| 摘要 |
PCT No. PCT/SE86/00558 Sec. 371 Date Jun. 14, 1988 Sec. 102(e) Date Jun. 14, 1988 PCT Filed Dec. 9, 1986 PCT Pub. No. WO87/03662 PCT Pub. Date Jun. 18, 1987.In a multiple-step gear drive there are two stationary toothed wheels, comprising a driving wheel and a driven wheel. Their spacing and positions remain constant as the housing that supports gear trains is rotated. For each gear step or position there is a gear train. Each train comprising one or several gear-wheels and in engagement with each other, all these gear-wheels being rotatably jounalled in a housing. The housing is movable substantially parallel to a plane running perpendicular to the shafts of the stationary toothed wheels, to be brought into a specific engagement position for each gear step in which the gear train is in engagement with both stationary toothed wheels. The housing and gear wheels are thus arranged so that in at least one gear step the housing can be disengaged from its engaged position in two substantially opposite directions, thus moving the corresponding gear train in the selected direction and thereby breaking the driving connection between the two stationary toothed wheels. |
