A mechanical clutch for mechanically connecting and disconnecting a rotational drive member and a rotational driven member of a locking mechanism. The mechanical clutch includes a drive and a driven member for rotation around an axis of rotation, a clutch pin which engages with the drive and or driven member to mechanically and rotationally link the drive and driven member to one another, and a clutch pin engagement surface provided on the or each clutch pin. A corresponding clutch pin engagement surface is also provided on the drive or driven members such that, when the engaged drive and driven members are rotated against a magnitude of rotational resistance (which is below a threshold magnitude of rotational resistance) the respective clutch pin engagement surfaces of the clutch pins and drive or driven members will co-act with one another to retain said rotational connection between the drive and driven member. When the drive and driven members are rotated against a magnitude of rotational resistance (which is above the threshold magnitude of rotational resistance) the respective clutch pin engagement surfaces of the clutch pins and drive or driven members will co-act with one another to urge the clutch pins out of rotational driving engagement between the drive and driven member.

A lock (100) comprising a plurality of buttons (111), each button (111) having an axis along which each of the buttons (111) may be axially pressed between an un-pressed position and a pressed position, a locking plate (120), an actuator (114) configured to drive the locking plate (120): a locking mechanism (122) having an unlocked and a plurality of locked states, the plurality of locked states corresponding to different selections of buttons (111) having been pressed into their pressed positions; and a latch (117); in which, when the locking mechanism (122) is in the unlocked state, the locking plate (120) can be driven by the actuator (114) from a locked position into an 10 unlocked position so as to disengage the latch (117) and unlocking the lock (100), but when the locking mechanism (122) is in one of the locked states, the locking mechanism (122) prevents the locking plate (120) being moved by the actuator (114): the lock (100) further comprising a decoupling mechanism (200) by means of which the actuator (114) can drive the locking plate (120), the decoupling mechanism (200) being arranged to decouple the actuator (114) from the locking plate (120), so as to reduce any feedback indicative of which of the unlocked states the locking mechanism (122) is in passing from the locking plate (120) to the actuator (114). In one example, the decoupling mechanism (200) comprises a driven member (201) driven for motion by the actuator (114), a first resilient member (202) connecting the driven member (201) with the locking plate (120) and a second resilient member (203) connecting the locking plate (120) to a fixed member fixed relative to a housing of the lock (100); and in which the first (202) and second (203) resilient members each have a spring constant, with the spring constant of the first resilient member (202) being greater than the spring constant of the second resilient member (203).

A lock includes a housing in which a combination lock is received. The combination lock is unlocked when the combination unit of the combination lock is located at an unlocked position. The combination lock has a cam pin which is operated when the combination lock is unlocked and locked. A button is pushed to drive a cam which is located beside the combination lock. When the combination lock is locked, the cam pin is connected to the restriction hole to restrict the cam, and the latch is in its locked status. When the combination lock is unlocked, the cam pin is removed from the restriction hole. When the button is pushed, the cam is rotated to release the latch from the room of the housing. The combination of the combination lock can be changed by operating the operation bar when the combination lock is unlocked.

A combination lock is disclosed. A lock seat includes a base and a lock core, and numeral wheels are arranged spacedly on the base. Each numeral wheel includes a lower gear and an upper gear, and part of each lower gear protrudes from the base. An anti-detection piece includes a main rod and branch rods. Each branch rod is located on one side of each upper gear. A panel covers the base, and numeral holes and an opening are defined on the panel. A knob is arranged on one side of the anti-detection piece. The knob is connected to the lock core and protrudes from the opening.