Patent ID: 8047348
Filing Date: 2011-11-01
Classification: A61P,B66D,F16D

Abstract:
1. A clutch structure for manual hoists, comprising: a driven wheel adapted to drive a wind device in the manual hoist, the driven wheel including a round body and a collar centrally and longitudinally extending from the body, a threaded portion formed on a free end of the collar, one side of the body having multiple dimples equally defined in a circle that is a concentric circle relative to the body, a steel ball partially received in each of the multiple dimples; a ratchet rotatably sleeved on the collar of the driven wheel for selectively driving the driven wheel when the load of the hoist is smaller than a connecting intensity between the ratchet and the driven wheel, the ratchet having a series of teeth formed on an outer periphery thereof, the series of teeth adapted to be engaged to a handle such that the ratchet is driven and rotated when the handle is reciprocally operated, multiple curved guide grooves equally defined in one side of the ratchet and form a concentric circle relative to the ratchet, each guide groove communicating with a corresponding one of the multiple dimples after assembling the ratchet such that the steel ball is received between the corresponding guide groove and dimple; at least one resilient member sleeved on the collar and abut against the ratchet for providing a lateral force to the ratchet and enhancing the connecting intensity between the ratchet and the driven wheel; and a nut screwed onto the threaded portion of the collar to prevent the ratchet and the at least one resilient member from detaching from the driven wheel, the nut provided to compress the at least one resilient member for promoting and adjusting the connecting intensity between the ratchet and the driven wheel; wherein each guide groove is drop-shaped, and the depth and the width of each of the multiple guide grooves form a direct ratio, the maximum of the total depth of the dimple and the guide groove slightly greater than the diameter of the steel ball, and the radian of each of the multiple guide grooves being 30 degrees.