US3704081A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vacuum mold for making foamed polymeric articles
Assignee: Atlantic Richfield Co
•
Filing: 1971-01-21
•
Granted: 1972-11-28
•
Expires: 1991-01-21
Abstract
Abstract A mold for the vacuum molding of foamed cellular thermoplastic articles has two cooperating sections which when placed together define a mold cavity. Each section has three shells and two standard chests including an inner shell, an intermediate shell and an outer shell. The intermediate shell is spaced apart from the inner shell to define a first chest and the outer shell is spaced apart from the intermediate shell to define a second chest. The first chest has inlet and outlet means which are connected to a source of heating and cooling media and the second chest has inlet and outlet means which are connected to atmospheric air, compressed air and vacuum lines. A plurality of venting means communicate between the mold cavity and the second chest whereby a vacuum may be drawn or air may be charged into the mold cavity. At least one section has inlet means for passing expanded or partially expanded granules of a thermoplastic material into the mold cavity after the sections are brought together and a means for opening and closing the mold sections by moving one of the sections relative to the other.
Inventors
- 👤 Richard H Immel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:30
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/3403; B29C44/36; B29C44/38; B29C44/44; B29C44/445; B29C33/00; B29C33/02; B29C33/04; B29C33/10; Y; Y10; Y10S; Y10S425/00; Y10S425/812
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
277 words
A mold for use in vacuum molding of shaped, foamed, cellular thermoplastic articles from expandable thermoplastic material, comprising: a. two cooperating mold sections that are capable of forming an airtight cavity when both sections are brought together; each section comprising: i. a solid inner shell shaped to define one part of the mold cavity; said inner shell having lands capable of forming an airtight seal when said sections are brought together; ii. a solid intermediate shell releasably connected with fasteners in a coextensive spaced apart relationship to said inner shell to define a first chest; said intermediate shell having lands engaging said inner shell which lands are capable of forming an airtight seal with said inner shell; iii. a solid outer shell releasably connected with fasteners in a spaced apart relationship to said intermediate shell to define a second chest; said outer shell having lands engaging said intermediate shell which lands are capable of forming an airtight seal with said intermediate shell; iv. a plurality of venting means extending between said mold cavity and said second chest for providing an airtight passageway therebetween such that said shells are releasable from each other; v. inlet and outlet means connecting said second chest to vacuum and air sources; vi. inlet and outlet means connecting said first chest to cooling and heating media for circulation of said media through said first chest; and b. at least one section having inlet means for introducing said expandable material into said mold cavity when said sections are brought together; and c. at least one section having means for opening and closing said mold by moving one of said sections relative to the other.
Claim 2
Dependent Claim
277 words
A mold for use in vacuum molding of shaped, foamed, cellular thermoplastic articles from expandable thermoplastic material, comprising: a. two cooperating mold sections that are capable of forming an airtight cavity when both sections are brought together; each section comprising: i. a solid inner shell shaped to define one part of the mold cavity; said inner shell having lands capable of forming an airtight seal when said sections are brought together; ii. a solid intermediate shell releasably connected with fasteners in a coextensive spaced apart relationship to said inner shell to define a first chest; said intermediate shell having lands engaging said inner shell which lands are capable of forming an airtight seal with said inner shell; iii. a solid outer shell releasably connected with fasteners in a spaced apart relationship to said intermediate shell to define a second chest; said outer shell having lands engaging said intermediate shell which lands are capable of forming an airtight seal with said intermediate shell; iv. a plurality of venting means extending between said mold cavity and said second chest for providing an airtight passageway therebetween such that said shells are releasable from each other; v. inlet and outlet means connecting said second chest to vacuum and air sources; vi. inlet and outlet means connecting said first chest to cooling and heating media for circulation of said media through said first chest; and b. at least one section having inlet means for introducing said expandable material into said mold cavity when said sections are brought together; and c. at least one section having means for opening and closing said mold by moving one of said sections relative to the other.
Claim 3
Dependent Claim
43 words
The mold of claim 1 wherein each of said venting means comprises a hollow bolt that passes through said outer and intermediate shell and that is threaded into said inner shell for providing a passageway from said mold cavity to said second chest.
Claim 4
Dependent Claim
41 words
The mold of claim 1 wherein each of said venting means comprises a hollow bolt that passes through said inner shell and that is threaded into said intermediate shell for providing a passageway from said mold cavity to said second chest.
Claim 5
Dependent Claim
98 words
The mold of claim 2 wherein said bolt comprises: a. a shank having an externally threaded portion at one end thereof; b. a radially extending head at the other end of said shank; c. an axial first bore in said threaded portion extending from the terminal end thereof toward said head; and d. a second bore, disposed normal to said first bore, passing through said shank and intersecting said first bore, thereby providing a bifurcated passageway in said bolt; and e. said bolt being so positioned in said mold that said second bore communicates with said second chest.
Claim 6
Dependent Claim
34 words
The mold of claim 4 wherein: a. said bolt has a groove in said shank; and b. a sealing gasket in said groove that provides a seal between said bolt and said outer shell.
Claim 7
Dependent Claim
67 words
The mold of claim 3 wherein said hollow bolt comprises: a. an externally threaded shank; b. a tip at one end of said shank; c. a radially extending head at the other end of said shank; and d. an axial bore completely passing through said shank starting at the tip and terminating at the head for providing a passageway from Said mold cavity to said second chest.
Claim 8
Dependent Claim
93 words
The mold of claim 1 wherein each of said venting means comprises: a. apertures in said inner and intermediate shells that are coaxially aligned; b. a boss having an internally threaded bore extending between said inner and intermediate shells; with said bore being coaxially aligned with said apertures; one end of said boss being fixed to said inner shell; and c. a hollow bolt being threaded into said boss for providing the passageway from said mold cavity to said second chest and for forcing said intermediate shell into airtight engagement with said boss.
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) | 1975-11-28 | 1976-05-29 | 1976-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-28 | 1980-05-29 | 1980-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-28 | 1984-05-29 | 1984-11-28 | $7700.00 | Window Closed / Lapsed |