US283354A - Telephone local-call instrument - Google Patents

Description

(No Model.) 2 Sheets-Sheet 1.

' W. NICHOLS.

TELEPHONE LOCAL CALL INSTRUMENT.

e ted Aug. 14, 1883 MENTOR wzeem may! Attorney u. PETERS. Halal-WWI: Wnbinglnn. a. c.

2 Sheets Sheet No Model.)

' W. NICHOLS.

TELEPHONE LOCAL CALL INSTRUMENT.

Patented Aug. 14, 1883 llll l.

N4 PETERS. mutm m aer. Wmiw n. c.

UNITED 'STATEs PATENT OFFICE,

ILL-TAM NICHOLS, OF BOSTON, MASSACHUSETTS.

TELEPHONE LOCAL-CALL INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 283,354, dated August 14, 1883.

Application filed October 14, 1882. (No model.)

To ail-whom it may concern:

Be it known that I, XVILLL M NIcnoLs, of Boston, Suffolk county, Massachusetts, have invented a new and useful Improvement in Switches for Telephonic Circuits, of which the following description, in connection with the accompanying drawings, is a specification.

My invention has for its obj ectto secure secrecy, safety, simplicity, and celerity in communication between subscribers on the same telephone-line, or different lines temporarily in circuit. It applies to that class, of stationinstruments forming a series in which a movable switch is an element in the connections, making a telephone a part of the circuit.

7 It consists in a stop operated to hold such a switch from moving out of connection in re.- sponse to any agency actuating corresponding switches in the instruments of the series when ever subscribers on the same line or on different lines are to be kept in communication with each other, the cutout.

It also consists in an automatic switch and a single connection by which a telephone is put in circuit only when a movable switch rests on the local switch or bell-shunt of an instrument in a series.

.l'n carrying out my improvement I have used it in connection with the local-call instrument for telephone-lines described in Patents Nos. 235,058 and 265,454, issued to James I Stabler November 30, 1880, and October 3, 1882, respectively, and so much of the same as is necessary to illustrate my invention is figured in the accompanying drawings. The lines and connections, so far as concerns the first part of my invention, are the same as shown and described in said patents, and reference is hereby made to said patents for details of construction not necessary to be specified herein. 9

lnthe patents referred to each instrument in the series has a dial, index, two electromagnets with helices wound in opposite directions, between which vibrates a polarized armature carrying a standard with pawls operating a ratchet-wheel on the axis of themdex. The dial has a conductor-rim cut away opposite a unison-shunt and a local bell-shunt in each instrument. The unison-shunt: is located alike in each instrument. The local or telephones of the rest being" bell shunt is located accordingto the position of the particular instrument in the series. The index sweeps over the rim and interposed shunts, is always in the circuit, and is actuated by means exclusively under the control of the operator at the central oflice. A to-and-fro current sent from the central oflice over the line through the motor-magnets causes the vibrating-armature to move the index in each instrument synchronously with those of the others in the series. The operator, either manually or by c n automatic device at the central office, grounds the current and halts the index in its revolution at any desired point.

The index extending beyond the rim of the dial, a detent-arm mounted on the vibrating armature of an electro-magnet normally intervenes in its path at a unison-point'located alike in each instrument. The unison-shunt has an electrical connection with this detent-magnet. The local shuntconnects with the bell-magnet. The current which actuates the index has not strength to affect the detent-magnet or the bellmagnet, but if the index be on the unisonshunt or on a local shunt, the operator, by applying a special electric instrumentality, can send over the line a current of greater strength and of a single polarity, which acts to draw aside the detent and release the index of each instrument, or to sound the bell of a particular instrument, as the case may be.

The rim and shunts being alternately in the linecircuit, the-device outlined above, and as covered by Patent No. 235,058, enables the operator to bring the indexes of all the instru ments in the line into unison to move and stop them together, to sound the bellcall of any instrument, and to out out the bells of the rest. The arrangement of this device, however, permitted' conversation between two persons to be heard and interrupted by the voluntary act of others, and gave no visual notice of theline IOU cording as the index rests on the one or the other of these shunts. This makes it possible, when two persons on different lines are talking, to secure the same privacy ofcommunication to those on combinationdines that is e11- joyed by subscribers having individual connection with the main office. The indexes of all the instruments are normally kept at the unison-point when the line is not in use, constituting a visible signal. By a connection with the unison-shunt, when the receiver is 011 its hooklever, a subscriber can put the generator of his instrument in circuit and send a current over the line to drop the annunciator By the telephone-connection with the unison-shunt, on removing the receiver, he communicates his instructions to call a person on another line to the operator.

The latter moves the index of the subscriber s instrument upon its local shunt, and after a like operation on the proper instrument on the other line sounds the bell of the person to be called.

shunts the telephones of these two instruments are put in circuit. The telephones, bells, and generators of the other instruments on the two lines are cut out. Onthe other hand, after notifying asubscriber that another 011 the same line desires to communicate'with him, it is .necessary for the operator first to bring all the indexes to the unison-point, then to release the detents in order to advance the indexes the distance of one station upon an extension of the unisoirshunt, or on a shunt located alike in each instrument and having an automatic connection with the telephone when the receiver is removed from its hook. This provides visual notice of the line being in use to prevent unwitting"overhearing or interruption, but avails nothing against willful intermeddling, and secures no secrecy.

Figure l of the accompanying drawings shows a front elevation of an application of my invention to the local-call instrument, the operation of which has just been explained. Fig. 2 shows aside elevation. top planview. Fig. 4 shows a modified form of the same and certain details of construction.

Fig. 5 is a diagram of the circuits of Fig. 1'

simplification of the connections of the unisonshunt given in Fig. 5, which constitutes the second part of my invention.

D represents the dial; 1, the index-switch;

but striking against the contact-spring z when By their connections with the local Fig. 3 shows a' the hook-lever is-elevated, thereby closing the primary circuit of the transmitter, with which 2 and z are connected by wires q and q, re-

spectively; q, the secondary circuit through '1), the wire from conductor-rim R to contactspring 0 and line 0,- p, the wire from unison I shunt U to the detent-magnet T and switchspring k,- t, the wire from switch-spring 7c to the generator-frame, contact-spring c, and line 0; u, the wire from local shunt L'to contactspring 9; I 'U, the wire from switch-spring h to contact-spring b and bell-magnet V; r, the direct connection between the detent-magnet and generator in place of the connection by wire 1", hook-lever, switch-spring k, and wire t. The other letters are the same as those indicating like parts in Patent No. 265,454.

Referring to Figs. 1 and 5, the current comes infrom theline m byway of the motor-magnets B O and axis K to the index I, which is always in the circuit. The conductor-rim R is cut away opposite the unison-shunt U and local bell-shunt L. WVhen the receiver hangs upon its hook, it throws down the pivoted. hooklever H upon the switch-spring k. If the index be on the unison-shunt U, the current hook-lever H, switch-spring 75', wire 25, gener ator-frame, continuation of wire 1, and contactspring 6 to .line 0. A subscriber can put the generator of his instrument in this circuit to call the central-office operator. If the index be on the rim R, the current is short-circuiiezl, passing by the wire 12 to contact-spring c, and line 0. If the index be on the local-shunt L, the currentpasses by wire a to contact-spring g, switclrspring h, wire '0, contact-spring b, bell-magnet V, and contact-spring o to line 0.

The rim, unison, and local shunts being alternately in circuit, according to the position of the index, the operator sends from the central office a current of a single polarity and of a greater strength than the to-and-fro current used to move the index, which, through the connections above set forth, acts through the magnet T to operate the detent Q, to release the index synchronously in each instrument of the series, or to sound the bell in any desired instrument, according as the index rests on the unison or on the local shunt. A to-and-fro current, too weak to effect the dc tent-magnet or bell-magnet, sent over the line from the. central office causes the armature A to vibrate between the motor-magnets. B O, and, by means of the standard F, pawls E E, ratchet-wheel G, and axisK, to move the index synchronously with those of the other instruments of the series, over the dial-rim and interposed shunts, it being halted upon its local shunt at the will of the operator by grounding the current at the central ofiice,

IIO

while the indexes of the other instruments are halted at corresponding points on their dialrims.

A double connection with the unison-shunt and the local shunt, when the receiver is taken from its hook, puts the telephone in each instrument in circuit,according as the index rests upon one or the other of these shunts. This double connection and its action are as follows: \Vhen the receiver TV is removed, the hook-lever H is raised by its spring 5 to break contact with switch-spring k and make contact with switch-spring s, which connects with the telephone. The lever at the same time acts to .throw up the contact-spring 51',

causing it to break contact with switch-spring h and make contact with switch spring i, which connects with the telephone. If the index be on the local shunt L, the current passes thence by the wire n, contact-spring g, and switchsprin'g i to the telephone. 'If the index be on the rim, neither thetelephone nor the generator can be put in circuit.

Passing now to the features constituting the first part of my invention In Fig. 1, S is an arm or stop pivoted upon the frame M of the motor-magnets B C and moving in a plane at right angles with that of the movement of the hook-lever H,- on which a receiver, W, is indicated as hanging; When the receiver is removed from its hook, the lever is thrown up by the spring 2:, in consequence of which. the inclined stud O of the hook-lever (shown in Figs. 1 and 2) throws forward the lower extremity of the arm S to rotate the latter on its pivot. This, as shown in Fig. 3, operates to cause the upper extremity of the arm or stop'to intervene in the path of the pin P, {shownin Fig. 4,) inserted in the anterior face of the ratchet-wheel G on the axis K of the index I. I

The ratchet-wheel and pin are adjusted to each instrumentwith relation to the point at which the index in its movement over the dial rim R encounters thelocal shunt L.

The spring attached to the frame, throws the stop out of engagement with the pin whenever the hook-lever is depressed by the restoration of the receiver to its hook.

By the telephone-connection with the union shunt, on removing the receiver, a subscriber communicates his instructions to call another on the same line to the operator. The latter moves the index of the proper instrument upon its local shunt, and sounds the bell of the person to be called. In so doing he moves all the other indexes in the'h'ne to a correspond ing point on their dial-rims, except that of the first subscriber. The automatic operation of the stop on the receiver, being removed from its hook, arrests this index in its passage over its local shunt. By their connections with the local shunts the telephones of these two instruments are put in circuit. The telephones, generators, and bells of the other instruments on the line are cut out.

Instead of the arm or stop S being pivoted upon the frame M, as shown in Figs. 1 and2, it may be fixed, as shown in Fig. 4, to the hooklever, and of such a shape as to be thrown up in the path of the pin P when the lever is raised on the removal of the receiver.

In the foregoing applications of my invention to the localcall instrument previously described the electrical connections are the same as those set forth in Patent No. 265,454.

It is evident that a stop operated manually.

through the exterior case of the instrument may be made to intervene in the path of the index; but this method has obvious objections which do not pertain to the automatic stops above described. A stop pivoted on the frame M and operated by the hook-lever may be also made to engage directly'with the index, and various equivalents to effect the same object as the preferred methods already given will suggest themselves to mechanical minds.

Among subscribers on the same line it will be seen that the improvement set forth above secures secrecy of communication between particular persons by cutting out the telephones of the others, safety from interruption by cutting out the other generators, simplicity of construct-ion by doing away with the need for an extension of the unison-shunt or the establishment of a special conversation and sig nal shunt, and celerity of operation by dispensing with three maneuveis on the part of the central-office operator.

Another feature of my invention provides a simplification of the electrical connections described above and shown in Patent No. 265, 454. In place of the double connection of the tele phone with the unison-shunt and local shunt in each instrument in the series, a single connection with the local shunt is substituted.

The connection between the unison-shunt and detent magnet with the hook-lever and alter ate connections with the switch-spring It and the generator-frame and with the switch-spring s and the telephone are dispensed with. The local shunt L connects with the contactspring g by the wire a. The switch-spring h connects with the bell-magnet by the wire 1;, and the switch-spring 71 connects with the telephone.

When the receiver XV hangs upon its hook and depresses the pivoted hook-lever H, the contact-spring g rests upon the switchspring h. hen the receiver is removed, the lever rises and throws up the spring 9 against the switch spring i.

p In place of the connection between the detent-magnet and the generator-frame by the wire r, hook-lever, switch-spring k, and wire it, a direct connection. by the wire '2" is substituted.

The current comes in from the line m by way of the motor-magnets B C to the index I. If the index be on the unisonshunt U, (see Fig. 6,) the current passes by the wire '2', detent-magnet T, and wire r to the generator,

ceiver WV is removed and the lever elevated,

the contact between 9' and h is broken, and then the current goes by way of the switchspring 4/ to the telephone, and thence by wire (1 to line 0.

The operation of this form of my improve-- ment is as follows: A subscriber, by the con the central office, and removesthe receiver from its hook. The operator, on receiving the call, moves the indexes of the other instru ments on the line through one revolution, the subscribers index being arrested on its local shunt and his telephone put in circuit. The subscriber then communicates his instructions to call another on the same line to the opera tor,-who moves the index of the proper instrument upon its local shunt and sounds the bell of the person to be called. If the instructions are to call another person on a different line, he performs a like operation on the proper in.- strument on that line after moving the indexes on the first line from the unison-point. In either case by their connections with the local shunts the telephones of these two instruments are put in circuit. The telephones, bells, and generators of the otherinstruments on the same line or on the two lines are cut out.

NVhile the device has been shown in its particular application to the instrument covered by the patents referred to, it will be seen that it may be adapted to various apparatus of a similar character, and that the invention is applicable to all instruments having the general mode of action above specified.

The present invention is restricted to-those matters and things which areclaimed herein, and as to all features, devices, or combinations which are shown or described, but not claimed, the right is reserved to make the same the subject of a separate application.

Having thus described the nature, construction, and operation of my invention, what I claim as new, and desire to secure by Letters Patent, is- I 1. In a local-call instrument for telephonic purposes, an electricallyractuated switch connecting the telephone with the line, in combination with a stop for said switch, operated independently of the electric influence to maintain the switch in connection, substantially as described and shown, whereby connectionbe tween two instruments may be positively main= tained at will.

2. In a local-call instrument for telephonic purposes, a rotary index whereby the instrument is placed in and out of circuit, and elec trically actuated devices, substantially as shown, for moving said index, eombined with a stop mechanism, substantially as described, independent of the electric influence, to arrest the movement of the index and hold the same in electric connection, whereby the instrument'may be maintained in circuit, notwithstanding the tendency of the electric current to move the index.

3. In a telephonic exchange system, a localcall instrument containing a revolving index, whereby the telephone is placed in and out of circuit, combined with a stop device for said index, and means, substantially as described, whereby the stop is thrown into and out of action by the removal or replacement'of the receiving-instrument.

4c. In atelephonic exchange system wherein a series'of individual subscribers call-instruments are connected with a central station, the combination, in such instrument, of a moving index electrically actuated from the central office, and serving to place the telephone in and out of circuit, a hook-lever whereby the receiving-instrument is thrown into and out of connection, and a stop device actuated by said lever to arrestthe movement of the index, whereby the telephone may be positively retained in circuit.

5. In atelephonic exchange system, the combination, with the main line, of a series of local-call instruments, each instrument con taining an electricallyactuated switch operat ing at a different timefrom like switches in the other instruments, -to establish a connection with themain line, combined with a mechanical stop device therefor, substantially as described, whereby the switch in any of the series may beheld mechanically and positivelyin connection, and thus the corresponding instru ment maintained in circuit indefinitely.

6. In a telephonic exchange system, the combination, with themain line, of a series of local-call instruments, each embracing the following elements: the electrically actuatedmain-line switch, closing at a different time from the like switchesin the otherinstruments of the series, the local shunt, the telephone con necting with the main line solely by said switch and shunt, and the stop devices, substantially as described, for the main-line switch, operating independently of the stop device in the other instruments and of the electric influence, whereby either instrument of the series may be maintained in circuit at will.

7. In a local-call instrument for telephonic purposes, the electrically-actuated rotary in-' dex, whereby the instrument is placed in and out of circuit, combined with a manual stop device, substantially as described, to arrest the motion of said index and hold the instrument in circuit, whereby communication between two parties maybe maintained at will.

8. -Ina telephone local-call instrument, a

movable switch in the line-circuit, a local-station shunt, acontactspring, g', in connection with said shunt, combined with it pivoted lever whereon the receiver may behung, 2% switchspring, i, anda stop device toarrest the motion cf the main-line switch at a given point, substantially as described, whereby the telephone may be maintained in circuit through the medium of 2t single connection at will;

-9. In a local-cell instrument such as described the combination of the unis0nshunt, wire 1-, detent-maignet, T, and Wire a", leading dircctlyifrom said magnetto'the generator.

10. In a telephonic exchange system, the

combination, with the main line, of a series of I 5 10ca1- cell instruments containing synchroncuslycperating switches connecting thesame with the main line, combined with stop-devices for said switches, located one in each instrument, and arranged as described, to operateindependent of the electric influence, whereby either instrument may he held in circuit independently of the action of the others:

WILLIAM NICHOLS.

Witnesses: I

PHILIP T. DODGE, CHAS. F. MYEns.

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