Abstract: A releasable tool holder (75) for quickly interchanging tools usable by a conventional robot (50) having one or more articulatable arms (60, 65, 70). The tool holder (75) is mounted to an arm (70) of the robot (50) and is provided with a plurality of variable fulcrum clamping levers (110) capable of engaging a surface (215) of a ring (205) mounting a preselected tool. A fluid motor (95) is connected to a translatable center link (105) that is pivotably attached to the variable fulcrum clamping levers (110) whereby when the motor (95) causes the link (105) to translate, the variable fulcrum clamping levers (110) engage the surface (215) of the tool mounting ring (205). A novel tool mounting ring (205) and a releasable fluid coupling (125) are also provided.