Fluid-actuated workholder with a collet driven by a soft and thin bladder

摘要

A workholder to hold a workpiece, including a main body partially defining a fluid chamber, and a bladder carried by the main body with an interference fit, further defining the fluid chamber, and composed of an 80 to 100 durometer Shore A scale hardness polymer of a 12:1 to 18:1 diameter-to-wall-thickness ratio. Annular seals may further define the fluid chamber, and are disposed radially between the bladder and main body and axially adjacent the fluid chamber, and are composed of a 60 to 80 durometer Shore A scale hardness polymer. A collet is carried and driven by the bladder for gripping engagement with the workpiece.

主权项

1. A hydrostatic workholder to hold a workpiece, comprising:
a steel main body partially defining a hydraulic fluid chamber and including annular seal grooves axially adjacent the fluid chamber with annular seals, which are disposed therein to further define the fluid chamber and are composed of approximately 70 durometer Shore A scale hardness nitrile; a one-piece homogenously integral and circumferentially continuous annular bladder carried by the main body with an interference fit of approximately 0.001″, further defining the fluid chamber, composed of approximately 90 durometer Shore A scale hardness polyurethane and having approximately a 15:1 diameter-to-wall-thickness ratio; a steel collet having a plurality of generally longitudinally extending and circumferentially spaced-apart through slots carried by the main body and directly engageable with and generally radially displaceable by the bladder for gripping direct engagement with the workpiece; and excluding any metal baffle between the bladder and the collet.