Patent GB-498442-A (GB)
Title: Improvements in magazine gramophones
IPC: G11B17/16
Filed: 1938-02-21
Abstract: 498,442. Magazine gramophones. CLARKE, H. M. G.. and LOWE, A. E. BOWYERFeb. 21, 1938, No. 5469. [Class 40 (ii)] A magazine gramophone having the record rotating in a vertical plane with both playing surfaces exposed is provided with a member for bringing about a record change and a co-operating cam, the cam being axially displaceable so that, when it is out of engagement with the said member, repeated playing of the same record takes place. The turntable, on which a record may be positioned with both its playing surfaces exposed, is rotatable about a horizontal axis and has an axially displaceable spindle which, in the normal position, holds a record on the turntable but, in the displaced position, releases the record. The magazine is downwardly inclined and such as to release a single record on the actuation of a release device by the turntable spindle when the latter is displaced. A turntable, spindle and magazine of this kind are described in Specification. 485,562. The pick-ups and their positioning mechanism are of the type described in Specification 490,551 and comprise two pick-ups carried in spaced relation by counterbalanced levers and associated with a positioning element which, by temporarily destroying the weight balance, causes the pick-ups to sink from an elevated position clear of the record to be played until the positioning element engages the edge of the record whereupon, due to restoration of the balance the pick-ups stop level with the leading grooves of the record. In a gramophone incorporating the above features a record is played once on one or both sides and then a record change is effected. By the present invention means are provided by which in addition repeated playing of a record on one or both sides before changing may be obtained at will. A control lever 81, Fig. 2, pivoted on a support 82 and arranged to be held in any of four positions in a slot 84 moves laterally a double flanged wheel 76 along a shaft 63 by means of a connecting link 78 and a stud 77 which passes through a further lever 79 pivoted on a pin 80. The shaft 63 is rotated intermittently by a motor 67 through a worm drive 64, 65, the worm wheel 64 carrying with it three axially slidable rods 71, 72, 73 to one end of which is fixed the flanged wheel 76 and to the other end of which are fixed two cams, one 75 having one lobe and the other 74 having two lobes. Also fixed to the shaft 63 are a pin wheel 70, contact operating cams 105, 106, and a slotted disc 99 which, in conjunction with a slotted member 100, prevents the control lever 81 from being moved while the shaft 63 is rotating. The upper end of the lever 79 carries a stud 89 operating with a flanged wheel 90 to move laterally a shaft 91 carrying pick up selecting cams 94, 95, see also Fig. 9 (not shown), and a Maltese cross 96 engaging the pin wheel 70. A second Maltese cross 238 on a shaft 237 rotatable in a supporting member 92 carries cranks 232, 231 which, at each revolution, effect the resetting of the pick ups to the beginning of the record as described in Specification 490,551. The pick-ups 200, 201 are pivoted about a vertical spindle 213 and are so operated by the cams 94, 95 that a change from one pick-up to the other is effected at each half revolution of the shaft 91. The arrangement of the pins on the pin-wheel 70 is such that the shaft 237 is given a complete turn at each half revolution of the shaft 63 so resetting the pick ups on each occasion. The pins engaging the cross 96 are such that in three of the selectable positions it is given half a revolution per half revolution of the shaft 63 while in the fourth position, that shown in the drawing, an additional set of short pins is engaged by the cross so giving the latter a complete turn per half revolution of the shaft 63. In order to effect a record change and the repositioning of the pick-ups the shaft 63 is, after one side of a record has been played, turned through half a revolution by a motor 67, whose rotation is then stopped by the interruption of its circuit by a contact 191 actuated by a cam 106 on the shaft 63. When this half revolution takes place with the control lever 81 in the first notch 88 the cross 96 comes into engagement with the additional short pins referred to, so effecting a complete to and fro movement of the pick-ups and causing the repeated playing of the first side of the record, no change of record taking place. In the second position 87, the conditions are the same with the exception that the additional pins are no longer engaged. Thus the shaft 91 only makes half a revolution at a time and the pick ups are positioned on the opposite side of the record each time a side is finished. In the third position 86 of the lever 81, the cam 75 is brought into engagement with a roller 33 carried by a rod 31 which, when moved longitudinally, effects a change of record as described in Specification 485,562. There being only one lobe on this cam 75 a record change only takes place after both sides of a record have been played and thus all the records are played in succession on both sides. In the fourth position 85 of the lever 81, the cam 74 engages the roller 33 and brings about a record change each time the first side of a record has been played, the configuration of the cams 94, 95 being such that in this position the same side of each record is played. Automatic switching arrangements, Fig. 11 (not shown), provide appropriate control of the electrical circuits for the turntable motor 22, control motor 67 and pick-ups.