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Publication numberUS3890754 A
Publication typeGrant
Publication dateJun 24, 1975
Filing dateOct 9, 1973
Priority dateOct 9, 1973
Publication numberUS 3890754 A, US 3890754A, US-A-3890754, US3890754 A, US3890754A
InventorsSpurdle Graham David
Original AssigneeSpurdle Graham David
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Corner bend in fibrous sheet material
US 3890754 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

United States Patent [1 1 Spurdle June 24, 1975 1 CORNER BEND IN FIBROUS SHEET MATERIAL [76] Inventor: Graham David Spurdle, 675 Alpine Ct., North Vancouver, British Columbia, Canada 22 Filed: Oct. 9, 1973 21 App]. No.: 404,228

[52] US. Cl 52/631; 52/211 [51] Int. Cl. F04c 2/00 {58] Field of Search 52/631, 211; 161/102, 106, 161/108 [56] References Cited UNITED STATES PATENTS 2,505,789 5/1950 Norquist 52/631 3,200,547 8/1965 Johnson 52/631 X 3,517,427 6/1970 Bainter et a1. 52/631 X 3,649,398 3/1972 Keith 52/631 UX 3,654,053 4/1972 Toedter 52/631 X 3,729,870 5/1973 Kualhein et a1 52/631 X Primary Examiner-Frank L. Abbott Assistant ExaminerCarl D. Friedman Attorney, Agent, or FirmCarver and Company [57] ABSTRACT A method of forming an exterior corner bend in iibrous sheet material in which a pair of parallel, overlapping, V-shaped grooves are formed across one side surface of the material so as to provide a pair of bevelled edge faces spaced apart by a triangular rib, filling the V-shaped grooves with a liquid settable rib and maintaining the sheet in its bent condition until the adhesive sets.

3 Claims, 3 Drawing Figures 1 CORNER BEND IN FIBROUS SHEET MATERIAL BACKGROUND OF THE INVENTION 1. Field of the Invention v This invention relates to forming exterior bends in fibrous sheet material, such as plywood sheeting, for finishing trim around doorways, window easements and the like. v

2. Prior Art Conventionally, trim around doorways and the like, has usually been made of finished dimensioned lumber which is stained or otherwise finished to match the wall panelling or door adjacent. With modern prefinished door skins in which the finished side can be a suitable plastic such as vinyl or paper which can be treated to simulate any type of wood it is very difficult, if not impossible, to obtain and finish solid wooden trim to obtain an exact match. Consequently doorway trim and the like, is now, in many cases, formed substrate material as the door and which has an exterior finish which matches, exactly, the finish of the door.

Individual members of the latter type of trim have a channel cross-section and are formed from a single finished piece of substrate which is suitably corner bent and glued to provide the required strength.

In prior art procedures for forming a corner bend a V-shaped groove is cut in the unfinished side of the piece through the various substrate thicknesses up to but not through the exterior finish. The groove is then filled with a suitable adhesive then bent to the desired angle along the V-shaped groove and held in position until the adhesive has set. The exterior corner bend thus formed usually presents an unbroken exterior finish, if the finish is vinyl. With exterior finishes of a fibrous nature such as paper, splitting of the finish sometimes occurs.

Furthermore an exterior corner as formed above presents a sharp edge which is susceptible to damage and cannot easily be repaired.

SUMMARY OF THE INVENTION The present invention provides a method for forming corner bends in sheet material of a rigid fibrous nature which provides a chamfered exterior corner and which is, consequently, not as readily damaged as sharp cornered corner bends.

Furthermore, the present method of forming corner bends reduces incidences of splitting of the exterior finish particularly where the finish material is of a fibrous nature, such as paper.

In accordance with the invention the corner bend is formed by cutting two parallel, over-lapping, V-shaped grooves across the unfinished side of the panel up to but not through the exterior finish so as to form a central triangular rib, filling the grooves with a suitable adhesive then bending the panel on lines coincident with the bottoms of the V-shaped grooves, and maintaining the bend until the adhesive has set.

A detailed description following, related to drawings, gives exemplification of methods according to the invention which, however, is capable of expression in method other than those particularly described and iilustrated.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a door jamb, trim members of which are formed in accordance with the invention.

FIG. 2 is an enlarged sectional view of a portion of a trim member prior to bending,

FIG. 3 is a sectional view illustrating a finished corner bend.

DETAILED DESCRIPTION Referring to the drawings, FIG. I is a transverse section of one side of a door jamb having a stop 1.0,jamb faces Ill and 12, and side trim 13 and 14 all of which are formed of thin plywood sheeting finished on one side which is corner bent to provide an unbroken finished surface.

The corner bends of the door stop and jamb faces are in extent, whereas, trim l3 and 14 have corner bends 15 and R6, less than 90 and corner bends l7 and 18 which are greater than 90. The exterior corner bends are all formed in the same manner.

Referring to FIGS. 2 and 3 which show a typical corner bend and a method of making the same, the numeral 21 designates a sheet of laminate fibrous material, for example plywood, which has an unfinished interior surface 22 and has a finishing veneer 23 applied, in a known manner, to its outer surface 24. The finish, can, conventionally be vinyl or paper or other known materials.

A pair of parallel, over-lapping, V-shaped grooves 25 and 26 are formed across the interior surface 22, the apeces 27-27 extending to, but not through, the exterior finish 23 so as to form a central triangularly shaped rib of wood 29 and a pair of panels 31 and 32 which have bevelled edge faces 33 and 34 and which are connected only by the exterior finishing veneer 23. The rib, for plywood one-eighth inches in thickness, suitably, a base length of one-sixteenth inches.

The V-shaped grooves are then filled with a suitable liquid adhesive 35, for example a hot melt glue having a polyethelene or polyester base, and the panels are then folded around fold lines represented by the apeces 2'727 of the grooves and maintained in a folded condition until the glue has set.

The apex angle and spacing of the V-shaped groove is such that when the panels 31 and 32 are bent to the desired angle, see FIG. 3, the panels meet at the juncture of the bevelled end faces and the inside surfaces of the panel. It will be seen that during bending the volume of the V-shaped grooves is reduced so that ideally excess glue is squeezed out onto the inside surface of the panels. This strengthens the exterior corner bend thus formed.

The provision of the central rib results in a ehamfer 31 rather than a sharp corner edge the deflection angle at each edge of the ehamfer being only one half of the corner bend angle. Due to the decreased deflection angle and due to the softening of the veneer by the hot glue, incidences of splitting of the finishing veneer, at the corner bend during production, is markedly reduced.

Furthermore the chamfered corner can withstand, without excessive damage, the impact of hard objects.

It is to be understood that although reference has been made to corner bending fibrous material having exterior finishing veneer the same method of corner 3 4 bending can be used with plywood sheets having no finneer and having side surfaces spaced from said bevishing veneer. In this case depth of the Vshaped elled end faces, grooves is only slightly less, approximately 8/1000 e. the inner edges of said sheet portions being in inChBS, than the thickness Of the Sheet material. ontact each other and Said end faces being I Claim? non-parallel to each other whereby a space is de- 1. An exterior corner structure for a rigid sheet of f1 fined by Said end faces of said sheetgpomons and brous material having a flexible sheet of finishing veneer on the exterior surface thereof comprising:

a. a pair of sheet portions connected by said veneer extending unbroken between the two sheet por- 10 said side surfaces of said central rib, and f. an adhesive substantially filling said space and bonded to said end faces and said side surfaces.

2. A corner bend as claimed in claim 1 in which the tions, b. said sheet portions being at substantially a right adheslve a hol melt glueangle to h other 3. A corner bend as claimed in claim 1 in which the said heet ortion h i b ll d d f triangularly shaped rib has a base length of substand. a central rib of triangular cross-section disposed tially One-sixteenth inches.

between said end faces and connected to said ve-

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2505789 *Jan 29, 1948May 2, 1950Norquist Glenn HGrooving laminated plywood
US3200547 *Jul 1, 1963Aug 17, 1965Standard Coated Products IncCorner molding
US3517427 *Sep 9, 1968Jun 30, 1970Winnebago Ind IncMethod of making a multisided structure
US3649398 *Aug 4, 1969Mar 14, 1972Ici LtdFoldable foam laminates
US3654053 *Nov 19, 1969Apr 4, 1972Re Flect O Lite CorpDecorative panel plate board or the like and method of fabricating same
US3729870 *Jun 19, 1970May 1, 1973Kvalheim AMethod and assembly of universal jamb and trim molding
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4265052 *Aug 17, 1979May 5, 1981Johnson Earl LStorm window construction
US4361995 *Feb 4, 1980Dec 7, 1982Isover Saint-GobainU-Shaped plasterboard
US4640857 *Jan 25, 1983Feb 3, 1987Meinan Machinery Works, Inc.Plywood
US4837977 *Nov 22, 1988Jun 13, 1989Mauro Gerald DWood clad windows
US4872296 *Dec 19, 1988Oct 10, 1989Duro-Last Roofing, Inc.Corner pieces for single-ply polymer-coated fabric core roof membranes and the product thereby formed
US5081793 *Jun 7, 1990Jan 21, 1992Mauro Gerald DWood clad window assembly and associated method
US5085027 *Sep 18, 1990Feb 4, 1992Herman Miller, Inc.Panel edge construction
US6616781Jul 9, 2001Sep 9, 2003Steven R. MayleOpen die system
US6620271Jul 9, 2001Sep 16, 2003Steven R. MayleOpen die system
US6754993Apr 18, 2002Jun 29, 2004Steven R. MayleAdjustable corner roof membrane and method of making the same
US6892499Apr 18, 2002May 17, 2005Steven R. MayleApparatus and method for sealing a vertical protrusion on a roof
US6892782Feb 26, 2003May 17, 2005Steven R. MayleApparatus and method for sealing a vertical protrusion on a roof
US7387149May 16, 2005Jun 17, 2008Mayle Steven RApparatus and method for sealing a vertical protrusion on a roof
US7739851 *Apr 4, 2007Jun 22, 2010Ppg Industries Ohio, Inc.Plastic spacer stock, plastic spacer frame and multi-sheet unit, and method of making same
US7810537Nov 15, 2007Oct 12, 2010Mayle Steven RApparatus and method for sealing a vertical protrusion on a roof
US7827761 *Apr 4, 2007Nov 9, 2010Ppg Industries Ohio, Inc.Plastic spacer stock, plastic spacer frame and multi-sheet unit, and method of making same
DE102006007522B4 *Feb 16, 2006Jan 24, 2013Warendorfer Küchen GmbHMöbelkorpus
Classifications
U.S. Classification52/631, 52/211
International ClassificationE06B1/34, E06B1/04
Cooperative ClassificationE06B1/34
European ClassificationE06B1/34