US1590405A - Switching device - Google Patents

Description

June 29 1926.

B. O. AUSTIN SWITCHING DEVICE Original Filed y 12, 1919 WITNESS-ES: /6 M INVENTOR fiddCU/f) O/Iuofln AT.TORNEY Patented June 29, 1926.

UNITED STATES PATENT OFFICE.

' BASCUM O. AUSTIN, OF EAST PITTSBURGH, PENNSYLVANIA ASSIGNOR'TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

SWITCHING DEVICE.

Application filed May 12, 1919, Serial No. 296,616. Renewed January 14, 1926.

My invention relates to control apparatus of the Well-known unit-switch type and it has for its object to provide an improved actuating mechanism whereby a smooth, rolling action may be effected during the closure and opening of the switch contact members.

More specifically stated, it is the ob ect of my invention to provide a switch of the above-indicated character wherein power means and a spring bear upon different parts of the movable contact member, and a lostmotion connection between the movable member and its support is arranged to effect opposing action of the power means and the spring. .o.nly during a predetermined portion of the switchim'ovement.

. My invention may best be understood by reference to the accompanying drawing, wherein the single figure is a view, in side elevation, of the essential parts of a switching device constructed in accordance with the invention.

Referring to thedrawing, the unit-switch structure here shown comprises, in general, a stationary contact member 1; a co-opcrating movable contact member 2; and an actuating mechanism 3 and power-operated means 4 therefor.

The stationary contact member 1 is of a familiar type comprising a bent contact tip 5 which is secured to a bracket or standard 6 that is suitably attached to the top frame member or cover 7 for the entire switch roup.

The movable contact member 2 comprises a similar contact tip 8 that is mounted upon one end of a'switch arm 9, the other end of which is provided with a pin-and-slot or.

other lost-motion connection 10 with a stationary support or bracket 11, which is also secured to the top frame member 7. A coil sprin 12 is secured between the switch arm 9 an the frame 7 bearing upon the switch arm near the lost-motion connection 10. The power means 4 for closing the switch is pivotally secured to the switch arm 9 near the contact tip 8, whereby the switch arm is provided with two pivotal connections-.13, just mentioned, and 14, forming an element of the lost-motion connection 10. A braided shunt or conductor 15 serves to divert current from the spring 12 and the lost-motion a familiar electrically-controlled, fluid-actuated device. The usual insulator 20 is interposed between the pivotal point 13 and the air-cylinder 21, within which a movable piston (not shown) is adapted to travel, as will be understood by those skilled in the art. A magnet valve 22 of well-known construction is employed for the purpose of controlling the supply of fluid pressure to the cylinder 21 and, if desired, an electrical interlock 23, of the familiar type that is employed for auxiliary control circuits, may be attached to the movable piston rod in the usual manner. Since, as stated above, the particular type of power mechanism that is employed is immaterial to my present invention, I do not deem it necessary to further describethe illustrated mechanism.

Assuming the parts of the switching device to occupy the illustrated normal positions, the closing operation thereof may be set forth as follows: Upon the initial upward application of force to the pivotal point 13, the switch arm 9 rotates around the pivotal point 14 until an initial contact of relatively small area is made between the contact tips 5 and 8. Up to this point, the

top portion of the slot in the lost-motion connection 10 is held in engagement and bears upon the pivot member 14 by reason of the biasing effect of the spring member 12 upon the switch arm 9. 'l/Vhen the initial contact has been made between contact tips 5 and 8, the contact tip 8 acts as a temporary fulcrum, upon continued a plication of force to the pivotal point 13, an the right hand end of the switch arm 9 is actuated upwardly until the bottom portion of the lostmotion connection 10 engages the pivot member 14. In this way. a gradual rolling action of the contact tip 8 over the surface of the stationary contact tip 5 occurs until complete electrical contact has been estab lished between the two contact tips.

It will be understood that the opening movements of the switch are the exact reverse of those described, the initial propelling force being supplied by the customary coil spring (not shown) that is located within the air cylinder 21.

Although I have described the operation of the switch as providing a smooth, rolling contact of the tips into the desired'final position, ll desire it to be understood that, by slightly modifying the proportion of parts, any desired degree of sliding or Wiping action may be substituted for the complete rolling action that l have set forth. Consequently, I do not wish to be restricted to the specific structural details or arrangement of parts herein set forth, as various modifications thereof may be made without departing from the spirit and scope of my invention I desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. A switching device comprising co-operating stationary and movable contact members, power means attached to said movable member at a certain point, a spring acting at another point in opposition to said power means, and a lost-motion connection for said movable member including a stationary member located to one side of both the power means and the spring, said power means and said spring acting along substantially parallel paths.

2. A. sw tching device comprising co-opcrating stationary and movable contact members, a support for the movable memacting upon the movable member near said eena-ca tionary and movable contact members, a

support, a lost-motion connection, comprising a pin and slot between said movable contact member and said support, energystoring means acting on said movable member near one end thereof and power means acting at another point on said movable member in opposition to said energy-storing means, said power means and said energy-storing means acting along substantially parallel paths.

5. A switching-device comprising stationary and movable contact members, .a support, a lost-motion connection, comprising a pin and slot between said movable contact member and said support, energy-storing means acting on said movable member near one end thereof and power means acting atanother point on said movable member in opposition to said energy-storing means, said power means and said energy-storing means acting along substantially parallel paths, and said slot extending in a parallel direction to said paths;

In testimony whereof, I have hereunto subscribed my name this 30th vday of April 1919.

BASCUM o. AUSTIN.

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