Apparatus and method for preventing a vehicle being driven away from a loading bay

A method of preventing a vehicle from being driven away from a loading bay during loading/unloading, comprising the sequential steps of:

• applying to a vehicle at a loading bay a safety device which prevents the vehicle from being driven away from the loading bay;
• locking the safety device to prevent removal of the safety device, by means of a key which is prevented from being removed from a lock of the safety device until the safety device is locked;
• removing the key from the locked safety device;
• and
• using the key to enable use of the loading bay, thus simultaneously trapping the key in a second interlock mechanism so that it cannot be used to unlock the safety device, the key remaining so trapped until it is used to disable use of the loading bay,
• and wherein the safety device comprises a trapped key safety interlock device for use with a coupling that comprises a body provided with a face seal, a rim on one side and a projecting spur on the diametrically opposite side, the safety device including a coupling part which is complimentary to the said coupling and which comprises a body portion having a rim portion on one side for engagement with the spur of the said coupling and having a spur portion on the diametrically opposite side for engagement with the rim of the said coupling, the rim portion accommodating a release mechanism for selectively enabling and disabling a key retention mechanism of the lock within the device, the key retention mechanism having a key retention condition for trapping the key in the lock of the safety interlock device and a key releasable condition in which the key, when in the lock, can be removed, wherein the release mechanism comprises a primary release mechanism and a secondary latching mechanism, both being required to be moved and thus actuated by the spur of the coupling to disable the key retention mechanism for putting the key retention mechanism in the key releasable condition, the secondary latching mechanism being for resisting movement and thus actuation of the primary release mechanism by the spur of the coupling until it is actuated itself by the spur of the coupling.