Mechanically actuated workpiece holder including a plastic collet

A mechanically actuated workpiece holding apparatus comprising:

• a collet at least partially composed of a plastic material wherein said collet includes a metal substrate that includes a cylindrical portion and a conical portion terminating an outboard end of the substrate and being coated with said plastic material, wherein the plastic material is adhered to the metal substrate by coating an adhesive on the metal substrate and then molding the plastic material around the metal substrate, said collet having at least one relief slot and a conical portion;
• a body supporting said collet;
• an actuator supported by said body and having a conical portion for cooperating with said conical portion of said collet, said actuator being linearly displaceable to impose a force on said collet such that linear displacement of said actuator is converted to radial displacement of said collet via said conical portions wherein said collet grips a workpiece;
• and
• an annular nose cap mounted to said body and wherein said body includes a radial flange, further wherein said collet is axially trapped between said nose cap and said radial flange,
• wherein said radial flange of said body includes at least one dowel pin mounted axially thereto and further wherein said collet includes a radially extending flange having a relief therein for cooperating with said at least one dowel pin.

A mechanically actuated arbor comprising:

• a collet at least partially composed of a plastic material wherein said collet includes a metal substrate that includes a cylindrical portion and a conical portion terminating an outboard end of the substrate and being coated with said plastic material, wherein the plastic material is adhered to the metal substrate by coating an adhesive on the metal substrate and then molding the plastic material around the metal substrate, said collet having at least one relief slot and a conical portion;
• a body supporting said collet;
• an actuator supported by said body and having a conical portion for cooperating with said conical portion of said collet, said actuator being linearly displaceable to impose a force on said collet such that linear displacement of said actuator is converted to radial displacement of said collet via said conical portions wherein said collet grips a workpiece;
• and
• an annular nose cap mounted to said body and wherein said body includes a radial flange, further wherein said collet is axially trapped between said nose cap and said radial flange;
• wherein said radial flange of said body includes at least one dowel pin mounted axially thereto and further wherein said collet includes a radially extending flange having a relief therein for cooperating with said at least one dowel pin.

A mechanically actuated workpiece holder for holding a workpiece comprising:

• a body;
• an actuator extending through at least a portion of said body and including a frusto-conical surface;
• and
• a collet carried by said body for cooperation with said actuator and including:
• a metal substrate that includes a cylindrical portion and a conical portion, and
• a plastic coating adhered and molded to said metal substrate to overlie said conical portion of said metal substrate,
• said collet also including opposed surfaces of revolution including a frusto-conical surface of said conical portion of said metal substrate for axial sliding engagement with said frusto-conical surface of said actuator and an oppositely disposed workpiece-engaging surface of said plastic coating, wherein said collet is adapted to be radially displaced by linear movement of said actuator for engaging said workpiece-engaging surface of said collet with the workpiece.