US592303A - Milo g - Google Patents

Description

(No Model.)

M. G. KELLOGG. MULTIPLE SWITGHBOARD. No. 592,303. Patented Oct. 26,1897.

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IINTnn STATES PATENT Prion.

MILO c. KnLLOeG, OF CHICAGO, ILLINOIS, AssIGNOR To THE KELLOGG swrrCnnoARD AND SUPPLY COMPANY, OP SAME PLACE.

MULTIPLE SWITCHBOARD.

SPECIFICATION forming part of Letters Patent No. 592,303, dated October 26, 1897.

Application tiled May 19,1887. Serial No. 238,723. (No model.)

T o all whom, t may concern:

Bc it known that I, MILO G. KELLOGG, of Chicago, (I'Iyde Parle) Illinois, 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, forming a part of this specification.

My invention relates to telephone-exchan ge systems in which the subscribers lines are normally grounded at the central office.

It consists, iirst, of a multiple-switchboard system of operating an exchange and testing at any board to determine whether any given line is in use, which system I shall hereinafter describe and claim in detail.

It consists, secondly, of a certain construction of spring-jack switch, which I shall h ereinafter describe and claim in detail, said switch being adapted for use in said multipleswitchboard system and in other systems of telephone-exchange switchboards.

It consists, thirdly, of a certain system of cords with plugs, apparatus, and circuits for answering, calling, switching, testing, and clearing out subscribers lines, which I shall hereinafter describe and claim in detail, said system being applicable to said multipleswitchboard system and to other systems of telephone-exchange switchboards.

In my multiple-switchboard system I place as many switchboards in the central Oflce as are found necessary or desirable in order to properly answer the calls and connect and disconnect the subscribers lines. On each board I place for each line which centers at the office a spring-j ack or similar switch having three insulated conta-ct -points, two of which are normally in Contact, said switch being adapted to receive a plug, and when the plug is inserted to disconnect the two points and connect one of them to the fiexible conducting-cord of the plug and the other one of them to the other contact-point of the three, and when the plug is withdrawn to again connect the contact-points which are normally in contact and disconnect the other point from either of them.

Figures 1n and lb of the drawings are front views of sections of two multiple switchboards to which the same wires are connected. Fig. 2 shows a complete diagram of the boards with their connections and all the central- Oiiice apparatus, circuits, and connections necessary to operate them according to my invention.

In the drawings like parts and apparatus are indicated by the same letters of reference.

In Fig. 2, A is a sectional View of the switchboard shown in Fig. l, as indicated by line CZ c, and A is a sectional view of the switchboard shown in Fig. lb, as indicated by line CZ e.

a h represent rubber strips on which the metal parts of the spring-jack switches are mounted. These strips may be long enough to receive any convenient number of springjack parts.

YZ l are rectilinear holes through the fronts and at thc edges of the strips adapted to receive the switch-plugs. The contact-springs g g are mounted to the rear of and are parallel to the holes Z Z to which they belong, as shown. The contact-points h 7i, on which the contact-springs or spring-levers g g normally bear,pass through the rubber strips, as shown, and each has a connecting-piece 7L anda contact-piece or extension 7L", as shown, extending to the front of the point and along the lower face of the switch-hole. In the front of the switch-holes and along their lower faces I place the contact-pieces /L' z', as shown. These pieces come in proximity to but do not touch the contact-pieces h, and they extend far enough to the front of their respective holes so that test-plugs may be applied to them. The switch-plugs are substantially as shown and as will hereinafter be described.

The several parts mentioned above are so made, shaped, arranged, and adjusted that when a switch-plug is inserted into a switchhole, as shown, it raises the spring-lever in the rear of the hole from the contact-point on which it normally bears, andthe flexible cord is connected to the spring-lever,whilc the contact-point h and the contact-piece t' are electrically connected through the medium of the piece m of thc switch-plug, which then touches c' and 7L" of the switch.

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' pointhand connecting-piece 7L of that switch a Each section of the' rubber strip, with 'its spring-lever, contact point, conta-ctpieces', and vthe. hole, all arranged and operating as above, may be called a spring-jack switch. The rubber strips are placed one above the other, as shown. The lower edge of one strip therefore provides the upper edges of the holes in the strip which is below it. The holes may be of any convenient shape adapted to the shapes and arrangement of the parts used.

Two subscribers lines are shown. They are marked line No. l and line No. 2. s s are the spring-jack switches of line No. l on the two boards shown, and r r' are the switches of line No. 2 on the two lboards shown. The circuits of the lines are as follows: Line No.

1, for instance, after entering the office passes4 iirst tospring-lever g of switch s', and thence through contact-point h and connecting-piece h of that switch and wire s to spring-lever g of switch s, and thence through contactand wire s/H to its annunciator w, and thence to ground. The contact-pieces t' and t' of switches s and s are connected together by wire 3", as shown. The other lines of the eX- change would be connected to their switches on the different boards and to ground in like manner, and the contact-pieces t' i which belong to the switches of a line would also be connected together in a like manner to that above. Other boards might be added' to the exchange, and the connections'of lines and the switches on the different boards would be th'ccords and adapted to be inserted into the line-switches.

m m are the metal pieces of the plugs, adapted to come in Contact with the springlevers 'g of a switch and connect therewith the cords of the plugs.

fm m are metal pieces'of the plugs, adapted to come in lcontact with the pieces h" and t' and connect them together.

n n are the rubber insulations of the plugs. The pieces m m extend to the bottom of the plugs, as shown, and are adapted to rest on the metal strip o, as shown, and normally connect the cords with the ground. The plugs should be inserted into the switches in such a position that the connections above described will be made. A plug is shown thus inserted in switch s in Fig. 2. Weights in the usual manner, or similar device's, may be vused to bring the bottoms of the plugs on o and form good connection from the cords to the ground.

Y is a looping-in switch.

g/ y and .c z are the contact-bolts of the switch, on which the'operator may at will place the pair of switch-levers.

7c is thecalling-key, constructed, connected, and operating as shown. A switch or similar device might be used in its place.

o is a clearing-out annunciator.

tis the operators telephone, B is her signalin g generator or battery, and B is her testing-battery. The circuits are substantially as shown.

The cross-piece between the levers of the switch 'Y may be of rubber, as is usual.

The letter G in each case represents a ground connection.

It is evident that when a switch-plug is placed in a line-switch, as described, (the other plug of the pair being used remaining on strip 0,) and the levers of the switch Y are placed on y y the line is disconnected from theground through its annunciator and is grounded through the operators telephone, and the contact-piece i of the line-'switch (and consequently all contact-pieces t' to which it is connected) is grounded through the switchboard-circuit and calling-annunciator ot' the line. in another line-switch, that line is also disconnected from the ground and the contactpieces t' of .that -line are also grounded and similar to the above and such as will be evij the two lines are connected together for conversation. The contact-pieces t of a line are normally (or when there is no plug in any `switch of. the line) disconnected from the ground.

The testing system is as follows: Vhen an operator desires to test any line at her board to see whether it is in use at another board, she moves the levers of the switch Y of a pair ofxcords to the bolts y y, and, placing. the piece m of one of the plugs of the cords on the test-piece t' of the line to be tested, she will hear a click inher telephone if the line is in use and will hear nothing if the line is not in use. The other plug of the pair may, when the testis made, remain on the strip o or may be in the spring-jack switch of another line. If the line tested is in use when the test is made, there will be a circuit from the ground to the other plug of the pair used, either through strip o or a subscribers line, through the telephone and testing-battery, the test-bolt at the board tested, the wire between that bolt and the test-bolt when the 'line is switched, and thence by the piece m of the plug by which the switching is done to the ground, and the test-battery, being thus in a closed circuit with the telephone, will occasion a click in the telephone when the test is made. If the line is not in use, there will be no such closed circuit and consequently no click in the telephone.

If the other plug of the pair is placed IIO The method of operating the exchange system at either board, including answering calls, making connections, sending signals, clearing out connections, duc., is such as will be apparent on an examination of the apparatus and circuits shown.

It is obvious that some features of my exchange may be used on lines having impedancecoils or annunciators in circuit-s permanently connected to line.

The testbolts of a line on the different boards maybe separate and distinct from the contact pieces of the switches which are crossed with the ground connection of the line, provided they are in electric connection with said pieces.

I claim as my invention and desire tosecure by Letters Patentl. The combination, with a strip of insulating material having a plug-hole through it, transverse to its front, of the metal parts of a spring-jack switch mounted thereon, said parts containing a spring-lever placed transverse to the front of said strip and in rear of the plug-hole, and two contact-pieces, normally insulated from each other, said con tact-pieces being mounted with their contactsurfaces in the same plane, and on the face of said plughole and one of said contactpieces being normally (or when a plug is not in said hole) in Contact with said spring, sub stantially as and for the purpose set forth.

2. A spring-jack switch with its metal parts mounted on a strip of insulating material, said strip having a plug-hole through it, transverse to its front, and said metal parts consisting of a spring-lever mounted in the rear of said plug-hole, and transverse to the front of said strip, and two contact-pieces normally insulated from each other, said pieces being mounted with their contact-surfaces in the same plane and on the face of said plughole and one of said contactwpieces being normally (or when a plug is not in said hole) in contact with said spring, in combination with a switch-plug with two contact-surfaces, insulated from each other, and one of which is connected with a switch-cord, said plug being adapted to be inserted into said hole, and when inserted to disconnect said spring from said normal contact with one of said contactpieces, and connect said spring with said switch-cord, and at the same time electrically connect together said two contact-pieces, and insulate them from said lever and switchcord, substantially as and for the purpose set forth.

3. A spring-jack switch with its metal parts mounted on astrip of insulating material, said strip having a rectilinear plug-hole through it, transverse to its front, and said metal parts consisting of a springlever mounted in the rear of said plug-hole, and transverse to the front of said strip, and the two contact-pieces normally insulated from each other, both pieces being mounted with their contact-surfaces in the same plane, and on one of the faces of said rectilinear plug-hole, and one of said contact-pieces being normally (or when a plug is not in said hole) in contact with said spring, in combination with a switch-plug adapted to lit said plughole, and having two contact-pieces insulated from each other, and to one of which is connected a switch-cord, said plug on its insertion disconnecting said spring-lever from said normal contact with one of said contact-pieces, and connecting it with said switch-cord, and at the same time electrically connecting together said twocontact-pieces and insulating them from said lever and switch-cord, substantially as and for the purpose set forth.

4. In a spring jack switch, the contactpieces h and t' mounted along the face of the switch-hole, and with contact-surfaces in the same plane, in combination with the springlever g, substantially as and for the purpose set forth.

5. In a spring-jack-switch device, the contact-piecesh and i, mounted along the face of the switch-hole, and with contact-surfaces in the same plane, and the spring-lever g, in combination with the switclrplug, with contact-pieces m and m', substantially as and for the purpose set forth.

6. In a spring-jack switch, the combination of a contact point or piece having a metal surface in line with a face of the switch-hole and extending toward the front of and along said hole, a spring contact-lever in the rear of said hole and transverse to it, and normally or when no switch-plug is in the hole, in contact with said contact-point, anda contact-piece, normally insulated from the other pieces, mounted on a face of said hole with its contacteur-face in the same plane as said metal surface, and adjacent to it and reach` ing to or near the front of said hole, substantially as and for the purpose set forth.

7. The combination, with a spring -jack switch having two contact-points which are normally (or when no plug is in the switchh'oleYin contact, and a third contact-point which is normally insulated from the other two, a telephone-line connected to one and a ground connected tothe other of said contact-points, which are normally in contact, of a switch-plug and a switch-cord, said plug having two insulated contact-pieces to one of which is connected said switch cord, and adapted, on the insertion of the plug into the switch-hole to separate and insulate the points which are normally in contact, connect the line contact-point with the cord, and said third contact-point with thc ground contactpoint.

8. In a multiple-switchboard exchange, a closed test-circuit for a ground-circuit line which is in use, said circuit including, in the order named, a ground connection, a test out- (it and plug, a test contact-piece for the line temporarily connected to said plug for testing, thence to a contact in some other switch of the line where the line is switched for use,

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and thencey to a contact directly connected thereto, mounted on the plug in said switch, but not then connected with the circuit of theline, and thence to a second switch-contact connected to said plug-contact while the plug is in the switch Vbut otherwise insulated from. said circuit connection,thence to ground.

9. In a multiple-switchboard exchange, a closed test-circuit for a ground-circuit line which isin use, said circuit including, in the order named, a ground connection, a test instrument and plug a test contact-piece for .the line temporarily connected to said plug for testing, thence to a circuit connection connecting all the contacts ot' said line together, thence toa contact in some other switch of the line where the line is switched for use, and thence to a contact directly connected thereto mounted oni the plug in said switch but notthen connected with the circuitof the line, and thence to alsecond switch-contact connected to said plug-contact while the plug is in the switch but otherwise insulated from said circuit connection, thence to the cut-0R portion of the line through any pair or pairs of normally closed jack-contacts which may be in said portion, andl to ground, and means in said test-circuit to cause said test instrument to'respond when connected to said closed test-circuit.

10; In a multiple-switchboard exchange, two ormore multiple boards, switches, one for eachline oneach board, each switch having three contacts, atest-contact, a contact connected'to the ground, and a contact connected to the line, said"` test-contacts being electrically` united butr disconnected normally from thelother contacts, and plugs at eachboard adapted' to be inserted into the switches and each having a conducting-piece adapted to connect said test-contact and said groundcontact ofthe switch bycross-connecting or electrically bridging said/test and: ground contacts of the switch without connecting said test-contact to the line-circuit.

v 11.` In a multiple -switchboardl exchange, two or more switchboards, switches, one for each line on two or more boards, each switch having a test-contact, saidV test-contacts for each linebeing'connected together and. normally ung'rounded, a contact connected to the ground, anda contact connected to the line, switch-plugs-at each board, eachfplug adapted to'be inserted into each switch at each board and each having two insulated contacts, onel the test and ground contacts of the switch in i whichitis inserted and thereby cross-connect or electrically bridge said test and said ground contacts.

l2. Ina multiple-switchboard exchange, test-contacts one at each board, foreach line, the test-contacts of each line being electrically united together and normally ungrounded, a common grounded conductor, a circuit connection between said test-contacts and said common grounded conductor, normally open but closed or bridged by a plug-contact adapted to form apart of said circuit connection while the line is switched for use, a test outt' connected on one side to said conductor, and on the other adapted to be connected to atest-contact for testing, and atest-battery for the test-circuit when established.

13. Inl a multiple-switchboard exchange, switches, one at each of two or more boards for each line, a common conductor, a contact in each switch normally insulated therefrom, a circuit connecting said contacts, one additional contact, in each switch connected to said common conductor, a bridgingv or crossconnecting contact mounted on a plug, adapted while the line is in use to be directly'conynected to said contacts and thereby electrically unite them, a test outfit connected on Aone side to said common conductor and on the other adapted to be connected to a testcontact for testing and a test-battery for said test-circuit.

14. In a multiple-switchboard exchange,

line-circuits, each connectedto a jack at each board, each jack provided withv a stripof insulating material having a plug-hole through it, transverse to its front, of the metal part-s of a-spring-jack switch mounted thereon, said parts containing a spring-lever placed transverse to the front of said strip and inthe rear of the plug-hole, and two contact-pieces, norvmally insulated from each other, said contact-pieces being mounted withl their contactsurfaces in the same plane, and on the face in said hole in contact with said spring, a bridging or cross-connecting insulated contact mountedupon a plug and adapted when said plug is insertedv into a line-jack to be directly connected to both of said contacts thereby electrically connecting them, a test receiving instrument connected for testing, on one side to said common conductor and on the other to a plug or device adapted to be applied tothe other contact-piece.

MILO G. KELLOGG.

Witnesses:

WALLACE L. DE WOLF, FRA-Nens D. KELLoGG.

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