US427521A - Ocron s - Google Patents

Description

(No Model.) 0. S. PLATT 8v J. M. ORPORD.

ELECTRIC SWITCH. No. 427,521. Patented May 6, 1890.

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OCRON S. vPLATT AND .IO'IIN M. ORFORD, OF BRIDGEPORT, CONNECTICUT; SAID ORFORD ASSIGNOR TO SAID PLATT.

ELECTRIC SWITCH.

SPECIFICATION forming part Of Letters Patent N0. 427,521, dated May 6, 1890.

Application filed October Si 1889. Serial No. 326,313. (No model.)

To all whom, t may concern,.-

Be it known that we, OcRoN S. PLA'rr and JOHN M. ORFORD, citizens of the United States, residing at Bridgeport, in the county of Fairfield and 'Stat-e of Connecticut, have invented certain new and useful Improvements in Electric Switches; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to certain new and useful improvements in electric switches, and has for its object to provide a device of this description which shall be simple in construction and inexpensive to manufacture, in which the handle may be turned in either direction to operate the switch, and in which the making and breaking of contact, and particularly the latter, shall be effected with great quick-v ness. Furthermore, our invention relates to a novel device for insuring close and efticient contact with the terminals, which shall be constantly operative and not liable to deteriorate; and with these ends in view our invention consists in the construction and combination of elements hereinafter fully set forth,and then recited in the claims, and particularly in the arrangement of parts whereby the contact-bar is cam-actuated in one di reetion and spring-actuated in the other.

In order that those skilled in the art to which our invention appertains may fully understand how to make and use our improvement, we will describe thesame in detail, reference being had to the accompanying drawings, which form a part of this specification, and in which- Figure l is an elevation showing the switch closed, the inclosing-cap being sectioned and part of the base broken away; Fig. 2, a longitudinal vertical section showing the switch open; Fig. 3, a plan view, partly in section, showing the paris in their closed position; Fig. 4, a detail transverse vertical section showing the parts in their closed position; Fig. 5, a detail end elevation of the bar and terminals in their closed position; Fig. 6, a detail plan view of the contact-bar with contacts removed, the legs of the housing being shown in section; Fig. 7 a detail transverse section through the wedge, showing the connection between it and the operati11g-s1indle.

The drawings represent our invention as embodied in a double-pole switch; but it is obvious that it is equally applicable to an ordinary single-pole switch.

Like numerals refer to the same parts in all the figures of the drawings.

lis a base-block, which maybe of wood, porcelain, or other suitable material, and upon whose surface are secured the terminals 2, to which the circuit-wires are adapted to be attached in any usual or suitable manner. The opposed faces of these terminals are preferably inclined, as seen at the detail, Fig. 5, so that the space between them may be convergent from the top of the terminals to the surface of the block. The terminals are properly insulated from each other.

3 is a housing mounted on the block at about the center thereof, said housing being constructed, preferably, with four posts or legs, so as to leave it open both at its ends and sides. Vithin this housing, which forms a bearing in which it may slide vertically, is arranged the contact-bar 4t, having in its top a recess 5, V-shaped in cross-section, and substantially vertical as to its end walls.

(i is a spindle having a handle 7 at its upper end. Said spindle passes vertically through the top of the housing, and immediately below the top wall of said housing it carries a wedge-shaped cam S, conformed in cross-section to the shape of the recess in the contactbar.

The connection between the spindle and the cam will be readily understood by reference to the small detail, Fig. '7, which shows the cam as pierced vertically for the passage of the spindle and said spindle as having a transverse opening 9, tapered from either end to the center thereof, and a pin l0 passed lengthwise through the cam and the doublytapered opening. The purpose of this method of connection will presently appear. The

lower end of the spindle passes downward into a recessll in the base-block, and has a bearing in the bottom of the latter, and a spring 12 is coiled loosely about the spindle,

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and has end bearings respectively against the bottom of the recess and the lower surface of the contact-bar.

13 is a washer secured to the spindle.

14 are insulating-washers slightly larger in diameter than the central portion of the contact-bar, and secured upon the ends thereof inside the caps l5, also of insulating material. i

1G are ferrules, preferably of conducting material, surrounding the caps 15, and to these are secured, as by screws, a series of thin iiexible plates broadly U-shaped, as seen at the detail, Fig. 5. Heretofore such plates for contact purposes have been employed; but when made of pure copper, so as to be of high conductivity, they have been found of low resilience, and consequently have been liable to retain their bent shape and so fail to give the strong and perfect contact required. Conversely, when made of metal of high spring quality they are deficient in conductivity and furnish a section in the circuit having relatively high resistance.

` In order that the requisites of conductivity and resilience may both be present, we employ plates formed of different metals, and preferably arrange these contacts with an inner plate of German silver 17, designed to furnish the required spring quality, and an outer plate or plates 18 of pure copper for its high conductivity. Thus the contacts are of nearly or quite as high conducting power as if ofpure copper, and the inner plate or plates of spring metal give a resilience substantially such as would be derived from contacts made entirely of such metal. Any number or arrangement of such plates, provided they be of metals differing in resilience, we deem to be within the scope of our invention; but German silver is preferred for the inside plates, since its spring quality is but slightly affected by heat.

19 is a plate-spring secured to the side of the housingand bearing with its end against the extremity of the cam when the latter is inthe position shown at Figs. 1 and 3. In place of this spring, or as auxiliary thereto, we may provide shallow notches 20 on the top of the contact-bar, and in which the sharp edge of the cam may rest when the switch is closed. The object of the notch and spring, or either of them, is to hold the cam in its position transverse to the bar as against returning to the recess in the bar, either by jar or by means other than the turning of the spindle. Said notch and spring or either of them also serve to indicate to the person operating the switch when the contact is complete.

In the operation of our invention, when the switch is open the wedge-shaped cam rests in the V-shaped recess in the contact-bar, and the contact-plates are above the space between the terminals and out of contact with In closing the switch the spindle is turned by means of the handle, whereupon the cam drives the contact-bar downward and rides over the inner faces of the recess until its edge rests transversely on the top of the bar and in the notches, or with the spring bearing against` its end, or both, according to the construction of the switch. This downward movement of the bar is effected against the action of the spiral spring, and causes the plates on the ends of said bar to be forced into close contact with the terminals, which contact, the spring quality of the resilient plates helps to make and preserve. When the handle is turned with reasonable rapidity, the closing of the circuit is effected very quickly. In opening the circuit the spindle is turned by the handle until the ends of the cam strike the edges of the inclined recess in the bar, whereupon the upward pressure of the spring jumps the bar out of contact very quickly and turns the cam so that it seats in the recess. It is to prevent any delay in this operation that the wedge and spindle are connected in the manner shown at Fig. 7, which method of connection admits of a slight rotary movement being imparted to the cam, so that it may seat in the recess irrespective of the continuance of the turning movement of the handle beyond the point necessary to carry the points of the cam to the top of the inclined surfaces of the recess.

In this our invention we do not wish to be confined to the precise details of construction herein shown and described, since many minor changes not involving the exercise of invention may be made therein without departing from the spirit and aim of our invention, as set forth in the claims hereunto annexed.

IVe claim- 1. In an electric double-pole switch, the

combination, with the base and the two pairsv of insulated terminals, of a housing open at its ends and sides and mounted on the base between the terminals, a contact-bararranged within said housing and having side and end bearings against it, a Vshaped recess in the top surface of the bar, contact-plates mounted upon the ends of the bar and adapted to join the terminals, the rotary spindle, the spring, the operating handle, and the cam adapted to the recess and loosely secured to the spindle, substantially as set forth.

2. In a double-pole switch,the combination with the base and the two pairs of terminals, of the transversely-extended bar having upon its ends and insulated therefrom' the conducting-plates 17 1S, the housing secured over said bar and forming a bearing for said bar as against movement either sidewise or in the direction of its length, the rotative operating-spindle, and the cam adapted to move with the spindle and capable in addition of a limited movement independent of said spindle and about the latter as an axis, substantially as set forth.

3. In an electric switch, the combination, with the base and the terminals, of the contact-bar having contacts at its ends and hav- ICO IIO

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ing at its center transverse projections, the the broadly U-shaped plates 17 18, all arfour-legged housing set over said bar and ranged as described, and for the purpose set -adapted to limit its movement both lengthfortn. t

wise and sidewise, and means for imparting` In testimony whereof We atiix onrsignatures 5 to said bar its appropriate vertical movement in presence of two witnesses.

within the housing, substantially as set forth. Y o OCRON S. PLATT.

4C. In an electric switch, the combination, i JOHN M. ORFORD.

with the terminals, of the vertically-movable lVtnesses:

contact-bar having reduced extremities, the S. H. HUBBARD, Io Washers 14, the caps 15, the ferrules 1G, and M. C. HINCHCLIFFE.

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