US2163069A - High voltage nonarcing selector switch - Google Patents

Description

L. C. STRINGER HIGH VOLTAGE NONARCING SELECTOR SWITCH June 20, 1939.

Filed April 29, 1937 I j V v7////// 7/////////6///////////// Inventor A itorneys Patented June 20, 1939 UNITED STATES PATENT OFFICE Louis C. Stringer, Chicago, 111., assignor to Electronics Supply Corp., a corporation of Delaware Application April 29, 1937, Serial No. 139,822

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The invention herein shown, described and claimed, pertains to a structurally novel and improved rotary, manually controlled, high voltage selector switch expressly designed to abolish with 5 certainty the ever objectionable dragging of an arc not now satisfactorily overcome by present prevailing selector switches.

Needless to say, I am generally conversant with the prior state of the art to which the in- 10 vention-relates, as well as the industrial conditions prevailing. As a matter of fact, it is common knowledge among those skilled in the line of endeavor with which we are here concerned that where electrical energy is stepped up to a l5 potential or frequency susceptible of developing an arc, as in step-up transformation where an appreciable intensitive current is involved, the user of the ordinary selector switch is confronted with the problem known as dragging an arc,

20 with the attendant result of burning and damaging not only the selector arm, but the contact point as well.

Although efforts have been made by my predecessors striving to cope with this undesirable 25 state of affairs, in so far as I have been able to ascertain structures provided therefor are incapable of satisfactorily accomplishing results in keeping with the demands of the trade. It follows, therefore, that my objective, in the main, is

80 to generally improve upon prior patented and marketed switch constructions through the adoption and use of a switch or equivalent structure which may be successfully used ofi a connection of the high side of a transformer without the 85 attendant disadvantages and damages present in available constructions.

In reducing to practice the principles of the broad inventive concept with which we are herein concerned, I have evolved and produced a sim- 40 ple, fool-proof, and aptly fitted structural assemblage calculated to correct existing conditions, this being attained through the instrumentality of means incorporated in the switch whereby before the selector arm can be conveniently released and set into motion, the source of current may be temporarily out off rendering the switch dead until the selector arm has been completely adjusted from a given contact to a predetermined selected contact.

Features and advantages supplementary to those so far exposed will become more readily apparent from the following detailing description and accompanying drawing.

55 In the drawing, wherein corresponding numerals are employed to designate like parts throughout the views:

Figure 1 is a view, partly in section, and partly in elevation, illustrating the preferred embodiment of the invention possessing the merits hereinafter defined and claimed.

Figure 2 is a horizontal section on the plane of the line 2-2 of Figure 1.

Figure 3 is a horizontal section of a fragmentary character on the line 33 of Figure 1, looking in the direction of the arrows.

Figure 4 is a fragmentary elevational view of the make and break device in the source of electrical supply.

Reference being had now to the drawing by distinguishing reference numerals, it will be observed that the numerals 5 and 6 designate spaced parallel plates of appropriate insulation material. These are joined in parallelism by connecting bolts 1 surrounded by spacing sleeves 2o 8 interposed between the parts as portrayed to advantage in Figure 1. On the disc 5, preferably the margin thereof, and at circumferentially spaced equi-distant points, are the contact buttons 9 with the power take-01f binding posts I0.

The numeral H designates a rotary tubular actuating handle mounted for rotation in the upper plate or disc 5 and held partially in place by the retention ring l2. On the upper end of the handle is an appropriate control knob I3 suitably knurled. On the interior and adjacent the upper end is a fitting or insert 14 constituting an abutment or shoulder. On that portion of the handle .forming the lower end and located between the discs 5 and 6 is a collar fixedly attached to the handle. This collar I5 carries the integral lateral selector finger or arm I5. An eccentric socket is formed in the collar parallel to the handle to accommodate a spring-pressed detent l1 accessible by way of the plug nut l8. The pointed end of the detent is cooperable with keeper notches or seats l9 formed in the under side of the companion keeper ring 20. Electrically connected with the lateral extension on the margin of the ring 20 is a binding post 2i delivering the transformed or controlled current to the selector switch. In actual practice the keeper seats IQ for the latch or detent I! are precisely milled to be in coincidental radial alignment with the peripheral stationary contact buttons or elements 9. Consequently, each keeper notch registers with its associated contact, making it possible to mechanically lock the contact 56 finger or arm l6 against accidental displacement when once it is adjusted to place.

I next call attention 'to a reciprocatory or slidably mounted rod 22.slidably mounted in the tubular handle H and operable through the collar M. It is provided on its upper end with a concentric secondary knob 23 coordinated with the main'control knobylii. A coil spring 24 is interposedbetween the collar M and the knob 23 to maintain the latter projected to the position illustrated in the drawing. The rod or member 22 is the control means for the circuit make and break device denoted by the numeral 25.

movable contact 21, with which the current supply wires 28 and 29 connect. The wires 28" and 29 are maintained normally in electrical circuit by the contacts 26 and 21, these being maintained in circuit making condition by the spring 24.

In practice it is obvious that the discs 5 and 6, the handle II, the knob l3, the rod 22, and knob 23, the collar l4 are of insulation material. The keeper ring 20, the collar. I5, the finger I6, and contacts, are of course of electricity conducting material.

The operation of the'switch is as follows: Upon placing the hand of the operator on the previously described wheel or knob l3, a movement of the contact finger I 6 cannot take place until sufficient pressure from the palm of the hand is exerted to acquire the desired oscillatory or rotary motion. The pressure is simultaneously brought to bear on the auxiliary knob 23, driving the rod 22 downwardly, disengaging the contact 21, and opening the power circuit at the breaking point 25. Thus, by cutting off the supply of current momentarily, the whole selector switch is rendered dead for corresponding periods, allowing the arm IE to be shifted from one contact to another at the discretion of the user. therefore, that during this shift, the aforementioned objectionable dragging of an arc is positively eliminated.

It is thought that the description taken in connection with the drawing will enable a clear understanding of the invention to be had.

.This comprises relatively stationary contact 26 and It follows,

Therefore, a more lengthy description is thought unnecessary.

While the preferred embodiment of the invention has been shown and described, it is to be understood that minor changes coming within the field of invention claimed may be resorted to if desired. 3'

A selector switch of thejclass described comprising a pair of spaced parallel plates of insulation material, a plurality-of circumferentially spaced contact buttons'mounted on the under side of the top plate, said contact buttons including individual binding poststo accommodate power take-off wires, a metallic ring secured to the central portion of the under side of said top plate,

said top plate having an opening in alignment with the opening of said ring, said ring being provided on its under side with radial keeper notches, a tubular handle mounted for rotation in the apertured portion of said top plate and extending through and beyondsaid ringand terminatingshort of .the bottom plate, a collar secured to the lower end of said handle, said tact member cooperable with said first named member, a. second conductor wire connected with said movable contact member, a rod slidably mounted in said bottom plate, said movable contact member being mounted on'said rod, said rod extending upwardly through the tubular handle,

said handleand said rod being provided with closely allied operating knobs, a stop shoulder mounted in said handle, a coiled spring on said rod engageable .with said stop shoulder and the adjacent knob whereby to maintain the movable contact member in normal electrical connection with the stationary member.

LOUIS C. STRINGER.

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