| 摘要 |
The driving, braking and freewheeling device for tricycles has a simplified structure including a central circular disc driven by a pedal-operated shaft. Cams, symmetrically positioned around the periphery of the central disc, oppose brake shoes which form a segmented ring within the hub of the vehicle's driven wheel. The inner surfaces of the brake shoes are contoured to act as cam followers. Application of torque to the drive shaft in a first direction forces the brake shoes outwardly until engagement is made with an inner surface of the wheel causing the wheel to rotate. When no torque is applied to the drive shaft there is no cam action to force the brake shoes outwardly against the wheel thus permitting the wheel to rotate freely. When the drive shaft is torqued in the opposite direction, the cams force the brake shoes to engage the inner surface in opposition to the rotation of the driven wheel and effect a braking action.
|
