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US RE28,747 EGranted
Method and apparatus for engraving characters
AssigneeNumerical Control Program Service, Inc.
InventorHerman Graboyes
Life of this patent
Estimating the term…
Abstract
A method and apparatus for engraving characters by the use of numerically controlled machine tools. The characters are engraved by moving a first machine tool about the outline of the desired character. Where the character has inside corners, a second numerically controlled machine tool is moved about the outline at the inside corner at a plurality of depths to reduce the radius of the curvature at the inside corner.
Claims8
A method of engraving inside corners of embossed characters with a numerically controlled machine tool device comprising the steps of:
- providing a rotatably mounted cutting tool having a tapered cutting portion;
- rotating said cutting tool;
- moving said cutting tool to an apex of an inside corner;
- positioning [the] a tip of said cutting tool at a plurality of successive depths with respect to [the] a land of said character at the apex of the inside corner ;
- moving said cutting tool with respect to the land of said character about [the] a desired outline of said character at the apex of the inside corner so that [the] an axis of said tool is moved vertically and horizontally at each of said depths so that the tool is spaced from [the] a desired borderline of said character a distance equal to [the] a radius of said tool in [the] a plane of said land of said character;
- whereby the radius on said inside corner is reduced to the radius of said tool in the plane of said land of said character when said tip of said tool is at a depth with respect to the land of said character which is the smallest of said successive depths.
3 more elements
A numerically controlled device for engraving;
- said device comprising a pair of rotatable cutting tools mounted closely together, said cutting tools each having a tapered cutting portion, a support member for an engravable member and control means for moving said support means with respect to said cutting tools, said control means causing said cutting tools to follow a desired pattern with respect to said engravable member, the first of said cutting tools having a larger diameter and being moved by said control means for removing large areas of excess material about said desired pattern, said second cutting tool and said engravable member being moved with respect to each other by said control means to remove the excess material at inside corners of said pattern not accessible by said first cutting tool, said cutting tools being positioned by said control means so that [the] an axis of each cutting tool is spaced from [the] an outline of said pattern in accordance with [the] a radius of the cutting tool in the plane of the top surface of the engravable member, said second cutting tool being positioned at a plurality of depths so that the radius at the inside corners of said pattern can be reduced to the radius of said second cutting tool adjacent its tip.
A method of engraving embossed characters with a numerically controlled machine tool comprising the steps of:
- providing a first rotatably mounted cutting tool having a tapered cutting portion;
- rotating said first cutting tool;
- positioning said cutting tool at a first predetermined depth with respect to [the] a top surface of said character equal to [the] a depth of said character;
- moving said cutting tool with respect to said character about [the] a desired outline of said character so that [the] an axis of said tool is spaced from [the] a borderline of said character by a distance equal to [the] a radius of said tool in [the] a plane of the top surface of said character;
- providing a second rotatably mounted cutting tool mounted adjacent said first cutting tool and having a tapered cutting portion with a smaller radius than said first cutting tool;
- moving said second tool with respect to said character so that said character is disposed below said second cutting tool;
- positioning said second cutting tool at a second predetermined depth intermediate of said first predetermined depth;
- and
- moving said second cutting tool with respect to said character about the desired outline of said character wherein excess material outside said desired outline remains so that the axis of said second tool is spaced from said borderline of said character by a distance equal to the radius of said tool at the top surface of said character.
6 more elements
Dependencies are inferred from the claim text.