Patent GB-764490-A (GB)
Title: Improvements in automatic or magazine gramophone apparatus
Inventor: COLLARO CHRISTOPHER
IPC: G11B17/16
Filed: 1954-04-06
Abstract: 764,490. Automatic gramophones. COLLARO, Ltd. April 5, 1955 [April 6, 1954], No. 10092/54. Class 40 (2). In a centre post type record changer playing mixed diameter records, in which a trigger arm projects into the path of a falling record and controls the setting down position of the pick-up, means are provided whereby after the initial displacement of the trigger arm by a falling record the trigger arm is caused to be swung away from the edge of said record. The setting of the pick-up arm at the appropriate initial position is effected by means of a vertically slidable stop member 39 having surfaces 50, 51, 52 which engage surfaces 54, 55, 56, respectively, according to the diameter of the record last falling to the turntable, the surfaces 54, 55, 56 being part of a plate 53 moving about a shaft 68 under the control of a friction drive. The stop member 39 is lifted and lowered by a bell-crank 33, which is initially held in the uppermost position, Fig. 6, against the tension of spring 40 by a tongue 43 on a member 27 pivoted at 28 and engaging a notch 44 in the bell-crank 33. The trigger arm 24 is pivotally mounted on the member 27 at 26 and held by a spring 30 against a pin 32 on member 27 so that the trigger arm 24 normally forms a rigid lever against downward movement. The member 27 is provided with notches 45, 46, Fig. 8. When a record of the smallest of three sizes falls to the turntable it does not come in contact with trigger arm 24 and the mechanism remains as shown in Fig. 6, and the surface 56 on plate 53 comes into contact with surface 52 on stop member 39 as the pick-up arm is traversed inwardly, and this position corresponds to the starting position for the smallest sized record. When a record of intermediate size 58, Fig. 9, falls to the turntable, the trigger arm 24 is tripped and the bell-crank 33 is released and, under the influence of spring 40, takes up a position in which a pin 48 on the bell-crank 33 engages notch 45 in member 27, and in so doing moves trigger arm 24 out of contact with the record 58. The position in which bell-crank 33 comes to rest sets the position of stop member 39 such that its surface 51 is placed in the path of surface 55 on plate 53, whereby the inward traverse of the pick-up is arrested at a position corresponding to the setting down position for intermediate sized records. When a record of the largest size 57, Fig. 10, falls to the turntable, the trigger arm 24 is moved by the falling record to a position in which pin 48 engages the lower notch 46 in member 27, and in so doing moves the trigger arm 24 clear of the record 57. The resulting position of stop member 39 places surface 50 in the path of surface 54 on plate 53, corresponding to the starting position for the largest sized record. The pick-up movements are controlled in a well-known manner by cams operated by a single rotation of a gear 23, Fig. 2. The raising of the pick-up arm 12 is effected by means of a bell-crank 72, Figs. 3 and 7, acting on the shaft 68, through the medium of a link 75, arm 62 and a bar 60 connected to the gear 23. The plate 53 carrying the surfaces 54, 55, 56 forms the lower end of a member 80 comprising part of the pick-up arm support 66, and has a friction surface 82 which is engaged when the shaft 68 is raised and the pick-up lifted from the record. The stop member 39 is automatically raised to the initial position at the end of each automatic cycle by means of a stiff wire spring 90, Figs. 4 and 6, which acts as a bell-crank. One end enters a hole in the lower part of member 39, while the other end is engaged by an elongated hole in an arm 93 pivoted at a fixed point 94, and moved clockwise by a cam surface 97 on arm 62 under the control of bar 60. The motor 22 is stopped when the last record has been played and the pick-up arm swung to its outermost position. When the last record falls to the turntable a shaft 100 carrying a steadying arm 21 drops and presses down an arm 102 which lowers a slotted plate 106 so that an arm 83, moved under the control of gear 23, becomes latched back, in the position shown, at an appropriate part of the next automatic cycle. The lever 83 engages a sliding plate 111 in a direction to rock a bar 112 about pivot 113 to place the downturned end 114 in the path of a pin 115 on bar 60, so that during the movement of the latter the switch 120 is tripped.