Rear derailleur for a bicycle
AssigneeShimano Industrial Company Limited
InventorsMasashi Nagano, Mitsuhide Isobe
Life of this patent
Estimating the term…
Abstract
A rear derailleur for a bicycle, which is provided with a holder connected between a fitting member fixed to the bicycle frame and a pantograph mechanism supported to the fitting member through a transverse stud. The holder offsets the position of a movable member with respect to the fitting member, or in other words, the position of the movable member with respect to each sprocket at the freewheel, so that when the movable member is moved axially of the freewheel to switch a driving chain to a selected sprocket, the movable member is moved radially of the freewheel. Therefore the movable member, when moved axially of the freewheel for switching a driving chain to a selected one of the sprockets, is moved radially of the freewheel.
Claims11
A rear derailleur for a bicycle, which is adapted to switch a driving chain to a sprocket of a multi-stage freewheel attached to a rear hub of the bicycle, said derailleur comprising;
- (a) a fitting member fixed to the bicycle frame;
- (b) a pantograph mechanism swingably supported to said fitting member through a first transverse shaft;
- said pantograph mechanism comprising a supporting member pivoted to said fitting member through said first transverse shaft, two linkage members pivoted to said supporting member through first and second longitudinal shafts, and a movable member pivoted to said linkage members through third and fourth longitudinal shafts, said supporting member, two linkage members and movable member, being formed in a parallelogram, whereby said parallelogram is transformed to allow said movable member to move axially of said freewheel;
- (c) guide cages having two pulleys and being supported swingably to said movable member at said pantograph mechanism through a second transverse shaft;
- (d) urging means for urging said guide cages in the direction of applying tension to said driving chain guided by said pulley;
- (e) a holder provided between the fitting member and said pantograph mechanism,
- said holder holding said pantograph mechanism in a particular position with respect to said fitting member to thereby offset the position of said movable member with respect to each of the sprockets at said freewheel, so that when said movable member is moved axially of said freewheel to switch said driving chain to one of said sprockets said movable member is moved radially of said freewheel.
Dependencies are inferred from the claim text.