Patent ID: 7793527

Claim:
A lock comprising: a handle including a shank having a recess in an inner periphery thereof; a hub including a pair of protrusions formed on an inner periphery thereof and angularly spaced from each other; a spindle rotatably mounted in the hub about a rotating axis extending along a longitudinal direction, with the spindle coupled to the handle to turn therewith; and a transmission member fixed to the handle to turn therewith, with the transmission member being a ring mounted around and securely engaged with the spindle, with the ring including an inner side facing the hub and an outer side facing away from the hub and spaced from the inner side in the longitudinal direction, with each of the inner and outer sides of the ring extending in a radial direction perpendicular to the rotating axis, with the ring further including an outer circular periphery extending between the inner and outer sides, with the ring further including a longitudinal hole through which the spindle extends, with the longitudinal hole extending from the inner side through the outer side in the longitudinal direction and having an inner circular periphery extending between the inner and outer sides and spaced from the outer circular periphery in the radial direction, with an arcuate stop extending contiguously with and perpendicularly to the inner side of the ring and parallel to the rotating axis in the longitudinal direction, with the arcuate stop being radially outwards of the longitudinal hole and extending concentrically with the longitudinal hole, and with the ring slideable between the protrusions of the hub when the handle is turned, with an arcuate engaging portion extending contiguously with and perpendicularly to the outer side of the ring and parallel to the rotating axis in the longitudinal direction and extending concentrically with the outer circular periphery, with the arcuate engaging portion spaced from the outer circular periphery in the radial direction towards the spindle, with the spindle received within and slideable relative to arcuate engaging portion, with the arcuate engaging portion directly received within the recess of the shank of the handle to allow joint rotation of the transmission member and the handle, wherein the arcuate stop engages with and is stopped by one of the protrusions of the hub after the handle has been turned through an angle by a rotational force, and wherein when a torque is applied to the handle that has been turned through the angle, the torque is imparted to the hub via the transmission member preventing the spindle from being damaged by the torque.