Folding joint for frame and worktable

A folding joint for frames and worktables comprising:

• a control portion and a joint portion;
• wherein the control portion includes a base, a moveable seat, and a hook while the joint portion includes an upper rotary arm and a lower rotary arm pivotally joined with each other, and an outer tube arranged at the upper rotary arm;
• wherein the base is provided with at least one penetrating moveable slot, a shaft inserted through the moveable slot, and a first return spring arranged between the base and the moveable seat;
• one end of the shaft is mounted to the moveable seat while the other end of the shaft is assembled with the hook;
• a second return spring is mounted between the base and the hook;
• wherein a lock cylinder is mounted in the outer tube;
• the lock cylinder is provided with a locked hook portion exposed outside the outer tube, and a third return spring disposed between the lock cylinder and the upper rotary arm;
• the hook is inserted through the locked hook portion which is used for control of displacement of the hook;
• the upper rotary arm is provided with a mounting hole through which the lock cylinder is inserted and the lower rotary arm is provided with a mounting groove in which the lock cylinder is mounted.