination of claim 11, said tongue and said interposed means comprising parts of a single rubberlike pad.

References Cited UNITED STATES PATENTS 1,415,972 5/1922 Allen 20068 1,877,923 9/1932 Lucia 20068 2,648,73 1 8/ 1953 Despard. 3,172,972 3 /1965 Schleicher. 3,182,161 3/1965 Winter.

ROBERT K. SCHAEFER, Primary Examiner D. SMITH, JR., Assistant Examiner US. Cl. X.R. 20067, 166

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