Patent GB-1162857-A (GB)
Title: Improved Means for Pick-up Arm Location in an Automatic Record Player
Inventor: LANE NORMAN
IPC: G11B17/16
Filed: 1967-02-07
Abstract: 1,162,857. Automatic record players. BSR Ltd. 6 May, 1968 [7 Feb., 1967], No. 5678/67. Heading G5R. The invention relates to an automatic recordplayer for playing records of different sizes, of the type in which records are fed singly in succession from the bottom of a stack carried on a (stationary) spindle extending upwardly from the centre of the turntable; the pick-up arm is horizontally pivoted on a spindle pivotally mounted for movement about a vertical axis; and the mechanism for performing the conventional record-changing cycle of operations includes an oscillating member which makes one to-and-fro movement of constant amplitude from beginning to end of each cycle and a quadrant selector plate which is fixed to the lower end of the pick-up arm spindle and has a number of abutment edges to be engaged by an automatically- or manuallyadjustable selector bar according to the size of record to be played. Fig. 2 is an underneath view of the apparatus with the oscillating member 27 in one extreme (the " start ") position, Fig. 5, being an erect cross-section looking left, and Figs. 4 and 6 are respectively similar views with the oscillating member 27 in the other extreme (the " mid-cycle ") position. According to the invention the quadrant selector plate 33 is provided with a projection 43 extending therefrom towards the oscillating member 27, and the oscillating member 27 has mounted thereon a driving member 44 which can pivot in bearing grooves 47 in the oscillating member about an axis in, or parallel to, the plane of movement of the oscillating member, the driving member 44 having two arms 50a, 50b, projecting therefrom in the general direction of the quadrant selector plate 33 and spaced apart in a direction normal to the pivotal axis of the driving member. In operation, the oscillating member 27 is in the position of Fig. 2 during playing of a record. When the record has been played, conventional tap-tap mechanism initiates rotation of a gear which incorporates a cam track (not shown) in which a roller 26, rotatably mounted in the-oscillating member 27, engages. As the oscillating member is moved by the cam gear (about its pivot 28), arm 50a of driving member 44 makes contact with the projection 43 on selector plate 33. According to the invention, the frictional resistance provided by the bearings 47 (and governed, as shown, by a retaining leaf spring 48 anchored at 49), prevents rotation at this stage, of driving member 44. The quadrant selector plate is thus forced into rotation, and, with it, the pick-up arm spindle 19 to which it is secured, and the pick-up arm (not shown). When the selector plate 33 comes to rest in the Fig. 4 position, by engaging a stop (not shown), the oscillating member 27 has not stopped moving. According to the invention the frictional resistance of the bearings 47 is overcome by continued contact of the now-stationary projection 43 with the still-moving driving member 44. In consequence the driving member 44 is rotated until finally it is orientated as shown in Figs. 6 and 4. The oscillating member 27 is now also in the position shown in Figs. 6 and 4. As the oscillating member 27 is being returned to the Fig. 2 position by continuing rotation of the cam gear, the quadrant selector plate 33 is again contacted, and driven, this time by arm 50b of the driving member 44, until plate 33 is again stopped by engagement of one of the abutment edges 35 with a lug 39a on a pivoted selector bar 36. The oscillating member 27 continues moving, with consequent swing-back of driving member 44, until both these members are in the position of Figs. 2 and 5 again. At this final stage the pick-up arm has been lowered by downward movement of a pin 30, (vertically slidable in the deck plate 10) into a depression 32 on the oscillating member 27, so that the stylus engages the record start groove; also the selector bar 36 has been moved out of the way of the plate 33. The pick-up arm and quadrant selector plate 33 are now free of all constraint so that they may be pivoted inwards by playing of the record. A slot 34 in the plate 33 permits the plate to move in relation to the pin 30. Fig. 2 shows plate 33 at a position near the end of playing of a record. The selector bar 36 is positioned, when appropriate, by mechanism including a recordsize-selector knob 41 on a member 40, and is moved, when appropriate, by mechanism associated with the oscillating member 27.