US661714A - Telephone-circuit. - Google Patents

Description

Patented Nov.- [3, I900. I. H. FARNHAM &. G. W. DAVIS.

TELEPHONE CIRCUIT.

(Appiication filed -May 11, 1900.1

2 Sheets-Sheet l.

Fig. 4'.

WITNESSES:

m: NORFIS wnzns cu. Wow-vino wsumswu. 11c.

Patented Nov. [3, I900. l. H. FARNHAM'& G. W. DAVIS.

TELEPHONE CIRCUIT.

(Application filed May 11, 1900.1

2 Sheets-Sheet 2.

(No Model.)

1N VENT 13$ wbm WITNESSES W WW m: Nmws yzrins cc, PMGTO-LITHO.\VASHINGTON a. c

' NiTED STATES PATENT OFFICE.

ISAIAH H. FARNHAM, OF YVELLESLEY, AND GEORGE W. DAVIS, OF REVERE, MASSACHUSETTS, ASSIGNORS TO THE NEIV ENGLAND TELEPHONE AND TELEGRAPH COMPANY, OF BOSTON, MASSACHUSETTS.

TELEPHONE-CIRCUIT.-

SPECIFICATION forming part of Letters Patent No. 661,714, dated November 13, 1900.

Application filed May 11, 1900. Serial No. 16,306." (No model.)

To all whom it may concern:

Be it known that we, ISAIAH H. FARNHAM, residing at Wellesley, in the county of Norfolk, and GEORGE W. DAVIS, residing at Re: Vere, in the county of Suffolk, State of Massachusetts, have invented certainlmprovements in Telephone-Circuits, of which'the following is a specification.

In the operation of street and other railways it frequently becomes desirable for the conductor of a car or of a train of cars to eifecl communication with a central station in order to report thereto any trouble that may have occurred to the railway equipment or for any other reasons which require immediate help or attention.

The object of the present invention is to provide means whereby the conductor of a car may connect himself telephonic-ally with a central station, and to this end we provide a circuit whose conductors are strung upon the telegraph-poles along the route of the track, in case the invention is applied to steam-railways provided with such poles, and if the application is to an electric-car railway the conductors are carried upon the supports which carry the trolley or feed wires. These conductors are open at one end and at the other end enter the central station and are closed there through a'generator of electricity and a relay controlling a bell or signal, which circuit is adapted when it is closed at any point away from the central station to ring a bell or display a visual signal, there being an attendants or operators telephone in a normally open shunt around the generator and signal.

At suitable intervals in the circuit normally open branch terminal conductors are 40 brdhght down from each of the line conductors to switch-boxes, preferably of iron, secured to the sides of the poles. Each switch box is provided with a door or cover and with suitable spring-socket contacts for the reception of plug-connectors. The branching conductors are protected in iron pipes, which extend from the boxes ..to a proper height above the same. To enable the conductor of a car or train to communicate with the central station, we provide a transmitting and a receiving telephone and a flexible extensible plug-connector, all adapted to be inclosed and protected within a portable box or case, the telephone -transmitter being preferably secured to the back of the box, the

receiving-telephone being provided with a support, and space being made for the said connector, the box itself having a suitable handle by which the whole outfit may be readily carried about and supported upon a pole when in use. When not in use, the portable telephone set may be placed in a locker of the car.

When the conductor wishes to communicate with the central station, the portable set is carried to a pole upon which is secured a switch-box, and the handle thereof is hung over the switch-box, the door opened, and the plug-connector taken outand inserted into the spring-sockets of the switch-box and the telephone-receiver removed from its support. The insertion of the plug-connector into the said sockets closes and completes the circuit through the generator and the relay controlling the bell or signal at the central station, and thereupon the bell rings or-a signal is displayed, and when in response thereto the attendant removes the telephone from its hook-switch to answer the call the switch operates to include the central-station telephones in the line-circuit and at the same time to open the bell or signal circuit.

The invention relates to the circuits shown anddescribed and to the specific mechanical and electrical appliances used in connection therewith.

In the drawings which illustrate the invention, Figure l is a perspective view of an electric trolley-railway. Fig. 2 is a detached portion of a conductor-supporting pole, showing the location thereon of a switch-box and the suspension thereto of a portable telephone outfit. Fig. 3 is an enlarged portion of the switch-box with its door or cover removed. Fig. 4 is an enlarged view of the portable telephone outfit, showing the door open and the plug-connector removed. Fig. 5 is 21 diagram of the circuits embodied in the invention, illustrating the connection of three railway-circuits with a central station; and Figs.

6 and 7 are modifications of the switch-box.

Referring to the drawings, a a represent the conductor-so pporting poles of an electric trol Icy-railway. t

Z) b are projecting-arms sustaining the trolley-wire c.

d d are cross-arms having on each end insulators e e, to which are attached the conductors ff which constitute the circuit F,

extending to the central station L. At, suitable intervals branch conductors g g extend from the respective conductors ff and pass down a protecting-pipe h, whose upper end is covered by any suitable cap 41.

lower side of the box A. The block tis fas- The tened to the box A by the screws to u. holes inthe floor of the box are made larger in diameter than those in the blocku to prevent electrical contact with the connectingplugs.

13 represents the box which contains the portable telephone outfit, provided with the door D on the front side, hinged to the box and adapted to be secured when closed by the v hasp and button 8 and 9, and Z0 is a handle, preferably Hat and flexible, secured at each end to the opposite sides of the box. Within the box and to its back is secured a telephonetransmitter M, and the telephone-receiver T is adapted to be supported therein upon the cleats 5 and 6, and its terminals are connected by the flexible cord P to the screw-posts 3 and 4. p

C is a double plug-connector consisting of an insulating-handle in which are inserted the metal plugs or terminals 12 and w of different diameters, which are connected to the insulated conductors g and 9 which constitute the flexible cord E and are joined to the opposite poles-of the battery H, the electro-,

magnet of the signal-controlling relay I being shown in circuit with the latter conductor. A

Wire 14 connects the conductor f with the.

foot of the relay-armature 12, whose free end is opposite a terminal 13 of the bell J, whose opposite side is connected by wire 11 with the resting-contact 21 of the hook-switch 10, and

The lowerend of the pipe is screwed into the upper side of wire f connects the point 20 with the hookswitch. The telephones are in series with one another by means of the wire 8, which connects one side of the receiver T with point 7 on conductor f It Will be readily understood that an annunciator or other visual signal may be substituted for the bell.

The operation of the invention is quite apparent from what has been said; but a brief description will perhaps be required When for any cause the conductor of a car wishes to communicate with the central station, the box B is suspended from the switch-box A by passing its strap handle over the latter, as shown in Fig. 2, the plug-connector C removed from t-hebox, and its terminals inserted into the switch-sockets-the plug '0 into the hole 'v and the plug 20 into the hole w-and as the connector is pressed in the springs s and 8 are forced against the respective springterminals 19 and p so that the circuit is continued from the branches 9, spring-terminals p, springs s, to the respective jplugs, as will be easily understood. The springs s s by their bent ends furnish a protection to the circuit springs, and if any foreign plug or wire is mischievously inserted no connection is made with the connectors 13, and a further protection is. provided in making the plugs and their sockets of different diameters, and

the battery-current is thus always passed through the receiverin the same direction, preventing the demagnetizing of the receivermagnet. When the plug-connector O is thus inserted, the circuit is closed thereby through the central-station battery H, the relay I operates in a well-known manner, and the bell rings or a visual signal is displayed. When the telephone T is removed, the switch 10 in rising closes with contact 9 and opens the signal-circuit and includes the telephones in the shunt-circuit. Current from battery H then circulates throughout the circuit F, and when the transmitters are used the current is varied in a well-known manner.

One op'erators telephone set may be made available fora plurality of railway routes, as indicated in Fig. 5, and there will be no disturbance should a call bereceived from a box on a second route while conversation is taking place between a boxon any route and the central station, as the operator can easily take care of both. v

Fig. 6 represents a modification of the switch-box, in which the branches 9 and g are connected to spring-terminals s and 8 secured to the insulating-block M, and C is a single plug provided with two contact-surfaces 0 and 7113, which register with the springs s and 8 respectively. The plug 0 is adapted to be passed through a hole in the floor of the box large enough to prevent the plug from coming into contact with its sides. Fig. 7 is another modification of the switchbox, in which'a double plug is used. In this case the door is hinged to the case and is locked thereto when closed, and to insert the plug the door is opened. There are some advantages in this construction, as no apertures are made in the walls of the box.

It is within the spirit of our invention to use a portable transmitter and receiver, both of which are secured to a common bar or support of a well-known construction, and the instruments will be connected by a flexible cord with the plug-connector.

We claim as our invention- 1. A telephonic circuit composed of two conductors open at one end and provided with a series of branches extending from the conductors to normally open terminal switches inclosed in a series of boxes; the other end of said circuit being closed through an electric generator; a branch from one of said conductors including telephones normally open at the hook-switch; a signal-circuit controller having its windings in one of said conductors, a signal adapted to be operated by said controller and to be included in parallel with said generator, and adapted to be inoperative by the said hook-switch; with a portable telephonic outfit or set, inclosed in a box, consisting of a telephone-transmitter, a receiver, and a plug-connector, united in series by con ducting-wires, as set forth.

2. A telephonic circuit composed of two conductors open at one end and provided with a series of branch extensions from the conductors to normally open terminal switches inclosed in a series of boxes; the other end of the circuit being closed through an electric generator; a branch from one of the conductors includingtransmitting and receiving telephones normally open at the hook-switch; a signal-circuit controller having its windings in one of the conductors, asignal in a circuit parallel with the generator open at the controller and normally closed by the hookswitch; with a portable telephonic set inclosed in a box consisting of a telephonetransmitter, a receiver and a double plug-con nector united in series by conducting-wires, as set forth.

3. A system of telephonic intercom m unication composed of a plurality of metallic circuits each comprising two conductors open at their outer ends and provided with a series of branch extensions from their conductors to normally open terminal switches inclosed in a series of boxes; the inner ends of the circuit-conductors being combined and closed through an electric generator at a central station; a branch from one side of the combined circuit including transmitting and receiving telephones normally open at the hook-switch; a signal-circuit controller having its windings in one side of the combined circuit, a signal in a circuit parallel with the generator open at the controller and normally closed by the hook-switch; with a portable set or sets, inclosed in a box consisting of a telephonetransmitter, a receiver and a plug-connector, united in series by conducting-wires, as set forth.

4. A system of telephonic intercommunication comprised of a metallic circuit open at one end and closed through a battery and the windings of a signalcircuit-controlling relay at a central station; a signal device in a derived circuit around said battery normally open at said relay and normally closed at and by the telephone-hook switch; transmitting and receiving telephones in a normally open derived circuit around said battery; the circuit-conductors being secured to a series of poles; a series of branches extending from the conductors to normally open terminal switches inclosed in a series of boxes secured to said poles; with a portable telephonic outfit or set inclosed in a box consisting of a fixed telephone-transmitter, a movable telephonereceiver and a plug-connector, united in series by connecting-wires, as set forth.

5. A switch-box for the purpose set forth, adapted to be secured to a suitable support, consisting of a metal casing provided with a detachably-secured door or side; a block of insulation secured to a wall of the box supporting two spring-terminals, and two springconnectors wit-h bent ends; a second block of insulation secured to a wall of the box having holes opposite the said spring-connectors and coinciding with holes in the wall of the box; with a tube extending upward from the box to the top of which is secured a protectingcap, as set forth.

In testimony whereof we have signed our names to this specification, in the presence of two subscribing witnesses,this 8th day of May, 1900.

ISAIAH H. FARNHAM.

GEORGE W. DAVIS. Witnesses:

WILLIAM S. WILDER, GEORGE S. MOYNAHAN.

Images