Patent GB-590786-A (GB)
Title: Improvements in automatic gramophones
IPC: G11B17/00
Filed: 1944-07-06
Abstract: 590,786. Magazine gramophones. LANDBERG, E. A., and TORPHAMMAR, N. G. Y. July 6, 1944, No. 12953. [A Specification was laid open to inspection under Sect. 91 of the Acts, Jan. 11, 11945.] [Class 40 (ii)] The magazine in a magazine gramophone is movable along a rectilinear track to feed records to the appropriate one of a pair of oppositely facing surfaces, e.g. of turntables 130, 131, Fig. 1, records being fed to each surface without reversal according to the side which is to be played. Magazine. The magazine carriage 5 runs on rails 4 and has partitions 5<1> between which the records are inserted individually. The records rest on a fixed bar 7 which has two slots 9 through which a record can be fed to playing position, the spacing of the slots being such that when the carriage is in position for one record to pass through a slot, passage of a record through the other slot is obstructed. The compartments are of a size to accommodate large diameter records, but some or all of the compartments may be adapted to receive records of smaller diameter by inserting rods 8, Fig. 3, through the appropriate number of partitions. Selecting records to be played. Carriage 5 is driven by a pinion 11, Fig. 12, formed on the end of a vertical driving shaft 12, the pinion engaging a rack 10 on the carriage. Shaft 12 is driven through a reversing coupling which is tripped at each end of the stroke of the carriage. Feeding of the record takes place on the forward movement of the carriage, the record fed being selected by depressing the appropriate key 54 on a keyboard 53, Fig. I. Keys 54 co-operate with cams 56 and contacts 55 on the carriage and are arranged in two banks each of which includes a key for the front or rear side of each record. The cams 56 have gently sloping front faces and steep rear faces and serve to restore anv operated keys 54 to unoperated position when the carriage completes its forward stroke or during the return stroke. Transferring records to playing position. When a key 54 engages a contact 55, coil 58, Fig. 9, is energized and attracts core 59 mounted on one end of a lever 60. The lever is operated against the action of a spring 63 to actuate a toggle device 65, 68. Pin 67 is thus elevated and engages an arm 191 on the control shaft 46 to rock the shaft and operate an arm of a lever 25, Fig. 12, which controls the reversing clutch through which shaft 12 is driven. The clutch is operated to neutral and the shaft 12 and carriage 5 stop. Shaft 46 also carries a bell-crank lever 114, Fig. 7, of which one arm controls a reversing clutch element 113, and this element is moved to clutch engaging position to cause an endless conveyer chain 105 to be driven for lowering the selected record. Chain 105 is mounted on the rear column 3, Fig. 3, of the frame of the machine, and carries a pair of brackets 106 each of which is adapted to receive a record from one of the slots 9, the chain being normally maintained with parts 129 of the brackets filling the slots 9, so that a smooth runway is provided for the records. Chain 105 is locked by engagement of a projection 100 on the chain with toggle 97 which is connected by a link 94 to a detent lever 92. When chain 105 is driven, toggle 97 is forced downwardly and link 94 is operated to move lever 92 which brings its detent 90 into engagement with rack 10 to hold carriage 5 in position. At the same time, brackets 106 move downwardly allowing the selected record to drop through the slot 9, the record being held on the bracket by pairs of catches 124 which rise to a limited extent with respect to the bracket as the bracket falls and clears fixed stops which normally hold the catches out of engagement with the stored records. Movement of chain 105 continues till the record is brought with its centre in register with the spindle of the turntable 130 or 131, Fig. 1, which is arranged so that the record passes close to the bearing surface of the turntable. A clamping head 135 then moves to hold the record on the turntable. Projection 100 on the chain then engages a toggle 120 and a pin 118, Fig. 7, on the chain engages an of bell-crank lever 114. This operates clutch 113 to neutral and locks the chain in position with the brackets clear of the record. Applying the pick-up to the record. Pick-up arms 169 are mounted one in association with each turntable on horizontal shafts 144<1>, 144<11> respectively which are journalled in the rear of the frame and in ports 138 which support the clamping heads 135. The pick-up arms are pivoted about two axes at right angles for movement perpendicular to and across the turntables. The arms 169 are free to move along semi-cylindrical portions of shafts 144 and are normally held with the pick-up away from the turntable by bars 177 mounted on the flats on the shaft 144, the arms being normally held in position with the pick-up clear of the turntables by engagement of spring-urged arms 179<1> which are rigidly connected to arms 179". In the rest position of the arms 169, leaf springs 176 on the ends of the arms are stressed, the brackets 175 carrying these springs engaging the ends of the bars 177 to provide additional retaining means for the arms. As the chain 105 is driven to lower the brackets 106, cam 150 or 151, Fig. 5, thereon engage rollers 148 on'shafts 144 to cause the shafts to rotate. Bars 177 are thus lowered and the pick-ups both move towards the turntables. At the same time shafts 144 operate the clamping heads 135 against the action of springs and arms 179 are operated by brackets 106 to release pick-up arms 169 and, as bars 177 rotate, the appropriate pick-up lands on the periphery of the record to be played and the leaf-spring on the corresponding bracket 176 is released to urge the needle into the sound groove of the record. At this stage a pawl 79, Fig. 9, on the driving shaft 15 operates to disengage toggle 65, 68 from arm 191 and the movement of link 68 thus occasioned operates lever 71 to open contacts to de-energize coil 58. These contacts are closed again by engagement of pins 77, Fig. 3, on the clutch element 13 with lever 71 as soon as shaft 12 commences to rotate. Positioning pick-ups for playing records of large diameter. The shafts 144 are slidable as well as rotatable on their bearings and grooves on the rear ends of the shafts are engaged by pins 156, Fig. 3, mounted on arms 153 carried by vertical shafts which are provided at their upper ends with toggle levers 154 or 162, Fig. 5. The pivot pins 158, 166 of the toggles are situated in the path of a cam 152 which is manually set on the carriage 5 in accordance with the number of records of large diameter to be accommodated. When a large diameter record is selected cam 152 engages one or each of the pins 158, 166 and moves it to its inner position to rock arm 153 and cause shaft 144 to move from the position shown in Fig. 5 in which roller 148 on the shaft engages cam 150 to a position in which the roller engages cam 151 for controlling the movement of the pick-up arm and the clamping-head. Resetting of toggle levers 154, 162 and shafts 144 is effected on the return movement of the carriage 5 by engagement of cam 152<1> on the carriage with the displaced pins 158, 166. Initiating return movement of pick-ups and return of played record to magazine. Each of the pick-up arms 169 is provided with a mercury switch 174 arranged to close the circuit of a coil 181, Fig. 9, when a record has been played. Coil 181 has a core 182 mounted on lever 183 which is operated upon energization of the coil to actuate the toggle combination 185, 187. This rotates control shaft 46 to cause a pawl 49, Fig. 12, on the end of arm 47 to engage projection 52 on the lever 24 which controls, with lever 25, the driving clutch. Lever 25 is disengaged by arm 48. Lever 114, Fig. 7, is also operated to engage clutch element 113 to move into position to engage the driven element to drive chain 105. Brackets 106 are thus elevated, shafts 144 are allowed to turn Under the action of the clamping-head springs, and arms 179 are released. The pick-up rises off the record which has been played and is returned to its initial position and the'record is removed front the turntable and returned to the magazine through slot 9. As chain 105 rises, toggle 97 becomes engaged, operating link 94 to release detent 90 to permit the carriage to move and projection 119 on the chain then engages lever 114 to rock shaft 46 to move clutch 113 to neutral position so that the chain stops and is locked by toggle 97 with brackets 106 in their uppermost position. The rocking of shaft 46 raises arm 47 and pawl 49 which engages lever 24. The latter is raised and the carriage driving clutch engaged so that the carriage completes its forward stroke to release. In reversing the drive, lever 25, Fig. 12, is depressed and insulating blade 83 is inserted between contacts 81 in the circuit of coil 58 to prevent false operation of the coil during the return stroke. Repeating. If it is desired to play a record repeatedly, key 87 on the control board is operated to prepare a circuit tor coil 58 through fixed contacts which are bridged by a projection 196, Fig. 7, on the chain 105 when the brackets have been elevated, whereupon coil 58 is actuated and the record played again. Rejecting record before play. Key 86 on the control panel allows the circuit of coil 58 to be broken so that the carriage 5 will make a forward and return stroke without being stopped to play a record thereby enabling any depressed keys 54 to be restored to their inoperative position. Turntable arrangements. In the arrangement described above, turntables 130, 131 are driven in opposite directions by the bevel gear 134. Figs. 18 and 19 (not shown) show an arrangement in which a turntable 300 having opposed record supporting surfaces is driven by a friction gear 301 and supported by idler wheels 302. In this case the direction of rotation of the turnta