US251178A - Telephone switch device - Google Patents

Description

(No Model.)

C. E. BUELL.

TELEPHONE SWITCH DEVICE.

Patented Deo. 20,1881.

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WI'I NESSES' UNITED STATES PATENT EEicE.

CHARLES E. BUELL, OF NEW HAVEN, CONNECTICUT, ASSIGNOR OF TVO- THIRDS TO JAMESv G. SMITH,

OF HACKENSACK, NEV JERSEY, AND

GEORGE W. CCY, OF MILFORD, CONNECTICUT.

TELEPHONE SWITCH DEVIC.

SPECIFICATION forming part of Letters Patent No. 251,178, dated December 20, 1881,

Application filed September 24, 1881. (No model.)

T 1 all whom it may concern Be it known that I, CHARLES E. BUELL, a citizen of the United States, residing at New Haven, in the county of New Haven and State 5 of Connecticut, have invented certain new and useful Improvements iu Telephone Switch De- \'ices,of which the following is a specification.

In an application for patent filed by me March 22, 1881, N o. 29,4538, of which this presentapplication is a division, I have described an invention the object of which is to simplify the construction and arrangement of apparatus at subscribers stations of telephone-lines and to do away with the use of local batteries.

In carrying out that invention I have proposed to arrange ateach subscribers station van induction-coil whose primary coil may be connected to the line-circuit, to connect the receiving-telephone at each station in a local circuit ith the secondary of said induction` coil, and for purposes of oral communication to place the contact transmitters directly in the line-circuit, which is itself to be charged during oral communication,between two points by a battery or generator at the central office, or at either or both of' said points. proposed to place at each station of a line arranged as above described a switch device electrically controlled from the central office, and provided with a spring or equivalent locking device controlled by the weight of' the telephone, the whole so arranged that when the line is not in use at anystation the removal of the telephone will automatically lock the transmitter and the primary ot' the ind uction-coil in circuit, while it' the telephone is removed from its hook when the line is in use at other sta-- tions and properly charged by a battery at the central office the switch will be locked in position so that the circuit through the transmitter and induction-coil will be held broken, and the branch circuit completed by the movement of the switch when charged by the battery at the central office will be held closed.

My present application relates to the switch device last referred to, and also to the centraloffice switch apparatus employed in connection therewith and with telephone-lines whose subscribers7 stations are provided with induction- 5o coils and telephone-instruments connected to I have also line and to one another according to the invention which forms applica-tion.

Figure l is a diagram illustrating one plan ot' arranging telephone apparatus according 55 to the invention which forms the subject ot' my application before referred to. Fig. 2 shows the manner of applying the automatic switch which forms the subject of the present application, and shows also the central-office 6o apparatus to be used with said switch or with a telephone system in which the subscribers station apparatus is constructed iu the manner indicated in Fig. l.

In Fig. 1 the apparatus at each thus arranged:

A is a gravity-switch connected to line on that side ot' the station nearest the central ot'- ice, and making contact, when depressed by the weight ofthe magneto-telephone t, with a 7o contact-stop, 1, joined through a circuit-breaking or signaling key, k, and a signal-bell, S, with the line on the other side of the station. The magneto-telephone t is connected in local circuit with the secondary of an inductioncoil, I.

M indicates a battery or contact transmitter of any approved constructioli,whose electrodes are directly in a circuit passing from the contact-stop 2 of the switch through the primary 8o of the induction-coil to the point a, where connect ion is made with the line. When the switch is relieved from the weight of the telephone, contact is made with the point 2, and the mainline circuit is then directly through the battery-transmitter and the primary of the induction-coil, while at the same time the circuit through the signal-bell S and the key K is broken.

C designates a central station, and D a 9o charging-battery located thereat, which is connected to line when oral communication takes place between any two of' the stations represented.

Bell S and key K are for use in the ordinary manner in conjunction with the usual apparatus employed at the central station.

For the purposes of oral communication b'etween any two stations the switches at those stations are so manipulatedk as to place the Ico transmitter M and primary of induction-coil I direct-1y in the main line, and the battery D at the subject of my prior station is 65 the central ofce is connected to the line. Under these circumstances it is obvious that either transmitter, when spoken to, will vary in the well-known manner the current of battery D passing through the primaries ot'I, and the result will be a succession ot'secondary pulsations iu the telephonesT in a manner to produce articulate sounds.

I do not design limiting` myself to any particulararrangementor construction oi switches and devices, as there are many well known in the art, and I contempla-te the employment ot' others besides those here described. It is evident that the charging-battery may be placed at either of the points that are telephonically connected.

In Fig. 2 I have shown a modified arrangement of devices at the subscribers station forming the subject of this application. In this plan I employ a provision for cuttingr the transmitter and primary of the induction-coil out of the circuit when the line is in use at another station, or stations. I have also means whereby, when the line is not in use and the receiving-telephone at any station is removed from its support, the transmitter and telephone at that station are locked in circuit and the operation of an electro-magnetic switch controlled by the central ot'lice can be only made effectual to cut out the transmitter and induction-coil of other stations. For this purpose I make use at the subscribers station of an electro-inagnetic switch adjusted above a normal weak current and provided with contacts and ccnneetions so arranged that when against its back stop the main-line circuit will be through the transmitter and induction-coil, but when operated by a current of suiicient strength it will break said first circuit and complete a branch circuit around the transmitter and induction-coil. For the purpose of signaling to the central station without affecting said.

switch, I may decrease still further the tension ofthe normal line-current, or may entirely break it.

G designates a case, to the cover of which is secured a contact or battery transmitter, whose diaphragm isindicated at H and electrodes atE.

I? is an arm supporting the movable or adjustable electrode. The automatic switch is controlled by the electro-magnet of the callbell, and consists of the armature lever and bell-hammer, connected directly through electromagnet E M with the line-wire on the side leading to the central station, and provided with contact-stops 5 and 6, one connected to the line-wire on the other side of the station and the other with the primary of the induction-coil I, the hinges ot' the box, the circuitbreaking call-key k, (shown in bottom view,) the diaphragm of the transmitter and electrode in contact therewith, and to the line-wire L. The secondary of the induction-coil I is connected to the receiving-telephone T,bypref erence permanently.

The telephone-support R consists of a bladespring, or ofany suitable spring-actuated support. It is provided with a locking-point, 7, of suitable shape, which engages with the switch lever, when it is relieved from the weight ot' the telephone, upon the one side or the other thereof, according as said switch-lever is drawn forward by the electro-magnet or is against its back stop, and, according to the condition ofthe switch, locks the transmitter and induction-coil into or out of circuit. With a normal or weak current to line, which is designed to be broken or weakened by signaling-key K, and tothereby affect delicatelyadjusted apparatus at the central station, the switch-lever is in the position shown in full lines, the strength ofcurrent being insufficient to draw it forward against the stress ot' itsretractile spring T, as adjusted. The path ot the main-line current at this and other stations upon the same line is then through electro magnet E M, switch-lever 3, back stop, 5, induction-coil I, key K, and transmitter contacts. By stillfurther weakening the normal current, or by breaking the circuit by key K, or in any other suitable manner, a call may be sent to the central office. The removal of the telephone T from its support will allow the same to rise, and the locking-point upon the end thereof will come into position to lock the lever in the condition shown in full lines, with the circuit through the transmitter. For the purpose of cutting out the transmitter and induction-coil at other stations, an increased battery is used during oral communication, which draws the switch-lever forward and holds it in that position while the line is in use. At all stations where the telephone is still attached to its support the lever will be free to move to break the circuit through the transmitter and the induction-coil, and it will be held in the position shown in dotted lines so long as the stronger or increased battery is to line. Under these circumstances the locking-point 7, when a telephone at any of such stations is removed from the support, willcome into position to lock the armature against stop 6, in which position the circuit through 5 is broken.

The subscribers station may be called in the well-known manner by placing to line a current of suiicient strength to overcome the stress of retractile spring T. Other specific devices may be used in place ol" those herein described, as the principle of the invention consists in causing the support for the telephone, when relieved of its presence, to lock an electro-magnetic switch controlled from the central office in position to hold the circuit through the transmitter or the receiving devices closed, so that when the switches are operated to hold the transmitters or the receivers at other stations out ot' circuit the switch at the station whose telephone is in use cannot be aiected.

Other arrangements ot' circuits and devices willreadily suggest themselves to those skilled IOO IIO

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-in the art, whereby the combined switch and -ized for this purpose.

It is obvious that such an arrangement of switch and lock might be adopted with the systems in ordinary use in which the line is charged normally; but the battery is withdrawn from the line-circuit when the telephones are in use. In such a case,however, the switch would be arranged to complete the circuits controlling the operation otl the communicating apparatus when drawn forward bythe electromagnet, and to break such circuits or close a shunt thereto when against its back stop. In otherrespectsits operation,iu conjunction with the lock-support for the telephone, would be the same.

A central-ndice switch and one plan ot devvices for completing the necessary connections through the charging-battery usedduring oral communication between subscribers on the same ordift`erentlines,or between a subscriber and the central ofce, is shown at C O. .For the sake of simplicity but four lines are shown, each of which is connected to a vertical or line strip, S, in turn connected, when the lineisnot in use, through switch-levers h, with a battery, M B. This battery is of sufficient strength to chargethe electro-magnets of the annunciators and bells at the central office, but is not sui-ticient to operate the switch and bell electromagnets at the subscribers stations.

The charging-battery to be used dui ing oral communication is shown at D B, one pole joined to a connecting strip or wire, n, and the other to a similar connecting-strip, m, throughacircuit-breakingkey,K,andaswitch, 12, which serves to make the connection directly through 13 or indirectly throughthe primary ot induction-coil I, electrodes of transmitter M, and poiut14. The secondary of the` induction-coil is connected7 asin the other iigures, to the receivingtelephone T. The connectingstrips or wires are provide-d with switches 17 and 19, which may be thrown into contact with the line-strips. The terminal switches 1S may be placed in contact with a plate or strip, 20, connected to ground.

K K designate calling-keys, which may control a separate battery, K B, for the purpose ot' signaling to a subscribers station after the manner describedin patent to Geo. W. Coy, tiled February 17,1880, No. 224,653. I propose, however, to use for this in ordinary cases the charging-battery D B. The annuneiators 1234 arearranged and adjusted to give a signal upon a weakening or breaking ot' the line-current from battery M B. When the noninterference switches are used it is necessary that the charging-battery DB used during oral communication should be stronger than the normal line-battery M B, for the purposes before explained. W'hen, however, the arrangement shown in Figl is employed the relative strength of said batteries is immaterial, and the main or signaling batteries or sections 'thereof may be under some circumstances'the charging-battery. The strip 20 should, by pret'- erence, be normally connected to one ot'the connecting-strips-say ll-by a terminal switchlever, 18. Upon the reception ota signal from any line its vertical strip is connected with battery D B by a switch lever, i8 or 19, a-nd its switeh-leverh is disconnected. The charging-battery D B is thus thrown to line, the circuit being from ground to bar 20, lever 18, connecting-strip m, switch-point 1 2, transmitter M, induction-coil I, key-batteryvl) B, strip n, switch-lever 18 or 19, andl line-strip, to line. Conversation may then bel carried on between the subscriber and theI central station through their battery-transmitters, which are iu the direct circuit ofthe charging -battery and the primaries ofthe induction coils whose secondaries include the receiving-telephone. It'the lock-switches are used at the subscribers station, the result of connecting the battery D B to that particular line has been to cut out the transmitting and receiving apparatus at all stations upon said line excepting at the station calling. Should the call be for a station upon thcsame line, the signal appropriate to that station maybe given by manipulatingthe circuitbreaking key.v The charging battery is then to be withdrawn from line for an instant to allow the subscriber called to lock his telephone in circuit, and alter that has been done the battery is to be again placed to line, thus cutting out the apparatus atall other stations and placing the line in condition for oral communication. It' desired, the weaker battery M B may be placed to line when the stronger batteryis disconnected. andthe subscriber called may then give notice of the t'act that he has removed his rcceivingtelephone from its support, so as to lock the switch, by operating his calling-key. When this signal is received at the central office the battery D B is again introduced and the connection to battery M B broken. It' the subscriber with whom communication is desired is upon another line, the connection ofthe plate 2l) withstrip m is to be broken,and the lines may then be connected through the linestrips and the charging-battery by throwing the proper lineswitches 17 and 18 or 19. In the diagram lines l and 4 are shown thus connected. Thepath ot the current may be readily traced. When the arrangement ot' switches shown in Fig. 1 is used the operation of the central-office switch is substantially the same as alreadydescribed. Under such circumstances, however, subscribers may be called in the ordinary manner by circuit-breaking keys introduced in the several lines at the central office.

It is obvious that other switch mechanism may be used for the purpose of making the desired connections and for introducing the charging-battery, and in practice the manipulation would be much simplified.

The central-ottice switch is shown in the form indicated to avoid confusion.

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As many pairs of connecting-strips m aand as many charging-batteries D B are to be used as may be required by the size ot' the exchange and the frequency ot' the connections.

Instead ot' the switches 71, and 19 for each line, a single switch may be used, its pivot connected to the line-strips, and its free end arranged to make connection with either of two studs, one connected to battery M B and the other to strip u.

It' desired, an independent electro-magnet may be used instead ot' the bell electro-magnet for controlling the station-switch.

Instead of using a neutral electro-m agnet for the switch, I may employ a polarized electromagnet, and control the same by changing the polarity when the line is charged for oral communication.

I do not in this application make any claim to the arrangement of the primary coil and charging-battery in the main-line circuit and 'thesecondary coil and receiver in the local circuit; nor do I malte any claim to the plan of arranging the primary1 in one loop or branch and the bell in the other loop or branch, as shown in Fig. l, as these form the subject of my prior application.

l/Vhat I claim as my invention is l. In a telephone-station apparatus, a contact-transmitter normally in the main-line circuit, in combination with an electro-magnetic switch whose back contact is included in the circuit of said transmitter and whose front Acontact completes a branch circuit around the same, substantially as described.

2. rIhe combination ot' an electro-magnetic switch in the main-line circuit, connections through the transmitting or receiving apparatus controlled thereby, and a locking device released by the telephone for the purpose of locking said switch in position where the circuit through the telephone apparatus will be closed.

3. In combination with an electro-magnetic switch-levercontrolling the circuit-connections through a telephone, a spring telephone-support arranged, when freed from the weight of the telephone, tolock the switch-lever upon one side or other thereof, according as said lever is against its front or its back stop.

et. An electro-'magnetic switch controlling the circuits through the instruments at a telephone-station, and located in the direct circuit at said station, in combination with mechanical locking devices brought into connection with said switch in the act of using the instruments, substantially as and tor the purpose described.

5. In a telephone-exchange system, two or morelines normally connectingtoearththrough a battery, and devices for connecting any two lines together through a battery of increased power, substantially as and for the purpose described.

6. In a telephone-exchange switch,one or more pairs of line-connecting strips, each of which is connected to one pole of agenerator, and each providedY with switch devices for connecting one ot' said strips to earth, substantially as and for the purpose described.

7. In a telephone-exchange switch, line-connecting strips and circuit-connections tht ret'rom passing through a galvanic battery and contact-points of a battery-transmitter, as and 'or 4the purpose described.

8. At each of a series of stations on a telephone-line, electro-magnetic switches whose y retractile devices are adjusted above the strength of current normally connected to said line, and which control through suitable connections the circuits ot telephone-instrnments, in combination with devices at a central station for increasing the strength ot' current for the purpose of operating said switches.

9. An electro-magnetic switch at a station of a telephone-line, provided with contacts and connections whereby the telephone may be thrown into and out of operative electrical condition byincreasngand decreasingthestrength of current upon the line, substantially as described, in combination with a bell and a bellhammer attached to the vibrating portion ot' the switch.

l0. The combination of two or more telephone-lines, each ot' which contains devices at the subscribers7 stations for introducing the primary of an induction-coil and a-batterytransmltter into the line-circuit, a central-ot'- ce switch to which said lines are connected, and switch devices for connecting any two lines through a battery for oral communication, substantially as described.

CHARLES E. BUELL. Witnesses:

.GEORGE W. Cov, THOMAS TooMEY.

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