Patent ID: 7549684

Claim:
A latch mechanism for locking a cover unit to a base unit, the latch mechanism comprising: a latching member configured for being slidably installed in the cover unit, the latching member comprising a main body and a hook extending from the main body for engaging with the base unit; and a manipulable integrally formed button configured for being rotatably fixed to the cover unit, the button comprising a knob accessible from outside the cover unit for operating the button, and a driving surface operatively engagable with the main body of the latching member for cooperatively transforming rotating movement of the button into linear movement of the latching member thereby disengaging the hook from the base unit; wherein the main body of the latching member comprises a recessed section, and the driving surface of the button urges against the recessed section to move the latching member, the main body of the latching member further comprises a concave section, the concave section and the recessed section share a protruding edge, the driving surface of the button is arcuate in construction and urges against the protruding edge; the button further comprises an arcuate mating surface adjoining the driving surface and fittingly engagable in the concave section, the mating surface extends a predetermined length around a pivot axis of the button, the driving surface is defined with two ends thereof communicating with the mating surface and a circumferential surface of the button, and an acme of the mating surface is nearer to the pivot axis than an acme of the driving surface to the pivot axis.