US1705692A - Switch mechanism - Google Patents

Description

March '19, 1929. v VOGEL 1,705,692

SWITCH MECHANI SM Filed March 51, 1925 WITNESSES: INVENTOR W Carl Voye/ ATTORNEY Patented Mar. 19, 1929.

UNITED STATES PATENT-OFFICE.

CARL VOGEL, OF EERLIN-SCHONEBERG, GERMAN Y, ASSIGNOR T WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

swr'ron: MECHANISM.

Application filed March 31, 1925, Serial No. 19,627, and in Germany April 1, 1924.

My invention relates to actuatingmechanism and particularly to mechanism for imparting a quick or snap action to an electrical switch.

One object of my invention is to provide an actuating mechanism for switches and apparatus requiring quick-movements in opposite directions, that is simple in construction and which is adaptable particularly to snap switches of the tumbler type.

Another object of my invention is to provide an actuating mechanism of the overcenter type in which the pressure of the switch member in engagement with a contact member is maintained or actually increased until the instant the switch member is separated from the contact member with a snap action and during the time that the actuating mechanism is approaching the central position of its movement.

Another object of my invention is to provide an over-center actuatin mechanism for an electric switch that is adaptable for use as a double-throw switch wherein there is no central or neutral position, but wherein the switch member is yieldingly maintained in either of two operative positions. I

These and other objects that will be made apparent throughout the further description of my invention are attained by means of the actuating mechanism hereinafter described and illustrated in the accompanying drawin wherein'the figure is an elevational View 0 actuating mechanism embodying features of my invention and shown applied to a double throw switch.

Referring to the drawing, the actuating mechanism includes a supporting base 1 made preferably of insulating material and upon which a switch actuating earn 2 is pivotally mounted by means of a shaft 3. The cam comprises a disk having two arcuate surfaces 4 and 5 that are oppositely disposed and c onverge to points'6 and 7 at opposite ends of the cam. A switch member 8, preferably consisting of a flat bronze strip which may be flexed when pressed into engagement with contact members 9 and 10, is rigidly secured to the cam 2 and'is so positioned that it alternately engagesthe contact members 9 and 10 when the cam niember 2 is moved from the position shown to its other operative position indicated by the dot-and-dash center line A. The cam 2 is actuated by means of a pair of operating arms 11 and 12 that are pivotpoints 19 and 20 and the shaft 16. The pur- I pose of the adjustment will hereinafter be made apparent.

The free ends of the operating arms 11 and 12 are provided with rollers 21 and 22 respectively, that as indicated in the drawing normally engage opposite surfaces 4 and 5 of the cam member 2. The arms 11 and 12 are normally biased in engagement with the cam surfaces by means of a helical spring 23 that is pivotally connected between them. The bar 15 is provided with an operating handle 24 by means of which the bar may be moved from the position shown in the drawing to a position indicated by the dot-anddash center line B.

When the parts are in the position shown in the drawing, the switch member 8 is yieldingly biased to engage the contact member 9. When it is desired to move the switch member into engagement with the switch contact 10, the rocking bar 15 is moved to the position B which causes the rollers 21 and 22 to be moved into engagement with the opposite surfaces 5 and 4 respectively, of the cam member 2. As the rollers 21 and 22 are moved toward the pointed ends of the cam, the pressure of contact between the switch member 8'and the contact member 9v is increased because of the increase in the lengths of the lever arms of the forces applied to the cam by the rollers asthey approach the pointed ends thereof, and by reason of the increased tension of the spring 23 which is expanded as the operating arms are separated.

Because of the rollers 21 and 22 and the pointed ends of the cam member 2, there can be no stable central or neutral position and consequently increasing pressure is applied between theswitch member and the contact member 9 until the rollers pass over the points of the cam, at which time the spring 23 will contract and cause the rollers 21 and 22 to rotate the cam and thereby bring the switch member 8 into engagement with the contact member 10. By reason of the adjustments of the points of attachment of the operating arms with respect to the shaft 16, the arms may be so adjusted that the rollers simultaneously engage the points on the cam and simultaneously act upon the opposite surface of the cam to cause it to change position with a snap action.

It willsbe seen from the foregoing that the movement of the cam is entirely independent of the position of the operating handle 24 after the rollers have moved past the central position. The hand of the operator therefore cannot interfere with the snap action of the switch.

The movement of the switch is limited by means of stop shoulders 25 and 26 on the base member 1 that are engaged by an extension 27 secured to the cam. Movement of the free ends of the operating arms 11 and 12 is also limited by inclined surfaces 28 and 29 on the base member which are engaged by the rollers 21 and 22 respectively.

The construction is simple and inexpensive and is applicable to a variety of switch devices wherein snap action movement of the switch member is desired.

While I have described and illustrated several embodiments of my invention, it will be apparent to those skilled in the art that various changes, modifications, substitutions, omissions and additions may be made in the apparatus illustrated Without departing from the spirit and scope of my invention, as set forth in the appended claims.

I claim as my invention:

1. An over-center operating mechanism comprising a pivoted cam member having opposite cam surfaces converging toward opposite ends thereof, a rocking member, a pair of operating arms pivotally connected thereto and having their free ends yieldingly engaging opposite surfaces of the cam member for imparting movement thereto when the said operating members are moved into engagement respectively with the opposite cam surfaces and means for relatively adjusting the operating arms.

2. Switch mechanism comprising a pivoted cam member having opposite cam surfaces converging toward opposite ends thereof, a stationary contact member, a movable switch member connected to the cam member and movable thereby into and out of engagement with the contact member, a rocking member pivoted eccentric to the cam member, a pair of operating arms pivotally connected thereto and having their free ends yieldingly engaging opposite surfaces of the cam member for imparting movement thereto when the said operating members are moved into engagement respectively with the opposite cam surfaces.

In testimony whereof, I have hereunto subscribed my name this 12th day of March, 1925.

CARL VOGEL.

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