Resistance device for an exerciser

DETAILED DESCRIPTION The main object of the present invention is to provide a resistance device which is adapted to be mounted on an exerciser, such as a bicycle, and which can impart resistance to the exerciser.
Accordingly, the resistance device of the present invention is to be used with an exerciser, such as a bicycle, which has an axle, a wheel mounted on the axle, and a driving unit which is manually operable to drive rotatably the wheel on the axle.
The resistance device includes a support frame and a resistance unit.
The support frame is adapted to be mounted on the exerciser so as to raise the wheel above a ground surface to prevent the ground surface from providing resistance to rotation of the wheel.
The resistance unit includes a transmission shaft, weighting means, a contact roller, and parallel first and second support members.
The transmission shaft is mounted rotatably on the support frame and is adapted to be driven rotatably by the wheel.
The transmission shaft has opposite first and second end portions.
The weighting means is applied on the transmission shaft so as to generate a resistance to rotation of the transmission shaft in order to resist, in turn, the rotation of the wheel.
The weighting means includes first and second balancing weights sleeved respectively on the first and second end portions of the transmission shaft for co-rotation therewith.
The contact roller is sleeved on the transmission shaft and is adapted to be placed in contact with the wheel such that rotation of the wheel by the driving unit results in co-rotation of the contact roller and the transmission shaft therewith.
The first and second support members are mounted on the support frame.
Each of the support members has a mounting hole provided with a bearing unit for supporting rotatably a respective one of the first and second end portions of the transmission shaft thereon.
The contact roller is disposed between the support members.