EDM apparatus and method for performing EDM operation

An electric discharge machining module for forming a hole in a workpiece with an electrode, comprising;

• a module body defining a throughbore extending along an axis;
• a collet at least partially positioned within said throughbore, said collet including a first electrode passageway coaxial with said axis for receiving said electrode therethrough;
• and,
• a collet closer positioned within said throughbore for movement along said axis between a released position and an engaged position, said collet closer including a second electrode passageway coaxial with said axis for receiving said electrode therethrough, wherein said released position is defined by said collet closer disengaged from said collet, and said engaged position is defined by movement of said collet closer within said throughbore to engage said collet such that said collet grips said electrode.

A method for securing an electrode in an electric discharge machining module having a module body defining a throughbore therein, said throughbore extending along an axis and being closed at one end thereof, comprising the steps of:

• providing a spindle assembly at least partially positioned within said throughbore, said spindle assembly having a first electrode passageway therethrough;
• providing a piston assembly positioned within said throughbore for movement along said axis, said piston assembly having a second electrode passageway therethrough, said piston assembly cooperating with said closed end of said throughbore to define a piston passageway therebetween;
• positioning said electrode through said first electrode passageway of said spindle assembly and through said second electrode passageway of piston assembly, said electrode sealingly engaging a seal surrounding a portion of said second electrode passageway of said piston to inhibit leakage of said pressurizing fluid from said piston chamber through said second electrode passageway;
• and,
• supplying pressurizing fluid to said piston chamber to urge said piston assembly towards said spindle assembly, said spindle assembly including a collet portion shaped to be received by a collet closer portion of said piston assembly such that said collet grips said electrode.

An electric discharge machining apparatus for forming at least one hole in a workpiece comprising:

• module body defining at least one throughbore, wherein each one of said at least one throughbore comprises:
• a spindle assembly at least partially positioned within said throughbore for rotation, said spindle assembly including a first electrode passageway adapted to receive an electrode therethrough;
• and
• a piston assembly positioned within said throughbore for movement between a released position and an engaged position, said piston assembly including a second electrode passageway coaxial with said first electrode passageway adapted to receive said electrode therethrough, wherein a collet closer of said piston assembly engages a collet of said spindle assembly when said piston assembly is in said engaged position such that said collet grips said electrode for unitary rotational movement of said electrode and said spindle assembly.