US2709725A - Electric switch - Google Patents

Description

y 1, 1955 c. E. BIEBER ETAL 2,709,725

ELECTRIC SWITCH Filed March 16, 1954 2 Sheets-Sheet l REVERSIBLE INVENTORS. Charles E Busber BY Robert 5'. Carr RNEY y 1, 1955 c. E. BIEBER ET AL 2,709,725

ELECTRIC SWITCH Filed March 16, 1954 2 Sheets-Sheet 2 jag/.

INVENTORS. (it Q7166 E. Bweber 3y Raberi 5. (arr IZTTORNLY United States Patent ELECTRIC SWITCH Charles E. Richer, Elizabeth, and Robert S. Carr, Summit,

N. J., assi nors to Airtron, Ind, Linden, N. J., a corporation of New Jersey Application March 16, 1954, Serial No. 416,454

8 Claims. (1C1. 200-4) This invention relates to electric switches and, more particularly, to switches designed for handling relatively high voltages of such high order as to require efficient insulation about the switches contact points to prevent energy leakage.

it has been found that electrical energy of such high voltages may usually be most efiiciently conducted through so-called coaxial cables; and, for illustrative purposes, the present invention is described herein with reference to a switch which is suitable for use with CO- axial cables.

An important object of the invention is the provision of an electric switch having an insulation effectiveness at the switchs contact points which is favorably comparable to the insulation effectiveness in related coaxial cables with which the switch is to be used.

Another important object of the invention is the provision of an electric switch wherein the insulation at the contact points is in intertelescoping relationship to lengthen the leakage path and thereby enhance the efiicicncy of such insulation.

Another important object is the provision of an electric switch having a switching element which undergoes such movement between switching positions as to permit the mentioned intertelescoping arrangement of insulation.

The foregoing and other objects are accomplished by means according to this invention, of which an illustrative embodiment is shown in the accompanying drawings.

in the drawings:

Figure l is an approximately central longitudinal sectional view of a switch according to a preferred embodiment of this invention with its switching element in one of plural switching positions.

Fig. 2 is a somewhat similar but fragmentary view of said switch with its switching element in an open or non-switching position.

Fig. 3 is an end view of said switch, on a reduced scale, as seen from the left side of Figs. 1 and 2.

Figs. 4 and 5 are transverse sectional views of the switch, substantially on the line XX of Fig. 1, each showing the switching element in a different switching position.

The illustrated switch comprises a U-shap d switching element 10, fixedly mounted on an angularly and translationally movable carrier 12 which is connected, through transmission means generally indicated at 14, to a reversible electric motor 16; all said parts being suitably fixed within a preferably dust-tight casing 18.

The carrier 12 is formed with a single trunnion 20 at its front end, borne for axial sliding and for rotation within a bore 22 in an extension 24 of an end plate 26 of the casing 18; said bore being suitably vented in a manner, not shown, to prevent air-lock therewithin. Coaxially with the extension 24, the carrier is formed with a hub 23, at its back end, having a rearwardly opening bore 36 within which rotatably and axially ice slidably extends a transmission shaft 32, fixed by a set screw 34 upon spindle 36 of motor 16.

The transmission shaft 32, at its front end, is formed with two spiral, reverse, crisscrossing threads 38 and 40 within either of which, according to operating conditions, may extend a drive finger 42 of a driving insert 44 suitably fixed into the wall of hub 28. The carrier l2 is yieldably urged leftwardly, as viewed in Figs. 1 and 2, by a coil spring 46 which is compressed between the back end of the carriers hub 28 and front end plate 48 of the motor 16.

The U-shaped switching element 10 is in the nature of a. jumper preferably having similar legs and contacts. T he jumper is a bent, short length of cable having an inner, high potential, conductor 50 surrounded by a dielectric sleeve 52 which, in turn, is encased by a braided, conducting-metal sheath 54 which serves as an outer conductor. Each leg of the switching element further includes a shouldered ferrule 5-5 into which the ends of the U-shaped cable length are firmly fixed as, for example, by being soldered or welded thereinto; the ferrules of the two legs extending with a. tight, fixed fit through separate holes 58 in a plate portion 60 of the carrier 12, which holes, as may best be understood from Figs. 4 and 5,are at different radii of the carrier, but equidistant from the trunnion 29.

The dielectric sleeve 52 terminates at or just inwardly of the plane of the outer end of the ferrule 56 and is formed with a cylindrical, axial end bore or recess 62 at the bottom of which the inner conductor 50 terminates in an exposed contact point or button 64. Such ends of the switching element are referred to hereinafter, for convenience, as switch terminals. As hereinafter explained, the switching element 10 is intended to switch electrical connections between two sets of cables. For this purpose, in the illustrated embodiment, three similar cable ends, hereinafter referred to, for convenience, as cable terminals, are connected into similar apertures 66, 68 and (Fig. 3); said apertures being so disposed that said switch terminals, in one angular position of the carrier 12, are in axial alignment with apertures 66 and 68 and, in another angular position of said carrier, are in axial alignment with apertures 70 and 68. The cable connected into aperture 68 may be common to two separate electric circuits while the cables connected into apertures 66 and 70 may each be independent parts of said two circuits.

As the cable terminals and their mountings are all, preferably, alike, the illustration of one of them in Figs. 1 and 2 should serve to illustrate all three. Such cable terminals each comprise an end of a cable 72, of the same general character as the cable length of which the jumper it; is formed, wherein the end of its dielectric sleeve 52a is of reduced cylindrical form as at 74 and is complemental to and adapted to telescope snugly within recess 62 of a related switch terminal. The cable terminals inner conductor 500 extends to and terminates, at the end of the reduced end portion 74 of dielectric sleeve 52a, in a contact point or button 64a, which, when the switch is closed, as in Fig. 1, seats firmly against contact point 64 to maintain electrical connection between inner conductors 5t} and 58a. The cable terminal is coupled to plate 26 in fixed position at a related aperture 66, 68 or 7t? by a coupling nut 76 threaded onto a circular flange 78 or' plate 26, which flange defines said aperture. A radial flange 89 of the coupling nut bears forcibly against a metal collar 32 which is fixed upon the cable terminal in a suitable manner, as by welding or soldering, to sheath 54a of the cable terminal, and said collar is thus held firmly against the end of flange 78. The end of the latter is turned in as at 84 to form an abutment to limit positively the extent to which the ferrule 56 and a related 3 switch terminal may pass within the flange 78 when the switch is closed.

Similar stops 86, 83 are suitably fixed in proper positions upon the back of end plate 26 of the casing, as shown in Figs. 4 and 5, to limit the carrier 12 to back and forth angular movement of about 60 between two switching positions shown separately in said figures. Said stops, of course, are of sufficient dimension axially of the device, as may be seen from the showing of stop 88 in Figs. 1 and 2, that they may engage side edges of the plate portion 60 of the carrier when the latter is in its extreme inward position indicated in Fig, 2.

The device also may advantageously include a pair of microswitches 90, 92, suitably secured together with their operating buttons 9%11 and 92a oppositely disposed as in Figs. 4 and 5 and rigidly supported upon a bracket 94- suitably fixed to the back of end plate 25 of the casing. Aswitch actuating plate or finger 96 is suitably fixed to the hubZS of the carrier at such axial position the inner end of said hub that said finger will coast properly either with microswitch button 920 as in'Figs. l and 5 or with microswitch button 9% as in Fig. 4.

The mentioned microswitches may be in circuits which control the operation of motor 16 and may function either merely to stop said motor or to automatically reverse said motor after completion of one hereinafter described switching movement of switching element 19. Such circuits and motor controls, however, are not an essential part of this invention and, for this reason because of the many circuit arrangements which they may involve, said circuits and controls are not described in detail or illustrated herein.

In order to better understand the described structure and its operation, it may be assumed that, at the start of a cycle of operation, the switching element 1% is in its Fig. 4 position'with its switching terminals in intimate switching engagement with two related cable terminals in the manner shown in Fig. 1. By remote control, the motor 16 is caused to operate to turn transmission shaft 32 ccunterclockwisely as viewed in Fig. 4. As the car rier 12 cannot turn because of the switching terminals being partly withincable apertures 65 and 63, such turning of shaft 32 causes drive finger 42 to ride rearwardly within thread 4b of shaft 32 until the switching terminals have been completely withdrawn from the apertures 66 and 68 as in Fig. 2.

During the latter part of such withdrawal of the switching terminals, the latter are substantially clear of the end plate 26 so that the effect of the described rotation of shaft 32 at that time, together with the effect of the reacion of the compression spring as, is to urge the driving finger 42 countcrclockwisely together with the entire carrier 12 and the switching element ltl until said carrier abuts and is stopped by stop 86 wherein the switching terminals are 'n alignment with but still clear of cable apertures 68, 70. The drive finger 42 then traverses a semicircular slot or groove 93, indicated in broken lines in Figs. 1 and 2, which connects the back ends of the threads 38 and 49.

The drive finger 42 passes from groove 98 into thread 38 and, as this thread spirals oppositely to thread 4%, the continued turning of shaft 32 in the same direction as theretofore, together with the force of spring 46, causes the finger 42 to move forwardly and, of course, the entire carrier 12 and the switching element 10 also move forwardly, thereby moving the switching terminals into cable apertures 68 and 70 to close the switch in its Fig. 5 position with the contact points 64, 64a of the opposed switching and cable terminals in contact with each other. This contact is firmly maintained by the force of spring 46 even after stopping of the motor as hereinafter described. The sheaths 54, 54a, meanwhile, are connected for conduction through ferrule 56, portion 3a of flange '73, and collar 82.

As the carrier 12 nears the end of its just-described forward movement, switch actuating finger 96, then in axial alignment with microswitch button 92a, presses that button to operate microswitch 92 and thereby either stop the motor 16 to leave the switch closed or automatically reverse said motor to gain switch back to the Fig. 4 switching position. Which of these alternatives occurs, depends upon the manner in which the said microswitch is associated with the controls of motor 16. It should be clear, of course, that operation from the Fig. 5 to the Fig. 4 switching position would involve reverse operation of motor 16 and coaction of drive finger 42 first with thread 33 and then with thread 43 to assure clockwise movement of the switching element 19.

It may be remarked that end bores 62 of the dielectric sleeve 52 of the switching element are suitably vented to avoid air lock therein, as, for example, by providing a somewhat loose fit of the reduced ends 74 of the cables dielectric sleeves within said bores or by providing a groove, either straight or spiraling about said reduced ends, from said bores to ambient atmosphere.

This invention may be utilized in an arrangement wherein the switching element comprises either only one switching terminal or more than two switching terminals as, in either of these circumstances, the same mode of operation, i. e., (l) pulling a switch terminal, (2) angularly moving said terminal and (3) pushing said terminal, may be desirable. It should be apparent that the present inventive concept may be employed in various other ways without departing from the invention as set forth in the following claims.

We claim:

1. A telescopingcontact electric switch comprising a translationally and angularly movable carrier having a switching terminal non-coaxially associated therewith, plural, spaced, fixed cable terminals in axial alignment with the path of angular movement of said switching terminal and in a common plane perpendicular to the carriers axis, a pair of stops limiting said carrier to angular movement between two positions, a rotary transmission shaft coaxial to said carrier and having oppositely directed spiral grooves, and a radial driving finger rigidly associated with said carrier and adapted to slide within said grooves; said finger being adapted, while angular movement of said carrier is prevented by telescoping interengagement of the switching terminal with one of said fixed terminals, to coact with a first one of said grooves to move said carrier translationally to shift the switching terminal out of contact with said one fixed terminal and to move said carrier and switching terminal angularly in one direction to bring the latter into axial alignment with another of said fixed terminals, said finger being further adapted, while angular movement of said carrier is limited in said one direction by one of said stops, to coact with another of said grooves which spirals oppositely to said first groove to move said carrier translationally, oppositely to its first-mentioned translational movement to shift the switching terminal into telescoping contact with said other fixed terminal.

2. An electric switch according to claim 1, further characterized in that said carrier has a second switching terminal, the two switching terminals being adapted to connect with different combinations of cable terminals in the two angular positions of the carrier.

3. An electric switch according to claim 1, further characterized in including spring means continuously urging said carrier toward said cable terminals.

4. An electric switch according to claim 1, further characterized in that said transmission shaft has a groove connection between the back ends of two such oppositely spiralling grooves.

5. An electric switch according to claim 1, further characterized in that the carrier has, at its back end, an axial, cylindrical, recess into which the transmission shaft slidably extends, the driving finger extending radially inwardly from a side wall of said recess.

6. An electric switch according to claim 1, further characterized in that said transmission shaft is reversibly rotatable to adapt the switch for operation in opposite angular directions.

7. An electric switch according to claim 6, further characterized in including a motor for operating said transmission shaft, a switch actuating finger extending radially from said carrier, and a pair of control switches adapted to control said motor and each having a switch operating member forwardly of said switch actuating finger and in axial alignment therewith in a different extreme angular position to which said finger may move; said members being adapted to be engaged and operated by said finger during forward movement of the carrier to stop said motor.

8. A telescoping-contact electric switch comprising plural, spaced, fixed, cable terminals arranged in a cornrnon plane, a switching terminal supported for movement to and from telescoping contact with said cable terminals in lines perpendicular to said plane and for movement in parallelism with said plane between said lines, and means for shifting said switching terminal from contact with one of said cable terminals to contactwith another of said cable terminals; said shifting means comprising a translationally and angularly movable carrier coacting with said switching terminal to cause the stated Cir movements thereof, and having a radially extending drive finger fixed thereto toward one side of said carriers axis of angular movement, means restraining said carrier against angular movement during translational movement and against translational movement during angular movement, and a rotary transmission shaft having reverse threads within which said drive linger extends; one of said threads coacting with said drive finger during restraint of such angular movement to move the carrier translationally to shift said switching terminal first from telescoping contact with one of said cable terminals and then, following termination of the last-mentioned restraint, into alignment with another of said cable terminals, and another, reversely extending one of said threads coacting with said drive finger during further restraint of such angular movement to move the carrier reversely translationally to shift said switching terminal into telescoping contact with said other cable terminal.

References Cited in the file of this patent UNlTED STATES PATENTS 1,399,107 Frankowski et al. Dec. 6, 1921 1,715,991 Chandler June 4, 1929 2,502,761 Stachowiak et al Apr. 4, 1950 2,516,606 Weaver et a1. -1 July 25, 1950

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