US3879161A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for centrifugal casting
Assignee: Bridgestone Firestone Inc
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Filing: 1973-01-26
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Granted: 1975-04-22
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Expires: 1993-01-26
Abstract
Abstract The process of centrifugally casting an article such as a tire or the like from a curable or hardenable liquid polymeric material, which process includes the steps of selecting a mold and placing a core within the mold which core is hollow and/or is readily deformable under pressure but which has sufficient memory to resume its original position when the pressure is removed. The article being formed is formed between the core and the mold. The space between the core and the mold is filled with the curable liquid material of which the article is to be formed and the hollow core is also filled with a liquid material. The liquid material in the hollow core, the material from which the core is constructed and the curable liquid material all have about the same specific gravity. The mold and core are rotated to centrifugally cast the article which is formed of the curable liquid material. The deformable core permits easy removal from the completed article and the matching of the specific gravities as aforementioned keeps the deformable core from distorting during the centrifugal casting operation. The order of introducing the liquid material into the core, introducing the curable liquid into the space between the mold and core and rotation of the mold and core can be varied within the limits as set forth in the following description. Variations in the structure for accomplishing the principle of matching specific gravities are illustrated and described.
Inventors
- 👤 Daniel Ross Mcgillvary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:56
CPC Classifications
B; B29; B29D; B29D30/00; B29D30/06; B29D30/0679; B29C; B29C33/00; B29C33/44; B29C33/48; B29C33/50; B29C33/505; B29C39/00; B29C39/02; B29C39/04; B29C39/08; B29L; B29L2030/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
95 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, a hollow flexible core mounted within said mold which core is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the space between the core and mold which material is to form the finished article, a stabilizing liquid material in said hollow core, said material of construction of said core, said curable liquid material and said stabilizing liquid material all having substantially the same specific gravity.
Claim 2
Dependent Claim
95 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, a hollow flexible core mounted within said mold which core is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the space between the core and mold which material is to form the finished article, a stabilizing liquid material in said hollow core, said material of construction of said core, said curable liquid material and said stabilizing liquid material all having substantially the same specific gravity.
Claim 3
Dependent Claim
95 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, a hollow flexible core mounted within said mold which core is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the space between the core and mold which material is to form the finished article, a stabilizing liquid material in said hollow core, said material of construction of said core, said curable liquid material and said stabilizing liquid material all having substantially the same specific gravity.
Claim 4
Dependent Claim
95 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, a hollow flexible core mounted within said mold which core is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the space between the core and mold which material is to form the finished article, a stabilizing liquid material in said hollow core, said material of construction of said core, said curable liquid material and said stabilizing liquid material all having substantially the same specific gravity.
Claim 5
Dependent Claim
23 words
Apparatus as claimed in claim 1, wherein the article is a vehicle tire and the mold is constructed of a relatively rigid material.
Claim 6
Dependent Claim
13 words
Apparatus as claimed in claim 2, wherein the relatively rigid material is metal.
Claim 7
Dependent Claim
41 words
Apparatus as claimed in claim 1, wherein the article is a vehicle tire and the mold is mounted for rotation by a substantially horizontally disposed shaft, means are provided for introducing and removing the stabilizing liquid material from the hollow core.
Claim 8
Dependent Claim
24 words
Apparatus as claimed in claim 4, wherein means are provided for heating the stabilizing liquid material prior to being introduced into the hollow core.
Claim 9
Dependent Claim
83 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, a solid and flexible core mounted within said mold which core is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the space between the core and mold which material is to form the finished article, said material of construction of said core and said curable liquid material having substantially the same specific gravity.
Claim 10
Dependent Claim
83 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, a solid and flexible core mounted within said mold which core is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the space between the core and mold which material is to form the finished article, said material of construction of said core and said curable liquid material having substantially the same specific gravity.
Claim 11
Dependent Claim
23 words
Apparatus as claimed in claim 6, wherein the article is a vehicle tire and the mold is constructed of a relatively rigid material.
Claim 12
Dependent Claim
13 words
Apparatus as claimed in claim 6, wherein the relatively rigid material is metal.
Claim 13
Dependent Claim
26 words
Apparatus as claimed in claim 6, wherein the article is a vehicle tire and the mold is mounted for rotation by a substantially horizontally disposed shaft.
Claim 14
Dependent Claim
72 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, said mold being solid and is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the mold which material is to form the finished article, said material of construction of said mold and said curable liquid material having substantially the same specific gravity.
Claim 15
Dependent Claim
72 words
Apparatus for centrifugally casting an article including in combination a mold, means for rotating said mold, said mold being solid and is deformable under pressure but has sufficient memory to resume its original position when the pressure is removed, a curable liquid material in the mold which material is to form the finished article, said material of construction of said mold and said curable liquid material having substantially the same specific gravity.
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) | 1978-04-21 | 1978-10-21 | 1979-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-21 | 1982-10-21 | 1983-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-21 | 1986-10-21 | 1987-04-22 | $7700.00 | Window Closed / Lapsed |