| 摘要 |
799,081. Electromagnetic brakes. SPERRY RAND CORPORATION. June 13, 1956 [June 13, 1955], No. 18334/56. Class 103 (1). [Also in Group XXIV], A control mechanism for record operating means comprises a rotary armature and a longitudinally movable pressure member for transmitting a drive from a driving gear to a shaft having a drive plate secured thereon, the pressure member being in yieldable non-driving contact with the shaft until a magnet is energized to attract the armature and move the pressure member into driving engagement with the shaft. A driven shaft 57 carrying a capstan 62 for a magnetic tape T is driven from a motor 10 directly through a forward clutch 47, 53 or through a countershaft reverse gear train 27, 23, 24, 32 and a reverse clutch 72, 74, an electromagnetic brake 89, 74 being engaged when either of the two clutches are not energized. The driving shaft 11 carries a gear sleeve 28 to which is secured a spanner member 36 having projections 41 engaging a disc 38, similar projections on a second spanner member 37 also engage the disc to provide an axially flexible coupling, lightly loaded by a spring 33, between the gear sleeve 28 and an armature 42. The armature 42 is secured by tangential taper pins 44 to a sleeve 46, passing through a stationary clutch coil 52, integral with a clutch disc 47 having a friction facing 54. An opposed clutch disc 53 is secured to the shaft 57, the friction facings 54 being held in non-driving engagement by the spring 34 when the coil 52 is not energized to engage the clutch. A second sleeve 66 is similarly axially loaded by a spring 54 through a cup 68 and bearing 67 and is driven by the gear 32 of the reverse train to provide reverse rotation to the shaft 57 through friction surfaces 73 on energization of a magnetic coil 77. The clutch disc 74 pinned to the shaft 57 also co-operates with a brake disc 89 through friction surfaces 91, the disc 89 being integral with a sleeve 88 secured by tangential taper pins 92 to a coupling 102, 101, 99 similar to the coupling 36, 37, 38 secured to the frame 13 of the mechanism. The two clutches and the brake are in non-driving contact when disengaged and are arranged to operate singly. Specification 793,339, [Group XIX], is referred to. |
