US3789094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing a molded foamed structural member having a honeycomb core adapted for venting
Assignee: Monostruct Corp Ltd
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Filing: 1971-05-06
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Granted: 1974-01-29
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Expires: 1991-05-06
Abstract
Abstract A cored, molded structural member comprises a core having a plurality of cells between major faces - a honeycomb core - and having a substantially seamless covering of moldable plastic material which expands while it sets and which, when set, is substantially rigid. Foamable polyurethane is particularly contemplated. At least some of the cells of the core are adapted to have gas communication with other, adjacent cells when the pressure of the gas and/or air within the cell rises. The molded structural member is formed in a mold which is entirely closed and gas tight so as to preclude flow of gas or air outwardly from the mold cavity during the molding operation. Spacers may be used to space the core away from the faces of the mold cavity, and to keep the core from shifting within the mold cavity as the plastic material expands and sets. Pressure relief of the pressurized mold is usually provided before the mold is opened, by making one or more channels through the plastic covering in the core.
Inventors
- 👤 D Hutchison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:32
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B29C44/1266; Y; Y10; Y10S; Y10S425/00; Y10S425/812; Y10T; Y10T428/00; Y10T428/23; Y10T428/234; Y10T428/236; Y10T428/24; Y10T428/24149
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
221 words
A method of producing a molded structural member having a core and a substantially seamless covering over said core; where said core has spaced apart first and second major faces and a plurality of walls extending between them to define a plurality of cells between said major faces, and where said first and second major faces and plurality of walls extending there between have openings which communicate with the interior of the cells, comprising the steps of: a Placing a core in a cavity in a mold so that the core is supported away from the faces of said mold cavity; b introducing a foamable thermosetting synthetic plastic material which expands while it is setting into said mold cavity and which, when set, will form a substantially rigid, into encasement of said core; c closing said mold to be substantially gas-tight so that gas flow from within said mold to the exterior thereof is substantially precluded and so that gas entrained in said mold and formed during the expanding of said formable thermosetting synthetic plastic material, is driven into said core; d allowing sufficient time to pass for said plastic material to set at least sufficiently so as to permit unmolding of said molded structural member; and e opening said mold and unmolding said molded structural member from said mold cavity.
Claim 2
Independent Claim
221 words
A method of producing a molded structural member having a core and a substantially seamless covering over said core; where said core has spaced apart first and second major faces and a plurality of walls extending between them to define a plurality of cells between said major faces, and where said first and second major faces and plurality of walls extending there between have openings which communicate with the interior of the cells, comprising the steps of: a Placing a core in a cavity in a mold so that the core is supported away from the faces of said mold cavity; b introducing a foamable thermosetting synthetic plastic material which expands while it is setting into said mold cavity and which, when set, will form a substantially rigid, into encasement of said core; c closing said mold to be substantially gas-tight so that gas flow from within said mold to the exterior thereof is substantially precluded and so that gas entrained in said mold and formed during the expanding of said formable thermosetting synthetic plastic material, is driven into said core; d allowing sufficient time to pass for said plastic material to set at least sufficiently so as to permit unmolding of said molded structural member; and e opening said mold and unmolding said molded structural member from said mold cavity.
Claim 3
Dependent Claim
28 words
The method of claim 1 where said step (c) is carried out between steps (a) and (b) and said foamable thermosetting synthetic plastic is a foamable polyurethane resin.
Claim 4
Dependent Claim
60 words
The method of claim 1 where said mold is made substantially gas-tight by gasket material placed between the parts of said mold which close around said mold cavity; so that, when said mold is open, the steps of placing at least said core into said mold cavity and the unmolding of the molded structural member therefrom can be carried out.
Claim 5
Dependent Claim
73 words
The method of claim 1, further comprising the step of: f after step (d) and before step (e), making at least one passage through a face of said mold and through said plastic material and at least one of said major faces of said core, and extending into at least one of said cells of said core so as to provide gas communication from said at least one cell to the surrounding atmosphere.
Claim 6
Dependent Claim
34 words
The method of claim 4, further comprising the step of: g placing compression means over said mold to reinforce the mold against internal pressures developed within it as said moldable plastic material is setting.
Claim 7
Dependent Claim
132 words
The method of claim 4, further comprising the step of: h at least before step (b), placing a plurality of spacers on at least one of said major faces of said core, each of which has a first and a second leg substantially coaxial with one another on either side of a substantially flat, planar land projecting radially outwardly from said first and second legs; the lengths of said first and second legs, respectively, being each greater than the thickness of the land; so that said second leg of each of said plurality of spacers pierces through the one of said major faces of said core on which it is placed so that the land of each said spacer is on the outer side of the respective one of said major faces.
Claim 8
Dependent Claim
61 words
The method of claim 6, further comprising the step of: i at least before step (b), providing opening to a plurality of cells of said core through one of said major faces, so as to provide communication thereinto of said moldable plastic material, and so that at least some of said open cells are adjacent to others of said open cells.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |