US2295310A

US2295310A - Electric cutout

Info

Publication number: US2295310A
Application number: US385071A
Authority: US
Inventors: Harold M Towne
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1941-03-25
Filing date: 1941-03-25
Publication date: 1942-09-08
Anticipated expiration: 1959-09-08

Description

p 1942- H. M. TOWNE ELECTRIC CUTOUT I Filed March 25, 1941 n w e Emmi o 3% m N mil/Wm mps m m e Z m V. 6 t w B. A a H H Patented Sept. 8, 1942 ELECTRIC CUTOUT Harold M. Towne, Pittsficld, Mass., assignor to General Electric Company, a corporation of New York Application March 25, 1941, Serial No. 385,071

11 Claims.

This invention relates to an electric cutout and more particularly to an electric cutout. suitable for controlling a plurality of circuits and having an expulsion fuse in one of the circuits.

In certain installations such as those of distribution transformers, a primary cutout is usually provided which includes an automatic circuit interrupter such as an expulsion fuse. The cutout is also manually operable for use as a disconnect switch whereby the transformer may be isolated from the line as during servicing operations. Such installations also usually include a lightning arrester or protective gap which may be mounted adjacent to or upon the transformer itself, in which cases it is also desirable to provide a switch 'for isolating the lightning arrester in order that it will not constitute a hazard to the lineman while servicing the transformer. One disadvantage of a separate isolating switch for the lightning arrester is that this switch is frequently, deliberately or inadvertently, left closed by the lineman after the primary cutout has been opened thus unduly exposing himself to accidental contact with parts at line potential.

It is not practical to arrange the fuse in the cirl cuit ahead of the lightning arrester for, in such an arrangement, the fuse would be blown by lightning discharges. It is desirable, therefore, to provide a new primary cutout so constructed and arranged that the arrester can be connected to the line side of the fuse, and when the cutout is manually operated to the open circuit position as a disconnect switch, it will isolate both the transformer and the lightning arrester from the line.

It is therefore an object of the present invention to provide a new and improved electric circuit interrupter for controlling a plurality of circuits and which includes an excess current responsive element for interrupting one of the circuits.

It is another object of the invention to provide a new and improved circuit interrupting device for controlling a plurality of circuits, the device including an excess current protective element such as a fuse for certain of the circuits and merely a pair of switching contacts for controlling other of the circuits.

It is a further object of the invention to provide a new and improved circuit interrupting device so constructed and arranged as to be manually operable for isolating a plurality of circuits, at least one of which is protected by a fusible element contained in the device.

What I consider to be novel and my invention will be better understood by reference to the following description and the appended claims when considered in connection with the accompanying drawing in which Fig. 1 is a front elevation of a circuit interrupter or cutout constructed in accordance with the present invention having portions broken away for the purpose of more clearly illustrating certain details; Fig. 2 is a side crosssectional view of the cutout; Fig. 3 is an end cross-sectional view of the cutout taken along the line 33 of Fig. 1; and Fig. 4 is a view illustrating a typical installation for the cutout of my invention.

The cutout comprises an open front insulating casing II], which, in the present embodiment, is T-shaped as viewed in Fig. 1. In the opposite ends of'the upper or widened portion of the casing l0 are mounted two spaced apart contacts H and I2 having connectors l3 and I4, respectively, for securing thereto the ends of conduc-- tors to be inserted through adjacent openings in the side walls of the casing. Secured in the lower central portion of the casing I0 is a third contact 15 also having a terminal l8 for securing thereto the end of a cable inserted through an adjacent wall opening. The casing is provided with an insulating cover I! upon the inner surface of which is mounted a fuse l8 in the upstanding portions l9 and 20 of insulating material integral with the cover H. The fuse 18 may be of the expulsion type and the cover so mounted upon the casing that it will automatically drop to an opened position upon the blowing of the fuse. As shown, the cover I! is supported by a metal lever 22 which is pivotally connected at 23 to the upstanding portion 23 and which lever is provided with a hook 24 passing over a pivotal pin 25 secured in the lower end of the casing 10. The fuse link conductor 26 is fastened as at 21 to the lever 22 and electrical connection with the contact i5 is completed through the contact finger 28. The cover supporting ar rangement just described is not a part of the present invention but is merely illustrative of one type of a cutout well known in the art and with which my invention may be utilized. For a more complete description of the cover supporting arrangement, reference is hereby made to the Patent 2,081,813 issued May 25, 1937 to Benjamin R. Hermann, and assigned to the General Electric Company, the assignee of the present application. 7

'I'he upper end of the fuse tube I8 is provided with a metal ferrule 3| electrically connected through the cap 32 with the upper end of the enclosed fuse link. The ferrule 3| is electrically engaged by a spring clip 33 mounted on the inner surface of the cutout cover above the upstanding portion l9. Also secured to the inner surface of the cutout cover on opposite sides of the clip 33 is a pair of contact buttons or terminals 34 and 35 through angle brackets 36 as shown more clearly in Fig. 2. The contact buttons 34 and 35 and the spring clip 33 are all connected together by a transversely extending conductor strip 31. The contact buttons 34 and 35 are so arranged that in the closed position of the cover I! they engage with the lower surface of the outwardly extending fingers of the casing contacts H and I2 to effect an electrical connection therebetween. The casing I is provided with a plurality of

insulating barriers

65 and 66 integral with the back wall of the casing and extending forwardly therefrom so as to provide a high leakage path between the respective terminals so as to adequately preclude a fiashover occurring therebetween during the open or disconnected condition of the cutout.

A typical installation of the cutout of the present invention is illustrated in Fig. 4 in which the cutout is shown supported upon the end of an arm 42 which in turn is secured to the bracket 43 provided for supporting a transformer 44 upon the pole 45. A line conductor 46 is connected to one of the upper contacts of the cutout, for example, the contact II through the connector 13 while the other upper contact [2 is similarly connected by lead 4'! to associated apparatus such as the lightning arrester 48. The arrester is shown supported by means of a bracket 49, which, in turn may be secured to the transformer or to supporting bracket 43. The lower cutout contact I is connected by lead 5| to the primary bushin terminal 52 of the transformer 44. Connected in this manner, the upper contacts l I and i2 may be termed the line and lightning arrester contacts, respectively, though it will be obvious from the construction described that these connections may be interchanged. The lower cutout contact l5 may be referred to as the load contact.

In the closed position of the cutout cover, as shown, circuits are established from the line conductor 45 through the cutout line contact I l, the contact button 34, conductor strip 31, through the contact button 35, lightning arrester contact l2, and connection lead 41 to the lightning arrester 48. A load circuit is also established from the conductor strip 3! through the spring clip 33, the fuse l8, lever 22, contact finger 23, load contact l5 and connection 5| to the transformer 44. Thus it will be observed that a simple switch connection is made between the line and lightning arrester contacts H and I2 whereas a fused connection is made between the line and load contacts. Thus a lineman preparing to service the transformer by opening the single cutout device will disconnect both the transformer and the lightning arrester from the line. Servicing operations of the transformer may therefore be carried out with comparative safety.

While I have described my invention as it may be adapted for use in connection with a transformer and lightning arrester installation, other uses for the device will readily occur to one skilled in the art.

Having described the principle of operation of my invention in what I consider to represent a preferred embodiment thereof, it is to be understood that the specific structure shown is merely illustrative and that the invention may be carried out by other means.

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

1. An electric cutout comprising an insulating support, a line contact mounted on said support, a circuit interrupting device mounted on said support and having a terminal movable into engagement with said contact, a second circuit terminal adapted to be electrically connected to an associated apparatus, and means carried by said support conductively connecting said second circuit terminal with said first mentioned terminal, whereby said line contact is connected to said associated apparatus.

2. An electric cut out having a line contact and a load circuit contact, a current responsive circuit interrupter for connection between said contacts, a support including an operating handle for said circuit interrupter and means carried by said support for controlling a second circuit extending from said line contact.

3. In combination with an electric cutout of the type having a pair of contacts and a fusible circuit interrupting device movable into an electrically bridging relation with respect to said pair of contacts, an auxiliary terminal on said cutout and conductor means for electrically connecting said terminal to one of said contacts upon movement of said device to said contact bridging relation.

4. An electric cutout comprising an insulating support, a pair of spaced contacts on said support and a third contact on said support spaced from said pair, a circuit interrupter pivoted on said support with a first end movable into engagement with said third contact and the second end into engagement with one of said pair of contacts, and means carried by said circuit interrupter for conduotively connecting said pair of spaced contacts.

5. An electric cutout comprising an insulating support, at least three spaced contacts carried by said support, a fuse pivoted on said support, one end of said fuse having means for effecting a bridging connection between a pair of said contacts, the other end of said fuse having means associated therewith for connection to the third of said contacts, said last mentioned means being responsive to the blowing of said fuse for disconnecting all of said contacts.

6. An electrical cutout comprising a casing of insulating material, three spaced contacts mounted in said casing, a cover for said casing, a fuse carried by said cover, means connected to one end of said fuse for bridging a pair of said contacts, and means carried by said cover for connecting the third of said contacts to the other end of said fuse.

7. An electric cutout comprising a casing of insulating material, a pair of contacts mounted in a spaced relation in the upper portion of said casing, a third contact mounted in said casing in the lower portion thereof, a cover for said casing, a conductor carried by said cover for bridging said pair of stationary contacts, a fuse carried by said cover, and means for connecting said fuse between said bridging member and said third contact.

8. An electric cutout comprising a casing of insulating material, a pair of laterally spaced apart contacts mounted in the upper part of said casing, a third contact mounted in said casing and spaced below said first pair of contacts, a cover pivotally supported on the lower portion of said casing, a fuse carried by said cover, a bridging member carried by said cover for effecting an electrical connection between said pair of contacts, means carried by said cover for connecting said fuse between said bridging member and said third contact including means responsive to the operation of said fuse for effecting a disconnection of said bridging member from said pair of contacts.

9. An electric cutout comprising a casing of insulating material, spaced apart line and lightning arrester contacts mounted in said casing, a load contact mounted in said casing and spaced from said first mentioned contacts, a cover for said casing, a fuse carried by said cover and operable thereby into electrical connection between said load and line contacts, means carried by said cover for effecting electrical connection between said line and lightning arrester contacts, the removal of said cover automatically effecting disconnection of said line contact from the remaining of said contacts.

10. An electric cutout comprising a casing of insulating material, a pair of laterally spaced apart contacts mounted in the upper part of said casing, a third contact mounted in said casing and spaced from said first pair of contacts, a

cover for said casing pivotally supported on said casing adjacent said third contact, a fuse carried by said cover, a conductor carried by said cover and adapted to be moved into a bridging relation with respect to said first pair of contacts, said fuse being mounted on said cover by means for effecting connection thereof between said pair of contacts and said third contact, and means responsive to the operation of said fuse for effecting the disconnection of said bridging member from said first pair of contacts.

11. An electric cutout comprising a casing of insulating material, spaced apart line and lightning arrester contacts secured in said casing, a load contact secured in said casing in a spaced relation with respect to said first mentioned contact, a cover pivotally supported to said casing, a fuse carried by said cover, a conductor carried by said cover for effecting an electrical connection between said line and lightning arrester contacts, means for connecting said fuse between said conductor and said load contact including means responsive to the operation of said fuse for effecting disconnection of said line and lightning arrester contacts.

HAROLD M. TOWNE.