Patent ID: 7251129

Claim:
A two-way auto-locking tablet PC hinge, comprising: a hinge base coupled to a base of a tablet PC; a central rotational frame coupled to the hinge base for rotating the central rotational frame on the hinge base; a shaft fixed with the central rotational frame; a fixing bracket rotatably coupled to the shaft and further coupled to a display of the tablet PC; a rotational cam rotatably coupled to the shaft and fixed on the fixing bracket so as to synchronously rotate with the display; a fixed cam for engaging with the rotational cam and slidably coupled to the shaft; two positioners symmetrically formed between the rotational cam and the fixed cam so as to lock the display to the base when the display is parallel to the base; a threaded nut screwed on one end of the shaft to push the fixed cam; and an intermediate washer locked to the shaft and disposed between the threaded nut and the fixing bracket so as to prevent the threaded nut from being loosened when the fixing bracket is rotated.