US2303425A - Disconnecting contact - Google Patents

Description

Filed Feb. 27, 1941 Figi WO RM a o. mw ,R E M5 m lm B Patented Dec'. l, 1942 DISCONNECTING CONTACT Charles E. Bckham, Pittsburgh, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a. corporation of Pennsylvania Application February 27, 1941, Serial No. 380,827

Claims.

My invention relates, generally, to electric switches and, more particularly, to the contact members of electric switches suitable for separating or disconnecting current carrying members, as, for example, on circuit breakers utilized in metal-clad switchgear.

In metal-clad switchgear of either the vertical lift or the horizontal drawout type for circuits of high ampere capacity, it is desirable that the primary disconnecting contacts be arranged for flat bar mounting in order to make the most eflicient use of the limited available space.

An object of my invention, generally stated, is to provide a disconnecting contact which shall be simple and eilicient 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 use with iiat bar conductors.

Another object of my invention is to provide for maintaining uniform contact pressure between the contact members of a disconnecting switch.

A further object of my invention is to avoid the use of exible shunts in a disconnecting switch having a plurality ol movable contact lingers.

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

In accordance with my invention, current is conducted between a movable contact and a stationary contact by means of a plurality of bridging members which are movably mounted on the movable contact by means of a mounting plate that has grooves for maintaining the desired spacing between the bridging members. The bridging members are oppositely disposed in pairs, each pair being held in place by a retainer with a flat spring so disposed between each bridging member and its retainer that pressure is applied on the contact surfaces.

For a fuller understanding of the nature and objects of my invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which:

Figure `1 is a view, in elevation. oi a disconnecting contact constructed accordingto my invention,

Fig. 2 is a view, in section, taken along the line II-lI oi' Fig. 1, and

Fig. 3 is another view, in section, taken along the line III-III oi' Fig. 2.

contact shown therein comprises two parts, a movable contact I0 and a stationary contact II. As shown, the stationary contact is a rectangular conductor suitable for connecting to the bus bars of a switchgear structure (not shown).

The movable contact I0 comprises a plurality of bridging contact fingers I2 for conducting current between a rectangular member I3 and the rectangular member II. The member I 3 may be mounted on a circuit breaker or other electrical apparatus (not shown) which is to be disconnected from the conducting member II. The bridging contact ngers I2 are movably mounted on the conducting member I3 by means of a mounting plate I4 which is secured to the end of the conducting member I3 by screws I5. The mounting plate I4 is provided with grooves or notches I6 for retaining the contact fingers I2 in spaced relation across the conducting member I3. 'I'he contact fingers I2 are provided with notches I 'I which cooperate with the mounting plate I 4 to limit the longitudinal movement of the contact fingers on the conductor I3.

As shown, the contact fingers I2 are disposed on the conductor I3 in pairs, the members of each pair being on opposite sides of the rectangular conductor I3. 'I'he two members of each pair are retained in place by means of a common retainer I8 which is disposed substantially midway between the ends of the fingers. The retainers I8 are provided at each end with a channel I9 for guiding a contact finger I2 and for retaining a flat spring 2| which is disposed be- IReferring to the drawing, the disconnecting tween the retainer I8 and the contact finger I2. As shown in Fig. 2, thel iiat springs 2| are curved and the ends of each spring engage one of the contact fingers I2 to maintain contact pressure between the finger I2 and the conducting members I I and I3. In this manner, the fingers of each pair are biased toward each other by the action of the springs 2I and the retainer I3.

In order to prevent collapsing of the contact fingers when they are withdrawn from the conductor II, a oating bar 22 is disposed between the contact ngers. The bar 22 is provided with notches 23 for assisting in maintaining the desired spaced relation between the contact fingers. The ngers I2 are provided with notches 24 for retaining the floating bar 22 in position between the contact fingers.

Ii it is desired to limit the sidewise movement of the contact fingers, pins 25 may be inserted through elongated openings 26 provided in the retainers I8; in this manner a predetermined amount of misalignment between the conducting members Il and I3 may be permitted. However, the permissible amount of misalignment may be governed by the size of the elongated openings 26.

Vertical alignment of the contact iingers I2 is maintained by a pair of plates 21, one of which is secured on top of the conductor I3 by screws 28 and the other of which is secured to the bottom of the conductor I3 by similar screws 28. The pins 25 extending through the plates 21 may be retained in position by cotter keys 29.

From the foregoing description, it is apparent that I have provided a contact assembly having a relatively high ampere capacity, since the use of exible shunts for conducting the current is entirely avoided and the current is conducted through rigid members, Furthermore, a uniform contact pressure between each of the bridging fingers and the rectangular conductors is maintained, since the iingers of each oppositely disposed pair are provided with individual springs for maintaining the contact pressure. Thus, the use of equalizing members for distributing the contact pressure between the contact lingers is avoided. Also. the use of helical springs, which require more space than flat springs of the type herein disclosed, is avoided.

I do not desire to be restricted to the particular form or arrangement of parts herein shown and described, since it is evident that they may be changed and modied without departing from the spirit and scope of my invention as dened in the appended claims.

I claim as my invention:

l. A disconnecting contact comprising, a conductor, a plurality of pairs of contact ngers disposed on opposite sides of said conductor, a retainer for each pair of oppositely disposed contact fingers, said retainer having channel-shaped ends for receiving the fingers, and resilient means disposed between the ngers and the retainers for biasing the fingers of each pair toward each other.

2. A disconnecting contact comprising, a conductor, a plurality of pairs of contact fingers disposed on opposite sides of said conductor, a retainer for each pair of oppositely disposed contact ngers, and a curved at spring member disposed between each linger and its retainer in alignment with the iinger for biasing the fingers of each pair toward each other, said retainer engaging said spring substantially midway between its ends which engage the nger.

3. A disconnecting contact comprising, a conductor, a plurality of pairs of contact iingers. movably mounted on opposite sides of said conductor, means on said conductor for limiting longitudinal movement of said fingers, said means having recesses therein for maintaining the flngers in spaced relation, a retainer for each pair of oppositely disposed contact lingers, said retainer having channel-shaped ends for receiving the iingers, and resilient means disposed in said channels between each nger and its retainer to engage the nger on opposite sides of the retainer for biasing the ngers of each pair toward each other.

4. A disconnecting contact comprising, a conductor, a plurality of pairs of contact fingers movably mounted on opposite sides oi said conductor, means on said conductor for limiting longitudinal movement of said fingers, a movable retainer for each pair of oppositely disposed contact ngers, said retainer having channel-shaped ends for receiving the lingers, means for limiting the movement of said retainers, and resilient means disposed in said channels between each nger and its retainer for biasing the lingers oi.' each pair toward each otner. 5. A disconnecting contact comprising, a con' ductor, a plurality of pairs oi' contact fingers movably mounted on opposite sides of said conductor, means on said conductor for limiting longitudinal movement of said iingers, a movable retainer for each pair of oppositely disposed contact fingers, means for limiting the transverse and the longitudinal movement of said retainers.

y and a iiat spring member disposed between a tinger and its retainer in alignment with the ringer for biasing the fingers of each pair toward each

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