Lock and handle assemblies

A handle assembly having a first pivotal handle coupled to a first rotary member 5A and a second pivotal handle couple to a second rotary member 5B; first and second rotary members having respective detachable drive elements such as screw threaded lugs. The first and second drive elements/pins when installed are operable to retract a latch in response to rotation of the respective handle; when the drive member/pin is removed the handle is uncoupled from the latch such that rotation of the handle is ineffective to retract the latch. Preferably the drive members are a screw threaded pin which engages within an arcuate slot in a common drive plate which drives the latch to the retracted position; the arcuate slots are preferably diametrically opposite each other and provide for lost motion over limited range of movement. The assembly may be part of a multipoint locking mechanism.