US3577753A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for forming thin-walled cylindrical articles
Assignee: Bethlehem Steel Corp
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Filing: 1968-09-30
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Granted: 1971-05-04
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Expires: 1988-09-30
Abstract
Abstract A method and apparatus for forming thin-walled containers from flat blanks is disclosed herein. The flat blanks are precoated with a dry film lubricant and drawn and ironed through a series of dies. Apparatus is provided to prevent the thermal breakdown of the lubricant comprising an internally fluid-cooled punch and fluid-cooled dies.
Inventors
- 👤 Dipak C Shah
- 👤 Louis S Schwartz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:36
CPC Classifications
B; B21; B21D; B21D22/00; B21D22/20; B21D22/201; B21D22/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
55 words
A method of drawing and ironing thin-walled cylindrical articles from a flat blank comprising the steps of: a. coating said blank with a dry film lubricant, b. forcing said blank through a series of drawing and ironing dies, and c. maintaining the surface temperature of said blank less than the breakdown temperature of said lubricant.
Claim 2
Independent Claim
55 words
A method of drawing and ironing thin-walled cylindrical articles from a flat blank comprising the steps of: a. coating said blank with a dry film lubricant, b. forcing said blank through a series of drawing and ironing dies, and c. maintaining the surface temperature of said blank less than the breakdown temperature of said lubricant.
Claim 3
Dependent Claim
20 words
The method according to claim 1 wherein the provision of step (c) includes cooling the working surface of said punch.
Claim 4
Dependent Claim
20 words
The method according to claim 2 further including cooling said series of drawing and ironing dies during the die stroke.
Claim 5
Dependent Claim
103 words
In apparatus for multiple stage drawing and ironing of thin-walled cylindrical articles from a flat blank coated with a dry film lubricant, the improvement comprising, in combination: a. an internally fluid-cooled punch, b. a first die and a second die, each of said dies having an aperture, c. spacer means to maintain said first die and said second die in spaced relation, said spacer means having a passage in alignment with said first and second die apertures, and d. means to pass a cooling fluid into said spacer means passage to cool said blank as it is drawn through said spacer means passage.
Claim 6
Dependent Claim
103 words
In apparatus for multiple stage drawing and ironing of thin-walled cylindrical articles from a flat blank coated with a dry film lubricant, the improvement comprising, in combination: a. an internally fluid-cooled punch, b. a first die and a second die, each of said dies having an aperture, c. spacer means to maintain said first die and said second die in spaced relation, said spacer means having a passage in alignment with said first and second die apertures, and d. means to pass a cooling fluid into said spacer means passage to cool said blank as it is drawn through said spacer means passage.
Claim 7
Dependent Claim
31 words
Apparatus according to claim 4 wherein said punch is provided with a plurality of radially spaced longitudinal bores adjacent the surface of said punch adapted to receive a circulating cooling medium.
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) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |