Patent GB-822463-A (GB)
Title: Improvements in or relating to control mechanism for magnetic sound recording and reproducing apparatus
Inventor: MOORE ERIC ALBERT
IPC: G11B15/10
Filed: 1955-10-19
Abstract: 822,463. Magnetic recording and reproducing apparatus. KOROBUK Ltd., S. Jan. 21, 1957 [Oct. 19, 1955], No. 29877/55. Class 40 (2). [Also in Group XXXVII] Mechanism for controlling magnetic tape or wire sound recording and reproducing apparatus comprises a press-button switch having at least three push-buttons for stopping, normal speed operation and fast winding respectively, the first button being connected to a brake, the second button being used to apply a pressure pad and the third button being adapted to release the brake and the pressure pad. Furthermore, mechanical inter-locking means hold the second button inoperative until released by the first button 1. Two push-buttons 4, 5 may take the place of the second button, button 4 operating a " recording " switch and button 5 a "playback" " switch. Also the functions of the third button may be divided between two buttons, one button 3 for fast forward winding and the other button 2 for fast rewinding. The switch comprises top and end plates 6, 7, 8 respectively and spaced parallel rods 9, 10 on which are mounted contact wafers 11, 11a 11b, 11c and 11d respectively. The movable members of the wafers are actuated by sliders 12, 12a, 12b, 12c, 12d which project through guide plates 13 mounted on the rods 9, 10. Brackets 14, 15 attached to the end plates 7, 8 respectively, support a spindle 16 from which depends a plate 17 in register with the buttons 4, 5. An arm 18 rigid with the spindle 16 is connected to the pressure buttons for the capstan and recording and erasure heads (not shown), a spring 19 being interposed between the arm 18 and the buttons. A second spring 20 acts on the arm 18 to urge plate 17 towards push-buttons 4, 5, depression of either button being adapted to deflect the plate. From a collar 22 rotatable on the spindle 16 extends a finger 21 forming one arm of a bell-crank lever, the second arm 23 being connected by linkage 24, 25 to brake mechanism (not shown) of the supply and takeup spools, a spring or springs being provided to press the finger 21 against the slider of button 1. A detent 27 mounted on an end plate 26 controls the movement of plate 17 by abutment with a block 28 adjustably mounted on arm 18. When the detent is raised, the arm 18 can move freely but when the detent is lowered the arm 18 is obstructed and depression of buttons 4, 5 is prevented. The detent is biased to the locking position by a spring 29 and is raised by a lever 30, which has a bentunder end 30a slidably engaging the finger 21, mounted on a pivot 31, so that while button 1 is depressed and finger 21 lowered the lever 30 holds the detent in the raised position. Any of the other push buttons can then be lowered, the stop button being automatically released by the holding slider of the switch. This release causes finger 21 to rise and spring 29 draws the lever 30 aside and pulls detent 27 downwards to block the arm 18. Thus, after buttons 2, 3 have been depressed, buttons 4, 5 are locked until the detent is reset by depressing button 1.