US2300893A

US2300893A - Disconnecting contact

Info

Publication number: US2300893A
Application number: US393342A
Authority: US
Inventors: Benjamin I Hayford
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1941-05-14
Filing date: 1941-05-14
Publication date: 1942-11-03
Anticipated expiration: 1959-11-03

Description

wlTNEssEs:

Nov. 3, 1942.' a. l. HAYFoRD 2,300,393

' DIscoNNEcTING CONTACT 'Filed may 14, 1941 fQ-f l 14 Patented Nov. 3, 1942 to Westinghouse Electric la Manufacturing Company, Ea'st` Pittsburgh, Pa., a corporation of Pennsylvania` `appagante May 14, 1941, serial 110.3935112 -5 claims. (ci. 173-363) r My invention relates, generally, to electric switches and, more particularly, to the disconnecting contact members of electric switches suitable for disconnecting removable circuit breakers from the current conductors of a power` system.

The conventional disconnecting contact assembly for metal clad switchgear, as manufactured at the present time by the manufacturers of rswitchgear apparatus, utilizes circular or garter springs wrapped around the contact segments or fingers to exert radial contact pressure. .With springs of this type there is a possibility of one of them breaking and, wheny straightened out, being of sufficient length to ground the circuit breaker or the bus.

An` object of my invention, generally stated, is to provide a disconnecting contact which shall be simple and eflicient in operation and which may be economically manufactured and installed.

A more specific object of my invention is to provide a disconnecting contact suitable for connecting round current conducting members.`

Another object of my inventionis to provide for utilizing fiat springs to apply radial pressure to the contact lingers of a disconnecting contact of the circular type.

A further object of my invention is to enclose the contact members of a circular disconnecting contact.

Other objects of my invention will be explained hereinafter or will be apparent to those skilled in the art.

According to my invention, the contact members of a disconnecting contact of the circular type are enclosed by a cylindrical sleeve which also functions to maintain the contact fingers in spaced relation. A fiat spring is disposed between 'each of the contact fingers and the sleeve i tially in elevation, of a disconnecting contact embodying my invention;

Fig. 2 is a sectional view, taken along the line II-II of Fig. l; and

Fig. 3 is a view, in perspective, of one of the contact fingers and its cooperating spring member.

Referring to the'drawing, and particularly to Fig. l, the disconnecting contact shown therein is comprised of two parts, a moving contact IG and a stationary contact I I. The stationary contact II'may comprise a round stud I2 which is'.

mounted in a parcelain bushing I3. The stud I2 is provided with a shoulder IrlV which is disposed on one side of a partition i5 in the bushing I3 and a nut I6 which may be screwed up against the other side of the partition I5, thereby securely fastening the stud I2 in the bushing I3.

The movingcontact Iii may comprise a stud Il which may be part of a circuit breaker structure (not shown) anda plurality of contact ngers I8 disposed around the periphery of the stud I'l, The contact fingers it are enclosedv by a sleeve I9, which is preferably composed of steel or other suitable material.

As shown in Fig. 3, an individual spring 28 is provided for each onel of thecontact iin-gers I8. Each end of the spring 20 is slotted and portions 2l of the spring are bent over to engage the sides of the contact finger, thereby retaining the 1inger and the spring in assembled relation. As shown in, Fig. l, the metal sleeve I9 is provided with an inwardly extending projection 22 which has notches 23 for receiving the springs 20, thereby maintaining the Contact lingers I8 in spaced relation around the periphery of the stud Il. In this manner the springs 20 function to maintain contact pressure between the fingers I8 and the studs I2 and il, as well as to retain the contact ngers in spaced relation.

A groove 24 is provided in the stud I'I for receiving an inwardly extending projection 25 on each of the contact fingers I8, thereby retaining the lingers on the stud I1 when the moving Contact I8 is disengaged from the stationary contact I I. It will be noted that the groove 24 is slightly wider than the projection 25 on the contact ngers I3. In this manner a predetermined amount of longitudinal movement of the contact fingers I8 with respect to the stud I1 is permitted, thereby providing a wiping action between the contact fingers I8 and the stud I1. However, the longitudinal movement is limited by the groove 24 and the projection 25.

In order to prevent collapsing of the contact lingers I8 when they are disengaged from the stud I2, the sleeve I9 is provided with an inwardly extending flange 26 which is disposed to engage an extension 2'I on each of the springs 20. As explained hereinbefore, the portions 2| of the springs 20 rmly grip the contact fingers I8. In

this manner the radial movement of the contact ingers is limited by the flange 25 on the sleeve I9 and the extension 21 on the spring 20, and collapsing of the Contact ngers is prevented.

From the foregoing description it is apparent that I have provided a disconnecting contact assembly which is full floating and permits relative niisalignment between the moving contact Hl and the stationary contact H. Furthermore, the use of flexible shunts in the contact structure is entirely avoided since the current is conducted between the studs l2 and I1 by the bridging contact members I8 which are of a rigid construction. I have also eliminated the use of circular or garter springs which, as explained hereinbefore, may cause serious trouble in the event of breakage of one of the springs. The enclosing sleeve herein described not only cooperates with the at springs to maintain the desired contact pressure, but also aiords protection for the current conducting parts of the contact assembly.

Since numerous changes may be made in the above described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. A disconnecting contact comprising, a round stud, a plurality of contact fingers disposed around the periphery of and supported by said stud, means on the stud cooperating with means on the ngers for limiting longitudinal movement of the fingers, a tubular sleeve surrounding the iingers. means on said sleeve for retaining the ngers in spaced relation. resilient means disposed between said sleeve and said iingers for maintaining contact pressure between the stud and the fingers. and extensions on said resilient means for engaging opposite sides of said fingers to retain them in the sleeve.

2. A disconnecting contact comprising, a round stud, a plurality of contact ngers disposed around the periphery of said stud, means on the stud cooperating with means on the fingers for limiting longitudinal movement of the iingers, a cylindrical sleeve surrounding the fingers, internally projecting means on said sleeve for retaining the iingers in spaced relation, and a spring disposed between each of said fingers and the internally projecting means on said sleeve for maintaining contact pressure between the stud and the fingers.

3. A disconnecting contact comprising, a round stud, a plurality of rigid contact fingers disposed around the periphery of and supported by said stud, a tubular sleeve surrounding the fingers, an individual spring for each contact nger disposed between the finger and the sleeve for maintaining contact pressure between the stud and thefinger, means on said springs for engaging said fingers, and means on said sleeve engaging said springs to retain the fingers in spaced relation.

4. A disconnecting contact comprising, a round stud, a plurality of rigid contact ngers disposed around the periphery of said stud, a cylindrical sleeve surrounding the ngers, an individual spring for each contact finger disposed between the finger and the sleeve for maintaining contact pressure between the stud and the finger, and means on said springs for engaging said lingers to retain them in spaced relation, said springs being disposed in notches provided on the inner surface of said sleeve.

5. A disconnecting contact comprising, a round stud, a plurality of rigid contact iingers disposed around the periphery of and supported by said stud, a cylindrical sleeve surrounding the fingers, an individual spring for each contact linger disposed between the iinger and the sleeve for maintaining contact pressure between the stud and the finger, means on said springs for engaging said fingers, and means on said sleeve engaging said springs to retain the iingers in spaced relation, said sleeve having an internal fiange disposed to engage one end of said springs to limit the radial movement of said iingers.

BENJAMIN I. HAYFORD.