US2498296A

US2498296A - Hinged-panel switchboard

Info

Publication number: US2498296A
Application number: US758202A
Authority: US
Inventors: Mark A Pringle
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1947-06-30
Filing date: 1947-06-30
Publication date: 1950-02-21
Anticipated expiration: 1967-02-21

Description

Feb. 21, 1950 PRlNGLE 2,498,296

HINGED-PANEL SWITCHBOARD Filed June 30, 1947 Fig.1.

INVENTOR WITNESSES:

'fl/l I Ma/"A APr/hy/6. ATTOREEY Patented Feb. 21, 1950 HINGED-PAN EL SWITCHBOARD Mark A. Pringle, Teaneck, N. J., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 30, 1947, Serial No. 758,202

7 Claims.

My invention relates, generally, to switchboards and, more particularly, to switchboards having hinged panels on which are mounted protective relays of the induction type.

Rotary movement of a panel on its hinges tends to cause rotation of the relay induction element because of its inertia. Accidental closing of the relay contact members frequently occurs when a panel is being opened or closed, thereby causing tripping of the circuit breaker controlled by the relay. Such instances of false tripping have caused interruptions of electrical circuits to important equipment and have shut down continuous processes with wasteful results. 7

An object of my invention, generally stated, is to provide a switchboard of the character described 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 prevent the accidental tripping of a circuit breaker controlled by a relay mounted upon a hinged panel.

Another object of my invention is to prevent closing the contact members of a relay by swinging the panel upon Which the relay is mounted.

A further object of my invention is to restrain the rotary movement of a hinged switchboard panel.

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

In accordance with one embodiment of my invention, the rotary movement of a hinged panel having relays thereon is so restrained by a fluidpressure device that the panel cannot be swung sufiiciently fast to cause the closing of the relay contact members.

For a better 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 front elevation, of a switchboard structure embodying the invention; and

Fig. 2 is an enlarged view, in section, of a fluid-pressure device utilized in practicing my invention.

Referring to the drawing, and particularly to Figure 1, the switchboard structure shown therein is of the metal-enclosed type and comprises a plurality of cells or housings l0, each of which is provided with a hinged panel H. The panels ll perform the dual function of providing access to the interior of the housings and also supporting the various electrical devices, such as meters and relays usually found on a switchbaord. When the panels are closed, they constitute the front of the switchboard structure.

In order to simplify the drawing, the electrical apparatus, such as circuit breakers and switches, usually provided within the housings has been omitted. Also, some of the devices, such as meters and control switches, usually provided on switchboards, have been omitted from the panels H.

As shown, a plurality of relays l2 and their associated test switches [3 are mounted on each panel II. The relays l2 are of the short-time induction-disc type, well-known in the art, in which the contact members of the relay are closed by the rotation of a disc which is mounted on a vertically disposed axis.

It has been found that the induction element of such a relay has sufficient inertia to be caused to rotate about its vertical axis when the panel upon which the relay is mounted is swung too rapidly about the panel hinges. Thus, the contact members of the relay may be unintentionally closed by the rotation of the hinged panel, thereby causing the tripping of th circuit breaker controlled by the relay and interrupting the power circuit controlled by the circuit breaker. Continuous processes have been shut down by such accidental tripping of power circuit breakers, thereby causing the loss of expensive materials.

In order to prevent the unintentional closing of the relay contact members and the accidental tripping of the circuit breakers controlled by the relays, I have devised a pneumatic or fluidpressure device 14 which, when connected to the vertically hinged switchboard panel I l by a suitable linkage mechanism IE, will restrain the acceleration of the panel sufficiently to minimize the transmission of rotary movement to the induction elements of the relays. The device l4 may be mounted upon the switchboard panel and connected to the housing I U by the linkage mechanism l5 in the manner shown in Fig. 1.

As shown in Fig. 2, the device l4 comprises an enclosed cylinder IS in which is disposed a double-acting or double-ended piston assembly H. The piston assembly [1 may be driven by a rack 18 and a pinion H) which is secured to a shaft 2| which, in turn, is rotated by the linkage mechanism l5. The cylinder I6 may be filled with a fluid, such as oil, which is prevented from leaking around the shaft 2| by a packing nut 22 which compresses a packing material 23 against the shaft 2 I. A port 24, which connects the opposite ends of the cylinder I6, is provided in the cylinder wall. A needle valve 25 may be adjusted to regulate the flow of fluid through the port 24.

It will be seen that rotary movement of the panel ll about its hinges will be restrained by the building up of fluid pressure within the cylinder depending upon the direction of panel movement. As the piston assembly is moved in one direction or the other, the fluid must transfer from one end of the cylinder to the other through the port 24-. The rate of flow of fluid through the port may be regulated by adjusting the needle valve 25. In this manner, the panel may be prevented from being accelerated too rapidly, thereby preventing the unintentional closing of the contact members of the relays mounted upon the panel.

As explained hereinbefore, the device I 4 is of the double-acting type which will restrain both the opening and the closing movements of the panel. This is desirable when relays of different types are mounted upon the same panel since some of the relays may be so constructed that their contact members are closed by the opening movement of the panel while other relays may be affected by the closing movement of the panel. In case it is desired to restrain movement of the panel in one direction only, this may be done by providing a single acting piston in the cylinder and a check valve So disposed in the piston that movement of the piston is restrained in only one direction.

From the foregoing description, it is apparent that I have provided a simple and effective means for preventing th unintentional mechanically induced operation of relays mounted upon hinged panels, thereby preventing the accidental tripping of circuit breakers or other devices controlled by the relays. Furthermore, it is not necessary to disconnect the relays from service while the panels are opened, as has been done in the past in order to prevent the accidental tripping of the circuit breakers. It is obvious that when the relaysare disconnected'from service, the protection normally afforded by the relays is lost while they are disconnected.

Since numerous changes may be made in the above described construction and diiferent 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. In a switchboard structure, in combination, a housing, a panel hinged to the housing, a relay mounted on the panel, and restraining means connected to the panel and the housing for controllingthe rotary movement of the panel to prevent closing the contact members of the relay by accelerating the panel too rapidly, said restraining means being constructed to permit the panel to remain in any desired position.

2. In a switchboard structure, in combination, a housing, a panel hinged to the housing, a relay mounted on the panel, and restraining means connected to the panel and the housing for preventing accelerating the panel so rapidly that the contact members of the relay are closed by the acceleration of the panel, said restraining means being constructed to permit the panel to remain in any desired position.

3. In a switchboard structure, in combination, a housing, a panel hinged to the housing, a relay mounted on the panel, and fluid-pressure means connected to the panel and the housing for restraining the acceleration of the panel to prevent closing the contact members of the relay by the rotary movement of the panel, said fluid-pressure means being constructed to permit the panel to remain in any desired position.

l. In a switchboard structure, in combination, a housing, a panel hinged to the housing, a relay mounted on the panel, restraining means connected to the panel and the housing for preventing accelerating the panel so rapidly that the contact members of the relay are closed by the acceleration of the panel, and means for adjusting said restraining means to vary the rate of acceleration of the panel, said restraining means being constructed to permit the panel to remain in any desired position.

5. In a switchboard structure, in combination, a housing, a panel hinged to the housing, a relay mounted on the panel, fluid-pressure means connected to the panel and the housing for restraining the acceleration of the panel to prevent closing the contact members of the relay by the rotary movement of the panel, and valve means for adjusting said fluid-pressure means to vary the rate of acceleration of the panel, said fluidpressure means being constructed to permit the panel to remain in any desired position.

6. In a switchboard structure, in combination,

a housing, a panel hinged to the housing, a relay mounted on the panel, and a device having a fluid therein and connected to the panel and the housing for restraining the acceleration of the panel to prevent closing the contact members of the relay by the rotary movement of the panel, said restraining device being constructed to permit the panel to remain in any desired position.

7. In a switchboard structure, in combination, a housing, a panel hinged to the housing, a relay mounted on the panel, a device having a fluid therein and connected to the panel and the housing for restraining the acceleration of the panel to prevent closing the contact members of the relay by the rotary movement of the panel, and valve means for adjusting the restraining effect of said fluid to vary the rate of acceleration of the panel, said restraining device being constructed to permit the panel to remain in any desired position.

MARK A. P'FtINGrIJL.

REFERENGES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 765,396 Neuberth July 19, 1904 1,759,649 Lehherz May 20, 1930 2,130,250 Reed Sept. 13, 1938 2,227,970 Hill Jan. 7, 1941