US2095175A - Electric switch construction - Google Patents

Description

Oct. 5, 1937. H. A. DOUGLAS 2,095,175

ELECTRIC SWITCH CONS IRUCTION Original Filed May 31, .1934

HARRY A. DOUGLAS 8) K ATTK ramsaocssmsz UNITED STATES PATENT OFFICE v 3,09 ,175 v ELECTRIC SWITCH CONSTRUCTION new a. mum, Bronson, Hlcla, allsncr to 1: 1am Products a corporation DM May 81, 1934, Serial No. 728,278

r May 15, 1036 can. (ciao-cs) tached to a support therefor, such as, an escutch-' an plate or instrument board, as the case may With these and other objects in view, reference is made to the accompanying sheet of drawings which illustrate a preferred embodiment of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

In the draWing- Figure 1 is a view in central vertical section of an embodiment of this invention, with parts ill go trated in elevation.

Flsure2isaviewin-sectiontakenontheline 2-4, Figure '1.

Figure 3 is a view insection taken on the line 3-3, Figure 1.

35 Figure 41s adetail view insection taken on 85 breaking upon the closing of the circuit. As illustrated inl'lgures 1, 2 and 3, the switching mechanism is enclosed in a cup-shaped metonic-cylindrical casing I having the bottom or 40 end closure 2 provided with a central circular opening for the reception of a shoulderedvmetallicsleeveltheinner endofwhichisspunover or riveted p n the inner side of the closure 2 to securethe sleeve thereto, as shown. The outer 4 exterior portion of the sleeve 3 is screw threaded for m1: 1 a locking nut I when mounted upon a support I therefor, which may be the cover or e'ccutcheon plate of a wall switch or the instrument board of an automotive vehicle, by passing the sleeve 3 through a circular opening provided in the support and applying the nut I on the exterior thereof to draw the closure 2 in clamped relationuponthebackof thesupportl. The interior surface O of the sleeve 3 is of spherical 65 formation for a p rp se hereinafter described,

Theopenendofthecasing I isclosedbya contactcarryingdisc'lofinsulatingmaterial which is held securely in position by a plurality of spaced apart iingers 8, preferably three in number, forming integral extensions of the casing 5 wall which are passed through corresponding notches 8 in the periphery of the disc I and then bent over the outer surface of the discio hold the same firmly a ainst the end'of the casing' wall. The contact carrying disc I mounts two 1 electric terminals I. and II, preferably of the snap terminal type disclosed inthis applicant's prior copending application, Serial Nm 713,713, filed March 2, 1934, adapted to be electrically connected to electric conductors, not shown, upon 15 the outer side of the disc 1. As shown-each terminal includes a rectangular block having a cylindrical extension which extensions are preferably reduced in diameter, as shown.- When this type terminal is employed, it is desirable to provide the carrier disc 1 with circular apertures through which the reduced extremities of the terminalsare passed and the metal of the end is then expanded or riveted upon the interiorof the disc I to hold the terminals in place. The terminals II and ii are mounted on perpendicularradiiofthedisclanequal distancefromthe center.

The center of the contact carrying disc I is provided with an integral rectangular projection of insulating material upon its inner'surfac'e havingsides l2 parallelto theradiithrough the terminals II and II with the edge adjacent terminal I I joinedto an upwardly extending angularsurface II terminatinginacentral transverse portion It. An electric contact II in the form of a metallic strip is connected to the terminal ll, preferably by passing the reduced .lindricalportionthereofthroughanaperture provided therefor in the end of saidstrip, upon 40 theoutersideofthecontactcarrying disc. The other end of the strip is then through thedisc 'I to embrace theadiaeent side and angular surface ll of the central projection uponthe opposite the contact strip II is continued downwardly therefrom at an angle similar to that formed by the upper surface of said strip for a similar distance andthencurvedupwardlyto form .a stop I, for a purpose hereinafter descdbedrflheexpandedorriv etedbeadofthe provided therefor upon the inner surface of the disc 7 to be wholly received below that surface, for a purpose hereinafter described.

The switching mechanism is carried upon a U- shaped metallic bracket having a rectangular base I! with a central cut out portion iii, to receive the projection of the disc I, providing end portions l9, one of which extends over the countersunk expanded end of the terminal in and having the sides of the base l1 provided with integral outstanding perforated ears 20 and 2!. The reduced cylindrical portion of the terminal ii is passed through the apertured ear 20 with the end expanded or riveted upon the upper surface thereof while the other ear 2| is secured to the disc l by a rivet 22 passing through the ear and disc with the metal of the ends expanded or riveted thereon. The inner side of the end portion 99 of the base extending over the terminal M3 is spaced from the contact l5 and the opposite end portion i9 is in engagement with the central projection of the disc I. The spaced apart end portion I9 is provided upon its inner side with integral upwardly extending stop 23 bent back at an angle and spaced apart from the con tact E5 to form a stop complementary to the stop 56 of the insulating projection.

The ear bearing sides of the base are extended upward to form two similar arms 23 perpendicular to the base E7 and equally spaced from the axis of thecasing l with each side of each arm provided midway its height with outstanding integral fingersZS. The switching device for alternately continuing the circuit from the terminal H to the contact i5 of the terminal i0 is mounted to oscillate upon a pivot 26 passing through apertures in the upper ends of the arms 23. The circuit making and breaking mecha nism includes an oscillating actuator caused to oscillate by a manually operable oscillating operator.

The actuator is mounted upon a pivot pin 26 passed through apertures in the arms 26 of the supporting bracket and includes two similar me-= tallic actuating plates 21 adapted to receive the pivot pin 25 and depend therefrom in sliding engagement with the respective arms 24! of the supporting bracket and terminating short of the high point of the carrier disc projection surface It with a portion of theopposite longitudinalsides struck up at right angles to the main body to form right angular flanges 28 extending upward from the bottom leaving oppositely disposed similar outstanding arms 29 extending from the body of the plate, the .longitudinal edges of the flanges 28 are adapted to engage the similar edges of the corresponding flanges on the respective plates 21. mounted upon the pivot pin 26in similar longitudinally elongated bearings 36 allowing a slidare provided with transverse flanges 32 adapted to pass under the lower extremities of the actuator flanges 28 with the terminations thereof inclined upwardly to engage the outer sides of the oppositely disposed actuator flanges on each side The actuator plates 21 are terminal I0 is preferably received in a recess of the housing and position the base or top of the housing at a distance below the lower end of the actuator bearing 36. The housing 31 receives in sliding engagement therewith a detent 33 in the form of a rectangular casing closed at the lower end in a rounded nose 34 and open at the other end to receive a coil spring 35 bearing against the interior of the nose and top of the housing. When the actuator and operator have been assembled upon the supporting bracket the fingers 25 of the bracket'arms 23 are bent toward each other, as shown in Figure 8, to prevent the nose 34 when mounted on the disc I from riding over either of the stops i6 or 23;

The actuator is caused to oscillate by the manual movement of an oscillating operator. The manually oscillated operator is formed of insulating material preferably a phenolic condensate such as bakelite" and is provided with a depending perforated portion 36 slidably received between the actuator plates 27 to receive the pivot pin 26 and mount the operator for oscillation thereabout. The upper portions of the actuator plates 21 are cut on the arc of a circle concentric with the pivot pin 26 when the upper bearing surface thereof is in engagement with the upper side of said pin. The depending portion 36 of the operator is extended beyond the actuator plate 21 on each side of the pivot and each side of said portion is provided with an annular outstanding fiange 31, the inner surface of which is concentric with the 'pivot pin 26 and of a radius sumcient to cause the flanges 31 to clear the top of the actuator plates 21 when the lower bearing surface thereof is in engagemenhwith the lower side of the pivot pin 26. The lateral extensions of the member 36 and flanges 3i thereon are terminated on each side of the pivot 26 in surfaces 38 curving slightly upward with the surfaces 38 of the flanges in contact with the actuator arms 29 when the lower end of the bearings 38 of the actuator are in engagement with the under side of the pivot' pin 26. The uppersides of theportion 36 and flanges 31 are of spherical formation following the surface of a sphere concentric with the longitudinal center of the pivot pin 26 and extending above the sleeve 3, as indicated at 39, which surface has a sliding contact'with the inner surface 6 of the said sleeve. An operating handle 60 for manual operation is formed integral with the portion-36 and projects from the surface 39 centrally thereof perpendicular to the plane of the surfaces 33' thereof.

Figures 1 and 2 illustrate the normal positions moved the actuator to slide over the pivot pin 26 to bring the lower end of the bearing 30 in resilient engagement with the under side of said pivot pin and the actuator arms 29 have engaged both stop surfaces 38 of the oscillating manual operatorand thecircuit is completed from terminal H to the terminal '50 through the bracket, the actuator and current continuing nose 34 to contact strip l5, but also is completed by the nose 34 acting as a current continuing bridge from the stop 23 of thebracket to the angular surface of it imparts a rotative movement to the operators and through contact of the engaged stop II with the adjacent actuator arm 2! to first bodily move the actuator in the direction of the engaged stop II of thebase I'l until the upperend of the bearing ll engages the upper side of the pin 28,

placing the detent spring 8! under greater ten-v As the rotative movement of sionthan normal. the operator continues, it. imparts av rotative movement to the actuator about its upper bearing on the pivot 28 causing the detent nose 34 to travel over the upwardly inclined surface of the contact I! towards its high point, as shown in Figure 5, holdingthe contact with the terminal I II closed under a slightly increasing tension of the spring I! as the nose approaches the high point of the contact II. During the rotative movement the pivot pin It acts as the fulcrum of a bell crank lever with power being applied upon one arm by, the operator handle at the point of contact P between the oscillating operator end ll, and the actuator arm 29. -,During this movement, the point of the contact P moves in the direction of the angular surface of the contact II so that as the line from vthe point P to the engaging'point of the nose )4 approaches a right angle to the angular surfaces of the contact II, the friction of the nose thereagainst is minimized. The movement of the-nose 34 toward the high point of the carrier projection increases the tension of the spring 35 so that just before the nose reaches the high point, the spring 35 bodily-moves the actuator away from the contact I! to bring the lower end of its bearing 30 into 'engagement with the under side of the pin 28 with the nose I still held in contact with the strip I5, and during this movement causes the actuator to rotate about the point P as a pivot. In other words, during the application of power at P; the bell crank lever rotates about the pivot 26 as a fulcrum, but as the nose-SI approaches the high point of the projection, power is applied at the lower end of the other arm of the bell crank lever causing it to rotate about the point P as a fulcrum, the elongated bearing 30 allowing sliding movement of the actuator about the fixed pivot 26. The movement imparted to the actuator 21 by the stored up power in the spring '3! causes the nose 34 to snap over the high point of the projection II and to quickly extend the nose 34 to engage the stop It on the other end of the.

insulating projection andthereby quickly oscillate the nose to break engagement with the contact terminal ID. i

From the above, it is seen that as soon as the handle ll has rotated the oscillating operator sufficiently to shift the actuator from its normal pivot- 28 to its eccentric pivot'P, the spring 35 automatically completes the oscillationto snap the nose 34 out of engagement with the contact strip I and thereby break the circuit from terminal II to terminal II. Upon depression of the handle I. from the upper lifted or rotated position, the action above described is reversed and the parts returned to theposition shown in Figure 1.

This invention also contemplates its applica-. tion to a two circuit switch, as shown in Figure 6.

r In this form the central insulating projection carrying the contact strip I! from the terminal II is provided with a complementary oppositely dispom surface Ila uponv which is mounted a opened alternately.

stop 28.

In this form, when the current continuing nose :4 is oscillated by the handle 40 to break the circuit to the terminal II just as soon as it is snapped over the flat insulating surface I4 it immediately emses the contact strip .I Ba to complete the circuit to the terminal Ila. and then slides over said contact strip until it engages the stop 23a upon the end portion IQ of the metallic bracket, whereby upon manual operation of the handle 40 the respective circuits from the terminal II to the terminals III and Ila are each closed and As shown and described the parts of this improved switching mechanism, excepting the manual operator and the contact carrying disc are all adapted to be formed of metal stampings to be easily and quickly assembled. The operating parts are dependable as the spring I! for imparting the snap movement is fully protected and the other parts are so constructed that the switch may bepperated thousands of times without any of the parts deteriorating or getting out of order.

,vided with an upwardly extending stop 23a bent back at an angle similar to the corresponding Certain features, common tothe present application and to applicant's Patent 2,044,065, June 16, 1936, are claimed in the aforesaid patent.

What I claim is:

1. An electric switch including a casing, a contactcarrier mounted thereon, and switching mechanism mountedon the carrier within the casing including a plurality of spaced apart electric terminals mounted on the carrier, said carrier provided with an axial projection of insulating material having spaced apart oppositely disposed angular surfaces extending downwardly from the top thereof, contact strips having one end inset upon an angular surface with its upper surface terminating flush with the top of the projection and having its other end connected to one of the terminals, a metallic bracket in electri- I cal engagement with another terminal surrounding said projection and spaced apart from said contacts with upstanding arms on each side of said projection, a circuit continuing bridge having a back and'forth movement over the angular surfaces of said contacts, stops to limit said travel after making or breaking the circuit from one terminal to the other, said bridge carried in an actuator mounted .for oscillation about a pivot mounted on said bracket arms, a manually operable oscillating operator mounted on the actuator pivot having means to engage and oscillate the actuator, said actuator having a sliding engagement with its pivot and sliding engagement with the bridge. means maintaining the actuator in engagement with its pivot and with said bridge in engagement with a contact, means extending through the casing to oscillate the operator to engage and slide the actuator bodily over its pivot and then rotate the actuator to travel in sliding enga m nt with the bridge, and means to shift thereafter snap the bridge to make or break the circuit.

2. An electrical switch including a cup shaped casing, a contact carrier mounted upon the open end thereof, and switching mechanism mounted upon the carrier within the casing including a central projection of insulating material upon the carrier having spaced apart oppositely disposed angular surfaces extending downwardly from the top thereof, a plurality of spaced apart electric terminals-mounted upon the carrier, a contact strip inset in an angular surface of the projection terminating at the top thereof and connected at the'other end to one of the terminals, a metallic bracket surrounding the carrier projection, spaced apart from the contact on said projection and connected to another terminal, said bracket having upstanding arms on each side of said projection, a circuit continuing bridge adapted to wipe over said angular contact and surface of the carrier projection to close and open a circuit from the bracket terminal to the other terminal, an actuator resiliently carrying the bridge for oscillating the bridge ovcrsaid projection including spaced apart plates mounted for oscillation upon a pivot between the arms of said bracket, '8. manually operable operator mounted upon the actuator pivot between the actuator plates and having a handle extending through the end closure of the casing, and means upon the operator to engage and oscillate the actuator .upon back and forth movement of the handle to oscillate the bridge.

3. The structure of claim 1 wherein the said actuator has a sliding engagement with its pivot and sliding engagement with the bridge with means maintaining the actuator in engagement withits pivot and with said bridge in engagement with said projection, said handle extending through the casing adapted to oscillate the operator to engage and move the actuator over its pivot and rotate the actuator causing the bridge to travel in sliding engagement over the angular contact on the projection, and means to shift the axis .of rotation of the actuator from its normal pivot to a pivotal point eccentric thereto and thereafter snap the bridge to break or make a circuit therethrough.

- 4. The structure of claim 2 wherein the bracket is provided with a stop to limit the travel of the bridge and maintain its engagement with a contact when so limited by astop, and wherein the said projection is provided with a stop to limit the travel of the bridge in the opposite direction and maintain it out f engagement with a contact when so'limited y the projection stop.

.5. An electric switch, comprising: a movable contact constructed and arranged to move from one limiting position to another limiting position through a central position; a stationary member having a surface slidably engaged by said movable contact; a stationary contact fixedly mounted on said stationary member and having a surface forming part of said stationary member surface, that portion of said stationary mem-' ber surface engaged by said movable contact when in its central position being of insulating material, said movable contact engaging said stationary contact when in one of said limiting positions; snap action means, for slidably moving said movable contact away from said one of its limiting positions; said snap action means including energy storing means and being so constructed and arranged that energy is first stored in said energy storing means and then, before said movable contact reaches said central positionthe stored energy is released to snap said movable contact off of said stationary contact onto said insulating portion.

6. An electric switch, comprising: a movable contact having a limiting position; a stationary member having a surface slidably engaged by said movable contact, said surface being inclined into the path of movement of said movable contact when said contact moves in a direction away from said limiting position; a stationary contact fixedly mounted on said member and, having a surface forming part of said inclinedtsurface, the

continuing portion of said inclined surface being of insulating material, said movable contact engaging said stationary contact when in said limiting position; snap action means, for slidably moving said movable contact from said position up said inclined surface, so constructed and arranged that before said movable contact reaches the upper end of said stationary contact said movable contact is caused to automatically snap off of said stationary contact onto said insulating portion of said inclined surface.

HARRY A. DOUGLAS.

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