International Business Machines Corporation

Jane A Gregory

Henry E Aviles

Hugo A Panissidi

Henry E Wattenbarger

A gripper pad or gripper tool changer for a multi-axis manipulator is provided which is capable of automatically attaching in locked position a selected pair of a plurality of gripper pads or tools to the fingers of a gripper. Each pair of gripper pads or tools are mounted in a holder mechanism which is attached to a surface within the work envelope of the manipulator. The pairs of gripper pads or tools are picked up from the holder and attached and locked to the gripper fingers by controlled movement of the manipulator. A pair of gripper pads or tools are returned to the holder by controlled maneuvering of the gripper into the holder such that unlocking means associated therewith provide unlocking of the gripper pads or tools from the gripper fingers so that the gripper pads or tools can be detached from the gripper fingers. Error detection of missing or displaced finger tools in a pickup operation is provided.

Manipulator gripper tool changing apparatus

A multi-degree of freedom force transducer is provided for measuring forces applied to gripper fingers in a manipulator when grasping an object therebetween. The transducer includes a pair of force sensor assemblies rigidly connected at a first end to a respective finger and at a second end to a drive member for the gripper. A plurality of parallel beam structures are contained in each of the force sensor assemblies, each consisting of a pair of flat parallel flexure members, each member bridging opposite sides of a gap in the structure. These parallel beam structures are oriented so that the axis perpendicular to the planar surfaces of the parallel flexure members are orthogonal to one another, providing the capability of measuring the force applied to an object held by the gripper in the X, Y and Z axial directions. A strain gage of a pair of strain gages is located at a predetermined opposite maximum flexure point of each flexure member of said parallel beam structures, so as to measure the flexure of the member at the predetermined flexure points, which flexure is indicative of the force vector along the axis perpendicular to the parallel flexure members. In another embodiment the junction between the flexure member and the wall of the strain gage assembly is radiused or curved so that the maximum flexure point is spread out, giving longer life and enhanced measurement accuracy.

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Boca Raton, FL, United States of America

Jane A Gregory