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AssigneeSarclad International Limited
InventorsGareth A. Evans, David H. Savidge, Geoffrey Wilson
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Electrical discharge apparatus for producing on the surface of an electrically conductive workpiece a textured or matt finish comprises a plurality of electrodes each connectable to an electrical power source and each carried by a head which in use of the apparatus can be moved linearly of the workpiece with the electrodes each spaced at a predetermined distance from the workpiece surface. A characteristics of the voltage conditions present within the gap existing between the electrodes and the workpiece surface is monitored and, the head is moved towards and away from the workpiece surface to maintain the monitored characteristic within predetermined limits. Dielectric fluid is retained within the gap existing between the electrodes and the workpiece surface, and a series of discrete electrical discharges is promoted between each electrode and the adjacent workpiece surface to cause particles to be removed from the workpiece surface and produce a textured or matt finish thereto.
Electrical discharge apparatus for producing a textured or matt finish on the surface of a longitudinally extending, electrically conductive workpiece, the apparatus comprising a plurality of electrodes each connectable to an electrical power source and each carried by a head, a container for dielectric fluid which extends along a longitudinal segment of the workpiece to engage only a minor portion of the workpiece surface, and into which the head and the electrodes carried thereby protrude, means for effecting relative longitudinal linear movement between the head, the dielectric container and the workpiece with the electrodes each spaced from the workpiece surface to define a gap therebetween, means for monitoring the delay in time between the instant in time at which an electrical pulse voltage is applied to a selected one of several electrodes and the instant in time at which current flows across the gap, servo-means responsive to the monitored time delay and operable to move the head towards or away from the workpiece surface to maintain the monitored time delay within predetermined limits, and means for applying a series of discrete electrical voltage pulses of predetermined width and duration to each electrode to promote an electric discharge to an adjacent workpiece surface thereby to remove particles from the workpiece surface and produce a textured or matt finish thereto.
Electrical discharge apparatus for use with a rotatable cylindrical electrically conductive workpiece, the apparatus including a plurality of electrodes each insulated electrically one from another and each carried by a head, the head and dielectric container capable of being moved linearly along a longitudinal extent of the cylindrical workpiece with the electrodes spaced from the workpiece surface, a container for dielectric fluid which extends along a longitudinal segment of the workpiece to engage only a minor portion of the workpiece surface and into one side of which the head and the several electrodes carried thereby protrude and another side of which, in use of the apparatus, is closed by a rotating surface of the workpiece against which the container abuts, means for conveying dielectric fluid to and from the container for maintaining a predetermined level therein, and means for promoting a series of discrete electrical discharges through the dielectric fluid and between the several electrodes and the adjacent surface of the workpiece.
Electrical discharge apparatus for use with a rotatable cylindrical longitudinally extending electrically conductive workpiece, the apparatus including a plurality of electrodes insulated electrically one from another and each carried by a head, means for effecting relative longitudinal linear movement between the head, the dielectric container and the workpiece surface with the electrodes spaced from the workpiece surface, the apparatus further including a container for dielectric fluid which extends along a longitudinal segment of the workpiece to engage only a minor portion of the workpiece surface and into one side of which the head and the several electrodes carried thereby protrude and another side of which, in use of the apparatus, is closed by a rotating surface of the workpiece against which the container abuts, means for conveying dielectric fluid to and from the container for maintaining a predetermined level therein, and means for promoting a series of discrete electrical discharges through the dielectric fluid and between the several electrodes and the adjacent surface of the workpiece.
Dependencies are inferred from the claim text.