| 摘要 |
996,219. Change speed gear. B. ELLIOTT (MACHINERY) Ltd. Nov. 6, 1962 [Nov. 8, 1961], No. 39968/61. Heading F2D. [Also in Division B3] A lathe headstock gear-box drives the spindle A and feed drive shaft F so that the ratio of the speed of the spindle A to that of the shaft F is higher for high spindle-speeds than it is for lower spindle-speeds. In Fig. 2, the gears are arranged for low-speed drive of the spindle from the motor M, which drives through belts a shaft D carrying a slidable composite gear DC giving four different drive ratios for a shaft C carrying correspondening gears C1-C4. Gear C4 drives a gear B1 fixed to a shaft B which supports a sliding composite gear B2, B3 engaging selectively with gears A1, A2 fixed to the spindle, giving a total of eight different low-speed drive ratios. A direct drive for the shaft F from the spindle A at a speed of twothirds of the speed of A is by gears A3, F1. The gears B2, B3, F1 are coupled together for endwise movement by a member L operated by a lever X, gear DC being movable by a lever Y. As arranged for high-speed driving, Fig. 3, the composite gear B2, B3 is moved to engage a gear G1 on a shaft G coupled by belts to the spindle. Drive for the shaft F is through a gear B4 on shaft B and an idler gear El engaging gear F1 in its new position. In this arrangement there is a 6:1 reduction between the spindle-speed and that of shaft F. In a modification, Fig. 4 (not shown), there are two intermediate positions of the gears F1 and B3 between their low and high-speed positions. In the first of these, the gears are out of engagement with gears G I,. El, and in the second gear B3 is still disengaged but gear F1 is engaged, resulting in feed without spindlerotation. |
