US2324888A - Electric switch - Google Patents

Description

July 20, 1943. R. w. STROBEL 2,324,838

ELECTRIC SWITCH Filed May 1, 1940 2 Sheets-Sheet l in]! wi 4W Invehtorz Rudolph W. Strobe I,

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July 20, 1943. R. w. STROBEL 2,324,883

ELECTRIC SWITCH Filed May 1, 1940 2 Sheets-Sheet 2 1 Rudolph 133mg], .1 g 6- Patented July 20, 1943 2,324,888 ELECTRIC swrron Rudolph W. Strobe], Stephentown, N. Y., assignor to General Electric Company, a corporation oi New York Application May 1, 1940, Serial No. 332,718

16 Claims.

The present invention relates to electric switches, with reference more particularly to improvements in construction switches designed primarily for outdoor installation.

Among the objects oi the invention are the provision of an improved form of fused disconnect switch of the open drop-out type, an improved contact construction and arrangement for electric switches, and improved housing and shielding means for protecting outdoor switch contacts from weather and other adverse conditlons.

Other objects and details of that which I consider to be novel and my present invention, will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings, wherein are illustrated two exemplary drop-out, open type, fuse cutouts embodying the invention.

In the drawings, Fig. 1 is a side elevation of one of th exemplary cutouts; Fig. 2 is an enlarged side elevation, partially in section, showing details oi. the upper terminal parts of the cutout of Fig. i; Fig. 3 is a sectional plan view along the line 3-3 of Fig. 2; Fig. 4 is an enlarged side elevation, partially in section, showing details of the lower terminal parts of the cutout of Fig. 1; Fig. 5 is a sectional plan view along the line 5-5 of Fig. 4, looking in the direction of the arrows;

Fig. 6 is a front elevation of the lower terminal parts of Fig. 4, with some of the parts shown in section; and Fig. 7 shows a side elevation, partially in section, of a modification of the cutout of Fig. 1.

The cutout illustarted in Figs. 1-6, includes a supporting insulator It) provided with a mount ing bracket partially shown at H. Terminal pieces I2 and I3 are cemented or otherwise rigidly secured respectively on the upper and lower ends of the insulator. These terminal pieces are in the form of relatively heavy bronze castings, but may be made of other suitable form and material which will provide the desired strength and rigidity. Each terminal piece has an integral eyeleted projection M to which a line conductor may be connected.

Upper terminal piece l2 has a forwardly projecting arm l5 which is of T-shaped cross-section, and on the outer end of which arm is a hood l6. In the exemplary cutout illustrated, hood I6 is an integral part of the terminal piece casting, but it may comprise a separate part attached to the terminal piece. The hood has an open front and bottom and is formed, adjacent the Iront, with a groove or seat I! for a purpose 55 to be described. This seat extends approximately in a vertical plane, and portions of the side and top walls of the hood extend forwardly from the seat and flare outwardly as shown in Figs. 2 and 3, to serve as guides. The forwardly extending top wall portion also overhangs and serves as a protection for the front of the hood. A generally U-shaped latching clip and two contact fingers 2| are attached to the rear inner wall of the hood. The resilient arms of clip 28 extend toward the front of the hood and are provided adjacent their ends with detent portions 22 and flaring guide portions 23. The forwardly extending contact fingers H are backed on their upper sides by spring strips 24 and are arranged to press generally downwardly and outwardly on a fuse holder contact as described hereinafter.

Lower terminal piece iii also has a mounting portion of T-shaped cross-section, indicated at 25, and a forwardly extending portion formed to provide a hood 26 which is closed on the top, rear, and sides. The major portion oi the bottom of this hood is closed by a removable plate 21 held in place by a screw 28. A cross-piece 29 bridges the bottom of the hood just forwardly of plate 2'! and inwardly of the front of the hood. Two hook-like supports 30 extend forwardly from the cross-piece and provide trunnion seats 3| in spaced apart horizontal alinement. Hooks 30 are arranged so as to leave spaces 32 between the outwardly facing surfaces of the hooks and the adjacent opposed side wall portions of the hood, which wall portions are formed to provide disk-like bearing or guiding surface extending substantially in planes normal to the intended pivotal axis of the switch element later described. Within hood 26 and attached to the rear wall thereof is a generally U-shaped contact clip 33, the outer ends of which are bent inwardly and rearwardly to forma V shaped contact seat 34, as shown in Fig. 5.

The lower terminal piece l3 serves as a support for a pivoted switch element or blade which in the illustrated embodiment includes a fuse holder 35 and a hinge member 36. The fuse holder comprises an insulating expulsion tube 31 which is open at its lower end and closed at its upper end by a removable cap 38. One end of hinge member 36 is pivotally attached, by a screw 40 or other suitable means, to a collar M rigidly secured adjacent the lower end of fuse tube 31, Intermediate the ends of the hinge member are trunnions 42 engageable with trunnion seats 3| for pivotally supporting the switch ment of Fig. 7, which are particularly advantageous for employment where a switch or cutout of exceptional ruggedness is desired. In open cut outs of the general type illustrated, it has been the common practice to construct the upper and lower switch element supports of a material of high electric conductivity, such as copper or bronze, so that at least part of such supports may be included in the electric circuit. However, with the nonferrous metals commonly employed for the purpose, there are limits to the strength which can be secured without resort to impractical dimensions or costly designs. In the construction of Fig. '7, a considerable increase in ruggedness is secured, without resort to the expedients above referred to, by the employment of switch element supports in the form of malleable iron castings. Such castings surpass, in strength and rigidity, the nonferrous castings or similar supports heretofore employed, while at the same time being easier to manufacture and substantially less expensive. In order to avoid inclusion of the malleable iron, which has relatively poor electric conductivity, in the electric circuit, I provide an improved construction and arrangement of parts such that the malleable iron castings serve only as a supporting framework while paths of good conductivity are provided for the electric circuit.

By reference to Fig. 7, it will be seen that the malleable iron casting, which forms the upper support 60, is clamped at one end to the upper end of insulator ill by means of a U-shaped bolt 6i and cooperative clamping nuts 62. The outer end of part 50 has an integrally formed hood 6's which is similar to the hood iii of the first described embodiment. Secured to the inner rear wall of hood 53, by means of bolts 64, is a terminal assembly including the contact fingers 2i and a terminal plate 65, which fingers and plate are comprised of material having good electric conductivity, such as copper or bronze. Spring strips 24 for backing the contact fingers, also form part of the terminal assembly. Plate 65 is provided with a socket 66 and one or more clamping screws 61 for connection of line conductors or leads thereto. Entrance openings 68, one of which is shown in the drawings, are formed in the side walls of the hood for accommodation of the line conductors or leads. overhanging ledges 69 are formed above the entrance openings on the outer faces of the side walls of the hood so as to deflect water away from the openings.

The lower supporting part 10, which also comprises a malleable iron casting, is cemented. or otherwise secured at one end to the lower end of insulator ill and has an integrally formed hood portion ll which is similar to the hood portion 26 of terminal piece I3 of the first described embodlment. A contact 33, similar in form to that shown in Fig. 5, is secured to the inner rear wall of hood H by means of bolts 12, with one end of a terminal plate 13 clamped between the contact and the rear wall of the hood. Both contact 33 and plate 13 are comprised of metal having good electric conductivity, such as copper or bronze. The terminal plate is bent into generally L-shape and the free end of the late, disposed outside of hood H, is provided with a socket M and one or more clamping screws for connecting line conductors or leads thereto.

As a result of the structural improvements just described, there is secured a high degree of strength and rigidity which couldnot be secured with previous constructions in which the commonly employed materials of good conductivity were used for the switch element supports. The increased ruggedness is an important advantage since it renders the cutout capable of withstanding, without damage or impairment of operation, a greater amount oi rough handling and shocks incident to transportation, installation, and manual operation, as well as shocks due to powerful recoil of the expulsion tube. Also, the increased ruggedness is secured with no reduction in current carrying efllciency or convenience of making connections.

Both of the illustrated constructions are simple and economical to manufacture, and have all the advantages of an open-type switch or cutout with the additional advantage that both the upper and lower contact parts are housed so as to be effectively protected against rain, sleet, and snow under all operating conditions. The enclosing of the contact parts in the manner shown, also prevents insects from nesting under the hoods and hampers the circulation of dust-laden or corrosive atmosphere around the contact parts. Yet, neither the automatic nor the manual operation of the cutouts is in any way hindered.

The present invention is not limited in all its aspects to the particular structural details or form of the switching devices herein described and illustrated, and it is contemplated that the teachings set forth herein will suggest other modifications and applications to those skilled in the art. Hence, it is to be understood that it is intended to cover by the appended claims such other modifications and applications as do not depart from the true spirit and scope of the invention.

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

1. An electric switch of the open type, comprising spaced terminals, a protective hood for a contact portion of one of said terminals, the other of the terminals being outside of said hood, a switch element for removable connection between said terminals, sald element being pivotally supported exteriorly of said hood and having a contact portion for engagement with said contact portion of said one terminal, and closure means for said hood, which said means is supported on said switch element and is formed and arranged for cooperation with the hood to provide a relatively tight housing completely enclosing said contact portion of said one terminal and said contact portion of said switch element when the latter is in connected position.

2. In an electric switch, spaced terminals, a protective hood for a contact portion of one of said terminals, the other terminal being outside of said hood, a switch element pivotally supported exteriorly of said hood and swingable into a position connected between said other terminal and said contact portion of said one termin'alh and closure means for said hood including a member supported on said switch element and having a portion disposed in generally laterally extending relation to the switch element intermediate the ends of said element, which said portion of said member is arranged to form a closing' wall for said hood in closely surrounding relation to the switch element when the latter is in connected position. v

3. In an electric switch of the open type, a protective hood, a terminal having contact means in said hood, a switch element pivotally supported outside of and generally below said hood, the hood being open generally downwardly and to one side so as to permit swinging of a contact portion of said switch element into engagement with said contact means, and means suuportw on the switch element operative to close said hood when the switch element is in connected position, said last means including a closure element extending in. closely surroun relation to the switch element intermediate the ends of said element and having a portion 11 ed to close the bottom part of the hood.

4. In an electric switch, spaced te, a. protective hood for a contact portion of one of said terminals, the other terminal being outside of said hood. 2. switch element pivot supported for removable connection between mic other terminal and said contact portion of said one terminal, said hood having an open portion arranged to permit swinging of said switch element into connected position, and means supported on said switch element for closing said open portion of the hood when the switch element is in connected position, said means including a member disposed in generally laterally extending relation to the switch element intermediate the ends of said element and arranged to form a closing wall for the hood around the switch element, said member having an opeg through which the switch element extends and being movable relative to the switch element 5. In an electric switch of the ogen type, a

protective hood having an open side and bottom,

a terminal having contact means in said head a switch element plvotally supported generally below said hood and having a contact portion swingable into engagement with said contact means, and a closure device supported on said switch element and formed and arranged to close said open side and bottom of the hood when the switch element is in closed circuit position, said device having an opening through which the switch element extends and being movable relative to the switch element.

6. Inan electric switch of the open type, a protective hood open on the bottom and one side, a terminal having contact means in said hood, a switch element pivotally supported generally below said hood and having a contact portion swingable into engagement with said contact means, and closure means for said hood, supported on said switch element and including two angularly related closure elements arranged to close said side and bottom, respectively, of the hood when the switch element is in closed circult position.

7. In an electric switch, spaced terminals, a hood relatively permanently associated with and partially enclosing a. contact portion ofone of said terminals, the other of the terminals being outside of said hood, a switch element for removable connection between said terminals, said element being pivotally supported exterlorly of said hood and having a contact portion swlngable through an open side of the'hood into engagement with said contact portion of said one terminal, and means supported on said switch element for closing said hood when the switch element is in. connected position, said means including two angularly related closure elements. one of which closure elements is arranged to close said open side of the hood, the other of said closure elements being arranged to close a part of the hood which is open in a. direction generally toward the pivotal support of the switch element.

8. An electric switch comprising a housing structure, a terminal having contact means in aooaeee said structure, a second terminal outside of sold structure, a switch element for removable connection between said second terminal and sold contact means, said element having a contact portion movable generally laterally through an open side of said structure into engagement with said contact means, and a closure device supported on said switch element for closing said housing structure when the switch element is in connected position, said device being movable relative to the switch element and having two angularly related parts, one of which parts is arranged to close said open side of the housing structure, the other of said parts extending gen erally laterally relative to the switch element at a point intermediate the ends of said element and being arranged to close a portion of sold housing structure which opens in a direction generally along the longitudinal axis of the com nected position of the switch element.

9. in an electric switch, a protective hood hav= ing an open side and bottom, a terminal having contact means in said hood, a switch element plvotally supported generally below said hood and having a contact portion swingable into ongagement with said contact means, and a closure device supported on said switch element and including two angularly related members ar= ranged to close said open side and bottom, respectively, of the hood when said switch element is in closed circuit position, said device being supported for angular movement relative to the switch element about an axis generally normal to the plane of swinging movement of the switch element. 1

16. In an electric switch, a terminal, a housing structure relatively permanently associated with and partially enclosing a contact portion of said terminal, a second terminal located exteriorly of said housing structure in spaced relation to said first mentioned terminal, a pivoted switch elemerit for removable connection between said terminals, said element being swlngable relative to said housing structure and having a contact portion engegeable with said contact portion of said first terminal, and a closure device supported on said switch element for closing an open portion of said housing structure when the switch element is in connected position, said closure device and switch element being connected for movement relative to each other and the closure device having a handle for engagement by a switch operating tool.

ii. In an electric switch, spaced terminals, a protective hood for a contact portion of one of said terminals, a pivoted switch element swingable into a position connected between the other of said terminals and said contact portion of said one terminal, and guide means including a generally V-shaped part carried by said switch element and having its apex forwardly in the direction of circuit closing movement of the switch element, which said part is arranged to engage said hood in a manner to guide the switch element into connected position.

12. In an electric switch, the combination of i a protective hood having an opening in one side switch element, said part being arranged to engage said hood adjacent said opening so as to guide said terminal portion of the switch element into the hood.

13. In an electric switch, a relatively stationary structure including a housing and a pair of trunnion supports disposed between and in alinement with two spaced opposed wall portions of said housing, contact means in said housing, a switch element for cooperation with said contact means and having a pair of trunnions removably engaged with trunnion seats provided by said supports for pivotally supporting the switch element, and disk-like enlargements on the outer ends respectively of said trunnions and rotatable in spaces provided between said supports and the respectively adjacent ones of said wall portions of the housing, said enlargements having guide surfaces arranged to cooperate with said wall portions of the housing so as to guide the movement of said switch element.

14. In an electric switch, a relatively stationary structure including trunnion supports, a switch element having trunnions removably engaged with said supports for pivotally supporting the switch element, said element also having disk-like guide members rigidly related to said trunnions and spaced apart substantial distances axially relative to the axis of the trunnions, said members extending in parallel relationship substantially normal to the pivotal axis of the switch element and the outer peripheries of said members being at substantially greater radial distances from said axis than the radial distance from the axis to the peripheries of said trunnions, and separate guide means forming part of said stationary structure and arranged for cooperation with said members to guide the movement of said switch element.

15. In an electric switch, relatively stationary trunnion supporting means, a switch element having a hinge part including trunnions removably engageable with said supporting means for pivotally supporting the switch element, said hinge part also including a disk-like guide member rigidly related to said trunnions and extending substantially normal to the pivotal axis of the trunnions, the outer periphery of said member being at a substantially greater radial distance from said axis than the radial distance from the axis to the periphery of the trunnions, and separate relatively stationary guide means adjacent said supporting means and arranged for cooperation with said guide member to limit angular movement of said member and trunnions to substantially pure rotation about the pivotal axis of the trunnions.

16. In an electric switch, stationary supporting means, a switch element having trunnions removably engaged with said supporting means for pivotally supporting the switch element, guide means on the switch element adjacent and rigidly related to said trunnions, said guide means having at least two bearing surfaces which face in opposite directions and extend substantially in planes normal to the axis of said trunnions, said surfaces being spaced apart a substantial distance axially relative to the axis of the trunnions and portions of said surfaces being at substantial distances radially outward from said axis, and separate means providing spaced apart oppositely facing stationary bearing surfaces respectively opposed to said first mentioned surfaces in a manner to confine said trunnions against axial movement and to limit angular movement of the trunnions to substantially pure rotation about their axis.

RUDOLPH W. STROBEL.

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