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US3962393A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for making a hollow laminated article

Assignee: Lockheed Martin Corp
•
Filing: 1974-05-07
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Granted: 1976-06-08
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Expires: 1994-05-07
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Abstract

Abstract A method is disclosed for fabricating in a single stage hollow polymeric article of manufacture from a flexible fibrous material, regardless of the degree of complexity of the laminate. The material is applied to a hollow flexible envelope which includes a pattern of any degree of complexity and which is supported on a solid mandrel, to be encased in a two-part female die. The envelope and applied material are sealed off from the mandrel by means of film layers forming a bag. A vacuum is established within the bag, resulting in forces acting from the inner side of the envelope through it and the laminated material against the die walls. The support mandrel is removed, and the remaining assembly is cured under the vacuum with or without elevated pressures. After cooling, the die and envelope are readily removed from the article. The apparatus comprises the envelope, the support mandrel, impermeable sealing film for bagging the laminate, the tooling such as a female die or caul plates, means for establishing a vacuum on the bagged laminate and tooling, and optionally, means for turning the envelope and mandrel as the material is applied to the envelope pattern.

Inventors

  • 👤 Leiv H. Blad

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 00:41
CPC Classifications
B; B29; B29D; B29D28/00; B29D28/005; B29C; B29C33/00; B29C33/44; B29C33/48; B29C33/485; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/42; B29C70/44; B29C70/446; B29D22/00; B29C43/00; B29C43/02; B29C43/10; B29C43/12; B29K; B29K2105/00; B29K2105/06

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 122 words
The method of making a fiber-reinforced polymeric hollow article comprising: forming a flexible mold envelope having a pattern of channels in an external surface thereof; supporting said envelope on a solid mandrel disposed internally thereof; applying a curable resin and flexible fibrous material about said supported envelope and in the channels thereof; enclosing an assembly of said envelope and said mandrel with applied said resin and fibrous material within a rigid die; sealably enclosing said envelope and said rigid die to form a sealed enclosure; establishing a vacuum in said sealed enclosure while admitting at least atmospheric pressure internally of said envelope in such a way as to form a separation between said envelope and said rigid die; and curing said resin.
Claim 2
Independent Claim 122 words
The method of making a fiber-reinforced polymeric hollow article comprising: forming a flexible mold envelope having a pattern of channels in an external surface thereof; supporting said envelope on a solid mandrel disposed internally thereof; applying a curable resin and flexible fibrous material about said supported envelope and in the channels thereof; enclosing an assembly of said envelope and said mandrel with applied said resin and fibrous material within a rigid die; sealably enclosing said envelope and said rigid die to form a sealed enclosure; establishing a vacuum in said sealed enclosure while admitting at least atmospheric pressure internally of said envelope in such a way as to form a separation between said envelope and said rigid die; and curing said resin.
Claim 3
Dependent Claim 15 words
The method of claim 1 wherein the flexible mold envelope comprises a hollow rubber mold.
Claim 4
Dependent Claim 14 words
The method of claim 1 wherein the flexible mold envelope comprises a collapsible mandrel.
Claim 5
Dependent Claim 30 words
The method of claim 1 wherein the first-mentioned enclosing step comprises transferring the assembly of said mandrel, envelope, and applied material together to a female die having opposing ends open.
Claim 6
Dependent Claim 13 words
The method of claim 1 including the step of heating said enclosed assembly.
Claim 7
Dependent Claim 15 words
The method of claim 1 including the steps of heating and pressurizing said sealed assembly.
Claim 8
Dependent Claim 29 words
The method of claim 1 including the step of removing the solid mandrel after the step of establishing a vacuum in the sealed enclosure and before heating and pressurizing.
Claim 9
Dependent Claim 40 words
The method of claim 1 wherein said sealing step comprises wrapping the solid mandrel with at least one impermeable film sheet and wrapping a second impermeable film sheet around the rigid die and sealing them together at their opposite ends.
Claim 10
Dependent Claim 43 words
The method of claim 1 wherein said sealing step comprises wrapping the solid mandrel with at least one impermeable film sheet and attaching said sheet to an inside surface of the rigid die after the assembly of applied material, envelope and solid mandrel.
Claim 11
Dependent Claim 25 words
The method of claim 1 wherein the flexible fibrous material utilized therein is selected from the classes of graphite, boron, rayon, cotton, and fiberglass fibers.
Claim 12
Dependent Claim 16 words
The method of claim 10 wherein the flexible fibrous material is in the form of filaments.

References Cited (Backward Citations)

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US2838435A Cited
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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) 1979-06-08 1979-12-08 1980-06-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-06-08 1983-12-08 1984-06-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-06-08 1987-12-08 1988-06-08 $7700.00 Window Closed / Lapsed

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