The History and Geography of Human Genes

A key trap lock structure, which is designed to be operated so that outstanding keys, desired to be retrieved by building personnel, can be trapped in the lock after insertion and prior to intended door opening. The lock is designed such that the central bolt or cylinder member, upon being rotated by key through a predetermined arc, will, by it's catch element springing outwardly, engage a slot in the housing so that the cylinder member cannot be turned and the key cannot be retrieved. Thus, the unauthorized user must leave the key in the lock. Subsequently, maintenance or building personnel, by the means shown, can reload the catch element so that the cylinder member can be turned to the original position for insertion. Thereafter, appropriate means can be installed to retain the catch element in the non-catch, lock-operative position.