US669707A - Telephone-exchange system. - Google Patents

Description

No. 669,707. I Patented Mar. I2, I901.

C. E. SCRIBNER.

TELEPHONE EXCHANGE SYSTEM.

(Application flied Nov. 12, ,1894.)

(lo Muriel.)

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF SAME PLACE.

TELEPHONE-EXCHANGE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 669,707, dated March 12, 1901.

Application filed November 12, 1894. Serial No. 528.526. (No model.)

To all whom it may con/06 nectionis made by means of the plugs is com- Be it known that I, CHARLES E. SORIBNER, plete at the substation the clearing-out ana a citizen of the United States, residing at Chinunciator will display its signal.

cago, in the county of Cook and State of Illi- In this system the annunciator of a line is nois, have invented a certain new and useful retained in position to conceal its indicator as Improvement in Telephone-Exchange Syslong as the telephonic apparatus at the subtems, (Case No. 361,) of which the following station is not in use, the circuit of the signalis a full, clear, concise, and exact description, ing-battery through the line-annunciator bereference being had to the accompanying ing then continuous. When the telephone 1o drawings, forming a part of this specificais brought into use, the signaling-current is tion. automatically interrupted at the substation,

My invention relates to signaling appliwhereby the line magnet of the line-annunances for telephone-exchange systems; and ciator is deprived of current and permits the it consists in improved apparatus for autoannunciator-signal to be displayed. Connec- 15 matically transmitting signals for connection tion is then made with the line by means of .and disconnection between substations and plugs in the usual way. The restoring-magthe central station or exchange. net of the annunciator is thereby excited and The system of my invention comprises a again conceals the indicator or target of the source of signaling-current located at the exannunciator, while at the same time the clear- 20 change; a group of line-wires connected in ing-out annunciator becomes connected in a common with the signaling-battery, each inbranch of the line-circuit. When the conneccluding a signaling-annunciator, the circuit tion is completed with the line called forthe of the signaling-battery through the line-Wire answering-line the local circuit through and annunciator being normally closed at the restoring-magnet of the corresponding 25 each substation; means for opening the cirline-annunciator is closed, so that the operacuit while the telephone at the substation is tion of the line-annunciator of the answerin use; a clearing-out annunciator adapted ing-line when the telephone is brought into to be connected with two united lines and use to answer is prevented. Upon the comconstructed to give a signal in response to pletion of conversation and the replacement 8o 0 the completion of the circuit at the substaof the telephones upon their switch-hooks at tion, and a device for preventing the operathe substations the signaling-circuit is again tion of the line-annunciator While a line is in closed. The clearing-out annunciator in a use. The line-annunciator which I employ branch between the line and the signalingand which, together with the circuits approbattery is thus excited and displays its sig- 5 priate to it, constitutesafeature of my invennal, which is interpreted as a signal for distion, comprises an indicator, a line-magnet connection. arranged to conceal the indicator when it is My invention isillustrated in the accompaexcited, and an auxiliary restoring-magnet nying drawings. adapted to cause the indicator to be concealed Figure 1 of the drawings is a diagram repo 40 independently of the action of the line-magresenting the general organization of the sysnet. The line-magnet of this annunciator is term as applied to a multiple s itchboard of included in the corresponding line-circuit, twosections,twosubstations beingshownconand the auxiliary magnet, which I will designected with the exchange. Fig. 2 is a side nate the restoring-magnet, is included in elevation of the line-annunciator. Fig. Sis a 5 4; a normally open local circuit which is autosimilar elevation of the clearing-out annunmatically closed at any spring-jack in the act ciator which I employ.

of inserting a plug therein to connect with The apparatus at thesubstation-forexamthe line. The clearing-out annunciator is inplc, at substation A-comprises a telephone 1) cluded in a branch of the signaling-battery and transmitter-b and a signal-bellb iu sepa- 50 tothe conductor of the plug-circuit, so that rate branches from the line, an automatic while the circuit of the line with which contelephone switch-hook I) being provided to ple switchboard, and includes the line-coil eof an annunciatorfupon the section d. The line after passing through the annunciatorcoil is grounded through a battery g, which is common to all lines of the exchange. Each spring-jack comprises three contact-pieces-- a thimble h and two normally separated springs h and h The thimble h is connected with the line conductor of the line, the spring -h' is grounded, and the spring b is connected,

through the restoring-coil e of annunciator)", with the terminal of battery 9.

The construction of annunciatorfis shown in Fig. 2. It comprises a core upon which are wound two helices e and e, a shutter 6 which serves as an armature for the core, and a light shield or indicator 6 which is adapted to be acted upon by the shutter e The shutter e is pivoted at its lower edge and a little to one side of its center of gravity on trunnions e in i a bracket 6 forming part of the frame of the instrument. Before the shutter is hung the shield e being pivoted at its upper edge in an extension of the bracket. The shutter 6 carries a projection which is adapted to engage the shield 6 near its pivotal point as the shutter falls outward and to throw the shield into a nearly horizontal position, whereby the face of the shutter e is displayed. The shutter may bear any suitable number or other target upon its face.

As long as current exists in either helix 6 or e of the magnet the core is magnetized and attracts the shutter to it, permitting the shield e to hang freely. When both magnets are unexcited, the shutter falls forward and throws the shield into its horizontal position, as described.

The operators appliances for switching lines into connection with each other and for performing the various operations involved in this are of the usual character. The connec'ting-plugs, however, are adapted for use in the particular form of spring-jack here employed. Each plug, as 't', comprises an insulated tip 2" and a shank 2' The tip is adapted to cross together the springs h if, while the shank makes connection with the thimble h. The shanks of the plugs t' and i which constitute a pair, are connected together by a conductor 2, which includes the switch-contacts of a pair of calling-keys it and it, either of which when depressed is adapted to disconnect the corresponding plug from the other plug and. to connect it with the terminal of a generator Z of signaling-current adapted to operate the signal-bell b An operators telephone set an is connected with the anvil of a listening-key n, by which the operator may bring her telephone into connection with conductor 2 of the plug-circuit.

In a branch from conductor 2 of the plugcircuit, extending to the terminal of battery 9, is included the clearing-out annunciator 0. This annunciator is represented in Fig. 3. It

comprises an electromagnet p, a pivoted armature or'shutter p, and a shield 19 The shutter 19 is pivoted at its lower edge, so as to fall outward when unattracted. The shield 19 hangs in front of shutter 17', being pivoted near its upper edge. It carries a short projection beyond its pivotal point, engaging with a hook upon the shutterp'. When the shutter, being unattracted, falls outward, shield 10 hangs freely inits vertical position; but when the shutter is attracted the hook engages the projection of the shield and cealed. When the telephone is removed f romthe hook, as shown in the drawings, the flow of the battery-current is interrupted by condenser b Magnet 6 is t-husdev italized, shuttere falls outward, and shield e is raised and gives the signal of the annunciator. The attendant at section d, where annunciatorf is located, seeing this signal, inserts plug 2' in to the corresponding spring-jack c, at the'same time depressing her listening-key n to connect her telephone with the circuit. Circuit from substation A is thus continued through the operators telephone appliances m and she is placed in communication with the call-initiating subscriber. At the same time springs 71. 72, are crossed together, whereby the local circuit of magnet e is closed and the magnet, thus excited, retracts armaturee and efiaces the signal. The annunciator o is now con nected with the line through the medium of plug-circuit 2; but since the line-circuit is open at station A the annunciator does not display its indication. The operator having tested line to station A and found it free inserts plug i into spring-jack c of that line.

The local circuit through the restoring-magnet of annunciatorf of that line is now closed. The operator signals the subscriber at station A by depressing calling-key k, and. the subscriber, having responded, removes the telephone from the switch-hook 19 The circuit from battery g through magnet e to earth at the substation is thus interrupted, but since the magnet e is still excited the annunciator is not operated. When the subscribers have finished their conversation, either may replace his telephone 17 upon the switch-hook. The circuit from conductor 2 of the plug-circuit to earth at that substation is thereby completed. Current from battery g flows through the magnet of clearing-out annunciator oand operates it, thereby instantly displaying the signal for disconnect-ion. When the operator has removed the plugs from the spring-jacks, all the circuits are returned to their normal condition.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. In combination, an indicator adapted when released to display a signal, two electromagnets adapted to act independently upon said indicator to prevent its display, a normally-closed circuit containing one of said electromagnets and means for interrupting the said circuit, and a normally-open circuit containing the otherelectroinagnet and means for closing the same circuit, substantially as described.

2. In combination in an annunciator,a shutter adapted to fall to give a signal, two electromagnets acting independently upon the shut ter to prevent its fall, a normally-closed telephone-circuit including one of said magnets and means for interrupting the said circuit, and a normally-open local circuit containing the other magnet and means for closing said circuit, substantially as described.

3. The combination with a telephone-line,

means for producing current in the line, and

a switch adapted to interrupt the current during the use of the telephone, of an annunciator and a target controlled thereby adapted to be displayed when the annunciator-magnet is inert,an auxiliary winding on the said magnet, a local circuit therethrough, and means for closing the local circuit in making connection. with the line, a clearing-out annunciator adapted to display a signal when excited, and means for bringing the clearingout annunciator into connection with the line,

as described.

4. In combination with a normally-continuous telephone-line, an annunciator having an indicator and two electromagnets adapted to act independently upon the indicator to prevent its display, one of said electromagnets being included together with a source of current in the telephone-line, a normally-open local circuit including the other magnet and a source of current, and switch contacts adapted to close the local circuit when connection is made with the line, substantially as described.

5. In combination with a normally-continuous telephone-circuit extending from a substation to an exchange, a switch at the substation adapted to open the line during the use of the telephone, spring-jacks connected with the line at the exchange, an annunciator having an indicator and two electromagnets each adapted to prevent the display of the indicator, one of the magnets being included together with a source of signalingcurrent in the telephone-line,a normally-open local circuit including the other magnet of the annunciator, and switch-contacts adapted to close the local circuit at any spring-jack when connection is made therewith, substantially as described.

6. The combination with an elec'tromagnet of an armature-shutter pivoted at its lower edge and adapted to fall outward when unattracted, of a pivoted shield suspended before the shutter, an arm projecting beyond the pivotal point of the shield, and a projection upon the shutter adapted to engage the arm to throw the shield into a horizontal position, as described.

7. The combination with a telephone-circuit extending from a substation to an exchange and closed at the substation through a circuit of high resistance, a switch at the substation adapted to close the line during the disuse of the telephone through a circuit of lower resistance, an annunciator having two electromagnets adapted to act independently on its indicator to prevent the display thereof, one of said magnets being included together with a source of current in the telephone-circuit, and the other being included with a source of current in a closed local circuit, a clearing-out annunciator adapted to give a signal when its magnet is excited temporarily included with a source of current in a branch between the sides of the telephone-circuit, and means for opening the 10- cal circuit when the clearing-out annunciator is disconnected,s ubstantiall y as described.

8. The combination with an electromagnet and its armature, of a pivoted shield depending before the face of the armature and hid ing the same, and a hook carried by the armature, adapted to engage said shield near its pivotal point, thereby causing the display of the target or face of the armature when the armature is attracted, substantially as described.

9. The combination with an electromagnet and the armature thereof pivoted at its lower edge, of a shutter depending before the armature from its upper edge adjacent to the armature, an extension of the shutter above its pivotal point, and a hook carried by the armature engaging said extension, substantially as described.

In witness whereof I hereunto subscribe my name this th day of August, A. D. 1894.

CHARLES E. SORIBNER. lVitnesses:

THOMAS D. LOOKWOOD, V. M. BERTHOLD.

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