US2290709A - Circuit interrupter - Google Patents

Description

July 21, 1942. ,H. L. RAWLINS cmcun' INTERRUPTER Filed Sept. 20, 1959 INVENTOR flerberfLfiaW/ms.

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Patented July 21, 1942 CIRCUIT INTERRUPTER Herbert L. Rawlins, Wilkinsburg, Pa., assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa.., a corporation of Pennsylvania Application September 20, 1939, Serial No. 295,726

13 Claims.

This invention relates generally to circuit interrupting devices, and more specifically to manually operable automatic interrupter devices.

It is an object of my invention to provide a circuit interrupting device which embodies novel means for physically disconnecting the device from its associated circuit after it has performed an interrupting operation.

It is a further object of my invention to provide a circuit interrupting device with novel signalling means to indicate the performance of a circuit interrupting operation.

Another object of my invention is to provide a circuit interrupting device which embodies novel means for physically disconnecting the device from its associated circuit in response to an interrupting operation thereof, which means also serves as a signal to indicate the occurrence of such an operation.

. Another object of my invention is to provide a circuit interrupting device enclosed in a housing with indicating means visible from outside the housing only after the device has performed an interrupting operation.

These and other objects of my invention will become more apparent upon consideration of the following specification in connection with the attached drawing, in which:

Figure 1 is a vertical sectional view through a fuse housing, showing a fuse mounted therein the lower end of the device shown in Figur 1,

but showing'the door and fuse in an open position.

Although I have illustrated my invention in connection with an enclosed fused cut-out, it should be understood that this particular fuse mounting and terminal structure, obviously, could be used, without an enclosing insulating housing.

In the particular embodiment of my invention shown on the drawing, there is provided an insulating housing 2 made of any suitable insulating material, such as porcelain, glass, or a molded insulation material. The housing 2 has a rear wardly projecting annular skirt 3 and a central, rearwardly projecting, integral portion having spaced interiorly threaded apertures 4, for the reception of threaded anchor pins 6, for supporting the housing from a cross-arm, or any other desired support, as by a. bracket 8 bolted thereto. The housing has open front and bottom portions and is provided interiorly thereof with an upper contact member I, having an upwardly extending portion l2, which carries a lead wire receiving portion l4, in which a lead wire to the cut-out may be inserted. and secured by a setscrew I6. The upper contact member ID further includes integral, spaced, forwardly-extending contact arms ll (only one of which is shown) having their outer ends curved and then flared outward- 1y, to releasably and resiliently engage the upper terminal 22 offuse 20. Located intermediately of the inner rear wall of the housing 2 is an integral, transversely extending, insulating barrier member 24. A lower contact member 26 is provided in the lower part of the housing and includes a lead wire receiving member 28, in which a lead wire for the device may be inserted, and secured therein as by setscrews 30. The lower contact member has at its forward lower side, an

integral contact portion 32 adapted to be en gaged by the lower terminal of the fuse 20. The contact members I0 and 26 may be secured in the housing in any desired manner. Thus, for example, the contact members may have integral side extensions received in apertures in the side walls of the housing, either being molded or cemented therein, or the upper contact member It! may have integral resilient strips l9 struck out from the contact arms l8 and being receivable in closed ended slots in the side walls of the housing, to releasably secure the contact member position.

The door 31 for the housing includes a pair of arcuate fuse retaining members 34 (only one of which is shown) having a pin 36 removably engaged in their outer ends for retaining the fuse in position on the door. The door further includes at its upper, outer side, an integralapertured handle portion 38 adapted to be manually operated or for operation by a hook-stick operating member. The door further includes an inwardly and outwardly extending, integral flange 40 extending from the upper and side edges thereof for engagement with an abutment 42,

inwardly of the open side of the housing. At its lower end, the door is provided with a pair of spaced, inwardly extending integral flanges 44, and through which extends a door pivot pin 46, with the outer ends of the pivot pin extended beyond flanges 44, and adapted to be received in slots 48 provided in the housing walls so that the door may be removed ii desired.

It will be noted that fuse is mounted on door 31 for movement therewith into and out of engagement with upper contact arms it and these arms serve to secure the fuse in circuit closing position, and this in turn secures the door in a closed position. It should also be apparent that the fuse being secured to the door, when the door is moved to open position, it may be entirely removed from the housing merely by lifting it upwardly and outwardly to remove the door pivot pin 48 from slots 48, thus, enabling convenient refusing, when necessary.

The fuse 20 is of the well-known expulsion type, and includes a tubular casing of insulating material, preferably of fiber, or at least having a lining of fiber or other material capable of evolving an arc extinguishing gas, when in proximity to an electric arc, and includes further an upper terminal 22, previously described, and a top removable cap 50 having a knurled head for securing the upper end of a fuse link to upper terminal 22. The lower end of the fuse link extends out of the opening of the lower end of fuse tube 2! as shown at 52, and is secured to a movable fuse terminal member 54, as" by a knurled nut 56. The movable fuse terminal 54 is movably supported and guided by a terminal supporting link 58, which is of general U-shape in form, with its bight portion extending through an elongated aperture 60 in one end of the movable terminal 64, and its leg portions turned outwardly as at 6|, to be pivotally received in apertures provided in the inner sides of door flange portions 44. A pin 64 is secured to, and between the door flange portions 48, and provides a support for a coil spring 62, the intermediate coiled portion of which is coiled about pin E i, and one end of the spring is secured to one of the flange portions 44 as at 66, and the other end of the spring extends upwardly and inwardly as viewed in Fig. 1, and is pivotally secured to fuse terminal 54 adjacent elongated aperture 60, as at 68.

In the open position of the door, as shown in Fig. 4, movable fuse terminal 54 is supported by fuse link 52 at one endthereof, and by fuse supporting member 58 at its other end, with the spring 62 maintaining these parts in engagement and continuously urging the terminal in a direction away from fuse tube 2|. As the door moves to closed position, upper fuse terminal 22 is received between contact arms l8, and the lower movable fuse terminal engages by a raised contact portion 55 thereof, fixed contact portion 32, and is moved against the action of spring 62 to bring the outer end of terminal supporting link 58 out of engagement with the end of elongated aperture 60. It will be noted that the connection between movable terminal 54 and terminal supporting link 58 is, in effect, a lost motion connection, to enable support of movable terminal 54 by terminal supporting link 58, when the door is in an open position, while at the same time, allowing contact of the movable terminal with fixed contact portion 32 under the full pressure of the terminal spring 62.

Upon the passage through the circuit of currents above a predetermined value, corresponding to the rating of the fuse link 52, the fuse link will part, and hence, will no longer supportthe lower end of movable terminal 54. The terminal spring 62 then is free to move terminal 54 in a downwardly direction, and'in effect, cause a pivotal motion about fixed contact portion 32,

as viewed in Fig. l, which will enable the other end of movable terminal 54 to withdraw the lower portion of the fuse link from the fuse tube, and, at the same time move movable terminal E i bodily out of engagement with fixed contact portion 32, to the position shown in Figure 2, this movement being guided and restrained by terminal supporting link 68.

It should be apparent from the foregoing, that my invention discloses a form of indicating cutout in which the door remains closed when the fuse is blown, and the lower fuse terminal 54 under the action of terminal spring 62, drops out of the housing. This action provides a positive indication of the operation of the cut-out, and at the same time inserts a definite air gap into the circuit that eliminates leakage currents. This is accomplished without moving or exposing the fuse tube to the weather.

It should also be noticed, that fuse link 52 is under a relatively small strain in the normal position'of the device, since it sustains but a small portion of the force exerted by terminal spring 52 when in the closed position, because of the relatively great distance between the point of engagement of terminal spring 62 with terminal 54, and the point of engagement of fuse link 52 with terminal 54.

It is thus apparent that I have provided a fuse cut-out having relatively simple but eflicient means for indicating when the device has operated to open its associated circuit, without requiring any exposure of the fuse or contact parts of the device.

Having described a preferred form of my invention in accordance with the patent statutes, I do not wish to be limited to this particular embodiment inasmuch as it will be obvious, particularly to persons skilled in the art, that many changes and modifications may be made in this particular structure without departing from the broad spirit and scope of my invention. Therefore, I desire that my invention be given the broadest possible interpretation, and be limited only by what is expressly stated in the following claims.

I claim as my invention:

1. In a circuit interrupting device, interrupting means adapted to automatically interrupt currents of a predetermined value and having a resiliently-biased movable terminal adapted to engage a contact, said terminal being supported on a pair of spaced pivoted link members so as to be movable in response to an interrupting operation of said means, away from said contact.

2. In a circuit interrupting device, interrupting means adapted to automatically interrupt currents of a predetermined value and having a spring-biased movable terminal supported from said means by a pair of spaced pivoted link members so as to be movable with the interrupting means into and out of engagement with a contact, and so as to be movable away from said contact in response to an interrupting operation of said means.

3. In a circuit interrupting device, means for automatically interrupting currents of a predetermined magnitude, a housing therefor having a lower opening, and means movable in response to a circuit interrupting operation of said interrupting means, to project through said opening, said last named means being supported in said latter position, by a link pivoted thereto and to a supporting member.

4. In a circuit interrupting device, means for automatically interrupting currents of a predetermined magnitude, a housing thereforhaving an opening, a terminal for said interrupting means engageable with a contact in said housing,

and said terminal movable in response to a circuit interrupting operation of said interrupting means in a direction away from said means to project through said opening.

5. In a circuit interrupting device, means for automatically interrupting currents of a predetermined magnitude, a housing therefor having an open bottom, and one side a door for said open side and provided with means for releasably supporting said interrupting means, a contact in said housing positioned to be engaged by a movable terminal of said interrupting means when the door is moved to closed position, said terminal being movable in response to a circuit interrupting operation of said interrupting means away from said contact and through the open bottom of said housing, to disconnect the interrupting means from its associated circuit and provide a readily visible indication thereof.

6. In a circuit interrupting device, a housing having a door, a contact in the housing, means on the door for releasably supporting current interrupting means, said current interrupting means having a movable terminal positioned to engage said contact when the door is closed and movable with a compound motion relative to the interrupting means and housing in response to an interrupting operation of said interrupting means to disconnect the interrupting means from the circuit and project from the housing.

7. In a circuit interrupting device, a housing having a door, a contact in the housing, means on the door for releasably supporting current interrupting means, a terminal for said interrupt-' ing means supported at spaced points by said contact and said interrupting means, respectively, resilient means effectively engaging said terminal at a point spaced from said supporting points and arranged to continuously urge the terminal into engagement with said contact, and, upon an interrupting operation of said interrupting means, and consequent release of said interrupting means terminal support, to move said terminal away from said contact to provide an air gap in the circuit.

8. In a circuit interrupting device, a housing having a door, a contact in the housing, means on the door for releasably supporting current interrupting means, a terminal for said interrupting means supported at spaced points by said contact and said interrupting means, respectively, resilient means effectively engaging said terminal at a point spaced from said supporting points and arranged to continuously urge the terminal into engagement with said contact, and, upon interrupting operation of said interrupting means and consequent release of said interrupting means terminal support, to move said terminal away from said contact to provide an air gap in the circuit, and a supporting link movably engaging said interrupting means and terminal for supporting said terminal when it is out of engagement with said contact.

9. In a circuit interrupting device, a fuse holder including a fuse link and a movable terminal therefor, a contact adapted to be engaged by said terminal, said terminal being supported at spaced points by said contact and fuse link, respectively, and resilient means engaging the terminal for urging it into engagement with said contact, and, upon blowing of said fuse link and consequent release of said interrupting means terminals support, to move the terminal relative to said support and away from said contact to indicate operation and provide an air gap in the circuit.

10. In a circuit interrupting device, a fuse holder including a fuse link and a movable terminal therefor, a contact adapted to be engaged by said terminal, said terminal being supported at spaced points by engagement of said contact and fuse link, and resilient means engaging the terminal and holder for urging the terminal into engagement with said contact, and, upon blowing of said fuse link, to move the terminal relative to said support and away from said contact to indicate operation and provide an air gap in the circuit, another supporting means between the terminal and holder, and adapted to enable the terminal to move with the holder into and out of engagement with said contact, and to support the terminal from the holder in the blown position of the terminal.

11. In a circuit interrupting device, interrupting means adapted to automatically interrupt currents of a predetermined value and having a movable terminal adapted to engage a contact, said terminal being supported on a pair of spaced pivoted link members one of which is resiliently-biased so as to be movable in response to an interrupting operation of said means away from said contact.

12. In a circuit interrupting device, interrupting means adapted to automatically interrupt currents of a predetermined value and having a resiliently-biased movable terminal adapted to engage a contact, said terminal being supported on a pair of spaced pivoted link members so as to be movable in response to an interrupting operation of saidmeans, away from said contact, and one of said link members having a lost motion connection to normally permit said terminal to be resiliently biased into engagement with said contact.

13. In a fuse, a housing having an open side and bottom, a door for said open side of said housing, a fuse holder mounted on said door for movement therewith into and out of said housing, a contact in said housing, a terminal for said fuse holder adapted to engage said contact at least when said door is in closed position, a pair of spaced pivoted links movably supporting said terminal from said door for downward movement relative to said contact and out through the open bottom of said housing, and fusible means in said holder normally maintaining said terminal in a position to engage said contact, but effective to release said terminal for said downward move-

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