Patent ID: 8419310

Claim:
A mechanical joint system, comprising: a first joint defining a pivot hole and a joint receiving hole communicating with the pivot hole; an arm being rotatable relative to the joint, the arm comprising a pivot portion and a pivot hole defined in the pivot portion, the pivot portion being received in the joint receiving hole, and the pivot hole of the arm and the pivot hole of the joint being aligned along a same axis; an engaging member comprising a pivot shaft and a fixing member, the pivot shaft comprising a shaft head and a shaft portion extending from an end of the shaft head, the shaft head being inserted into the pivot hole from an end thereof, the fixing member being inserted into the pivot hole from an opposite end thereof, and fixed relative to the pivot shaft; a plurality of teeth extending from an outer surface of the shaft portion of the pivot shaft; wherein the first joint further comprises a first flange portion and a second flange portion formed in the pivot hole, the first flange portion is positioned adjacent to a first sidewall in the first joint receiving hole and the second flange portion is positioned adjacent to a second opposite sidewall in the first joint receiving hole; a plurality of locking grooves are defined in the second flange portion; the pivot shaft of the engaging member further comprises a plurality of latching rims circling an end of the shaft portion and connected to an end of the shaft head, and the pivot shaft is fixed relative to the first joint when the latching rims received in locking grooves of the first joint; and the arm defines at least one non-through hole in an inner surface of the pivot hole, the latching member is a steel ball received in the at least one non-through hole for engaging with the teeth, the mechanical joint system latching member further comprises at least one compressed spring received in the at least one non-through hole, an end of the at least one compressed spring is fixed to a bottom surface of the at least one non-through hole and an opposite end of the at least one compressed spring is fixed to the latching member.