US2024273A - Toggle switch - Google Patents

Description

Dec. 17, 1935. w. L.. BUTLER 2,024,273

TOGGLE SWITCH A mw 'gn/vento Urol v W. L. BUTLER Dec. 17, 1935.

TOGGLE SWITCH Filed Jan. 8, 1951 2 Sheets-Sheet 2 han@ Dec. 17, 1935 UNITED STATES PATENT ori-ICE TOGGLE SWITCH Application January 8, 1931, Serial No. 507,473

12 Claims.

This invention relates tornew and useful improvements in snap or toggle switches.

' An important object of the invention is to provide a switch oi the above type in which vibration of the switch blade is reduced to the minimum consistent with economy of manufacture.

' Switches of the type now in general use on heavy loads of incandescent electric lamps, possess switch blades subject to vibration which causes excessive arcing, thereby resulting in detrimental eilects upon the switch blade and the stationary contacts with which it'cooperates. The vibration of the switch blade occurs only for a small fraction of a second when the switch is thrown to on and oi positions and is most detrimental when the switch is turned to an on position due to the fact that the resistance to the current oiered by the incandescent lamps in circuit with the switch is comparatively low when the lamp lament is comparatively cool or at room temperature, thereby permitting a. greater ilow of current through the switch during this interval 'and until theA filament becomes heated and creates more resistance to the current. The rst 2:, inrush of current to these lamps has been found to be as much as ilfteen times the normal value.

Consequently, vibration of the switch blade at this time results in arcing between the contacts which burns and pits the same to such an extent that their life is greatly reduced. 1t is, therefore, the primary object of the invention to reduce the vibration of the switch blade to the minimum.

Another important object of the invention is to arrange the stationary contacts in such a manner to quench any sparks resulting from any possible arcing between the same and the movable switch blade.

Another important object of the invention is to provide an arrangement in which the switch blade can be constructed comparatively thick and substantially unyielding, whereby its life may be increased; such blade being normally urged to a position to elciently engage the stationary contacts by means of a structurally separate spring element. Due to the spring element being structurally separate from the switch blade, the latter is not subjected to the annealing effects of any arcing between the switch blade and the station- 50 ary contacts. A

A still further object of the invention is to cause the ends of the movable switch blade to directly engage the walls of the insulated support as it moves to on and olf positions whereby 55 the blade is wiped and kept clean.

Other objects and advantages of the invention will become apparent during the course of the following description.

In the accompanying drawings, forming a part of the description, wherein like numerals are 5 employed to designate like parts throughout the several views; and wherein those parts of the device bearing reference numerals with coemcients throughout the several views correspond to the parts bearing the basic or plain identifying nu- 10 merals, except where otherwise noted.

Figure 1 is a top plan of a toggle switch embodying the invention.

Figure 2 is a longitudinal vertical section through the insulator casing showing the station- 15 ary contacts in position.

Figure 3 is a scattered view of parts of the switch constituting certain improvements in the present invention and showing the switch blade and associated parts in perspective with a. sec- 20 tional perspective view of a wall of the switch casing with which the switch blade cooperates.

Figure 4 is a top plan of a switch showing a modied form of switch blade associated therewith, and 25 Figure 5 is a fragmentary top plan of a modified form of casing.

Figure 6 is a top plan of a switch embodying another form of switch blade.

Figure '7 is a scattered view of parts of the 30 switch shown in Figure 6, showing the switch blade and associated parts in perspective with a sectional perspective view of a modied wall construction.

Figure 8 is a perspective view of a modiiied 35 form of switch blade.

Figure 9 is a sectional perspective view of another modied form of wall, and

Figure 10 is a similar view of still another form of casing wall. 40

Referring now more particularly to the drawings for a detailed description of the various parts of the invention, the numeral 5 designates a switchcasing which may be constructed from any suitable insulating material such as porcelain or the like.

This casing or support has as usual, a cavity 6 which opens out into the top of the casing as is customary in this art, to receive and house a snap toggle mechanism such as disclosed in my copending application Serial No. 231,059. This toggle mechanism includes a crank or rocker 1 of U-shaped form having trunnions B and l projecting in opposite directions from the two arms thereof for pivotal support in V-shaped recesses Il provided in opposite side walls I i of the switch casing B.' 'I'his crank 1 may be stamped from any suitable sheet material of metal or insulatingtmaterial depending upon the manner desired for insulating the switch blade `from the mechanism.

'The bridge portion I2 of the rocker 1 is-equipped vwith a projection i3 adapted to enter the end of a compression coil spring, not shown, the other end of the spring being connected to the lower end of an operating lever I4 pivotally mounted in a bridge piece I5 spanning the cavity 6 in the cas- 'ing and secured to opposed walls thereof by the usual screws Ilv extending from the back of the casing. vAs iswell understood in the art, movement of the operating lever i4 upon its axis, causes the coil spring to be compressed and moved across the axis offthe crank 1 thereby impelling the same from one position of rest to another with a quick snap action. As a general description of this toggle mechanism is sufficient for a comprehensive understanding of the present improvements,

an illustration of the details thereof has been As is customary in this type of switch, a pairiof stationary contacts I1 and I8 are provided at opposite ends of the casing 5, one at the bottom of the cavity in the casing and the other at the top thereof as best shown in Figure 2. These contacts are, of course, provided with the usual binding posts I9 for connection of the wiring thereto. Unlike present arrangements, the contacts are positioned directly against a side wall of the casing, instead of being spaced therefrom in the customaryway.

In Figure 3, a side wall Il of the casing or support against which the stationary contacts are dis- Figure 2 to terminate in the angularly disposed end having the binding post I9 associated therewith. The elevated portion 22 at the opposite side of the central recess 20 terminates short of the top of the casing 5 to provide a second shallow recess 2| for the reception of the contact portion of the stationary contact i8. These two recesses 23 and 24 are preferably comparativelyshallow and are of a depth of approximately one-half the thickness of the contact portions of the-stationary contacts seated therein. This arrangement permits of seating approximately one-half the thickness of the contact portions of the stationary contacts in the shallow recesses so that the other half of the thickness of the contact portions projects slightly beyond the elevated surfaces 2 I and 22 of they casing as best seen in Figures 1 and 4.

If desired, the shallow recesses 23 and 24 may be entirely eliminated and the contact portions of.

the stationary contacts secured directly against a plain flat wall, but this necessitates allowance of more play in the mounting of the switch blade as will be more fully described hereinafter.

As shown in Figure 3, the bottom of the cavity is equipped with a pair of depressions 25 to alternately accommodate the ends of the switch blade in its on and olf positions. In a double pole or three point switch, the opposedA side -walls il 4 ment with the abutment shoulder 21.

of the casing are formed to correspond with the constructionof the side wall just described for the accommodation cf a second pair ofstationary contacts not shown.

' 'I'he crank 1 being formed from flat sheet mas terial causes its trunnions i and l to possess a substantially rectangular cross section. The trunnion 8 which may be shorterthan its brother when used in conjunction with a single pole switch. is bevelled to terminate in substantially al sharp point 26 for a purpose which will presently appear. Both trunnions are equipped on the upper edge with an abutment projection 21 in both modifications shown in Figures l and 4. The trunnion. 9 forms a mounting for a switch 15 blade 28 having. a pair of arms 2! projecting in opposite directions and terminating in winged contact ends 30. The central portion of this blade is provided'with a rectangular opening li f to receive the trunnion 9..' This opening 3i may be v20 of a size to slidingly nt the trunnion or it may be slightly larger to permit a looser fit thereon when the stationary contacts project the full thickness of their material from the face of the side wall I i. In any event, it is of a size whereby the switch 25 blade may be easily moved on or of! of the trunnion 9 without the use of tools.

Heretofore, switch blades in this type of switch have been constructed of lightI springy conductive material due to former arrangements of the sta- 30 tionary contacts, but such switch blades are short lived due to excessive pitting caused by arcing at, the contact ends. In the present improvements. the switch blade 28 may be constructed of rigid and heavier conductive material not necessarily a5 possessing inherent resilience due to the provision of a resilient element 32 normally urging the l switch blade toward thewall of the casing carrying the stationary contacts. 'This spring element is structurally separate from the switch blade and o may assume various forms. but is here shown in the form of a nat spring constructed from any suitable material. The spring 32 is provided with a central rectangular aperture 33 for loose mounting upon the trunnion 9 of the crank in engagea This spring blade 32 is provided with a pair of arms 34 extending in opposite directions from the center',

-which arms have their outer terminals-3B angularlyv disposed for engagement with the arms 29 of '50 the switch blade adjacent their outer ends. The extent of the angularly disposed ends 35 of the spring is determined by the distance between the shoulder 21 of the crank and the elevated surfaces 2| and 22 ofthe casing and is such as to normally 55 press the switch blade toward the cavity 2l tov span the same with the contact ends 3l of the switch blade forced into engagement with' the elevated plane surfaces 2| and 22 of the side wall',

or the two stationary contacts depending upon 00 the position of the crank 1. This action of the spring 32 naturally stresses the crank in the direction of its axis and toward the opposite side wall of the casing. It is for this reason that the end of the trunnion 8 is bevelled into a point soas to reduce friction between the crank and the side wall of recess I0. It will 'also be apparent that the spring blade 32 also stresses or urges the switch blade 28 in the direction of the axis 7o of the crank 1 and toward the side wall carrying the stationary contacts so as to firmly press the contact ends 30 of theswitch blade in engagement with the stationary contacts when the toggle mechanism isoperated through the actuating lever I4 tocompleteacimuitinwhichthe switch is included. f

Assuming that the switch is in an "oif position with the switch blade out of t with the stationary contacts l1 and I3, and it is desired to turn the switch on, the operating lever Mlsswunguponitsaxiscausing therockerl tobeswungonitstrunnionslandlwitha rapid snap movement induced by the toggle spring being moved across the axis of the rocker. The contact ends Il of the switch blade 23 being -spring urged into engagement with the elevated contacts. With the switch blade stressed toward the wall carrying the stationary contacts in the above manner, no interference with the successful.

interruption of the are when the switch is turned oif is experienced, since the presenceof the edges of the recesses 23 and 24 directly in the path of the arc, help to quench it. In this connection, it has been found desirable to maintain the contact surfaces of the stationary contacts slightly beyond the .elevatedsurfacesA 2| and 22 as this permits the switch blade to move more rapidly off of the contacts `when moving to an o position. The movement of the contact ends 30 of the switch blade over the elevated portions 2| and 22 sets up a slight abrasive action, especially when porcelain is employed in the construction of the casing, to wipe the contact ends of the blade and maintain them in a clean condition. `Due to the fact that the spring element 32 is structurally independent of the switch blade, it is removed from any possibility of being affected by any annealing heat present in the ends of the switch blade and permits of the switch blade being made of a very heavy and rugged construction.

In the event that the recesses or sockets 23 and 24 for the stationary contacts are eliminated and the contact portions of these stationary contacts are placed directly against the plane surface of the side wall as shown in Fig. 5, so that they project the full thickness of the metal from the face of the side wall; it is necessary for the switch blade 2B to have more lateral play, so that it can get up onto the stationary contacts i1 and I8. This may be accomplished by forming the mounting aperture 3| slightly larger than the cross sectional shape of the trunnion 9 to provide a floating connection of the switch blade with the crank or rocker giving it the necessary increased lateral movement. In such construction as shown in Fig. 5, the arrangement and construction of the spring 32 is such as to exert sulcient stress upon the switch blade 28 as to force it against the stationary contacts, but not sunlcient to force the blade into engagement with the wall Il when the blade is in an o position. Thus, in this modification, the frictional contact between the switch blade and wall il' is eliminated.

It will be evident, that if desired, the switch blade may be assembled rigidly with the rocker or crank, or made integral with it, and a spring eleis moved in the opposite ment 32 of suitable design provided which would act upon tbe switch blade or crank' to force the crank or rocker 'l and contact blade assembly toward the wall on which the stationary contacts are assembled. This, obviously, would necessitate 5 the allowance of slight axial movement of tho crank. When a double pole switch is provided as stated hereinbefore and a second switch blade assembly is mounted upon the trunnion l, the action of the switch will be the same except that v10 an additional spring element 32 would be provided on the trunnion 3 which would oppose the spring element 32 on the opposite end of the rocker and would balance the tendency of the rocker to move in the direction of its axis in either direction. In l5 this arrangement the end of the trunnion 3 can bepointed similartotheend 2Bsoasto reduce any possible friction should the urge of one spring element be stronger than the 'other'.

To turn the switch olf, operating lever Il 20 tion on its pivot to cause the rocker to swing on its axis and move the switch blade 23 oil' of the stationary contacts and I8. In this movement of the switch blade, its contact ends 33 have accelerated movement 26 in leaving the stationary contacts due to the latter being arranged beyond the elevated surfaces 2| and 22. After the contact ends 30 of the switch blade leave the stationary contacts they are forced into engagement with the elevated plane 30 surfaces 2l and 22 by the spring element 32 in the form of invention shown in Fig. l, where they are wiped and cleansed in their action of rubbing over the elevated surfaces, but in the form shown in Fig. 5, the contact blade 23 is not so forced 35 into engagement with the wall I as hereinbefore explained.

In Figure 4 another modification of the invention is illustrated which is identically the same as the preceding Figure i, except for the construc- 40 tion of the switch blade. In this instance, the switch blade 36 is illustrated as being a relatively thin piece of resilient conductive material having its' intermediate portion 31 bowed toimpart resilient flexibility thereto. This type of switch blade i5 does not necessitate the use of a separate spring element such as 32 in the preceding embodiments, due to the fact that it is inherently resilient. However, this switch blade 36 is provided with the same kind of aperture 3l as in the preceding 50 modification for association with the trunnion 3 of the rocker so that it abuts the stop shoulder 21 on the rocker when the contact ends of the switch blade are arranged in engagement with the stationary contacts I1 and I3. When in off 5 position, this switch blade 36, may or may not be urged against the side wall of the casing, but it is essential that it be stressed against the stop lug 2l of the rocker when its contact ends are arranged in engagement with the stationary contacts, to establish a sound electrical connection and to reduce vibration of the blade and consequent arcing. I

In Figures 6 and 7, further modiiications of the invention are shown and consist essentially of the formation of a one-piece rocker and switch blade and the construction of the wall of the casing toward which the switch blade is normally urged by reason of the inherent resilience of the rocker or a structurally separate spring element, such as described in connection with the form of invention shown in Figure 3. As stated previously those parts of the modification bearing reference numerals with coeilcients correspond with previously described `parts bearing basic or plain reference numerals. except where otherwise noted. and consequently auch parts will not be described in detail. v J

As particularly shown in Figure 7, the wall I la of the casing toward which the contact blade is portions provide ycounter-sinks for the contact` portions Il and il of the stationary contacts and as will be noted in Figure 6, the contact surfaces of the contact portions of the stationary contacts protrude a distance equal to substantially cne.

half the thickness of the contact portions, beyond the highest portions of the inclined surfaces 2|' and 22'. Of course, if desired, the contact portions of the stationary contacts may be arranged at a greater distance from the elevated portions or flush therewith, as may be desired; The purpose of the elevated inclined surfaces is to retard the snap action of the switch blade in progressively` increasing amplitude as the blade approaches the stationary contacts.

The oscillatory rocker Iza, shown in Figures 6 and 7, is of especially novel formation, in that the switch blade 29a with its guide wings 30a are formed as an integral part of one end of the rocker.v This unit is preferably constructed of conductive sheet metal and may be of a gauge rendering the switch blade substantially rigid to ably withstand the detrimental effects of any' tain resilient characteristics thereto, whereby they arms of lthe U-formation possess sufllcient resilience to normally be urged outwardly toward opposed side walls of the casing and to thereby normally urge the switch blade 29 toward the wall Ila of the casing carrying the stationary contacts, but not to a suflicient degree to cause engagement of the switch blade with said wall when the switch is in an off position. However, the arms of the rocker are normally stressed suiliciently to cause the switch/'blade to engage the inclined elevated surfaces 2|' and 22' in progressively increasing amplitude as they move toward the stationary contacts and after they have engaged the same are iirmly pressed by the resilience of the rocker into a firm electrical contact.

The arch portion of the rocker is provided with an up-struck lug I3a, which like the lug I3 of the form of rocker shown in Figure 3, is adapted to engage with one end of a compression spring, such as is common in the art. A trunnion 8a is formed integral with one of the arms of the rocker b'y cutting the arm transversely and bending 4the cut portion outwardly of the 'arm to extend in a plane at substantially right angles with the plane of the upright portion of this arm. 'I'his trunnion is preferably bevelled as at 26a to reduce the amount of friction between the rocker and casing at the point where the trunnion engages .with its V-shaped seat lila in the side wall.

-three lines at the medial portion of the switch blade and bending the cut portion outwardly, so that it, like the trunnion 8a, extends in a plane -at right angles to the plane of the switch blade oscars to engage in a v-shaped seat lla in the opposite aide wall ci the casing. If desired, this trunnion la may be clipped to provide it with a bevelled upper edge corresponding with and for the same purpose as the Vbevel Ita. With this construction, 5 it will be evident that the more or less pointed ends of the mounting portions 8a an'd lo -will be stressed into engagement with the opposed walls of the casing, so as to normally urge the switch blade `29a toward the wall bearing the stationary 10 contacts.

In the event of it being desirable to form the combined rocker and switch blade from sheet metal which is substantially rigid and unyield-l ing, this may be accomplished without sacrincing any of the desirable attributes of the construction just described by providing a spring element 32a, corresponding in purpose to the spring element 82 of the form of invention disclosed in Figure 3.K This spring element in this instance maybe pro- 26 vided with an enlarged circular aperture 38a of a diameter slightly in excess of the heighth of the trunnion 8a, to loosely receive the same so as not to be rocked lwith the oscillations of the rocker. In this instance, the ends 35a of the ilat spring 25 element are bowed outwardly toward a side wall of the casing to engage the same and to cause the entire rocker with its integral switch blade 28a to be normally urged toward the wall of the casing having the stationary contacts. The operation of 3o this modiiied construction of the device is in general the same as that device described in connection with Figure 1.

In the event that it is not desired to form the elevated portions of the side wall Il integral 35 therewith, asin the preceding modifications, they may be formed as separate pieces of nat insulating material 2lb and 22D, Figure 10, slid into grooves 38 provided in the side wall Hb at opposite ends thereof and an opening out through the 40 terminal seats, as shown. The piece 2lb, as shown, is provided with a laterally extending portion which is adapted to abut the shoulder 39 beneath the terminal seat to limit the downward movement and to space the lower edge of the in- 5 sulating piece in the bottom of the casing to provide a. recess 23 for the stationary lower contact I1. The insulating piece 22h extends all the way down to theA bottom of the casing, as shown, and its upper edge is substantially flush with the terminal seat. 'I'he upper edge of the lateral projection on the piece 2lb, likewise is iiush with its terminal seat, so that when the terminals are assembled with the casing, they eifectively retain the insulating pieces in proper position. The arrangement ofthe stationary contacts with respect to these insulating pieces may be the same as disclosed in conjunction withthe preceding forms of the invention.

In Figure 9, a modication of the side wall construction is disclosed in which the entire surface of this wall with which the contact blade is normally engaged, is capped or surfaced with a at piece of insulating material 40 shaped, with its two ends received in grooves, such as shown in c5 ,side walls lic to register therewith and if desired, these V-shaped edges of the notch Il may be spaced slightly above the corresponding portions of the recesses in the casing 5, so as to form the sole supportl of the rocker without assistance from the side walls of the casing. Any of the switch blades heretofore described may be used in connection with the construction shown in Figure 9, but preferably a blade such as shown in Figure 8 is used and which has its ends 30h offset as at I2.

From the foregoing it will be apparent that any suitable construction may be provided for the operating mechanism for carrying out of the various functions in the modifications as hereinbefore disclosed. It is also to be understood that various changes in the construction and arrangement of the other parts of the device may be resorted to without departing from the scope of the appended claims.

I claim:

1. In a snap switch, a support having a wall, stationary contacts, an actuating mechanism, a switch blade operated thereby and arranged with its ends urged toward said wall, and reversely arranged inclined blade engaging pieces positioned adjacent said contacts and inclined in progressively increasing degrees toward said contacts.

2. In a snap switch, a support, a pair of stationary contacts carried by a Wall thereof, an actuating mechanism including a rocker and an oscillatory switch blade operable by said rocker, and a spring blade structurally separate from the switch blade mounted upon said rocker and having deflected ends engaging the switch blade adjacent its ends to normally urge the same into engagement with said wall of the support, the wall serving to guide the switch blade ends toward and away from the-contacts.

3. In a snap switch, a support, a pair of stationary contacts carried thereby, an actuating mechanism including a rocker having an axially extending arm, a switch blade mounted on said arm and extending transversely thereof for cooperation with said contacts, and a resilient member structurally separate from said blade en'- gaging said rocker for normally urging the same axially and the switch blade toward the contacts.

4. In a snap switch, a support, a pair of stationary contacts carried thereby, an actuating mechanism including a rocker having a lateral arm provided with a shoulder, a switch blade mounted on said arm for cooperation with said contacts, and a ilat spring structurally separate from the switch blade engaging the shoulder to normally urge the blade in the direction of the axis of the rocker and toward the contacts.

5. In a snap switch, a support, a pair of stationary contacts carried thereby, an actuating mechanism including a rocker having a lateral arm provided with a shoulder, a switch blade mounted on said arm for cooperation with said contacts, and a spring blade structurally separate from the switch blade mounted upon said rocker in engagement with said shoulder and having deflected ends engaging the switch blade adiacent its ends to normally urge the same in the direction of the axis of the rocker and toward the contacts.

6. In' a snap switch. a support having opposing walls, contacts carried by one ot said walls, a substantially U-shaped rocker having fiat trunnion portions engaging the support, snap actuating means for said rocker, a transversely extending switch blade on one end of the rocker adjacent said contacts, means for yieldingly urging the blade ends `upon said contacts when in engagement therewith with a consequent axial thrust reaction upon the rocker, the trunnion opposite the blade end of the rocker having a substantially pointed end where it engages the support.

7. In a snap switch, a support having a cavity therein bounded laterally by substantially paral- 5 lel walls, bearing recesses formed in said walls, a substantially U-shaped rocker mounted in said cavity, said rocker having trunnions engaged in said recesses, snap actuating means for said rocker, a transversely extending switch blade on the 1o rocker adjacent one of said walls, contacts on said one of said walls for engagement by the blade, means for yieldingly urging the blade ends upon said contacts when in engagement therewith with a consequent axial thrust reaction upon l5 the rocker, the trunnion opposite the blade end of the rocker having its end reduced in crosssectional area and the recess opposite the blade end of the rocker having a thrust opposing bounding wall adapted to be engaged by the reduced 20 end of the trunnion.

8. In a snap switch, a support having a cavity therein, a substantially U-shaped rocker mounted in said cavity, snap actuating means for said rocker, said cavity having a bounding wall sub- 25 stantially normal to the axis of said rocker, a transversely extending switch blade on the rocker adjacent said wall, a spring member interposed between said rocker and said blade, and contacts on said wall for engagement by the blade 30 ends, the blade ends being yieldably urged toward said wall by said spring member.

9. In a snap switch, a support having a wall,

a switch blade-adjacent said wall and oscillatable on an axis substantially perpendicular to said 36 wall, means urging said blade toward said wall, stationary contacts outstanding on said wall i'or engagement by the ends oi said blade, and means associated with said wall to lift the blade ends to the contact surfaces as they approach the 4o contacts.

10. In a snap switch, a supp'ort providing a wall having an inclined surface, a contact carried by said support, an oscillatory switch blade adapted to engage said contact, snap actuating means 45 for said blade, and means normally axially urging said blade toward said inclined surface, saidA inclined surface serving to lift said blade to the contact surface of said contact.

11. In a snap switch, a support, a pair of stationary contacts carried thereby, actuating mechanism including a rocker having an axially extending arm provided with a shoulder, a resilient switch blade disposed between said shoulder and contacts, said blade having en d contact portions and a central portion fitted on said arm and abutting said shoulder, said central portion being offset toward said shoulder, there being cooperating portions between said rocker and support to take the thrust of the blade transmitted through said shoulder when said contact portions engage said contacts.

12. In a snap switch, a body, stationary contacts on a face presented by said body, a rocker mounted in connection with said body, snap actu-.65 ating means for said rocker, a switch blade carried by said rocker and having contact portions for cooperation with said contacts, and insulating portions disposed adjacent said contacts and upon which said contact portions ride to be guided onto said contacts, said insulating portionsbeingsoarrangedastoretardtheapproach of said contact portions to said contacts.

WILLIAM L. BUTLER.. 76

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