Patent GB-439446-A (GB)
Title: Automatic successive reproducing phonograph
IPC: G11B17/16
Filed: 1934-11-27
Abstract: 439,446. Magazine gramophones. RADIO CORPORATION OF AMERICA, 30, Rockefeller Plaza, New York, U.S.A. Nov. 27, 1934, No. 34086. Convention date, Dec. 1, 1933. [Class 40 (ii)] A phonograph in which a plurality of records are stacked upon a turntable for automatic successive reproduction comprises a pick-up arm for reproducing sound from the topmost record on the stack and an ejector mechanism for removing the topmost record at the end of reproduction thereof, a common operating lever being operatively connected to the pick-up arm by a cable and a cable lever and to the ejector mechanism by a link. The arrangement shown comprises a motor board 1 supporting a motor 2, Fig. 7, which drives a hollow spindle 3 supporting a turntable 5 on which a plurality of records R is stacked and the hub 7 of which is driven by a sleeve 9 itself driven from the spindle 3 by a crosspin 10. A gear 11 on the sleeve 9 continuously drives a gear 12 mounted on a shaft 14 and carrying on its underside a cup-shaped cam member 15, the flange 18 of which is broken away at 19, Fig. 3, for a purpose hereinafter described. Pivoted at 21 to the underside of the motor board is an actuating member 23- shown in detail in Fig. 6-comprising a lever having a lateral extension 24 and terminating in a pair of branches 25, 26. A roller 27 on the extension 24 co-operates as a cam follower with the inner surface of flange 18 whereby the cam 15 is adapted to impart a counter clockwise rotation to the lever 23 against the action of a spring 28 connected at one end to a fixed pin 29 and at the other to a pin 30 upstanding from the branch 26 through an arcuate slot 31 in the motor board. Pivoted at 32 slightly to one side of the main portion of the lever 23 is a lever 33 one end portion of which is connected through a spring 36 to a cable 37 which passes round a guide roller 38 and through an opening 40 in the motor board and is secured to the tone arm 41 carrying the pick-up 42. During reproduction of a record a pin 47 upstanding from the lever 23 occupies a position midway between the side portions 44, 45 of the lever 33 but as soon as the lever 23 begins its initial counter - clockwise rotation under the influence of means hereinafter described, the pin 47 engages the portion 45 and subsequently passes over on to the cam portion 46, the lever 33 being caused to take up the tension on the spring 36 and exert a pull on the arm 41 first to raise it from the played record and then, almost immediately, to swing the arm outwardly to starting position over the next record to be played. On the pin 47 being subsequently returned to its normal position, the arm is permitted to drop down on to the record under control of the spring 36 and exert a pull on the cable 37 which returns the lever 33 to its normal position. To the outer end of the lever 23 is pivoted a link 51 having a slot 52 therein for the reception of a pin 53 depending from a cam plate 54 which is pivoted on a bushing 56 extending through the motor board and receiving the pivot pin 57 of a yoke 58 on which a pin 59 is supported horizontally, Fig. 5. A second yoke 60 which is mounted on the pin 59 for swinging movement in a vertical plane is provided with lateral extensions 61, 62, the latter of which is provided with a pin 63 which extends downwards through an arcuate opening 64 in the motor board into the path of movement of the cam plate 54 whilst the extension 61 carries an adjustable screw 65 co-operating with an ejector arm 66 also mounted on the pin 59 and when engaged by screw 65 during upward travel of yoke 60 is forced upwardly to partake of vertical movement in response thereto. The ejector arm comprises a bottom plate 67 supporting a cover 68 and carrying at its free end a hollow bolt 69 into which is threaded a oentre pin depressing finger 71 having an enlarged head 72 which is spaced from the head of the bolt 69 a distance sufficient to accommodate a friction disc 74 with felt facing 75 and a spacing plate 76 which serves also as a ball race for the ball bearings 77. The spindle 3 is supported on a thrust bearing 78, Fig. 9, and has a spring controlled centre pin 79 the vertical movement of which in both directions is controlled by the pin 10 which passes through a slot 81 therein. The records R are threaded on the pin 79 and the head 72 of finger 71 is adjusted so that, when the disc 74 of the ejector arm is in engagement with the topmost record, the head 72 depresses the pin 79 the thickness of one record only. The topmost record then rotates during reproduction about the head 72, being driven from the records below it by reason of the pressure applied through disc 74. At the completion of playing a record, the lever 23 is caused to rotate in a counter-clockwise direction by means hereafter described so that the link 51 is moved to the left, Fig. 1, and as soon as the tone arm has been removed from the record by the cable 37, the righthand end of the slot 52 in link 51 engages the pin 53 to impart clockwise rotation to the cam plate 54 to engage pin 63 and cause yokes 58, 60 as well as the ejector arm 66 to rotate clockwise and move the topmost record to the left, provision being made whereby the pressure of the disc 74 on the record is gradually reduced. At about the time that the arm 66 has moved the played record to a position where its centre is just past the peripheral edge of the next lowest record, the pin 63 engages the cam edge 83 of a plate 82 overlapping part of the slot 64 so that the yoke 60 and arm 66 are forced upwardly rather rapidly and the combined effects of the cam plates 54, 82 " whips " the played record into a receptacle (not shown). After the cam member 15 has completed half a revolution the lever 23 begins its clockwise return movement under the action of spring 28 pulling the link 51 back and causing the arm 66 to be returned to the centre of the next record and lowered to bring its head 72 into engagement with the pin 79. When the last record is reached the head 72 does not depress the pin 79 so that this record is not removed but is repeated indefinitely thus giving an audible indication that the last record has been reached. If desired, this last record may be recorded with a suitable warning or alternatively such a warning may be recorded on a composition moulded to the turntable 5. Provision is made whereby the disc 74 can always accommodate itself to a new record in spite of the fact that the angle of inclination of the arm 66 increases with respect to each new record. Initiating automatic cycle. A pin 94 extending downwardly from the tone arm engages in the forked arm 92<a> of a lever 92 pivoted at 93 to the motor board. Coupled to the lever 92 by a friction clutch spring 97 is an arm 96 the free end of which passes through an arcuate slot 99 in the motor board and extends into the path of a pin 100 on a cycle initiating pawl 101 pivoted at 102 to the underside of the motor board. This pawl which has a forwardly extending arm 107 terminating in a knife edge 110 is adapted to co-operate with a spring-controlled tripping member 111 pivoted eccentrically at 112 on the upper face of the gear 12 and provided with an upwardly extending trip 116, Fig. 6, terminating in a second knife edge 117. As the tone arm moves across the record with its stylus in the sound groove, the arms 92, 96 are rotated counter-clockwise and a clockwise rotation is imparted to pawl 101. Such rotation is, however, only slight and the knife edge 117 coacts with the face 109 of the pawl 101 to cam it back slightly in a counter clockwise direction so that the predetermined angle between the arms 92, 96 is gradually reduced. When, however, the stylus enters the lead-in groove 119, the tone arm is advanced a greater distance in one revolution of the record and the pawl 101 is advanced to a point at which the knife edge 117 on its next revolution engages the face 108 of the knife edge 110 and gives the pawl 101 a sudden clockwise rotation so that it engages the branch 25 and turns the lever 23 counter-clockwise to cause the follower 27 on its extension 24 to enter the cut away portion 19 of cam 15 and engage the inner surface of the flange 18 whereupon the automatic cycle described above takes place. As the lever 23 advances in a counter clockwise direction, its extension 24 engages the pin 104 on the pawl 101 to restore the latter to its normal position whilst the lever 92 returning to its normal position under the influence of the tone arm carries the arm 96 back with it until the arm 96 is stopped by the pin 30 so as to restore the predetermined angular relation between the arms 92, 96. The gramophone may be adapted for either automatic or manual operation and to this end an index member 121 pivotally mounted at 122 is adapted to co-operate with a dial plate 123 marked with the legends " 10 " " 12" and "MANUAL." An adjustable stop 127 on the index member co-operates with the arm 92<a> to ensure proper location of the tone arm when returned to starting position. The index member also has associated therewith a pivoted switch plate 128 on which are mounted a motor controlling switch 129 and switch operating mechanism for automatically opening switch 129 at the end of playing of a single record manually. This switch operating mechanism comprises a pivoted detent member 130 including a shoulder 131 for operating an L-shaped lever 132 which serves to open the spring contacts 133 of the switch 129 and a pivoted latch member 134, the toe 135 of which is adapted to latch the member 130 by engaging the hooked end 136 thereof to hold shoulder 131 against lever 132 whereby switch contacts are held open. The contacts are opened when the stylus enters the eccentric terminal groove 119<a> of a record of the type described in U.S.A. Specification 1,303,125 by a pawl 137 carried by the arm 92<c> of the lever 92 exerting a camming action on the ratchet plate 140 on member 130