Abb Flexible Automation, Inc.

Douglas L St Onge

James A Hoffmann

Jesse Edward Schrimpf

The present invention relates to a compliant end effector for securing an implement or tool such as a spindle to an arm of an industrial robot. The end effector has an internal passageway that extends completely through the end effector for receiving the spindle. The end effector includes a mounting assembly, a gripping assembly, a compliant assembly and a biasing assembly. The mounting assembly has a mounting bracket that rigidly secures the end effector to the robotic arm. The gripping assembly has a support bracket that rigidly secures the spindle to the end effector. The compliant assembly joins the mounting assembly to the gripping assembly, and includes an internal collar with two sets of opposed pivot pins that form first and second pivot axes. The biasing assembly includes a sponge rubber biasing ring with a number of uniformly spaced springs that combine to bias the spindle into a normal biased position. The spindle has a reference axis that forms a reference line for the end effector when in this biased position. The collar and biasing ring also have openings that form a part of the passageway. The two-pivot axes allow the spindle to pivot in any direction relative to the reference line through 360&deg; around the reference line. The biasing assembly includes a stiffness adjustment assembly that produces a pre-load condition to adjust the amount of force needed to pivot the spindle out of its normal biased position. As the robotic arm moves the implementing along a uniform path of travel, the tool engages a workpiece with a substantially uniform surface or edge and cuts away unwanted burs or other unintended discontinuities from that surface or edge. However, the tool compliantly pivots relative to the reference line when the tool encounters a desired projection in the workpiece so that the tool does not gouge or cut away that desired projection.

Compliant end effector

This invention relates to a multi-purpose end effector for a robotic arm that moves a workpiece through an automated, multi-station, manufacturing operation. The end effector is particularly useful in a gear manufacturing operation in which a gear piece is annealed, ground and tested to ensure it meets desired specifications. The relatively lightweight and compact end effector securely grips the workpiece during multi-directional movements, and provides a degree of softness when loading the normally non-rotating workpiece onto a continuously rotating chuck or tool. The end effector is secured to the robotic arm by a cross-member equipped with three different gripping implements. A central gripping device extends from the middle of the cross-member, a loading arm extends from one end of the cross-member, and an unloading arm extends from the other end. Each gripping implement includes pneumatically controlled gripping fingers for holding the gear pieces. Each loading and unloading arm has a gripping cylinder and a rotatable sleeve for supporting its gripping mechanism. The loading arm has an extension cylinder for extending its gripping mechanism with a degree of softness or resiliency that helps prevent binding when the normally non-rotating workpiece engages the rotating chuck or tool.

Multi-purpose end effector for a robotic arm

A stabilizing fixture particularly suited for use with a robot end effector and holding relatively flexible components while they are cut, trimmed, or otherwise machined by the end effector. The fixture includes a chassis with wheels and a plurality of upwardly projecting posts that support an upper frame. The upper frame defines a platform for supporting, aligning, and stabilizing a flexible workpiece. The frame includes a two L-shaped brackets to support the workpiece and one or more vacuum-powered suction cups for tightly gripping and holding the workpiece against the brackets.

Compliant end effector for an industrial robot

A compliant end effector particularly suited for use with a robotic arm for accurately cutting and trimming the edges of a hot molded sheet of flexible plastic. The compliant end effector includes a mount secured to the robotic arm, an adjustment assembly pivotally attached to the mount, a guide that engages the plastic sheet near the area to be cut and trimmed, a tool for cutting and trimming the flexible sheet, and a pneumatic cylinder that biases the guide into engagement with the flexible sheet and presses the sheet against a rigid surface. The pneumatic cylinder moves the guide and tool through a range of positions as the robotic arm moves along a single path of travel down the length of the flexible sheet. The guide remains in contact with the flexible sheet despite warping or other imperfections in the stabilizing surface. The tool is fixed a predetermined distance from the guide to ensure that the plastic sheet is cut and trimmed within specific tolerances. By rotating the end effector, tabs and recesses can be formed in the edge of the flexible sheet while the robot moves along its single path of travel.

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Cudahy, WI, United States of America

Douglas L St Onge