Abstract: The invention provides a hand-wrestling training device, comprising an elongated main base carrying at one of its ends a mounting means to which one end of a spring means is hingedly articulated; at least one mounting plate fixedly attached to the main base near the other end of the base; a head unit pivotably mounted in the mounting plate; a pusher arm fixedly attached at one of its ends to the head unit and provided with a plate element at the other one of its ends; a body movable in translation along the pusher arm, the second end of the spring means being articulated to the body; adjustment means for altering the mechanical advantage afforded to the user by moving the body along the pusher arm, thereby altering the effective length of the pusher arm, and a gripping handle hingedly attached to a portion of the head unit; the gripping handle, when turned downward, causing the pusher arm to be applied against the opposing force of the spring.

Abstract: The invention provides a chasing tool for repairing damaged internal threads, including a body provided with a bore; a handle retained in the bore with one degree of freedom in rotation, the handle being provided over at least part of its length with an internal thread; a cylindrical component having an external thread matching the internal thread of the handle; a tubular member fixedly attached to the body perpendicular to the axis of rotation of the handle and opening into the bore of the body and a lever tiltable about a pivot providing the lever with one degree of freedom in rotation, the cylindrical component being articulated to the lever and a cutter articulated to the other end of the lever, the cutter projecting from the tubular member.