Patent GB-337979-A (GB)
Title: Improvements in or relating to sound-reproducing machines and apparatus
IPC: G11B17/00
Filed: 1929-11-08
Abstract: 337,979. British Consolidated Investments Corporation, Ltd., (Assignees of Ebeling, C. W.). Nov. 8, 1928, [Convention date]. Multiple machines; automatically making and breaking circuit of electric pick-up by mechanism associated with gramophone.-Relates to an arrangement of two sound - reproducing machines to give continuous soundreproduction, particularly to accompany moving pictures. Each machine has separate driving means adapted to be energized alternately through circuits which are closed to commence the operation of one machine by a switch member which is traversed along a lead screw rotated by the other machine, so that the driving means of the follow-on machine is energized after rotation of the first machine through a determined number of revolutions. Provision is also made for the timely closing of the circuit of the pick-up and amplifying means of the follow-on machine. The reproducing machines 5, 5<1> are provided with turntables 7, 7<1>, motors 8, 8', gearing 9, 9<1> and turntable spindles 10, 10', and there are two selector devices S, S<1>, the motor 8 being controlled by the selector S<1> and the motor 8<1> by the selector S. Upon the standards 16 of each selector is mounted a fixed rod 17 carrying an adjustable slide 18 provided with an indicator 19' adjacent a scale 20 and with a projection 20' carrying a contact 21. Mounted also between the uprights 16 is a feed-screw 23 driven by a flexible shaft 14 to rotate in synchronism with the associated turntable:. Sliding upon the rod 17 is a sleeve 24 provided with a curved interiorly threaded member 26 which may be engaged with the feed-screw 23. Mounted upon the member 26 is a micrometer screw-threaded member 28 having the end 29 in alignment with the contact 21 to engage the latter when the carriage 26 is traversed to the left-hand position. A sliding rod 34 mounted in openings 33 in the supports'16 is provided with a reset lug 35 for co-operation with a lug 27 on the carriage 26 and an adjustable sleeve 36, having a cam end 38, is connected to the rod 34 by means of a screw 37. Coaxial with the feedscrew 23 is a feed-screw 39 engaged by the upper screw-threaded half-nut end 40 of a. member 40<1> which is mounted upon a rod 42 and normally held to the right by a spring 43. When the screw 23 is rotated, the member 4:0<1> is moved to the left against the spring 43. The lower end 44 of the member 40' fits within the bifurcated end 45 of a pivoted lever 46 which is tilted to the left to engage the contacts 48, 49 to energize the soundamplifying circuit from the electric pick-up 6 after a pro-determined number of revolutions of the record 13. In operation, the pick-up 6 is placed with its stylus 6a at the starting point on the record 13. A switch 52 is then closed and the motor 8 energized after the indicator 19<1> has been set with its pointer to indicate the number of revolutions through which the turntable 13 is to be rotated, an exact adjustment being effected by the micrometer screw 28 and dial 30. The feed-screw will then be rotated until the contacts 29, 21 engage to energize the motor 8<1> of the other machine. The operator then slides the last-actuated carriage 26 to the right to cause the lugs 27, 35 to engage and move the cam 38 into engagement with the switch-operating member 40<1> to disengage the contacts 48, 49.