Arm connection apparatus for an artificial model

An arm connection apparatus for an artificial model, comprising:

• a first and a second flat bases, providing a standardized fitting device to be fixedly attached to a shoulder and an arm of the artificial model respectively, each of the bases having a recess hole with a contour composed of a plurality of circular arc parts, and a plurality of threaded fixing holes being arranged to space apart circumferentially and to surround the recess hole;
• a lock disk, providing a lock hole with a polygon hole section extending from the lock hole such that a diameter of the lock hole being greater than a width of the polygon hole section, and having a plurality of fixing holes corresponding to the threaded fixing holes surrounding the recess hole so as to be fastened to the first flat base;
• a fixing disk, providing a central hole and a plurality of fitting holes too, and being fastened to the second flat base;
• and
• a lock bolt with an end, the end providing a circular insert head and a polygon lock part next to the insert head, extending a threaded rod part from the polygon lock part, and being fastened to the fixing disk by way of a nut with a washer;
• whereby, once the insert head of the lock bolt is inserted into the lock hole of the lock disk successfully due to the circular arc parts of the recess hole in the first base, the lock bolt is pushed toward the polygon hole section such that the polygon lock part of the lock bolt engages with the polygon hole section to connect the arm to the shoulder with an expected posture.