Patent GB-460897-A (GB)
Title: Improvements in or relating to sound reproducing machines
IPC: G11B3/08
Filed: 1935-08-02
Abstract: 460,897. Gramophones. ROUTIN, J. L. Aug. 2, 1935, No. 22016. Convention date, June 15, 1935. [A Specification was laid open to inspection under Sect. 91 of the Acts, Feb. 25, 1936.] [Class 40 (ii)] Relates to devices for enabling the playing of a selected portion of a gramophone record to be repeated (as for example a short section of a language-teaching record), and consists in providing mechanism for raising, returning, and lowering the pick-up arm, comprising a longitudinally displaceable rod 10 coaxial with the axis of rotation of the pick-up arm 2, and an adjustable cam device 13 constituting a stop, with which device one or more members 12 on the rod 10 coact to effect the necessary movements of the pick-up arm when the rod 10 is displaced downwards and then upwards. A sleeve 3 through which the rod 10 passes forms a pivot for the arm 2, the latter having pivoted to it at 7 an extended portion 6 which carries the pick-up 8. Mounted on the pivot 7 is a lever 9, one end of which passes beneath the member 6 while the other end has a slot through which passes the end of the rod 10 bearing a knob 11. The member 12 on the rod has two downwardly turned arms 12<1> which pass through slots in the arm 2 and are adapted to engage with the cylindrical member 13. This is rotatably adjustable by means of a worm 19, and, as shown in development in Fig. 2, has two oppositely located notches forming cam walls 14, 15 and stops 16, 17. When, during the playing of a record, the rod 10 is depressed, it first causes the lever 9 to raise the pick-up ; subsequently, the arms 12<1> engage the inclined walls 14, 15, and thus the arm 2 is rotated to carry the pick-up backwards until the arms 121 are stopped by the abutments 16, 17. Afterwards, the rod 10 rises, and allows the pick-up to move gently down on to the record, for repetition of the passage that has just been played. Lowering and raising of the rod 10 may be effected automatically as follows. The rod is normally supported by a lever 20, against which it is pressed by a spring 20<11>, the lever being held up by a detent 28. A disc 24 is driven by the motor M of the machine, and when a pin 27 on the disc pushes aside the detent 28, the lever 20 is released and the rod 10 falls. A cam 25 on the disc 24 afterwards raises the rod by acting on the lever 20. In order to enable repetitions to be effected alternately in a " full tone " and a " muted tone," means may be provided for breaking the sound-reproducing circuit during alternate reproductions of a selected passage. For this purpose, a cam 34, driven at half the speed of the disc 24, is adapted to hold open a switch 36 in the circuit of the sound-reproducing device during the periods when muted reproduction is desired. In this case, only the sound emitted directly by the vibrating needle of the pick-up is heard. A manually operable switch 37 is arranged in parallel with the switch 36. Alternatively, after a muted repetition, a period of complete silence may be obtained by automatically lifting the pick-up off the record. Means may also be provided for giving a reminder when the pick-up needle should be changed. This may be done by providing a needle-box 43 with a spring-controlled lid 44 which is normally held down by a catch 41 on a lever 39. The lever is controlled by a cam disc 38, driven slowly by the motor, so that at the end of a suitable period of operation, (say ten minutes) the catch 41 is moved aside, and the lid 44 flies open. At the same time an audible or visible signal may be given, or the motor may be stopped. The Specification as open to inspection under Sect. 91 describes also a sound record for educational purposes, having separate zones of recording distinguished from each other by differently coloured circles located in the spaces separating the said zones, or by suitably colouring the recorded portions of the disc. The coloured circles may be made on a cardboard or like backing coated with a translucent recording material. For use in conjunction with the record, a printed text appropriate to the record may be provided, having coloured divisions corresponding to the colour markings on the disc. A clockwork indicator, driven in accordance with the speed of reproduction, may move over the text. Another device for lifting and returning the sound-box is also described and shown in Fig. 6 (Cancelled). It comprises an attachment providing a guide 49 for a spring-controlled rod 50 which carries at its lower end a roller 52 adapted to be brought into contact with the record by the operation of a Bowden wire 55. The roller is set at a suitable angle so that when it is depressed so as to raise the sound-box, the latter is returned until it is stopped by an adjustable abutment. This subject-matter does not appear in the Specification as accepted.