ECM trepan of bars
AssigneeLehr Precision, Inc.
InventorsTerry Lievestro, John Reynolds
Life of this patent
Estimating the term…
Abstract
An ECM apparatus includes a stationary cathode tool having a passage, and a drive mechanism for moving a bar-shaped workpiece through the passage of the cathode tool while simultaneously rotating the workpiece. Electrolyte flows, from a manifold on one end of the cathodic tool to a manifold at the other end, through the passage, between the wall of the passage and the workpiece. An electric current is simultaneously established in the electrolyte, between the wall of the passage and the workpiece. The internal shape of the cathodic tool wall has a gradual transition from a circular entry opening to a lobed exit opening, and lobes formed in the wall of the tool are shaped so that they twist in the direction of workpiece rotation, in order to form helical lobes in the workpiece.
Claims19
An apparatus for electrochemical trepan machining of a workpiece having a large length-to-diameter ratio, to a desired product, the apparatus comprising:
- a cathodic tool having a through passage for receiving a workpiece, the passage having an entry opening and an exit opening, the entry opening corresponding in shape to, and being slightly larger than, the cross-section of the workpiece, and the exit opening corresponding in shape to, and being slightly larger than, the cross-section of the desired finished product, the cross-sectional shape of the through passage having a gradual transition from the shape of the entry opening to the shape of the exit opening, along the length of the through passage;
- a manifold connected to the cathodic tool adjacent one of said entry and exit openings for directing electrolyte through said through passage of the cathodic tool, about a workpiece moving through said through passage;
- a drive mechanism that moves the workpiece through said passage of the cathodic tool and said manifold, such that a first amount of material may be removed from a first predetermined portion of the workpiece at a first rate of removal and a second amount of material may be removed from a second predetermined portion of the workpiece at a second rate of removal;
- supports for holding the workpiece as it moves through the cathodic tool;
- and
- an electric power supply connected to the cathodic tool and connectible to the workpiece, wherein the drive mechanism stops the movement of the workpiece through the cathodic tool at a predetermined position along the workpiece, wherein the stop of the movement of the workpiece provides a bearing journal.
An apparatus for electrochemical trepan machining of a workpiece having a large length-to-diameter ratio, to a desired product, the apparatus comprising:
- a cathodic tool having a through passage for receiving a workpiece, the passage having an entry opening and an exit opening, the entry opening corresponding in shape to, and being slightly larger than, the cross-section of the workpiece, and the exit opening corresponding in shape to, and being slightly larger than, the cross-section of the desired finished product, the cross-sectional shape of the through passage having a gradual transition from the shape of the entry opening to the shape of the exit opening, along the length of the through passage;
- a manifold connected to the cathodic tool adjacent one of said entry and exit openings for directing electrolyte through said through passage of the cathodic tool, about a workpiece moving through said through passage;
- a drive mechanism that moves the workpiece through said passage of the cathodic tool and said manifold, such that a first amount of material may be removed from a first predetermined portion of the workpiece at a first rate of removal and a second amount of material may be removed from a second predetermined portion of the workpiece at a second rate of removal;
- supports for holding the workpiece as it moves through the cathodic tool;
- and
- an electric power supply connected to the cathodic tool and connectible to the workpiece, further comprising a blank which extends through the cathodic tool.
Dependencies are inferred from the claim text.