US1845034A - Signaling apparatus for recording systems - Google Patents

Signaling apparatus for recording systems Download PDF

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Publication number
US1845034A
US1845034A US501988A US50198830A US1845034A US 1845034 A US1845034 A US 1845034A US 501988 A US501988 A US 501988A US 50198830 A US50198830 A US 50198830A US 1845034 A US1845034 A US 1845034A
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line
recording
telephone
generator
recording apparatus
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US501988A
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Carroll O Bickelhaupt
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AT&T Corp
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American Telephone and Telegraph Co Inc
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M1/00Substation equipment, e.g. for use by subscribers
    • H04M1/64Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations
    • H04M1/65Recording arrangements for recording a message from the calling party

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  • This in'vention' relates to signalingand recording systems. More particularly, this invention relates to improvements in and additions to apparatus for recording messages which may be transmitted over a signaling circuit, such as a telephone line. Still more particularly, this invention relates to arrangements for indicating that recording eqluipment, which may be connected to a te ephone line, has been started in' operatlon and remainsin operation.
  • This signal may be This invention is intended to provide a signal at'the instant recording apparatus is operatively connected to a telephone line. It is also intended to provide a similar signal at re ular and predetermined intervals r while the recording apparatus rerendered audible or'visible, as may be found desirable. Moreover, this signal may be transmitted to the called party or to the calling party or to a'telephone operator'or to any-two of these persons or all 'ofthem, and
  • One of the objects of this invention is to notif a. party to a telephone conversation that is conversation is being recorded.
  • Another of the objects of this invention is to apprise all the parties to a telephone conversation. that their conversation is being recorded.
  • Still another object of the invention is to provide an indicating signal at the begincARnoLL o. BICKELHAUPT, or NEW YORK, 1v. 1., Assreicon 'ro nmnrcm 'rnnnrnonn ning of the recording process and to transmit that signal to all the parties to a telephone conversation which is being recorded.
  • a further object of this invention is to provide an-indicating si al not only at the beginning of the recor ing process but also at regular intervals thereafter throughout the recording process.
  • Fig. 1 schematically shows one form of arrangement for recording a telephone conversation in accordance with the princi les of this invention.
  • the equipment at the central ofli'ce may operate in response to signals from either of the stations T or T or this equipment ma be connected to the line L at the instance 0 the telephone operator at the central ofl'ice.
  • the reference character Q represents'a paratus for recording telephone signa
  • This recording apparatus may be located at or near stations T or T or at or near the central ofiice CO.
  • This recording apparatus may, of course,-be connected to the telephone line L whenever desired merely by .the closure of a switch W.
  • ' Therecording apparatus Q may include,
  • the rotating device may be coupled to a cam mechanism M and the cam mechanism may control a source of current which may be an alternating current generator G, the details of operation of one form of which will be described in greater detail hereinafter.
  • the generator G may be one capable of producing current of any frequency, preferably an audible frequency suitable to effectively energize the telephone receiver or other electromagnetic device at the telephone substation sets T and T and the equivalent device at the central oflice CO.
  • the generator G may, of course, be any form of electrical oscillator and it may be of the vacuum type, if desired.
  • Fig. 2 shows one form of arrangement for producing a tone signal suitable for transmission over line L.
  • a cam M is mounted on a shaft S which is mechanically coupled to the revolving turntable or cylinder holder H, described in connection with Fig. 1 of the drawing.
  • the cam M and the revolving device H may be connected directly, or indirectly through a geared train.
  • the cam M will make a predetermined number of revolutions during each minute or during each interval of, for example, five minutes.
  • a metallic arm K will follow the outer surface of the cam M and during each complete revolution the arm K will make good electrical contact with another arm K for abrief space of time which may, for example, be several seconds. During this short interval, the arms K and K will be in circuit with each other through a pair of-metallic contacts N and N which are permanently connected to the arms K and K respectively. It will be obvious that the arm K is stationary and that the arm K is movable and, moreover, these arms may be brought into electrical contact with each other in any other well known manner.
  • a bar of insulation I may, if desired, be placed between the arms K and K and it may be permanently fastened to either of these arms so that they may be maintained a predetermined distance apart, and this feature will be especially desirable if the arms K and K are equipped with contacts which are flexible.
  • the arm K is connected to a battery B, one terminal of which is grounded.
  • the arm K is connected to the winding of a relay B, one terminal of which is also grounded.
  • the armature A of the relay R is permanently connected to an arm K and these elements always more in unison. lVhcnever the winding of the relay It becomes encr gized, the arm K will be brought into an electrical circuit with the arm K, through a pair of cohtacts designated 'N and N,.
  • the fixed terminal of the armature A is connected to one side of, the line L, while the arm K is connected to one terminal of the alternating current generator (5?.
  • the other terminal of the generator G is connected to the other side of the line L through a condenser C.
  • relay R When the arms K and K are in circuit with each other, relay R will become operated and this relay will remain operated as long as these arms are so connected. During this period the generator G will send a pulse of alternating current over the arms K and K through the condenser C and over the line L. This pulse will be interrupted just as soon as the arms K and K are disconnected from each other. Shortly thereafter the cam M will again cause the arms K and K to make contact with each other and the generator G will then transmit another pulse of alternating current over the line L. Thus, the cam mechanism will cause pulses of alternating current to be transmitted over the line L and this will occur throughout the recording process.
  • the generator G produces an alternating current of a frequency within the range of audibility
  • the audible signal will be heard regularly and periodically at each electromagnetic receiver connected or otherwise coupled to the line L, and this signal will disappear when the recording mechanism ceases to function.
  • the relay R may assume any desired form. Its armature A may be equipped with a front contact which will become closed by the armature upon the operation of the relay. This front contact may extend to one terminal of the generator G and it will connect this generator to the line L through the series condenser C and the armature A. This construction will eliminate the arms K and K, as well as their associated contacts N and N.
  • the operating surface of the cam M has not been shown precisely in the shape it will have when used in carrying out the principles of this invention. This cam will have a surface which will quickly bring the arm K into circuit with the arm K immediately at the beginning of the recording process.
  • the shape of the cam surface will also-be such that thearms K and K will remain in contact with each other for a predetermined interval of time so that a cleancut pulse of alternating current may be transmitted by the generator G over the line L.
  • This cam mechanism will also be so arranged that the contacts K and K will be-positive-' 1y disconnected from each other after the cam M has ceased to revolvedisconnection of the generator from the line L after the recording process has stopped.
  • the current of the generator G will operate electromagnetic receivers which may be connected or coupled to the line L and create audible signals in these receivers,it will be understood that visible signals may, if desired, beproduced.
  • transformers, tuned circuits, filters or the like may interconnect one or more lamps or other visible indicating devices to the line L so as to produce suitable visible signals.
  • the frequency of the current of the generator G will not have to be within the range of audibility-
  • the generator G has been described as intermitently operated. If desired, the generator G may be continuously operated.
  • the generator G may be maintained in continuous operation during the recording process bydirectly or indirectly coupling this generator to the revolving turntable or cylinder holder H of the recording apparatus.
  • the generator G may be replaced by a phonographic device or reproducer which will be operated either intermittentlyor continuously during the recording process, as
  • the record reproduced and transmitted over the line L may carry any predetermined signal, or any desired word, such as recorder or record or the like; or it may be any predetermined phrase or sen tence.
  • the generator G may be replaced by a modulator to which may be connected a plurality of generators or oscillators producing currents having different frequencies which, when modulated, form a background tone This will insure the amplitude, its amplitude being alternately increased or decreased.
  • This invention represents an innovation in the art of recording telephone messages. It permits recording operations to occur only with the knowledge of the persons engaged in the telephone conversation; The invention is intended to apprise the parties to the conversation that the recording rocess has started, and it continues to noti these parties at regular intervals or continually throughout the conversation.
  • the method 0 apprising a party to a telephone conversation that hls conversation is being recorded, which consists in transmitting to that party an audible tone at the be ginning of the recording process, periodicall reproducing that tone at regular intervals dining the recording process, and removing that tone at the end of the recording process.
  • the method of apprising a party to a telephone conversation that h1s speech is be ing recorded which consists in producing and transmitting a characteristic phonographic tone to said party and reproducing and retransmitting that phonographic tone to said party at brief regular intervalsthroughout the recording process.
  • Apparatus for recording signals transmitted over a telephone line including means for indicating that the recording apparatus has started in operation, and automatic means for periodically indicating at regular intervals that the recording apparatus re mains in operation.
  • Apparatus for recording signals transmitted over a telephone line including automatic means for indicating at predetermined regular intervals that the signals are being recorded.
  • a signal system comprising a line, a tone generator, recording apparatus, and means controlled by said recording apparatus for connecting said tone generator to said line at regular and predetermined intervals.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Telephonic Communication Services (AREA)

Description

Patented Feb. 16, 1932 UNITED STATES PATENT OFFICE AND TELEGRAPH COMPANY, A CORPORATION OF NEW YORK SIGNALING APPARATUS ron. mooannw sYs'rEus Application filed December 12, 1980. Serial 1T0. 501,988.
This in'vention'relates to signalingand recording systems. More particularly, this invention relates to improvements in and additions to apparatus for recording messages which may be transmitted over a signaling circuit, such as a telephone line. Still more particularly, this invention relates to arrangements for indicating that recording eqluipment, which may be connected to a te ephone line, has been started in' operatlon and remainsin operation.
It is essential to an system for recording signals such as may e transmitted over a telephone line, that there-be means for indicating that the recording apparatus has been started in operation. It is also important for the persons taking part in a telephone conversation to know that the recording apparatus connected to their circuit remains in operation. Without such information a subscriber would be unaware that his statements are being at into permanent form and mi lit some ay be reproduced to confront h1m, to his detriment or damage. A
' subscriber having such knowledge would probably become more cautious andconserv- 'j ative withhis statements, as is generally the case-with a witness in court when his remarks are being recorded.
: therea mains in operation. This signal may be This invention is intended to provide a signal at'the instant recording apparatus is operatively connected to a telephone line. It is also intended to provide a similar signal at re ular and predetermined intervals r while the recording apparatus rerendered audible or'visible, as may be found desirable. Moreover, this signal may be transmitted to the called party or to the calling party or to a'telephone operator'or to any-two of these persons or all 'ofthem, and
this signal will be transmitted simultaneously to these persons.
One of the objects of this invention is to notif a. party to a telephone conversation that is conversation is being recorded.
Another of the objects of this invention is to apprise all the parties to a telephone conversation. that their conversation is being recorded.
Still another object of the invention is to provide an indicating signal at the begincARnoLL o. BICKELHAUPT, or NEW YORK, 1v. 1., Assreicon 'ro nmnrcm 'rnnnrnonn ning of the recording process and to transmit that signal to all the parties to a telephone conversation which is being recorded.
And a further object of this invention is to provide an-indicating si al not only at the beginning of the recor ing process but also at regular intervals thereafter throughout the recording process.
ltlghile this invention will be pointed out w1 it will be better understood, both as to its further objects and features, from the followin description, when read in connectionv wit theaccompany-ing drawings, in which Figure 1 shows schematically a telephone circuit equippedwith recording apparatus based on this invention, and F' 2 shows the details of the novel features the arrangement required to carry out the invention.-
Fig. 1 schematically shows one form of arrangement for recording a telephone conversation in accordance with the princi les of this invention. One telephone subscriber having a telephone substation set "designated elude, among other things, a telephone transmitter, a telephone receiver, and a ringer, and there may be similar equipment at the central oflice which maybe connected to the'line L. The equipment at the central ofli'ce may operate in response to signals from either of the stations T or T or this equipment ma be connected to the line L at the instance 0 the telephone operator at the central ofl'ice.
The reference character Q represents'a paratus for recording telephone signa This recording apparatus may be located at or near stations T or T or at or near the central ofiice CO. This recording apparatus may, of course,-be connected to the telephone line L whenever desired merely by .the closure of a switch W.
' Therecording apparatus Q may include,
particularity in the appended claims,
among other things, a revolving turntable or cylinder holder H (not shown in detail) which is, however, well known in the art. The rotating device may be coupled to a cam mechanism M and the cam mechanism may control a source of current which may be an alternating current generator G, the details of operation of one form of which will be described in greater detail hereinafter. The generator G may be one capable of producing current of any frequency, preferably an audible frequency suitable to effectively energize the telephone receiver or other electromagnetic device at the telephone substation sets T and T and the equivalent device at the central oflice CO. The generator G may, of course, be any form of electrical oscillator and it may be of the vacuum type, if desired.
Fig. 2 shows one form of arrangement for producing a tone signal suitable for transmission over line L. A cam M is mounted on a shaft S which is mechanically coupled to the revolving turntable or cylinder holder H, described in connection with Fig. 1 of the drawing. The cam M and the revolving device H may be connected directly, or indirectly through a geared train. Thus, the cam M will make a predetermined number of revolutions during each minute or during each interval of, for example, five minutes.
A metallic arm K will follow the outer surface of the cam M and during each complete revolution the arm K will make good electrical contact with another arm K for abrief space of time which may, for example, be several seconds. During this short interval, the arms K and K will be in circuit with each other through a pair of-metallic contacts N and N which are permanently connected to the arms K and K respectively. It will be obvious that the arm K is stationary and that the arm K is movable and, moreover, these arms may be brought into electrical contact with each other in any other well known manner. Furthermore, a bar of insulation I may, if desired, be placed between the arms K and K and it may be permanently fastened to either of these arms so that they may be maintained a predetermined distance apart, and this feature will be especially desirable if the arms K and K are equipped with contacts which are flexible.
The arm K is connected to a battery B, one terminal of which is grounded. The arm K is connected to the winding of a relay B, one terminal of which is also grounded. When the arm K is brought by cam M into the position shown in the drawings, it will make suitable contact with the arm K through the elements N and N and current will flow through the battery B, over contacts K and K and through the winding of the relay R, causing this relay to become operated.
The armature A of the relay R is permanently connected to an arm K and these elements always more in unison. lVhcnever the winding of the relay It becomes encr gized, the arm K will be brought into an electrical circuit with the arm K, through a pair of cohtacts designated 'N and N,. The fixed terminal of the armature A is connected to one side of, the line L, while the arm K is connected to one terminal of the alternating current generator (5?. The other terminal of the generator G is connected to the other side of the line L through a condenser C.
When the arms K and K are in circuit with each other, relay R will become operated and this relay will remain operated as long as these arms are so connected. During this period the generator G will send a pulse of alternating current over the arms K and K through the condenser C and over the line L. This pulse will be interrupted just as soon as the arms K and K are disconnected from each other. Shortly thereafter the cam M will again cause the arms K and K to make contact with each other and the generator G will then transmit another pulse of alternating current over the line L. Thus, the cam mechanism will cause pulses of alternating current to be transmitted over the line L and this will occur throughout the recording process. Inasmuch as the generator G produces an alternating current of a frequency within the range of audibility, the audible signal will be heard regularly and periodically at each electromagnetic receiver connected or otherwise coupled to the line L, and this signal will disappear when the recording mechanism ceases to function.
The relay R may assume any desired form. Its armature A may be equipped with a front contact which will become closed by the armature upon the operation of the relay. This front contact may extend to one terminal of the generator G and it will connect this generator to the line L through the series condenser C and the armature A. This construction will eliminate the arms K and K, as well as their associated contacts N and N The operating surface of the cam M has not been shown precisely in the shape it will have when used in carrying out the principles of this invention. This cam will have a surface which will quickly bring the arm K into circuit with the arm K immediately at the beginning of the recording process. The shape of the cam surface will also-be such that thearms K and K will remain in contact with each other for a predetermined interval of time so that a cleancut pulse of alternating current may be transmitted by the generator G over the line L. This cam mechanism will also be so arranged that the contacts K and K will be-positive-' 1y disconnected from each other after the cam M has ceased to revolvedisconnection of the generator from the line L after the recording process has stopped.
. While it has been clearly stated that the current of the generator G will operate electromagnetic receivers which may be connected or coupled to the line L and create audible signals in these receivers,it will be understood that visible signals may, if desired, beproduced. Those familiar with the art will real ize that transformers, tuned circuits, filters or the like may interconnect one or more lamps or other visible indicating devices to the line L so as to produce suitable visible signals. Of course, if visible signals are employed, the frequency of the current of the generator G will not have to be within the range of audibility- The generator G has been described as intermitently operated. If desired, the generator G may be continuously operated. This may be accomplished by rendering the surface of the device M circular and concentric with its shaft S so that the arms K and K will be in continuouscircuit through their contacts N and N while the recording apparatus remains in operation. As an alternative, the generator G may be maintained in continuous operation during the recording process bydirectly or indirectly coupling this generator to the revolving turntable or cylinder holder H of the recording apparatus.
It will be apparent that the generator G may be maintained continuously in operationdure ing the recording process in still other ways, all within the scope of this invention.
The generator G may be replaced by a phonographic device or reproducer which will be operated either intermittentlyor continuously during the recording process, as
desired. The record reproduced and transmitted over the line Lmay carry any predetermined signal, or any desired word, such as recorder or record or the like; or it may be any predetermined phrase or sen tence.
The generator G may be replaced by a modulator to which may be connected a plurality of generators or oscillators producing currents having different frequencies which, when modulated, form a background tone This will insure the amplitude, its amplitude being alternately increased or decreased.
This invention represents an innovation in the art of recording telephone messages. It permits recording operations to occur only with the knowledge of the persons engaged in the telephone conversation; The invention is intended to apprise the parties to the conversation that the recording rocess has started, and it continues to noti these parties at regular intervals or continually throughout the conversation.
While this invention has been shown anddescribed in certain particular arrangements merely for the purpose of illustration, it will be clearly understood that the general principles of this invention may be applied to other and widely varied organizations without departing from the spirit of the invention and the scope of the appended claims.
What is claimed is:
1. The method of apprising a party to a conversation that his conversation is being recorded, which consists in generating a char acteristic audible tone for transmission to said party and periodically reproducing that tone for said party "at regular intervals during the recording 0 eration.
2. The method 0 apprising a party to a telephone conversation that hls conversation is being recorded, which consists in transmitting to that party an audible tone at the be ginning of the recording process, periodicall reproducing that tone at regular intervals dining the recording process, and removing that tone at the end of the recording process.
3. The method of notifying a plurality of parties engaged in a telephone conversation that their conversation is being recorded, which consists in simultaneously transmitting to all of the parties an audible tone, and interrupting the tone transmitted to all" of said parties at regular-intervals of predeter- 'mined length.
4. The method of notifying a plurality of parties to a telephone conversation that their conversation. is being recorded, which consists in transmitting to all of the parties an' audible tone at the beginning of their recorded conversation and retransmitting the same p tone to all of said parties at-brief intervals throughout the recorded conversation.
'5. The method of apprising a party to a telephone conversation that h1s speech is be ing recorded, which consists in producing and transmitting a characteristic phonographic tone to said party and reproducing and retransmitting that phonographic tone to said party at brief regular intervalsthroughout the recording process.
6. The method of operating. record ng equipment with the knowledge of a plurality of parties whose conversation is being recorded, which consists in transmittmg an mdicating signal to all of said parties at the beginning of the recording process and at brief regular intervals thereafter during the recording process.
7. The combination of a telephone line, recording apparatus connected to said line, and cam-operated means controlled by the recording apparatus for indicating that the recording apparatus has started to record messages transmitted over said line.
8. Apparatus for recording signals transmitted over a telephone line, including means for indicating that the recording apparatus has started in operation, and automatic means for periodically indicating at regular intervals that the recording apparatus re mains in operation.
9. Apparatus for recording signals transmitted over a telephone line, including automatic means for indicating at predetermined regular intervals that the signals are being recorded.
10. The combination of a circuit over which signals may be transmitted, recording apparatus coupled to said circuit, a source of alternating current controlled by the recording apparatus and connected to said circuit, and automatic means for periodically interrupting the flow of current from said source over said circuit at regular intervals.
11. The combination of recording apparatus. cam mechanism controlled by said recording apparatus, means for producing tone signals, and means controlled by said cam mechanism for periodically interrupting the tone signals.
12. A signal system comprising a line, a tone generator, recording apparatus, and means controlled by said recording apparatus for connecting said tone generator to said line at regular and predetermined intervals.
13. The combination of recording apparatus a generator of current of an audible frequency, and cam-operated means controlled by said recording apparatus for periodically interrupting the current of said generator, said cam-operated means coupling said generator to said recording apparatus.
14:. The combination of a telephone line, recording apparatus connected to said line and having a revolving member, an alternating current generator, and cam controlled means responsive to the action of the revolving member of said recording apparatus to connect said generator to said line.
15. The combination of a telephone line, a plurality of telephone substation sets connected to said line, each having a telephone receiver, recording apparatus connected to said line, said recording apparatus having a revolving member, an alternating current generator having a frequency audible inthe telephone receivers of the substation sets, and cam mechanism controlled by the revolving member of the recording apparatus to connect the generator to said line.
16. The combination of a telephone line, recording apparatus connected to said line, and means controlled by said recording apparatus for producing a back-ground tone for transmission over said line continuously during the operation of said recording apparatus.
17. The combination of a telephone line means for recording the messages trans mitted over said line, means for producing a back-ground tone of predetermined characteristics, and automatic means for transmitting said back-ground tone over said line at regular intervals during the time the recording means is in operation.
18. The method of recording a telephone conversation with the knowledge of the party engaged in the conversation which consists in producing a characteristic back-ground tone of predetermined characteristics and transmitting that tone at regular intervals throughout the conversation.
In testimony whereof, I have signed my name to this specification this eleventh day of December, 1930.
CARROLL, O. BIGKELHAUPT.
US501988A 1930-12-12 1930-12-12 Signaling apparatus for recording systems Expired - Lifetime US1845034A (en)

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2502123A (en) * 1946-03-06 1950-03-28 Union Switch & Signal Co Railway train communication apparatus
US2503176A (en) * 1946-10-31 1950-04-04 Edison Inc Thomas A Signaling means for telephone recording apparatus
US2528459A (en) * 1946-09-06 1950-10-31 Soundscriber Corp Apparatus for indicating that telephone conversation is being recorded
US2530075A (en) * 1948-11-12 1950-11-14 Automatic Elect Lab Signal unit for telephone conversation recorders
US2529636A (en) * 1949-09-09 1950-11-14 Daven Company Recorder-connector for use in telephone conversation recording
US2531203A (en) * 1947-12-09 1950-11-21 Bell Telephone Labor Inc Telephone substation coupler for conversation recording
US2539139A (en) * 1949-07-14 1951-01-23 Jordaphone Corp Of America Telephone system for automatic answering, recording messages, and recording normal conversations
US2558040A (en) * 1945-04-05 1951-06-26 Carter Norman Edward Wilson Telephone message recording device
US2673241A (en) * 1948-06-02 1954-03-23 Telephone Answering And Record Telephone answering and recording device
US2673242A (en) * 1949-12-17 1954-03-23 Telephone Answering And Record Means for controlling telephone answering devices
US2713088A (en) * 1949-12-17 1955-07-12 Telephone Answering And Record Telephone answering and recording device
US2793251A (en) * 1952-04-02 1957-05-21 Telephone Answering And Record Signalling apparatus
US2800530A (en) * 1949-12-17 1957-07-23 Telephone Answering And Record Telephone answering and recording devices

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2558040A (en) * 1945-04-05 1951-06-26 Carter Norman Edward Wilson Telephone message recording device
US2502123A (en) * 1946-03-06 1950-03-28 Union Switch & Signal Co Railway train communication apparatus
US2528459A (en) * 1946-09-06 1950-10-31 Soundscriber Corp Apparatus for indicating that telephone conversation is being recorded
US2503176A (en) * 1946-10-31 1950-04-04 Edison Inc Thomas A Signaling means for telephone recording apparatus
US2531203A (en) * 1947-12-09 1950-11-21 Bell Telephone Labor Inc Telephone substation coupler for conversation recording
US2673241A (en) * 1948-06-02 1954-03-23 Telephone Answering And Record Telephone answering and recording device
US2530075A (en) * 1948-11-12 1950-11-14 Automatic Elect Lab Signal unit for telephone conversation recorders
US2539139A (en) * 1949-07-14 1951-01-23 Jordaphone Corp Of America Telephone system for automatic answering, recording messages, and recording normal conversations
US2529636A (en) * 1949-09-09 1950-11-14 Daven Company Recorder-connector for use in telephone conversation recording
US2673242A (en) * 1949-12-17 1954-03-23 Telephone Answering And Record Means for controlling telephone answering devices
US2713088A (en) * 1949-12-17 1955-07-12 Telephone Answering And Record Telephone answering and recording device
US2800530A (en) * 1949-12-17 1957-07-23 Telephone Answering And Record Telephone answering and recording devices
US2793251A (en) * 1952-04-02 1957-05-21 Telephone Answering And Record Signalling apparatus

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