Differential pulley were. Next, the downward force acting on the lower pulley equal the upward forces acting on it, so Additionally, there is no net torque or moment around the compound pulley, so the clockwise torque is equal to the anticlockwise torque: Substituting "F" and "F" from the above equations, Rearranging gives As "F" = , Finally, the mechanical advantage, = or . Differential pulley A differential pulley, also called "Weston differential pulley", sometimes "chain hoist" or colloquially "chain fall", is used to manually lift very heavy objects like car engines. It is operated by pulling upon the slack section of a
Hook Estate and Kennels and grassland (c.1931), purchased by the Greyhound Racing Association (GRA), soon after the first oval track racing arrived in the United Kingdom. The kennels were located on what was formerly Hook Farm, south of Hook Wood. The mansion 'Hook House' or 'The Hook' served as a base for some of the senior staff including the kennel manager and veterinary surgeon and the Hook Cottages and newly built Hook villas were divided among the trainers and their families attached to the GRA's racetracks. The kennels opened with 150 employees and there was a separate kennel block for each of the original