Patent GB-497636-A (GB)
Title: Improvements in apparatus for recording and reproducing telephone messages
IPC: H04M1/65
Filed: 1937-03-17
Abstract: 497,636. Sound recording and reproducing apparatus. SOUKUP, J., ZERNER, F., HOLMES, A., and WARMAN, W. H. March 17, 1937, No. 4948. [Class 40 (ii)] [Also in Group XXXIX] In a system for recording incoming telephone messages mechanically or magnetically in a number of parallel tracks in the absence of the subscriber, a single control handle is provided for connecting the system to the telephone line and for effecting all the necessary mechanical and electrical changes whereby the recording and reproducing device or devices and the record carrier are brought automatically into the correct relative positions for recording and for reproducing the earliest recorded message not previously reproduced. The handle may also modify the effective stylus pressure when the same instrument is used for recording and reproducing. When magnetic recording is used, a number of magnetic wires may be carried by a non-magnetic ribbon. In modified systems in which messages are recorded in a single track the records are erased after reproduction before or during the next recording period. The invention is described with reference to a system in which the messages are recorded mechanically in parallel tracks on one or more tapes and to telegraphone systems. In both systems the same or separate instruments may be used for recording and reproducing and in the latter case the relative positions of the instrument may control the driving motor. The control handle may be locked in any position until the operation that it initiated in that position has been completed. A predetermined length of record may be allotted to each call or an indefinite length may be allowed. Specifications 490,825, [Group XXXIX], and 490,826 are referred to. The following conventions are used in the drawings. References beginning with the letters u, m, c denote that the parts in question are controlled respectively by the main control handle, the motor and one of the counting or measuring devices for registering the number of calls recorded and reproduced or measuring the amount of record material recorded and reproduced. A ring round a reference means that the part concerned is operated by means of a push button. Roman and Arabic numerals used in Figs. 13a and 14 (Comp.) to indicate the different stages in the working of the apparatus are shown adjacent certain contacts to show that in the stage indicated the contacts concerned are in the condition other than that shown in the drawing. In some cases the particular one of the counting devices that controls a c contact is indicated on the drawing. Circuit arrangements for parallel-track system, Fig. 1 (Prov.). On the arrival of a call with the switch U set to record messages, H energizes HA which locks and connects the mains to motor M. When a predetermined speed is reached, contact g1 is operated and in due course cam operated contacts m2 .. m5 loop the line and extend it to the recording apparatus after giving to the calling subscriber an appropriate verbal message from a pick-up Q and sound signals from a siren S. After the tape has been run off, it and the recorder are moved into position for the next message, and the motor unlocks HA at m1 and then stops. When all the recording tape is used up, c7 disconnects the apparatus from the supply. In some cases HA may be omitted. With switch U set to reproduce messages, the reproducing device is set to the beginning of the first of the records not previously reproduced, contacts u3, u4 are closed and, after a delay to allow the amplifier valves to warm up, thermal relay Z switches on the motor. At the end of the last record, the circuit to the mains is opened by c6 which is controlled by a counter which is stepped in one direction by a magnet 65 each time contacts mII are actuated during recording and in the opposite direction by a magnet 66 which is similarly controlled during reproduction. Contact mII is actuated by a wheel 28, Fig. 2 (Prov.), which is moved laterally during repeated reproduction, as described below, and then does not actuate this contact. In a modified system, Fig. 1 (Comp.) (not shown), the delay switch is omitted, the motor being switched on for reproduction by a relay in one of the amplifier anode circuits, and a manual switch, which may be linked with the switch hook, is provided in the motor circuit. Other modifications of detail are shown in this system. Control of tape drive and sound-box traversing for parallel-track system. In one arrangement, Figs. 2 .. 6 (Prov.), shaft 1 is coupled by the main control handle to one or other of two shafts 2, 61 which are driven by the motor at different speeds. One or other of the cams 3, 4 then engages a slide 5 which controls two scissors-like clutches to cause one of two spools 19, 20 to be driven by the roller 18 and wind the tape off the other over a pulley 21 which supports the recording and reproducing device. The latter has separate cutting and reproducing needles 22, 62 one or other of which is operative, according to the position of the pulley which is moved by handle U. The pulley is moved to disengage the cutting stylus by a link 24 connected to the left hand clutch. The cams are so arranged that after the tape has been run-on to 20 during recording it is transferred to 19 and the sound box is shifted laterally in readiness for the recording of the next message. Apparatus for effecting this is shown in Fig. 2 (Prov.). The shaft 26 of the spool 19 drives a pin disc 31 which drives a Geneva wheel 33 coupled under control of the handle U to a threaded spindle 36. The latter by means of a nut 41 controls the lateral position of the recording &c. device. When the shaft 26 is driven in the reverse direction, a spring 30 is allowed by a lever 42 controlled by a cam 43, driven by the slide 5 to force the pin wheel to the left out of engagement with the wheel 33. The Geneva wheel is then locked by a cylindrical extension of the pin disc. The traversing device is disabled when repeated reproduction of a particular record is required by means of a button 63, which moves the cam 43 clear of the lever 42. The shaft 36 is geared to a spring barrel 47. During recording, the control handle U holds a loose disc 49 so that a pin 51 projecting from it is in one (in the case of a new blank, the first) of a series of holes 53 in an axially movable but non- rotatable plate 52. As the spring barrel is wound up by the arrival of each message, a projection 56 on it recedes from a projection 54 on the disc. In the position of the control handle U between " recording and " reproducing " the spindle 36 is disengaged from the Geneva wheel and the spring then restores the barrel until the stops 54, 56 are in engagement, driving the shaft 36 to bring the sound box over the first trace. During reproduction, a pin 50 couples the disc 49 which is disengaged from the plate 52 to the spring barrel and accordingly, when the handle U is again moved to " recording, " pin 51 enters one of the intermediate holes 53 and the sound box remains in its intermediate position. Subsequent records cause the separation of the stops 54, 56, and preparation for "reproduction " brings these stops into engagement again and causes the soundbox to move to the first of the recently recorded messages. When a new blank is put in, the spring barrel carries the disc back to the position shown in which stop 55 engages stop 57. When the handle is in the recording position, the angular distance between the stops 54, 56 indicates the number of records made and not yet reproduced and that between the stops 56 and 57 indicates the total number of records made. When the blank is full, contacts c7 put the apparatus out of action. The reversing clutch may be controlled electrically from the tape as well as mechanically from the motor. In a modified driving arrangement, Fig. 2 (Comp.), the control shaft 1 carries a disc with pins 86, 87 which engage members 82, 83 on a forklike lever 78. Movement of the fork in one direction tilts a lever 5a and brings a coupling roller 16 into engagement with the spool 20, and driving member 18. Movement in the other direction couples the other spool. The lever 78 on operation snaps past a notch in the armature of a magnet MG so that the spool remains coupled until the magnet is energized via a contact carried by the record strip. To avoid energization of MG after the strip has stopped, its circuit also includes contacts which are closed only while the coupling lever 5a is tilted. Preferably the spools are braked to avoid over-running. An arrangement is referred to in which one spool is driven by the motor and the other by a spring. In a modified control and sound-box traversing arrangement, Figs. 3 .. 5 (Comp.), a snail 136 operated step by step by a magnet 165 by the momentary operation of contact cIIA after the making or reproducing of each record is engaged by a member controlling the position of the recorder-pick-up. During recording, the driving pawl u12 also drives a disc 92 which carries contacts c6 co-operating with a separating piece 172 on the snail, and the contacts b, a of switch u11 are together. To restore the recorder-pick-up to its initial position the pawl is moved so that it engages only the snail-driving ratchet and the springs b, c of switch u11 are brought together. The pawl is then operated in a self-interrupting circuit until springs 157 are opened. The position at which this occurs is determined by the position to which these springs, which are carried by a further disc, have been rotated during the previous reproducing period, if any, during which this disc was stepped with the snail. During reproduction 92 remains stationary and consequently contact c6 is opened when all the messages recorded have been reproduced. Repeated reproduction is given by opening contact 163 by a push button. When several record blanks are to be used, the snail may be given s