Patent ID: 7118301

Claim:
A connection assembly for boxes comprising: a base plate and a cover plate, a connection support which connects integrally the base plate and the cover plate in spaced, generally parallel relation to define a predetermined space therebetween; a rotary shaft member which is supported pivotably by the base plate and the cover plate at a perpendicular location; an engage piece which is installed into the predetermined space generally parallel to the base plate and cover plate, the engage piece being capable of rotating together with the rotary shaft member, a return spring having a center part wound around the rotary shaft member and having two ends supported one by a spring pressure part of the rotary shaft member and one by an engage piece of the base plate; a fixed shaft at one side of the base plate, a lock piece locking the engage piece, the lock piece being supported pivotably by the fixed shaft and having an engage part which projects from an upper surface of the base plate; and a spring which is attached to the fixed shaft, capable of biasing the lock piece to an engagement direction.