US2190525A - Electric switch - Google Patents

Description

Feb. 13, 1940. F. H. TRAVERS ELECTRIC SWITCH Filed Jan. 29, 1937 Inventor-z Fred H.Tr-aver's,

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Patented Feb. 13, 1940 1 PATENT OFFICE ELECTRIC SWITCH Fred yH. Travers, Stratford, Conn., aasignork to General Electric Company, New York, N. Y.

Application January 29, 1937, Serial No. 123,036

3 Claims.

My invention relates to electric switches and more particularly to a multi-position tumbler type electric switch.

An object of my invention is to provide an 5 electric switch of the tumbler type which is positive in action and may be used to control any number of circuits desired and may be used to provide any number of operating positions desired.

Another object of my invention is to provide an improved electric switch that is sturdy in construction and has a minimum number of parts which may be manufactured at a low cost and readily assembled. 15 What I consider to be novel and my invention will be better understood by reference to the following specification and appended claims when considered in connection with the accompanying drawing, in which Fig.l 1 is a perspective view of the assembled switch; Fig. 2 is a side sectional View, and Fig. 3 is a perspective view in part of the operating mechanism.

Referring to the drawing, I indicates a base of insulating material. Secured to the base I0 are a plurality of stationary contacts, two of which, indicated by numerals II and I2, may be seen in Fig. 1. Cooperating with stationary contacts II and I2 are movable contacts I3 and |4 carried respectively by leaf springs I5 and |6 which are secured at their opposite ends to base I0. For moving the movable contacts into engagement selectively with the stationary contacts, a cam Il is provided and positioned between springs I5 and I6. In the position in which cam il is located in Fig. 1 the movable contacts I3 and I4 are out of engagement with the stationary contacts and I2. When cam I 'I is rotated in a clockwise direction it engages spring I5 moving contact I3 into engagement with contact II. As the spring 5 is iiexed by cam I'I after contact I3 engages contact I| there is a relative transverse movement between the contacts II and I3 producing a wiping action. This wiping action tends to keep the contact surfaces bright. Similarly when cam Il is rotated in a counter-clockwise direction from the position of Fig. 1 spring I6 is engaged and contact I4 is moved into engagement with stationary contact I2. When a circuit is opened by the sepai0 ration of two contacts an arc is drawn between the contacts which increases in length and the amount of energy it absorbs with the distance the two contacts are separated. Therefore, to

limit the distance of separation of the stationary ;5 and movable contacts when the circuit is opened (ci. goo-17) to prevent an arc being drawn which would be of such a length as to damage adjacent parts of the switch or which would absorb suiiicient energy to prolong the arc and thereby increase the rate of deterioration of the contacts, a stop plate 5 I8 of insulating material is provided. For moving the cam I1 from one position to another, an operating mechanism I9 is provided of the tumbler type, as best indicated in Fig. 3. A rocker 20 is connected to cam I'I by means of a shaft 2|. Rocker 20 is pivoted on shaft 2| which is journalled in bearings provided in a U-shaped supporting structure 22. For opposing the movement of rocker 20 from the vertical position and also for returning the rocker to the vertical position, a spiral spring 23 is provided surrounding shaft 2|, located between the two arms of rocker 20 with its ends 24 and 25 engaging lugs 26 and 21 respectively struck out from the supporting structure 22. An operating handle or lever 28 is provided and pivoted on a pin 29 journalled in bearings in supporting structure 22. Connected to the end of operating handle 28 is a roller 30. Rocker 20 is formed of U-shape with each of the ends of the two arms cut away to form a track 3| having a bottom notch 32 and two side notches 33 and 34. When the switch is in the position indicated in Fig. 1 the roller 30 is located in the notch 32. To rotate `the cam I1 in a clockwise direction, lever 28 is moved to the left and the .o roller rides over track 3| to notch 33 where the switch is locked in position, as indicated in Fig. 2. As rocker 20 rotates about the shaft 2| the bottom of the rocker engages end 24 of spring 23 winding up the spring and producing a spring tension tending to return rocker 20 to the vertical position. To return cam I1 to the position of Fig. l from the position of Fig. 2, lever 2 8 is moved to the vertical position. As lever 28 is moved to this position, roller 30 is moved out of notch 33 and the spring 23 returns the rocker 20 to the vertical position. Thus, it may 'be seen that while the cam I I is moved in a clockwise direction to one operative position under the 1 guidance of the operating handle 28 it is returned to the inoperative position under the action of spring 23. This produces a slow make and quick break contact action. In a like manner the cam I'I is rotated in a counter-clockwise direction by movement of the operating handle 28 to the right so that the roller 30 rides over track 3| and becomes seated in notch 34, as indicated in Fig. 3. When the cam is rotated in a counter-clockwise engages arm 23 moving it from engagement with direction the bottom of rocker 20 25 of spring the switch operating lug 21 thus winding up the spring in vsuch a direction that when the operating lever 28 is again returned to the vertical position the spring 23 returns the rocker to the vertical position. To separate the operating mechanism from the stationary and movable contacts and to protect the operating mechanism from the arcs drawn upon the separation of the cooperating contacts, barrier plates 35 and 36 of insulating material are provided on each side of the operating mechanism as best indicated in Fig. l.

In the above description reference has only been made to the stationary contacts Il and I2 and the action produced by the movement of mechanism on movable contacts I3 and I4. Additional Stationary and movable contacts are provided on the other side of the switch and their operation is similar to the action of the contacts provided on the right of the switch. Any number of stationary and movable cooperating contacts may be provided and different shaped cams secured to shaft 2l for obtaining any desired circuit connections.

If it is desired to provide a switch with a greater number of positions than three it is only necessary to provide in the track 3| the number and location of notches desired similar to notches 32, 33, and 34.

From the foregoing it may be seen that an improved switch of the tumbler type is provided which may be used to control any desired number of circuits with any number of operative positions. Also, a minimum number of parts of rugged construction are used which may be readily assembled together thereby producing a switch having a long life which may be economically manufactured.

/ What I claim as new and desire to secure by Letters Patent of the United States, is:

1. An operating mechanism for an electric switch comprising a supporting structure, a shaft journaled in said supporting structure, a U- shaped rocker carried by said shaft with said shaft secured to the arms of the U, a track on said rocker having a plurality of notches, a spring mounted on said shaft between the arms of the rocker and having ends engaging said supporting structure and the rocker for opposing movement of said rocker from the vertical position, a lever pivoted in said supporting structure and a roller carried by said lever and adapted to engage the notches in said track whereby movement of said rocker is produced by movement of said lever and the positioning of the rocker is accomplished by the location of the roller in one of said notches.

2. An electric switch comprising stationary contacts, movable contacts, a supporting structure, a shaft journaled in said supporting structure, means mounted on said shaft for operating said movable contacts, a U-shaped rocker member mounted on said shaft with said shaft secured to the arms of the. U, tracks in the arms of said rocker having a plurality of notches therein, a spring surrounding said shaft between the arms of the rocker and having ends engaging the supporting structure and rocker for biasing said rocker to vertical position, a lever pivoted on said supporting structure and a roller carried by said lever and adapted to engage the notches of said tracks whereby the switch is operated by movement of the lever and held in position by interengagement between the roller and notches on the track.

3. An electric switch comprising a stationary contact, movable contacts, a supporting structure, a shaft rotatably mounted in said supporting structure, means mounted on said shaft for operating said movable contacts, a ,U-shaped rocker member mounted on said shaft with said shaft secured to the arms of the U, tracks in thearms of said rocker having central notches and notches on opposite sides thereof, a spring surrounding said shaft between the arms of the rocker and having ends engaging the supporting structure and rocker for biasing said rocker to a vertical position, a lever pivoted on said supporting structure and a roller carried by said lever cooperating with the central notches when the rocker is in vertical position and likewise cooperating with the side notches upon movement of said lever to hold said rocker in position against the biasing action of said spring to main- ,4

tain said switch contacts in operative position.

FRED H. TRAVERS.

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