US2832852A - Toggle switch - Google Patents

Description

April 29, 1.958 T. A. ANDREW TOGGLE SWITCH Filed Nov. 21. 1955 INVENTOR. Flo/m5 A. ANDREW TOGGLE SWITCH Thomas A. Andrew, Newport Beach, Calif., assigner to `l'anco Corporation, Burbank, Calif., .a corporation of California Application November 21, 1955, Serial No. 547,926

8 Claims. (Cl. 20G- 18) This invention relates to electrical control devices and dicator -light for indicating the condition of the con-l trolled mechanism. Generally, such switches comprise a pair of switch elements which are operated by the single operating lever. In order that the indicator light always accurately indicates the condition of the controlled mechanism, it is essential that these two switch elements, for controlling the mechanism and the light, be actuated substantially simultaneously. Moreover, to facilitate operation of the switch and assure proper positioning of its operating lever in either of its extreme positions, movement or deiiection of the lever between these extreme positions must be appreciable.

Switches for use in aircraft installations are subject to considerable shock and vibration during flight of the aircraft and, accordingly, it is essential to the reliability of the switches that they not be sensitive or responsive to such vibrations and'shock, that is, that their contacts will remain closed under the most adverse conditions of shock and vibration.

Accordingly, it may be stated as a primary object of this invention to provide a toggle switch, intended primarily though not exclusively for use in aircraft installation, which fulfills the above and other requirements.

Another object of the invention is the provision of a toggle switch embodying a pair of switch mechanisms which are substantially simultaneously actuated upon movement of the switch operatinglever between its extreme positions.

Yet another object of the invention is the provision of a toggle switch wherein the operating lever undergoes appreciable movement of deflection between its extreme positions so as to insure proper positioning of the lever.

A further object of the invention is the provision of a toggle switchwhose operation is substantially unaffected by an environment of shock or vibration in which the switch may be used.

And still a further object of the invention is the provision of a toggle switch whose operation involves a substantial mechanical advantage so that maximum contact opening and closing forces may be exerted with a minimum force on the operating lever.

The invention may be best understood from the following detailed description thereof taken in conjunction .wanted States atent O Fiice switch operating lever being omitted for the sake of clarity; and

Fig. 4 is a view similar to Fig. 1 with the switch operat` ing lever shown in its other extreme position.

Referring now to these drawings, the toggle switch of this invention comprises a hollow metallic casing 10 open at its upper end, two opposite side walls of which casing are formed with rectangular tabs 11 that are bent inwardly at right angles to the planes of the side walls and have their inner'edges spaced as shown in Fig. l. Closing the upper end of the casing 10 is a cover plate 12 formed with a central rectangular opening 13 and iixed in position as by being bolted to the tabs 11, as indicated at 14. Secured to the underside of this cover plate 12, in the space between the inner edges of tabs 11, are a pair of plates 15 and 16 which are centrally formed with alined slots 17 and 1S registered with the opening i3 in the cover plate 12. The upper one 15' of the slotted plates has formed on its upper surface a rectangular raised portion 19 of a sizek and shape corresponding to and received within the opening 13 in the cover plate l2. The plates 15 and 16 are secured in position as by rivets 20.

The opposite end walls of the slots 17 and 18 in the plates 15 and 16 conform to segments of a circle as shown, and received in these slots is a generally diskshaped intermediate portion 21 of an operating lever 22. The arrangement is such that lever 22 is pivotally mounted in the plates 15 and 16v for pivotal movement between the position it occupies in Fig. l and the position it occupies in Fig. 4.

Encircling a lower cylindrical portion 23 of lever 22 is a compression spring 24 which bears at its upper end against an annular shoulder 25, adjacent the juncture of the cylindrical portion 23 and the disk-shaped portion 2i, and at its lower end against a sleeve 26 slidable on the lower end of the cylindrical portion 23. Sleeve 26 is retained for limited axial sliding movementon the cylindrical portion 23 by pin and slot arrangement 2'7 and, has its lower end transversely slotted as shown at 2S. The furcations 29 defining therebetween the slot 28 have their lower edges rounded, as illustrated, and journaled on a pin 30 fixed at opposite ends in the furcations 29 is a roller 3l the lower portion of whose periphery projects somewhat beyond the curved end portions of the furcations.

Roller 3l bears on and is adapted to ride over a curved platen 32 of a rocker 33. Rocker 33 further comprises a pair of flanges 34 which extend downwardly from the side edges of platen 32 at an intermediate portion of the latter, these flanges straddling and slidably bearing against the outer side surfaces of a pair of generally triangular-shaped flanges 35 on a bracket 36 xed by rivets 37 to the bottom wall of casing lli. A pivot pin 33 extends through flanges 34 and 55 and has its opposite ends shouldered, as indicated, for pivotally mounting the rocker 33 on the bracket 36.

From the description thus far it will be seen that roller 31 is resiliently urged into contact with the curved platen 32 by the compression spring 24 and that said roller may be caused to move from one end of the platen to the other end thereof by pivotal movement of the operating lever between the positions of Figs. l and 4. It will be further apparent that so long as a roller 31 `bears on that halt of the platen 32 to the left, as viewed in Fig, l, of a dead center line extending through the pivotal axes of the rocker 33 and the operating lever 22, compression spring 24 will act to maintain the rocker 33 in its pivotal position illustrated in Fig. l. Simultaneously with the movement of the roller 3l across that dead center line, by left hand movement of the operating lever from 4l) will be retained closed.

the positiony in Fig. lto that of Fig. 4, the rocker 33 ywill be snapped to its right hand pivotal position, illustrated in Fig. 4, by the action of the biasing spring 24.

This pivotal movement of therocker`33isarranged tooperate a pair of microswitches 39 and 40 in thefollowing-manner.

Each of the microswitches 39 and 40 comprises an actuating arm. 41v whose upper. end is pivoted at 42 to the casing of its associated microswitch and which is biased awayfromr its casing to normal position by springs, not shown. These actuating arms 41 bear, at an intermediate point, against the outer ends of the operating plungers 43 of the respective microswitches so that the microswitches 39 and 40 will be opened and closed by movement of the pivotal arms 41 toward and away from their respective microswitches, The lower extremities of the actuating arms 41 are narrowed as indicated at 44, Fig. 2, are bent to a generally flat-bottom V configuration 45 with the flat bottoms 46 of the v-shaped portions being disposed in substantially parallel planes in position to intersect, at substantially right angles, a line extending through the pivotal axis of the rocker normal to said dead center line extending through the pivotal axes of the rocker and actuating lever 22. Ex-

tending from opposite sides of the flanges 34 of the rocker 33 are a pair of pins 47Y each of which extends axially to a position of juxtaposition of its free end portion with the V portions 45 of the arms 41. The arrangement of these pins on the rocker 33 is such that when the latter is in its left hand pivotal position, illustrated in Fig. 1, the left hand one of the pins 47, as viewed in this figure, will have its center on the aforesaid line tending through the rocker pivotal axis normal to the iiattened portion 46 of its respective operating arm 41 and will bear against said flattened portion in a manner to maintain the corresponding operating arm 41 depressed out of its normal position so that, for example, if microswitch 40 is a normally open switch, it will be in its closed condition when the rocker is in the position of Fig. l. The right hand one of the pins 47, as viewed in Fig. l, will, however, be disposed above said normal line extending through the rocker pivotal axis and in the vicinity of the upper sloping sides of the V of its respective operating arm 41 so that the latter will be cleared to be retained in its normal position by its biasing spring.

Upon the aforedescribed left hand pivotal movement of L the operating lever 22 from its position of Fig. l to its position of Fig. 4 to rock the rocker 33 to its right hand pivotal position illustrated in Fig. 4, the right hand one of the pins 47 will ride into the flat bottom portion 46 of its associated switch operating arm 41 to cam that switch operating arm out of its normal position'l Simultaneously, the left hand one of the pins 47, as viewed in the drawings, will be moved to a position corresponding to that occupied by the right hand pin 47 in Fig. l so that the switch operating arm 41 associated with the left hand one of the pins 47 will be permitted to return to its normal position under the action of its biasing spring. Thus, assuming both switches to be normally open switches, switch 39 will, in the position of the operating lever shown in Fig. l, be open while switch Upon movement of the operating arm 22 to the position of Fig. 4, the rocker 33 will bey snapped from its left hand pivotal position, shown in Fig. l, to its right hand pivotal position, shown in Fig. 4, to substantially simultaneously effect the closing of switch 39 and reopening of switch 40.

Each of the switches 39 and 4t) may include a plurality of terminals 48 for connection to the lead in the electrical circuit which they are to control. Thus, switch 39 may be connected in a circuit, not shown, extending to a motor to be selectively operated, while switch 40 may be connected in an energizing circuit, not shown, for an indicator light for indicating whether the motor control circuit' is' energized ror deenergized.

4 Fromtheforegoing. description. it willv be. apparent that the present switching arrangement provides for optimum reliability even under relatively severe conditions of shock and vibration, as are found, for example, in aircraft installations, inasmuch as appreciable deflection of the operating lever 22 is required to operate the rocker from one of its pivotal positions to its other pivotal position so that even substantial movement of the operating lever as the result of such vibrations and shocks will not .produce accidental actuation of the switch. This inse Ynears or non-responsiveness of the present switching arrangement to an environment of shock or vibration is also aided by the on-center locking feature of the rocker 33 and its pins 47. Thus, with the parts positioned as shown in Fig. 1, switch operating arm 41 ot' switch 4t) will be locked out of its normal position when the corresponding pin 47 of the rocker is in oncenter relationship with respect to the rocker pivotal axis, that is, when the center of said pin 47 is on the aforesaid line extendingY through the rocker pivotal axis normal to the flat' portion 46 of its respective switch arm 4l. Thus, for a limited angle of pivotall movement of the rocker, movement of the left hand pin 47 will be substantially normal to the direction of pivotal movement of its switch armr 41 andv substantially parallel to the plane of the associated flat portion 46, and, accordingly, the corresponding switch operating arm 41 will be retained out of its normal position even during any slight pivotal movement of the rocker as a result of the switching mechanism being subjected to vibrations and shocks. Shocks and vibrationswill not, therefore, result in fluctuating of the switch contacts. It will be seen that the length of the platen 32, over which the roller 31 moves between extreme positions of the operating lever 22, accommodates appreciable movement of the operating lever which is desirable for ease of operation and proper positioning of the lever. Moreover, the arcuate configuration of the platen 32 provides a' mechanical advantage, which, for example, may be made less by causing the platen32 to conform more to a flat plane. This mechanical .advantage enables maximum closing forces to be exerted on switch operating arms 41 with a minimum force applied to the operating lever 2.2. Due to the snap action of the rocker 33 upon movement of the roller 31 past the dead center position during movement of theV operating lever 22 between its extreme positions, substantially simultaneous operation of the switches 39 and 40 is eected so that, for example, where one switch controls the operation of a controlled mechanism and the other switch controls the energization of an indicator light, the latter will always accurately indicate the condition of operation of the controlled mechanism. The present switchingV arrangement renders it virtuallyv impossibleto accidentally position the operating lever 22 in a central or neutral. position wherein both of the switches 39 and 40 would` be inthe same condition.

From the foregoing description itv will be seen that there has been described and illustrated a toggle switch which is fully capable of attaining the objects and advantages heretofore set forth. While a preferred. embodiment of the invention has been illustrated and dcscribed, it will be apparent to those skilledf in. the art that numerous modifications in designV and arrangement of parts is possible within the scope of the following claims.

I claim:

l. An electric switch, comprising: a support, a rocker pivotally mounted on said support, switch means mounted on said support and including a pivotal actuating arm swingable about an axis spaced from and substantially paralleling the pivotal axis of the rocker, said arm extending toward the latter axis and `being formed with a relativelyrshort, straight section extending substantially parallel to a iirst imaginary plane passing ,5 through said axes and extending to opposite sides of a second imaginary plane passing through said rocker pivotal axes normal to said first plane, an actuating-armengaging element on said rocker rotatable into said second plane and engageable with said straight section of the actuating arm when the rocker is rocked in one direction for retaining said arm in one operative position, said element being movable beyond one end of said section when the rocker is rocked in the opposite direction, the portion of said arm adjacent said one end of the section being relieved to accommodate swinging of said arm in theA direction of said element to a second operative position when said element is located beyond said one end of the section, said switch means including yieldable means biasing said arm in said latter direction, and handle means engageable with said rocker for rocking the latter in opposite directions.

2. The subject matter of claim 1 wherein said straight section is olset toward said element in substantially spaced parallel relationship to the remainder of the arm, and said arm is formed with an inclined section at said one end of the straight section forming a cam surface engageable Iby said element upon rocking of the rocker in said one direction for camming said arm to said one operative position.

3. The subject matter of claim 2 wherein said arm comprises a flat strip which is bent to form said inclined and straight arm sections.

4. The subject matter of claim 1 wherein said element comprises a pin on said rocker spaced from and extending substantially parallel to the rocker pivotal axis, said straight section extending between said latter axis and said pin, and the portion of the arm adjacent said one end of the straight section being inclined toward said first plane to afford relief in the arm to accommodate swinging of the latter in said direction toward said element under the action of said yieldable means.

5. The subject matter of claim 1 wherein said rocker comprises an elongate platen extending to opposite sides of the rocker pivotal axis and having a generally cylindric surface extending to opposite ends of the platen and substantially paralleling the latter axis, and said handle means comprises an elongate handle member pivotally mounted intermediate its ends on said support and including a yieldable element at one end engaging said cylindric surface and movable between opposite ends of the platen by swinging of the handle to rock said rocker in opposite directions.

6. An electric switch, comprising: a support, a rocker pivotally mounted on said support, a pair of switch means mounted on said support and each including a pivotal actuating arm swingable about an axis spaced from and substantially paralleling the pivotal axis of the rocker, each of said arms extending toward the latter axis and being formed with a relatively short, straight section extending substantially parallel to a first imaginary plane passing through the latter axis and the pivotal axis of its respective actuating arm and extending to opposite sides of a second imaginary plane passing through the rocker pivotal axis normal to the respective first plane, a pair of actuating-arm-engaging elements on said rocker, one of said elements being rotatable into one of said second planes and engageable with one of said straight sections when the rocker is rocked in one direction, and the other element being rotatable into the other second plane and engageable with the other straight section when the rocker is rocked in the opposite direction for retaining the respective actuating arms in one operative position, said elements being movable beyond one end of their respective straight sections when the rocker is rocked in the opposite directions, the portions of the respective arms adjacent Vsaid one end of said one straight section being relieved to accommodate swinging of the arms toward their respective elements to second operative positions when said elements are located beyond said one end of their'respective straight sections, each of said switch means including yieldable means biasing its actuating arm toward its respective element, and handle means for rocking said rocker in opposite directions.

7. The subject matter of claim 6 wherein said elements comprise a pair of pins on said rocker spaced from and extending substantially parallel to the rocker pivotal axis, the portions of said actuating arms adjacent said one end of the straight section being inclined away from the respective pins and forming camming surfaces engageable by the pins for camming the arms toward their respective one operative position when the rocker is rocked.

8. The subject matter of claim 7 wherein said straight section of each actuating arm extends between the adjacent pin and the pivotal axis of the rocker, said inclined portion of each arm inclining toward the respective rst plane.

References Cited inthe tile of this patent UNITED STATES PATENTS 2,267,203 'Krieger Dec. 23, 1941 2,369,964 Go Feb. 20, 1945 FOREIGN PATENTS 723,704 Great Britain Feb. 9, 1955

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