Mechanically actuated hydrostatic tool holder

A collet to releasably retain a tool having a central shank and constructed to be received within a bore of a tool holder which has a threaded portion at one end thereof comprising:

• a body;
• a central bore in the body;
• a deflectable sleeve received in the central bore and constructed to receive the shank of the tool therein;
• an annular chamber defined between the sleeve and the body and constructed to receive a fluid therein;
• at least one piston communicating with the chamber to pressurize fluid in the chamber;
• and
• a nut received on the threaded portion of the tool holder and engageable with each piston to displace each piston and thereby pressurize the fluid in the chamber whereby the pressurized fluid in the chamber urges the sleeve into engagement with the shank of the tool to hold the tool in the collet and urges the body into engagement with the tool holder.

An apparatus to releasably retain a tool having a central shank and constructed to be received within a bore of a holder which has a threaded portion at one end thereof comprising:

• a body;
• a central bore in the body;
• a pressure sleeve received in the central bore and constructed to receive the shank of the tool therein;
• an annular chamber defined between the sleeve and the body and constructed to receive a fluid therein;
• at least one fluid pressurizing member communicating with the chamber to pressurize fluid in the chamber;
• and
• an actuator threadably received on the threaded portion of the holder and moveable relative to and capable of displacing each fluid pressurizing member whereby displacement of each fluid pressurizing member pressurizes fluid in the chamber to urge the sleeve into engagement with the shank of the tool to hold the tool in the body and urges the body into engagement with the holder.