Locking device of a casing

摘要

A locking device applies to a casing having a cover and a seat for opening and closing of the casing. The locking device has a recess formed on an edge of the seat, a buckle downwards protruding from the cover and matching the recess, and a roller parallel-disposed in the recess and pivoted to the seat. The buckle has an accurate face smoothly against an upper slot of the roller for closing and opening the casing. A direction of lifting of the cover corresponds to a rotation of the roller so that a direction of applied force can be continuously unchanged to achieve an ergonomic effect.