US2584707A - Self-aligning armature - Google Patents

Description

Feb. 5, 1952 s. F. JARVIS ETAL SELF-ALIGNING ARMATI'RE Filed July 14, 1950 Inventors:

Samuel F Jarvis,

James R. Burch,

bg Their Attovheg.

Patented Feb. 5, 1952 SELF-ALIGNING ARMATURE Samuel F. Jarvis and James R. Burch, Schenec tady, N. Y., assignors to General Electric Company, a corporation of New York Application July 14, 1950, Serial No. 173,818

3 Claims. 175-336) Our invention relates to alternating current contactors and more particularly to the means for connecting the operating arm upon which the contacts are mounted to the armature of the contactor. More specifically the invention relates to a frictional self-aligning mounting between an operating member and an armature in the form of a transverse bridging member.

An object of our invention is to connect the operating arm securely to the armature of a contactor with a light weight friction joint mechanism therebetween flexible enough to allow the armature to seat itself evenly against the pole pieces of the electromagnet when the armature is picked up.

To reduce to a minimum the amount, of power required from the electromagnet to operate an operating arm supporting multiple contacts, the operating arm must be of light, construction. When a bridging armature member is rigidly attached to an operating arm of such light construction, normal factory tolerances for grinding and squareness of parts mak it diiiicult to guide the arm accurately so that the armature seats itself squarely against the poles of the electromagnet. If the armature member is skewed with respect to the poles when it is picked up, an edge of one of the engaging surfaces of the armature strikes a pole face of the electromagnet first, setting up a vibration of the entire movable structure about the pole faces. This vibration is sustained by the inertia of the structure and the pulsating forces between the poles and the armature causin a chattering of th contacts.

According to our invention a contactor provided with an electromagnet having a hollow coil and pole pieces is provided with an operating arm of the impression to constrain the boss against the closed end of the strap.

For a better understanding of our invention reference is made to one embodiment thereof in which Fig. 1 is a partly sectional view of the apparatus and Fig. 2 is a view along 22 of Fig. 1 looking in the direction of the arrows.

According to the drawing a bridging armature member I seats against an electromagnet 2 of a contactor at points 3, 4 and 5. Clearance is Drovided between the surfaces at 4. Member I is secured to an operating arm 6 of the contactor for supporting multiple contacts (not shown) which is slidable in the hollow center of th coil 1 of electromagnet 2. A tack having a spherical surface is secured to a surface 9 of member I by a stem I0 projecting into member I to provide a boss 8 on surface 9.

U-strap H secured to the end of operating arm 6 is provided with an outward projecting spherical impression I2 in its closed end. A spring I3 contacting the outside surface of impression I! is secured at both ends in a pair of dogs I on member I flanking boss 8 to secure together bridging member I and operating arm 8. Spring I3 is provided with a spherical impression I5 contacting the outer surface of strap I I.

The tension of spring I3 is merely enough to provide a frictional joint between bridging armature member I and operating arm 8 so that if armature I is tilted with respect to poles 3 and 5, when it is picked up by. electromagnet 2, the-contact surfaces of armature I can seat flatly upon the faces of poles 3 and 5 with no further movement of arm 6.

While certain specific embodiment hav been shown and described. it will, of course, be understood that various modifications may b made without departing from the invention. The appended ciaims are, therefore, intended to cover any such modifications within the true spirit and scope of the invention.

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

1. An adjustable friction mounting between a transverse bridging member and an arm provided with a strap member and having a spherical impression therein, said bridging member having a spherical boss and flanking pairs of dogs provided thereon, and a flat spring secured by said dogs and contacting the raised surface of said impression to force said boss into contact with the recessed surface of said impression whereby said bridging member can tilt with respect to said arm.

2. In an electrical contactor including an electromagnet having a coil and pole pieces, an operating arm slidably mounted in the center of said coil and an armature for bridgin said pole pieces, means for pivotally mounting said armature upon said operating arm including a U-shaped strap member having an outward projecting spherical impression in the closed end thereof and mounted upon the end of said operating arm, said armature being provided with a spherical boss for projecting into the inside surface of said impression and a pair of dogs formed thereon flanking said boss and a flat spring secured at the ends thereof by said dogs and engaging the outside surface of said impression to restrain said armature against said strap, whereby said armature can tilt with respect to said operating arm to seat flatly against said pole pieces in the picked up position of said armature.

3. In an electrical contactor including an electromagnet having a coil and pole pieces, an operating arm slidably mounted in the hollow center of said coil and an armature member for bridging said pole pieces, means for pivotally mounting said armature on said arm including a U-shaped strap member mounted upon an end thereof and provided with a first spherical impression in the closed portion thereof, said armature member being provided with a spherical boss engaging the inside surface of said first impression and a pair of dogs flanking said boss, a

REFERENCES CITED The following references are of record in the.

file of this patent:

UNITED STATES PATENTS Number Name Date 1,182,329 Stratton et al May 9. 1918 1,392,561 Duffy Oct. 4, 1921 1,491,965 Nelson Apr. 29, 1924 1,830,355 Farr Nov. 3, 1931 1,883,437 Adams Oct. 18, 1932 1,936,098 Pengilly et a1. Nov. 21, 1933 1,948,374 Frese Feb, 20, 1934 2,172,460 warms Sept, 12, 1939

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