US1480241A - Machine-switching telephone-exchange system - Google Patents

Description

Janu 8 1924. I 1,480,241

H. P. cLAUsEN ET AL MACHINE SWITCHING TELEPHONE EXCHANGE SYSTEM Filed [Law Y 16, 1918 2 Sheets-Sheet 1 all I //7 yen 70/ MMA/fy.

Jan. 8 1924.

H. P. CLAUSEN ET AL MACHINE SWITCHING TELEPHONE EXCHANGE SYSTEM Filed July 1 1918 2 Sheets-Sheet 2 fly W A y- Patented Jan. 8, 1924.

UNITED STATES PATENT OFFICE.

HENRY P. CLAUSEN, OF IMOU'N'JI VERNON, AND CHARLES I. GOODRUM, OF NEW YORK, N. Y., ASSIGNOBS '10 WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

MACHINE-SWITCHING TELEPHONE-EXCHANGE SYSTEM.

Application filed m 16, 1918. Serial No. 245,145.

To all whom it may concern:

Be it known that we, HENRY P. CLAUsnN and CHARLES L. GOODRUM, citizens of the United States, residing at Mount Vernon,

6 in the county of VVestohester, State of New York, and at New York, in the county of New York and State of New York, respectively, have invented certain new and useful Improvements in Machine-Switching Tele- 10 phone-Exchange Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to special service systems for machine switching telephone exchanges.

In systems employing so-called manual working, that is, where operators are employed for answering calls and for setting up connections, certain special service features have been developedwhich are of great value, especially in rivate branch exchange working. One of t ese features is a means for summoning a particular person to the telephone when such particular erson is away from his instrument. Shou d a call come in to a private branch exchange and were the operator there requested to complete a connection to a particular person, say, for instance, the superintendent of the establishment wherein the private branch exchange islocated, and should the particular person be at that time away from his instrument, the operator, after an appro: priate interval, would use a special means for summoning such particular person. This special means is in the present day practice dissociated with the telephone sys tem and such service is not supplled by the telephone companies. It, however, is a valuable feature and one which, from its nature, should be retained in machine switching telephone exchan es installed for private branch exchange wor ing.

The object of the present invention is to provide means whereby a calling party may summon a particular person when such particular person is away from his instrument.

Accordingly, a signal circuit is wired up throughout the building in which the private branch exchange apparatus is installed whereby signals may be transmitted which will attract the called party wherever he is. This signal system is preferably in the form of a code signaling arrangement with one code representing each particular person who may be provided with this special SGI'VICB feature.

Associated with each telephone is a means for operating this signal circuit automaticallyso that, if a particular person who is called does not answer his telephone within a reasonable time, a simple manipulation of the dial switch under the control of which the connection is originally set up, will set the signal circuit in operation to transmit the particular code corresponding with the telephone station called. The invention is illustrated in the drawings in two figures. Fig. 1 shows diagrammatically a calling sub-station, a connector switch, a called substation and a signal bell code ringing apparatus, and Figure 2 shows a second calling substation adjacent to one of the bells on the call bell circuit.

Briefly, the operation is as follows: The calling subscriber at sub-station 1, desiring to communicate with theparty who should be at substation 2, sets up the connection in the usual manner whereupon the telephone bell at substation 2 commences to ring. If, after a certain period, the subscriber at substation 1 concludes that the party at substation 2 is not there, he will manipulate his dial switch from any one of the finger holds, whereupon the call bell apparatus, consisting of the constantly rotating cams 3 and 4 and the circuit 5 including the call bells 6 and 7, will be actuated. Thereupon, the bells 6 and 7 throughout the building in which this private branch exchange may be installed, will commence to ring in code. The party who should be at substation 2 hearing the ringing of the bells and recognizing the particular code as summons for himself, goes to the nearest telephone 8 in the building and calls a special number. This special number is one known to himself only andit connects him to a set of multiple terminals connected with his own line at substation 2. Thereupon, the ringing of the telephone bell at substation 1 is discontinued and conversation takes place between the calling substation 1 and the substation 8.

At the end of the conversation both parties hang up and the apparatus in the automatic switches is all restored in the ordinary manner. 7 It is'thoughtthe operation as a Whole may be more clearly understood through the following detailed description. I

The subscriber at substation 1, after removing his receiver from its hook, causes the extension of his line in the usual manner by automatic switches until the connector switch of Figure 1 is seized; thereupon, the calling line relay 9 will be energized-and in turn the first slow relay 10 Wlll be energized. A manipulation of the dial sw1tch at the calling substation 1 now causes the line relay 9 to vibrate its armature and a circuit on each back stroke is set up from ground, through the armature and back contact of the relay 9, the right-hand armature and front contact of the relay 10, thereafter in one direction through the winding of second slow relay 11, to battery and round, and in the other direction through side-switch wiper 12 in its first position, primary magnet 13, to battery and ground. Primary magnet 13 responds to each impulse separately but the slow releasing relay 11 responds to the train of impulses as a whole. Primary magnet 13 causes the stepping of the brushes 14c, 15, 16 and 17 in a primary direction' whereby a particular group of lines is selected. Slow releasing relay 11 by attracting its armature energizes the escape magnet 18 through a circuit extending from ground, through armature and back contact of relay 19, winding of relay 18, right-hand arm ature and front contact of relay 11, to battery and ground. At the end of this series of impulses, slow releasing relay 11, being deprived of energizing current for a suflicient length of time, retracts its armatures and in so doing opens the circuit for the escape magnet 18, whereupon the sideswitch wipers are passed into their second position and the connector switch is ready to receive the last set of impulses. When this is sent in response to the manipulation of the dial switch at the calling substation 1, the armature of-relay 9 is vibrated as before and upon each back stroke a circuit is established which now extends through the secondary magnet 20 instead of, as before, the primary magnet 13. Slow releasing relay 11 is energized, as before, and the escape magnet 18 is also energized as before. Upon each energization of the secondary magnet 20, the brushes 14 to 17 inclusive, are stepped in their secondary direction until the selected line is reached. "whereupon a test is made. At the end of this series of impulses, slow releasing relay 11 again retracts its armature and by deenergizing the escape magnet 18 causes the side-switch wipers to move into their third position.

It will be noticed that escape magnet 18 is slow to release and that therefore before the side-switch wipers have passed to their third position, a circuit is established from the second position contact of the side-switch nector switch.

e an be returned to normal but the other automatic switches in the train will not be released since the test wire will be grounded over the left-hand winding, left-hand armature and contact of release magnet 23, the left-hand armature and front contact of relay 10 and the test terminal 25 of the conlthrough this circuit the release magnet will remain energized and thereupon a busy tone will be transmitted from the source of busy tone BZ to one side of the line and thence to the calling line in the usual manner. If, on the other hand, the called line is found to be idle, then upon the release of the escape magnet 18, the sideswitch arms would have been advanced to their third position and the escape magnet 18 would again be energized over a circuit from ground, the armature and contact of relay 19, winding of escape magnet 18, sideswitch arm 26 and its third position contact, to battery and ground. Through the energization of escape magnet 18 the bell at the called substation 2 is rung through the flow of ringing current at the contact of escape magnet 18, through its armature, winding of relay 19, third position contact and sidesWitch Wiper 27, brush 15,- terminal 28, the line to the called substation 2 through the bell at the called substation back over the other side of the called line, terminal 29. brush 14, side-switch arm 30 and its third position contact, front contact and armature of line relay 9, to ground.

Should the called subscriber be within hearing distance of his own telephone bell and should he in answer to its summons remove his receiver from his hook, he would cause a suflicient flow of ringing current through the relay 19 to open the circuit of the escape magnet 18, whereupon the sideswitch wipers would be'passed into their fourth positions and the conversational circuit established in the ordinary manner.

During the conversational period the calling subscriber is supplied with talking current through the windings of the line relay 9 and the called subscriber is supplied with talking current through the windings of the called supervisory relay 31.

At the close of the conversation the calling subscriber by hanging up his receiver deenergizes the line relay 9, in response to which relay 10 becomes deenergized, whereupon a circuit is established from ground through armature and back contact of relay 9, righthand armature and back contact of relay 10, left-hand armature and back contact of relay 10, the off-normal contact 22, the righthand winding of release magnet 23, to batter'v and ground, whereupon the connector switch is released in the manner hereinbefore described.

If, on the other hand, the subscriber who should be at substation 2 is in some other part of the building and does not answer the summons of his telephone bell, the calling subscriber 1 may manipulate his dial switch from any one of its finger holds, thereupon, remembering that the side-switch wipers are in their third positions during the ringing period, a circuit will be established from ground, through the armature and back contact of relay 9, the right-hand armature and front contact of relay 10, the side-switch wiper 12 and its third position contact, the brush 17, terminal 32, winding of relay 33, to battery and ground. Relay 33 locks up over a circuit from battery and ground through the winding of relay 33, its left-hand contact, the back contact and armature of relay 34, terminal 24, brush 16, sideswitch wiper 21, and its third position contact, to ground. This closes a circuit including the spring contact 35 working in conjunction with the code ringing cam 3, whIch is constantly rotating, through the front contact and right-hand armature of relay 33, thence over the circuit 5 including the code ringing call bells 6 and 7. The call bells throughout the building, illustrated by two, that is, Nos. 6 and 7, ring continuously until the called subscriber is attracted thereby, and proceeds to set up a connection to his own line. This he may do by going to any substation such as No. 8 and dialing a special number. In response to the dialing operations at substation 8, a circuit will be established between the substation 8 and the connector switch 36 which is in all respects similar to the connector switch in Fig. 1.

In response to further manipulations of the dial at substation 8,.the brushes 37, 38, 39 and 40 may be set on the special number corresponding to the called subscribers substation. The terminals 41 and 42 complete circuits which willcause the ringing current being transmitted at present from both connector switches to be cut off and to cause the side-switch wipers of both connectors to be advanced to position 4. In one case this circuit may be traced from the source of ringing current connected to the contact of escape magnet 18 through its armature, winding of relay 19, third position contact and side-switch 27, the brush 15, terminal 28, the conductor 44, terminal 41, brush 37, side-switch wiper 45 and its third position contact, front contact .and armature of line relay 46, to round. This causes the energization of t e relay 19 and as before described the passing of the side-switch wipers of the connector switch shown in Fig. 1 into their fourth ositions. In a similar manner the relay 4 in the connector switch 36 is energized over the conductor 48 and the side-switch wipers of the connector 36 are passed into their fourth positions, whereupon conversation between the substation 1 and the substation 8 may proceed.

As the connector switch 36 sets its brushes 37 to 40 inclusive, on the terminals 41, etc., representing the special number corresponding with the called substation 2, a circuit is completed from ground, through third position contact and side-switch wiper 49, brush 39, terminal 43, winding of relay 34, to battery and ground. Relay 34 in attracting its armature opens the circuit of the code ringing control relay 33, whereby it is deenergized and the code ringing on the circuit 5 is cut off.

At the close of the conversation when the receiver at the substation 1 is replaced on its hook, the calling relay 9 is deenergized and the connector switch in Figure 1 is released, and when the receiver at substation 8 is replaced the calling line relay 46 is deenergized and the connector switch 36 is released.

Another s'ubstation 50 is shown to illustrate how this special service may be supplied so that an oflicial of a higher rank may take precedence over anofiicial of a lower rank. Should a call come in for an ofiicial whose substation is No. 50 and in the manner described should the call bell circuit 5 be set in operation through the energization of relay 51, the operation may go on as herein described. If, however, before the oflicial who should be at substation. 50 has picked up the call to his telephone in the manner described, another call comes in for the official who should be at substation 2 and who is presumed to be of higher rank, then the energization of relay 33 will cut off from 'the call bell circuit the train of impulses set up by the cam 4 and substitute therefor trains of impulses set up. by the cam 3. In this manner the higher of the two ofiicials will be served first.

The call bell circuit 5 may be of any suitable form but is here merely indicated as a cam disc such as 3 or 4 which operates the spring contact to close the circuit in a characteristic manner. A grounded contact is shown in cooperative relation with the spring 35 and the circuit 5 proceeding from the call bell 7 is shown in a dotted line indicating that it goes through several more call bells such as 6 and 7 and thence to a suitable source of battery supply. Instead of call which will attract the attention of a person, may be used.

Another valuable special service feature present in this arrangement is the following: Terminals 29, 28, 24 and 32 of the called substation 2 represent one set of the multiple terminals appearing in the connector switches which have access to this line. Terminals 41, 42 and 43 represent one set of another series of multiple terminals which appear in the same connector switches. The first set may be reached through dialing one number and the second set may be reached through dialing another number. The first set are the regular terminals of the substation 2 and are those which are reached through the calling of this sub-station by its listed number. The number used for reaching the second set is to be known only to the subscriber who should be at substation 2 and anyone else Whom he may trust with this number.

When a connection is established to substation 2 through the first set of terminals 29, 28, 24 and 32, calls to this substation through this set of multiple terminals are barred, but calls to the substation through the other set of multiple terminals are not barred. Since the test terminal 43 remains ungrounded, therefore, a trusted lieutenant may break in on the circuit of substation 2, even though it be busy in an established connection. If, however, such trusted lieutenant has established a connection through the number known only to himself and his superior, that is, through the terminals 41 to 43, the grounding of the terminal 43, and consequent energization of the relay 34 will bar not only calls to this substation through the group of multiple terminals of which 41 to 43 are a set, but also calls coming in through the roup of terminals of which 29, 28, 24 and 32 are a set. The energization of relay 34 through its front contact, grounds the multiple terminal 24 and the terminal 43 is grounded through the side switch wiper 49 in its fourth position.

What is claimed is: o

1. In a telephone system, telephone lines each including a calling signal, a secondary calling signal common to said lines, means individual to each of said. lines for automatically operating said secondary calling signal in a difierent characteristic manner, means for selecting said lines and operating said signals, and means responsive to an additional operation of said selecting means for subsequently causing the actuation of said first means.

2. In a telephone system, telephone lines, a signal individual to each of said lines, a signal common to said lines, separate means for actuating said common and said individual signals, machine switching means for interconnecting said lines, means whereby auser a first one of said lines may call a second one or said lines and actuate said individual signal of said second line, means whereby said first line may thereafter actuate said common signal, means whereby a third one of said lines may establish a conversational circuit to said first line, and means responsive to the establishment of said conversational circuit for causing the operation oil said individual signal and said common signal to cease.

3. ln a telephone system, telephone lines, an individual signal for each of said lines, a common signal for said lines, means associated with each of said lines for operating said common signal in a distinctive manner,

machine switching means for establishing a connection between a first one of said lines and a second one of said lines, means included in said machine switching means for causing said individual signal of said second line to operate, means under control of said calling line for subsequently causing said common signal to operate, means whereby a third one of said lines may establish a conversational circuit to said first line, and means responsive to the establishment of such connection for causing the operation of said individual and common signals to cease.

4. Tu a telephone system, telephone lines, an individual signal for each of said lines, a common signal for said lines, means associated with each of said lines for causing said common signal to operate in a distinctive manner, machine switching means for interconnecting said lines, means included in said machine switching means responsive to the establishment of a connection between two of said lines for causing the individual signal of the called one of said lines to operate, means under control of the calling one out said lines for thereafter causing the common signal to operate in such amanner as to identify the called one of said lines, means whereby a second connection may be established through said machine switching means between a third one of said lines and said pair of lines involved in said first-mentioned connection, and means responsive to such an established connection for causing the operation of said individual and common signals to cease.

5. lln a telephone system, telephone lines,- a signal individual to each of said lines, a signal common to said lines, means individual to each of said lines for causing said common signal to operate in a distinclllU common signal to operate in a predetermined order of preference to identify said lines whose individual signals are operating. 6. In a telephone system, telephone lines,

5 a signal common to said lines, means asso ciated with each of said lines for causing said signal to operate in a distinctive manner, and means responsive to the simultaneous operation of several of said lines for causing said common signal to identify each of said lines in a predetermined order of preference.

7. In a telephone system, telephone lines,

each includin a primary calling signal,

means for cal ing said lines and actuating said signals a secondary calling signal common to said lines, and means dependent on the maintenance of an established connection to one of said lines for subsequently selectively actuating said secondary signal.

In testimony whereof We hereunto sub scribe our names this 8th day of July A. D.,

HENRY P. CLAUSEN. CHARLES L. GOODRUM.

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