US542262A - Multiple switchboard for telephone-exchanges - Google Patents

Description

N0 Model'.)

M. G. KELLOGG. MULTIPLE SWITGHBOARD FOB TELEPHONE EXCHANGES. N0. 542,262.

Patented July 9, 1895.

UNITED; STATES PATENT OFFICE.

- MILO e; KELLO'GG, or emcee-0', ILLINOIS.

MULTIPLE SWITCHBOARD FOR TELEPHONE-EXCHANGES.

' SPECIFICATION forming part Letters Patent No. 542,262, dated July 9, 1895.

' Application filed December 21, 1889. Serial Ho. 884,519. (No model.) i

To all whom itmay concern:

Be it 'knownthat I, MILO G. KELLOGG, of Chicago, Illinois, temporarily residing at Stuttgart, in the Empire of Germany, have invented certain new and useful Improvements in Multiple Switchboards for Telephone-Exchanges, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, formin g a part of this specification.

My invention relates more especially to the multiple-switchboard system described in my Patent No. 308,315, dated November 18, 1884-, and similar systems.

' It consists of a "compound spring-jack switch, hereinafterdescribed and claimed, designed to be used in the switchboards of the central office of a telephone-exchange.- I The organization whereby the two pairs of contacts areoperated on the insertion of aswitohplug is, however, novel aside from any pat ticular system to which the switch may be adapted, and though I show and describe the switch in connection with a particular system I do not limit myself to the special connection of the contacts in my switch, whereby the desired operations in the particular system shown herein are accomplished.

In the accompanyingdrawings, representingmy invention, Figure 1 represents a side view of sections of two multiple switchboards, to which the same lines are connected, and a diagram of the local circuits, connections, and

A A are broken sectional views of the frameworks of the switchboards adapted to receive the spring-jack switches.

.lis the metalfraine of the switch, having a hole through its front and adapted to receive a switch-plug and operate the switch parts.

d is a metal contact screw or point passing parts are indicated b through the frame Z andinsulated from it'by the insulation 0, which also passes through Z.

c is a contact spring or piece, which is also insulated from the metal frame I, and is in contact withthe point b of screw d when the wedge or plug is not inserted 'into the switch. When the wedge or plug'is inserted into the switch the contact between point I) and spring e is broken, as shown in board A.

b and e are a-pair'of contacts, and as I use them in opening and closing a subscribersv telephone-line I call them the main line contacts of my switch.

7a is a connecting-piece in electric connection with screw d.

his a contact-point, in this insiance ,connected with the metal frame of the switch, as shown. I

f is a' contact spring or piece, which is insulated from the frame I, andalso from the contact-spring e, and is in contact with the point h when the wedge or plugis inserted into the switch. When a wedge or plug is not in the switch, the contact between the point h and springf is open, as shown.

h and f are a pair of contacts, and as I use them-in opening and closinga local circuit in my multiple switch-board system,I call them l is a connecting-piece in electric connection with the framework'l.

m',m", and m areinsuIating-pieces,which insulate springs e and f from each other and from the frame L. An extension of Z passes through these pieces and has a screw-thread cut on it. n is a nut which fits this thread and holds the parts in place, as shown.

I have shown a. plug inserted in to the righthand switch shown on board A.

Fig. 3 shows a wedge or plug adapted for use with my spring-jack switch. 0 is the handle of the plug, and ismade of some insulating material, as hard rubber. C is a solid metal cylinder with round end, as shown.

C" is a rubber cylinder surrounding the metsl cylinder, except at the rounded end, as shown. D'is a flexible insulated conductingcord in electric connection with the metal cylinder C'through the metalstrip E.

It will be seen that when there is no plug in the switch there is electric contact between the points b and" e, and that the points h and fare open to each other, and also that the switch-frame is insulated from all these points except the contact h thereon.

It will also be seen that when a plug is in the switch the electric cbntact between 12 and eis broken, and that the contact between 72 andfis made, and that the metal cylinder of the plugis in contact with the spring e and that the metal switch-frame is insulated from the parts 6 e and the plug-contact, 'and is in connection with f through the contact h.

The point I) and spring e,,with the plug and cord, constitute the main-line switch in my system. The point It and spring f, whereby the local circuit is automatically closed by the insertion of the plug for switching the main line, constitute a local circuit-closer. The metal switch-frame Z, being always insulated from the other working parts of the switch, except the contactf, when a plug is inserted, and from the plug, except through the arrangement of circuits hereinafter shown, constitutes a test-plate in my system of multiple switchboards, and I call its front end, which extends to the front of the board, a test-contact, and this test -contact is in electrical connection with the point h.

T are the test-plugs, and t are the test-receiving instruments, one plug and one instrument for each switch-board.

B .B are test-batteries.

The connections of the main lines through the main-line contact-points on the several boards are as shown.

I have not represented the operators cord system and apparatus indetail, as well-known forms'bf apparatus may be used for switching .theJines.

The localtest'circuits and connections are as follows: All the contact-pieces ff of the switches on the several boards are connected together and are connected to one side of each of the testreceiving instruments. All the metal frames of the switches of aline (to which are electrically connected the contactpicces h of their respective switches) are connected together. To the other side of each test-receiving instrument from that mentioned above is connected its test plug'or device by a cord of such length that the plug can readily be brought into contact for testing with any metal piece lat its board. In the circuit of each test-receiving instrument between its test-plug and the point where it is connected with the group of contact'piece'sf f of the exchange is an electric battery.

When a line is tested at any bo'ard by the test-plug being applied to the metal frame 1 of the line tested and the line is switched at any board the test-receiving instrument will sound or respond, the test-circuit being complete through the frame of the switch tested to the frame of the switch that is switched or plugged and its pair of local contacts hf to one side of the test-battery B. \Vhen on the test being made the line is not switched there is no complete circuit, none of the contacts h f being closed, and the instrument will not sound or respond. The operator can there fore determine on testing whether or not any line is switched for use.

By the construction and arrangement of the parts as shown and described above the switch and test apparatus is less complicated and is morecondensed than is found in other apparatus constructed for use in multipleswitchboard systems which have independent local test-circuits for the lines.

I claim as my invention 1. A spring jack switch, adapted to receive a switch-plug, consisting of a metal frame through the frontof which is the switch hole, a contact spring or piece placed with its length parallel to the axis of the hole, a secend-contact spriuginsnlated from and parallel with the first contact-spring and operated by it to be pressed into contact with 'a contact point or piece while a plug is in the switch hole, substantially as set forth.

2. A spring jack switch, adapted to receive a switch plug, consistizg of a metal frame through the front of which is the switch .hole, a contacbspring or piece insulated from the metal frame and placed with its length parallel to the axis of the hole, and a second contact spring or piece insulated from the first contact-spring and normally insulated from the metal frame, placed parallel to said first spring and operated by it to be pressed into connection with said metal frame while a plug is in the switch hole, substantially as set forth.

3. A spring jack switch,adapted to receive a switch plug, consisting of a metal frame through the front of whichis the switch hole, a contact -poiut insulated from the metal frame, a contact-spring or piece. insulated from the metal frame, placed with its length parallel to the axis of the switch hole and nor mally in contact with said coutact-point,and a second contact-piece or spring insulated from the first contact spring normally-insulated from the metal frame, and placed parallel to the first spring, said first spring being operated by the plug, on its insertion, to be pressed awayfrom its normal connection with its contact-point and to press the other contact -piece into connection with the metal frame, substantially as set forth.

4. In a spring jack switch, acontact-spring or-piece placed with its length parallel to the axisoftheswitch hole, a second contact-spring or piece insulated frourand parallel with the first contact spring and a contact-point nor mally insulated from both contact-springs said switch being adapted to receive a switch plug, which on its insertion, moves the first point, substantially as set forth.

In a spring jack switch, a contact-spring or piece placed with its length parallel to theaxis of the switch hole and normally in contact-with a contact-point, a second contactspring or piece placedparallel to and insulated from. the first spring, and another contact-point normallyinsulated from the rest, said switch beingadapted to receive a switch plug, which on its insertion, moves the first contact-spring away from its contact-point -with which it is normally in contact, and

presses the second contact spring into connection with said othercontact-point, substantially as set forth. I

6. In a spring jack switch, a metal frame extending to the front of the' switch board and through the front of which is a switch hole,acontact-spring or piece placed with its length parallel to the switch hole, a second contact-spring or piece insulated from and parallel with the first contact-spring and normally insulated from the metal frame, said switch being adapted to receiveaswitch plug which, on its insertion, moves the contactspring, and said contact. spring when thus moved presses the contact-piece into connection with the metal frame, substantially as set forth.

7. Ina spring jack switch, a metal frame extending to the front of the switch board and through the front of which. is a switch hole, a contact spring or piece placed parallel to the switch hole and insulated from the metal frame a con tact point with which said.

hole, a second contact spring insulatedv from and parallel with the first contact spring, 3;

- contact-point normally insulated from the second contact-piece and electrically connectcd with a' metal test contact piece on the front of the switch board, said switch being adapted to receive a switch-plug which on its insertion, moves the first contact-spring and presses the second contact spring into con-- nection with said as set forth. .9. In a'spring jack switch,a contactspring placed with its length-parallel to the switch hole, a contact point with which the spring is normally in contact a second contact spring or pi ce'insulated from the firstcontact spring contact-point, substantially and placed parallel to it, and a contact point ndrmally insulated from the second contact.

spring, and a. test-piece placed on the front of the switch board with which the last named .contact point is el'ectrically'counected, said switch beingadapted to receive a switch-plug which on its insertion, moves'the firstspringaway from its normal connection'withits contact-point and presses the second con tact-' piece into connection with itscontactpoint,

substantially as set forth.

10. The combination of the frame-work hav,

mounted on said fi-ame-wo'rkjwith one end in the hole andhaving insaid end a switch hole" for the reception of aswitch plug, two insulated contact-pieces or springs carried by said frame,an insulated contact point also carried by the metal frame and with which one of said springs is normally in contact, and another contact point also carried by said metal frame with which 'the other spring is normally out of contact, the arrangement being such that when a .switch plug is inserted one contact spring moves out of contact with the point with which it is normally in contact, and the other spring moves into contact with the point with which it is normally out of contact. X

11. The combination of the frame-work having a. hole therein for the-insertion of a switch plug, two contact-pieces or springs insulated from each other, arranged in the rear of the frame-work parallel, or substantially so, with the axis of the switch hole, a contact point with which one of the springs is normally in contact and another contact point with which the other spring is normally out of contact, the arrangement being such that when a switch plug is inserted one spring is pressed out of contact with its contact-point and the otherv inserted into the switch hole, one spring is pressed out of contact with the point against which it normally bears, and the other spring is pressed into contact with the point with which it is normally out of contact.

13. The combination, of theframe-work having a hole therein for the insertion of a switch plug, two contact pieces or springs, insulated from each other, arranged in rear of the framework, parallel, orsubstantially so, with the axis of the switch hole, an insulated contact point upon which one ofthe springs normally bears, another contact-point with which the other spring is normally out of contact, and

IIO

a metal test piece or contact at the front of the switch board with which piece the last named contact is in electrical connection.

14. Inaspringjack switch the combination, with the frame work of theswitch board, two

insulated contact-pieces or springs arranged in 1.;nr of the frame-work parallel with each other, or substantially so, and at right angles to the plane of the face of the frame-work, a contact point against which one of the springs normally bears, and another contact point with which the other spring is normally out of contact, of a. switch plug, adapted to be inserted into the switch, the arrangement being such that when the plug is inserted one spring is pressed out of contact with the contact point against which it normally bears, and the other spring is pressed into contact with the contact point with which it is norinnlly out of contact.

In witness whereof I hereunto subscribe my name this 29th day of November, 1889.

MILO G. KELLOGG. \Vitnesscs:

EMIL AB'ENHEIM, ll'lARGARETHA PRIEIIL.

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