Patent GB-558552-A (GB)
Title: Improvements in or relating to dictating machines
Filed: 1941-05-12
Abstract: 558,552. Gramophones. STEVENS, A. H. (Soundscriber Corporation.). May 12, 1941. No. 6122. [Class 40 (ii)] [Also in Group XXXIX] In a dictating machine comprising a turntable 11, Fig. 1, a pick-up arm 13 adapted to move freely over the record, and a recording arm 12 carrying a recording head 21 on an horizontal pivot 25 and adapted to be driven across the record, for example as described in U.S.A. Specification 2,133,596 a brake plate 28 is mounted on a vertical rod 29 extending through a slot in the recording arm and controlled by a cam 35, Figs. 2 and 5, so that the brake plate 28 may be brought down on the recording arm to stop the movement of this arm and at the same time to lift the recording head 21 by bearing on a pin 26 extending up through a hole in the recording arm from a tail piece on the recording head. The drive of the recording arm includes a slipping clutch to permit stopping of the arm without stopping its driving mechanism. The machine is intended for recording on thin disc records at 161 grooves per inch as described in U.S.A. Specification 2,200,866. The dictating machine shown comprises a casing 10, Fig. 1, which contains the various parts of the mechanism and circuits and a loud-speaker 53 opening in front. The front is also fitted with a knob 54 for adjusting the sound volume from the loud-speaker, and a knob 42 for positioning the parts to one of three positions indicated by letters R, D, P, Fig. 5, and lamps 46, 47, 48 opposite the pointer 44 of the knob. In the position R, the recording arm 12 can be reset to any desired position; in the position D the recording arm is operative to make a record; and in the position P, the pick-up is operative to reproduce a record. From the right-hand side of the case 10, three pairs of leads 68, 95-98, 99 -119,120 extend to a microphone. The leads 68, 95 connect with the microphone 49. The leads 98, 99 connect with a push-button motor starting switch 97. And the leads 119, 120 connect with a push-button marking switch 118. Leads with a plug 65 serve to connect the machine to an electric supply. Recording arm.-This arm 12, Fig. 2, is driven round during recording by the turntable driving motor 14 through a shaft 15 as described in U.S.A. Specification 2,133,596. This driving mechanism includes a gear-box 18 driving a feed-head 16 through a relatively strong friction brake 17a and the drive is transmitted from feed-head 16 to arm 12 through a relatively weak friction brake 17, which yields when the recording arm is reset by hand. The rod 29 is urged downward by a spring 33 to bear on the periphery of the cam 35, which can be set by the knob 42 on its shaft 36 to any one of three positions. In one position, denoted R by the pointer of the knob 42, the rod 29 bears on a part 41, Fig. 5, of medium radius of cam 35, and plate 28 depresses pin 26 but does not bear on recording arm 12, so that recording-head is lifted from the turntable and the recording-arm can be set by hand to any desired position; in a second position D, the rod 29 bears on the part 40 of maximum radius of the cam 25, and the plate 28 is raised free from both the arm 12 and the pin 26, so that the recording-head is down in operative position for recording; in the third position P, the rod 29 bears on the part 39 of small radius of the cam 35, and the plate 28 depresses the pin 26 and also bears down on the arm 12 to lock this arm, while the reproducer arm is manipulated to operative position and used for reproduction. When the recording-arm reaches the limit of the recording position, a pin 141 depending from the turntable strikes a spring finger 140 on the recording arm once at every revolution of the turntable, producing a clicking noise danger signal. Or a switch is closed to light a signal lamp. Pick-up-arm.-This arm 31 is pivoted on a horizontal pivot 20a on a post 20 rotatable about a vertical axis. The front end of the arm carries the pick-up 52, and the tail end of the arm has an armature 57 adapted to be attracted by a magnet 55 when the pick-up 52 is lifted, so that the pick-up arm is locked with the pickup by this magnetic attraction until the arm is manually depressed to operative position. Record marker.-A device for marking the record disc at the end of a recording operation is attached at 113, Fig. 2, to the recording-head 21. This device comprises a pencil 115 or a punch operated by a solenoid 112 under control of the push-button switch 118, Fig. 1, in the base of the microphone 49. Electric circuits, Fig. 5.-An amplifier 62 and a rectifier 105 are connected through leads 63, 64 and a plug 65 to a supply line L1, L2. The driving motor 14 and in series therewith a brake releasing coil 100 are connected to the leads 63, 64 through the push-button switch 97 in the base of the microphone 49. A solenoid 112 for operating the record marker is connected to the leads 63, 64 through another switch 118 in the base of the microphone. The indicating lamps 46, 47, 48 are connected to the leads 63, 64, through a selector switch 58 on the shaft 36 of the cam 35. The input and output of the amplifier 62 are connected to the recording-arm 12, the pick-up arm 13, the microphone 49, and the loud-speaker 53 through selector switches 59, 60 on the shaft 36 of the cam 35. The rectifier 105 serves to energize the brake releasing coil 107 when a switch 103 is closed by the coil 100 in series with the motor 14 when the motor circuit is switched on. When the cam 35 is adjusted to set the recording-arm for "resetting," "dictating," or "playing," the selector switches are simultaneously set to establish the corresponding circuits. In a modification, instead of three indicating lamps, a single lamp is provided and viewed through a disc on the shaft 36, the disc having three different coloured lenses coming opposite the lamp one at a time in accordance with the setting of the cam 35.