GB2135750A - A method of manufacturing a foldable structure - Google Patents

Abstract

A method of manufacturing a foldable structure which, when folded, produces an edge or corner profile which is preferably curved. A longitudinally extending recess 4 is machined in a panel 1 so that there is formed in the recess a support rib 5 and curved surfaces 6 and 7 which are separated by the support rib and extend towards one another. A flexible bridging member 12 is located in the recess 4 to bridge the profiling surfaces 6 and 7 and be supported on the rib 5. A second longitudinally extending recess 14 is now machined in the opposite face of the panel 1 to break through into the recess 4 on opposite sides of the rib 5 so that the panel is divided into two panel parts and the rib 5 is cut away for removal. The panel parts remain connected by a foldable region constituted by the flexible member 12 which is adhesively secured to both those parts. A second flexible bridging member 13 may be applied as a facia sheet. Channels 10 and 11 are machined in the recess 4 to alleviate the flow of adhesive on to the curved surfaces 6 and 7. <IMAGE>

Description

SPECIFICATION A method of manufacturing a foldable structure TECHNICAL FIELD AND BACKGROUND ART This invention relates to a method of manufacturing a foldable structure.

More particularly, the invention concerns the manufacture of a foldable structure which, when folded, produces an edge or corner the profile of which is other than sharp, that is to say the corner or edge profile is not constituted by a single apex. Usually, the method of the present invention will be applied to the production of an edge or corner having a curved profile or a multi-faced polygonal profile.

In the manufacture of a foldable structure from a substantially rigid panel member of chipboard or any other type of wood sheeting to enable the panel member to be folded into, say, a cabinet or box-like structure, it has hitherto been proposed (for example in Patent Specification GB A 1,563,942 and in our Patent Specification GB-A-2,054,086) to manufacture the foldable structure predominantly from the panel member by machining in one face of that member a longitudinally extending recess having two curved surfaces which extend towards one another. A flexible bridging member is then adhesively secured to the panel so that it bridges the two curved surfaces in the recess.A second longitudinally extending recess is then machined in the second face of the panel so that it breaks into the first recess to divide the panel into two panel parts with the flexible bridging member forming a foldable region between the panel parts. Following the application and securing of the flexible bridging member to the panel member and prior to the machining of the second recess to divide the panel, it may be found that there is insufficient stability in the flexible bridging member over the region where it bridges and is out of contact with the two curved surfaces of the recess.This instability may be reflected in bowing of the flexible bridging member into the recess where that bridging member is a thin lamina or facia sheet (as proposed in Specification 1,563,942) or where the flexible bridging member is to be machined or otherwise handled (for example as is proposed for the bridging member of cork or other flexible material having a degree of resilience to provide a cushioning effect as discussed in our Specification 2,054,086 where it is usual for the bridging material to be machined on the panel to which it is secured to provide a flat surface for the reception of a thin flexible facia sheet) prior to the division of the panel member.The lack of stability in the flexible bridging member can adversely affect the resistance to damage of, and the machining application of adhesive or other working on, the bridging member prior to the panel member being divided with the cutting of the second recess. It is an object of the present invention to provide a method of manufacturing a foldable structure which alleviates the aforementioned disadvantages so that a relatively stable configuration can be provided for the bridging member prior to the panel member being divided into the panel parts for folding.

STATEMENT OF INVENTION AND ADVAN TAGES According to the present invention there is provided a method of manufacturing a foldable structure which, when folded, produces an edge or corner, the profile of which is other than sharp and which comprises forming longitudinally extending recess means and support means in a first face of a panel member so that said recess means comprises two corner profiling surfaces extending towards one another and said support means is positioned laterally between and spaces said profiling surfaces; securing to the panel a flexible bridging member to bridge said profiling surfaces and be supported by said support means, and forming second longitudinally extending recess means in the second face of the panel so that the second recess means breaks through into the recess means in the first face to divide the panel member into two panel parts and cut away the support means for removal thereof and to form a foldable region constituted by the flexible bridging member between the two panel parts.

The present invention further provides for a foldable structure when manufactured by the method specified in the immediately preceding paragraph.

By the method of the present invention the flexible bridging member can be supported by the support means out of conact with the two corner profiling surfaces and thereby be restrained by the support means from bowing or otherwise being deformed out of the normal plane of that member prior to the panel member being divided into the two foldable panel parts.The present invention was primarily developed as an improvement to the method disclosed in our Patent Specification 2,054,086 to alleviate the deflection of a cork bridging member (or such a member of a material having similar flexible and cushioning properties) during machining of that bridging member so that it is co-planar with the first face of the panel member and also during the subsequent application of adhesive to that bridging member and the first face of the panel member for securing a flexible lamina or facia to the exposed first face of the panel member and the cork bridging member. It will be appreciated however that the support provided by the support means may be advantageous where an intermediate cushioning layer is omitted and a flexible facia lamina is applied to the panel member (for example as envisaged by the disclosure in U.K.Patent 1,563,942) so that the facia lamina is supported against deflection and possible damage into the underlying recess prior to the panel being sub-divided.

Having in mind the proposal in our aforementioned GB Specification 2,054,086 it is preferred that the bridging member is located in the recess means in the first face of the panel member and is adhesively secured in that recess means. When so located and secured the bridging member may be machined to be co-planar with the first face of the panel member. A second flexible bridging member (which may conveniently be regarded as a facia sheet or lamina) will usually be adhesively secured to the exposed first face of the panel member and to (and over) the flexible bridging member within the recess means to divide the panel into the two panel parts for folding.Preferably the recess means within which the flexible bridging member is accommodated is provided with longitudinally extending lands which are located adjacent to the corner profiling surfaces and on the sides of those surfaces remote from the support means so that the bridging member is adhesively secured to those lands.

As will be gathered from the aforegoing, the flexible bridging member together with any second flexible bridging member or facia sheet which may be applied over the first bridging member will usually be adhesively secured as part of the foldable structure. Conventional practice is to apply the adhesive by roller or brush to the panel member to which the flexible bridging member is to be secured.

It is most advisable that the corner profiling surfaces and also the surface of the flexible bridging member which is to be substantially moulded around those profiling surfaces remain clear of adhesive-thereby alleviating the retention of dust particles and the like which may be trapped within the edge or corner structure and present an unacceptable irregular profile to the surface of the corner or edge.

To alleviate this problem it is preferred that the method includes forming longitudinally extending channels adjacent to the corner profiling surfaces and on the sides of those surfaces remote from the support means, said channels alleviating adhesive which is applied for securing the bridging member from flowing on to the corner profiling surfaces.

In addition to the corner profiling surfaces being maintained clear of adhesive it is preferred that the support means are also retained clear of adhesive to ensure that there is no adhesion between the support means and the bridging member supported thereby; in this way when the second recess means breaks through into the recess means in the first face to divide the panel member into the two panel parts, the support means may be cut away and drop freely from between the two panel parts (thereby alleviating the necessity to machine away the support means up to the face of the bridging member). Preferably the support means is formed with a supporting face which abuts the bridging member and is substantially co-planar with the faces of the panel member to which the bridging member is adhesively secured.

The support means is preferably constituted by a longitudinally extending rib positioned between the two corner profiling surfaces and formed during the machining of those profiling surfaces. Usually the rib will be continuous longitudinally and the two corner profiling surfaces will be symmetrical about the rib. It will be appreciated however that there may be two or more longitudinally extending and laterally spaced ribs or similar support forms which provide several support positions for the bridging member over the recess.

The corner profiling surfaces will usually be smooth curves to provide for a curved corner or edge as envisaged by the aforementioned prior Patent Specifications. As an alternative example the corner profiling surfaces may cqmprises flat faces so that the resultant edge or corner on the folded structure has a generally polygonal profile.

DRAWINGS One embodiment of the present invention as applied to the manufacture of a foldable structure which when folded produces a curved edge will now be described, by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 1 is a lateral section through a panel member from which the foldable structure is to be formed, and Figures 2 to 5 show the sequential steps by which the panel member of Fig. 1 is manufactured into the curved corner structure.

DETAILED DESCRIPTION OF DRAWINGS A substantially rigid panel member 1 of, for example, chipboard has substantially flat parallel faces 2 and 3. Machined in the face 2 is a longitudinally extending recess 4 having a centrally disposed longitudinally extending rib 5. The recess 4 is symmetrical about the rib 5 and comprises two curved corner profiling surfaces 6 and 7 which are located on opposite sides of and are laterally spaced by the rib 5. The curved surfaces 6 and 7 extend towards each other and have an arcuate curvature, the extent and radius of which is deter mined according to the angle of the corner which is to be provided for the foldable structure. Extending along the marginal edge re gions of the recess 4 are longitudinally extending flat lands 8 and 9 which are stepped down through right angle shoulders from the face 2 (if required the aforementioned shoul der can be other than right angles as envi saged in our GB 2,054,086).

Located between the flat lands 8 and 9 and the curved profiling surfaces 6 and 7 to which those lands are respectively adjacent are longitudinally extending channels 10 and 11.

The rib 5 has a support face 5a which is coplanar with the flat lands 8 and 9. The lands 8 and 9 are coated with an adhesive and a flexible bridging member in the form of a cork sheet or insert 1 2 is located as a substantially complementary fit within the recess 4 (as shown in Fig. 2) to be seated on the lands 8 and 9. The cork insert 1 2 bridges the curved profiling surfaces 6 and 7 and abuts the face 5a to be supported by the rib 5. The adhesive bonds the cork insert 1 2 to the lands 8 and 9. The support face 5a is maintained clear of adhesive as are the curved surfaces 6 and 7.

The channels 10 and 11 conveniently serve as moats for the lands 8 and 9 respectively to alleviate the flow of adhesive from the lands 8 and 9 onto the curved faces 6 and 7.

It will be seen from Fig. 2 that the cork bridging member 1 2 stands proud of the panel face 2 and this will be quite usual (although the possibility is envisaged of fitting in the recess 4 a cork insert the thickness of which makes the cork flush with the face 2).

With the cork insert proud of the panel 2, the insert and panel are subjected to a sanding or similar machining operation to ensure that the cork insert is level with the face 2 of the panel. During this sanding operation the support presented by the rib 5 provides a degree of stability to the cork insert and alleviates the insert from bowing into the recess under the sanding or machining pressure.

Following the aforementioned sanding or machining operation (or when the cork insert 1 2 and face 2 are otherwise co-planar), a layer of adhesive is brushed or rolled over the level surface presented by the face 2 and the cork insert. During the application of this adhesive the cork bridging member 1 2 is again supported by the rib 5 against bowing into the recess 4 under the pressure with which the adhesive is applied. A second flexible bridging member in the form of a flexible lamina or facia sheet 1 3 (which is usually of plastics) is applied over the surface of the cork insert 1 2 and the face 2 of the panel to both of which it is bonded by the adhesive.Again the rib 5 will support the cork insert 1 2 against deflection under the pressure of applying the sheet 1 3.

To permit the structure to fold, a recess 14 of generally "V" shape is machined in the face 3 of the panel 1 to break through the panel into the recess 4 on laterally opposite sides of the rib 5 as indicated by the broken lines 1 4 in Fig. 3. As will be seen from Figs.

3 and 3, upon completion of the recess 14, the rib 5 is to be cut away from the panel while the panel is divided into two panel parts 1 a and 1 b. The cut away rib 5 is readily removable from between the panel parts 1 a and 1 b as are dust and chippings since the surfaces 6 and 7 of the panel parts, the exposed surface of the cork insert 1 2 which opposes the surfaces 6 and 7 and the inclined faces 1 5 and 1 6 formed during machining of the recess 14 are substantially clean and free of adhesive.

The panel parts 1 a and 1 b are interconnected by a foldable region constituted by the flexible bridging members 12 and 1 3 which are adhesively secured to those parts. Similarly to the discussion in our Patent GB 2,054,086, the panel parts 1 a and 1 b are folded so that the faces 1 5 and 1 6 move into abutment and form the structure shown in Fig. 5 having a smoothly profiled curved edge. In Fig. 5 the corner structure has the panel parts 1 a and 1 b disposed at right angles so the faces 1 5 and 1 6 of the "V" shaped recess 14 are at 90 to one another while the arcuate profiling surfaces 6 and 7 each extend through an arc of 45 . It will be appreciated that if the angular relationship between the panel parts 1 a and 1 b is increased or decreased from the right angle shown in Fig. 5 then corresponding changes will be required to the extent and profile of the corner profiling surfaces 6 and 7 and to the angular relationship between the inclined faces 15 and 16.

Claims (11)

1. A method of manufacturing a foldable structure which, when folded, produces an edge or corner, the profile of which is other than sharp and which comprises forming longitudinally extending recess means and support means in a first face of a panel member so that said recess means comprises two corner profiling surfaces extending towards one another and said support means is positioned laterally between and spaces said profiling surfaces; securing to the panel a flexible bridging member to bridge said profiling surfaces and be supported by said support means, and forming second longitudinally extending recess means in the second face of the panel so that the second recess means breaks through into the recess means in the first face to divide the panel member into two panel parts and cut away the support means for removal thereof and to form a foldable region constituted by the flexible bridging member between the two panel parts.

2. A method as claimed in claim 1 which comprises adhesively securing the bridging member to the panel other than on the support means and on the corner profiling surfaces.

3. A method as claimed in either claim 1 or claim 2 which comprises locating the bridging member in the recess means in the first face and adhesively securing the bridging member in said recess means.

4. A method as claimed in claim 3 which comprises locating the bridging member in the recess means so that said member stands proud of the first face of the panel and machining or otherwise removing material from the bridging member to make that member co-planar with the first face of the panel.

5. A method as claimed in either claim 3 or claim 4 which comprises adhesively securing over the bridging member in the recess means and to the first face -of the panel member a second flexible bridging member.

6. A method as claimed in any one of claims 3 to 5 which comprises forming in the recess means longitudinally extending lands adjacent to said corner profiling surfaces and on the sides of those surfaces laterally remote from the support means and adhesively securing the bridging member or the first bridging member to those lands.

7. A method as claimed in any one of the preceding claims which comprises forming longitudinally extending channels adjacent to the profiling surfaces and on the sides of those surfaces laterally remote from the support means, said channels alleviating adhesive which is applied for securing the bridging member from flowing onto the corner profiling surfaces.

8. A method as claimed in any one of the preceding claims which comprises forming on support means a supporting face which abuts the bridging member or the first bridging member and is substantially co-planar with the faces of the panel member to which the bridging member is adhesively secured.

9. A method as claimed in any one of the preceding claims which comprises forming curved corner profiling surfaces so that the structure when folded produces a curved edge or corner.

10. A method as claimed in any one of the preceding claims which comprises forming a longitudinally extending support rib positioned between the two corner profiling surfaces and cutting through the panel member with the second recess means to break into the recess means in the first face of the panel so that the support rib is cut away to be removable from between the two panel parts.

11. A method of manufacturing a foldable structure substantially as herein described with reference to the accompanying illustrative drawings.

1 2. A foldable structure when manufactured by the method as claimed in any one of the preceding claims.