Abstract: A variable speed mechanism includes at least two clutches provided on a driving shaft to allow for selectively driving, by using different ones of the clutches, transmission wheels having different gear ratios. Each of the clutches includes a clutching assembly and a ball arresting assembly that operates the clutching assembly. The ball arresting assembly includes a driving disc and a driven disc opposite to each other. The driving and driven discs have surface adjacent to each other and respectively formed with two curved guide grooves extending from a deep point to a shallow point. The curved guide grooves are provided with a guide bead arranged therein so that when the driving disc rotates with respect to the driven disc, the driven disc generates a movement of leaving or approaching the driving disc so as to achieve an engagement or disengagement operation of the clutching assembly.

Abstract: A reliable mechanical clutch is disclosed. The clutch includes a clutch assembly and an engagement assembly together selectively coupling or decoupling driving and driven members. The gist of the present invention lies in grooves of end-to-end gradually reduced depth are formed on interfacing faces between active and passive rings where balls are accommodated to roll. The active and passive rings, when turned, would be close to or away from each other, thereby causing the clutch assembly to function. The clutch is therefore structurally simple, has a low failure rate, and may effectively reduce its form factor and production cost. Its function is purely through mechanical operation with limited triggering force but produce a powerful push, thereby achieving greater reliability.

Abstract: A clutch with high binding ability comprises a plurality of detent components provided between a left and a right lateral plates and each detent component can be pulled back to its original location by a resilient element. The detent block of each detent component is movably positioned between the left and the right lateral plates. The detent element of each detent component is slidably connected onto the detent block. One end of the detent element is provided with a groove for locating a positioning bar therein. Thereby, when the clutch rotates, the radial force of the detent element can be increased in order to enhance the detent ability of the detent element. When the rotational speed of the clutch is decreased to be the rotational speed of passive driving or to be lower than the rotational speed for engagement, the detent element can be pulled back to its original location by means of the elastic element located between the detent block and the detent element.

Abstract: A clutch with high binding ability comprises a plurality of detent components provided between a left and a right lateral plates and each detent component can be pulled back to its original location by a resilient element. The detent block of each detent component is movably positioned between the left and the right lateral plates. The detent element of each detent component is slidably connected onto the detent block. One end of the detent element is provided with a groove for locating a positioning bar therein. Thereby, when the clutch rotates, the radial force of the detent element can be increased in order to enhance the detent ability of the detent element. When the rotational speed of the clutch is decreased to be the rotational speed of passive driving or to be lower than the rotational speed for engagement, the detent element can be pulled back to its original location by means of the elastic element located between the detent block and the detent element.