The present invention is believed to overcome a
number of problems that have often been associated
with prior art EDM's. An arrangement is described
herein which utilizes the pressurized dielectric ?uid
available on any EDM to drive a turbine wheel. This
wheel is operatively coupled, preferably through differ
ential gearing, to a drive shaft that is adapted to be
driven at a speed in the range from about 25 to 500 rpm
in the working range. The drive shaft carries a chuck
or collet which grips the electrode and enables the
same to also be rotated. To improve the effectiveness
of an EDM, the present invention also provides guide
means that are positionable to receive and support the
free end of an electrically conductive electrode. The
guide means disable any appreciable amount of motion
of the free end laterally of the axis of the electrode.
Moreover, these guide means are adjustable to provide
guided support of the free end of the electrode in the
immediate vicinity of a workpiece. This is an important
advantage since accurate positioning and guidance of
the tip of the electrode allows higher quality work to be
carried out.
In accordance with this invention, therefore, there is
provided apparatus for use on an electrode discharge
machine having a head and a supply of pressurized di
electric ?uid, comprising: a chuck for gripping and sup
porting an electrically conductive electrode, the chuck
being rotatably supported from the head of said ma
chine; and a turbine wheel rotatably mounted to effect
rotation of said chuck and electrode held therein, the
turbine wheel being in a housing which is in ?uid-?ow
communication with said supply of pressurized dielec
tric ?uid, and being so positioned as to transform pres