Abstract: The present invention provides a ratchet block with a block body 10 having a pair of side cheeks 11,12 and a sheave assembly 15 therebetween, which comprises a hub 16 supporting an annular sheave 17 for rotation about a principal axis. The ratchet block also includes a ratchet mechanism comprising ratchet teeth 19 on the sheave and a pawl 20 mounted on the hub 16 or a side cheek 11,12 for movement between an engaged setting, where the ratchet mechanism is active, and a free setting where the ratchet mechanism allows free rotation of the sheave. An actuator 25 is also mounted on the hub 16 or said side cheek 11,12 and linked to the pawl 20 to effect movement thereof between its engaged and free settings. Means are provided for pivoting the hub between loaded and unloaded limiting positions about an axis parallel to but spaced from the hub's principal axis. Spring means 33 are provided for biasing the hub 16 to said unloaded limiting position.

Abstract: A method of forming a U-shaped strap for a pulley block starts with providing a strip-like blank of a metal which may be work-hardened and having an elongate central region and two end portions extending one from each end of the two opposed ends of the central region. Such a blank may be formed by a stamping operation typically from a suitable grade of stainless steel. The central region of the blank is bent round into a U-shape with the two end portions substantially parallel. Either concurrently with the bending operation or subsequent thereto, the central region is subjected to a cold-forming operation in the transverse direction of the central region, to reduce the width thereof and to provide a radius to the long edges of that central region.

Abstract: A pulley block has a body which rotatably supports a sheave, the block having a mounting pin which extends through a bore in the block. The pin has an enlarged head disposed internally of the body to retain the pin in the bore. Rotation of the pin may be prevented by a releasable locking arrangement comprising a groove formed transversely across the enlarged head of the pin and a lock member rotatably mounted in a hole extending within the block adjacent the head of the pin. The lock member is profiled for rotation between a locked position where a part of the lock member locates in the groove in the head of the pin to restrain rotation of the pin and a free position where the lock member is free of the head of the pin so that the pin may rotate.

Abstract: A sheave assembly for use in a high performance pulley block has an inner race 14, a sheave 10 defining an outer race and a plurality of balls 13 arranged between the outer race of the sheave 10 and the inner race 14, so as rotatably to mount the sheave on the inner race. The inner race 14 is formed principally of a plastics material, but incorporates an annular insert 20 of metal, the outer surface of the insert extending parallel to the axis of the assembly, and defining an inner track for the balls 13. The axial width of the insert 20 is significantly less than, and typically 33% to 67% of, the diameter of the balls 13.