METHODS OF MAKING SHARP-EDGE CUTTING ELEMENTS

• US 3,762,243 A
• Filed: 03/13/1972
• Issued: 10/02/1973
• Est. Priority Date: 03/13/1972
• Status: Expired due to Term

• Current Assignee: Richard A. Borrkfield
• Original Assignee: Richard A. Borrkfield
• Inventors: Borrkfield, Richard A.
• Primary Examiner(s): Hinson, Harrison L.
• Application Number:
  US05/233,967
• Time in Patent Office: 568 Days
• Field of Search: 76/14A,14R 204/142,143
• US Class Current: 205/122
• CPC Class Codes: B23H 5/08 Electrolytic grinding
• CPC Class Codes: B23H 9/08 Sharpening

Abstract

Methods of making sharp-edged cutting elements are disclosed in which one of two opposite surfaces of a work piece has a thin layer added thereto. The work piece is of a metal that is capable of having a cutting edge formed thereon and is subject to electrolytic attack. The added layer is less than 0.010 of an inch in thickness and is of a material capable of being fine ground. Work piece material is removed electrolytically from the other of said work piece surfaces in an area exposing an edge of the added layer which is simultaneously fine ground with an abrasive in the order of and preferably less than 50 microns in size. The material of the added layer is so inert to the electrolyte that it is substantially unaffected thereby while being fine ground.

Claims

1. The method of making a sharp-edged cutting element that comprises the steps of adding a thin layer to at least a portion of only one of two opposed surfaces of a work piece of a metal subject to electrolytic attack and capable of having a cutting edge formed thereon and useful as blade and cannula stock, the added layer being less than 0.010 of an inch in thickness and of a material capable of being fine-ground to establish the sharp cutting edge of the element and selected from the group consisting of platinum, rhodium, ruthenium, palladium, osmium, titanium, tantalum and their alloys, oxidized aluminum, and ceramics, and electrolytically removing work piece metal from the other of said work piece surfaces in an area to expose the edge of said added layer at said portion of the work piece and simultaneously fine-grinding the exposed edge of the layer with an abrasive whose maximum size is in the order of 50 microns to so taper it as to form said sharp cutting edge, the material of said added layer being so inert with respect to the action of the electrolyte as to be substantially unaffected thereby while being fine ground.

2. The method of claim 1 in which the work piece material is a metal selected from the metal group consisting of steel, aluminum, and their alloys.

3. The method of claim 1 in which the work piece material is aluminum and the added layer is the anodized product thereof.

4. The method of claim 1 in which the work piece material is stainless steel and the added layer is selected from the following materials of the group rhodium, iridium, and platinum.

5. The method of claim 1 in which the work piece is tubular, the added layer extends to one end thereof, the electrolyte flows through the tubular work piece from the other end thereof to said one end and the abrasive is carried by the electrolyte.

6. The method of claim 1 in which the surface layer is established chemically.

7. The method of claim 1 in which the surface layer is formed by electroplating.

8. The method of claim 1 in which the surfaces are established by rolling the material of the surface layer on the base layer.

9. The method of claim 1 in which the surface layer is produced electrochemically.

10. The method of claim 1 in which the surface layer is formed by flame spraying.

11. The method of claim 1 in which the step of electrolytically removing work piece material and simultaneously fine grinding the exposed edge of the added layer is effected with a rotatable electrode provided with a working face in which the abrasive particles are embedded and against which a stream of the electrolyte is directed.

12. The method of claim 1 in which the step of electrolytically removing work piece material and simultaneously fine grinding the exposed edge of the added layer is effected with a rotatable electrode provided with a working face against which a stream of the electrolyte is directed, the abrasive particles being carried by the stream.