US 5,522,608 A · Self compensating and geometrically centering chuck

Abstract

A method and apparatus for a self compensating and geometrically centering jaw type chuck for engaging and retaining a workpiece, particularly an asymmetric workpiece, wherein a geometric center of the workpiece is aligned with a rotation axis of the chuck. The chuck includes two opposing jaws each of which is rotatable about a pivot pin extending from a radially adjustable jaw slide. Each jaw includes an outer end that is slidably and rotatably coupled to a rotatable ring symmetrically disposed about the rotation axis by a synchronizing pin having a first end rotatably disposed on the rotatable ring, and a second end, slidably engagable with the outer end of the jaw. The rotation of one jaw about the pivot pin rotates, in synchronism, the rotatable ring and the other jaw to maintain the geometric center of the asymmetric workpiece in alignment with the rotation axis of the chuck. The jaw slides are radially adjustable to open and close the jaws by reciprocating a piston along the rotation axis of the chuck. The piston is coupled to the jaw slides by two opposing cranks rotatable about a crank pivot which provides a levering action to adjust the jaw slides. A passive spring assembly applies a force to the piston which biases the jaws in the closed position. The jaws are opened in response to an applied counter force applied to the piston by pneumatic or hydraulic actuation.

Claims8

Dependent claims

A chuck for engaging and retaining a workpiece, the chuck comprising:

at least two opposing jaw slides disposed about a fixed rotation axis, each jaw slide having a pivot pin extending therefrom, parallel to and symmetrically arranged about the rotation axis, wherein each jaw slide is adjustable to move the pivot pins, in synchronism, along a radial of the rotation axis;
a jaw rotatably disposed about each pivot pin of the jaw slide, each jaw having an outer end with a sliding engagement surface, and each jaw having an inner end with two workpiece engaging surfaces, wherein each jaw is adjustable along a radial of the rotation axis in agreement with movement of the pivot pins, wherein the jaws may be opened and closed so that the workpiece engaging surfaces may engage and retain a workpiece;
a rotatable ring symmetrically disposed about the rotation axis;
and
two synchronizing pins each having one end pivotally disposed, in a diametric relation, on the rotating ring, each synchronizing pin having a second end coupled to the first end, the second end of each synchronizing pin slidably engagable with the sliding engagement surface of a corresponding jaw, wherein the second end of each pin is slidable in relation to the jaw when the jaw is adjusted along a radial of the rotation axis, and wherein the rotation of one jaw about a pivot pin rotates, in synchronism, the rotatable ring and the other jaw to accurately align a geometric center of the workpiece with the fixed rotation axis.

2 more elements

Dependencies are inferred from the claim text.

Self compensating and geometrically centering chuck

Life of this patent

Self compensating and geometrically centering chuck

Life of this patent

Abstract

Claims8