US5676894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Panel framing system with panel tensioning by heat shrinking
Assignee: Tensar Corp LLC
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Filing: 1996-01-31
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Granted: 1997-10-14
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Expires: 2016-01-31
Abstract
Abstract A simple and inexpensive method and apparatus for molding a peripheral frame around a sheet or grid of thermoplastic material to produce a framed panel. A peripheral frame, preferably of structural foam or the like, is injection molded about a thermoplastic sheet or grid of panel-forming material which has been previously drawn or stretched at a temperature which orients the molecules of the polymer, i.e., below the glass transition temperature of the polymer, T g . Either during the frame molding process, or subsequent thereto, the panel-forming material is heated sufficiently to cause the material to shrink or revert toward its prestretched condition so as to tension the panel-forming material within the frame. Elastomeric sealing means are disclosed for sealing the mold during injection of the frame-forming material and locator fingers are provided to position a grid-like panel-forming material prior to initiation of the molding process. By the utilization of structural foam molding techniques, a panel of thermoplastic material may be integrally-molded and tensioned within a rigid frame to produce a framed panel of any size for use as a barrier, a fence, a guard, a closure, a seat or bedding support, a filter member or other such applications.
Inventors
- 👤 Paul Specht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:50
CPC Classifications
B; B29; B29C; B29C70/00; B29C70/68; B29C70/688; B29C45/00; B29C45/14; B29C45/14336; B29C61/00; B29C70/74; B29C70/76; B29C70/763; E; E01; E01F; E01F13/00; E01F13/02; E01F13/022; E01F8/00; E01F8/0005; E01F8/0017; E01F8/0023; E01F9/00; E01F9/60; E01F9/688; E01F9/692; E04; E04H; E04H17/00; E04H17/14; E04H17/16; E04H17/1602
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
111 words
A method for making a framed panel comprising: providing a thermoplastic panel-forming material including central panel portions and peripheral portions surrounding said panel portions, at least part of said panel portions being molecularly oriented; forming a molten frame and embedding said peripheral portions of said panel-forming material in said molten frame during formation of said molten frame; solidifying said frame with said peripheral portions of said panel-forming material embedded therein; heating the molecularly oriented panel portions sufficiently to cause same to shrink and thereby tension said panel-forming material within said frame; and solidifying said panel-forming material in said tensioned condition of said panel-forming material to form an integral framed tensioned panel.
Claim 2
Independent Claim
111 words
A method for making a framed panel comprising: providing a thermoplastic panel-forming material including central panel portions and peripheral portions surrounding said panel portions, at least part of said panel portions being molecularly oriented; forming a molten frame and embedding said peripheral portions of said panel-forming material in said molten frame during formation of said molten frame; solidifying said frame with said peripheral portions of said panel-forming material embedded therein; heating the molecularly oriented panel portions sufficiently to cause same to shrink and thereby tension said panel-forming material within said frame; and solidifying said panel-forming material in said tensioned condition of said panel-forming material to form an integral framed tensioned panel.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein said molecularly oriented parts of said panel-forming material are formed by preliminarily stretching said parts below the glass transition temperature of said thermoplastic material to orient the molecules therein.
Claim 4
Dependent Claim
13 words
The method of claim 2, wherein said thermoplastic panel-forming material is a polyolefin.
Claim 5
Dependent Claim
10 words
The method of claim 3, wherein said polyolefin is polypropylene.
Claim 6
Dependent Claim
32 words
The method of claim 1 wherein said panel-forming material is a polygrid comprising molecularly oriented strands interconnected by less oriented junctions, said strands and junctions together defining a multiplicity of grid openings.
Claim 7
Dependent Claim
13 words
The method of claim 1, wherein said panel-forming material is a thermoplastic sheet.
Claim 8
Dependent Claim
21 words
The method of claim 1, wherein said forming step includes molding said frame about said peripheral portions of said panel-forming material.
Claim 9
Dependent Claim
15 words
The method of claim 7, wherein said frame is formed of a structural polymeric foam.
Claim 10
Dependent Claim
20 words
The method of claim 8, wherein said structural foam is injection molded about said peripheral portions of said panel-forming material.
Claim 11
Dependent Claim
51 words
The method of claim 1, wherein said forming step includes capturing said peripheral portions of said panel-forming material between mating faces of opposed mold members which together define a peripheral frame-forming mold cavity about said peripheral portions, injecting a molten frame-forming polymer into said mold cavity, and solidifying said frame-forming therein.
Claim 12
Dependent Claim
29 words
The method of claim 10, wherein said panel-forming material is a polygrid comprising molecularly oriented strands interconnected by less oriented junctions, said strands and junctions together defining grid openings.
Claim 13
Dependent Claim
68 words
The method of claim 11, further comprising slightly spacing the mating faces of said opposed mold members to provide a small gap to accommodate the thickness of the polygrid at the point where the peripheral portions thereof enter said mold cavity, providing elastomeric sealing means adjacent said gap, and squeezing portions of said sealing means into said gap prior to injecting molten frame-forming material into said mold cavity.
Claim 14
Dependent Claim
43 words
The method of claim 10, wherein said central panel portions of said panel-forming material comprise molecularly oriented strands interconnected by less oriented junctions said strands and junctions, together defining a multiplicity of grid openings, and said peripheral portions comprise a substantially unoriented selvedge.
Claim 15
Dependent Claim
38 words
The method of claim 13, further comprising a multiplicity of apertures defined in said selvedge, and wherein said molten frame-forming material is extruded into and through said apertures to increase the connection of the panel to the frame.
References Cited (Backward Citations)
US2681294A
Cited
US3523994A
Cited
US3729889A
Cited
US3895433A
Cited
US3930632A
Cited
US3975223A
Cited
US4140826A
Cited
US4269579A
Cited
US4214411A
Cited
US4756946A
Cited
US4374798A
Cited
US4536429A
Cited
US4618385A
Cited
US4590029A
Cited
US4584155A
Cited
US4531997A
Cited
US4695420A
Cited
US4626185A
Cited
US4769100A
Cited
US4743323A
Cited
US5132148A
Cited
US5078363A
Cited
US5034077A
Cited
US5308559A
Cited
US5184800A
Cited
US5527500A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-13 | 2001-04-14 | 2001-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-13 | 2005-04-14 | 2005-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-13 | 2009-04-14 | 2009-10-14 | $7700.00 | Window Closed / Lapsed |