US1702220A - Electric switch - Google Patents

Description

Feb. 12, 1929. 1,702,220

A. H. NERO ELECTRIC SWITCH Filed May 1 4 INVENTOR RV/0 NERO Patented Feb. 12, 1929.

UNITED STATES 1,702,220 PATENT OFFICE.

ARVID H. NERO, OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO THE ARROW ELEC- TRIC COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

ELECTRIC SWITCH.

Application filed May 1, 1924. Serial No. 710,338.

My invention relates to electric switches, and particularly to a'push bar switch, the object of my invention being to provide a simple snap switch mechanism which is not only inexpensive to manufacture, but also eiiicient in operation.

In the accompanying drawings- Fig. 1 is a side elevation partially in section of the body of an electric lamp socket having a switch mechanism in which the invention is embodied inone form;

Fig. 2 is a plan view thereof;

Fig. 8 is a section on the line 3--3, Fig. 1;

Fig. 4 is a vertical transverse section through the switch body;

Fig. 5 is a similar view showing the switch mechanism in a different position;

Figs. 6 and 7 are perspective views of detaills of the construction drawn to a larger sca c.

It will be understood that the switch mechanism may be made of any desired size and capacity, and may be installed in fittings of various types, and that its illustration in a lamp socket merely illustrates a fitting of one type to which the invention is readily applicable.

The insulating body of the socket here shown comprises an insulating button 15, which may be of porcelain, and a cooperating insulating washer 16 of fiber or the like. The usual screw shell socket contact 17 rests upon the washer 16, while the center contact 18 is secured to the washer and constitutes a portion of the washer assembly unit. As will be clear from Figs. 4, 5 and 6, the center contact is secured to the washer by means of lugs l96ilsetfrom the base of the center contact, and passed through appropriate openings 20 therein, the ends of the lugs being clinched against the opposite face of the washer to rivet the contact thereto. The base of the contact is extended at 21 and the end thereof offset to form a switch terminal 22 which passes through another opening 23 in the washer into position for engagement by the switch plate hereinafter described. The holes 24 in the washer accommodate the two screw bolts 25 which pass through the button 15 and the washer 16 and take into the yoke 26 which overlies the base flange 27 of the screw shell 17, and serve not only to hold the screw shell in position but also to retain the Washer and other parts in assembled relation.

The binding terminals 28 and 29 are accommodated in wiring channels 30 and 31, formed in the opposite sides of the button 15. The terminal 28 is integral with the yoke 26 and thus forms a direct connection with the screw shell contact 17. The base strap of the terminal 29 is extended to form the second switch terminal 32, from which is oiiset an anchor flange 33. The latter is apertured to fit over a hollow boss 34 upstanding from the ledge on which the anchor flange rests, and against which it is held, in the assembled position of the parts, by the washer 16. As will be noted from Figs. 1 and 3, one of the screw bolts 25 passes through the boss 34 so that the Washer 16 is held firmly against the anchor flange 33 at this point, and thus secures the binding terminal 29 and the integral switch terminal 32 rigidly in position. When the parts are assembled the washer 16 is so located that the switch terminal 22 of the center contact 18 lies in the same plane as switch terminal flange 32 of the binding terminal 29, and both switch terminals rest against the side wall 35 of the switch chamber 36 formed in the button 15.

To make and break connection between the switch terminals 22 and 32 I provide a commutator 37 of the form shown on a larger scale in Fig. 7. This commutator 37 may be struck from sheet metal, and is of generally V-shape, the arms 38 and 39 thereof affording a relatively deep channel 40 therebetween. Projecting in opposite direction is a tail piece or stem 41 adapted to enter the axis of a coiled switch spring 42, which abuts at one end against the shoulders 43 at op osite sides of the tail 41. The switch cham er 36 is downwardly extended by a well 44, in which the spring 42 is accommodated, and against the bottom of which the opposite end of the spring rests.

To actuate the commutator I provide a push bar 45 having at its opposite ends insulating buttons 46. The push bar, also struck from sheet metal, is guided for rectilinear movement in narrow channels 47 formed in the button 15 on opposite sides of the switch chamber 36, and extending in a plane at right angles to the plane of the switch terminals 2232 and passing inter mediate the latter through the wall 35, against which they rest. The channels 47 lead to bays 48, in which the push buttons 46 are accommodated and against the bottoms of which the push buttons impinge to limit the movement of the push bar. Intermediate its ends, one margin of the push bar is shaped to form a cam 49 havin opposite inclines. The other margin of the bar is cut away to form a. pair of lugs 50 which bear against the inner face of the washer 16. In assembled position the cam margin of the bar 45 enters the channel 40 of the switch plate 37 and depresses the latter against the spring 42, which is thus under constant stress. The upward thrust of the spring forces the lugs 50 of the push bar against the inner face of the washer 16, which thus cooperates with the channels 47 in guiding the push bar for rectilinear movement.

The operation of the switch is readily understood. Upon the rectilinear displacement of the push bar 45, its cam 49 bodily displaces the switch plate 37 substantially in its own plane, and thus further stresses the spring 42. As the peak of the cam 49 passes the plane of the switch member 37 the effort exerted by the spring 42 causes the switch member to rise, while the opposite incline of the cam against which the plate is pressed by the spring causes the plate to swing away from the contacts 22-32with snap action. It is halted by its impingement against the opposite side of the switch chamber 36 in open circuit position. A. displacement of the push plate in opposite direction repeats the action and shifts the plate again to circuit-closing position.

It will be noted that the spring 42 flexes, as well as expands, so that its mean axis rocks across the chamber 36 with the throw of the switch late and the sides of the well 44 are flared or this purpose, while the bottom of the well is of such restricted dimensions as to confine the lower end of the spring against slip. The flare of the well may be dispensed with if a locating boss or recess beformed in the bottom of the well, to engage the end of the spring and thus hold it against slip, provided suflicient space between the walls of the well is provided to permit the body of the spring to flex.

The bodily displacement of the switch plate during the initial and final movements of the push bar causes a wiping contact of the switch plate with the switch terminals, and thus maintains the engaging surfaces clean and in condition to afford good electrical connection.

It will further be noted that the switch plate is held in position and guided partly by the spring and partly by the engagement of the push bar in the channel 40, while any tendency to twist out of its plane at right angles to the plane of the push bar is rectified by its impingement against the switch termmals at one side of the chamber and against the wall at the opposite side of the chamber.

It may also be pointed out that both the switch plate and push bar are in effect supported by the spring and float on that support, and that the push bar is restrained against escape, under the elfort of the spring, by the washer 16, which retains the push bar and thus the switch plate in position with the spring under stress.

The push bar 45, switch plate 37, wire and switch terminals, center contact and screw shell yoke may all be readily formed from' sheet metal, and are thus inexpensive to manufacture. The assembly of the parts is extremely simple and is readily accomplished by unskilled labor, without danger of.m1splacement of parts.

While the present switch mechanism may be used to advantage in various types of fittings, it is of particular value in fittings such as electric lamp sockets, where only a small.

space is available for the switch mechanism, since a wide quick break between the switch terminals and the switch plate may be obtained.

Various modifications in detailof form and construction will readily occur to those dealing with the problem, which do not depart, however, from the underlying thoughts which I claim as my invention.

I claim 1. In an electric switch, a base, a coil spring abutting at one end against the base, a floating switch bar supported by the opposite end of the spring, a reciprocating actuator and a cam thereon engaging the switch bar and shaped to cause the latter to successively stress and transversely flex the spring on the throw of the switch bar.

2. In an electric switch, a base shaped to afford a switch chamber, a guideway opening thereto, and a well at the bottom of the switch chamber, switch contacts arranged in the switch chamber on opposite sides of said guideway and having contact faces lying in a plane substantially normal to said guide way, a reciprocating actuator working back and forth in said guideway and having a peaked cam faced toward said well, a 'V-shaped switch bar riding said cam and having a throw across the switch chamber, a spring seated in said well and thrusting against said switch bar to stress the latter against the cam, and abutment means against which the actuator is thrust in sliding engagement by the efiort of the spring.

3. In an electric switch, an insulating body comprising a button of insulating material recessed to aflord a switch chamber and a guide slot opening to opposite sides thereof, and insulating sheet material resting 011 said button and forming a closure wall for said switch chamber and guide slot, wire terminals at opposite sides of the switch chamber, one of said terminals comprising a switch contact lying against a wall of said rocating push bar havinga peak cam engaged by said switch bar and serving, upon displacement of said push bar, to cause the throw of the push bar across the chamber under the stress of said spring, said push bar being constantly stressed against said sheet material closure wall by the effort of said spring.

4. In an electric switch, an insulating body comprising a button of insulating material recessed to afford a switch chamber and a guide slot opening to opposite sides thereof, and insulating sheet inaterial resting on said button and forming a closure wall for said switch chamber and guide slot, wire terminals at opposite sides of the switch chamber, one of said terminals comprising a switch contact lying against a wall of said chamber and to one side of said slot, a second switch contact carried by said insulating sheet material and lying against said wall on the opposite side of said slot, a coil spring seated at one end against the bottom of said chamher, a floating switch bar supported by said spring at its opposite end, and a reciprocating push bar having a peak cam engaged by said switch bar and serving, upon displacement of said push bar, to cause the throw of the push bar across the chamber under the stress of said spring, said push bar being constantly stressed against said sheet material closure wall by the effort of said spring.

5. In an electric switch, an insulating button recessed from one face to form a switch chamber with opposite walls and guideways opening through said walls, an insulating disc of sheet material arranged against one end of said button and forming a closure for the switch chamber and guideways, in combination with a spring-pressed switch and a reciprocating actuator arranged in said guideways and confined therein by said disc,- said actuator comprising lugs extending between the bottoms of the guidewa s and the disc, and spaced apart by a peak cam area adapted to play across the switch chamber on the displacement of the actuator.

6. In an electric switch, an insulating button recessed from one face to form a switch chamber with o posite walls and i'deways opening throng said walls, an insulating disc arranged against one end of said button and forming a closure for the switch chamber and guideways, in combination with a reci rocating actuator arranged in said gui eways and confined therein by said disc, said actuator comprising lugs extending be tween the bottoms of the guideways and the disc, and spaced apart by a. peaked cam area adapted to play across the switch chamber on the displacement of the actuator, together with a switch plate riding said cam and playing between said opposite walls of the switch chamber, and spring means tending constantly to hold said switch plate against the cam.

7. In an electric switch, an insulating body shaped to afford a switch chamber having opposite walls, a pair of spaced switch contacts facing one of said walls, an actuator guided for rectilinear movement across said chamber between said contacts and having a peaked cam, a switch piece riding said cam,

a compression spring stressing said switch piece against said cam to cause the switch piece to move across the chamber with snap action in opposition to the direction of movementof the actuator on rectilinear displacement of the latter, in combinationwith an insulating disc of sheet material forming a closure for the switch chamber, and against which said actuator is thrust by the stress .of

the switch spring.

In testimony. whereof I have signed my name to this specification.

Anvil) H. NERO.-

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