GB756800A - Improvements in or relating to sound-recording and reproducing apparatus - Google Patents

Abstract

756,800. Sound recording and reproducing apparatus. SVENSKA AKTIEBOLAGET GASACCUMULATOR. June 22, 1954 [June 30, 1953], No. 18283/54. Class 40(2) [Also in Group XXIV] The disc-shaped magnetizable recording medium 1 of a sound recording and reproducing apparatus is driven by direct driving connection with a drive wheel 16, e.g. a rubber roller, which rotates the medium alternatively in opposite directions by being displacable in its own plane so as to be selectively driven through either of two oppositely rotating shafts 15, 18, and the recording head 3 is mechanically coupled to the drive wheel 16 in such manner that they may move together to engage with or disengage from the medium 1. As shown, shafts 15, 18 are driven by a motor 11 through friction gearing comprising the motor shaft 12, a coupling wheel 13, and intermediate wheels 14, 17. The drive wheel 16 is carried by a shaft 19 supported in a bearing 40 about which it is also pivotable and is urged by a spring 41 in a direction for the wheel 16 to engage the medium 1. The shaft 19 is embraced by the forked upper end of a lever 20 pivoted upon a shaft 23 to turn either clockwise or anticlockwise when acted upon by respective electromagnets designated by arrows 21, 22 whereby the wheel 16 engages the shafts 15, 18 to provide the forward or reverse drive. A spring 25 and flats on the shaft 23 and in an aperture 24 determine the neutral position of lever 20. The recording head 3, mounted on a lever 26 pivoted on a shaft 27, is biased towards the medium 1 by a spring 28 but may be disengaged therefrom, together with wheel 16, by an electromagnet designated by an arrow 43 acting upon an arm 29 of lever 26, which arm forms the coupling with the drive wheel by its engagement with shaft 19. The supply of current to electromagnet 43 may be controlled by a control button actuated switch not shown or by downwards movement of a member 2 about which the medium 1 is rotatable, such movement being conveyed to contacts 30 in parallel with this switch through a frame 4 having guides 56, wheels 8, 9 on a shaft 7 and a holder 31, a spring not shown providing the return movement. The head and medium are relatively displaceable along a radius of the latter, and as shown, a roller 10 having a rim engaging a spiral track on the upper side of medium 1 moves the latter radially during operation, such movement being allowed by members 4...9. A higher or lower than normal speed drive of the medium may be effected by engagement of cam surfaces 35, 36 with the coupling wheel shaft 33 which under control by a spring 32a, moves axially to engage the wheel 13 with larger and smaller diameters of the motor shaft 12. Return to the normal speed when starting recording is provided for by a lever 38 on the recording switch push button 37, which when depressed, causes the cams 24 to disengage from the shaft 33 which is then returned by a spring 32.