US1670461A - Signaling system - Google Patents

Signaling system Download PDF

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Publication number
US1670461A
US1670461A US123328A US12332826A US1670461A US 1670461 A US1670461 A US 1670461A US 123328 A US123328 A US 123328A US 12332826 A US12332826 A US 12332826A US 1670461 A US1670461 A US 1670461A
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US
United States
Prior art keywords
station
distributor
sending
relay
correcting
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US123328A
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English (en)
Inventor
George A Locke
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Priority to US123328A priority Critical patent/US1670461A/en
Priority to DEE35911D priority patent/DE545103C/de
Application granted granted Critical
Publication of US1670461A publication Critical patent/US1670461A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/14—Two-way operation using the same type of signal, i.e. duplex
    • H04L5/18—Automatic changing of the traffic direction

Definitions

  • This invention relates to signaling systems and more particularly to printing telegraph systems employing long submarine cables.
  • Its rincipal object is toy improve the metho and means for synchronizing the transmitting and receiving mechanisms in p systems of this type.
  • the mecht anisms for transmitting and receiving may consist of so-called distributors comprising transmitting rings, receiving rings, and correcting rings.
  • the correcting rings at each station being used for maintaining synchronism between the distributor at that end of the cable and the signals transmitted from the opposite end of the cable.
  • the present invention is applicable to systems of this general character and comprises means including the correcting ring of the distributor at one end of the cable orientable in relation to the associated transmitting ring whereby the system may be adjusted, before the actual transmission of messages begins, to maintain synchronismduring successive reversals of the direction of transmission.
  • different amounts of time lag due to the transmission characteristic of the cable may be compensated for and the tendency on the part of the sending and receiving distributors to fall out of synchronism, during the intervals when the reversals of direction of transmission take place, is overcome.
  • a multiplex printing telegraph system which includes a terminal station, a land line, a repeater station, a submarine cable, and another terminal station in series.
  • Fig. 1 represents one terminalstation with its transmitting and receiving equipment indicated in a schematic form and the speed correcting mechanism shown in detail.
  • Fig. 2 represcnts the repeater station connected to the land line from thc-station shown in Fig. 1 and to the submarine cable leading to the terminal station shown in Fig. 3.
  • Fig. 3 shows in schematic form the transmitting and receiving equipment at the terminal station connected to the submarine cable incoming from the repeater station. The correcting mechanism in this figure is shown in detail.
  • the invention relates principally to a method and means for synchronizing the operations of the distributors at the various stations, such parts of the system as are not directly concerned with this problem have been shown in a highly schematic form.
  • the speed correcting or synchronizing means at the terminal stations have been shown in considerable detail.
  • a transmitting distributor 1 with its associated impulse transmitting device 2 and a receiving distributor 3 with its printing devices 4. are shown connected to contacts actuated by cam 5 which, under the control of a direction control apparatus (not shown) is adapted to alternately connect said distributors to a land line 6.
  • Corrector distributor rings 8 for station A are shown with their associated brush 9, a corrector line relay 10 controlled by impulses from station B over line 12. and an auxiliary corrector relay 14 controlled from the corrector rings 8.
  • the corrector mechanism 20 is for producing angular shifts of the brushes traveling over the faces of the-correcting, transmitting and receiving distributor rings. This corrector mechanism is located between the motor for driving the distributors and the distributors themselves. The motor has not been shown.
  • the shaft 22 is driven by the motor and the shaft 23 drives the arms on which the brushes, such as'9, for the distributors are mounted. These arms are arranged to drive the brushes over the various distributor faces in a manner well known in the art.
  • the corrector mechanism 20 consists ot differential beveled gear arrangement. 25 interposed between the motor shaft 22 and the brush shaft 23 and the gears that link these two shafts together are mounted on a supporting frame 27 secured to a worm pinion 28 that meshes with a worm 29. Any change in the angular position of the worm pinion 28 changes the angular position of the linking gears and this in turn changes the angular position of the brush shaft 23 with respect to the motor shaft 22.
  • the worm 29 is rotatable to shift the angular osition of the worm pinion a small angle y means of corrector magnets 31 and 32 in one direction or the other.
  • the ratchet wheel and pawl mechanisms 35 and 36, respectively, are operated by these magnets so that on the operation of either one of the magnets, an angular shift of the distributor brushes in one direction or the other is effective.
  • a separate ratchet wheel 37 and a pawl 38 is provided in order to hold the worm 29 firmly while the magnets are not rotating it. This wheel and pawl also limits the movement of the worm 29 to one step each time a corrector magnet operates.
  • the automatic corrector mechanism 20 is therefore capable ol shifting the brushes of the distributors in a forward or in a backward direct-ion; magnet 31 being provided for shifting it in a forward direction and magnet 32 for shifting it in ay backward direction.
  • forward is meant a shift in the same direction as the rotation of the brushes; by backward is meant a shift oposite to the direction of the rotation of the rushes. It is seen ⁇ therefore. that by this mechanism, corrections in either direction can be effected while the distributor brushes are being rotated by the motor and hence synchronizing effects may be produced between the brushes of the distributors at different stations as will be hereinafter more fully explained.
  • a correction direction key 40 is provided to connect one corrector magnet or the other with the circuit controlled by the auxiliary corrector relay 14 which in turn is under control of the corrector rings 8 and brush 9.
  • the equipment at the repeater station B comprises a receiving distributor 100 and its associated storing relays 101 from which the signals are retransmitted through the transmitting distributor 102 to the submarine cable 103 leading to the terminal station C.
  • the cams 104 for controlling contacts to switch from reception to transmission and vice versa, have been shown.
  • signals received from line 6 are repeated to cable 103 through the receiving distributor 100, storing relays 101, transmitting distributor 102 ⁇ While the signals from the submarine cable 103 are in synchronism with the distributors at station A by means of a distributor arrangement 18 at station A whereby impulses are sent over a .separate line 16 between these stations to the driving motor arrangement at station B.
  • the submarine cable 103 terminates at station C at which the equipment for receiving signals consists of the amplifier apparatus 300, line relay 301, receiving distributor 302 and the printing apparatus 303.
  • the correction control relay 304 is in series with the line relay 301 to control the corrector line relay 306 which in turn controls the application of correcting impulses through the corrector rings 310
  • This mechanism 313 is identical with the corresponding mechanism 20 at station A. and the magnet 314 is provided for forward correction while the magnet 315 is rovided for backward correction.
  • the dlrection correction key is marked 310.
  • stations A and B may be regarded as'a unit and station C as a separate unit bctwen which units synchronism must be maintained by means of signals transmitted over the cable 103.
  • The. knurled handle 350 is provided on the shaft 341 for manually adjusting the s vstem in order to set it to a synchronous condition.
  • Relay 306 also reverses the position of its armature in response to each reversal of current in its winding and successively charges condenser 336, from a source of positive potential shown, and discharges it through the main ring 346 on a distributor 310, a brush 337 to segments As long as the distributor at station C is in proper phase relation with respect to the received Signals the brush 337 will be onone of the segments 345 at the time relay 306 reverses the position of its armature and the con- .denser 336 will be discharged through the negative battery shown connected to segments 335 and no correction will be produced. 4The distributorl at station C, however, isset to run at a speed slightly lower than that of the distributor at station A.
  • the brush 337 will be constantly shifting back and eventually will be resting yon one ofthe segments 345 at the time relay 346 reverses the) position of its armature.
  • the charge from condenser 336 will be applied through the brush 337 and a segment 345 to the right hand winding of relay 339 and through the back contact and armature of ma net 314 to negative battery 'at key 316.
  • Th1s causes the armature of relay 339 to shift to the position opposite that shown in the drawing which applies positive battery over the armature of relay 339 through the winding of magnet 314 to negative ybattery at key 316.
  • Thistiming device is merely a means for actuatlng the above mentioned cams at certain intervals to make them perform thisl cams atall three stations are controlled to perform their switching operations substantially simultaneously with due regard tolag
  • Cam 5 causes the contacts to open the connections between the sending distributor 1 and the line 6 and to close a connection between the receiving distributor 3 and the line 6.
  • the cam 104 opens the connection to the receiving distributor 100 from line 6 and closes a connectionv from line 6 to the armature of line relay 106.
  • One of the cams 104 also closes a circuit for the operation of relay 112 to open the connection between the submarine cable 103 and the sending distributor 102 and close a connection between this cable and the amplifying device 105.
  • Relay 10 in operating closes a circuit for the operation of auxiliary corrector relay 14 through brush 9, provided brush 9 has advanced out of synchronism with the brushes of the sending distributor 321. If this is the case circuits will be completed from one side of the condenser44, which previously has been charged through the circuit completed at the right-hand contact and ture of magnet 32 through negative battery to ground. This latter circuit causes the auxiliary corrector relay 14 to actuate its armature to a position opposite to that shown in the drawing.
  • a circuit is thereby completed as follows: from battery, through the winding of magnet 32, left-hand closed contacts ot direction key 40, armature and contact of the auxiliary corrector relay 14 to ground. Magnet 32 in operating actuates the pawl and ratchet mechanism 36 to shift through the corrector mechanism 20 the Shaft 23 for a small angulardistance in a. backward direction in relation to the rotation ot' the shafts 22 and 23. On the operation ot' magnet 32 the circuit through the right-hand winding of auxiliary corrector re ay 14 is.
  • the correcting segments 1n Fig. 4 are hereafter called black segments.
  • the sending brush 401 sweeps from left to right over the sending segments 400 and impulses, such as 402, will therefore be sent to station C.
  • impulses are for the sake of convenience assumed to consist of successive impulses of opposite. polarity, although iu actual practice they may consist of a plurality of impulses of one polarity followed by a plurality of impulses ot the opposite polarity.
  • An impulse interval is represented as occupying space or time, that is, a segment swept over by the brush 401 or the time required for such movement.
  • the received impulses 405 come in later in time due to the lag in transmission.
  • this lag is due to the transmission characteristics of the several circuit elements, such for example, as the line 6, submarine cable 103. amplifier 300, relay 301, etc. It is assumed that the system has already been phased or lined up to compensate for this lag.
  • brush 401 is at the center of the sending segment as shown at 401', brush 406 has not yet reached the center of the receiving segment, but will reach it at a time later (equal to the line lag) when the center of the signal impulse arrives.
  • the receiving segments are made shorter than the sending segments in order that the, central portion of the received signal will be effective for operating the printing relay.
  • Corrector brush 408 is shown in line with receiving brush 406, but in practice it should be understood that the receiving brush may be oriented without disturbing the 'corrector brush.
  • the receiving segments 407 have been phased to receive approximately the middle of the signal impulses 405-and the corrector rings 409 have such a relation to the point of the beginning of the impulses 405 that no corrections will occur as these impulses begin because the corrector brush 40S is ou the left hand end of a non-correcting,r segment of the group 405).
  • the uou-correetiug segments are hereinafter called white segments.
  • the received impulsos 413 come in at station A with an assumed line lag of half the distance between the beginning of two succeeding impulses sent out from station C. Since it is assumed that the system is also already phased or lined up for reception of impulses in this direction, it follows that when the brush 411 travels from the beginning of a sending segment of ring 410 as shown in the drawing the receiving brush 414 will arrive at the positions shown in the drawing when the lmpulse 413 arrives. Here also the receiving segments 415 are shortened and phased to receive only the middle portion of the impulses.
  • the correcting segments 417 were not properly set with respect to the sending segi ments 400.
  • the correcting brush 416 were on the right end of a black or correcting segment instead of the right end of a white segment where it should have been.
  • the correcting mechanism at sta,- tion A was thereupon actuated to correct all the brushes at station A backward the width of a correcting segment (which is half the width of a sending segment). This displaced the sending brush 401 to the position 401 (assuming that it was formerly at position 4012). Therefore, when station A again transmits, the first impulse w1ll be transmitted from station A and received at q f station C at a corresponding portion of time later thanthe previous time.
  • the position of the impulses from station A in their relation in time to impulses 402 is indicated with a dotted impulse curve 420 and the arrival of the impulses at stat-ion C in this relationy in time to impulses 405 is indicated by dotted impulse curve 421.
  • the first impulse would be received on the first receiving segment of ring 407 and the second impulse would also come on the first receiving segment and the system would be out of line. 1t will be noted that the system would remain out of line as the beginning of the impulses would take place while the correcting brush 408 travels over a white segment of ring 409. This may be verified by the d otted vertical line projected from the beginning of an impulse 421 to a white seg ment of ring 409.
  • the system may get out of synchronism even though the motors at the two stations are running at exactly the same speed.
  • the motor at station A is running faster than the motor at station C. This requires a forward correction of the brushes at station C in the manner previously described to maintain synchronism While station A is sending, and a backward correction of the brushes at station A when station C is sending. Therefore, during the change over or switching period when no impulses are transmitted over the cable and consequently no correction can take place the brushes at station A gain in speed andthe brushes at station C lose in speed so that when transmission again begins a few correcting steps are normally required to bring the system back into synchronism.
  • the proper orientation of the ring 417 may be determined by observing the number of corrections that take place to bring the system toward synchronism at the receiving station after a reversal of direction of transmission has occurred. If the number of steps which occur are just the number re- 401 during a changeover interval, then the orientation of the ring segments 417 is cor rect. If it is different, the roper orientation change can be determined, from the amount of the difference, from the fact that üd to correct for gain or loss of brushl the number is greater or less than it should be and from the further fact that the distributors do or do not get out of. phase on successive transmissions in the same direction.
  • a synchronous telegraph system a plurality of stations, distributors at .said st ations, a transmission line connecting said stations, means for automatically reversing the direction of transmission from time to time, synchronizing means for said distributors controlled by the distributors at the station which is sending, means for chang ing the relative positions of the sending segments and the correcting segments at one of said stations whereby the system may be adjusted to maintain synchronism during successive reversals of the direction of transmission.
  • a synchronous telegraph system a plurality of stations, sending and receiving distributors at each station, a correcting distributor at each station, a transmission line connecting said stations, means for automatically reversing tbe direction of transmission from time to time, synchronizing means for said distributors comprising means at each station for synchronizing distributors at the station receiving with a distributor at the station sending including the correcting distributor at the station receiving, and means for changing the relative positions of the sending distributor and the correcting distributor at one station to maintain synchronism between the distributor at said stations during successive reversals of the direction of transmission.
  • a synchronous telegraph system two stations, sending, receiving and correcting distributors at each station, a transmission line connecting said stations, means for automatically reversing the direction of transmission at pi'edetermined regular intervals, synchronizing means ior the brushes on said distributor comprising automatic means for synchronizing the brushes of one station with a speed at the other station characterized in this, that the s eed of the brushes of the distributors of tie receiving station is svnchronized to the speed of the brushes ol the distributors of the sending station in a system where the normal speed of the brushes of one station is faster than the normal speed of the brushes at the other station, and means for orientating the distributor at one station to a certain relation to the position of the sending distributor at this station whereby the synchronizing means is controlled to reestablish synchronism between tlie brushes of the distributors at the two stations it' the brushes get out of synehronism during the successive reversals of direction of transmission due to the diier ence in speed of the brushes at

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Motor Or Generator Current Collectors (AREA)
  • Control Of Multiple Motors (AREA)
US123328A 1926-07-19 1926-07-19 Signaling system Expired - Lifetime US1670461A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US123328A US1670461A (en) 1926-07-19 1926-07-19 Signaling system
DEE35911D DE545103C (de) 1926-07-19 1927-07-06 Telegraphensystem mit umlaufenden Verteilern

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US123328A US1670461A (en) 1926-07-19 1926-07-19 Signaling system
GB16357/27A GB297696A (en) 1927-06-20 1927-06-20 Improvements in synchronising means for printing and like telegraphs

Publications (1)

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US1670461A true US1670461A (en) 1928-05-22

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US123328A Expired - Lifetime US1670461A (en) 1926-07-19 1926-07-19 Signaling system

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US (1) US1670461A (de)
DE (1) DE545103C (de)
FR (1) FR637456A (de)
GB (1) GB297696A (de)

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Publication number Publication date
FR637456A (fr) 1928-05-01
GB297696A (en) 1928-09-20
DE545103C (de) 1932-03-02

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