| 摘要 |
721,315. Clutches friction and positive, clutch and change-speed control. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 13, 1952 [June 6, 1951], No. 12089/52. Class 80 (2). [Also in Groups XVI and XIX]. Two speed friction clutches: A two speed clutch for feeding the record strip over a platen for printing thereon by a tabulating machine is shown in section in Fig. 6, the two sides of the clutch H.S. and L.S. are driven from shaft 30 through different gear ratios by gears 29, 34 and 31, 35. A central driving gear 42 is mounted by a bearing on a boss 74 pinned to an axially slidable control rod 37. Alternate friction plates 76, 77 on each side of the driving gear 42 are keyed to the gear 42 and the driven gears 34, 35 respectively. The rod 37 is slidden to engage one or the other side of the clutch by rotation of a member 83 having a tongue 82 engaged in a notch in rod 37. Member 83 is mounted on a shaft 38 Fig. 8 carrying at its other end an arm 39 biased in an anticlockwise direction by a spring 87 and adapted to be displaced in clockwise direction by a solenoid FSS the armature 89 of which is pinned to the arm at 90. Displacement of the arm by solenoid FSS is prevented by a latch 40 which is tripped to allow displacement by a coil FST energized only at a predetermined time in each printing cycle. Previous energization of solenoid FSS ensures a displacement of arm 39 to move the clutch to the high speed drive position immediately the latch 40 is tripped. The solenoids FSS and FST are controlled by signals provided on an endless feed control tape TP, Fig. 2, driven in synchronism with the record strip (see Group XVI) and effect a smooth increase of speed of feeding to high speed and a smooth decrease of speed to slow speed before stopping. Positive pawl clutches: A clutch for feeding the record strip one line space at a time comprises a pair of discs 45, 46, Fig. 9, formed with peripheral teeth 45a, 46a. Disc 45 is freely mounted on shaft 44. Disc 46 is fast with the driving gear 47, Fig. 2 (not shown) and carries a pawl 94, Fig. 9, for engagement with a ratchet wheel 91 which is continuously rotating. The boss 94a of pawl 94 extends through a slot 45b in disc 45 and has an arm 94c engaged in a notch formed in a shallow projecting boss of disc 45. Spring 95 tends to displace the discs relatively so that pawl rotates into engagement with the ratchet to cause rotation of both discs (and of the driving gear). The discs are normally held stationary by a pivoted latch 97, Fig. 2, adapted to abut corresponding pairs of the teeth 45a. 46a to move the discs to an aligned position where pawl 94 is uncoupled. The latch is tripped by a solenoid LS adapted to receive an impulse from a circuit including a thyratron so that the discs can move relatively and allow the pawl 94 to engage the ratchet. The latch 97 is adapted when tripped to close a circuit through contacts 121 to de-energize the solenoid LS immediately and allow the latch to move into engagement with the next pair of teeth 45a, 46a so that the driving gear rotates the' equivalent of one line space. Provision is made for impulsing the solenoid a second or a third time where it is necessary to effect double or triple line spacing (see Group XVI). Alternatively, where it is desired to skip a space on the record strip the solenoid LS may remain energized for the period of the skip. A spring loaded latch 99 acting on the opposite side of the discs prevents rebound when the latch 97 moves into engagement with the teeth.
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