Cellar window shaft grating security lock - has U=shaped shackle and release member accessible only from inside

摘要

A retaining member is detachably connected to an anchoring element fixed to a shaft wall, and secured by a lock, on a grating covering a cellar window shaft. The lock (58) has a lock unit (66) coupled to a U-shaped stirrup-piece (69). It is fitted with a closing and release member (76), easily set from inside the shaft. The lock is virtually inaccessible from outside the grating (16).