Dictation apparatus

952,634. Dictating machines. DICTAPHONE CORPORATION. Sept. 1, 1960 [Sept. 25, 1959], No. 30159/60. Heading G5R. An improvement of the belt-record/embossing- stylus record/playback apparatus of the type described in Specifications 910,739, 910,740, which are considerably referred to, separate carriages, 34, 36 for the record and playback heads are selectively engageable with a single leadscrew 44 which permits back-spacing of the playback head while allowing the record head to wait at its previous recording position. The leadscrew may be reversed at high speed to backspace the carriage 36, the carriage 34 being held by a sprag 150. Rachets,82, 108, secured to worm-wheels (Fig. 9, not shown) are engaged by solenoid-actuated detents 80, 106 when the carriages are to be driven, and cam means 120 rotated by a half-turn of the centre guide-rod 40 move the heads out of contact with the record during back-spacing. During recording, the carriage 36 normally follows the carriage 34 by the action of a negator spring 114, coupling them; on the resumption of recording, this spring, overcome during the back-spacing operation, returns the carriage 36 to its position close behind the carriage 34. An incremental advance of the carriage 34 when the carriage 36 is backspaced prevents possible double recording due to backlash. In a further embodiment, (Figs. 13, 14, not shown) power-driven means, similar to the earlier machines, return both carriages to their start position and eject the record.