| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of erroneous operation of inserting a cylinder lock into a keyhole in unlocking by a simple constitution, in a lock metal fitting 10 of a cover for an underground structure.SOLUTION: A lock metal fitting 10 includes: a bracket 11 attached to a cover; a key component 12 rotatably attached to the bracket; and a casing 13 covering the key component 12 and forming a keyhole for inserting an opening/closing key. The key component 12 includes: a shaft 12a having a connection part 12d with the opening/closing key on its head part; a cylindrical shutter part 12b surrounding the connection part; and a locking member 12c performing locking or unlocking by turning the shaft. A casing opening forming the keyhole of the casing and grooves 12g, 13d formed on an inner peripheral surface of the shutter part are shape-matched only when the locking member is in a locked state, thus enabling a cylinder lock to be inserted into the keyhole. Consequently, a cylinder lock is prevented from being erroneously inserted into the keyhole in an unlocking state. |
