US2734965A

US2734965A - Combination fuse cutout and loadbreak cartridge

Info

Publication number: US2734965A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

COMBINATION FUSE CUTOUT AND LOADBREAK CARTRIDGE Filed July 11, 1952 R. A. WOOD Feb.' 14, 1956 2 Sheets-Sheet l INVENTOR. Russell H. I/l/Bod B Wm.

filler-nay COMBINATION FUSE CUTOUT AND LOADBREAK CARTRIDGE Filed July 11, 1952 R. A. WOOD Feb. 14, 1956 2 Sheets-Sheet 2 INVENTOR- J W flllorniy United States Patent COMBINATION FUSE CUTOUT AND LOADBREAK CARTRIDGE Russell A. Wood, South Milwaukee, Wis., assignor to McGraw Electric Company, Milwaukee, Wis., a corporation of Delaware Application July 11, 1952, Serial No. 298,359

2 Claims. (Cl. 200-114) This invention relates to a loadbreak to be used principally on an open type fuse cutout for electrical apparatus.

There are numerous occasions when it is necessary to inspect or repair electrical lines and, of course, to do so sometimes requires interrupting the current. A fuse cutout, when opened manually, accomplishes this purpose but it has the disadvantage of drawing an uncontrolled are which may burn its contacts severely or flash to ground.

There are times when the lineman may find it necessary to open a fuse cutout in order to work on the lines but this occasional need hardly justifies expensive loadbreak equipment. If some simple device could be included in the standard fuse cutout that would allow it to be converted into a loadbreak by inserting a loadbreak cartridge whenever desired, it would be a great convenience to maintenance of the electrical lines. And if the loadbreak cartridge could also be adjusted to the various sized cutouts that might be encountered along the line, it would lessen the amount of equipment that the lineman must carry in his truck.

Therefore, it can be seen that if all these measures can be achieved with a device that permits a single adjustable loadbreak cartridge to convert any fuse cutout into a loadbreait which permits opening a circuit without drawing an are or burning the contacts, it would be a great contribution to better electrical service.

One object of this invention is to provide contact means in a fuse cutout wherein a loadbreak cartridge can be inserted whenever it is necessary to open the said fuse cutout, and from which said loadbreak cartridge can be removed for further use.

Another object of this invention is to provide a means of shunting the current that passes through a .fuse cutout while the cutout is being opened.

And another object of this invention is to provide a loadbreak sectionalizing device by which the operator may open the circuit with assurance that arcing will be confined in the loadbreak.

A further object is to provide a means for converting any fuse cutout into a loadbreak device.

Other objects will appear from time to time in the course of the specification and claims.

I illustrate an embodiment of my invention in the ac companying drawings showing the loadbreak cartridge inserted parallel to the fuse cartridge of a standard fuse cutout.

Fig. 1 is a perspective view of a standard fuse cutout I with my loadbreak cartridge inserted.

Fig. 2 is a front elevation of my invention shown more or less diagrammatically.

Fig. 3 is an elevation partly in section of the loadbreak I 2,734,965 Patented Feb. 14, 1956 but it can be seen that my device is adaptable to various types that are in use at present. The precise construction of the fuse cutout shown can be found in Patent No. 2,458,742, issued to W. O. Schultz and assigned to the same assignee as this application.

Referring to Fig. l, the fuse cutout is indicated generally by the. numeral 1 and comprises a mounting block 2, an upper insulating terminal 3 and a lower insulating terminal 4. Extending from the upper terminal 3 is a pair of spring arms 5 which provide a latching and contact means for an upper contact 6 of a fuse cartridge 7. The fuse cartridge 7 is equipped with an eyelet 8 which can be manipulated with a switch stick to open the fuse cutout by pulling the upper contact 6 away from the spring arms 5. The lower end of the fuse cartridge 7 pivots by means of rod extensions 9 on a hinge 10. This rod 9 and hinge 10 form the conductive path to the lower terminal 4. To provide a means for inserting a loadbreak cartridge 11 along side of the fuse cartridge 7, I devised a simple extension from both the upper and lower terminals. The extension from the upper terminal is a conductive clamp 12 that can be attached to the spring arms 5 or some other conductive portion of the upper terminal 3. On the lower terminal, I extend the conductive rod 9 a few inches farther on the same side of the fuse cartridge 7 as the upper conductive clamp 12 extends. The rod 9 has a recessed portion 13 which forms a holding place for a conductive hinge 14 located on the lower portion of the loadbreak cartridge 11. This hinge 14 is a current-carrying part in a manner similar to that of the hinge 10 on the fuse cutout.

The hinge 14 is in fixed position with a sleeve 15. The sleeve 15 is adjustable on the fibre tube portion of the loadbreak cartridge by means of a thumb screw 16 which allows the sleeve 15 to be located at various spots. In this way, the 'loadbreak cartridge can be fitted to various size cutouts. This is shown in Fig. 3, the bottom position is suitable to the 15 kv. cutout, the intermediate position is for the 7.5 ltv. cutout and the top position is for the 5 kv. cutout. Bolt holes at the various stations receive the thumb screw 16 which can be tightened to hold the sleeve 15 with its fixed hinge 14.

The loadbreak cartridge 11 can be seen in Fig. 3. It consists of a fibre tube 17 with a loadbreak mechanism inside. The loadbreak mechanism has a flexible conductor 18 extending through it surrounded by a spring 19 under tension. The flexible conductor 18 ends in a large loop 18a and is fastened conductively to the adjustable fixed hinge 14 by some fastening means. On its upper end the conductor'has a head 20 with a beveled underside 21. Above the head portion 20 is a follower tube 22 made of some non-conductive material such as plastic.

A conductive sleeve 23 with an inner shoulder 24 encases the upper portion of the fibre tube 17. A tripping device 25 holds the underside 21 of the conductor head 20 against the inner shoulder 24 thus forming a conductive path to the clamping device 12 attached to the upper terminal of the fuse cutout.

The tripping device 25 has an eyelet 26 attached and when this eyelet 26 is pulled downward on its pivot 27, the tripping device moves away from the underside 21 of the conductor head 20. The conductor then is free to respond to the spring tension 19 and drops downward in the fibre'tube 17 breaking the circuit.

The upper contact and the lower contact for the loadbreak cartridge will only carry a full load momentarily. The loadbreak cartridge will be in operation for a minute or two which means that the contact can be built of relatively light material.

If the lineman wishes to open a fuse cutout either for inspection purposes or to repair some part he can take a loadbreak cartridge 11 and insert the lower fixed hinge 14 over the auxiliary hinge 13 at the bottom of the cutout and slide the upper contact within the auxiliary clamping contact 12 at the upper end of the cutout. This provides a parallel path for the current to flow from the top contact to the lower contact.

With two parallel lines carrying the current between the two terminals of the fuse cutout, the cutout can be moved to its open position, indicated by the dash-dot lines of Fig. 1. Arcing will not occur when the upper contact is opened because the current is flowing through the loadbrealt cartridge. The loadbreak cartridge can then be tripped by pulling the eyelet 26. This will release the conductor head 20 from contact with the shoulder 24 allowing it to drop downwardly in the fibre tube 17 and the follower non-conductor tube 22 to move into its place. By breaking the current wtihin the fibre tube, no flashover occurs external thereto.

After the current has been broken within the loadbrealt cartridge, the loadbreak cartridge can be removed from its clamp and hinge. The follower tube 22 can be pulled outwardly until the tripping device 25 catches the underside 21 of the conductor head 20 again. The loadbreak cartridge is then reset for future loadbreak use.

After the necessary inspection or repair work is completed, the circuit can be re-energized by merely closing the fuse cutout portion of the device.

The imptortant feature of this device is that it is not necessary to have the loadbreak cartridge mounted continuously to achieve a combination unit. It is possible with a single loadbreak cartridge to disconnect all three cutouts at a sectionalizing point by repeating the above procedure on successive cutouts. And with the adjustable feature in the lower contact portion, the same loadbreak cartridge can be used on various sized cutouts.

Thus, it can be seen that with this simple inexpensive clamping and hinge attachment to the terminals of a fuse cutout, better and faster service can be maintained by the linemen. Repairs can be made without delay. And, furthermore, this greater service can be provided with less equipment than formerly.

Iclaim:

1. In a combination fuse cutout and load-break device, a mounting base having spaced insulators, terminals supported by said insulators, one of said terminals having spaced bearing supports and the other terminal having a latching means and a clamping means spaced therefrom, a fuse cutout normally electrically connecting said terminals and having a bearing means mounted in said hearing supports and extending laterally from one end of said cutout to a point beneath said clamping means, said cutout held by said latching means, a load-break cartridge including a fiber tube having therein a load-break mechanism normally latched in circuit closing position, a sleeve on said load-break cartridge having a hinge pivotally supporting said cartridge on said bearing means, the opposite end of said cartridge engaged by said clamping means, whereby said cutout may be moved to open position without arcing and said load-break mechanism may be subsequently tripped to open the circuit within said cartridge under load.

2. In a combination fuse cutout and load-break device, a mounting base having spaced insulators, terminals supported by said insulators, one of said terminals having spaced bearing supports and the other terminal having a latching means and a clamping means spaced therefrom, a fuse cutout normally electrically connecting said terminals and having a bearing rod mounted in said bearing supports and extending laterally from one end of said cutout to a point beneath said clamping means, said cutout held by said latching means, a load-break cartridge including a fiber tube having therein a load-break mechanism normally latched in circuit closing position, sleeve means adjustably slidable on said load break cartridge, said sleeve means having hinge means pivotally supporting said cartridge on said bearing rod, the opposite end of said cartridge engaged by said clamping means, whereby said cutout may be moved to open position without arcing and said load-break mechanism may be subsequently tripped to open the circuit within said cartridge under load.

References Cited in the file of this patent UNITED STATES PATENTS 1,393,344 Conrad Oct. 11, 1921 1,899,915 Matthews et al. Feb. 28, 1933 2,189,764 Schultz Feb. 13, 1940 2,637,795 Hubbard May 5, 1953