Patent GB-147291-A (GB)
Title: A talking machine
IPC: G11B17/26
Filed: 1919-04-17
Abstract: 147291. Tidswell, H. R April 17, 1919. Multiple; starting and stopping; returning sound-box to starting point; turntables; tone-arm joints; disk records.-In a multiple phonograph, any record can be selected by means of the switch shown in Fig. 1 or alternatively by a pressbutton. Records are then automatically transferred by carrierbelts from a pile on the turntable to an auxiliary support, or vice versa, until the required record is uppermost on the turntable. The tone-arm is then automatically lowered and the record is played. The plugs 4, Fig. 1, each correspond to a record, and they are normally held against removal by collars 33 engaged by the disk 8. To select a record, the knob 5, Fig. 1, is turned until the pointer 6 is opposite to the corresponding plug 4, and a notch in the circumference of the disk 8 then permits this plug to be withdrawn. The corresponding spring 20 snaps on to the pin 30, locking the disk 8 against further rotation and energizing the corresponding magnet 65, Figs. 7 and 11, which ultimately selects the record. The plug 4 is then inserted in the spindle 7, which' it depresses against the resistance of the spring 36 until the switches 25, 26 are closed. When the knob 5 has been turned, it is prevented from being turned in the reverse direction by a pivoted triangle 29, until this triangle has been re-set by the forked rod 10 actuated by the cone 11 when the spindle 7 is depressed. The switch 25, Figs. 1 and 11, energizes the solenoid 23 so that its spring-controlled plunger 21 locks the spindle 7 in position. The rod 12 rotating with the knob 5 has closed a switch 43 or 44, Figs. 1 and 11, according to the direction in which the knob was turned; hence the switch 26, Fig. 11, energizes one or other of two sets of magnets, viz. 77, 150, 58, or 78, 151, 57, according as the record required is to be found on the support 52 or the turntable 51, Fig. 7. These parts 51 and 52 are balanced on a beam 55. The following description applies to the case where the required record is to be found on the turntable. If the magnet 57 be energized as above, the support 52 falls slightly, the stop 67 on the cylinder 62 (which is incapable of rotation) being checked by one of a spiral series of steps 71 cut in the cylinder 62 (which is capable of rotation only). The top record closes the switch 94, Figs. 7 and 11, and thereby causes the magnet 152 to move the commutator 153 one step through a pawl-and-ratchet mechanism. The circuit of the motor 79 is thus closed through the brush 154, and since the magnet 151 is active as described above, the motor revolves in the direction which causes the chains 90, 91, Fig. 9, to carry the top record of the turntable 51 on to the support 52. The chains are provided with grips 88, 89, each consisting of a bent lever, Fig. 10, the short arm of which is pressed back by the edge of the record so as to cause a rubber pad on the longer arm to grip the record. The records are ultimately positioned on the tables 51, 52, by rods 115 which are raised by levers 114 when the tone-arm descends as described below. The backs of the records may be covered with baize which does not extend quite to the edge, or the edge may be shaped as shown in Fig. 10<a> to facilitate picking up. Alternatively, sheet-metal cases, Figs. 16 and 17, may contain the records which are placed in the cavities 192, a baize backing and a guiding groove for the needle being provided. The commutator 153 also closes through a brush 163 the circuit of a magnet 72, withdrawing its forked plunger 74. When the travelling record reaches the support 52, it closes the switch 95, rotating the commutator 153 another step and breaking the circuits of the motor 79 and magnet 72. The plunger 74 is thereupon pulled forward by a spring, and as the pawl 76 is held out of engagement by the magnet 78, the pawl 75 moves the wheel 96 one step, thus rotating the shaft which carries the cylinders 68, 69, Fig. 7. The cylinder 62 and shaft 54 are thus enabled to fall a further step under the influence of the magnet 57. This cycle of operations repeats itself until a hole 63 comes opposite to that one of the magnets 65 which is energized (corresponding to the record required). The plunger 64 then enters the hole and the turntable is locked in position. The circuits operating the transfer of records are thereupon cut at 99<a> by the movement of the tone-arm, described below. Movements of tone-arm. The tone-arm is jointed, as shown in Fig. 6, and is carried by a swivelling plunger 103, Fig. 3, which has guidearms 104 moving in triangular guide-slots 105 in the cylindrical casing 117. The arms 107, 108, and an arm 99 at right-angles to these periodically make circuit with electric contacts so arranged as to carry through the cycle of movements of the reproducer. A dash-pot 112 is provided. The raising of the tone-arm is effected by the electromagnet 109. During the transference of records the circuit of this magnet is broken at 159 owing to the energization of the magnet 158. The circuit of the latter is at this time closed through the arm 107, which is retained in its rest-position 107<b>, Fig. 11, 'by a one-way catch. The circuit also passes through a series of switches 162, one of which is broken by one of the plungers 64 when the selected record is reached. A parallel switch 164, however, maintains the circuit until it is opened by the conveyer chain 90. The magnet 158 then permits the magnet 109 to be energised, and the tone arm is raised. The arm 99 breaks the record-shifting circuits at 99<a>, and the arm 107 on reaching the position 107<c> re-energizes the magnet 158 so that the tone-arm guides 104, Fig. 3, can slide down the sloping part of the guide-slot, the circuit of the magnet 109 being thereafter kept open by the arm 108 leaving the contact E. This arm 108 then energizes the magnet 160 through the contact F, and so starts the motor 61 which turns the turntable 51. During performance, the arm 108 travels horizontally until it again reaches the contact E, when the magnet 109 is energized and the tone-arm rises. Before coming to rest in position 107b, the arm 107 passes through the position 107<a> where it energizes the magnet 156 which breaks the circuit of the magnet 23, permitting the spring-actuated withdrawal of the plunger 21, Fig. 1, so that the spindle 7 rises and the plug 4 can be removed. Alternative method of selecting records, Figs. 12 and 13. The selector shown in Fig. 1 is replaced by a set of push switches 186, one for each record. Each switch when operated enlivens, through brushes 174 and slip-rings 173, a contact 189 on a cylinder 171 which can rotate but not rise or fall. Each contact, when its corresponding record is in playing position, makes circuit with a brush 190 carried by the stem 54 of the auxiliary record-carrier 52. <A> stud 170 on the same stem 54 engages in steps 176 in the cylinder 171, each step corresponding to a contact 189 and to a record. A brush 179 on the cylinder is connected to the tone-arm contact shown at 99<a>. This brush contacts with one or other of the halfrings 177, 178, and so energizes either the magnets 57, 151 or the magnets 58, 150, of which 57, 58 tend to raise or depress the turntable, while 151, 150 determine the direction of the recordtransferring motor 79. During transference of records, the tone-arm contact 107 is at 107<b>, so that when one of the switches 94 and 95 is closed bv a rising record and the magnet 152 acts to turn the ratchet 153 one step, current is admitted to the brush 153. The magnet 184 is thereby energized and breaks at 187 the circuit of the tonearm-lifting solenoid 109, and at the same time the magnet 72 retracts the pawl 200, and the motor 79 also starts transferring a record. The record on arrival closes the other switch 95 or 94, thus turning the ratchet 153 another step so that the magnet 72 is de-energized, and the magnet 180 rotates the ratchet 96 through one step by the pawl 200, together with the cylinder 171. The stem 54 of the record-carrier 52 is thus enabled to rise or fall one step, and the cycle is repeated until a live contact 189 corresponding with the desired record comes to the brush 190, whereupon the magnet 181 is energized so as to break circuit at 182. The transference of records is thus interrupted and the magnet 184 is de-energized so that the solenoid 109 operates to lift the tone-arm. On reaching the position 107<c>, the tone-arm contact 107 operates to energize the magnet 185 and so breaks the circuit of the solenoid 109 again. The tone-arm then slides down to the playing position, and its contact 108 closes through F the circuit of magnet 160 which starts the turntable motor 61. At the end of the record the tonearm contact 108 again completes through E the circuit of the solenoid 109, and the tone-arm rises to its initial position. During the playing of a record, the record-transferring circuits are broken at A.