| 摘要 |
PCT No. PCT/EP86/00191 Sec. 371 Date Nov. 21, 1986 Sec. 102(e) Date Nov. 21, 1986 PCT Filed Mar. 27, 1986 PCT Pub. No. WO86/05755 PCT Pub. Date Oct. 9, 1986.The invention concerns a pedal crank as well as a pedal crank drive built up from it for bicycles or the like, in which the effective length of the pedal crank may be altered during the course of the driving stroke by a control stud for alteration of the lever arm. The invention concerns in particular the construction of the pedal crank from a U-shaped basic profile onto which is pushed a covering profile for closing it off and for stiffening and is indissolubly connected to it. The parts of the pedal crank are supported by ball bearings and blocking of the balls during the up and down movement of the pedal cranks is avoided through a special guidance of the balls. The invention also concerns the special construction of the pedal crank drive with a specially constructed eccentric bearing which at the same time absorbs torsional forces by supporting a control stud on the pedal cranks.
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