Improvements in and relating to magnetic sound recording and reproducing apparatus

662,462. Magnetic recording and reproducing apparatus. BRITISH ACOUSTIC FILMS. Ltd. March 1, 1949. No. 5507/49. Class 40 (ii), The drum 7 of a magnetic recording and reproducing apparatus having heads 6, 8 pressing on a film 1 is made of non-magnetic, preferably insulating, material (e.g. artificial resin) and has stationary screening shields 21, 22 of magnetically soft material extending into its interior. The strip,' consisting of a film 1 coated with magnetic material 2, is drawn by a power-driven sprocket 4 over drum 7 which is mounted on the same shaft as a flywheel 13 in order to maintain velocity stability. The recording head 6 and reproducing head 8 mounted within screening cans 14, 15 are pressed onto the strip by leaf springs 16, 17.