US2269992A - Electric switch - Google Patents

Description

E. S-CHEUERMEYER 2,269,992

ELECTRIC SWITCH Filed June 3, 1941 Jan. 13, 1942.

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Scheuevme er; by K uMlMq His Attorney.

Patented Jan, 13,-

Emil Scheuermeyer, Upper Darby Pa., assignor to General Electric Company, a corporation of New York Application June 3, .1941, Serial No. 396,424

. Claims. (01.200-166) The present invention relates to electric switches, and more particularly to improvements.

in construction of switches of the kind employable as disconnecting devices and havinga switching element or blade pivoted for swinging movement to and from a closed position between.-

relatively stationary terminal contacts.

- It is common to provide some means for limiting or arresting the opening swinging movement of the switching element in such devices, and for holding the switching element in a predetermined position such as, for example, a position in which the switching element is readily engageable by consider to be novel and my invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawing wherein:

Fig. 1 shows, in side elevation, an exemplary form of disconnecting switch device embodying my invention; Fig. 2 is an enlarged side elevation, partially in section, showing the details of the hinge. mechanism at the lower end of the device of Fig. .1 but in an opened position thereof; Fig. 3 is an exploded view showing, in perspective, the details of construction of certain of the a switch hook or other operating tool for removal of the element from the switch support. Fixed solid stops are used for this purpose in some forms of disconnecting switch devices. Resilient bufiers, in the fomi of spring strips, also have been proposed for the purpose. However, in any case where a switching element of considerable size or weight is employed, there is danger of breakag of the switching element or its support if the switching element is allowed to swing freelyinto engagement with a solid stop. The danger of breakage of the switching element by engagement with a solid stop likewise is present in the case of a disconnecting device employing a fused-switching element wherein the fuse holdparts of the mechanism shown in Figs. 1' and 2;

and Fig. 4 is a fragmentary view of one portion I of the structure illustrating a second embodiment of the invention.

As will be evident from the ensuing description, various features of the present invention are, subjectito modification and are suitable for er includes a casing constructed of glass, porcelain, or other frangible material. The spring strip form of resilient bufier may be unsatisfactory for the reason, among others, that it is dimensions, which has the desired resiliency and at the same time is capable of efiectively arresting and accurately positioning a large or heavy switching element.

employment in other forms of switch devices. Hence the embodiment shown in the drawing is for purposes of illustration only. In this embodiment the fuse support includes two insulators, l0 and I I, disposed in spaced relationship and bolted or otherwise securedat one end to a suitable.

base. on the outer end of the upper insulator, l0, there is supported a terminal and contact assembly including a terminal plate l3 having. an upwardly projecting extension to which electric line conductors or leads may be secured by clamping devices ll. A contact I5 is rotatably supported on a pin l6 carried by a bracket l1 diflicult to provide vaspring strip of practical It is one of the objects of the present invention to provide, in a disconnecting switch support, a mechanism which is capable of arresting the movement of a switching element and of pre- I venting shock of impact to the switching element or the switch support.

The invention also has for one of its more specific objects the provision of a switch support including a motion arresting means for the switching element as it swings to open position, the eiiectiveness of which means increases gradu ally as the element continues to move in the opening direction.

A further object is the provision of an improved mounting arrangement for disconnecting switch devices and the like of a simple, compact and economical construction.

Other objects'and the details of that which I mounted on terminal plate l3. One or more springs 20 serve to bias contact i5 forrotation in a clockwise direction, as viewed in the drawing, and an adjustable stop screw 2| is provided on the. lower end of the contact for limiting its rotation. A-flexible braided conductor 22 insures good electric connection between the contact and terminal plate l3. The contact has two outwardly projecting arms 23, one of which may be seen in the drawing, for receiving therebetween and engaging'the upper end of a switching element 24.

. On the outer end of lower insulator ll,there is mounted a terminal plate 25 which, similarly to terminalplate l3, has an extension to which line conductors or leads may be secured by clamping devices I. The upper part of terminal plate 25 is adapted to serve as a hinge support and has two integrally formed bracket arms 26 disposed in horizontally spaced relationship. Extending horizontally between the bracket arms 26 is a hinge bolt 21 having a hinge nut 28ccoperatively threaded thereupon. One end of however, than the holes 32, are uniformly spaced in a circle about the hinge bolt 21 in the outer surface of the bracket arm. The holes 33. are tapped for receiving a screw 34 extending through one of the holes 32 of the vemier disk 3i to secure the latter over the end of the hinge bolt 21 and to the bracket arm. With the hinge bolt 21 thus held fixed as regards the bracket, rotation of the hinge nut 28 will cause the latter to travel along the bolt by virtue of the threaded engagement therewith. Arranged around one end of the hinge bolt 21 between the end of the nut 28 and the adjacent bracket arm, is a com' pression member 36 which, for example, may be a spring washer of a well known form. In a modification shown in Fig. 4, the spring washer 36' is arranged on thefiouter side of the bracket arm beneath the bolt head 21'. It will be readily apparent that rotation of the hinge nut 28 about the hinge bolt 21 in the clockwise direction will effect a compression of the spring washer which will gradually increase the frictional resistance of the hinge nut 28 to the turning moment.

The present invention may be embodied to advantage in switch supports for mounting of various forms of switching elements or blades, and it is not intended therefore that the invention be limited to any one particular form of switching element or blade. However, the illus trated exemplary switch support is specially suited'for the mounting of switching elements embodying fuse devices having cases constructed of cooperatively fitting over the hinge nut 28 and supporting the fuse device thereon. 'Inorder that the hinge nut 28 will be turned by swinging movement of the fuse device, a pair of opposite surfaces of the nut are squared as indicated at 48, the hook 41 being correspondingly slotted for cooperatively fitting over the hinge nut with a relatively close fit. The hook 41 is so shaped as regards the spacing between the back surface of theterminal plate 25 and the hinge nut 28 that the fuse device may be removed and attached to the support only in the wide opened position thereof, as indicated in Fig. 2; secured to the back surface of the hook is a leaf spring 49 ,which in the closed position of the switching element makes firm contact with the adjacent surface of the terminal plate.

The operation of the switch support described should be obvious. When the switching element glass, porcelain, or other frangible materiah,

Such a fuse device is indicated at 24 on the drawing. This fuse device may, for example, be of the form shown in United States Patent 2,188,816, issued January 30, 1940, to W. K. Rankin, and assigned to the General Electric Company, the assignee of .the present invention. Fuse devices of the form shown in the Rankin patent are of considerable size and weight, particularly when designed for high current interrupting ratings. They include a fusible element, and insulating supports therefor, embedded in a body of-sand or granular quartz which is contained in a tubular glass casing. Opposite ends of the glass casing are closed by metallic terminal ferrules 38. and. 39, respectively, which serve for connection of the fuse unit in an electric circuit.

For mounting the switching element or fuse device 24 on the previously described switch support, appropriate fittings are applied on'the up-.

per and lower ends, respectively, of the fuse device. The fitting on the upper end of the fuse device comprises a metallic contact ring 4| clamped on the upper terminal ferrule 38 and having suitable contact surfaces for engagement wardly extending portion defining a hook 41 for is moved upwardly, the nut 28 will be retracted from the compression member. Since movement in the closing direction will be relatively free, particularly near the end of the closing stroke, false'closing of the switch device because of binding at the pivotal end will be substantially preeluded. By pulling downwardly on the operating member, as with a switch hook inserted through the eye 43, the upper contacts may be separated and the fuse device permitted to swing outwardly. Rotation of the hinge nut 28 will cause a compression of themember 36 gradually increasing the frictional resistance to the turning moment. By suitable adjustment of the hinge bolt 21 with the vernier disk 3|, the compression of the spring washer can be so timed as regards the angle of rotation of the switch device 24 that the latter device may be arrested in substantially any predetermined desired opened position. It will be observed that the straight outerend 5| of the hook 41 is shaped so as to engage with the adjacent surface of the terminal plate 25 in the wide opened position of the switch device 24 providing an ultimate stop therefor.

Having described the principle of operation of my invention in what I consider to represent a preferred embodiment thereof, I desire to have it understood that the specific details shown are merely illustrative andthat the invention may be carried out in other ways.

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

1. In an electric switch, a supporting structure having spaced terminals, a switching element pivoted on said structure so as to be swingable to and from closed position between said terminals, a hinge bolt secured to said supporting structure, a hinge nut rotatably arranged on said bolt supporting said switching element and movable therewith, a compression member arranged in an operative relation to said nut so as to be compressed by said nut as said switching element is moved in a predetermined direction.

2. In an electric switch. a supporting structure having spaced terminals, a switching element pivoted on said structure so as to be swin able to and from closed position between said terminals, a hinge bolt secured to said supporting structure, a hinge nut cooperatively .threaded upon said bolt, means for supporting said switching element on said nut, a compression member arranged to be compressed by movement of said nut along said bolt as said switching element is moved in a predetermined direction so as to arrest the movement of said switching element in said direction.

having spaced terminals, a switching element pivoted on said structure so as to be swingable to and from closed position between said terminals, a hinge bolt secured to said supporting structure, a hinge nut cooperatively threaded on said hinge bolt, said switching element having means for removably attaching said switching element to said hinge nut whereby said hinge nut is turned by swinging. movement of. said switching element, a compression member arranged around one end of said bolt between a portion of said supporting structure and said hinge nut, said member adapted to be compressed by movement of said switching element in a predeteroperatively engage said plane nut surface whereby said nut is turned on said hinge bolt by swinging movement or said switching element, a compression member arranged around one end of said bolt. and adapted to be'compressed by said nut as said switching element is moved in a predetermined direction so as to arrest the movement thereof in said direction.

5. In an electric switch, a supporting structure having spaced terminals, 9. switching element pivoted on said structure so as to be swingable mined direction to buff the movement thereof in said direction.

4. An electric switch, a supporting structure having spaced terminals, a switching element pivoted on said structure so as to be swingable to and from closed position between said terminals, a hinge bolt secured to said supporting structure, a hinge nut cooperatively threaded on said hinge bolt, said nut having a plane surface,

to and' from closed position between said terminals, a, hinge bolt secured to said supporting structure, a hinge nut cooperatively threaded upon said hinge bolt, means for attaching said switching element to said hinge nut whereby said hinge nut will be caused to turn on said bolt by

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