Abstract: An interlock system comprising: a first lock including a first lock memory configured to store one or more virtual keys; and a first key including a first key memory configured to store one or more virtual keys, wherein the first lock is configured to be actuated between a first condition and a second condition, when a first virtual key stored in the first key memory is transferred to the first lock memory, by engagement of the first key and first lock, and movement of the first key with respect to the first lock.

Abstract: A control method and apparatus for a door-locking mechanism which includes an electrically-released latch, to lock the door closed. A processing unit sources first and second data streams each of a repeating string of binary data, the two strings being of the same bit length and bit rate, the processing unit also having two sensing inputs. A normally-open first switch is associated with the latch and connects the first data stream to the first sensing input other than when the latch is released, and a normally-open second switch is associated with the door and serves to connect the second data stream to the second sensing input so long as the door remains closed. A normally-closed third switch is also associated with the door and serves to link together the first and second sensing inputs when the door is not closed. The processing unit outputs a signal indicative of an error condition should the data stream which appears at either sensing input not be the expected stream.

Abstract: An interlock unit (10) for use with at least one other like unit (11) to form an interlock mechanism has a top face (13) and opposed pairs of side walls (12) with at least one runner bar (17, 18) mounted in the unit for lateral sliding movement. An actuator (14, 15, 22) is supported on the top face (13), to effect lateral sliding movement of the runner bar (17, 18). One wall of the unit is provided with one part (27) of a two-part connector with the other part (33) on the opposed wall whereby two similar units may be joined together by relative sliding movement of the two units in the plane of the side walls (12). Joining together of two units (10, 11) in this way also joins together the runner bars (17) or (18) of the two units such that sliding motion of the runner bar (17) of one unit (10) is transferred to the runner bar (17) of the connected unit (11), for at least one direction of sliding movement of the runner bars (17).