US2267167A

US2267167A - Fuse construction

Info

Publication number: US2267167A
Application number: US316147A
Authority: US
Inventors: Ralph R Pittman; Carroll H Walsh
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-01-29
Filing date: 1940-01-29
Publication date: 1941-12-23
Anticipated expiration: 1958-12-23

Description

Dec. 23, 1941. R. R. PITTMAN ETAL FUSE CONSTRUCTION Filed Jan. 29, 1940 55...; I ll:

INVENTORS 96 Q (2W4 M M Patented Dec. 23, 1941 FUSE CONSTRUCTION Ralph E. Pittman and Carroll B. Walsh,

Pine Bluff, Ark.

Application January 29, 1940, Serial No. 316,147 8 Claims. (Cl. 200-111) This invention relates generally to fuse switches, and particularly to high voltage fuse switches commonly employed for connecting electrical apparatus to distribution circuits.

Among the objects of the invention may be noted the provision of a resilient mounting for the fuse link of the switch in which the switch is in the open circuit position, together with means for moving the fuse link to and establishing the fusible element in the closed circuit position, in which the fuse link is maintained under tension when unfused; and the provision of means for testing the connected circuit by temporarily connecting the fuse link in the circuit without moving it to the normal closed circuit position. Other objects will be obvious, or in part pointed out hereinafter.

The invention comprises the elements and combinations thereof, features of construction, and arrangement of parts to be exemplified in the description to follow, and the scope of the invention will be indicated in the accompanying claims.

Fuse switches heretofore in general use which have embodied atensioned fuse link have been objectionable for the reason that the insertion of fuse link completed the circuit, while the link itself must pull apart upon fusing in order to interrupt a relatively high current in the circuit. This construction was such that an operator was required to look directly at the device in order to insert the link, with the probability that the fuse link might be blown upon completion of the circuit. The intensely bright are attending the fusing of the link was not only a hazard to the eyes of the operator, but flying fragments incident to the fracture of the more or less frangible wall of the fusible element housing were also dangerous.

The present invention embodies a simple arrangement for inserting the fuse link without completing the circuit, and means for testing the connected circuit by an operator s positioned as to be exposed to no hazard before finally establishing the fuse link in the normal closed circuit position.

In the drawing: Fig. 1 is a side elevational view of the device; and Fig. 2 is a front elevational view of the fuse link, shown partly in section, together with fragmentary portions of the fuse link mounting members.

Similar reference characters indicate corresponding parts in the figures of the drawing.

Referring first to Fig. 1, the longitudinally extending insulator II is provided near its midpoint with a mounting bracket Hi, the latter being only partly shown. The upper end of the insulator l l is encircled by a portion of the resilient conducting switch arm l8, which is clamped in position on the insulator H by means of the cap screw 26 in cooperation with the line terminal clamp I3, and extends outwardly therefrom first in the form of a loop 40, to supply additional resilience, thence outwardly, downwardly and upwardly to provide the depression 28, and terminates at'its outermost end in the form of an upwardly turned hook 29. The line terminal clamp also extends upwardly to a point above the resilient conducting member l8, and is provided with a line terminal connector I for the purpose of electrically connecting the line conductor l2 to the resilient conducting member If.

At the lower end of the insulator II is rigidly attached, in any suitable manner, as by the encircling band 25, the lower fuse link supporting member 23, which is of non-resilient construction, and which extends outwardly from the insulator H in substantially parallel relationship with the resilient member [8. The outermost end of the member 23 is formed as a downwardly turned hook 24, and the latter is positioned somewhat nearer the insulator H than is the de' pression, or fuse link engaging portion 28, of the resilient member l8. At some convenient point near the insulator H, the lower fuse link supporting member 23 is provided with the load terminal l6 and the connector H, the latter two elements cooperating to establish electrical connection of the load conductor I5 to the lower fuse link supporting member 23.

In addition to the members at the respective ends of the insulator II, the intermediate fuse link supporting member i9 is also rigidly mounted, in any suitable manner, on the insulator H, at a point therebetween and adjacent to the member l8 but insulated from both of the end members I8 and 23 respectively. The intermediate member 19 extends outwardly in approximately parallel relationship with the end members l8 and 23, and is preferably of the same length as the latter. The outermost end portion of the intermediate member I! is formed into an upwardly turned hook 20, across the opening of which is mounted the resilient tensioning member 2|, the latter being mounted on the support 22 and arranged to resist deflection in a downward direction.

The fuse link 21, shown in detail in Fig. 2, includes the frangible tubular casing of insulat ing material 30, the respective ends thereof being closed by the metal plugs 3| and 32, by means of cooperating threads on the respective members. A fusible element 33 spans the plugs 3| and 32 within the tube 30, being conveniently secured at its respective ends by soldering. Extending endwise from each end of the tube 30, and fastened respectively to the plugs 3| and 32, are the flexible connecting

wires

34 and 35, the outer ends being fastened respectively to the terminal members 36 and 31. The latter are formed into closed loops, conveniently circular in section, one end of wire forming the loops extending respectively above and below the terminal members 36 and 31 and being bent to form the hooked

portions

38 and 39, the opening of each of the hooked portions facing toward the remaining portions of the fuse link.

To explain the manner of operation of the device, it is first assumed that no fuse link is mounted on the device, and that it is desired to connect the terminals through a fuse link. Through manipulation of the fuse link by a suitable insulated tool, the loop 36 may be placed on the resilient member 2| of the hook 20. The tool is then engaged with the lower hook 39 of the fuse link, the link pulled downwardly against the bias of the spring 2!, and the lower loop 3i engaged with the lower hook 24. The fuse link and the resilient switch arm 3 now occupy the position shown by the dashed lines of Fig. 1. It may be noted that in this position the terminals I3 and I6 are not connected through the fuse link.

The hooked portion 29 is next engaged with the insulated tool, and the member I8 is preferably pulled down until it contacts some point on the top surface of the hooked portion 38 of the fuse link 21. This is a test proceeding used to determine the condition of the connected circuit, and may be readily done while the operators eyes and face are averted, and while the operator is at a safe distance from the fuse link should the latter explode in response to excessively high abnormal current due to a defective or faulty connected circuit.

If the test indicates that the fuse link will not be blown when the terminals are connected, the member I8 is moved slightly laterally and downwardly to a point from which it may enter the hooked portion 38, and the member l8 then released. The hooked portion 38 then slides outwardly along the downwardly sloping portion of the member I8 until it is seated in the fuse link engaging depression 28. This is the normal operating arrangement of the elements when the device is in service, the member [8 having cooperated with the fuse link 21 to effect the switching of the device from the open circuit position to the closed circuit position, or to effect the moving of the fuse link from the open to closed circuit positions; in the latter position the fuse link being tensioned by the tendency of the switch arm l8 to return to the relaxed position indicated by the dashed lines.

Upon the passage of sufiicient current through the fuse link while it is in the normal service position, the frangible cartridge 30 is fractured, and the elements of the fusible portion of the fuse link pulled apart under the bias of the resilient switch arm l8. In addition, the looped portion 31 falls by gravity from its position on the lower fuse tube support 23. These events all combine to assure prompt circuit interruption, as well as easily visible indication that the fuse link has been blown.

, In the event it is desired, for any reason, to remove the fuse link from the normal service position, this may be readily accomplished by disengaging the loop 31 from the lower hook 24 by pulling downwardly and outwardly the lower hooked portion 39 of the fuse link 27, and then unhooking the link from the member l8.

From the above description, it will be apparent that the several objects of the invention are simply and economically accomplished. It is obvious that changes and modifications may be made therein without departing from the spirit and scope of the invention, and it is intended that our description shall be interpreted as illustrative rather than limiting.

We claim, as our invention:

1. A fuse construction for use with an electric circuit comprising an insulator, a resilient conducting member mounted on said insulator, a fuse link removably supported at its respective ends on said insulator in an initial position out of said circuit, and means responsive to a predetermined movement of said conducting member for bodily moving said fuse link from the initial position to a final position in which said fuse link is connected in said circuit.

2. A fuse construction comprising insulating means supporting spaced terminals and fuse link supporting means including a fuse link supporting member which is insulated with respect to said terminals, a fuse link mounted on said fuse link supporting means, a resilient conducting member mounted on said insulating means and electrically connected to one of said terminals, and means responsive to a predetermined movement of said conducting member for removing said fuse link from said supporting member and electrically connecting said terminals through said fuse link.

3. A fuse construction comprising insulating means supporting spaced insulated terminals and fuse link supporting means including a member which is insulated with respect to said terminals,

a fuse link mounted on said supporting means and so arranged that said terminals are not electrically connected through said fuse link, a resilient conducting member mounted on said insulating means and electrically connected to one of said terminals, and means responsive to a predetermined movement of said conducting having an open and a normal operating closed position in series circuit relation with said fuse link, said elements including a portion of said fuse link and a resilient switch arm mounted on said insulating means, the arrangement being such that said switch arm'tensions said fuse link only when said switch is in the normal operating closed position.

5. A fuse construction comprising insulating means, an upper resilient switch arm, an intermediate fuse supporting member, and a lower fuse supporting member all mounted in spaced insulated relation to each other on said insulating means, line and load terminals electrically connected respectively to said switch arm and said lower fuse supporting member, and means for resiliently supporting a fuse link on said fuse supporting members in insulated relationship with said switch arm, said fuse link having its upper end portion constructed and arranged to cooperate with said switch arm in response to a predetermined movement thereof so as to effect removal of said fuse link from said intermediate supporting member and electrically connect said line and load terminals through said fuse link.

6. A fuse construction comprising an insulator, an upper resilient switch arm and a lower rigid fuse link supporting member mounted at the respective ends of said insulator, an intermediate fuse supporting member mounted in spaced insulated relation on said insulator between said switch arm and said lower fuse supporting member, and means for resiliently mounting a fuse link on said fuse supporting members in insulated relationship with said switch arm, said fuse link having its upper end portion extending above said intermediate fuse supporting member, said upper end portion being bent to provide a hook arranged to cooperate with said switch arm in response to a predetermined movement thereof so as to effect removal of said fuse link from said intermediate supporting member and electrically connect said switch arm and said lower fuse supporting member.

7. A fuse construction comprising an insulator, an upper resilient switch arm and a lower rigid fuse link supporting member mounted at the respective ends of said insulator, an intermediate fuse supporting member mounted in spaced insulated relation on said insulator between said switch arm and said lower fuse supporting member, and means for resiliently mounting a fuse link on said fuse supporting members in insulated relationship with said switch arm, said fuse link having its upper end portion extending above said intermediate fuse supporting member, said upper end portion being bent to provide a hook arranged to cooperate with said switch arm in response to a predetermined movement thereof so as to effect removal of said fuse link from said intermediate supporting member and position said fuse link so as to span said switch arm and said lower fuse link supporting member.

8. A fuse construction comprising an insulator, an upper resilient switch arm and a lower rigid fuse link supporting member mounted at the respective ends of said insulator, an intermediate fuse supporting member mounted in spaced insulated relation on said insulator between said switch arm and said lower fuse supporting member, and means for resiliently mounting a fuse link on said fuse supporting members in insulated relationship with said switch arm, said fuse link having its upper end portion extending above said intermediate fuse supporting member, said upper end portion being bent to provide a hook arranged to cooperate with said switch arm in response to a predetermined movement thereof so as to effect removal of said fuse link from said intermediate supporting member and tension said fuse link between said switch arm and said lower fuse link supporting member.

RALPH R. PI'I'I'MAN. CARROLL H. WALSH.