| 摘要 |
994,140. Variable-ratio gearing. CINCENNATI MILLING MACHINE CO. March 17, 1964 [June 12, 1963], No. 11310/64. Heading F2D. [Also in Division B3] A drilling machine quill feed transmission comprises an input shaft 12 having an eccentric portion 37, an output shaft 14 carrying two over-running clutches 44, 46, and a pair of integral racks 60, 62 located on eccentric 37, and co-operating with gears 64, 66 on the clutches to thereby rotate shaft 14 in the clockwise direction. Shaft 12 is rotated by a gear 16, and is movable axially in housing 10 relative to the racks, so that the stroke of the latter can be varied. A bush 50 is keyed to shaft 14 at 52, and each clutch 44, 46 comprises a ring 48 and a pair of rollers 54 and springs 56, which are received in notches 58 formed in the bush. Shaft 14 is rotated clockwise by rack 62 when the rack moves to the right, Fig. 1, and it is rotated clockwise by rack 60 when the latter moves to the left. The racks are held axially relative to shaft 14 by a tongue 86 carried in a block 90, and shaft 12 is axially adjusted in the housing 10 by a dial 68 fixed on a shaft 70, a flange 74 on the shaft carrying a shifter 76 which co-operates with a bearing 78 fixed on the shaft 12. |
