US2443047A - Electric switch contact - Google Patents

Description

June 8,1948 J,w,McLA.N 2,443,047

ELECTRIC SWITCH CONTACT Filed May 51, 1946 Inventor-r Joseph W. McClain,

b win 77w.

His Attorne g.

Patented June 8, 1948 ELECTRIC SWITCH CONTACT .Joseph W. McClain, Logansport, Ind., assignor to General Electric Company, a corporation of New York Application May 31, 1946, Serial No. 673,277

My invention relates to electric switch contacts,

and has for its object the provision of means for rendering substantially shock-proof the heavy contacts of large electromagnetic contactors.

The invention will be more fully understood and its objects and advantages further appreciated by referring to the following detailed specification taken in conjunction with the accompanying drawing, in which Fig. 1 is a side elevation of an electromagnetic contactor embodying my invention, Fig. 2 is an end view of the contactor shown in Fig. 1, and Fig. 3 is an exploded perspective view showing in detail the mounting of the movable contacts shown in Figs. 1 and 3.

Referring now .to the drawings, and particularly to Figs. 1 and 2, I have shown an electromagnetic contactor mounted upon a base I and comprising a rectangular shaft 2 rotatably mounted at its ends in bearings 3. The shaft 2 carries a plurality of movable contacts 4 and a magnetizable armature 5. The contacts 5 are arranged to engage and disengage cooperating fixed contacts 6 mounted upon the base I. The shaft 2 also-carries a weight 1 arranged to bias the shaft 2 to a normal position of contact disengagement. A pair of electromagnets 8 are mounted upon the base I for cooperation with the armature 5. When the electromagnets are energized they attract the armature 5, thereby to move the shaft 2 and to contact engaging position.

At Fig. 3, I have shown in detail the mounting of the movable contact blocks 4. Each contact block is loosely mounted for pivotal movement in a generally V-shaped supporting saddle 9 fixed to the rotatable shaft-2. The contact block 4 is biased against the front side of the saddle 9 by a wipe spring I0. The wipe spring I is a helical compression spring positioned between the back of the contact block 4 and a spring seat formed-by an up-turned ear II on the rear side of the supporting saddle 9.

The contact block 4 is provided at its lower end with a V-shaped transverse notch l2, and is pivotally mounted upon a knife-edge bearing l3 protruding from the front side of the saddle 9 and cooperating with the V-shaped notch l2. The block 4 is held on its knife-edge support by the wipe spring In.

In order to prevent lateral displacement of the contact block 6 within the saddle 9, I provide a r pair of guide plates I 4, 15 attached to the front side of the supporting saddle! and embracing the sides of the contact block I. In the embodiment of the invention shown in the drawing, the guide plates ll, I are formed by the sides of a U-shaped 2 Claims. (Cl. 200166) 2 member IS, the lower end of which is turned up to form the knife-edge bearing l3. The U-shaped member is welded or otherwise fixedly attached to the front side of the supporting saddle 9.

I have found that with the construction hereinbefore described, the contact blocks 4 are subject to longitudinal displacement within the guide plates l4 and IS in the event of severe impact applied to the contactor. In order to prevent such longitudinal displacement while permitting the slight pivotal movement of the contact blocks necessary for proper wiping action, I provide between each contact block and at least one of the guide plates I, I5 a lost motion interlocking connection. Such a connection may be formed by providing at one'sideof each contact block 4 a pin arranged in interfltting relation with a slot in one of the guide plates l4, l5. Specifically in the illustrated form of the invention, I have shown a pin formed upon the side of each contact block 4 by threading into the contact block a fillister head bolt ll. protrudes into an elongated slot iii in the guide plate l5. It will be evident that the pin and slot connection l1, l8 between the contact block 4 and the guide plate l5 prevents longitudinal displacement of the contact block while permitting a limited pivotal movement of the block on its knife-edge support l3.

While I have described only a preferred embodiment of my invention by way of illustration, many modifications will occur to those skilled in the art and I therefore wish to have it understood that I intend in the appended claims to cover all such modifications which fall within'the true spirit and scope of my invention.

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

1. An electric contactor comprising a movable contact support providing a knife-edge bearing, a contact block pivotally mounted on said knifeedge bearing for movement relative to said support, a pair of guide plates embracing the sides of said contact block to prevent lateral displacement of said block in said support, and a lost motion pin and slot connection between said contact block and at least one of said guide plates, thereby to prevent longitudinal displacement of said block while permitting limited pivotal movement thereof. v

2. An electric contactor comprising a rotatable contact support providing a knife-edge bearing, a movable contact block loosely mounted upon said knife-edge bearing for pivotal movement relative to said support, spring means retaining The head of the bolt l'l 3 said contact block in position upon said knife-- edge bearing while permitting limited pivotal movement 01 said block, a pair of guide plates embracing the sides 01 said contact block to prevent lateral displacement of said block in said support, and a lost motion pin and slot connection between said contact block and at least one of said guide plates for preventing longitudinal displacement of said block while permitting limited pivotal'movement thereof in said support.

JOSEPH W. McCLAIN.

'4 REFERENCES CITED The following references are 01 record in the file or this patent:

v UNITED sums PATENTS Number Name Date 706,527 Carichoi! Aug. 12, 1902 2.1mm schaelchlin Dec. 26, 1939 2,397,113 Igiehart Mar. 26, 1946

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