US853370A - Spring-jack for telephone-switchboards. - Google Patents

Description

No. 853.370. PATENTED MAY 14, 1907. P. R. MOBBRTY & 5. B. GRAFT. SPRING JACK PoR TELEPHONE SWITGHBoA RDS.

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FRAN K R. MCBERTY, OF EVANSTON, ANI) EDWARD B. CRAFT, OF CHICAGO, ILLINOIS, ASSIGNOR(1 TO WESTERN ELECTRIC COMPANY, OF (IIICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SPRING-JACK FOR TELEPHONE-SWITCHBOARDS- Specification of Letters Patent.

Patented May 14, 1907.

Application filed December 10, 1904. Serial No. 236,278.

Be it known that we, FRANK R; MGBERTY and EDWARD B. CRAFT, citizens of the United States, residing at Evanston and Chicago, respectively, in the 'county of Cook and State of Illinois, have invented a certain new and useful Improvement in Spring-Jacks for Telephone-Switchboards, of which. the following is a full, clear, concise, and exact descri tion;

Our invention relates to a strip of springjacks for telephone switchboards, and its object is to provide an improved construction which will be compact, light, strong, simple and -cheap to manufacture, and which will insure reliable switching action and proper insulation of the conducting parts.

In accordance with our invention, the tongue or connecting strip which extends rearwardly from the test thimble or tube at the front of the jack, is bent a point between the front and rear supporting strips, .so that the rear portion of said tongue is disposed on edge or in a vertical plane, and is adapted to form a rigid backing piece lfor the line contact springs of the jack, which are also disposed on edge parallel to-said tongue and preferably on either side thereof. A pair of insulated contact springs may be mounted on edge between the rearportion of the tongue and one of the line springs, to be operated whenfsaid line spring is flexed by the insertion of the plug in the jack. The contact surfaces of the jack are thus disposed on edge to avoid accumulations of dust thereon, while providing for an extremely compact arrangement of the partspwith. great strength and rigidity, and efficient insulation.

The verticallydisposed portion of the tongue or connecting strip before referred to is united with the test tube or thimble by means of an arm or arms which may be bent to lie Iiat above or below the ends of the line springs and out of the pathl of the plug. Preferably the test tube and its connecting strip are formed integrally. from a sheetrnetal blank or punching, one end of said blank being rolled to form the tube,l and the rear portion of the connecting strip being united with the tube by two curved arms branching from the edges thereof, said arms being bent into parallel planes at right anglcs to the plane of the rear portion. The

connecting strip thus forms a rigid connection or support between the front and rear insulating supporting strips, which is particularly adapted to withstand the stresses in all directions to which the springjack will he subjected. Said connecting strip further forms a substantial backing piece for the contact springs, whereby they may he mailitained in their proper positions relative to each other and to the test tube. Such construction is furthermore especially adapted for "cut-'off jacks, where a switch contact is required in addition to the ordinary line springs.

In the accompanying drawing, Figure l is a plan view of a strip of springjacks enibodying our invention; Fig. 2 is a front elevation showing the openings adapted to receive the plugs, Fig. 3 shows an end view of the strip and a connecting plugin position to be inserted therein g Fig. 4 is an isometric view showing the several parts of a springjack ready for assembly; Fig. 5 is a detail view of the blank or punching from which` the test tube and its connecting strip are formed.

The same. parts are indicated by similar letters f reference throughout the several figures of the drawing.

As shown, the strip of springjacks comprises front and rear supporting strips m h of insulating material, and springj ackparts mounted therein. Each of the springjacks illustrated comprises .the usual line springs a, ZJ, a test tube or thiinble c and cut-off contacts e e. The test thiinble c is provided with a connecting strip or tongue extending to the rear supporting strip, said tongue comprising a flat rear portion d disposed in/a vertical plane in a groove in the rear supporting strip, and curved arms uniting said rear portion with the tube, said arms branching from the upper and lower edges of the rear portion and being turned over to lie in parallel planes at right angles to the plane of the rear portion, joining the rear edge of the test tube at the top and bottom thereof, respectively. The test tube with its connecting strip including the arms d d may be conveniently made from a Hat metal punching of the form shown in Fig. 5, one end of the punching being rolled up to form the tube, and the curved arms d d being lOO bent at the edge ol the straight, portion d into l parallel planos at right angles to the plane of said straight portion.

The real' portion of the strip d forms a rigid backing piece or traine for the contact springs and their insulating strips going to build up the spriugjaclr, These parts are assembled in parallel planes in a transverse slot or groove-in the `rear supporting strip, the line springs projecting 'forward with their free ends iininediatel5T behind the hole in the test t'liilnble, in position to engage the contacts ol an inserted. plug. The line springs are disposed as shown on opposite sides ol the backing strip d, the movement of the springs being liinited thereby. Insulating strips d2 d2 are provided on either side of the backing strip, said strips extending to the front end of the straight portion d', as shown.

The line spring a, which in this instance is the long line spring, is arranged to operate a pair of contact springs e c', which, together with their insulating strips, lie between said line spring and the insulating strip d2 which is at theJ saine side of the backing piece d'. The spring e carries an insulating spacer j which is adjusted to normali)T press the contact spring e against its lnate e, but when spring e is flexed, as by the insertion oi a connecting plug, such as the plug g shown in Fig. 3, the contact spring e is left free to rnove by its own tension out of engagement with its contact anvil e. These auxiliary contacts e e' may be used in accordance with the well known practice, to c-ontrol the circuit of a subscribers line signal.

The rear endsV of the springs and tongue d of the jacks oi the strip, together with the several insulating stri as interposed between such parts, are wedge edgewise into a transverse groove h in the rear insulating strip or block h, which serves as a rigid support for said springs. It will be noted that the bacl ing pieces or tongues d of the several jacks serve as a support for the insulating block h, each tongue also forming the frame or base upon which the parts oi' its own jack are assembled.@The springs and contacts of a jack being mounted on odge and parallel to one another, make a compact construction, and allow dust and. other 'foreign mattei' to 'liall between them instead ol" collecting on their surfaces and. interfering with the proper operation o'l" the device. Metal binding strips 'it' may be secured to the top and. bottoni of the strip it by screws, an insulating strip lc being interposed between the plate fi and the sup orting strip 7L over the grooves therein as s iown, where/b5T the parts ol: the jack are held against removal from said grooves.

We claiinzw 1. In a springjack, the combination with a pair of line springs and a test piece, said test piece comprising a tube, rearwardly extend,- ing tongue and arms uniting thein, said parts being stamped freni a single piece of metal, the line springs being located on opposite sides of said tongue and insulated therefrom, of a pair of contact springs lyinV next to each other between the tongue and one of said line springs, said springs being insulated from said tongue and line spring and arranged to be operated when the line spring is flexed, and an insulating block at the rear of the jack, in which said springs and tongue are mounted.

2. A sheet metal blank for a springjacl test thinible and connecting strip, consisting of a front portion adapted to be rolled to forni the tube, a rear portion adapted to serve as a connector, and two arnis joining said front and rear portions, said arms branching from said front portion at a diverging angle and recurving to join said rear portion.

In witness whereof, we hereunto subscribe our naines this 24th day of' October A. D., 1904.

. FRANK R. MUBERTY. EDWARD B. CRAFT.

Witnesses: A

FREDERICK l?. McIN'rosH, E. F. BEAUBIEN.

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