Patent GB-339073-A (GB)
Title: Improvements in or connected with sound and picture recording or reproducing apparatus
IPC: G03B31/00
Filed: 1929-11-01
Abstract: 339,073. British Consolidated Investments Corporation, Ltd., (Assignees of Rogets, H. W.). Nov. 2, 1928, [Convention date]. Sound recording or reproducing apparatus associated with kinematographs. - Relates to sound and picture recording or reproducing apparatus. A differential gearing, forming a device for keeping the apparatus in step. is operably connected both to a picture camera or projector and to a sound-recording or reproducing machine to operate a switch mechanism which is co-ordinated in a series circuit with a governoractuated switch device connected with the camera or projector thus to control the speed of the motor of the camera or projector. Two picture projectors such as 14, one only being shown in Fig. 1 in plan, each driven by an electric motor 16, are used alternately with two sound-reproducing machines such as 30 which are placed between the projectors. The projector 14 is connected at 18 to a telescopic shaft 19 which is connected bv a universal joint 20 to the clutch 21 and slidable spring-set member 23. The coupling end 25 of this shaft is connected through a change-speed gear 28 with an intermediate shaft portion 29. The two sound-reproducing machines, such as 30, are each provided with an arm 32 to support the synchronizer-carrying casing S<1>. Mounted upon the shaft 29 are two loose sleeves 64, 66, Fig. 3. The sleeve 66 is provided with the fixed clutch member a of the clutch 67, which coacts with a slidable clutch member b when an electromagnet 72 is energized, energization of a second magnet 74 being employed to throw out the clutch. Keyed to the sleeve 66 is a pinion 68<1>, while upon the sleeve 64 is a pinion 65', these pinions engaging with the large gears 80, 81, respectively, provided with the smaller bevel gears 80<1>, 81', which form with the two gears 79 a differential near mechanism. The sleeve 64 is driven through the gear 65 from the swinging and rotatable shaft 85, of which there is one to each reproducing machine, arranged to assume either of the positions shown in Fig. 2. This shaft is provided at its outer end with a gear 87, Fig. 8, operated from the gear 89 keyed to the shaft 90. A disc 91 integral with the shaft 90 rests upon the platform 97 so that the pin 93 will engage in an aperture in the record while the central opening 92 engages the drive shaft 94 geared with the motor 96 of the reproducing machine. The clutch 98 carried by the shaft 90 is operable by a finger plunger 99 to set the platform 97 and record in motion when the motor 96 is started. At the inner end of the shaft 85 is a threaded part 100, mounted loosely upon which is a sleeve 101 provided with an internal threaded portion d and a smooth portion c, Fig 9. Thus, when the shaft 85 is raised to the dotted line position, the sleeve 101 falls to bring the smooth portion c into engagement with the shaft 85, but when in the full line position the threads d engage the threads 100 to cause the sleeve to move from left to right for the lug 103 to engage and close the switch contacts 110, 111, to complete the circuit of the electric pick-up. To regulate the time at which this switch is closed, a support 104 is provided with an adjustable shaft 105 having the teeth 106, Fig. 10, and the rack 107 controlled by the nut 108. Each projector is provided with a shutter shaft 33 which, through a chain 34 and sprocket wheel 39, drives the shaft 38 of the governor-actuated switch mechanism G, Figs. 4 and 5. The depending plate 35 of this device supports the bearings 38<1> of the shaft 38 on which is mounted the spring-loaded governor with weights 42. A disc 45 rotates with the governor and can engage the projection 46 of a contactcarrying pendant 47. The portion 46<1> of the projection 46 is in the path of but spaced from the projection 48 of a switch-operating pendant 49. A bolt 53 supports and regulates the tension of the operating coil springs 52 which normally cause insulating members 47", 49<11> to move so that the contacts 54, 56 and 55, 57 are closed. Thus the opening of these contacts under the action of the disc 45 effects a governing influence on the speed of the motor 16. The relative electrical connections are shown by Figs. 12 and 13. When the reproducing machine 30 and motor 16 are to be started, the switch 113 is closed and a circuit for the motor 16 is completed through the contacts 55 and 57, and 125 and 126, and the motor 16 runs at the desired speed under the action of the governor. A filin-actuated switch will then close contacts 141 and 142 to start the motor 96 of the machine 30, the motor 96<1> being cut out. When the contacts 133 and 134 are closed by the film-actuated switch, the motor 96<1> is started and the motor 96 cut out. Simultaneously with the starting of a projector motor, one of the electromagnets 154 or 157 is energized to connect the contacts 110 and 111 to an amplifying circuit so that, when they are closed, one of the electric pick-ups can effect sound renditon. Under normal conditions, when synchronism between the sound-reproducing machine and the projector is maintained, the differential gearing is stationary and the pendulum 82, under the action of gravity, takes up a position as shown in Fig. 12. Should the motor 96 attain a higher speed, the pendulum 82 will be moved anti-clockwise to close the contacts 119 and 118. This causes the shunting of the contacts 55 and 57, and 54 and 56, to connect the full line current directly to the motor 16 which is speeded up. Should the motor 16 speed too high, the governor disc opens the contacts 54 and 56 and, through the projection 46<1>, the contacts 55 and 57, thus breaking the circuit of the motor 16 until the speed falls,