Compliant end effector

Abstract

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° 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.