Video cassette closing device

摘要

The underside, or back, of a video cassette (6) has a circular opening (4) to accept a cylinder lock (1). When the key (3) is turned, the two cylinders (2) are pushed into the rectangular orifices (5) to produce a locking action. On the opening (4) there is a recess (7) with a sunken-head screw (9), so that the cassette can be dismantled and opened. There is also a security projection engaging in the recess as the cylinder lock is fitted, and this covers the sunken-head screw, making it inaccessible.