US1387251A - Telephone system - Google Patents

Description

C. B. FOWLER.

TELEPHONE SYSTEM.

APPLICATION FILED DEC. 16, 1919.

Patented Aug. 9, 1921.

hvenfor: C/a/"e/vce 15, Pow/er UNITED STATES PATENT OFFICE.

CLARENCE B. FOWLER, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COM- PANY, INCOBPORATED, OE NEW YORK,

N. Y., A CORPORATION on NEW YORK.

' TELEPHONE SYSTEM.

Specification of Letters Patent. Patented Aug, 9, 1921.

Application Tiled December 16, 1919. Serial No. 345,311. 5

To all whom it may concern Be it known that I, CLARENCE B. FOWLER, a citizen of the United States, residing at New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is a i'ull, clear, concise, andexact description. p

This invention relates to telephone systems and has for its object the production of improved signaling means for such systems. V

In the present embodiment of this invention means, individual to a subscribers line, are provided at a central office whereby after restoring his receiver to the switchhook a calling subscriber may, by removing his receiver from the. switchhook before the disconnection of the cord circuit from his line, operate a distinctive signal to recall the operator. The operator on noticing the recall signal may idiscontinue its operation by touching the sleeve contact of the answering plug or ack with the tip of the plug of any cord circuit, as in making a busy test,

and may then dep'ress her listening keyto connect her head-setwith the line.

Byprovidingapparatus individual to the subscribers lines for furnishing a distinctive recall signal, it is unnecessary to install special cord circuits when thisfeature is desired by lines terminating in an exchange provided with cord circuits not arranged for such recall signals. I Y

Figure 1 of the accompanying drawing is a diagrammatic representation of thatpon tion of a telephone system 'necessaryto an understanding of theinvention. There is shown a subscribers line 1, which terminates at a central oflice in an'answering jack 2, and in multiple jacks 3, of which but one is shown. An answering plug 4c of one cord circuit is shown, but any number of cord circuits may be used. The relays and line.

lamp shown are individual to the line, and the supervisory lamp to the cord circuit,but the battery and interrupter may be common to several cords and lines. Fig. 2 of the drawing shows diagrammatically the method of discontinuing the recall signal by touching with the tip of an idle plug, the sleeve contact of the plug of a connected cord circuit. It is believed that the invention will be readily understood from a consideration ofthe operation of the system, which is asfollows:

A subscriberdesiring toinitiate a call removes his receiver from its hook, thereby completing an energizing circuit for line relay 5 which may be traced from grounded battery through the right hand winding of relay 5 ,-back contact and inner armature of cut-01f relay 6, and thence through the subscribers line loop, outer armature and back contact of relay 6, through'the left hand winding of relay 5 to ground. Relay 5 in energizing completes a circuit from grounded battery through lamp 7 contact and innermost armature of relayb, back contact and inner armature ofsleeve relay '8, to ground. Line lamp 7 is lighted in grounded battery through lamp 9, sleeve contacts of plug 4., and jackQ, through the right hand low resistance winding of sleeve relay 8 and the left hand high resistance winding of this relay to. ground. Relay 8 is energized in this circuit, butis of such high resistance that lamp 9 does not light.

In attracting its inner armature relayy8.

interrupts, the circuit of line lamp 7, to extinguish this lamp. In attracting its outer armature relay 8; connects battery through resistance 11, to the sleeve contacts of the 4 in jack 2, a circuit is completed from multiple jacks of the calling line in order to furnish a busy test.

At the completion of the conversation when the calling subscriber replaces his re-- ceiver on its switchhook he interrupts the previously traced circuit for line relay 5 and this relay becomes inert. A circuit is thereupon completed from grounded battery through the winding of relay 12, back contact and outermost armature of relay 5,

front contact and inner armature of relay 8 to ground. Relay 12 in attracting'its left hand armature completes a locking circuit.

for itself independent of the contact of relay 5, and in attracting its right hand armature completes a circuit from ground,

back contact and middle armature of relay 5, right hand armature and front contact of relay 12, through the right hand winding of relay 8, sleeve contacts of jack 2 and plug 4, through supervisory lamp 9 to grounded battery. The high resistance winding of relay 8 is shunted by this circuit to light supervisory lamp 9 to furnish a disconnect signal, but relay 8 is held energized.

Should thesubscriber desireto recall the operator,aft er having replaced his receiver on its swit'chhook, he removes it therefrom and again completes the circuit for the line relay; Relay 5 in attracting its middle armature includes interrupter 13 in thepre .viously traced circuit for the supervisory grounded, serially connected windings'of relay 8, thus shunting these windings; Relay 8 in deenergizing opens the locking circuit for relay 12, which deenergizes to open the circuit for the supervisory lamp 9, thus extinguishing this lamp. Upon removing the plug with which she has touched the sleeve of plug 4: the operator breaks the shunt circuit for relay 8 and this relay is again energized through both windings in series with the line lamp and the'relays are" in the condition in which they normally should be during the progress of a call.

When line 1 is called, battery is connected through the sleeve of the calling plug (not shown) and the sleeve of multiple jack 3, through the outer armature and back contact of relay 8 and the winding of cut-01f relay 6 to ground. Relay 6 is eninserted into ergized in this circuit to cut ofi' line relay 5 which supplies talking current to line 1 when it is a calling line, talking current now being supplied through the calling end of the connected cord circuit.

What is claimed is:

1. In a telephone system the combination with a telephone line, a cord circuit for extending said line, a signaling device individual to said cord circuit, and means individual to said telephone line responsive to an interruption of said linefor operating said signaling device in one manner to give a disconnect signal, said-means being responsive to a subsequent'closure of said line to operate said signaling device in a differentman'ner to give a recall signal.

2. In a telephone system the combination with a telephone line, a "cord circuit for extending said line, a signaling device associated with said cordcirc'uit, a set of relays individual to said line operated in response to the closure of said line'a-iid the connection of said cord cir'cuitto said line to prepare an operating circuit for said signaling device, a relay operated in response to the interruption of said line for completing said operating circuit, and'an interrupter included in said operating circuit, in responseto a subsequent closure of said line to operate said signaling device inter-J mittently.

3. In a telephone system the combination with a telephone line terminating in aspring jack, a number of'cord circuits for. association therewith, signaling devices associated therewith, a line relay responsive to the closure of said telephone line, a second relay individual to said; line operated. in response to the" deenergization of said line relay to complete an operating circuit for one of said'si'gnal-ihg devices, and means for causing the release of said second relay by making electrical connection between a'contact of an idle plug, and a contact of'a plug the spring jack of said line circuit; p i

In witness whereof, I hereunto subscribe my name this Gth'day of December, A. D.

CLARENCE B} FOWLER;

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