| 摘要 |
A hand brake including a lock-up and release clutch mechanism, a ratchet rotatable by a hand wheel connected thereto through a drive shaft, a nut screw-threadedly arranged on the shaft and effective, upon rotation of the wheel and shaft in one direction, for advancing on the nut on the shaft to cause the ratchet to be clamped between respective friction surfaces of the nut and friction plates carried on the shaft. Rotation of the shaft causes rotation of a pinion which, in turn, rotates a gear associated with a chain drum to effect chain take-up and, therefore, application of the brakes. A holding pawl prevents rotation of the ratchet in a release direction. Rotation of the hand wheel in an opposite direction effects release of the clutch mechanism and consequently relaxation of tension on the chain for effecting a gradual release of the brakes. Quick release of the brakes is effected by a lever which, by rotation, causes disengagement of the collar from the pinion. |
