US427087A

US427087A - kelloaa

Info

Publication number: US427087A
Authority: US
Publication date: 1890-05-06
Anticipated expiration: 1907-05-06

Description

(No Model.) a 2 sheet -sheet 1. 1VI. G. KELLOGG. MULTIPLE SWITCH BOARD FOR TELEPHONE EXCHANGES.

No. 427,087. Patented May 6, 1890.

(No Model.) I 2 Sheets-Shed 2. M. G. KELLOGG.

MULTIPLE SWITCH BOARD FOR TELEPHONE EXCHANGES. I No. 427,087. Patented May 6, 1 890.

UNITED STATES PATENT FFICE.

MILO G. KELLOGG, OF CHICAGO, ILLINOIS.

SPECIFIQATION forming part of Letters Patent No. 427,087, dated May 6, 1890.

Application filed June 28,1888- Serial No. 278,423. (No model.)

To all whom it may concern:

Be it known that I, MILO G. KELLOGG, of Chicago, Illinois, have invented certain new and useful Improvements in Multiple Switch- Boards for TelephOneEXchanges, of which the following is a full, clear, concise, and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention is an improvement in the 1nultiple-switch-board system described in my application for patent filed December 8, 1887, No. 257,317, now patented, No. 424,310, dated March 25, 1890.

The-principal advantages obtained in the system which I shall now describe as com-' pared with the system described in said application are a reduction in the number of switch-plugs and cords required at the central office and in the number of calling-keys or amount of signal apparatus required at the subscribers stations.

In carrying out my invention I divide the subscribers lines which center at an exchange-office into two divisions or classes. I also divide the switch-boards required for the operation of the exchange into two sections. On each board of one section Iplace a springjack or similar switch for each line of one class, and for each of said lines I also place on a switch-board of the other section a spring-jack switch. On each board of the other section I also place a spring-jack or similar switch for each line of the other class, and for each of said lines I place on a switchboard of the first-mentioned section a springjack switch. The said spring-jack switches of the lines, of which there is only one in each section for the line, are distributed in approximately equal numbers among the switch-boardsof their section. These switches, as will hereinafter appear, are to be used in answering their subscribers calls and in con-' necting their subscribers lines, in answer to their calls, to other subscribers lines. They may therefore be designated as answering spring-jack switches. The other switchesof the exchange (those of which there are one for each line on each board of its section)are used in making calls to and connections with their lines when the lines are wanted. They may therefore be designated as calling spring-jack switches. Part of the lastdescribed switchesto wit, one for each linemay also be used in answering their subscribers calls and in connecting their subscribers lines, in answer to their calls, to other subscribers lines. Such switches may also be designated as answering spring-jack switches, and such switches of a section should be distributed in approximately equal numbers among the boards of a section. From the above it will appear that each line of an exchange has acalling-switch on each board of a section and an answering-switch on one board of both sections, and that one of the calling-switches of a line is also an answering-switch of the line. The number of switches used for a line is therefore one more than the number of switch-boards of the section on which are its calling-switches. In some arrangements it might be found convenient to use a special answering-switch for a line in the section in which its callingswitches are located. Should this be the case, they can readily be provided.

For each line I provide two signal-receiving instruments or annunciators at the central office, whereby the subscriber may signal to the central office. These annunciators of a line are located where the answeringswitches of the line are located, and consequently at two boards of the exchange, one

board in each section. The operator at each of these boards may therefore know when the subscriber has signaled her.

On each board I also provide test circuits and apparatus, whereby the operator may test any line which is connected to all the switchboards of the section to which her board belongs, and determine whether or not the line is switched for conversation at any other board of the exchange.

On each board I also provide operators systems of pairs of cords with plugs, including operators telephone, calling-generator, switches, and circuits for same, one system for each operator, of any usual form and construction, whereby the operator may conveniently connect her telephone into circuit with any line which has its answering-switch and signal-receiving apparatus at her board, and

may connect said line for conversation with any line which has its calling-switch at her board.

At each subscribers station I provide signaling apparatus, whereby the subscriber may signal to the operators at the two boards where the signal-receiving apparatuses of his line are located. I prefer to have the subscribers signaling apparatus and the signalreceiving apparatus of his line at the two boards so constructed and placed with reference to each other that the subscriber may signal to either of the boards at will without his attracting the attention of the operator at the other board.

At each subscribers station is also the usual telephone apparatus and circuits adapted to the particular exchange system employed. The lines may be divided into approximately equal classes and the boards into approximately equal sections.

It will be seen from the above general description of the system thata subscriber may signal to one section of the exchange and may obtain connection with any line of the exchange which has its calling-switches in that section, and by signaling to the other section may obtain connection with any of the other lines of the exchange.

In the usual form of multiple switch boards one spring-jack switch is required for each line on each board of the exchange. It is apparent that with the organization described above only about one-half that number of switches would be required.

My invention as a Whole is applicable to all the various systems of lines and of testing which may be employed in multiple-switchboard systems.

The systems of apparatus and of testing which I have shown in the drawings, and which I will now describe in detail, are adapted to a system of single-circuit lines where the lines are normally grounded at the central office and at the subscribers stations.

In the drawings, Figures 1, 1, 1 and 1 represent front views of sections of four switch-boards of a multiple exchange system embodying my invention, the two former belonging to one section of the boards and the two latter to the other section of the boards. In Fig. 2, A, A 13, and B represent sectional views of said boards, respectively, each as indicated by the line d c, with all the 1nain-lin-e apparatus and circuits necessary to illustrate my invention. Fig. 3 shows a diagram of an operators cord system which may be used in connection with either board. Fig. 4 shows a diagram of an operators test apparatus which may be used in connection with either board. Fig. 5 shows in diagram the subscribers-station apparatus. Fig. 6 is an end View of the generator-shaft at the subscribers station, with two contact-springs bearing one on each side of the shaft, and of the insulated contact-piece of the shaft. Fig. '7 shows in detail the calling-annunciators used at the central office.

I In the drawings like parts and apparatus in the different figures are indicated by the same letters of reference. G in each case represents the ground-connection.

In the drawings, 0 c, &c., represent rubber strips, on which the metal parts of the springjack switches are mounted. These strips may be long enough to receive any convenient number of spring-jack parts.

Z Z are rectilinear holes through the fronts of and at the edges of the strips adapted to receive the switch-plugs. The contact-sprin gs g g are mounted to the rear of and are parallel to the holes H, to. which they belong, as shown. The contact-points 7L 72., on which the contact-springs or spring-levers g'g normally bear, pass through the rubber strips, as shown. These contact-points piece 7L, and also a contact piece or extension 7L, as shown, along to the front of the point and along the lower face of the hole. Toward the front of the switch-holes and along their lower faces I place the contact-pieces 'L' 2', as shown. These pieces come in proximity with but do not touch the contact-pieces h" of their switches, and 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 it raises the spring-lever in the .rear of the hole from the contact-point on which it normally bears, and the flexible cord of the plug is connected with the spring-lever, while the contact-point and the contact-piece 'L' of the switch are electrically connected through the medium of the piece mof the switchplug, which then touches both i and h of the switch.

Each section of the rubber strip, with its spring-lever, contact-point, contact-pieces, and the hole, all arranged and operating as above, and as shown, maybe called a springjack 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 shape and arrangement of the parts used.

The calling-annunciators or signal-receiving instrumentsone for each line in each of the two sections of the exchangeare marked to in the drawings, and those which are shown are located at the boards where the calls of their lines are to be answered. These annunciators are polarized annunciators, and their construction is shown in greater detail in Fig. '7. Each of these annunciators responds or indicates when one polarity of current passes over its line and does not respond when the have each a connecting- ITO the piece 0, and thereby form connection between the cords and the ground. The parts of an operators cord system should be conveniently mounted at the board where it is to be used, so as to allow the required operations of the system. The connections of the system are substantially as shown. The operatidns of the system in answering calls, making connections, and attending to the other exchange operations will be apparent to those skilled in the art.

The operators test system shown in Fig. 4 consists, essentially, of a test wire or circuit in which is a test-receiving instrument (which may be a magneto-telephone) and a suitable test-battery, said test wire or circuit being grounded at one end and terminating at its other end in a test-plug with a flexible conducting-cord adapted to be brought into connection with any contact-piece t' of the board where the test system is located. In the figure, T is the test-plug, I is the test-receiving instrument, and B is the test-battery. The operator at each board should be provided with one cord system and one test system. scription of the apparatus and circuits which has been given that when any line of the exchange is switched for conversation at any board where it has a switch all the contact pieces it of all the switches of the line are crossed or connected with the ground, such connection being due to the crossing of the piecei with the piece h of the switch when the connection is made and the fact that all the pieces it of the switches of a line are connected together. lVhen the line is not switched at any board, all the pieces 2' 2' of its switches are open to the ground. \Vhen an operator, therefore, brings her test-plug T in contact with piece 'i at her board, and the line to which it belongs is switched at another board, there will be a complete circuit established in which is her test-receiving instrument and test-battery, and her instrument will sound. If the line is not switched at any board, there will be no such complete circuit and the instrument will not sound. The operator can thereby determine whether or not the line is in use at another board.

The apparatus shown and described will enable an operator to test only such lines as have their switches on her board, and these are approximately about one-half the lines of the exchange. It is evident that facilities for testing such lines are sufficient, as it is only with them that she is required to switch to when they are called.

To carry out the organization it is necessary that each subscriber should be able to determine whether or not he is to press his calling-key when he calls for connection with any other subscriber. To accomplish this the subscribers whose lines belong to one class may be indicated by some designation in the exchange list-as, for instance, their numbers may all be prefixed by the letter A. The

It will be seen from the desubscribers which belong to the other class may also be designated in some manner-as, for instance, by the absence of any prefix or special mark. All the calling-keys might be marked with the letter A. The apparatus and lines could be so connected that when a subscriber desires connection with any line designated by the letter A he is to operate his generator while pressingon his calling-key marked A. WVhen he desires connection with any line of the other class, he is to operate his generator Without pressing on the calling-key. This system of calling either board at will to which the subscriber may be connected therefore requires but one calling-key, and it requires the subscriber to press on the key only when he is calling one board.

It will be seen from the description of the main-line circuits and apparatus and of the operators cord system as given that when twosubscribers lines are switched together at any board of the exchange by the insertion of the two plugs of any pair of cords into the switches of the line at that board the two calling-annunciators of each line are cut off or disconnected from the circuits of the line, and the operator may, by the use of the switch Y, loop the clearing-out annunciator 1) into the combined circuit of the lines. The number of pairs of cords needed for the system will depend on the number of connections which are liable to be required at one time in the exchange. As a general thing only about one pair of cords to every eight or ten subscribers lines will answer.

I claim as my invention and desire to secure by Letters Patent- 1. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sect-ions, switches for said lines, a switch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and on a board of the first-mentioned section, and pairs of switch-plugs with cords, whereby an operator at anyboard may by inserting the two plugs of a pair into the two switches of,the lines'eonnect together any two lines which have their switches at her board, substantially as set forth.

2. I11 a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, switches for said lines, aswitch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and on a board of the first-mentioned section, annunciators for said lines, tWo annunciators for each line, one located at a board in the section in which its line has a switch 011 each board and the other located at the board in the other section where the switch of the line is located, and pairs of TOC other polarity of current passes over the line. The two annunciators of any given lineone in each section of the exchange-are so constructed and so connected into the circuit of their line that one of them will respond to one polarity of current and the other will respond to the other polarity of current.

I have represented two lines as connected to the boards of the exchange, one line of each class. One line is marked line A and the other is marked line 13'. Line A after entering the office, passes successively through its switches on boards A and A thence through its answering-switch, (marked ct on board B',) in each case going to the spring-lever first, thence through its annunciators w w on boards A and B, and thence to the ground, all as shown. Line B, after entering the office, passes successively through its switches on boards B and B thence through its answering-switch, (marked Z) on board A in each case going to the spring lever first, thence through its annunciators w w on boards A and B and thence to the ground, all as shown. All the contact-piecesi dot the switches of a line are connected together, as is shown. The lines are also grounded after passing through their subscribers station apparatus.

In the diagram of the subscribers station apparatus shown in Fig. 5, 1 is the telephoneswitch, 2 is the signal-receiving bell, 3 is the calling-generator, i is the operators telephone, and 7c is a calling-key. The generator is constructed with the usual automatic device, whereby it is shunted or switched from the line-circuit while not operated. The insulated contact-piece on the shaft of the armature, to which is connected one end of the armature-wire, and which conducts the generated current to the line through the stationary spring-contact (or contacts) provided for it, is a half-circle, the remaining part of the circle being an insulation, as shown. I provide two stationary spring contact-pieces, as shown, each bearing on the diametrically-opposite part of the circle of the shaft of which said. insulated contactpiece is a part. The key is provided with two pairs of contact-points, as shown, one pair being normally closed and the other pair normally open, and when the keyis depressed the normally-open pair of contacts is closed and the normally-closed pair is opened. The connection of the key to the contact-sprin gs of the generator and to the line-circuit is as follows and as shown: The spring-lever, which formsone of the contacts of each pair of contact-points, is connected with one side of the main-line circuit. The two other contact-pieces of the pairs of contact-points are connected to the two contact-springs, respectively. As stated above, one end of the armature-wire is connected with half-circle contact-piece 011 the generator-shat t, 011 which the springs alternately bear when the generator is being turned. The other end of the armature-Wire is connected with the other side of the main-line circuit. The automatic shunt device mentioned before may shunt that part of the circuit containing the armature-wire and the key when the generator is not being turned.

It is well known that when magneto-generators are turned and operated a current'of one polarity is generated during one half of the revolution of the armature and a current of the other polarity is generated during the other half of the revolution of the armature. It will be apparent from the description of the subscribefis-station apparatus which has been given, and from the circuits, that when. the generator is being operated and the key remains in its normal position the armaturewire is in circuit through one of the contactsprings, and that only, and a current of one polarity will be sent to the line, and that when the generator is being operated and the key is depressed the armature-wire is in circuit through the other contact-spring, and that only, and a current of the other polarity will be sent to the line. The subscriber can therefore at will send currents of either polarity to line, as he does not or does press on the calling-key. \Vhen his line is provided with two calling-annunciators which respond to currents of opposite polarity, as indicated, one annunciator being located ata board in one section of the exchange and the other annunciator being located at a board in the other section of the exchange, he can at will call the operator at either board and not disturb the other operator.

The operators cord system shown in Fig. 3 has a pair of cords with switch-plugs, acalling-key, a looping-in switch, and a clearingout annunciator for the same and the usual telephone and calling-generator. Only one pair of cordsand plugs with its special apparatus is shown. Others could be added in a manner which will be apparent to those skilled in the art. I) D are the switch-plugs connected to the cords and adapted to beinserted into the line-switches. m m are the metal pieces of the plugs, adapted to come in contact with the spring-levers g g of the switches and connect the levers with the cords of the plugs. m m are metal pieces of the plugs, adapted to come in contact with the pieces h" and 1'. of the switches when the plugs are inserted into them and connect said pieces together. Y is the looping-in switch for the pair of cords, and v is the clearing-out annuncia'tor. B is the calling-generator, and 25 is the operators telephone. \Vhen the plugs are used, they should be inserted in such a position as to make the connections as above described. a '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 0, as shown, and normally connect them with the ground. WVeights in the usual manner or similar devices may be used to bring the bottoms of the plugs onto switch-plugs with cords at each board, whereby an operator at the board may by inserting the two plugs of a pair into the two switches of the lines connect together any two lines which have their switches at her board, substantially as set ,forth.

3. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, switches for said lines, a switch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and on aboard of the first-mentioned section, signaling apparatus whereby any subscriber may at will signal to the operators at two boards of the exchange, one boardin each section, and one of said boards-that one on which is the switch of the subscribers linein the section where there is but one switch for the line, and pairs of switch-plugs with cords at the boards, whereby the operator at any board may by inserting the two plugs of a pair into the two switches of the lines connect together any two lines which have their switches at her boards, substantially as set forth.

4. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for saidlines divided into two sections, switches for said lines, a switch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and on a board of the first-mentioned section, polarized annunciators for said lines, two for each line and in the circuit of their line, one of the annunciators of a line indicatingwhen a current of one polarity passes through it and the other indicating when a current of the other polarity passes, the two annunciators being located at two boards of the exchange, one board in each section, and one of said boards-that one on which is the switch of the linein the section where there is but one switch for the line, a signaling-generator at each subscribers stat-ion, switching apparatus whereby any subscriber may at will send a current of either polarity over his line, and pairs of switch-plugs with cords at each board,whereby the operator at any board may by inserting the two plugs of apair into the two switches of the lines connect together any two lines which have their switches at her board, substantially as set forth.

5. In atelephone-exchange system, the combination of telephone-lines divided into two classes, multiple switclrboards for said lines divided into two sections, switches for said lines, one switch for each line of one class on each board of one section and one switch for each line of the other class on. each board of the other section, said switches being for making connections with their-lines when they are called for, and which may therefore be designated as calling-switches? also two switches for each line, one switch on a board of each section to make connection with its line when its subscriber calls, and which may therefore be designated as an answeringswitch, and pairs of switch-plugs with cords at each board, whereby the operator may by inserting the two plugs of a pair into the two switches of the lines connect any line which has its answering-switch at her board with any line which has a calling-switch at her board, substantially as set forth.

(3. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, switches for said lines, one switch for each line of one class on each board of one section and one switch for each line of the other class on each board of the other section, said switches'bemg for making connections with their lines when they are called for, and which therefore may be designated as calling-switches, also two switches for each line, one switch on a boardof each section to make connection with its line when its subscriber calls, and which may therefore be designated as an answeringswitch) two annunciators for each line, one annunciator located at a board in each section and at the board of the section where the answering-switch of the line is located, and pairs of switch-plugs with cords at each board, whereby the operator may by inserting the two plugs of a pair into the two switches of the lines connect any line which has an answering-switch and an annunciator at her board with any line which has a calling-switch at her board, substantially as set forth.

7. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, switches for said lines, one switch for each line of one class on each board of one section and one switch for each line of the other class on each board of the other section said switches being for making connections with their lines when called for, and which may therefore be designated as calling-switches; also two switches for each line, one switch on a board of each section to make connection with its line when its subscriber calls, and which may therefore be designated as an answering-switch, signaling apparatus whereby a subscriber may at will signal to either board where one of its answering-switches is located, and pairs of switch-plugs with cords at each board,whereby the operator may by inserting the two plugs of a pair into the two switches of the lines connect any line which has an answering-switch at her board with any line which has a calling-switch at her board, substantially as set forth.

8. In a telephone exchange system, two switch boards, a telephone line connected with said boards, and two annunciators in the circuit of said line, one at each board, said annunciators being adapted to respond to currents of different character, in combination with a source of electric energy, and a calling-key at the subscribers station with contacts to send a proper current to line to operate one of said annunciators when said key is in the normal position, and contacts to send a current to line to operate the other annunciator when the key is moved or depressed.

9. I11 a telephone exchange system, two switch boards, a telephone line connected with said boards, and two polarized annunciators in the circuit of said line, one annunciator located at each board, one annunciator indicating when a current of one polarity passes through it and the other annunciator indicating when a current of the other polarity passes, in combination with a signalin g-generator at the subscriberss station, an d a calling-key with contact-points to send a current of one polarity to the line when the generator is operated and the key is depressed, and to send a current of the other polarity to line when the generator is operated and the key is not depressed, substantially as set forth.

10. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, a switch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and on a board of the first-mentioned section, each line passing successively through its switches on the different boards and thence to ground, and pairs of switch-plugs distributed among the boards, said plugs of a pair being connected by flexible conducting cords and adapted to be inserted into the switches at their board, and when a plug is inserted to disconnect the line to which the switch belongs and connect it with the conducting-cord of the plug, substantially as and for the purpose set forth.

11. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, a switch for each line of one class on each board of one section and 011 a board of the other section, and a switch for each line of the other class on each board of said other section and on a board of the first-mentioned section, two annunciators for each line, said annunciators of a line being at two boards of different sections and where the line has switches, each line passing successively through its switches on the different boards, thence through its two line-annunciators and thence to ground, and pairs of switch-plugs distributed among the boards, said plugs of a pair being connected by flexible conducting-cords and adapted to be inserted into the switches at their board, and when a plug is inserted to disconnect the line to which the switch belongs from its annunciators and the ground and connect it with the conducting-cord of the plug, substantially as set forth.

12. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, a switch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and-on a board of the first-mentioned section, two annu nciators for each line, said annunciators ot' a line being at two boards of different sections and where the line has switches, each line passing successively th rough its switches on the different boards, thence through its two line-annunciators and thence to ground, and pairs of switclrplugs distributed among the boards, said plugs of a pair being connected by flexible conducting-cords and having a clearing-out annunciator in the circuit between them, said plugs being adapted to be inserted into the line-switches at their board, and when inserted into two switches to disconnect the lines from their annunciators and the ground and connect them with the conducting-cords of the two plugs, respectively, substantially as set forth.

13. In a telephone-exchange system, the combination of telephone-lines divided into two classes, multiple switch-boards for said lines divided into two sections, a switch for each line of one class on each board of one section and on a board of the other section, and a switch for each line of the other class on each board of said other section and on a board of the first-mentioned section, switchconnecting apparatus whereby an operator at any board may connect together any two lines which have their switches at her board, and switch-testing apparatus whereby she may test any line which is connected to all the boards of her section and determine whether it is switched for use, substantially set forth.

MILO G. KELLOGG.

Witnesses:

\VALLAOE L. DEwoLF, MILTON HEAD.