US585915A - johnston - Google Patents

Description

2 SheetsSheet 1.

(No Model.)

L. JOHNSTON. OPERATOR/S SWITGH FOR- TELEPHONE EXCHANGES. No. 585,915. Patented July 6, 1897.

/W. A o I TRANSMITTER a z u. u. o Q! Q? 3 3 J .J 0. n INDUCTION COlL firowrvz/ (No Model.) 1 2 S1186tS-Sh6t2.

L. JOHNSTON. OPERATORS SWITCH FOR TELEPHONE EXCHANGES. No. 585,915. Patented July 6, 1897v 3 i i a Rma OFF PROP TRANSMI E INDUCTION RECEIVER POWER GE-ER470 UNITED STATES PATENT OFFICE.

LOUIS JOHNSTON, OF LA CROSSE, WISCONSIN, ASSIGNOR OF THREE-FOURTHS TO IVILLIAM IV. CARGILTJ, FRANK P. HIXON, AND GEORGE II. GORDON, OF SAME PLACE.

OPERATORS SWITCH FOR TELEPHONE-EXCHANGES.

SPECIFICATION forming part of Letters Patent No. 585,915, dated July 6, 1897.

Application filed March 13, 1897. Serial No. 627,307. (No model.)

To aZZ whom it may cancern: receive a number of the devices which, being Be it known that I, LOUIS JOHNSTON, a citiduplicates of each other, the invention will zen of the United States of America, residing be readily understood, so as to be operatively at La Crosse, in the county of La Crosse, in the applied by the description of a single appa- State of \Visconsin,have invented certain new ratus and its associated mechanism and cirand useful Improvements in Electric-Telecuits. phone Circuit Changing Attachments for Referring to the drawings, A designates a Central Stations, of which the following is a box or casing made of hard rubber or other specification. suitable non-conductin g material and consist- IO The invention relates, primarily, to the ing of top and bottom plates12, connected and cam mechanism by which the circuit connecsupported by side pieces or plates 3 4;, the tion and disconnection of a telephone with casing being of such size and dimensions as to and from diiferent lines may be effected. adapt it to take and support any requisite The object of the invention is to change number of circuit changing mechanisms. I 5 the respective telephonic circuits through the The casingis preferably made with open ends. medium of a single circuit changing cam In the top or cover 1 of the casing are formed which controls all of the contacts which may the desired number of transversely-arranged be interposed in said circuits. slots 5, constituting guide-slots in which the The 1nvent1on Wlll be first described, and arm or shank of the cam-operator lever 20 then specifically pointed out in the claims. moves.

In the devices now used in the art for the B designates a circuit-changing cam made purposes to which the invention is adapted of suitable non-conducting material and of a material difficulty or objection to be oversuch length and breadth as to operatively come is that the material used in their 0011- contact or press upon the contact-springs of 2 5 struction is attended with so much friction the respective circuits to be made and broken that after the cams havebeenin use forashort through the instrumentality of the deprestime they become worn out and the intended sions and elevations formed in and on its uncontacts are imperfectly made and cutder face. On the under surface of this cirouts thus caused. It is one of the objects cuit-changing cam are formed a plurality of 30 of the present invention to overcome this decam ribs or lugs 13 14: 15 16 17 18 19 and of ficiency, and this is in a large measure accomcourse havingintermediate corresponding deplished by the improved constructions of my pressions, substantially as seen in Fig. 2 of circuit-changing cam. the drawings, the purpose being that the cam The invention is fully and clearly illusribs or lugs shall serve as contact means to 3 5 trated in the accompanying drawings, whereeffect the contact of the circuit-contact springs 8 5 inand that when the circuit-changing cam is Figure 1 is a perspective view of my imshifted to make and break other circuits the proved circuit-changing cam mechanism desprings shall have room to move upward and tached from the circuit connections. Fig. 2 out of contact into the recesses or depressions 0 is an inverted plan view of the circuit-changand break the circuits, as hereinafter will be 0 ing cam. Fig. 3 is a diagrammatic View of more fully specified. The circuit-changing the invention interposed in a circuit using a cam B is supported on rods 8 8, which slide generator having two lines or complete me in suitable bearings 71 formed in the sides of tallic circuit. Fig. 4 is a diagrammatic view the casing, so that the circuit-changing cam 45 of the invention as applied to a grounded cirmay be shifted or reciprocated across the cas- 5 cuit. ing and into and out of contact with the de- It will be premised that in the drawings in sired contact-springs. Fig. 1 but a single circuit-changing cam with On the upper face of the circuit-changing its connections is shown, but the casing or cam is formed orsecured a rack-gear 9 of such 0 supporting-box is shown as being adapted to length as to move it the required distance :00

endwisc in either direction. In the casing is secured a suitable hanger 10, in which is fulerumed a lever 11, the bar or handle of which projects through a guide-slot in the cover of the casing and may be provided with a handpiece 11 for the grasp.

On the lower end of the switch-lever is formed or secured a segmental gear 12,which engages with the rack-gear 0 011 the circuitehanging cam to move it into and out of contact with the contact-springs of the circuits to be made and broken. Each lever passes through or alongside of a curved lockingplate 1), provided with suitable recesses M1 engaged by a spring-tongue i, carried by the lever, whereby the lever and cam will be held in each one of the three positions to which they may be moved to make and break the respective circuits.

It will be perceived that by shifting the lever the circuit-(hanging cam is moved transversely across the casing and into and out of contactwith the springs, making and breaking the required circuits.

In the bottom of the casing are secured a number of contact springs or pieces a, Z), c, (I, c, and f, having one arm overlying the floor of the casing and having the other arm depending and projecting through the floor,substantially as shown, and connected, respectively, to a circuit-wire forming one of the circuits. Inasimilarmannercontact-springs (11, Z), c", d, c, andf are provided,which overlie the first-mentioned series a to f, inclusive, and having one arm extended through the floor of the casing and the circuit-wire of the other limb or line of the respective circuits connected thereto. The contact-arms of the upper series of contact-springs are preferably curved upward, as shown, so that the camlugs on the circuit-changing cam will bear on the arch of the curves and press the free ends of the springs,whieh normallystand free from the lower contact springs or pieces, down into contact therewith to complete or make the desired circuits.

It will readily be perceived that any form may be given the upper series of springs which will adapt them to be pressed down by the cam-lugs 011 the circuit-changing cam.

The respective pairs of contacts are arranged in two parallel longitudinally-alined series, and the under surface of the cam has its projections and depressions in two series at opposite sides of a central longitudinal line, so that the cam will overlie and operate all of the upper contacts of a single mechanism, as set forth in the description of the respective circuits.

In Fig. 3 of the drawings the invention is shown in diagrammatic illustration as in operative association with a dynamo-generator system of circuits, and reference being thereto had it will be seen that when the circuitehanging cam is in primary or normal position, being that as shown in Fig. 1 of the drawings, the cam-lugs 13 16 on the circuitchanger cam are in engagement with contacts a a and c c, which are pressed in contact, thus closing and completing the plugand cord circuits used when persons on these line connections are conversing, through wire 11 from (L to c and from (1. through wire 11", through plugs by wire 10 to contact 0.

To make the circuit required for the operatois talking-circuit, the circuit-changing cam is shifted a step to the left, so as to bring camlugs 13,15, 10', and 19 on the springs to close contacts a a, Z) Z), c c, and ff, a circuit be ing thus made through a d '11" 11* to 1: 0, wire 11- to Z) b, from Z) by wire it" to transmitter T, thence by wire 11 to contacts/7", and by wire 11) to c c.

\Vhen the operator shifts the circuit-changing cam to make the first ringing-circuit, it is moved another step to the left to bring cam-lug 16 to close (1 1;, lug 18 to close 6 e, and lug 17 to close (Z (Z'. A circuit is then established from the generator Gr by wire 11-", through c 6, wires 21' 11- to c, the other side of the circuit being from the generator G by wire 10, through 17 (Z, wire 11' to wire 11: and then by wire 11 to 0.

hen it is required to move the circuitehanging cam to establish the second ringing-circuit, it is moved a third step to the left to bring cam-lugs 14c, 17, and 18 to close contacts a a, (Z d, and 6, making a circuit from generator G, through 11' c 0 11- 10 117 to a, and from generator by wire 11-", through contacts (Z (Z 10 11 11" to (1, thus completing the circuit.

The invention is equally well adapted to a grounded circuit, as is illustrated in Fig. t of the drawings. It will be observed thatin this demonstration the eontactsff and their connections have been omitted because their service has been substituted by the ground at the transmitter. \Vhen the circuit-changing cam is at normal position in this arrangement, the cain- lu 13 and 16 are carried over the contacts a a and 1; 1;, closing them, and the line is by athrough wire 11' to plug, from plug to plug by ground, from plug to wire 21: to c, and from c to a by wire 11. through ringoff drop. lVhen the operator connects up the talking-circuit in this instance, he moves the circuit-changing cam from normal position to bring cam-lugs 13, l-t, and 16 to close contacts a a, I) I), and c 0, making a circuit from (1 by 11' to plug I, from c by wire 21" to plug, from d to by 11: and through Z) Z) by 11- 11" through transmitter to ground.

when the first ringing or call circuit is made, the operator moves the circuit-changing cam to bring cam-lugs 1(3 17 18 to close contacts 0 e, (Z (Z, and e e. '0 then have circuit from generator by wire Yb to contacts 6 c, thence by 10 to contacts 1; c, and by wires 10 and '21" to plug and ring-oil drop to ground.

lVhen the operator shifts the circuit-changing cam to the third position, being the second ringing position, the cam-lu s 1S and 17 are moved on the contacts (1(1' and 11 171 to ITO close them, and the circuit is made from generator by wire 205, through d d to a, then to w, to plug, and from a by to ring-off. drop and ground.

It is readilyunderstood that such of the upper series of contact-sprin gs remaining u nused in any of the circuits described lift by their resiliency into the depressions in the face of the circuit-changing cam, and while in this position for the time being form no part of the circuits in use.

The operation has been specifically stated in the description respecting the manipulation of the circuit-changing cam and in the statements relative to making and breaking the required circuits, and it will readily be perceived from these sources that the connection to the line of a called subscriber is made, as usual, by inserting the proper plug in the line to be connected therewith.

That I claim is 1. In an electric-oircuit-changing mechanism, the combination with a non-conducting cam having a series of recesses in its working face and teeth or projections between said recesses, of a series of pairs of contacts arranged one in advance of the other in a plane parallel with the said working face; one member of every pair at the same side of the series normally tending to spring away from its opposed mating member and toward the said working face of the cam, whereby as the cam is moved predetermined distances certain of said contacts will spring into the cam-recesses and certain others will be moved into contact with their mates to make and break the determined circuits, substantially as described.

2. The combination with the circuit-changin g cam herein described, composed of a nonconducting body formed with cam-lugs and depressions on its under face, supportingrods projecting from the ends of the body, a rack-gear on its upper face and a lever having a segmental gear meshing with said rack, of a series of pairs of contacts all controlled by said projections and depressions onthe cam.

The combination with a reciprocating circuit-changing cam having projections and depressions on its under face, of a series of pairs of contact-springs arranged in longitudinal series under the cam; whereby when the cam is moved longitudinally a predetermined cam and in the path of its two sets of projections and depressions.

5. In an electric-telephone-circuit-changing mechanism, the combination with the talking, call, and reply circuits having a series of pairs of contacts arranged side by side in the same plane, one member of each pair at the same side of the series tending normally to spring away from its mate, of a non-conducting cam having its working face overlying said series of contacts and formed therein with parallel series of recesses and intervening teeth or projections; whereby as the cam is moved predetermined distances certain of the contacts will spring away from their mates into the recesses while others will be moved by the cam teeth or projections into contact with their mates to break and make determined circuits, substantially as described.

6. In an electric-telephone-circuit-changing mechanism, the combination of a system of telephonic circuits having spring-contacts interposed therein, one set or series of said contacts consisting of arched springs, a reciprocatin g circuit-changin g cam formed with lugs and intermediate depressions on its under face,whereby any one of the determined circuits may be made and broken, and a lever to shift the circuit-changing cam.

7. In an electrio-telephone-circuit-changing mechanism, the combination with the lower contact-pieces a, b, c, d, e, f, having connection respectively to wires forming one side of the circuit, and the upper contact-springs a, b, c, d, e, andf, having connection respectively to wires forming the other side of the circuit, and tending normally to spring away from their mating lower springs of a longitndinally-reciprocating circuit-changing cam B made of a suitable non-conducting material, formed with lugs on its under face to normally hold the talking-circuit through contacts a a, c c, by depressing springs a, c, and lugs and depressions also on its lower face to open and close other circuits in the operative series by depressing certain of the upper springs and allowing others of such springs to move up into said depressions.

8. In combination with the contact-pieces a b 0 cl ef, the contact-springs a, b c d ef, and circuits connecting the same in series, of a circuit-changing cam composed of a suitable non-conducting material formed with lugs and depressions on its under face disposed to bear on and release the contactsprings and make and break determined circuits, and having a rack-gear on its upper face, sliding supports or bearings to sustain the circuit-changing cam, and a suitably-fulcrumed lever formed with a segmental gear to engage the rack on the circuit-changing cam to reciprocate it.

9. In electric-telepholie-switch circuits, the

circuitchanging cam herein described, comtransversely across the casing, a lever fulcruined in the casing and formed with a segmental gear On its lower end to engage the rack on the circuit-changing cam and Operate the same.

LOUIS JOHNS ON.

Witnesses:

GEORGE II. GORDON, MARION G. ANDERSON.

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