Patent GB-442112-A (GB)
Title: Improvements in sound recording or reproducing apparatus
Filed: 1935-04-16
Abstract: 442,112. Optical sound recording or reproducing apparatus. CRUDO, F., 245, Defensa, Buenos Aires. April 16, 1935, No. 11773. Convention date, June 22, 1934. [Class 40 (ii)] [See also Group XX] An electro-optical sound recording or reproducing apparatus of the type having a rotary cylindrical record carrier is provided with means for automatically positioning and securing the negative or record around the cylinder upon energization of the motor for driving the cylinder. The sound reproducing device shown in Figs. 1, 2 and 4, comprises a cylinder 1 having a row of pins 3 over which perforations along one end of the record 2 are adapted to be engaged, the cylinder being driven by a motor 4 arranged in the interior thereof. A record holding rod 8 is carried on the cylinder by pivoted arms 9, the rod being held against the cylinder by a spring. Frame members 11, 12 are provided at the ends of the cylinder, a rubber setting brush or roller 13 being carried by these members by means of arms 14 and an axle 15, the latter being formed with an integral arm 16 foi controlling the brush. Pivoted at 18 on the member 11 is a spring-controlled cam-shaped member 17 pro.- vided with a stop 20 which engages in the bifurcated end of the arm 16, the member 17 being connected to a control key 23 by means of a pivoted link 21 and rod 22. The members 11, 12 also support the ends of screws 24, 25 which are driven synchronously with the cylinder 1 through gears 26, 27, 28 and chain 29. A casing 31 containing the exciting lamp 30, lens system 32 and photoelectric cells 33 is mounted on a carriage 34 which slides on guides 35, 36 and has pivoted thereto a member 38 adapted to be rocked alternately into engagement with the advance screw 24 and backward motion screw 25 by a rod 40 carried by arms 41, 42, the arm 42 being pivoted on an axle 43 whilst the arm 41 is connected to a rod 44 carrying a knob 45 and connected by a pivoted link 46 with the rod 22. A spring-controlled cam lever 47 pivoted at 48 carries near one end a stop 49 which, in its lowered position, lies in the path of a stop 51 carried by the cylinder 1 and near its other end a contact arm 52 adapted when lowered to close contacts 53, 54 in the motor circuit, this end of the lever being held in its lowered position by a hook member 55 which can be moved to release the lever by a pivoted arm 56 carried by the carriage 34. A plate spring 57, Figs. 1 and 4, is mounted on an insulating base 58 and carries a hook member 59 which engages and holds the arm 42 controlled by spring 61 in its raised position so as to close the circuit of the exciting lamp 30, the hook 59 being adapted to be released from engagement with the arm 42 by a stop 60 on one of the photo-electric cells 33. A mirror 62 carried by the casing 31 is adapted to reflect a pencil of light through a window 63 in an opaque screen 64 on to the record 2 in order to ensure that the reproducing light beam is correctly aligned on the record. The operation of the device is as follows. The perforations in one end of the record are placed over the pins 3 and the rod 8 is applied over this end of the record. The control key 23 is then depressed rocking the cam 17, the lower end of which rocks the lever 47 so that the stop 49 is raised out of the path of the stop 51 on the cylinder 1 whilst the contact arm 52 closes the motor circuit, the lever 47 being held by the hook 55. The stop 20 on the cam 17 at the same time depresses the setting brush 13 which applies the record against the cylinder. The upper end of the cam 17 is now projecting above the surface of the cylinder so that towards the completion of the application of the record to the cylinder the rod 8 is momentarily raised by this end of the cam and then falls to secure the free end of the record. Depression of the control key 23 also rocks the member 38 into engagement with the advance screw 24, the arm 42 on the rod 40 being engaged and held by the hook 59 to close the circuit of lamp 30. The carriage 34 is then traversed across the record until the stop 60 coacts with the hook 59 to release the arm 42 so as to extinguish the lamp 30 and rock the member 38 into engagement with the backward motion screw 25 which returns the carriage 34 to its initial position when the arm 56 coacts with the hook 55 and releases the lever 47 so as to open the motor circuit and interpose the stop 49 in the path of the stop 51. According to a modification, Figs. 7 and 8 (not shown), the return motion of the carriage 34 is effected by a cord, a modified arrangement for braking the cylinder and opening the motor circuit on the return of the carriage to its initial position being also described. The advance of the carriage can also be effected by means of a rack and its return by a rack or a spring. Instead of stopping the carriage when it reaches its initial position, the reproduction of the record may be repeated automatically as many times as desired.