US3594536A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the spark machining of workpieces and a spark-machining electrode for use therein
Assignee: Rolls Royce PLC
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Filing: 1969-05-12
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Granted: 1971-07-20
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Expires: 1989-05-12
Abstract
Abstract A spark-machining electrode comprises an electrode plate which is corrugated in at least a portion thereof, the corrugations being of greater height than the thickness of the plate and having parallel axes such that, in a spark-machining operation, relative approaching movement between the electrode and a workpiece parallel to the axes of the corrugations will produce at least one narrow elongated cavity having a cross-sectional dimension less than the height of the corrugations.
Inventors
- 👤 Irvin Holroyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:35
CPC Classifications
B; B23; B23H; B23H9/00; F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/18; F01D5/186; F05; F05D; F05D2230/00; F05D2230/10; F05D2230/12; F05D2240/00; F05D2240/20; F05D2240/30; F05D2240/303; F05D2250/00; F05D2250/10; F05D2250/18; F05D2250/183; F05D2250/184; F05D2250/70; F05D2250/75
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
123 words
An improved spark-machining method for substantially improving the dimensional accuracy of a spark-machined narrow elongated cavity within a workpiece wherein the flow of cooling dielectric fluid normally induces undesirable vibrations in a spark-machining electrode, said method comprising the steps of: disposing proximate the workpiece an electrode comprising an electrode plate which is corrugated in at least a portion thereof, the corrugations being of greater height than the thickness of the plate and having parallel axes, applying a potential difference between the workpiece and the electrode, and effecting relative approaching movement of the workpiece and the electrode parallel to the axes of the corrugations to spark machine at least one narrow elongated cavity having a crosssectional dimension less than the height of the corrugations.
Claim 2
Dependent Claim
123 words
An improved spark-machining method for substantially improving the dimensional accuracy of a spark-machined narrow elongated cavity within a workpiece wherein the flow of cooling dielectric fluid normally induces undesirable vibrations in a spark-machining electrode, said method comprising the steps of: disposing proximate the workpiece an electrode comprising an electrode plate which is corrugated in at least a portion thereof, the corrugations being of greater height than the thickness of the plate and having parallel axes, applying a potential difference between the workpiece and the electrode, and effecting relative approaching movement of the workpiece and the electrode parallel to the axes of the corrugations to spark machine at least one narrow elongated cavity having a crosssectional dimension less than the height of the corrugations.
Claim 3
Dependent Claim
13 words
A method as claimed in claim 1 wherein the corrugations have straight axes.
Claim 4
Dependent Claim
73 words
A method as claimed in claim 1 wherein the corrugations are arcuately curved and have arcuate axes, the centers of respective arcs defining the corrugations and defining the axes thereof all lying on a common straight line which extends perpendicularly to the arcs, the said relative approaching movement being relative approaching movement of the workpiece and the electrode along an arcuate path, the arc defining the path being centered on the common line.
Claim 5
Dependent Claim
31 words
A method as claimed in claim 1 wherein the corrugations intersect a free edge of the plate, said edge being the leading edge of the plate during said relative approaching movement.
Claim 6
Dependent Claim
45 words
A method as claimed in claim 1 wherein the plate comprises a number of parallel tubes joined together side by side, like portions of the tubes having been removed to provide corrugations which are scallop-shaped in cross section and which extend to the said edge.
Claim 7
Dependent Claim
34 words
A method as claimed in claim 4 wherein the plate when viewed in a cross section intersecting the axes of the corrugations has at least one discontinuity, the discontinuity extending to the said edge.
Claim 8
Dependent Claim
22 words
A method as claimed in claim 6 wherein alternate corrugations have been removed from the plate to form a plurality of discontinuities.
Claim 9
Dependent Claim
44 words
A method as claimed in claim 6 wherein the plate comprises an elongated slot which extends from the said edge longitudinally and transversely of the electrode plate and contains or extends parallel to a surface containing the axes of the corrugations, forming the discontinuity.
Claim 10
Dependent Claim
33 words
A method as claimed in claim 1 wherein the plate has at least one further free edge which extends parallel to the axes of the corrugations and has been bent over upon itself.
Claim 11
Dependent Claim
13 words
A method as claimed in claim 1 wherein the plate is of copper.
Claim 12
Dependent Claim
26 words
A method as claimed in claim 1 comprising directing dielectric fluid towards the electrode and the workpiece for cooling thereof and for the removal of swarf.
Claim 13
Dependent Claim
9 words
An article made by the method of claim 1.
References Cited (Backward Citations)
US2765394A
Cited
US3019178A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |