| 摘要 |
<p>External chain-shifting gears have a large building width, which necessitates the application of unsymmetrical rear wheels. In order to avoid this a number of toothed rims (1) is embedded with axial displacement on a guiding barrel (4) with side flanges (5). The toothed rims (1) have pins (2), which through slits (3) in the guiding barrel (5) are in mesh with helical grooves (7) in a sleeve (6) embedded inside the guiding barrel (4). A gear changing mechanism rotates the sleeve (6) in relation to the guiding barrel (4), by which means the toothed rims (1) are led from a position of rest at the side flange (5) of the guiding barrel (4) to the middle of the guiding barrel (4). </p> |
