Apparatus for active contact force control in machining and handling operations

A method comprising:

• providing an apparatus for active contact force control, the apparatus including:
• an upper flange to mount a production tool to the apparatus, where, when mounted, the production tool acts with a predefined contact force on a workpiece surface in a production process;
• a lower flange on a housing of the apparatus to mount the apparatus via the lower flange on a multi-axis machine which performs a spatial motion of the apparatus and the production tool when mounted to the lower flange of the apparatus;
• and
• a linear actuator in the housing, the linear actuator including a ball screw and at least one ball screw lever connected as a sliding joint to at least one linear guide having a first end portion in the housing, where the at least one linear guide limits motion of the ball screw only for axial motion along a linear axis of the linear actuator, and where the at least one linear guide has a second end portion that is connected, according to a first mechanical connection, to the upper flange,
• wherein the ball screw and the upper flange are connected according to a second mechanical connection that includes a force sensor to measure force by which the linear actuator is acting on the upper flange and thereby on the production tool,
• wherein the second mechanical connection between the ball screw and the upper flange is formed of a first spherical joint and a mechanical dissipative element between the force sensor and the upper flange, where the first spherical joint is configured to eliminate any non-axial load, and
• wherein the mechanical dissipative element includes an upper elastic dissipator and a lower elastic dissipator, with a disc plate between the upper and lower elastic dissipators, where the upper and lower elastic dissipators are fixed within the upper flange such that the disc plate forms a mechanical connection between the force sensor and the upper flange via the first spherical joint, and where the upper and lower elastic dissipators mechanically attenuate changes in contact force measured by the force sensor;
• and
• using the apparatus in the production process,
• wherein the production tool belongs to a group comprised of:
• a polishing tool, a grinding tool, a drilling tool, a milling tool, a sanding tool, a handling tool, or a tool used in electrochemical machining.

A system for active contact force control in machining and handling operations comprising:

• an upper flange to mount a production tool to the apparatus, where, when mounted, the production tool acts with a predefined contact force on a workpiece surface in a production process;
• a lower flange on a housing of the apparatus to mount the apparatus via the lower flange on a multi-axis machine which performs a spatial motion of the apparatus and the production tool when mounted to the upper flange of the apparatus;
• and
• a linear actuator in the housing, the linear actuator including a ball screw and at least one ball screw lever connected as a sliding joint to at least one linear guide having a first end portion in the housing, where the at least one linear guide limits motion of the ball screw only for axial motion along a linear axis of the linear actuator, and where the at least one linear guide has a second end portion that is connected, according to a first mechanical connection, to the upper flange,
• wherein the ball screw and the upper flange are connected according to a second mechanical connection that includes a force sensor configured to measure force by which the linear actuator is acting on the upper flange and thereby on the production tool,
• wherein the second mechanical connection between the ball screw and the upper flange includes at least a first spherical joint and a mechanical dissipative element between the force sensor and the upper flange, and is adapted to include a second spherical joint between the force sensor and the ball screw, where the first spherical joint is configured to eliminate non-axial load, and
• wherein the mechanical dissipative element includes an upper elastic dissipator and a lower elastic dissipator, with a disc plate between the upper and lower elastic dissipators, where the upper and lower elastic dissipators are fixed within the upper flange such that the disc plate forms a mechanical connection between the force sensor and the upper flange via the first spherical joint, and where the upper and lower elastic dissipators mechanically attenuate changes in contact force measured by the force sensor.