US3817076A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for and method of drawing a cup-shaped article
Assignee: Reynolds Metals Co
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Filing: 1973-05-03
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Granted: 1974-06-18
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Expires: 1993-05-03
Abstract
Abstract An apparatus for and method of drawing a cup-shaped article from a flat sheet blank wherein the apparatus comprises a first die structure having a die cavity therein and having a first drawing surface and a second die structure having a die center adapted to be received within the die cavity and having a pressure pad assembly provided as a part of the second die structure and such assembly comprises a plurality of concentric drawing surfaces which include an outer drawing surface and an inner drawing surface, with the outer and inner drawing surfaces being relatively axially movable. The apparatus has means causing relative movement in an axial direction between the die structures to draw the sheet blank between the first drawing surface and the concentric drawing surfaces and fluid cushion means assures the entire blank may be drawn without pinching and the forming of knife-like edges in its peripheral edge portion.
Inventors
- 👤 J Wallace
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:50
CPC Classifications
B; B21; B21D; B21D22/00; B21D22/20; B21D22/22; B21D24/00; B21D24/04; B21D24/08
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
316 words
An apparatus for drawing a cup-shaped article from a sheet blank comprising; a first die structure having a die cavity therein and having a first drawing surface; a second die structure having a die center adapted to be received within said die cavity; a pressure pad comprising said second die structure; said pressure pad having a plurality of concentric drawing surfaces and including an outer drawing surface and an inner drawing surface; said outer and inner drawing surfaces being relatively axially movable; means causing relative movement in an axial direction between said die structures to draw said sheet blank between said first drawing surface and said concentric drawing surfaces; and fluid cushion means for said pressure pad; said fluid cushion means holding said plurality of concentric drawing surfaces against said blank at the beginning of the drawing action on said blank, allowing relative movement in said axial direction between said inner and outer surfaces once the peripheral edge portion of said blank has moved out of engagement with said outer drawing surface, and controlling said inner drawing surface once the peripheral edge portion of said blank remains to be drawn to prevent pinching and forming of a knife edge in said peripheral edge portion; said pressure pad comprising an outer draw ring having said outer drawing surface defined thereon and an inner draw ring having said inner drawing surface defined thereon; said fluid cushion means comprising a fluid pressure chamber between said draw rings and means for introducing a fluid under pressure into said chamber and removing said fluid therefrom, said means for introducing and removing allowing fluid in said chamber to be expelled therethrough to allow said relative movement between said rings and hence said inner and outer surfaces and once said peripheral edge portion of said blank remains to be drawn serves to delay introduction of fluid in said chamber to prevent said pinching.
Claim 2
Independent Claim
316 words
An apparatus for drawing a cup-shaped article from a sheet blank comprising; a first die structure having a die cavity therein and having a first drawing surface; a second die structure having a die center adapted to be received within said die cavity; a pressure pad comprising said second die structure; said pressure pad having a plurality of concentric drawing surfaces and including an outer drawing surface and an inner drawing surface; said outer and inner drawing surfaces being relatively axially movable; means causing relative movement in an axial direction between said die structures to draw said sheet blank between said first drawing surface and said concentric drawing surfaces; and fluid cushion means for said pressure pad; said fluid cushion means holding said plurality of concentric drawing surfaces against said blank at the beginning of the drawing action on said blank, allowing relative movement in said axial direction between said inner and outer surfaces once the peripheral edge portion of said blank has moved out of engagement with said outer drawing surface, and controlling said inner drawing surface once the peripheral edge portion of said blank remains to be drawn to prevent pinching and forming of a knife edge in said peripheral edge portion; said pressure pad comprising an outer draw ring having said outer drawing surface defined thereon and an inner draw ring having said inner drawing surface defined thereon; said fluid cushion means comprising a fluid pressure chamber between said draw rings and means for introducing a fluid under pressure into said chamber and removing said fluid therefrom, said means for introducing and removing allowing fluid in said chamber to be expelled therethrough to allow said relative movement between said rings and hence said inner and outer surfaces and once said peripheral edge portion of said blank remains to be drawn serves to delay introduction of fluid in said chamber to prevent said pinching.
Claim 3
Dependent Claim
21 words
An apparatus as set forth in claim 1 in which said means for introducing and removing said fluid comprises orifice means.
Claim 4
Dependent Claim
44 words
An apparatus as set forth in claim 2 in which said outer draw ring comprises a substantially L-shaped ring having a vertical leg portion and a horizontal leg portion and said outer drawing surface comprises a top horizontal surface of said vertical leg portion.
Claim 5
Dependent Claim
59 words
An apparatus as set forth in claiM 3 in which said horizontal leg portion of said outer draw ring has a substantially horizontally extending surface and said inner draw ring is supported concentrically within said vertical leg portion and has a bottom surface which is adapted to be supported on said horizontally extending surface of said horizontal leg portion.
Claim 6
Dependent Claim
20 words
An apparatus as set forth in claim 4 and further comprising seal means between said rings defining said pressure chamber.
Claim 7
Dependent Claim
39 words
An apparatus as set forth in claim 5 in which said means for introducing and removing said fluid comprises an orifice extending through said horizontal leg portion of said outer draw ring and communicating with said fluid under pressure.
Claim 8
Dependent Claim
60 words
An apparatus as set forth in claim 6 in which said fluid cushion means further comprises a fluid operated cylinder supporting said outer draw ring and hence both of said draw rings, said fluid operated cylinder having passage means therein, said passage means having one end communicating with said fluid under pressure and its opposite end communicating with said orifice.
Claim 9
Dependent Claim
44 words
An apparatus as set forth in claim 1 and further comprising a support supporting said second die structure at a fixed position and said means causing relative movement comprises means for moving said first die structure toward and away from said second die structure.
Claim 10
Dependent Claim
28 words
An apparatus as set forth in claim 8 in which said means for moving said first die structure is in the form of the ram of a press.
Claim 11
Independent Claim
314 words
A method of drawing a cup-shaped article comprising the steps of; placing a sheet blank between a first die structure having a die cavity therein and having a first drawing surface and a second die structure having a die center adapted to be received within said cavity; said second die structure comprising a pressure pad which has an outer draw ring provided with an outer drawing surface and an inner draw ring provided with an inner drawing surface with said outer and inner rings and their drawing surfaces being relatively axially movable; relatively moving said die structures in an axial direction to draw said sheet blank between said drawing surfaces; supporting said pressure pad with fluid cushion means during said step of relatively moving; said fluid cushion means holding said inner and outer drawing surfaces against said blank at the beginning of the drawing action on said blank, allowing relative movement in said axial direction between said inner and outer surfaces once the peripheral edge portion of said blank has moved out of engagement with said outer drawing surface, and controlling said inner drawing surface once the peripheral edge portion of said blank remains to be drawn to prevent pinching and forming of a knife edge in said peripheral edge portion; said step of supporting said pressure pad with fluid cushion means comprising providing a fluid pressure chamber between said draw rings and introducing a fluid under pressure into said pressure chamber and removing said fluid therefrom through associated means, said associated means allowing fluid in said pressure chamber to be expelled therethrough to allow said relative movement between said rings and hence said inner and outer surfaces at the beginning of the drawing of said blank and once said peripheral edge portion of said blank remains to be drawn serves to delay introduction of fluid in said pressure chamber to prevent said pinching.
Claim 12
Independent Claim
314 words
A method of drawing a cup-shaped article comprising the steps of; placing a sheet blank between a first die structure having a die cavity therein and having a first drawing surface and a second die structure having a die center adapted to be received within said cavity; said second die structure comprising a pressure pad which has an outer draw ring provided with an outer drawing surface and an inner draw ring provided with an inner drawing surface with said outer and inner rings and their drawing surfaces being relatively axially movable; relatively moving said die structures in an axial direction to draw said sheet blank between said drawing surfaces; supporting said pressure pad with fluid cushion means during said step of relatively moving; said fluid cushion means holding said inner and outer drawing surfaces against said blank at the beginning of the drawing action on said blank, allowing relative movement in said axial direction between said inner and outer surfaces once the peripheral edge portion of said blank has moved out of engagement with said outer drawing surface, and controlling said inner drawing surface once the peripheral edge portion of said blank remains to be drawn to prevent pinching and forming of a knife edge in said peripheral edge portion; said step of supporting said pressure pad with fluid cushion means comprising providing a fluid pressure chamber between said draw rings and introducing a fluid under pressure into said pressure chamber and removing said fluid therefrom through associated means, said associated means allowing fluid in said pressure chamber to be expelled therethrough to allow said relative movement between said rings and hence said inner and outer surfaces at the beginning of the drawing of said blank and once said peripheral edge portion of said blank remains to be drawn serves to delay introduction of fluid in said pressure chamber to prevent said pinching.
Claim 13
Dependent Claim
23 words
A method as set forth in claim 10 in which said placing step comprises placing a circular sheet blank between said die structures.
Claim 14
Dependent Claim
57 words
A method as set forth in claim 10 in which said supporting step comprises supporting said draw rings with said fluid cushion means including a fluid operated cylinder which supports said outer draw ring and hence both of said draw rings and with means providing said fluid under pressure so that it operatively associates with said cylinder.
Claim 15
Dependent Claim
35 words
A method as set forth in claim 10 in which said second die structure is supported at a fixed position and said relaTively moving step comprises moving said first die structure with associated actuating means.
Claim 16
Dependent Claim
33 words
A method as set forth in claim 13 in which said step of moving said first die structure with actuating means comprises moving said first die structure with the ram of a press.
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) | 1977-06-17 | 1977-12-17 | 1978-06-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-17 | 1981-12-17 | 1982-06-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-17 | 1985-12-17 | 1986-06-18 | $7700.00 | Window Closed / Lapsed |