US2491205A - Call recording system - Google Patents

Description

Dec. 13, 1949 M. POTTS 2,491,205

CALL RECORDING SYSTEM Filed Dec. 28, 1945 4 Sheets-Sheet 1 INVENTOR LOUIS M. POTTS DECEASED '{MRTHA W.C. POTTS, EXECUTRIX BY J WM ATTORNEY L- M. POTTS CALL RECORDING SYSTEM Dec, 13, 1949 Filed Dec. 28, 1945 4 Sheets-Sheet 4 LOUIS M. POTTS DECEASED MARTHA w.c.POT1's, axscu'rmx INVENTOR ATTORNEY Patented Dec. 13, 1949 Louis M. Potts, deceased, late of .Evanston, IlL, by Martha W. C. Potts, exec'u'trix, Evanston, Ill., ass'ignor .to Teletype Corporation, Chicago, 111., a corporation 'o'f Delawa re' Application December 28, 1945,.- SeriaLN 0. 637,650

13 Claims. 1

The present invention relates to telephone systems and more particularly to call recording apparatus and circuits for use therein.

Apparatus and circuits have previously been devised for use in call recording or recording a calling subscriber's number at a called subscribers station when the latter is absent and/or fails to answer the telephone. However, such solutions utilize very complicated apparatus order to achieve the desired results;

Accordingly, the main object of this invention is to provide simplified apparatus-and circuits .ior generating and recording 'a calling subscriberfs number at an absent called subscribersstation.

A further object of the invention is to provide such apparatus and circuits which will operate automatically after a predetermined number of bell rings have gone unanswered.

Still another object or the invention isthe provision of a special operator's station to which may I be transmitted a message to be left at the absent called subscribers station and which will be transmitted and recorded thereat under the control of the leave word operator.

A still further object of the invention includes apparatus whereby the calling subscriber s number will not be recorded at the absent called subscribers station until the former concludes his attempted call and replaces his phone to a normal unoperated condition.

The features and advantages of the invention will become apparent from the following detailed description of specific embodiments thereof, when read in conjunction with the accompanyingdrawings, in which:

Figs. 1, 2, and 3 illustrate a telephone system incorporating therein call recording apparatus and circuits, and should be Viewed together from left to right, respectively;

Fig. 4 is a view similar to Fig. 1 but incorporating apparatus whereby the call recording will not occur until the calling subscriber has replaced his station apparatus to an unopera'ted condition, and should be viewed with Figs. 2 and 3, and

Fig. 5 shows a leave word operators-station.

The following description will only refer to so much of the telephone system asis necessary for a complete understanding of the invention. The telephone system utilizedis oi the: panel dialtype, is standard, and is well known to those versed in the art.

Referring to Figs. 1 to 3,:inclusive, Fig. 1 shows a calling subscribers station .A and lines H conncc'ted through a line finder' district l2 to'an-oflice selector 13, which is-con-nected through an in-. coming selector circuit I4, Fig. 2; a final selector [5, Figs. 2 and '3, and over the lines ll to a called subscribers stationB. The line finder and selectors are of the panel type and may be similar to the construction and operation of the switches disclosed in United States Patent 1,123,696, issued to Craft .et al. on January 5, 1915.

In the following description an assumption will be made that the calling .subscribers station A has been dialled in accordance with the call numbers of the called subscribers station B and that the .line finder district 12, the ofiice selector it, the incoming selector circuit TM and the final selector 16 have operated in accordance will the usual panel dial telephone circuit operation to connect the calling station A with the called station B and condition a talking circuit which will be established by the subscriber at station B removing the receiver.

Such a connecting circuit may be traced over the lines H from the calling subscribers station A to tip and ring connections 13 and I9, respectively. Further, the circuit may be traced from grounded batteryi I through the left-hand winding of a repeater coil 2-2, through the Winding of a relay '23 and over conductor 24 to the ring connection l9 and thus to one-side-of line I]. The completed circuit may :be .further traced 'from the other side of line -I I, through the tip connection l8,over a conductor 26, and through the lefthand winding of a repeater :coil 21 to ground at 2 8.

Further tracing of the circuit, through the line finder district :I 2 may be made from the induced current in the right-hand winding of the repeater coil 21, through sequence switch cam 29 which will form a closed path at this time, over aconductor 34 to a connector 32 in the ofiice selector I3. The other half or side of the circuit may be traced from the right-hand winding of repeater coil 2-2, over a :conductor 33, through thesequence switch cam 34 which forms a closed path at this time and over conductor-3t toeonnector 31 in the oiiice selector 13; v

The upper half of the circuit tromconnector 32 in the "office selector t3 may be traced to the incoming selector circuit l4 over conductor 8, through sequence switch cam 39. which forms a closed. path at this time, through the left-hand winding of a repeater coil ill -lover a conductor 42, through an armature 43 of arelay M which is in its unoperat-ed or left-hand position, and through aeonductor cc and the left-hand winding of'a relay l! to grounded battery-48. The opposite side of the circuit may be traced from the connector 31 in the ofilce selector, over conductor 49 to the incoming selector circuit M, through the sequence switch cam 59 which will be in position to form a closed path at this time, over conductor 52, through the left-hand winding of a repeater coil 53, over a conductor 54, over a conductor 56, and through the right-hand winding of the relay 4? to ground at 51.

The circuit from the incoming selector circuit It to the final selector I6 will result through induced circuit occurring in the right-hand windings of the repeater coils H and 53. Such circuit may be traced from ground, through the right-hand winding of repeater coil 41, through a sequence switch cam 58 which forms a closed path at this time, over a conductor 59, through an armature 61 of a relay 62 which is in its unoperated condition at this time, and over a conductor 63 to a connector 64 associated with the final selector circuit it. The opposite half or side of the circuit may be traced from grounded battery 66, through the right-hand winding of the repeater coil 53, over a conductor 67, through the winding of a relay 68, through a sequence switch cam 69 which will be closed at this time, over a conductor H, through an armature 12 of the relay 62 which is in its downward or unoperated condition, and over a conductor 73 to a connector 14 associated with the final selector I6. The connectors 64 and 14 are connected by means of the lines I! to the called subscribers station B.

The circuit just described is conditioned only, and will be fully established upon the called subscriber answering his phone. The relay 23 at the line finder district l2 will be energized as the calling subscriber at station A has his receiver removed, but the relay 88 in the incoming selector l4 will not be energized as the receiver at station B has not been removed.

Upon the conditioning of the circuit described above a machine ringing relay 15 will be energized, in a manner well known in standard telephone practice, to cause the bell to ring at the called subscribers station B indicating a telephone call. The relay 15 remains energized until such time as the called subscriber answers his phone, at which time superposed direct current prevents further operation. As a result of the energization of the relay ringing current is applied through an alternating current relay 16 which has been added. Even though the relay 15 remains energized the relay 16 will be caused to operate only intermittently, as the alternating current is supplied at intervals, interspaced by periods of rest. In the event that the subscriber at station B removes his receiver, causing relay 15 to become de-energized, as previously mentioned, the relay 16 will no longer receive alternating current and will remain tie-energized.

However, in the event that no one is present at the called subscribers station B or for some other reason the receiver is not removed from the hook, the telephone thereat would continue to ring until such time as th calling subscriber A discontinued the call and the telephone circuit selecting apparatus automatically broke the circult. In the present invention means are provided whereby in the event that there is no re sponse at the called subscribers station 13 after a predetermined number of bell rings, an apparatus will be operated to record the calling subscribers number at the called subscribers station. Such apparatus will now be described.

With reference to Fig. 1, a signal generating apparatus 11 is provided which would be located at the central telephone station but which will generate numbers indicative of the subscriber's stations associated with such central station. The signal generator 11 includes a pair of distributor rings such as the segmented ring 18 and the solid ring 19 which are traversed by the brushes 8|. The segmented ring 18 is segmented in such a manner as to generate signals indicative of the station call letters of the calling station; that is, the identifying letters only. If in the following description it is assumed that the calling subscribers number is BUC 6200 the ring 18 would be segmented in accordance with the letters BUC.

It might be well to point out at this time that the telegraph signals which are transmitted through the switching equipment are modulated alternating current of a suitable audible frequency. These signals are of this character so that they can be transmitted through condensers when required and are adapted to pass through the various link circuits commonly used in telephone service. The signals are later converted to direct current signals, as will be described, suitable for operating a monopulse printer of the type and in the manner disclosed and described in U. 8. Patent No. 2,147,075, issued to W. J. Zenner on February 14, 1939. Such printer is by way of example only, as signals for operating permutation or other types of printers may be generated in a similar manner. According to the embodiment shown, wherein the printer disclosed in the Zenner patent is contemplated, the pattern of segmentation of ring 18 is such that each interval represented by the numeric I00 is equal to an isochronous code signal interval as shown in Fig. 1 of said Zenner patent.

The signal generator 11 is further provided with two sets of rings such as the segmented ring 82, solid ring 83, and segmented ring 84 traversed by the brushes 86 and the segmented ring 81, the solid ring 88 and the segmented ring 89 traversed by the brushes 9|. The segmented ring 82 is segmented in such a manner as to transmit telegraph signals indicative of the thousands and hundreds components of the telephone number, such as 6 and 2 in the instant example. Likewise, the segmented ring 81 is segmented in such a manner as to transmit the tens and units components of the number, such as 00 in the instant example.

It will be understood that it is necessary to provide one-hundred each of the rings 82 and 81 in order that complete numbers from 00 to 99 may be transmitted in accordance with each telephone subscriber. However, in view of the fact that it would be mere repetition to include such a multiplicity of distributors in the instant drawings and would serve no useful purpose, one only of each of such rings have been illustrated. Only one station call letter distributor 18 need be included.

The generated signals, caused by the brushes traversing their respective rings, originate with an alternating current generator 92 and pass over a common conductor 93 to a conductor 94 leading to the segmented ring 18, a conductor 96 leading to the segmented ring 82, and a conductor 9'! leading to the segmented ring 81.

The segmented ring 18 is provided with a start segment 98 which must be of a length appreciably longer than the time required for a complete monopulse signal to be transmitted, insulated segments 99 and signalling segments l0! which are indicatlvedn monopulsecod'e; of thel'etters- BUG; as previously mentioned. The codese ments: Iill are insulated. from each otherand from the-start: segment 98 bymeans of the insulated. segments" 99. The brushes 81-, 86, and iii are continuously traversing;theirassociated rings and. thus a circuit may betracedflfrom alternating current generator Q2", over the" common conductor 93, overthe conductor 94,.throughthe start segment 98; over brush 81' asit traverses thestart segment; through the solid distributor ring 19 and over a conductor 192.; from conductor m2 may be traced" through sequence switch cam I93 which forms" a closed path upon. the completion of the telephone circuit, over a conductor. its having; a condenser therein, through an armature IE6 associated with a relay Ill? but which is, in its unoperated or leftward. position, and over a conductor N38 to the conductor 2% previously described, which forms part of the ring circuit. As the brush 8! further traverses the segmented ring I8 it will pass over the code segments NH and cause signals to be impressed on the conductor 24, over the circuit just. described.

As previously mentioned, the segmented ring 82 was providedwith code segments indicative of the thousands and hundreds components of the calling subscribers number. which are indicated by the. numeral. I99 and v which are separated by meansof. insulation I II.

Alsov as previously described, segmented ring 87 generates signals. indicative of the tens and units. components, such segments being indicated by the numeral I I2 and separated by the. insulation I53.

It should be noted that the s-egmentson thedistributor rings EB, 82', and 81. are so positioned that none of them occur at thesame time. Thus, as the. brushes GI, 35, and 9E traverse their respective rings, the, start signal wouldbe transmitted first, then the station call. let ters.(BUC), and flnally the call numbers (620(1) in such. a manner that they would fall in their. normal order.

At the-same time that the circuit is completed between the tWo stations and the, bell ringing,

occurs, a relay H4 is energized in. accordance with standard telephone practice. Upon the. energization of, the relay II lits armatures I It,

Ill, and III are. attracted. thereto, armatures lit and H8 serving to. disconnect theline relay lit from the. calling circuit, in .a, manner. well known in telephonepractice. The attraction of armature Iii will. cause it to engage, its. associated electrical contact i2I.

It might be noted that. the, relay us is comprised of three windings, the. center Winding causing the energization of therelay and the attraction of. the armatures, whereas. the purpose of the right-hand andleft-hand windings will become. apparent during the. following description.

The attraction of thearmature I l'Ijin engagement with the contact I2'I. closes electrical circuitsfor. the transmission. of. the numerals of the.

calling subscribers station in a manner which will now be described.

As the. brush 86 traverses thev segmented ring 82 and, particularly the code segments I 85-], an electrical circuit is completed. which may be traced from the alternating current generator 9:2, over the common conductor 93", 0ver. the con.- ductor st to the segments I09,over the traversing brush (it, through the solid distributor ring 33, over. a. cable or trunk. IZiZthrough resistor I23, through the winding of the right-hand coil of the The further" circuit relay M4; overaconductor I24 to contactpoint':

I E i, through the armature I I I attracted thereto;- through a resistor and l over acabl'e 01" trunk. I265 through the solidring 88, oven the traversing brush 9i, through the uninsul'ated segment-Riot the segmented ring 89',- and over" a: conductor I 28 to ground 5251 As may be-seen byreferencete the segmented ring 89'- the uninsulated portion I-2'-'I-thereof is-inalignment'with the section ofthe segmented ring 82 assigned to thethousands and hundreds components of" thecalling subscriber-s number, inasmuch as all the brushesrotate-together;

It should be'noted' that then-rwillbe'on'e hundred leads 9%, one for-ea'chpair of digits OO-to 99; t'orepresent thousandsand hundreds. It is also tobe noted that-there will be one-hundred 'leads H25 which-carry signals similar'to those'on leads t6 except that they represent tens and units: Apparatus is so provided that the-signals will be generated in proper time relation to-eachother, so that while'the thousands and hundreds signals: are generated thelea'ds I 2 6 Wi11' be-grounded, and vice versa. 33'' this arrangement the two'-- hundred leads servegto-give separate-number in dications to ten thousand difierent' numbered telephoneilinesz.

As the brushes further traverse theirrespective rings a circuit may be traced from alternating current generator-92, over the commonconduct'or 9.3, over the conductor'9'i; through'the code-seg-- ments H2 01"". the segmented ring 87, over the traversing brush" 91-, over the solid ring 88; overthe cable or trunk; E25 and the resistortherein, irough the armature- I-I-T- in engagement with contact I2 l, over the conductor I24, through the right hand" winding of the relay I Hi; through-the resistor I23, overthecabieontrunk I22; through the solid ring 33', overt-he traversing brush 86,

through the uninsulatedisegment I3I= ofthe segmented distributorring 8.4, and over a conductor 82 to ground I29. In. the present instance the uninsulated portion- I'BI of the segmented ring as. isaligned with the portion of the segmented ring 8? assigned to the tens and units components of the calling subscribers number.

The right-hand andleft-handwindings ofthe: relay II l. are. so constructed. that energization of the right-hand" winding; dueto' the code segments being traversed as: just. described, will cause a. similarenergization orialt'ernating cur rent to be induced in. the; left-hand winding thereof. As a resultof'such. occurrence the induced' signals in. the, left-hand winding are transmitted over. conductor. I'SS-Iea'ding;fromthe'lefthand coil to the sleeve terminal I,34, over a conductor hill, through thesequenceswitch. cam: I03 forming. a closed path; over: the conductor" I65, through the armature I06, over the conductor see, and. willthus beireimpressed on the telephone circuit. on the conductor. 24 of. the tip circuit.

Thereforeas the brushes 81,, 86,,and' SI traverse their associatedsegment's;which occurs continuously, alternating current signals will be 1mpressed' on. the conductor 24. in a manner as has. just been described for both call letters and numerals indicative of. the calling, subscriber's station. However, even thoughthisoccurs during. the time that the" bell; ringing. mechanism is operatingthe. added superimposed alternating, current will notiaffect'the.standarditelephone circuit in any way.

It might be. noted at this;t1me. that. in. the. event that'a called'subscriber answeredhis phone a relay I35 would energize according to standard telephone practice resulting in its armature I36 being attracted thereto and thus completing a circuit which may be traced from ground, through the armature I36 which is now in its attracted or right-hand position, over a conductor I31 to junction point I38, over a conductor I39, and through the winding of the relay I91 to grounded battery MI. The resultant energization of the relay I81, causing its armature I96 to be attracted thereto, would break the circuit previously traced from the conductors I92 and I49 and preclude further signals (BUC 6200) from being transmitted to the conductor 24. Therefore, under this condition no further signals indicative of the calling subscribers station would be transmitted to or be placed on the telephone circuit, thus allowing conversation to occur in its normal uninterrupted manner.

As was previously mentioned, the bell ringing mechanism causes the relay 16 to operate, thus causing it to be energized and de-energized successively in accordance with the necessary rings of the bell. As a result of the energization of the relay 16 it will cause its associated armature I42 to be attracted thereto which results in an electrical circuit being established which may be traced from grounded battery I43, through the armature I42 to a contact point I44 with which it is now in engagement, over a conductor I46 and through the winding of a magnet I41, over a conductor I48 to junction point I49, over a conductor II, through a sequence switch cam I52 which now forms a closed path condition, over a conductor I53 and through an armature I54 of relay 68, previously mentioned, to ground. As was also previously mentioned, inasmuch as the telephone circuit which was fully traced is not actually established until such time as the receiver is removed at the called station B, the relay 68 which forms part of the telephone path will not be energized and thus its armature I54 will be in an unoperated condition so as to allow the establishment of the circuit just traced. The magnet I41 will be energized and de-energized intermittently in accordance with a similar condition of the ringing relay 16.

The armature of the magnet I41 is formed of a lever I56 pivoted at I51 and normally urged in a clockwise direction by means of a spring I58. The lever I56 has pivotally connected thereto at I59 a pawl I6I which is normally urged in a counterclockwise direction by means of a spring I62 toward engagement with an associated ratchet I63. Counterclockwise motion of the pawl I6I is limited by means of a stop I64. The ratchet I63 is provided with a stop arm I66 associated therewith which is limited in its clockwise movement under urging of a coiled spring (not shown) by means of a stop I61 to return the ratchet I63 to its unoperated position.

Also associated with the ratchet I 63 is a detent I68 which is pivotally mounted and which has an extended portion I69 which forms the armature of a magnet I1I. The detent I68 is normally urged in a clockwise direction away from the ratchet I63 by means of a spring I12. However, during the time that the relay 68 is de-energized and the sequence switch cam I52 completes its circuit, an electrical circuit may be traced from ground, through the armature I54, through the conductor I53, through the sequence switch cam I52, over the conductor I5I' to junction point I49, over a conductor I13, and

8 through the winding of the magnet "I to grounded battery I14. The magnet I1I will thus become energized attracting its armature I69 thereto which results in the detent I68 being engaged in the teeth on the periphery of the ratchet I63 thereby preventing the ratchet from moving in a clockwise direction.

Each time that the armature I42 is attracted by the energization of the ringing relay 16, it engages contact I44 which results in the energization of the magnet I41. At such time the armature lever I56 will be attracted thereto, the pawl I6I will be moved upwardly in engagement with a tooth of the ratchet I63 and the ratchet will be turned in a counterclockwise direction a distance equal to the distance between successive teeth. The ratchet thus will be turned one tooths distance each time the telephone bell rings at the called subscribers station B.

As the ratchet I63 moves in a counterclockwise direction a predetermined distance, its stop arm I66 moving therewith will engage a movable swinger I16 causing it to pivot in a clockwise direction and engage its associated contact I11. At such occurrence, an electrical circuit is established which may be traced from grounded battery I18, through the contact I11, through the movable swinger I16, over a conductor I19, through a contact I8 I through a movable swinger forming part of a common member I82 which is in engagement therewith at this time, over a conductor I83 tojunction point I 84, over a conductor I 86 and through the winding of a relay I81 to ground. As a result of the completion of such electrical circuit the relay I81 will be energized and will remain in this condition inasmuch as the detent I66 will cause the electrical swing I16 to remain in contact with its associated contact point I11 through its action on the rachet I63 until such time as the magnet I1I may become de-energized. Such magnet however does not become de-energized until such time as either the relay 68 becomes energized or the sequence switch cam I52 opens a circuit, which will not occur until the called subscriber removes his receiver from the hook or the calling subscriber abandons the phone call, respectively.

Upon energization of the relay I81 and the resultant attraction of its armatures I88 and !89 thereto, two electrical circuits are established, which will now be traced. One such electrical circuit may be traced from ground, over a conductor I9I, through the armature I88, over a conductor I92, and through the winding of a magnet I93 to grounded battery I94. The resultant energization of the magnet I93 causes its armature I96 which is piovtally mounted at I91 and normally urged in a clockwise direction by means of a spring I98 to be moved in a counterclockwise direction thereby causing its detent arm I99 to engage the teeth of an associated ratchet 29I which is securely mounted to a shaft 292. The shaft 292 has a stop arm 293 securely fastened thereto which limits the clockwise movement of the shaft and ratchet by engagement with a stop 294 toward which it is biased by means of a coil spring, not shown.

The second electrical circuit which is established upon the energization of the relay I81 may be traced similarly to that with respect to the energizing circuit for the relay I81 up to the conductor I86, thence to contact 296, through the armature I89 in engagement therewith, over a conductor 291 to junction point 298, over a conductor 299 to an armature 2| I of a relay 2 I 2 which isat this time in a de-energized condition, through a contact 213, over conductor 214, and through the winding of the relay 2 [2 to ground. As it was just mentioned that the circuit just established was traced through the armature 2i i and depended on its being in its unattracted condition due to the de-energization of the relay 252, the energization of the relay 212 will cause such circuit to be broken momentarily, thus once again causing de-energization of the relay H2. The relay 2E2 acts as a stepping relay for a sequence switch or finder which comprises six contact rings M6 to RI, inclusive. The sequence switch or finder is providedso that one contact point on each of the rings 211 and 2 i8 will be associated with the instant incoming selector circuit 14 and cause the alternating signals generated therein to be passed to an amplifier 223 in a manner and for a purpose which will be described hereinafter.

At such time as the stepping relay 212 advances the contact arms of the selector switch to a position whereby they engage the contact points as sociated with the instant example, which as may be seen on Fig. 3 is the third contact point, the circuit previously traced for the energization of the relay I81 over the conductor I83 to junction point I84 may be further traced over a conductor 224 to the third contact point of the selector ring 2H5, over the movable contact arm in engagement therewith, over a conductor 226 and through the right-hand winding of a relay 221 to ground. Upon the energization of the right-hand Winding of the relay 221, the associated armature 228 will be attracted thereto placing it in engagement with contact 22s and extending the circuit from the conductor 226 through the contact 229, over the armature 228, over a conductor 23!, through the left-hand Winding of the relay 221, over a conductor 232, over the conductor 214, and through the winding of the stepping relay 2I2 to ground. Such acts as a locking circuit for the relay H2 and thus prevents the stepping switch from operating to move the movable arms past the No. 3 contact point of the contact rings 216 to 22l, inclusive.

The relay 221 remains energized over its energizing circuit which was traced through the third contact point of the contact ring 215 and attracts its armatures 233 and 234 thereto, placing them in engagement with their associated contact points.

Due to the attraction of armature 233 a circuit is established which may be traced from the line 38 in the incoming selector circuit 14, over a conductor 236, through the third contact point of the contact ring 2l1, over the movable arm in engagement therewith, over a conductor 231, through the armature 233 and to the amplifier 223. Due to the attraction of the armature 234 a circuit may be traced from line 49 of the incoming selector circuit 14, over a conductor 2% to the third contact point of the contact ring 253, through the movable arm in engagement therewith, over a conductor 239, and through the armature 234 to the amplifier 223.

The amplifier 223 serves not only to amplify the alternating current signals transmitted from the v signaling generator 11 but also to convert them from alternating current to direct current sigrials.

If the above circuit connections occur at the time of the transmission of any signal from the signal generator 11 other than that of the start signal es, it will have no immediate efiect on the apparatus hereinafter to be described. Thus,

in the following description it should be assumed that the circuits previously traced have been set up and that the brush 8| is traversing the start segment 98 and sending an alternating carrier current indicative thereof to the amplifier 223, which is thereat converted to direct current.

The reception and conversion to the direct'current signal of the start impulse results in the establishment of a circuit which may be traced from the amplifier 223, over a conductor 24!, through the winding of a fast operating relay 242, through the winding of a slow operating relay 243 and over a conductor 244 back to the amplifier 223. The reason previously stated that no effect would result from the transmission of any other than the start signal at this time is due to the fact that the slow to operate relay 243 is responsive only to the start signal of every one of the transmitted signals and will not energize upon the reception of any other signals. Upon the reception of the start signal and the energization of the relays 242 and 243 their armatures 241 and 246, respectively, will be attracted thereto. Due to the energization of the relay 243 and the attraction of a second armature 248, an electrical circuit is established which may be traced from ground, through the armature 248, over a conductor 249, and through the winding of a relay 25l to grounded battery 252.

The resulting energization of the relay 25| causes its armature 253 to be attracted thereto resulting in the establishment of an electrical circuit from ground, over a conductor 254, through the attracted armature 253, over a conductor 256, and through the winding of a magnet 251 to grounded battery 258. The magnet 251 upon energizing attracts its armature 259, which is normally held away therefrom by means of 'a spring 26!, causing it to pivot about its pivot point 262 and cause its detent portion 263 to engage a tooth in the ratchet wheel 21", previously described, thereby causing the ratchet wheel to be stepped a distance equal to the distance between successive teeth in a counterclockwise direction. Aswas also previously mentioned, the detent I99 is in engagement with the teeth of the ratchet wheel 20! thus precluding the ratchet from moving back to its original position after the magnet 251 becomes de-energized.

The movement of the ratchet 201 causes its shaft 202 to move a similar distance resulting in a cam 264 which is securely fastened to the shaft 232 to move a similar distance. Such movement of the cam 264 causes the high portion of the periphery thereof to engage a movable swinger 266 and move it in a clockwise direction in engagement with an associated contact 261. Upon the closure of the contact pair formed by the swinger 266 and the contact point 261, an electrical circuit is established which may be traced from ground, through the contact point 261, over the swinger 266. over a conductor 268, through contact point 269, over a movable swinger formed as part of the common member I82, over a conductor 21!, and through the winding of a relay 212 to grounded battery 213.

The energization of the relay 212 causes its associated armatures 214, 216. and 211 to be attracted thereto resulting in the establishment of certain circuits.

One of the just mentioned circuits may be traced from ground, through the armature 214, over a conductor 218, through the movable arm and third contact point of the contact ring 2l9, over a conductor 219 and through the winding of to the alternating current source 282.

relay 62 (Fig. 2) to grounded battery 28l. The

. 63 through armature 6|, and from conductor 1| to conductor 13, through armature 12. Such formed part of the telephone circuit.

The attraction of the armatures 216 and 211 results in the establishment of an electrical circuit which may be traced from alternating current generator 282, through a conductor 283, over the armature 216, over a conductor 284, through the right-hand winding of a transformer 286, over a conductor 281, through the lefthand winding of a transformer 288, over a conductor 289, through the armature 211 and back As a result of the circuit just traced alternating current will be induced in the right-hand winding of the transformer 288, will pass over the conductor 29l, through the movable arm and third contact point of the selector contact ring 220, over a conductor 292, through the armature 12, over the conductor 13, through the connector 14, over the lowermost of the two lines |1 shown in the final selector I6, over a conductor 293, through a contact pair 294 at the called subscribers station B, over a conductor 296, through the right-hand winding of a printer magnet -291, through a condenser 298, and through an alternating current motor 299 utilized for driving the receiving monopulse printer.

The alternating current induced in the lefthand winding of the transformer 286 may be a conductor 306, through the left-hand winding of the relay 291, and through the condenser 298 to the motor 299. Inasmuch as the alternating current passes through the two windings of the magnet 291 in reverse directions no magnetic effect is produced but there is added a slight resistance to the current flowing to the motor 299. Such slight resistance merely diminishes slightly the alternating current supplied to the motor 299 but will not affect its operation due to the alternating current being supplied. However, direct current passes through the two windings in such a manner so that the magnetic effects are added, causing the magnet 291 to respond to the direct current. It should be further noted that even though the direct current is interrupted during signalling the alternating current is interrupted in one coil only and the motor 299 will continue to operate. A similar operation may be seen by reference to U. S. Patent No. 2,237,951, issued to L. M. Potts on April 8, 1941.

The reason for applying alternating current to the motor 299 at this time is to allow it to start into operation and come to an operating speed prior to the time that the printer is operated to record the code signals transmitted thereto.

While the transformers 286 and 288 have been shown as separate transformers such has been done for facility of illustration and actually the primaries are wound on a single magnetic core and the secondaries are also wound on the same magnetic core. The two secondaries are wound in such a manner that they both deliver the same phase alternating current. However, when direct current passes through the two series connected windings they cancel each other and produce no magnetic effect, but merely act as resistors.

At the time of energization of the relay 62, an electrical circuit is established which may be traced from grounded battery 391 (Fig. 3), over a conductor 308, through a contact pair 309 which is closed at this time, over a conductor 3| I, through the right-hand winding of the transformer 288, over the conductor 29| and swinger arm to the No. 3 contact point of the contact ring 220, over the conductor 292, through the armature 12 in engagement therewith, over conductor 13, through the connector 14 leading to the lowermost of the two lines H in the final selector l6, over the conductor 293, through the contact pair 294, over the conductor 296, through the right-hand winding of the printer magnet 291, over a joining conductor 3|2, through the left-hand winding of the printer magnet 291, over the conductor 306, through the contact pair 394 (now closed), over the conductor 303 to the uppermost of the two lines |1, through the connector 64 leading to the incoming selector circuit |4, over the conductor 63, through the armature 6|, over the conductor 302, through the third contact point and swinger arm in engagement therewith of the contact ring 22 I, over the conductor SM and through the left-hand winding of the transformer 286 to ground. The direct current just traced causes the printer magnet to remain energized and precludes the operation of the printer until such time as a signal is received which releases the printer for operation in accordance with the description in the aboveidentified Zenner patent. The direct current so generated has no effect on the driving motor 299 inasmuch as because of the condenser 298 it does not pass to such motor; the condenser 298 passes alternating current only.

Upon the energization of the slow operating relay 243 and fast operating relay 242, and subsequent attraction of the armatures 246 and 241, respectively, an electrical circuit is established which may be traced from ground, over a conductor 3| 3, through the armature 246, over a conductor 3|4, through the armature 241, over a conductor 3|6, and through the winding of a relay 3|1 to grounded battery 3|8. The energization of the relay 3|1 causes its armature 3|9 to be attracted thereto resulting in engagement with the contact point 32| and the breaking of the contact pair 322. However, the energization and the resultant attraction of the armature has no effect at this time.

As the signal generator 11 (Fig. 1) completes the transmission of the start signal and the brush 8| passes to the first insulated portion 99 of the segmented ring 18, a signal will no longer be incoming to the amplifier 223 which results in the de-energization of the fast operating relay 242 and the slow operating relay 243. Immediately, due to the dropping off of the armature 248, the relay 25| will de-energize causing its armature 253 to also fall away therefrom, in turn resulting in the de-energization of the stepping magnet 251. The magnet 251 no longer attracts its armature 259 thereby allowing the pawl 263 to return to its normally unoperated condition away from the ratchet 20|. Due to the operation of the detent I99 prior to this time,

through the relay 3H will not de-energize during this short transfer of ground circuits still there is no effect on the remaining circuits due to its de-energization.

As the brush 8| traverses further the segmented ring 18 causing the signal pulses llll to be transmitted over the line and to the amplifier 223, such signals will result in the fast operating relay 2%2 becoming energized but will have no effect on the slow to operate relay 243 which, as

previously mentioned, becomes energized only upon the receipt of the start signal due to its duration.

The energization of the fast operating relay 2 33 causes its armature 241 to be attracted thereto resulting in ground previously traced through contact 323 no longer being supplied to the circuit for the operation of relay 3H and inasmuch as relay 243 is not energized with its armature 2A6 attracted thereto, no ground will at this time be supplied for the relay circuit.

However, even though the relay 3|! becomes deenergized and its armature 3l9 falls away therefrom allowing the contact pair 322 to once again close, still there will be no effect on the remainder of the circuit at this time.

The receipt by the amplifier 223 of the signals generated as the brush 86 traverses the segmented ring 82 and as the brush 9| traverses the segmented ring Bl will have no effect on the signaling circuit other than that just described upon I the receipt of the signals from segmented ring #8.

It is to be remembered that mention was made that the brushes 8 l, 86, and SH continuously operate to traverse their respective rings. Therefore,

after the cycle is completed, which was described immediately above, the brush 8! will once again traverse the start segment 98 of the segmented ring '53 resulting in the long duration start si nal being transmitted over the line and received by the amplifier 223. Upon the receipt and conversion to direct current of such signal the fast operating relay 2 32 and the slow to operate relay 2% will once again be energized over the circuit which was pr viously fully described. As a result of the energization of the relay 2% its armature 248 is attracted thereto once again establishing the electrical circuit for the energization of the relay 25! which thereupon causes its armature 253 to be attracted thereto. The attraction of the armature 253 once again establishes the circuit for the energization of the magnet 251 causing its armature 253 to be attracted thereto and the pawl 263 to once again engage the ratchet Wheel 2t! and turn it in a counterclockwise direction a distance equal to the distance between successive teeth, in which position it is held by the detent E99 which is still in engagement with the teeth of the ratchet. Upon such movement of the ratchet 29! its shaft 202, to which it is securely fastened, likewise turns a similar amount thereby causing the cam 26 to likewise move in a counterclockwise direction causing its high portion to engage a movable swinger 324 and cause it to engage the associated contact 326.

Upon relays 242 and 243 becoming energized 'pair 3535.

and attracting their armatures 24? and 246, re-- spectively, a circuit is once again established for placing ground in the circuit of the relay 3]? thereby allowing such relay to energize and attract its armature tie thereto. Such attraction results in the contact 32I being closed and the contact pair 3222 becoming opened.

Upon the counterclockwise stepping oi the cam 25$ and the resultant movement of the swinger 324 into engagement with the contact 32%, an electrical circuit is established which may be traced from ground, over the swinger 324, through the contact 325, through a contact 32?,

through a movable swinger forming part of the common member 582, over a conductor 32B, and

through the winding of a relay 325'? to grounded battery 33%. The energization of the relay 329 causes its armature 332 to be attracted thereto placing it in engagement with its associated contact 333 and causing the opening of the contact The result of such occurrence is that battery 3%? no longer will be supplied over conductor ellt and through contact pair 339 for supplying direct current to the printer magnet 2% but instead grounded battery 36? will be supplied through armature contact 32!, over a con- 'ductor 335., through armature 332, through contact 333, and over the line ill, as previously described, thereby causing the printer magnet 29'? to remain energized.

As the brush of the signal generator '5! passes from the start segment as to the insulated segment 99, the fast operating relay 242 and the slow operating reiay 2&3 will once again become de-energized, thereby resulting in the armatures 2M and t lt, respectively, no longer being held attracted and falling away therefrom. The only effect, with respect to the signal cir cuit is that ground for the energization of the relay SH no longer may be traced through both of the armatures 2s? and 2% but instead will now be traced through the contact 323 and the armature 241. At this time also the armature 2&8 will no longer be attracted resulting in the breaking of the circuit for the energization of the relay '25! which causes its armature 25% to also fall away. This in turn results in the circuit for the energization of the stepping magnet 25'? being broken with the pawl 233 returning to its normal position out of engagement with the teeth of the ratchet 29!. However, because detent we remains in engagement with the teeth of the ratchet, the ratchet will remain in stepped position.

As the brush 8! of the signal generator ll? passes to the first signal segment 53% of the segmented ring it which is indicative of the first calling station letter (B) such will be transmitted to the amplifier 223, whereat it is converted to 'direct current, resulting in the fast operating of any signal other than the start relay 25? becoming energized. Inasmuch. as, as

was previously stated, the slow operating relay 243 does not become energized upon the receipt signal, it will not become energized at this time. The resultant attraction of the armature 2 1 1? of the will remove ground supplied for relay 3H, over omiductor 313 and through contact 323 and as 15 battery 301 from supplying direct current to the printer magnet 291 inasmuch as contacts 32| and 309 are both open at this time, thus allowing the printer to start operating in accordance wiith the signal interval, in a manner described fully in the Zenner patent.

Upon the brush 8| passing from the segment indicative of the letter B to the subsequent insulated segment 99, no signal impulse will be received by the amplifier 223 and the relay 242 will become de-energized. Such results in the armature 241 falling away and ground once again being supplied over conductor SIB and through contact 323 and armature 241 for the circuit of relay 3| 1 thereby causing that relay to energize. Upon such occurring the armature 3|9 becomes attracted, engages its contact 32I, and battery 301 is once again supplied over the previously traced circuit thereby resulting in the energization of the printer magnet 291. Such results in the letter B being recorded by the monopulse printer.

The apparatus will thereafter function in a similiar manner in order that the letters U0 and the numerals 6200 may be transmitted and recorded by the printer at the called subscribers station B. It should be remembered that during all this time, that is, as the brush 8| completes its passage over its signal segments and as the br-ush es 86 and 9| traverse their signal segments all of which will be recorded in accordance with the monopulse code at the receiving printer, that the slow to operate relay 243 will not become energized.

After the brushes have made a complete cycle or traversal of their associated rings, the brush 8| will once again traverse the start segment 98 causing the start signal to be transmitted over the line to the amplifier 223 wherein it will be converted to direct current. Such signal causes the fast operating relay 242 to become energized and also causes slow to operate relay 243 to become energized, causing the armatures 241, 246, and 248 to be attracted.

The attraction of armature 248 results in a circuit once again being established for the energization of the relay 25| attracting its armature 253 thereto. The attraction of the armature 253 establishes the circuit once again for the energization of the stepping magnet 251 thereby attracting its armature 259 and causing the pawl 263 to step the ratchet 20| another step. Such movement of the ratchet causes the shaft 202 to likewise move resulting in the cam 264 being moved a third step in a counterclockwise direction. The effect of such stepping of the cam at this time is to cause its high portion to move member I82 in an upward direction resulting in the movable swingers connected thereto being moved away from engagement with the contacts I8I, 269, and 321, thereby causing certain circuits to be broken, as will now be described.

The opening of the circuit at contact 321 results in the de-energization of the relay 329 thereby removing the armature 332 from engagement with the contact 333 and allowing the contact pair 309 once again to close. The disestablishment of such circuit allows grounded battery 301 to be applied directly to the printer magnet 291, over the conductor 308, through the contact pair 309, and over a circuit which was previously described.

The opening of the circuit at contact 269 removes ground which was previously supplied for the energization of the relay 212 and thereby results in the de-energization of such relay causing its armatures 214, 216, and 211 to fall away from their associated contacts. As a result of armature 214 no longer engaging its associated contact the circuit previously traced for the energization of the relay 62 (Fig. 2) no longer will be established and such relay will become de-energized, its armatures 6| and 12 no longer being attracted thereto. The result of thesev armatures no longer being attracted to their relay serves to disconnect the selector contact rings 220 and 22| from the lines I1 leading to the called subscribers station B, thus breaking the circuit previously described for the direct current to the printer magnet 291, but instead completes connecting lines I1 in the telephone circuit initially described,

The relay 212 being de-energized results in the armatures 216 and 211 no longer being attracted and serves to remove the alternating current source 282 from the transformers 286 and 281 as previously explained. Even though such did not occur the alternating current previously described as being supplied to the printer motor 299 causing it to operate would no longer perform such function due to the fact that the armatures 6| and 12, over which the circuit for such alternating current was traced, no longer are in a position to connect to the lines I1 in such a manner as has just been described.

As a result of the circuit being broken at contact |8| the battery which was supplied for the relays I81, 2|2, and 221 no longer will be supplied and these relays will all become de-energized. AS a result of the de-energization of the relay 221, its armatures 233 and 234 will no longer be attracted and the circuit will be broken for supplying the signals generated by the signal generator 11 to the amplifier 223.

Upon the de-energization of the relay I81 its armature I88 will no longer be attracted thereto and because of this will break the circuit which had been traced for the energization of the magnet |93. The de-energization of such magnet will result in its armature I96 no longer being attracted thereto and under the influence of the spring I98 being biased in a clockwise direction in which position the detent portion I99 is no longer in engagement with the teeth of the ratchet wheel 20|. Under this condition the ratchet wheel 20| will return through spring power, which is not shown, in a clockwise direction to an unoperated position whereat its stop arm 203 engages the limiting stop 204.

As the ratchet 20| and connected shaft 202 move in a clockwise direction, the cam 264 will move similarly. Such movement to the cam 264 returns it to its normal unoperated position, whereat its high portion will no longer be presented to the swingers 266 and 324 and the member I82. The latter elements will thus return to the condition initially described.

Thus, it may be seen that after a complete signal has been received and recorded at the called subscribers station B which is indicative of the calling subscribers number, the apparatus will automatically preclude itself from further operation. Under this condition the bell ringing mechanism will continue to operate until such time as the subscriber at the calling station A returns his receiver to the hook thereby causing the telephone apparatus to relinquish all the selecting circuits under the control of the selector control relay in a manner which is well known in the telephone art.

It might be mentioned at this time with respect to the prior description wherein it was stated that after a predetermined number of bell rings that the ratchet wheel I63 would be advanced sumciently to cause the movable swinger I16 to engage its associated contact H1, that such predetermined number of rings should be picked in order to allow a person sufficient time to reach his telephone but not to allow too much time to elapse. In the event that the latter were true, called subscribers may refuse to anwer their telephone until such time as the calling subscribers number had been recorded at the called subscribers station and thus if the called subscriber felt like conversing with the particular person whose number had been recorded he would remove his receiver. Under this latter condition too much equipment would be necessary and too much time expended in the use thereof in order for it to be a worth while service.

Referring back to Fig. l and the calling subscribers station A, after the calling subscriber has assumed that there is no one at the called station and decides to abandon the telephone call, he returns his receiver to the hook, which, as previously described, is well known in the telephone art and which causes the relinquishment of the seized circuits. Also, as is well known in the telephone art, this results in the cut-off relay il i becoming de-energized thereby resulting in the breaking of the circuits from the si naling generator H to the telegraph circuits previously transmitting the number 6200. At this time the selector cam I33 will also be positioned in such a manner that no circuit may be established therethrough and the remaining circuit from the signal generator 11 will be disconnected from the telephone lines. Thus, at this time the signal generator Tl no longer will supply alternating current carrier signals to the telephone lines but instead will continue to operate having no effect in the circuits. However, at such time as another call is instituted from the calling station A the signal generator 11' will once again be connected in the line circuits in a manner which has previously been described.

In the event that it is desired to completely preclude the possibility of a called subscriber refusing to answer his telephone until such time as the calling subscribers number has been recorded thereat, apparatus has been provided in a modification of the invention to overcome such contingency. Such modification is shown in Fig. 4.

In view of the fact that in main the apparatus of Fig. 4 is similar to that of Fig. 1 and operates in a similar manner, like reference numerals are utilized in Fig. 4 wherever possible and will indicate members similar t those shown and described with respect to Fig. 1.

Referring specifically to Fig. 4, an assumption should be made that the calling subscriber at station A has removed his receiver and has dialed the number of the desired called subscribers station B. The apparatus will operate in a manner similar to that previously described in order to complete a telephone circuit which as previously mentioned was traced through the winding of the relay 23. Upon the energization of the relay 33 its armatures 336, 331, and 333 will be attracted thereto.

Due to the attraction of the armature 338 an electrical circuit is established which may be traced from ground, through armature 338, over a conductor 33S, and through the winding of the slow to release relay 34! to grounded battery phony operation.

The signal generator 11 operates in a manner similar to that described with respect to Fig. 1 to generate signals indicative of the calling subscribers number over the conductors I02 and M3,, through the selector cam I33, over the conductor we and through the armature I03. The circuit may then be traced over a conductor 348, through a condenser therein, through the armature 343, over a conductor 349, through armature 331, and over a conductor 35!). However, the circuit for impressing the generated signals over the circuit just described to the line 24 at the line finder district [2 will not be completed at this time because in order for such establishment it must be traced through the armature 331 which does not make contact with the conductor 349 due to its being held in its attracted position by the energization of the relay 23.

The bell ringing mechanism will operate similarly to that previously described, and the apparatus of Figs. 2 and 3 will also operate similar- 1y with the exception that no subscriber's station identifying signals will be transmitted over the telephone circuit to cause recording at the called subscribers station.

At such time as the calling subscriber at station A decides that the called subscriber at station B is not present and returns his receiver to the hook, the apparatus will function to cause the de-energization of the relay 23. Even though the armature 338 is no longer attracted to supply ground to the energizing circuit of the relay 34!, this relay will not immediately de-energize inasmuch as, as was previously mentioned, it is a slow to release relay.

The armature 331 of the relay 23 will return to its unattracted position thus allowing the generated signals to pass in a manner similar to that described with respect to Fig. l to the conductor led, through the armature I36, over the conductor 348, through the armature 343 which is in its attracted position, over the conductor 349, through the armature 331 now in its unattracted position, and over the conductor 350 to the line 24 from whence it will pass over telegraph circuits to the apparatus already described of Fig. 3.

The apparatus disclosed in Figs. 2 and 3 will function in a manner similar to that previously described in order that the generated signals which are transmitted over the telephone circuit may be recorded at the called subscribers station B. The slow to release relay 34! will be so timed that it will not be de-energized until such time as a complete calling subscribers signal has been recorded. At this time, however, the relay 34I de-energizes thereby allowing its armature 343 to return to its unattracted position thus breaking the circuit which was previously described as having been established for the conduction of signals generated by the signal generator TI to the line 24 of, the telephone circuit. Thus at this time the apparatus will once again be in readiness for the calling subscriber at station A to initiate another telephone call and to operate at that time.

It might be mentioned at this time that upon the replacing of the receiver to the hook at the calling subscribers station even though relay 23 becomes de-energized immediately, the remaining circuit connections between the calling subscribers station A and the called subscribers station B will not be relinquished until such time as the called subscribers number may be recorder at the called subscribers station. Such occurs because the relay 341 is energized during this time, and its armature 344 is attracted thereto thus supplying ground over an obvious circuit through the sequence switch cam 341 for the selector control relay, not shown.

The above apparatus will operate to record a calling subscribers number at the called subscribers station but has no provisions wherein messages or other material may be transmitted and recorded at the called subscribers station. In view of such, apparatus disclosed in Fig. has been provided which contemplates the use of a leave word operators position for receiving orally a message to be left at the called subscribers station, the operator controlling transmission of such message.

Only sufiicient apparatus has been provided in Fig. 5 in order to disclose the operation of this embodiment of the invention. It is contemplated that the apparatus for causing the bell ringing mechanism to operate and the apparatus operating to translate and record the signals at the called subscribers station, such as shown in Figs. 2 and 3, will be incorporated for use with the present modification as will the regular panel dial system telephone circuits.

Specifically, referring to Fig. 5, a calling subscribers station has been identified by the numeral 35| which is connected by means of lines 352 through a final selector 353 to the instant leave word operators station. It might be noted that while only a final selector has been disclosed, it is to be understood that a line finder district, incoming selector, and any other necessary selectors may be included even though not shown. The calling subscribers station 35I will be connected to the operators leave word system through the various selectors including the final incoming selector 353 as a result of the calling subscriber dialing some number associated with the leave word operator, such as the numeral 0,

for instance. As a result of such dialing, a circuit will be established which may be traced over line 352, over a conductor 354, through an armature 356, through the left-hand winding of a relay 351, to grounded battery 358. As a result of the energization of the relay 351 its armature 359 will be attracted thereto resulting in the grounded battery 358 being applied through the armature 359 and over a conductor 36I to the grounded illumination source 362, such as a normal light bulb. The illumination of such light will notify the leave word operator that somebody desires to communicate with her and she thereupon will insert the plug 363 in the jack 364. Such action results in grounded battery 366 being supplied through the plug and jack connection, through the winding of a relay 361 to ground, resulting in the energization of that relay and the attraction of its armature 356. Upon the armature 356 moving toward the relay it opens the circuit which was previously traced over conductor 354 and through the armature 356 for causing the illumination of the light 362, thereby resulting in the light being extinguished.

At the same time, the operator may throw the the associated key contacts 369 to be removed from engagement with their inner contacts and placed in engagement with their outer contacts. Such action causes the plug 363 to be connected over the plug leads, through the key contacts 369 and their outer associated contacts to an operators set which is indicated generally by the numeral 31! and which is of the type in general use at the present time. The leave word operator may thus communicate orally, utilizing the set 31!, with the calling subscriber, thereby being advised of the message which the calling subscriber wishes delivered to the called subscriber.

After the operator has been advised as to the desired message the plug 363 will be removed from engagement with the jack 364 and inserted in the jack indicated generally by the numeral 312 instead. The key 368 Will be withdrawn from engagement with its contacts 369 and instead placed in a position to engage its associated contacts 313 in such a manner as to place them in engagement with their outer contact points instead of their inner contact points. The result of such action is to establish a circuit including the dial unit 314, through the outer contacts associated with the key contacts 313, through these key contacts, over the conductors 316, through the key contacts 369 to the plug 363, thence to the jack 312 and over the telephone circuit. The operator thence will operate the dial 314 dialing the proper number for the called subscribers station which will operate through line finder district indicated generally by the numeral 311, through the regular telephone sequence switches which are not shown, and eventually over lines 318 to the called subscribers station 319-. The effect of this will be to complete a telephone circuit between the leave word operator's station and the called subscribers station.

After such circuit has been established and the standard telephone bell ringing mechanism has operated in a manner well known in the art and as indicated previously, the apparatus disclosed in Figs. 2 and 3 will operate in a manner as described with respect to the principal embodiment of the invention. Thereafter the operator will remove the key 368 from engagement with its associated key contacts 313 allowing such key contacts to engage their inner contact points resulting in the dial unit 314 being disconnected from the circuit. Simultaneously a key will be operated to cause the key contacts 38I to engage l their associated contact points resulting in an alternating current generator 382 being connected over the conductors 383 to the primary of the transformer 384 which induces current in the secondary windings of the transformer 384 which current passes over the conductors 386 to the contact points associated with the key contacts 38E and thence over previously traced circuits including key contacts 313, the conductors 316, the key contacts 369, the plug 363 and the jack 312. However, the alternating current from the source just described does not normally pass over the described circuits because of a shunt circuit between the conductors 386 which includes a conductor 381, a manually operable key contact pair 388, a contact pair 389 and a conductor 39!. Thus, during a normal condition at which time the key contact pair 388 is closed as is the contact pair 389, a shunt will exist on the line whereby no alternating current will be transmitted thereover.

The normally closed contact pair 389 is within a monopulse transmitter 392 which is of the type disclosed and described in U. S. Patent 2,173,147 issued to W. J. Zenner on September 19, 1939. Such patent discloses a similar contact which is likewise normally closed.

In order for the apparatus to be put into operation the operator must open the key contact pair 383 twice in succession, each time of a fairly long duration in order that the shunt may be removed from the line and alternating current impulses may be transmitted thereover which will cause the operation of the apparatus shown in Fig. 3 and particularly the double stepping of the ratchet 26! to advance the cam 264 to a position whereat the movable swingers 266 and 32s engage their associated contacts Zlil and 526, respectively. As has been fully described hereinbefore, such results in the monopulse receiver at the called subscribers station being conditioned in readiness for the receipt of monopulse signals and the recording of the proper message in response thereto.

Thereafter, the key 388 will be again closed resulting in the shunt once again being supplied to the circuit, thereby terminating the transmission of alternating current thereover. However, the leave word operator will now operate the monopulse transmitter 392 in a manner fully described in th just previously mentioned Zenner patent resulting in the contact pair 339 being opened in accordance with monopulse signals for the characters of the message to be transmitted which has the effect of once again removing the shunt from the circuit and allowing the alternating current to pass thereover in accordance with the monopulse signals. Such current will be received in the amplifier and cause the operation after conversion to direct current of the relays and apparatus as disclosed and in a manner described with respect to the principal embodiment.

It should be remembered that though alternating current has been described as passing over the line, direct current will still be utilized for the telephone circuit connection as is normally done in the telephone field.

After the leave word operator has transmitted the entire message by means of operating the monopulse transmitter 382, the plug 363 may be removed from the jack 372 thereby resulting in the telephone circuits becoming disestablished and returning to their original unselected conditions. Oi course, the key .388 may also be operated to send a long pulse, which will cause operation similar to that of the initial description.

While a single leave word operators unit has been shown and described it should be noted that there may be several in each exchang which may also have several operators and apparatus for their use which would include a plurality of jacks 35d and lights 362 in order that more than one call could be handled at a single time at the leave word operators station.

t is obvious that both the initially described apparatus and the leave word operators apparatus may be utilized in the same system. Thus, the latter apparatus would only be utilized when it is desired to leave .a message other than the mere calling subscribers designation,

It should also be noted that the manual operable key 388 which has been provided for the transmission of two long impulses may be substituted, by a button operated commutator or by any other means which will serve the purpose.

iii

Even though specific embodiments of the invention have been described it .is fundamental that such invention is not limited to the specific disclosures shown, but instead includes any modifications or alterations which incorporate the spirit of the invention.

W hat is claimed is:

l. in combination with a telephone circuit including a central station, a calling subscribers station, a called subscrib'ers station, and bell ringing mechanism, of means at said central station to generate repeatedly a group of signals indicative of the calling subscribers station, means to impress the repeated group of generated signals on said telephone circuit when said circuit is in a ringing position, a telegraph recorder at said called subscribers station, means to condition said telegraph recorder for operation, means to cause one only of said repeated group of generated signals indicative of said calling subscribers station to be recorded by said telegraph recorder, and means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism.

2. In combination with a telephone circuit in cluding a central station, a calling subscribers station, a called subscribers station, and 'bell ringing mechanism, of means at said central station to generate repeatedly a group of signals indicative oi the calling subscribers station, :means to impress the repeated group of generated signals on said telephone circuit when said circuit is in a ringing position, a telegraph recorder at said called subscribers station, means to condition said telegraph recorder for operation, means to cause a group of generated signals indicative of said calling subscribers station to be recorded by said telegraph recorder, means to preclude the recording of more than a single group of said repeatedly generated group of signals indicative of said calling subscribers station, and means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism.

3. In a communication system, a telephone circuit including a central station, a calling subscribers station, :a called subscribers station and bell ringing mechanism, means under the control of the calling subscribers station to place said circuit in a ringing position and cause open ation of said bell ringing mechanism, means at said central station to generate repeatedly a group of signals indicative of the calling subcrib-ers station, a telegraph recorder at said called subscribers station, means to condition said telegraph recorder for operation, means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism, means operating after said ringing position is discontinued to cause said repeated group of generated signals to be impressed on said circuit, and means to cause one only of said repeated group of signals indicative of said calling subscribers station to be recorded on said telegraph recorder.

4. In a communication system, a telephone circuit including a central station, a calling subscribers station, a called subscribers station and bell ringing mechanism, means under the control of the calling subscribers station to place said circuit in a ringing position, and cause operation of said bell ringing mechanism, means at said central station to generate repeatedly a group of signals indicative of the calling subscribers stdtion, a telegraph recorder at said called subscribers station, means to condition said. telegraph recorder for operation, means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism, means operating after said ringing position is discontinued to cause sad repeated group of generated signals to be impressed on said circuit, means operating in response to the repeated group of signals indicative of said calling subscribers station to further condition said telegraph recorder for operation, and means responsive to a succeeding one of said repeated group of signals indicative of the calling subscribers station to cause the operation of said telegraph recorder.

5. In a communication system, a calling station, a called station, a central station, bell ringing mechanism, means at said central station to generate repeatedly a group of signals indicative of the calling station, means to connect said calling station and said called station through said central station for communication, a recorder at said called station, means to condition said recorder for operation, means to transmit said repeated group of code signals indicative of said calling station, means to cause said recorder to respond to one onl of said repeatedly transmitted group of signals, and means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism.

6. In a combined telephone-telegraph circuit, a calling subscribers station, a called subscribers station, means to condition a circuit between said calling and called subscribers stations, means to generate alternating current signals on said circuit indicative of said calling subscribers station, a telegraph recorder at said called subscribers station, means to convert said alternating current signals to direct current signals, means responsive to the failure of a talking circuit to be established and under the control of said direct current signals to condition said printer for operation, and means to cause said printer to record signals indicative of said calling subscribers station.

7. In a call recording system, a calling subscribers station, a called subscribers station, a central station, bell ringing mechanism, means to condition a circuit between said calling and called subscribers stations through said central station, means at said central station to generate on said circuit repeatedly a group of signals indicative of said calling subscribers station, a recorder at said called subscribers station, means to condition said recorder for operation, means to cause said conditioning means to operate after a predetermined period of operation :of said bell ringing mechanism, means responsive to certain of said repeated group of signals to further condition said recorder for operation, and means to cause the succeeding repeated group of signals to be recorded by said recorder.

8. In a call recorder system, a calling subscribers station, a called subscribers station, a central station, bell ringing mechanism, means to condition a circuit between said calling and called subscribers stations through said central station, means at said central station to generate repeatedly a group of signals indicative of said calling subscribers station, each of said repeated group of signals including an initial start impulse, a recorder at said called subscribers station, means to condition said recorder for operation, means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism, means under thecontrol of said start impulses to further condition said recorder for operation, means under the control of said start impulses to cause said recorder to record one of said repeated group of signals indicative of said calling subscribers station, and means under the control of said succeeding start impulse to preclude further operation of said recorder.

9. In combination with a telephone circuit including a calling subscribers station, a called subscribers station, and means to establish a circuit between said stations including tip, ring, and sleeve connections, of means to generate signals indicative of the calling subscribers station, means to cause some of said signals to be impressed on said sleeve connection, means to cause the remaining of said signals to be impressed on said ring connection, and means to cause all of said signals to be transmitted to said called subscribers station.

10. In a call recording system, a calling subscribers station, a called subscribers station, means to transmit a plurality of similar groups of signals indicative of said calling subscribers station, means to precede each group of signals by a special signal longer than the longest signal in each group, a recorder at said called subscribers station, and means controlled by said special signal to render said recorder responsive to a single group of signals only.

11. In a communication system, a calling station, a called station, switching apparatus, means to extend a circuit between said stations through said switching apparatus, means to generate groups of signals indicative of said calling subscribers station, means responsive to a disconnect signal from said calling station to impress said groups of signals on said circuit, means to .prevent said switching apparatus from becoming released, and means to record a single group of signals at said called station.

12. In a communication system, a calling station, a called station, switching apparatus, means to extend a circuit between said stations through said switching apparatus, means to generate groups of signals indicative of said calling subscribers station, means responsive to a disconnect signal from said calling station to impress said groups of signals on said circuit, means to prevent said switching apparatus from becoming released, means to record a single group of signals at said called station, and means to release said switching mechanism to disconnect said circuit after said single group of signals is recorded.

13. In a call recording system, a calling subscribers station, a called subscribers station, a central station, bell ringing mechanism, means to condition a circuit between said calling and called subscribers stations through said central station, means at said central station to generate on said circuit repeatedly a group of signals indicative of said calling subscribers station, a recorder at said called subscribers station, means to condition said recorder for operation, means to cause said conditioning means to operate after a predetermined period of operation of said bell ringing mechanism, means responsive to certain of said repeated group of signals to further condition said recorder for operation, means to cause the succeeding repeated group of signals to be recorded by said recorder, and means under the control of the next succeeding repeated group of UNITED STATES PATENTS signals to preclude further openaltion of said rerd Number Name Date MARTHA W. 0. POTTS, 1,337,310 Goodrum Apr. 20, 1920 Ewecutria: Under. the Last Will and Testament of 1,793,762 Tilden Feb. 24, 1931 Louis M. Potts, Deceased. ,810,865 Warwick June 16, 1931 1,887,588 Elkins Nov. 15, 1932 REFERENCES CITED 2,094,151 Goheorel et a1 Sept. 28, 1937 The following references are of record in the i0 file of this patent:

Images