| 摘要 |
1506317 Change speed gear E J MONTALVO 5 Aug 1975 [15 May 1975] 32720/75 Heading F2D A multiple speed transmission, for driving a roller R, winding or unwinding a web W of paper, film or foil, at constant tension, comprises a number (four) of different ratio gear, belt or chain drives transmitting rotation of a constant speed motor to the roller through non- slip clutches 10, 20, 30, 40, engaged successively to compensate for the change in roll diameter during the wind. The gear trains comprise groups of independent countershafts 12 &c., surrounding common input and output gears 3, 4; the latter driving the roller through a friction or eddy-current slip coupling 6. The non-slip clutches 10 &c. may be pneumatic or pneumo-hydraulic, valve-modulated for smooth shift, -and are controlled automatically in accordance with roll diameter by light-sensitive cells 52, 53, 54, mechanical sensors or timers. The belt drive, Fig. 2, not shown, has similar countershafts with a single common input belt and a similar output belt. |
