US4367389A
Expired / Lapsed
US
⏱️ 0.0 years remaining
EDM System with abrasive finisher
Assignee: Japan Kinoko Research Center Foundation
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Filing: 1979-09-17
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Granted: 1983-01-04
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Expires: 1999-09-17
Abstract
Abstract An electrical discharge machining (EDM) apparatus is rendered capable of finishing machined workpiece surfaces by mounting an abrasive tool assembly on an electrode tool head juxtaposed with the machined workpiece as it is positioned fixedly on an EDM workpiece support. The tool assembly comprises a tool, a drive motor detachably attached to the tool holder and a coupling shank, the tool having a plurality of elongate pieces fixedly mounted on the shank so as to individually project axially therefrom and extending so as to collectively form a forwardly converging body of revolution rotatable about the axis of the shank, the generatrix of the body under revolution serving as an abrading surface. The EDM servo system may be used to sweep the machined surface with the tool body.
Inventors
- 👤 Kiyoshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:20
CPC Classifications
B; B23; B23H; B23H5/00
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
212 words
In an electrical discharge machine having a tool head for supporting an electrical-discharge-machining electrode and positioning it in an electrical-discharge-machining relationship with a workpiece, a support for carrying the workpiece, and machining-feed means for relatively displacing the tool head and the workpiece support to electroerosively machine the workpiece with the electrode, the improvement which comprises an abrasive-tool assembly mounted on said tool head for finishing the surface of said workpiece electroerosively machined and including a rotary shank, a plurality of elongate pieces having their individual free ends and fixed at their other ends to said shank so as to collectively form a forwardly converging body of revolution about the axis of said shank, and motor means for rotating said shank to revolve said elongate pieces about the axis of said shank whereby the generatrix of said body collectively formed by said pieces under revolution undergoes an expansion toward their free ends to serve as an abrading means in which said pieces slap against said electroerosively machined workpiece surface, said abrasive-tool assembly on said tool head being displaced by said machining feed means relatively to said workpiece on said workpiece support to sweep at least a selected portion of said electroerosively machined workpiece surface with said abrading means to abrasively finish the same.
Claim 2
Dependent Claim
212 words
In an electrical discharge machine having a tool head for supporting an electrical-discharge-machining electrode and positioning it in an electrical-discharge-machining relationship with a workpiece, a support for carrying the workpiece, and machining-feed means for relatively displacing the tool head and the workpiece support to electroerosively machine the workpiece with the electrode, the improvement which comprises an abrasive-tool assembly mounted on said tool head for finishing the surface of said workpiece electroerosively machined and including a rotary shank, a plurality of elongate pieces having their individual free ends and fixed at their other ends to said shank so as to collectively form a forwardly converging body of revolution about the axis of said shank, and motor means for rotating said shank to revolve said elongate pieces about the axis of said shank whereby the generatrix of said body collectively formed by said pieces under revolution undergoes an expansion toward their free ends to serve as an abrading means in which said pieces slap against said electroerosively machined workpiece surface, said abrasive-tool assembly on said tool head being displaced by said machining feed means relatively to said workpiece on said workpiece support to sweep at least a selected portion of said electroerosively machined workpiece surface with said abrading means to abrasively finish the same.
Claim 3
Dependent Claim
60 words
The improvement defined in claim 1 wherein said elongate pieces are composed of a substance selected from the group consisting of piano wire steel, mild steel, hardened steel, high-speed tool steel, stainless steel, brass, tungsten carbide, titanium carbide, tantalum carbide, titanium-nickel alloy, copper-beryllium alloy, iron, aluminum, nickel, tungsten, molybdenum, copper, copper-tin alloy, boron carbide, iron-chromium alloy, plastic, graphite and glass.
Claim 4
Dependent Claim
21 words
The improvement defined in claim 2 wherein said elongate pieces are each of a transverse size between 0.1 and 2 mm.
Claim 5
Dependent Claim
15 words
The improvement defined in claim 3 wherein said size is between 0.5 and 1 mm.
Claim 6
Dependent Claim
20 words
The improvement defined in claim 3 wherein said elongate pieces are arranged 3 to 20 in number along a circle.
Claim 7
Dependent Claim
40 words
The improvement defined in claim 5 wherein said elongate pieces individually project by a length l in mm from said shank and are arranged along the circle of a diameter D in mm, l/D being at least 0.5 to 1.
Claim 8
Dependent Claim
16 words
The improvement defined in claim 6 wherein said diameter D is between 2 and 8 mm.
Claim 9
Dependent Claim
15 words
The improvement defined in claim 1 wherein said elongate pieces are angular in cross section.
Claim 10
Dependent Claim
40 words
The improvement defined in claim 1, further comprising means for detecting contact pressure between said elongate pieces under revolution and said electroerosively machined workpiece surface and means for controlling said motor so as to maintain said contact pressure substantially constant.
Claim 11
Dependent Claim
24 words
The improvement defined in claim 9 wherein said detecting means comprises means for sensing electrical resistance between said elongate pieces and said workpiece surface.
Claim 12
Dependent Claim
19 words
The improvement defined in claim 9 wherein said detecting means comprises means for sensing the torque of said motor.
Claim 13
Dependent Claim
21 words
The improvement defined in claim 9 wherein said controlling means is adapted to control the rate of rotation of said motor.
Claim 14
Dependent Claim
19 words
The improvement defined in claim 9 wherein said controlling means is adapted to control the torque of said motor.
Claim 15
Dependent Claim
18 words
The improvement defined in claim 1, further comprising means for detachably mounting said elongate pieces on said shank.
Claim 16
Dependent Claim
64 words
The improvement defined in claim 14 wherein said shank comprises a head portion for holding said elongate pieces therewith and a shaft portion of a reduced diameter, said head portion having a recess and a plug member adapted to be bolted to said head portion within said recess for securely holding said elongate pieces between said plug member and the wall of said recess.
Claim 17
Dependent Claim
20 words
The improvement defined in claim 1 wherein said elongate pieces are at least in part coated with a hard substance.
Claim 18
Dependent Claim
30 words
The improvement defined in claim 1 wherein said elongate pieces at least in part have a plurality of hard substance, one spaced from the other, attached on the surface thereof.
Claim 19
Dependent Claim
19 words
The improvement defined in claim 1 wherein said elongate pieces have a hard substance sintered in a metal matrix.
Claim 20
Dependent Claim
34 words
The improvement defined in claim 1 wherein said elongate pieces comprises a non-metallic body selected from the group which consists of plastic, glass and graphite and having grits of a hard substance imbedded therein.
Claim 21
Dependent Claim
34 words
The improvement defined in any one of claims 16 to 19 wherein said hard substance is selected from the group which consists of diamond, boron nitride, ceramics, solicon carbide, metal oxides and metal carbides.
Claim 22
Dependent Claim
34 words
The improvement defined in claim 1 wherein said abrading means comprises a tubular member with a plurality of axially extending slits extending from one end thereof and equispaced therearound to form said elongate pieces.
Claim 23
Independent Claim
159 words
A method of finishing an electrical-discharge-machined workpiece surface, comprising the steps of: (a) electrical-discharge-machining a workpiece carried on a workpiece support with an electrical-discharge-machining electrode carried by a tool head; (b) forming an abrading tool with a rotary shank and a plurality of angularly spaced elongate abrasive pieces attached at one end to said shank and projecting therefrom to collectively form a forwardly converging body of revolution about the axis of said shank in a rest position; (c) mounting said tool on said tool head; (d) rotating said tool about said axis so as to spread the pieces of said body forwardly from said shank; (e) bringing said rotating tool in engagement with the electrical-discharge-machined surface of said workpiece on said support; and relatively displacing said tool head and said workpiece support to abrasively sweep said workpiece surface with the generatrices of said body serving as abrading means slapping against and finishing said surface while said tool is rotated.
Claim 24
Independent Claim
159 words
A method of finishing an electrical-discharge-machined workpiece surface, comprising the steps of: (a) electrical-discharge-machining a workpiece carried on a workpiece support with an electrical-discharge-machining electrode carried by a tool head; (b) forming an abrading tool with a rotary shank and a plurality of angularly spaced elongate abrasive pieces attached at one end to said shank and projecting therefrom to collectively form a forwardly converging body of revolution about the axis of said shank in a rest position; (c) mounting said tool on said tool head; (d) rotating said tool about said axis so as to spread the pieces of said body forwardly from said shank; (e) bringing said rotating tool in engagement with the electrical-discharge-machined surface of said workpiece on said support; and relatively displacing said tool head and said workpiece support to abrasively sweep said workpiece surface with the generatrices of said body serving as abrading means slapping against and finishing said surface while said tool is rotated.
Claim 25
Dependent Claim
19 words
The method defined in claim 22 wherein said tool is rotated at a speed between 500 and 50,000 rpm.
Claim 26
Dependent Claim
19 words
The method defined in claim 23 wherein said tool is rotated at a speed between 500 and 20,000 rpm.
Claim 27
Dependent Claim
19 words
The method defined in claim 23 wherein said tool is rotated at a speed between 5,000 and 50,000 rpm.
Claim 28
Dependent Claim
33 words
The method defined in claim 23 wherein said tool is rotated at a rate sufficient to sweep said abrasive pieces against said workpiece surface with a peripheral speed between 1 and 15 m/sec.
Claim 29
Dependent Claim
15 words
The method defined in claim 26 wherein said elongate pieces are angular in cross section.
Claim 30
Dependent Claim
32 words
The method defined in claim 22, further comprising the steps of: monitoring the force with which said body is urged against said surface; and controlling this force to maintain the same constant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-03 | 1986-07-05 | 1987-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-03 | 1990-07-05 | 1991-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-03 | 1994-07-05 | 1995-01-04 | $7700.00 | Window Closed / Lapsed |