Patent US3769824A successfully refreshed from Google Patents.
US3769824A
Expired / Lapsed
US
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Deep drawing method
Assignee: Armco Inc
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Filing: 1972-06-14
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Granted: 1973-11-06
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Expires: 1992-06-14
Abstract
Abstract Method for deep drawing metallic articles from sheet material utilizing a die plate having a female cavity, a holddown member for holding sheet material against the die plate around the cavity, and a male die punch for drawing the sheet material into the female cavity. Prior to placing the sheet material over the female cavity, the cavity is substantially filled with a liquid lubricant. The hold-down acts to hold the sheet material against the die plate so as to prevent wrinkling during drawing in a conventional manner, and the male die draws the sheet material into the liquid filled cavity forcing the liquid lubricant between the under surface of the sheet material and the die plate.
Inventors
- 👤 W Granzow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:02
CPC Classifications
B; B21; B21D; B21D22/00; B21D22/20; B21D22/205; B21D22/22; B21D37/00; B21D37/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
139 words
In a method of deep drawing metallic articles from sheet material including the steps of providing a die having a top surface and a female cavity terminating at said top surface in a die radius, placing a sheet of material over said cavity, holding said sheet of material agAinst said die top surface whereby to restrict wrinkling of said sheet during drawing, and drawing said sheet of material into said cavity with a male die punch: the improvement comprising the steps of substantially filling said cavity with a liquid lubricant prior to drawing and continuously forcing liquid lubricant out of said cavity during drawing, all liquid lubricant forced out of said cavity being forced between said material being drawn and said die radius and die top surface in a direction opposite to the flow of said material being drawn.
Claim 2
Dependent Claim
139 words
In a method of deep drawing metallic articles from sheet material including the steps of providing a die having a top surface and a female cavity terminating at said top surface in a die radius, placing a sheet of material over said cavity, holding said sheet of material agAinst said die top surface whereby to restrict wrinkling of said sheet during drawing, and drawing said sheet of material into said cavity with a male die punch: the improvement comprising the steps of substantially filling said cavity with a liquid lubricant prior to drawing and continuously forcing liquid lubricant out of said cavity during drawing, all liquid lubricant forced out of said cavity being forced between said material being drawn and said die radius and die top surface in a direction opposite to the flow of said material being drawn.
Claim 3
Dependent Claim
28 words
The method claimed in claim 1 wherein said liquid lubricant is forced out of said cavity by the entrance therein of said punch and said material being drawn.
Claim 4
Dependent Claim
12 words
The method claimed in claim 1 wherein said liquid lubricant is water.
Claim 5
Dependent Claim
12 words
The method claimed in claim 2 wherein said liquid lubricant is water.
Claim 6
Dependent Claim
17 words
The method claimed in claim 4 wherein said water contains a small quantity of water soluble lubricant.
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) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |