| 摘要 |
A planar drive mechanism comprises a sprocket wheel for a planar chain and a drive shaft for rotating the sprocket wheel. The sprocket wheel has a secondary rim portion for driving the chain and the drive shaft has a primary rim. A clutch mechanism is connected between the primary and secondary rims which comprises a circular groove of trapazoidal cross section formed in the secondary rim which receives a plurality of friction segments connected to the primary rim. Each friction segment is carried by a coupling bolt which is slidably mounted in radially extending bores in the primary rim aligned with the circular groove. The coupling bolts and friction heads while functioning as a unit can be made of two separate materials, the coupling bolt made of material to give it strength and the friction segments made of material to give it wear resistance. |
