US2222751A - Communication system - Google Patents

Description

Nov. 26, 1940. G, MICHAELSON 2,222,751

COMMUNICATION SYSTEM Filed June 3, 1938 5 Sheets-Sheet l Fig.1.

/ f I III] [I I CIT/3178 5 N l/WfA I'OA" GEORGE MzcHAEbsoN 5, 1940' G. MICHAELSON 2,222,751

COMMUNICATION SYSTEM Filed June 5, 1958 s Sheets-Sheet 2 Fig. 5.

20 51 54' 5 30 Y /65 W l [7 57 /63 H- mv E N TO R GEORGE MIGHAELSON Nov. 26, 1940. G. MICHAELSON 2,222,751

COMMUNICATION SYSTEM Filed June 3. 1938 Sheets-Sheet 3 Fig.6.

r r L /63T I8 /50 L \1 l i Z U/ 57 //63 2 24 O 5 N 25 53 4 56 46 48 41 P 4] Q L N 60 Mr- I 1 3 4 7 b 58 57 61 2 x 15 I E 6 \NVENTOR GEORGE MICHAELSON ATTORNEYS NOV. 26, 1940. MICHAELSQN 2,222,751

COMMUNICATION SYSTEM Filed June a, 1938 s Sheets-Sheet 4 STE Z480 'INV EN TOR GEORGE MICHAELSON ATTOIW IFKS NOV. 26, 1940. WCHAELSON 2,222,751

' COMMUNICATION SYSTEM Filed June 5. 1938 5 Sheets-Sheet 5 n u-m nwz-wrwa GEORGE MICHAELSO N Patented Nov. 26, 1940 UNITED STATES PATENT OFFICE Application June 3, 1938, Serial No. 211,645 In Great Britain June 17, 1937 Claims.

This invention relates to telephone systems and to apparatus for use in connection therewith for the purpose of enabling signals, codes or messages to be transmitted over the line and re- 5 corded.

The chief object of the invention is to provide a simple and efficient means which can be utilised for the purpose of advising a subscriber, upon his return, of the fact that he has been called during 1(1 his absence from the home, ofiice or other building in which his telephone is located.

A further object of the invention is to provide a simple and efficient means adapted to insure that, when a call is unanswered, a record will be made of the callers number and/or his message upon means provided for the purpose at the calledsubscribers end.

According to the invention each subscriber or certain subscribers is or are provided with means adapted to be brought into operation automatically or by manually operable means for transmitting along the telephone line a predetermined signal or group of signals having characteristics which render them capable of being recorded and identified at the receiving end by a subscriber.

who is not available at the time of the call.

The invention may be carried into efiect in various ways and, in its simplest form, it comprises means located at the senders end of the line adapted automatically to transmit over a line a signal or signals which is or are characteristic of the senders telephone number or tele-,

phone number and exchange and means located at the receivers end for receiving such signals and making a record of the same.

In the preferred embodiment of the invention, the sending end of the line is equipped with an oscillatory, rotary or other movable member adapted to influence the character of a series of electrical impulses transmitted along the line so as to render them characteristic of that particular senders identification number or of his number and exchange area. The aforesaid movable member may be arranged so that it is adapted to be brought into operation immediately the sender lifts his receiver or after a predetermined delay period. Alternatively, the arrangement may be such that the movement of the said mem-- ber or the commencement of its movement is un- 50 der the control of the sender. The character of the impulses may be varied by varying the nature of the movement imparted to the movable member or provision may be made for utilising different portions of the movable member or of its movement for obtaining the varied impulses.

The aforesaid member may be preformed or shaped to enable the same to be utilised for the purpose in view and may comprise a rotary member or drum the peripheral surface of which comprises parts having differing electrical conducting 5 characteristics, e. g. conducting and insulating parts, formed to correspond with, or to formulate signals which correspond with, the characteristics of the elements or digits of the signal, telephone number or message to be transmitted.

At the receiving end of the line, there may be provided a record sheet or strip and means such as a marker, perforator or the like for co-operating therewith to produce a record from which the signal or message can be identified. For example, means such as a solenoid may be provided at the receiving end of the line and the arrangement may be such that each time an impulse is produced at the sending end, the solenoids will be brought into operation to cause the marker, 20 perforator or the like to function. The record sheet or the like may conveniently be carried by a drum and, if desired, means may be provided for enabling the drum to be rotated in a step-bystep manner during or at the termination of each movement of the oscillatory member at the transmitting end.

In order that the said invention may be clearly understood and readily carried into efiect, the same will now be more fully described with reference to the accompanying drawings which illustrate diagrammatically various circuit arrangements suitable for adoption at subscribers stations required to be equipped with means for enabling the invention to be carried into effect.

Figure l is a schematic View of a portion of a telephone circuit embodying the present invention.

Fig. 2 is a diagrammatic side view of an impulse transmitting mechanism. 0

Fig. 3 is a diagrammatic side view of an impulse recording mechanism.

Fig. 4 is a modified form of impulse transmitting and receiving mechanism,

Fig. 5 is a View similar to Fig. 1 of a modified 45 circuit.

Fig. 6 is another view similar to Fig. 1 of a further modified circuit.

Fig. 7 is another view similar to Fig. 1 of still another modified circuit.

Fig. 8 is still another view similar to Fig. 1 of a still further modified circuit.

In Fig. 1 of the accompanying drawings, A indicates one side of a telephone transmission line and B indicates the other side thereof. Also C indicates the subscribers bell arranged in the usual ringing circuit which may be earthed at or as in some cases, may return via the line B. In the ringing or other warning circuit is arranged a pair of relays or electro-magnetically operable units a and b, one of which is adapted, when energised, to open a normally closed switch whilst the other is arranged so that when. it is energised, it is adapted to attract one end of a switch lever d, which may be normally in the off position, and to cause the same to move about its central pivot and to engage a contact e arranged in series with an electro-magnetic device G which forms a part of an impulse recording mechanism. The switch a, the electro-magnetically operable unit b and the midpoint of the switch lever d are also joined in series by a lead 1 the other end of which is connected with a suitable point in the subscribers receiver or receiver cord 9, or to a convenient point on the line 13. Hence it will be seen that, upon energisation of the subscribers ringing or warning circuit the switch 0 Will be opened and the lever d will be moved into contact with the contact 6, thus allowing the bell C to function in the normal manner. Immediately, however, there is a pause in the ringing or warning signal, the switch 0 will close again. In comparison with unit a, the unit b is relatively slow acting with the result that the lever 11 will for a short period remain in contact with c after the switch 0 has closed again. During this period, a circuit through the called subscribers receiver, his lead and the electromagnetic device G of his impulse recording mechanism is closed and I such circuit is connected through the line and the exchange with the calling subscriber whose impulse transmitter is now connected in the circuit through his switch (1 which may be closed by manually operable means. At this stage, the two 40 subscribers are interconnected through the exchange in the same manner as when the line is available for speech currents so that as the calling subscribers impulse transmitting mechanism is actuated, the called subscribers recording 45 mechanism is caused to function for recording purposes. Hence, it will be seen that the invention providesa simple and convenient arrangement for enabling the ringing or other warning current to prepare the called-subscribers circuit arrangement to be connected, either immediately or through the usual exchange connections, with the calling subscriber for transmitting, receiving and for recording, and to enable the same to be brought into operation for recording duringthe pauses in the different phases of the ringing or other warning signal so long as the latter is continued. Alternatively, the relays may be arranged and the circuit arrangement varied so that the recording circuit is prepared for functioning by 60 the operation of the ringing or other Warning signal and the latter prevented from continuing to function until the message has been completed. According to another alternative arrangement, the relays and other elements may be arranged so that the recording is caused to take place at the same time as the functioning of the bell or other warning signal.

The impulse recording mechanism and the impulse generating mechanism may comprise a V- shaped or hair-pin like member pivotally mounted at K and having an armature I50 and two downwardly extending arms H and L arranged for movement over the surfaces of two rotatably mounted drums P and Q. The recording arm L 75 may be provided with a suitable marker arranged so that, when this arm is attracted by the electromagnetic device G and the arm is caused to move out of its normal plane of movement, the marker will be brought into contact with a sheet of paper or the like carried by the drum Q.

The drum P may be provided with parts of differing electrical conducting characteristics, e. g. conducting and non-conducting areas or strips for the purpose of enabling the arm H to generate or formulate signals which are characteristic of the senders telephone number or other signal to be transmitted and, upon the closing of the receivers switch 0, which thus signals the exchange whereupon the usual connections between the two subscribers are made, the impulses being formulated by the senders drum P and its associated arm H will pass to the device G of the impulse recorder of the called subscribers instrument to actuate the marker carried by the arm L as the latter moves across the strip carried by the drum Q in synchronism with the movement of the arm H at the calling subscribers end of the line. For the purpose of enabling the two V- shaped or hair-pin like members to step over the non-conducting areas, each may be provided about its pivotal support with an upwardly and/or downwardly extending arm terminating in an adjustable weight W on a spring and the said arm or another arm coupled therewith may be utilised as the armature of an electro-magnetically operable device consisting, as shown in Fig. 1, of two electro-magnets F and F which are also so arranged and connected in circuit that they are adapted to be actuated by the impulses being generated or formulated by the calling subscriber. That is to say, at the called subscribers end, the impulse recorder and the electro-magnets Fand F are connected for intermittent operation in series with the line that carries the impulses being formulated by the calling subscriber, the said electro-magnetsbeing actuated alternately. The movements of the mass W allows its equivalent mass L time to change its plane of oscillation and enables it to rise and fall relatively to the paper or the like on the drum Q. This arrangement also ensures the breaking up of a magnetic pull into several stages corresponding to the conducting and insulating areas which are included in the circuit. synchronisation is also ensured by arranging the circuit as shown so that the pull of the electro-magnetic device G on the arm L is simultaneous with the action of the electro-magnet F or F on the armature I and persists as long as the calling subscribers arm H is traversing one of the conducting portions of his drum P.

In Fig. 2 of the drawings there is shown diagrammatically a side view of the impulse transmitting mechanism shown in Fig. 1 and Fig. 3 shows diagrammatically a side view of the impulse recording mechanism. In the arrangement shown in-Fig. 1, the drums P and Q are adapted to be rotated by a toothed or ratchet wheel N disposed intermediate the ends of a rotary memher which incorporates the two drums. If desired, however, this arrangement may be replaced by one in which the two drums are adapted to be rotated by a toothed or ratchet wheel disposed at one end of one of the drums as is shown, for example, in Fig. 4, the arrangement being such that the ratchet wheel N is adapted to be rotated step by step by a pawl associated with the armature 4 of an electro-magnetically operable device 5. The latter may be connected in circuit with a flexible contact device 1 arrangedso that the lever H or L contacts with the contact deviceat the beginning or end of its swing and so energises the electro-magnetically operable device 5 to attract the armature 4 and to thus turn the ratchet wheel through one step.

Referring now to Fig. 5 of the accompanying drawings, it will be seen that the subscribers bell C is arranged in the usual ringing circuit and that a ringing tone circuit is provided across the lines A and B by the conductors IBI, I62, I63, I64 and I65. Included in said circuit, is the electromagnetically operable unit b adapted, when energised, to attract one end of the switch lever d pivoted at 8 and adapted when so attracted, to engage the contact e. The latter is connected by a conductor I2, which includes an A. C. relay E, with another contact I4 which is normally engaged by a switch lever I5I which is in turn, connected by a conductor I5 to the pivotal mounting I8 of an impulse recording mechanism which is similar in many respects to that described above in that it comprises a V-shaped or hair-pin like member pivotally mounted at I8 and having two arms H and L arranged for movement over the surfaces of two rotatably mounted drums P and Q. The recording arm L may be provided with a suitable member arranged so that, when an armature 20 is attracted by an electro-magnetic device G, the arm will be caused to move out of its normal plane of movement and the marker will be brought into contact with a sheet of paper or the like X carried by the drum Q.

The mechanism also includes a weighted lever .or pendulum W (which is preferably flexible or resilient) depending from the pivotal mounting I8 and arranged for movement with the V-shaped or hair-pin like member and the lower end of the pendulum is provided with an extension serving as a contact 24 for engagement with a switch member 25 which may conveniently consist of a disc or ring-like element provided with a circumferential cut-away portion or recess and suitably biassed so that one side of the cut-away portion bears against the extension of the pendulum. The biassing may be accomplished by suitably weighting the switch member or by mounting the same eccentrically or by other means. I'hrough the medium of the pendulum and its contact 24, the conductor I5 is electrically connected with one side of the said cut-away portion which is con nected by a conductor 26 with an electro-magnetic device F and the latter is connected with the other side of the line B.

Hence, it will be seen that upon contact being established between the switch lever d and the contact e, a circuit is completed throughthe conductor 30, switch lever d, A. C. relay E, switch lever F, pendulum W and electro-magnet F to the line B and current traversing this circuit will energise the electro-magnet F thereby attracting its armature I50. The latter is pivoted at I8 and interconnected with the hair-pin like member so that the arm L is swung to one side of the sheet of paper X ready for operation.

It will also be observed that fromthe contact 6 is arranged a circuit parallelling that containing the A. C. relay E, the switch lever I5I and the conductor I5, said circuit including a switch 34 adapted to be closed by the relay E, a relay 35 for opening the switch I5I and the electro-magnetic device G. Hence, when an alternating or pulsating current derived from the exchange or senders apparatus traverses the circuit containing the A. C. relay E, the latter will be actuated to close the switch 34 and the marker will be brought into its marking position. Also, by virtue of the energisation of the relay 35, the switch I5I will be actuated to open the direct current circuit through F.

Each subscriber is provided with an impulse generating device for formulating impulses which are characteristic of his telephone number or other signal to be transmitted and this device may comprise a drum P provided with a central continuous conducting strip or ring and with two end continuous conducting strips or rings 4| and the intermediate portions may be formed with conducting and insulating areas or strips which are so arranged that, by the movement of the arm H thereacross in synchronism with the movement of called subscribers' recording arm L, impulses which are characteristic of the senders telephone number and exchange lettering or other signal to be transmitted are formulated. Intermittent movement of the drums P and Q is adapted to be brought about by a pawl and ratchet wheel N or other suitable means such as isdescribed above through the actuation of the electro-magnetically operable device 5 brought into operation at the end of each swing of the marking arm L. When impulses are to be transmitted over the line, the switch lever d is moved by automatic or manually operable means so that its upper end is brought into contact with the contact 46 which is connected with the drum P through an A. C. relay 48.

From the foregoing it will be seen that when the lower end of the switch arm d at the called subscribers station is in contact with the contact e, a D. C. circuit is closed through the switch I5I and the electro-magnet F. The current for this circuit may be derived from the central exchange or from a local source or battery adapted to be brought into operation by an exchange current and when this current is available and utilised for the actuation of the magnets F and the consequent displacement of the hair-pin like members, the pendulums W Will also be displaced in opposition to the .biassing means associated with the switches 25 and the arm H will be moved from contact with the conducting zones 40. The momentum of the pendulum device is sufficient, however, to carry the calling subscribers arm H over the nonconducting area to contact with the next conducting area formed, e. g. by one of the digits of the telephone number, with the result that the calling subscriber's mechanism formulates impulses varying in character with the nature of the telephone number, which impulses intermittently actuate the device G at the called subscribers instrument for efiecting the recording. Thus the circuits including the relays E and 35 will come into operation alternately as the calling subscribers arm H is advanced across the impulse formulating drum. In this way, the switches 25 are eventually brought into a position in which the biassing means causes the contact 24 to be broken and the opposite side of the recess of the switch contacts with the pendulum device to bring the other electro-magnet F into operation with the result that movement of the hairpin like members and the pendulum device will be reversed. In the arrangement illustrated, an armature 5| is attached to the recording arm L and 52 is a contact carried by the switch 25 for engagement with a relatively fixed stop and contact 53. When the contact 24 has swung its full period to the right the electromagnetic unit 5 operates to hold the armature 5| in position also the member 55 carrying the pawl associated with the ratchet wheel N. Also, when the calling subscribers arm H reaches the corresponding position the contacts 24. and 52 and the contacts 52 and 53 on his instrument will make and/or break and thus send across the inductive coupling a pulsation to operate the relay E at the called subscribers instrument. The relay 35 is thus brought into operation to open the circuit i5, 55, f 54, 53' and to de-energise the unit 5 to release armature 51 to enable the hair-pin like member to swing back and also to release armature 4 to rotate the drum Q. If the calling subscribers arm H arrives first and is held, through its arma- 173 ture 5| by its electro-magnet 5 the subsequent arrival of the called subscribers arm L andthe make and/or break operations will send back its pulsation to be received by the caller, via conductor 3i), 8, 45, 48 opening 58 and thus restoring electromagnet 5 and securing synchronism for the rotation of the drum.

It will be observed that when the electromagnetic unit b is actuated to cause the switch lever 01 to engage with the contact 6, it has the same effect for completing subscribers loop as if the receiver had been lifted and this flashes a signal to the exchange to connect the two subscribers in the usual way. On completion or" the message, the relatively conducting and insulating areas will flash the clearing signal.

The invention can be adapted to various forms of transmission lines or circuits whether wired, inductively coupled or radio-linked, the number, position and character of the various electrical units, e. g. inductances, relays, capacities and the like, incorporated in the system being varied to suit the individual requirements. For example, in order to carry into effect some of the objects of theinvention, -e. g. the transmission reception .40 and/or recording of electrical impulses, when the operator is not available, over a metallic and/or an inductively coupled line or circuit including radio-linked means of communication, the switch lever 34 may be arranged so that it is A5 normally in engagement with its contact, and

the switch lever I5| may be arranged to be normally free from its contact M (as is shown, for example, in Fig. 6 of the accompanying drawings) With such an arrangement when the bell 50 (or other warning device) current or impulse operates the relay 1) battery current will fiow from the line A, through 30, b, 8, d, e, 34, 35, G

and back via the B line. The relay 35 will then operate the switch lever l5l and battery current 55 will-flow through e, 12, E, [4, HM, I5, l5, W,24, 25,

F and back via the B line, both F and G functioning.

Now, if the partsH and P of the calling device are in metallic circuit, every time the part H 60 breaks circuit in the calling device, the devices G and F restore in the called device.

But when the two devices are inductively coupled then the interruptions of contact through H and P in the calling device are received as ($5 pulsations, or alternating current impulses by E, which opens 34, restores 35, opens l5! and both F and G at the called end restore.

Thus'the lateral movements of the respective hair-pin members are synchronised and the 70 sendersmakes and breaks are registered by the called subscribers device in the proper order.

As shown in Fig. 6, for synchronising the rotarymovements of the drums, or the sliding and the like movements of any of the other displacea'ble 75 elementsyin botha metallic and a non-metallic circuit, the electro-magnetic device 48 in the caling device may be aD.C.magnet and be connected through a normally closed switch lever 53 to the drum P. The device 48 controls a normally open switch lever 58 in circuit with an A. C. relay controlling the switch lever 65. Also, 53 may be a flexible or a relatively movable contact, and 4! may be a relatively large conducting area. Thus, in the calling device, the upper part of arm (1. having contacted with 46, D. C, current operates F then F, until 24 contacts 52 and 53 being movable or otherwise, offering a means of relative long contact battery current will flow from the A line through 8, 46, 48, 6B, 4!], 41, H, l8, W, 24, 52, and F to the B line. At the same time, battery current will also flow through 45,58, BI, 57, 55, 54, 53, 52, F, B line, B line in the called device, F, 52, 53, (if 52 has already arrived to contact with 53) 54, 51, 56, I5, I5l, E, l2, 6, d, 8, b and 35 to A line. The electromagnetic device 5 then operates to hold 4 and/or 5|, until W swings back and breaks and/or reverses the contacts. If 52 reaches 53 in one device in advance of the other, 5 cannot operate but a period of waiting is provided for, by 4| H in the calling device and 52 and 53 in the called device.

When the devices are coupled inductively or radio-linked then when 52 reaches 53 in either device 5 will hold 5|, and 4 until a make and/or a break pulsation is received from the other device to operate in the calling device 51 open 60 restore 48 and open 58 thus restoring 5 and in the receiving device the pulsation operates E opening 34, restoring 35 and opening [5| thus, too, restoring 5, the pulsations operating both ways.

In the above arrangements, the unit b may comprise an A. C. and/or a D. C. relay suitable both for causing d to engage with its proper contact and to hold the same engaged. Also, in some instances, a photo-cell or similar device may be provided for the purpose of engaging d and its associated contact.

Means may also be provided for marking or recording incoming and/or outgoing calls. For example, the G unit and 35 may be connected with a contact that is brought into circuit only when the arm H and/or the arm L or other movable element reaches that contact.

Means may also be provided for registering only the effective calls, whether incoming or outgoing, irrespective of whether the device is in use at the other end or not. lead may be taken from G and 35 to a contact disposed between 52 and 53 and this contact arranged to be brought into the circuit only when 52 is caused to engage with 53.

Also, the recording drum or sheet X may be provided with number graduations to facilitate the reading of the registration or checking marks. If desired, an alarm signal or warning mark may be associated with X or elsewhere for indicating or warning of the approach of a condition in which the marking means needs attention.

In its preferred form, the invention also includes means for enabling a calling subscriber to determine or be advised as to whether the correct number has been obtained and said means may be actuated or adapted to be brought into actuation by mechanical or electrical means. For this purpose, each of the drums P may be arranged so that it is capable of being adjusted angularly and each drum may carry a cam or othermeans capable of establishing contact at 45 and breaking the contact between (1 and e For the purpose, 2.

once the unit b has brought d and the cam within reach of one another. Thus, when the calling subscriber lifts his receiver and obtains a number, he will be able to hear the clicking sounds or notes produced by the functioning of the called subscribers device and on the approach of the signalling section of the device (which may be preceded by special interruptions on the drum) he can switch-in his device (if necessary after 10 adjustment) to have the called number marked on his recording element X. If this number should be the wrong one he then may have it cancelled in the usual manner.

Referring now to Fig. 'lof the accompanying 15 drawings, it will be seen that the subscriber's bell C is arranged in the usual ringing circuit and that the subscriber's circuit includes a device 200 incorporating sensitive pivotally mounted pointer or', switch 205 which normally rests against a 20 relatively fixed contact 20! and which, upon displacement, is adapted to engage another relativey fixed contact 202, the pivot being connected with one side (e. g. the side A) of the transmission line. Associated with the device 200 are an ear piece 206 and a microphone 201, the latter being arranged in close proximity to the former and being connected in circuit so that pulsations received by the ear piece will affect the microphone to cause the latter to influence the device 30 200 in such a manner that the pointer or switch 205 will be caused to be displaced from the contact 20l, towards or to the contact 202, such movements being in sympathy with or forming a reproduction of impulses received over the line. If desired, a battery 89 or other source of local current may be arranged in circuit with the device 200 or the apparatus.

In one side (e. g. the side 3) of the line is arranged the coil of a slow release relay b 40 adapted, when energised, to displace the switch member (1 pivoted at 8, said member in this embodiment comprising three arms indicated at d,

dl and d2.

The subsoribers station also includes an im- 45 pulse recording mechanism which is similar in many respects to those described above and comprises a V-shaped or hair-pin like member pivotally mounted at l8 and having two arms H and L arranged for movement over the surfaces 0. of two rotatably mounted drums P and Q. The

recording arm L may be provided with an armamm 20 opposite which is disposed an electromagnetic device G which when energised will cause the arm to move out of its normal plane 55 of movement so that a marker M or the like provided at the end of the arm will be brought into contact with a sheet of paper or the like X.

carried by the drum Q. The electromagnetic device G is preferably carried by means also 60 pivotally mounted at l8 and adapted to move about the pivot in synchronism with the arm L. As will hereinafter appear, the arm L is adapted tobe moved about the pivot l8 to cause the marker or the like to move across the paper 65 X and the arrangement is preferably such that the arm is displaced in one direction (e. g. to the right) by the actuation of an electro-magnet F when it attracts an armature I50 carried by the aforesaid V-shaped or hair-pin like member and 70 is adapted to be displaced in the opposite direction under the influence of gravity. During the periods when the arm is required to be moved by gravity, it may be desirable to provide means for arresting its movement about the pivot l8 whilst 75 the marker is in contact with the paper and, for

this purpose, there may be provided adjacent the opposite end of the electro-magnetic device G which end may be slow to release, alfixed but flexible metallic member adapted, upon energisation of G, to be attracted andflexed by G in such 5 a manner that both G and the arm L will be momentarily prevented from movement about the pivot l8.

The aforesaid drum P forms part of an impulse generating device for formulating impulses 10 which are characteristic of a telephone number or other signal as is described above, the said drum is provided with conducting and insulating areas or strips which are so arranged, that by the movement of the arm Hthereacross in synchronism with the movement of called subscribers recording arm L, impulses which are characteristic of the senders telephone number and exchange lettering or other signal to be transmitted are formulated.

Synchronism of the respective markings at one end of the line with the corresponding impulses generated at the other end is brought about by the functioning of the respective relays and their associated contacts, and the consequent functioning of arresting means for the arms H and L as hereinbefore described. Intermittent movement of the drums P and Q is adapted to be brought about by the pawl and ratchet wheel N or other suitable means such as is described above through the actuation of the electro-magnetically operable device 5 brought into operation at the end of each swing or during the swing in either direction of the marking arm L. When impulses are to be transmitted over the line by 30 the calling subscriber, the switch lever d3 is moved by automatic or manually operable means so that its lower end is brought into contact with the upper end of the lever dl, and dl swings so that d is contacted with 46 or c.

It will be seen that, when a subscriber is called, alternating current can pass from one side of the line, e. g. A through the bell or other warning device C, capacity C and the coil of the slow release relay 1) to the other side of the line.

The effect of such a ringing current through b is to cause the switch lever dl to be swung about the pivot 8 to the left and also to close the switch 4. Closing of switch 204 by-passes b and allows the bell to ring without deleterious effect. 50 Also, by the movement of dl,the lever d will be raised to engage either a contact e or a cam 40 carried by the shaft carrying the aforesaid drums. When the lever d contacts with the contact 6 or with the cam 46, the circuit is completed through conductor 15, contact strips 82 and 83, arm H, plate 225, and the coil of the electro-magnet F" to the other side of the line, thus providing a path for alternating current or pulsations.

The ringing current is now capable of influencing device 200 and its sensitive element 205, which will move to contact 202, and a solenoid E will operate closing by-pass switch 86 to form a path for D. C. and thus trip the ringing current circuit. (E may be of an inductance and/or resistance that will allow ringing current to continue functioning.) The calling subscribers can now hear the called station apparatus function and may operate his switch d3 to start his apparatus and receive and/or transmit signals. Solenoid E may also be slow to operate and thus switch element 205 may have to be moved to 202 more than once to close 86. Alternatively, it may be arranged, e. g. in metallic circuits, for the ringing current to continue until the calling sub- 40 the line.

scriber realising that the called subscriber is not answering operates his impulse transmitter or closes his switch (13 to bring his transmitting apparatus into operation. By the act of switching at the calling subscribers end of the line, the ear piece 295 and microphone 281 at the called subscribers station as well as those at the calling station if so equipped will be brought into operation so that the sensitive pointer or switch element .205 will be momentarily swung into contact with the contact 202 to close direct current circuit from one side of the line (e. g. A), through 255, contact 252, a slow release solenoid E, conductor 9!, electromagnetic device G and conductor 92 to the other side of the line. Thus the solenoid E is brought into operation to hold the levers d2 andd tilted with the latter in contact with as or s. Also, by the operation of E, switch 85 is actuated to by-pass condenser 85 at the called station and thus closing another D. C. circuit and by the operation of G, the armature 29 is attracted to cause the marker M to be brought into contact with the paper X. Having thus set up the D. C. circuits referred to and as soon as switch element 205 returns to contact with 251, the direct current passing through E" operates the latter to cause H and L to swing to the right about the pivot Hi, the swinging movement continuing until L reaches its other extreme position.

Shortly before the marking arm L reaches the end of its swinging movement to the right, contact takes place between an element 52 carried by the arm, a switch 58 and a contact 53 with the result that the circuit is closed from A through M5, 25!, switch 85, lever d, conductors l2 and i5, conductor 56, coil 54 of the electromagnetic device 5, contact 53, switch 58, coil of the electro-magnetic device 19 to the other side of Electro-magnetic device is thus operated and attracts the armature 5| on the arm L and is at this stage of the operation in close proximity to the device 5. Also, the downwardly extending portion of the electro-magnetic de- 45 vice 5 attracts the armature 4 which is provided with a one way flexible pawl engaging the ratchet wheel N so that the latter becomes turned through one step. In the meantime the arm H has separated from the contact device 25 and discon- 50 nected contact strips 82 and 83. At this stage, whether the senders arm L has already reached a corresponding position at the other end of the line or is still lagging the hair pin like member arriving first will be held waiting by the direct current solenoid until the slow acting electromagnetic device l3 operates to close the switch 18 and the impulse thus produced at both or first at one then at the other end causes. the element 205 to be displaced and to break the circuit at 25!. Thus the commencement, the stepby-step movements during, and/or the ending of each swing, and the angular displacement of the drum, are synchronised. The switch 25 is nex ibly mounted so that the part thereof which carries the contact strips .82 and 83 is slightly inclined to the plane of oscillation and a bent L- shaped projection carried by the arm H is able to contact with the contact strips 82, '83 on one side of the switch 25 when the hair-pin like-mem- 70 her is moved to the right and with the contact strip 25 on the other side of the switch 25 when falling back under the action of gravity to the commencing position] Thus, when the hair-pin like-member released by the electro-magnetic de- 75 vice 5 is falling back, the arm H engaging with the drum P closes a circuit from one side of the line e. g. A through 255, 2!, conductor 30, switch '86, drum P, arm H, contact 28 on the underside of 25 and back to the other side of the line. As mentioned above, the surface of the drum P is made up of insulating and conducting areas preferably flush with one another and with the rest of the drum, according to the outline of the signal to be transmitted and as the arm H passes from a conducting to an insulating portion and vice Versa, impulses are formulated, said impulses actuating at the senders and/or the receivers end the relay comprising the ear piece and microphone device and th device incorporating the pointer 0 so that in turn the pointer 205 is caused to move and contact With the contact 262 which again enables a current to operate the electro-magnetic device G and to cause the markings to be produced upon the paper X. In this manner, X receives a series of markings corresponding in position from right to left with the position of the respective insulating and/or conducting areas provided on the senders drum P, which are continued in succemive lines with the step by step rotation of the respective drums. Shortly before the hair pin like member reaches the end of its movement to the left, the solenoid 93 will be operated to raisethe armature 32 which is now in proximity to the solenoid, to cause the contact to be broken at 25 and to dis place the arm H beyond its normal position. When, however, solenoid 93 restores and permits the arm H to be restored to its former'position of contact with strips 82 and 83 arm H will again serve to close the circuit through the electromagnetic device F.l. If desired, the paper X may rest on a support so that the marker M is at a constant distance from X for ensuring the effective striking of the same irrespective of any variations in the diameter of the roll of paper.

- It will be appreciated that the device incorporating the switch element 2B5 and the contacts and 202 may comprise one or more rigid or flexible contacts for making and/or breaking and/or by-passing circuits. Also, more. than one switch element 255 may, in some instances, be provided and arranged so that each functions under different conditions. For example, one such element may be provided and arranged so that it normally contacts with 20! when the bellis ringing and moving to contact 2B2 with the variations of the bell current and another such pointer may be provided and arranged so that it normally contacts with the contact and moving to contact with its contact 262 with the formulation and reception of the signals after the bell has stopped ringing.

In Fig. 8 of the accompanying drawings there is shown a circuit arrangement which is similar in many respects to that shown in Fig. '7 and in which corresponding elements are denoted by corresponding references. In this arrangement, however, there is introduced a delay-action means adapted to afford the called subscriber when he is available, the opportunity of; or a" longer period for, answering the call before the recording mechanism is: brought into operation. Also, the said means may'afford the calling subscriber the opportunity of hanging up his receiver before the termination of the ringing period. For the purpose of introducing such a delay a plurality of switches or oscillatory members is used and arranged so that for a period they operate in out-of-phase :relationship and only when the said switches 'or oscillatory -members become in phase or otherwise coincide or co-operate will the circuit for initiating the operation of the recording means be completed. For example, the device 200 may be provided with a further contact 2I0 arranged so as to be engaged by the switch element 205 at the time the latter contacts with the contact 202. Also, across the contacts 2I0 and 202 is arranged a circuit including a local battery I00 and an electromagnetically operable device 94 which, when actuated is adapted to attract one end 99 of a lever or pendulum device 91 mounted for movement about a pivot 95, the lower end of the said device being provided with a contact I03 for engagement with another contact 96 connected with the slow release solenoid E. The lever or pendulum device is preferably provided with an adjustable or displaceable weight 9'! so that its period of oscillation relatively to that of another switch, pointer or lever, e. g. the element 205, can be varied. Thus, when the ringing or warning bell C is actuated, the element 205 will be swung into contact with the contacts 2| 0 and 202 and local circuit through contact 2I0, battery I00, device 94 and other contact 202 will be completed, with the result that the electro-magnetic device 94 will be brought into operation to attract the upper end 99 of the lever or pendulum 91. The lower end I03 of the lever or pendulum is thus caused to engage with the contact 06 which is connected with the slow release relay E for establishing a circuit through E, 8, d, e, I5, 82, H, 83, 93 and the line B. It will be seen that the pivot 95 of the lever or pendulum 91 is interconnected with the contact 202 and that it is not until the contacting of 202 and 205 coincides with the contacting of I03 and 96 that the relay E will be brought into operation to close the switches 86 and 98 for establishing the ap- 0. propriate D. C. circuits. Hence, by suitably varying the difference between the period of oscillation of the element 205 and that of the lever or pendulum device 97, the delay period can be increased or decreased. It will also be seen that,

45 in this arrangement, inter-action between the microphone 201 and the ear piece 1 is increased by the inclusion of an inductive coupling or transformer I08.

Having thus described this invention what I claim as new therein and desire to secure by Letters Patent is:

1. A telephone system having a plurality of subscribers stations each equipped with means for formulating and transmitting over the line impulses constituting a recordable signal and recording means arranged to be brought into operation at a called subscribers station for receiving and recording the signal of the calling subscriber, the said impulse formulating means and recording means comprising a double-armed member constituting an impulsing arm and a recording arm arranged for movement over the surfaces of a pair of rotatably mounted drums, one of the said drums being formed with conducting and insulating areas contoured and arranged for scanning by the impulsing arm to produce a predetermined signal and the other drum being equipped with a record element for cooperation with the recording arm, and the arrangement being such that by the relative displacement of the drums and the double-armed member, the impulsing arm at the calling subscribers station opens and closes the circuits for the transmission of the predetermined signal while the recording arm at the called subscribers station is moved across and to and from the record element at the latter station to record the impulses transmitted.

2. A telephone system as claimed in claim 1 provided with electro-magnetically operable means for effecting a step-by-step displacement of the double-armed members relatively to the drums at the calling and called subscribers stations.

3. A telephone system having a plurality of subscribers stations each equipped with means for formulating and transmitting over the line impulses constituting a recordable signal and recording means arranged to be brought into operation at a called subscribers station for receiving and recording the signal of the calling subscriber, the said impulse formulating means and record ng means comprising a double-armed member at each station, one arm of the doublearmed member forming an impulsing arm and the other arm forming a recording arm, each double-armed member being arranged for oscillatory movement relatively to the surfaces of a pair of drums, one of said drums being formed with conducting and insulating areas contoured according to the characteristics of the signal to be transmitted and the other drum being equipped with a recording element with which the recording arm cooperates, and electro-magnetically operable means for imparting step-by-step rotary movements to the drums at the end of each swing of the double-armed members.

i. A telephone system having subscribers instruments equipped with means for formulating and transmitting over the line impulses constituting a recordable signal, which signal is characteristic of the telephone number of the calling subscriber, and recording devices arranged to be brought into operation during the absence of a called subscriber for receiving and recording the signal of a calling subscriber, the said impulse formulating means comprising a contact member movable in relation to a displaceable element and the said displaceable element having parts of differing electrical characteristics contoured according to the nature of the signal to be transmitted, said subscribers instruments being fitted with a sensitive pointer arranged in circuit with a receiver or ear piece disposed in close proximity with a microphone whereby pulsations received by the receiver affect the microphone to cause the pointer to move in sympathy with the impulses received for the purpose of setting up the circuits required for recording such impulses.

5. A telephone system having a plurality of subscribers stations each equipped with means for formulating and transmitting over the line impulses constituting a. recordable signal, the said impulse formulating means consisting of a contact member movable in relation to an angularly displaceable drum and the said drum being made up of relatively conducting and non-conducting areas contoured according to the nature of the signal to be transmitted, and recording devices arranged to be brought into operation at a called subscriber's station for receiving and recording the signal of the calling subscriber, said subscribers stations each being fitted with a sensitive pointer, a receiver or ear-piece arranged in circuit with the sensitive pointer and a microphone disposed in close proximity with the receiver or ear piece whereby impulses received by the receiver affect the microphone to cause the pointer to move in sympathy with the impulses received for the purpose of setting up the circuits required for recording said impulses.

6. A telephone system as claimed in claim provided with a delay action means for introducing a delay in the setting up of the signal transmitting and receiving circuits.

7. A telephone system as claimed in claim 5 provided with a delay action means consisting of a plurality of oscillatory members arranged to control the closing of the signal transmitting and receiving circuits, the arrangement being such that only when the said members are in phase will the circuits for initiating the actuation of the signal transmitting and receiving means be completed.

8. A telephone system having a plurality of subscribers stations each equipped with means for formulating and transmitting over the line impulses constituting a recordable signal, the said impulse formulating means consisting of a scanning device movable in relation to an 'angularly displaceable drum and the said drum being made up of relatively conducting and non-conducting areas contoured according to the nature of the signal to be transmitted, and recording devices arranged to be brought into operation at 2. called subscribers station for receiving and recording the signal of the calling subscriber.

9. In a telephone system, a calling station including means for formulating and transmitting electrical impulses, said impulse-formulating means comprising a scanning device including a contact member, an angularly displaceable drum having on its surface a signal outline, said signal outline being made up of relatively conducting and non-conducting areas contoured according to the nature of thesignal to be transmitted, means for causing the contact member to traverse the surface of the drum whereby each point on the surface of the drum is brought into drumhaving on its surface a signal outline made up of relatively conducting and non-conducting areas'contoured according to the nature of the signal to be-transmitted, means. for moving said contact member back and forth over the surface of the drum, means for rotating said drum to bring each point of its surface in turn beneath the contact member, means for transmitting over the line point-by-point impulses produced by contacts sequentially established between the contact member and the conducting parts of the signal outline, and a called station including means for sequentiallyrecording said impulses to re-formulate point-by-point the signal outline.

GEORGE MICHAELSON.

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