Patent US3869233A successfully refreshed from Google Patents.
US3869233A
Expired / Lapsed
US
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Apparatus for rapid isostatic pressing
Assignee: National Forge Co
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Filing: 1974-05-28
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Granted: 1975-03-04
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Expires: 1994-05-28
Abstract
Abstract Apparatus for compacting preheated powder bodies in a high pressure isostatic pressure vessel in which a liquid such as water is used as the pressurizing medium. A preheated workpiece is inserted into the vessel which is closed and sealed. The vessel is then rapidly filled with the liquid pressurizing medium while avoiding contact of the medium with the preheated workpiece until the vessel is substantially completely full. The pressure within the vessel is then increased rapidly to a preselected compacting level by continually pumping the liquid pressurizing medium into the vessel. The preselected compacting pressure is in excess of the critical pressure of the liquid pressurizing medium. The rapid increase of pressure within the vessel to a level exceeding the critical pressure minimizes the amount of vapor that is formed in the vessel and reduces heat transfer from the preheated body to the pressurizing system. In a preferred embodiment, avoidance of contact of the pressurizing medium with the preheated workpiece until the vessel is substantially completely filled is accomplished by the use of a shielding container. Alternative means are disclosed. Means for increasing the temperature of the workpiece after it is inserted into the pressure vessel are disclosed. Means for rapidly reducing the pressure within the vessel and for withdrawing the pressurizing medium are also disclosed.
Inventors
- 👤 Donald E Witkin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:20
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/14; B22F3/15; B22F3/02; B22F3/04; B30; B30B; B30B11/00; B30B11/001
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
94 words
Apparatus for compacting a preheated porous body by isostatically hot pressing the same comprising a pressure vessel, means for rapidly filling said pressure vessel with a liquid pressurizing medium and for rapidly increasing the pressure of said medium within said pressure vessel to a preselected compacting pressure, means for releasing the pressure within said pressure vessel at said preselected pressure, means for emptying said pressurizing medium from said pressure vessel, and means for avoiding contact of said pressurizing medium with said body until said pressure vessel is substantially completely filled with said pressurizing medium.
Claim 2
Dependent Claim
94 words
Apparatus for compacting a preheated porous body by isostatically hot pressing the same comprising a pressure vessel, means for rapidly filling said pressure vessel with a liquid pressurizing medium and for rapidly increasing the pressure of said medium within said pressure vessel to a preselected compacting pressure, means for releasing the pressure within said pressure vessel at said preselected pressure, means for emptying said pressurizing medium from said pressure vessel, and means for avoiding contact of said pressurizing medium with said body until said pressure vessel is substantially completely filled with said pressurizing medium.
Claim 3
Dependent Claim
15 words
The apparatus of claim 1 wherein the pressure vessel is a cold, dry pressure vessel.
Claim 4
Dependent Claim
15 words
The apparatus of claim 1 wherein said filling and pressure increasing means comprises a pump.
Claim 5
Dependent Claim
20 words
The apparatus of claim 3 wherein the pressure releasing means comprises a rupture disc assembly having a pre-selected burst pressure.
Claim 6
Dependent Claim
112 words
The apparatus of claim 3 wherein said contact avoiding means comprises a shielding container surrounding said body and spaced from both the internal wall of said pressure vessel and the external surface of said body to provide a first space within said pressure vessel between said pressure vessel and said container and a second space within said pressure vessel between said container and said body, said container having a side wall and an open top, said side wall extending above said body whereby when said liquid pressurizing medium is introduced into said first space it will substantially fill the same before entering said second space and coming in contact with said body.
Claim 7
Dependent Claim
24 words
The apparatus of claim 5 wherein the volume of said first space is at least about 10 times the volume of said second space.
Claim 8
Dependent Claim
17 words
The apparatus of claim 1 further comprising means within said vessel for supplying heat to said body.
Claim 9
Dependent Claim
15 words
The apparatus of claim 7 in which the heat supplying means is a heat sink.
Claim 10
Dependent Claim
84 words
The apparatus of claim 3 in which said contact avoiding means comprises a cylindrical inner wall within said pressure vessel, a cylindrical liquid deflector within said pressure vessel forming an annular space with said wall, a liquid inlet arranged to deliver said liquid pressurizing medium into said space tangentially to said wall at high velocity and wherein said deflector is disposed in the path of said pressurizing medium to cause the latter to form a liquid vortex within said vessel while filling the same.
Claim 11
Dependent Claim
100 words
The apparatus of claim 3 in which said contact avoiding means comprises a pressure vessel having an axis of symmetry, means to rotate said pressure vessel about said axis, a cylindrical inner wall within said pressure vessel, a cylindrical liquid deflector within said pressure vessel forming an annular space with said wall, and a liquid inlet arranged with said deflector to deliver said liquid pressurizing medium into said space whereby when liquid is introduced into said vessel while rotating the same centrifugal forces imposed upon said liquid will cause the same to form a layer of liquid against said wall.
Claim 12
Dependent Claim
258 words
Apparatus for compacting a preheated porous body by isostatically hot pressing the same comprising a pressure vessel the internal wall of which is cylindrical, means for rapidly filling said pressure vessel with a liquid pressurizing medium and for rapidly increasing the pressure of said medium within said pressure vessel to a preselected compacting temperature, means for releasing the pressure within said pressure vessel at said preselected pressure, means for emptying said pressurizing medium from said pressure vessel, and means for avoiding contact of said pressurizing medium with said body until said pressure vessel is substantially completely filled with said pressurizing fluid, said last mentioned means comprising a shielding container having a cylindrical wall, a liquid tight bottom and an open top, said container surrounding said body and being spaced both from the internal wall of said pressure vessel and from the external surface of said body to provide a first annular space within said pressure vessel between said pressure vessel and said container and a second space within said pressure vessel between said container and said body, said body being supported within said container by said liquid tight bottom, the bottom of said container being spaced from the bottom of said pressure vessel by supporting means thereby reducing the transfer of heat from said body to said pressure vessel, and said cylindrical wall of said container extending above said body whereby when liquid is introduced into said first annular space it Will substantially fill the same before entering said second space and coming in contact with said body.
Claim 13
Dependent Claim
258 words
Apparatus for compacting a preheated porous body by isostatically hot pressing the same comprising a pressure vessel the internal wall of which is cylindrical, means for rapidly filling said pressure vessel with a liquid pressurizing medium and for rapidly increasing the pressure of said medium within said pressure vessel to a preselected compacting temperature, means for releasing the pressure within said pressure vessel at said preselected pressure, means for emptying said pressurizing medium from said pressure vessel, and means for avoiding contact of said pressurizing medium with said body until said pressure vessel is substantially completely filled with said pressurizing fluid, said last mentioned means comprising a shielding container having a cylindrical wall, a liquid tight bottom and an open top, said container surrounding said body and being spaced both from the internal wall of said pressure vessel and from the external surface of said body to provide a first annular space within said pressure vessel between said pressure vessel and said container and a second space within said pressure vessel between said container and said body, said body being supported within said container by said liquid tight bottom, the bottom of said container being spaced from the bottom of said pressure vessel by supporting means thereby reducing the transfer of heat from said body to said pressure vessel, and said cylindrical wall of said container extending above said body whereby when liquid is introduced into said first annular space it Will substantially fill the same before entering said second space and coming in contact with said body.
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) | 1978-03-03 | 1978-09-02 | 1979-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-03 | 1982-09-02 | 1983-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-03 | 1986-09-02 | 1987-03-04 | $7700.00 | Window Closed / Lapsed |