Rotary limit switch

A rotary limit switch works on the principle of a worm
drive . A worm drive mechanism is suited so that
enough torque is generated to move the attached gears within the limit switch. The shaft of the limit switch has threads which are matches and attached to a helical gear. As the shaft rotates , the gear rotates according to the gear ratio. The gears are attached to a cam mechanism which rotate along with the central gear, a rotary limit switch has a minimum of two cams , one for setting the upper limit of the hoist machinery and one for setting the lower limit of the hoist machinery.