Patent GB-485494-A (GB)
Title: Automatic record-changing gramophone
IPC: G11B17/02
Filed: 1937-02-03
Abstract: 485,494. Magazine gramophones. SMALL, T. W. Feb. 3, 1937, No. 3217. Convention date, March 13, 1936. [Class 40 (ii)] Relates to magazine gramophones having a tiltable magazine of the kind described in Specification 422,586, and consists mainly in arranging the magazine to be set to two different levels in succession and for the stroke feeding a record to the turntable to be automatically adjusted according to the size of the record, so that records of any size in the magazine may be played, each record on both sides successively, and the several records one after another. The gramophone is driven by an electric motor 36, Fig. 2, which is geared to the turntable spindle 37 and also to a stub-shaft 39 carrying a sprocket 40 connected by a chain 41 to a sprocket 42 free on a cam-shaft 43. This is in turn connected by pinions 46, 47 to a second cam-shaft 48, which makes one revolution for each two revolutions of the cam-shaft 43. A clutch member 44 splined on the cam-shaft 43 is urged towards the other clutch member on the sprocket 42 by a spring 45, but is normally held off by a pin 53, interlocked with a hook-shaped lever 55. The pin 53 is on the armature 51 of a solenoid 49, and the record changing mechanism is set in operation by the energization of the solenoid when the playing of a record is completed. The finger 53 releases the clutch and allows it to connect the sprocket 42 to the shaft 43. The finger 53 is then deflected against a stop 60 by a spring 59 and its return is blocked by the hook 55. During the rotation of shaft 43, a cam 61 thereon rocks the hook 55 to allow the finger 53 to slip into the groove 54 of the clutch member 44 ; and when the shaft has completed one revolution, the cam 61 releases the hook 55, which under the influence of a spring opens the clutch. Various cams on the shaft 43 control the lifting and returning of the pick-up arm, and the changing of the record ; and the shaft 48 serves to place the magazine at two different levels in succession so that one record may be played on both sides before the next record is played as explained below. The pick-up arm 63, Fig. 18, is mounted on a horizontal pivot 66 on a bushing 67 rotatable about a vertical axis. When the shaft 43 is set in rotation, a cam 74, Fig. 7, thereon rocks a lever 71, which lifts a pin 69 and raises the pick-up arm 63 off the record. Then a flange 162, Fig. 2, on a horizontal slide 91, which is reciprocated by the cam-shaft 43 as explained below, strikes an arm 160 on the bushing 67 and rocks the pick-up arm outward to a position beyond the starting point of either a large or a small record, this taking place while the record is being returned to the magazine. At the end of the return stroke of the slide 91, which brings a record from the magazine to the turntable, a spring plunger 163 on the slide strikes a pin 161 on the arm 160 and moves the pick-up arm inward over the starting groove of the record. The return stroke is limited according to the size of the record as explained below, and a dent 165 or 166 in a base plate 68 on the pick-up is brought over the pin 69 to locate the pick-up arm according to whether the record is large or small. The record changing operation is brought about by the reciprocation of the horizontal slide 91 in conjunction with a record lifting device. At the beginning of the rotation of the camshaft 43, cams 84, Figs. 2 and 8, thereon rock levers 82, which lift pillars 79 carrying a pair of elevators 75, one on each side of the turntable. These elevators are stepped as shown to fit and guide the record, whether large or small, and lift it up to the level of fixed guides 99, Fig. 1, forming a prolongation of the elevators. The record is then returned to the magazine by an arm 86. This arm is mounted on a pivot 88 carrying a crank 90 with a pin 93 fitting a slot 94 in the slide 91. The slide 91 has a depending yoke 95, Fig. 6, co-operating with cams 98, 147 on the shaft 43. Fig. 6 shows the position of the parts when a record is being played. When the shaft 43 rotates after the playing of the record, the cam 98 bears on the right flange 96 of the yoke 95 and drives the slide 91 to the right until a shoulder 107 on the cam slips past the flange 96. Near the end of this stroke of the slide 91, a projection 103 thereon strikes a spring buffer 104, which returns the slide slightly to the left when the shoulder 107 slips off the flange 96. This stroke of the slide causes the arm 86 to swing to transfer the record from the turntable to the magazine and to swing back slightly to withdraw itself from the magazine. Towards the end of the rotation of the shaft 43, the cam 98 strikes the left flange 97 of the yoke 95 and returns the slide 91 to the left. The arm 86 swings back to its original position ; and a similar arm 87 is also swung to the left, and this arm withdraws a record from the magazine and brings it over the turntable. If the record is of large diameter it bears on roller 148, as shown in Fig. 9, and rocks levers 149, 154, which withdraw cam 147 from yoke 95 ; the end of the left stroke of the slide 91 is then determined by the cam 98, and causes the arm 87 to centre the large record over the turntable and the pick-up arm to be brought over its starting groove. If the record is a small one, it passes clear of the roller 148, which under the influence of a spring 153 holds the cam 147 in position to engage the flange 97 of the yoke 95. The left stroke of the slide 91 is then extended to ensure the centring of the small record over the turntable by the arm 87 and the positioning of the pick-up arm over its starting groove. The magazine shown in perspective in Fig. 12 is an open structure comprising two side walls 108, an end wall 108<1>, a transverse plate 109, and two pairs of laterally disposed plates 111, 112 dividing the magazine into two compartments, a main one 137 and a shallow upper one 136. This magazine is provided with trunnions 113 forming the pivotal connection between arms 120, Fig. 6, and links 121, which support the magazine. The arms 120 are pivoted on fixed top brackets 122, and the links 121 are connected by pivots 131 to levers 123 pivoted on fixed bottom brackets 124. A T-shaped piece 132 carrying a roller 133 is attached to a trunnion 113 and co-operates with a cam 130 mounted on one of the pivots 131 and connected by a link 129 to a crank 128 on the cam shaft 43. While a record is being played, the magazine is in the vertical position shown in Fig. 6. After the record has been played and as soon as the shaft 43 begins to rotate, the link and cam mechanism 129, 130 turn the magazine clockwise to the inverted horizontal position in readiness to receive the record from the turntable transferred by the arm 86, as explained above. During the middle part of the rotation of the shaft 43 while the slide 91 is stationary at the end of its stroke to the right, the link and cam mechanism 129, 130 turn the magazine counterclockwise through the vertical position to the upright horizontal position. Then, when the slide 91 makes its return stroke to the left, a record is transferred from the top of the magazine to the turntable ; and finally the magazine is tilted back to the vertical position where it remains while the record on the turntable is being played. The cam-shaft 48 makes one revolution for every two revolutions of the cam-shaft 43 as explained above, and cams 125 on the shaft 48 rock the levers 123 and lift the magazine trunnions 113 to a higher level. When the magazine is inverted and at the higher level, the record from the turntable is inserted into the shallow chamber 136 of the magazine, and, this chamber coming to the top when the magazine is turned to the upright position, the same record is again fed to the turntable but in an inverted position so that both sides of the record are played in succession. When the magazine is next inverted, it is presented at the lower level to the record from the turntable, and this record enters the bottom of the magazine now at the top, and when the magazine is next turned to the upright position a fresh record is presented for transfer to the turntable. Thus, both sides of a record are played in succession, and the records are played one after another starting from the bottom. The arm 87 is carried by a horizontal pivot, which allows the arm to accommodate itself to the level of the magazine.