GB2058995A - Framework structure and kit therefor - Google Patents

Abstract

The invention provides a constructional kit comprising strips or sheets 6 each formed to be erectable into predetermined tubular form and for joining the resulting erected tubular members 2 together joining and fixing members 4 which are a mating sliding fit in the ends of the hollow tubular members and which are capable of securely receiving fixing means, e.g. screws 25 or bolts, whereby a tubular member 2 can be secured to a joining and fixing member 4 accommodated therein and whereby a structure comprising adjacent tubular members connected by such a joining and fixing member can be fixed to a support and/or to a member or structure to be supported. The strips or sheets may be formed with access holes 20 to facilitate rapid securement in tubular form. The fixing and joining members may have axial bores 40 from their end faces for accommodating strong elongate connecting rods or tubes 42; and/or they may be joined externally by reinforcing webs, their shape and size being modified to accommodate the latter. The kit can be assembled into various structures e.g. a display stand or a framework which can be secured to a cladding panel or between cladding panels. For increased permanence and strength the assembled structure may be provided with a coating of cured reinforced plastics. <IMAGE>

Description

SPECIFICATION Framework structure and kit therefor The present invention relates to a constructional kit and to structural members and structures made therefrom.

The kit according to the invention comprises strips or sheets each formed to be erectable into predetermined tubular form, and for joining the resulting erected tubular members together joining and fixing members which are a mating sliding fit in the ends of the hollow tubular members and which are capable of securely receiving fixing means (such as nails or screws or bolts etc.) whereby a tubular member can be secured to a joining and fixing member accommodated therein and whereby a structure comprising adjacent tubular members connected by such a joining and fixing member can be fixed to a support and/or to a member or structure to be supported. The strips or sheets may be in lay-flat tubular form.For joining adjacent tubular members end to end in rectilinear fashion, a simple joining member is used with the two tubular members being slid over its opposed ends; for other joints, two such simple joining members may be secured together in the required orientation with one tubular member carried by each, but for such joints it is possible to provide a single joining member of appropriate shape, such as one in the form of an angle piece (e.g. a right angle piece) or a T-piece.

By means of the tubular and joining members it is thus possible to form rapidly an extended rib or beam etc. or a framework which can be principally of inherently light weight and light duty material but which can have overall strength and be secured firmly to a support and/or itself act as a support for another member or structure.

The tubular members are suitably of cardboard.

The tubular members are conveniently formed from single-layer flat sheets or strips preformed with longitudinal fold lines for ready folding by the user into the predetermined tubular shape; the cardboard (or any similar or equivalent material which is used instead) may be folded to tubular form with its lateral edges overlapping and secured to one another, e.g. by adhesive or by stapling etc.

In an especially preferred embodiment each strip or sheet is erectable into a tubular member with its edge portions overlapping, the strip or sheet having holes (or press-out portions) spaced along its length and so disposed as to provide lateral openings into the erected tubular member facilitating the application of fixing means to secure the overlapping edge portions together. In another embodiment the lateral edges of the folded material may form a double-layer web extending inwardly from the tube wall, the fixing and joining members each having a longitudinal groove or slot to accommodate this web. At one or more intervals along the length of a tubular member, there may be a cut in the tubular wall forming a flap which is or can be folded inwardly, e.g.

at right angles to the tube axis, to support adjacent wall portions and hence strengthen the tube. Such cuts may of course be preformed in the flat sheet or strip from which the tubular member is made. Instead of the tube material being supplied in unfolded flat form it can be supplied in made-up lay-flat tubular form to be erected on insertion of the fixing and joining members. The fold lines in the material of the tube may be made by scoring or, in the case of a material like cardboard, by partial delamination locally along the fold lines. Where a rounded or bevelled edge is required, a plurality of closely spaced parallel fold lines are provided to form the edge.

The fixing and joining members, which may be of wood, preferably hardwood, can be predrilled laterally to accept the appropriate gauge screws or bolts for effecting securement to a support or for attachment thereto of another member or structure which is to be supported thereby. In one embodiment joining members are drilled (e.g. right through) to take internally threaded metal sleeves or ferrules, these being a force or broached fit in their drilled holes so as to be locked against turning relative to the member when engaged by the corresponding bolts or screws. Preferably such a sleeve or ferrule has at least one external projection or rib so that when forced into its drilled hole in the joining and fixing member it engages fixedly therewith so as to be locked positively against turning relative to the member on engagement with a bolt or screw.

The fixing and joining members may be hollow or of channel section, rather than being solid blocks, and in this case can advantageously be of metal or plastics material and are preferably laterally pre-tapped to accommodate fixing and/or joining screws or bolts.

In addition to its use for joining adjacent tubular members, a joining and fixing member can be slid within a tubular member to a region between its two ends to form an intermediate strong point for attachment to a supporting surface or for attachment thereto of another member or structure. In this case, it is of advantage for the tubular member to have small perforations spaced along its length so that the position of the internal joining and fixing member is readily ascertained.

Where the joining and fixing members are laterally predrilled or pretapped, it is preferred for the tubular members to have holes through their walls at positions which will register with the pre-drilled or pretapped holes when the joining and fixing members are in operative position, or for these positions on the walls of the tubular members to be marked by preprinting.

In one embodiment employing what may be regarded as hollow fixing and joining members, the latter, in addition to being predrilled laterally to accept screws or bolts etc., for securing them to the tubular members or to a support or to another member or structure which is to be supported, are provided also with longitudinal bores or channels extending therethrough from end to end. The joining and fixing members can then be threaded onto elongate connecting rods or tubes, e.g.

of metal, plastics or wood, and secured thereto by grub screws or pins through the laterally predrilled holes, to form an extremely strong skeleton or scaffolding framework to be covered by the neat outer cladding of tubular members.

Instead of and/or as well as reinforcing rods or tubes engaging as decribed above with internal bores in the joining and fixing members, spaced joining and fixing members may be joined externally by elongate reinforcing members (e.g. of rigid plastics material or of metal such as steel or aluminium alloy) which may for example be flat strips or anglesection pieces of appropriate conformation to fit the forming and fixing members, the combination being enveloped by the tubular members; this involves the joining and fixing members being of a shape and size to be a sliding fit within the combined reinforcing and tubular members. The heads of the fixing means (bolts, screws etc.) securing outer tubular members, reinforcing member and inner joining and fixing member together will usually be exposed externally, but can generally be positioned so as to be hidden in the completed structure.The reinforcing members will usually have slots and/or holes therethrough to accept the fixing bolts or screws etc.; "Dexion" (Trade Mark) is a suitable such product.

The tubular members, and correspondingly the joining and fixing members, may for example be of rectangular (e.g. square) section or of "top hat" section.

The described kit can be readily made up into a complete framework providing a flat surface or faces, e.g. for the mounting of flat showcards or other display material for exhibition and like short term display work; an advantage of the system here is that it it as readily dismantled for storage or further use as it is assembled. A framework assembled from the kit according to the invention can be clad with sheeting on one or both faces to constitute a partition, wall or bulkhead or for example to provide a complete wall mould for tanks (e.g. water tanks), other containers, ducting etc. For its light duty, short term and repeated usage, the kit according to the invention will be employed as described above without further treatment. For its more permanent and heavy duty usage, the framework after assembly and securing to cladding etc.

or to a support surface may be coated externally with a curable reinforced plastics composition (e.g. one reinforced with glass fibre), thus acting as a male mould for the composition which is subsequently cured to give a structure of enhanced strength and durability.

Additionally, or instead, the tubular members before assembly may be coated internally with such a curable plastics composition. Treatment with a curable reinforced plastics composition would not normally be necessary when the joining and fixing members are threaded on connecting rods or tubes or joined externally by reinforcing members, as described above, but this could be done if desired.

The kits employing members of "top hat" section will be used mainly for the formation of reinforcing or structural ribs, beams etc. on a substrate surface, rather than for the erection of frameworks. The tubular members of "top hat" section and the mating joining and fixing members are assembled into an extended rib or beam whose base is then adhered to the substrate surface. A curable reinforced (e.g. with glass fibre) plastics composition is then moulded over the rib or beam so as to coat its exposed surface and extend into engagement with the adjacent surface portions of the substrate, and the composition is then cured around the mould constituted by the rib or beam to form a structural member reinforcing the substrate surface and/or providing means by way of which another member or structure (e.g. a cupboard or like fixture) can be secured to the substrate surface.

The invention is further illustrated, by way of example only, by the following more detailed description to be taken in conjunction with the accompanying drawings, in which: Figure 1 is a perspective exploded view of a pair of tubular members and a joining and fixing member for connecting them end to end; Figure 2 is a plan view of a preformed cardboard strip from which tubular members as in Fig. 1 are made; Figure 3 is a side elevation view, in section, through a fixing and joining member of the type shown in Fig. 1, with various internally threaded ferrules in position in the predrilled holes; Figure 4 is a perspective view, in section, of "top hat" tubular and fixing members to be used as a male mould for the formation of a reinforcing rib of cured plastics composition; Figure 5 is a perspective view of a T-piece joining and fixing member; ; Figure 6 is a view, similar to Fig. 4, using a channel section joining and fixing member; Figures 7 and 8 show respectively in perspective and sectional side elevation view a joining and fixing member of the type shown in Figs. 1 and 3 but with an axial bore; Figure 9 is a perspective view of part of a structural framework according to the invention in which various spaced axially bored joining and fixing members are strung or threaded on and secured to elongate connecting members as well as being clad by the tubular members, and Figures 10 and ii are respectively a plan view of a preferred strip for use according to the invention and a perspective view of the tubular member erected therefrom.

In the drawings, like parts are indicated by like reference numerals.

Fig. 1 illustrates a pair of tubular members 2 of cardboard or like material and a joining and fixing member 4 over which the opposed ends of members 2 are a mating sliding fit whereby these two tubular members 2 may be connected together. Each tubular member 2 is made from a strip 6 as shown in Fig. 2, strip 6 being prescored or locally delaminated along parallel longitudinal lines 8 so that it can readily be folded along these lines into the square section tubular form of Fig. 1 with its edge portions 10 fully overlapping as shown in Fig. 1. These overlapping edges 10 are secured to one another by staples or adhesive (not shown). Members 2 could instead be supplied in lay-flat tubular form.

The fixing and joining member 4, which is of hardwood, is predrilled as at 1 6 to accept screws by means of which it may be attached to its tubular members and by means of which it may be secured to a supporting surface or have another member or structure secured to itself. The portions of the tubular members to be in register with the predrilled holes of member 4 are marked by preprinting as at 1 8 or are already perforated.

Along at least one wall of each tubular member 2 a line of small perforations 20 is formed, so that should an intermediate fixing member 5 be positioned within the tubular member (as indicated by dotted lines in Fig.

1), the latter can readily be located and positioned precisely.

Fig. 3 illustrates a preferred form of predrilling adopted for the member 4 of Fig. 1. The member is counter-bored right through as shown at the positions 16, the holes thus formed accommodating internally threaded metal ferrules 24 into which mating screws can be threaded for the mounting purposes indicated above. The ferrules are hammered into the predrilled holes, and have external ribs or projections which bite into the material of the member when they are driven home to secure them against rotation relative to the member. The arrangement of ferrules shown in Fig. 3 is purely exemplary.

Fig. 4 illustrates a "top hat" section embodiment. Here the edge portions 26 of member 2 are folded to extend together perpendicularly inwardly from the base of the tube, and joining and fixing member 4 has a longitudinal groove 28 which accommodates and secures these edge portions. The edges 8 of member 2 are rounded, due to the provision of closely spaced fold lines 30 for each edge.

As indicated above, the "top hat" tubular and joining and fixing members are intended principally not for the formation of frameworks, but to provide male moulds for the formation on a substrate surface of a reinforcing and/or structural stringer, rib, beam or assembly etc.

Accordingly, there are indicated in Fig. 4 a substrate surface 1 and a coating 3 of cured, reinforced plastics composition moulded over the "top hat" section male mould and extending into contact with the adjacent surface portions of the surface 1. Fig. 4, of course, shows only part of a tubular member 2 and joining and fixing member 4; in practice, a plurality of the tubular members 2 would be joined together by means of joining and fixing members 4 in the manner illustrated in and described with reference to Fig. 1 in order to form the elongate male mould; advantageously, similar members 4 would be positioned within the outer ends of the resulting male mould, to give adequate support for these extremities of the mould, and at least one further joining and fixing member as suggested at 5 in Fig. 1 but of appropriate mating "top hat" section could be positioned between the ends of any tubular member to provide additional support therefore and/or to constitute a fixing point. Purely for the purpose of forming the male mould, it may not be necessary to fix the tubular members to the joining and fixing members in the manner described with reference to Figs. 1 to 3.

However, it can still be of advantage for the joining and fixing members to be predrilled and the tubular members marked or perforated correspondingly, to facilitate the use of the joining and fixing members as strong points for the attachment of a fixture or other member to the finished moulded article; thus where a predrilled hole in a joining and fixing member is to be used as a fixture point in this way, a member such as a screw or pin can be positioned in the hole so that it projects above the surface of the plastics composition subsequently moulded therearound, the member being removed after curing. The elongate male mould, as or after it is made up from the tubular and joining and fixing members, is secured to the substrate surface in the orientation illustrated, preferably by means of an adhesive which could be the curable liquid component of the reinforced plastics composition.The male mould, being light, is readily adhered even to wall or ceiling surfaces without the need for heavy or constant pressure to prevent it moving under gravity; the reinforced plastics composition is then moulded in close contact over the exposed surfaces of the male mould and the adjacent surface portions of the substrate and then cured to yield a strong reinforcement for the substrate. The reinforcing material of the plastics composition will frequently be glass fibres, but can comprise other fibrous and/or non fibrous material.

The fixing and joining member 4 of Fig. 5 can have a tubular member over each of its three legs. The predrilled holes 1 6 can be provided with threaded ferrules as in Fig. 3.

Fig. 6 shows another "top hat" section embodiment where the fixing and joining member 32 is a metal or plastics channel section, the holes 1 6 (optional) therethrough being internally threaded. As in the case of Fig. 4, Fig. 6 indicates the use of the "top hat" section as a male mould for the formation on substrate surface 1 of a rib of cured reinforced plastics composition 3. The points made in connection with the Fig. 4 embodiment apply equally to that illustrated in Fig.

6.

Figs. 7 and 8 illustrate a fixing and joining member of the same general type as that shown in Figs. 1 and 3, with the modification that it is formed with an axial bore 40 so that it can be strung or threaded onto a rod or tube 42 as indicated in dotted lines in Fig. 7.

Fig. 8 shows the joining member 4 threaded onto two tubes 42. A connecting rod or tube 42 may be secured to a joining and fixing member 4 as shown in Fig. 8, by means of fixing means extending through one or more of the predrilled holes 1 6 into engagement with the rod or tube to clamp it in the bore 40. Thus ferrules 24 may be of such a length that, when driven home as a force or broached fit in predrilled holes 16, they engage the surface of the rod or tube 42 to pin it securely in the bore 40. Another possibility is for the ferrules 24 to be open-bottomed, so that the screws or bolts 25 accommodated thereby can be screwed down to project through the ferrule bottoms to constitute grub screws securing the rod or tube 42 in the axial bore 40.The shaped joining and fixing members (e.g. angle pieces, T-pieces, etc) may likewise have axial bores through each end face for accepting a connecting rod or tube through each end face, the connecting rods or tubes being secured in the same manner as described with reference to Fig. 8.

Thus a very strong but lightweight skeleton may be built up clad with the tubular members 2 of neat outward appearance; the tubular members will be fitted, of course, as the skeleton or scaffolding is built up. In these embodiments, the joining and fixing members will be supplied with predrilled holes 1 6 to allow for both the fixing of the connecting rods or tubes 42 and the purposes previously described-securing to the tubular members and securing to a supporting surface and/or to a member to be supported. The connecting rods or tubes may be of any of a variety of materials according to the requirements as to strength and weight for the particular embodiment. The rods, and especially tubes, may suitably be of metal, e.g. aluminium, but could be of wood or plastics material etc.

Fig. 9 illustrates part of an assembled framework of the type just described, involving rectilinear, angled and T-piece joining and fixing member 4, tubular connecting members 42 (e.g. of aluminium), and tubular cladding members 2 of cardboard. Screws or bolts through some of the predrilled holes 1 6 act to secure the members 4 and tubes 42 firmly together in a manner described with reference to Fig. 8, and screws or bolts into other of the holes 1 6 can secure the resulting framework to a cladding panel 44. A further cladding panel could be secured in the same way to the other face of the framework.In other arrangements, the same screws or bolts which secure the cladding to the framework can constitute also the grub screws which secure together the members 4 and 42 or it may be for ferrules 24 which act as pins securing together members 4 and 42, these ferrules then receiving the screws or bolts by which the framework is fixed to a cladding. The tubular members 2 are secured to members 4 by sandwiching between the surface of members 4 and the heads of the fixing screws or bolts or possibly flanges on the heads of the ferrules 24. For clarity, the ferrules 24 and the screws and bolts are not shown in Fig. 9, but it is evident how they will be applied.

Instead of or in addition to internal reinforcing rods or tubes 42, the external surfaces of adjacent joining and fixing members may be joined by reinforcing webs (e.g. flat strips or complementary angle-section webs) of "Dexion", with bolts or screws securing the outer tubular member and the intermediate reinforcing web to the adjacent fixing and joining members within; in this case, the shape and size of the joining and fixing members is modified to accommodate the reinforcing webs.

Figs. 10 and 11 illustrate a preferred strip or sheet for use according to the invention, which can be erected into and secured in its predetermined tubular form with particular ease and rapidity. The strip 6 has single longitudinal score lines 8 and multiple longitudinal score lines 30 so that it is readily folded into a "top hat" section tubular member 2 as shown in Fig. 11; unlike the "top hat" tubular member shown in Fig. 6, the overlapping edge portions 12 in the embodiment of Fig.

10 and 11 form one of the sloping sides of the tubular member rather than its base.

Formed at spaced intervals along the length of strip portion 13 (which forms the base of the erected tubular member) at or adjacent to its margin with outermost score line 8 are openings 46; the holes or openings 46 appear at the edge of the base 1 3 of the erected tube adjacent to the overlapping edge portions 12, and provide access to the interior of the tubular member for the anvil of a stapler by means of which the overlapping edge portions may be fixed together. Provision of the holes or openings 46 thus allows great lengths of tubular member to be erected and secured in tubular form very rapidly and effeciently.

Stapling is a preferred method of securing together the overlapping portions 1 2 (it being of particular advantage that the sharp free ends of the applied staples 7 will be within the tubular member rather than being exposed at its exterior), but the holes or openings do of course provide ready access for the application of other types of fixing member if desired. Instead of holes or openings 46, it is of course possible for their outline to be defined by lines of weakening of the cardboard or like material of strip 6 (e.g. by partially cutting through the strip), so that the outlined portions can readily be pressed or pushed out from the strip or erected tube to leave the required openings. It is preferred for the openings 46 to be located in the base 13, but they can of course be elsewhere provided they are adjacent to the overlapping edge portions.

The holes or openings 46 may also serve to assist in the location of a fixing and joining member at an intermediate region along the tubular member. Tubular members as shown in Fig. 11 are suitable for use, along with corresponding joining and fixing members, in the same manner as described with reference to Fig. 6.

The invention also provides a strip or sheet formed to be erectable into predetermined tubular form with its longitudinal edge portions overlapping, the strip or sheet having openings, or press-out portions spaced along its length and positioned to provide lateral openings into the erected tube facilitating the application of fixing means to secure the overlapping edge portions together. The tubular member will usually have at least one substantially planar surface, e.g. being of polygonal cross-section optionally with a rounded edge or edges.

Whilst wood, metal and plastics have been suggested for the fixing and joining members, other materials can be used, provided that they have the required weight and strength for the purpose to which the assembly is to be put. One might, for example, employ solid members such as those of Figs. 2 or 4 made of bonded filamentary tow or fibres (of the type used as tobacco smoke filters and ink reservoirs) impregnated with hardened resin.

The porous bodies, e.g. of bonded cellulose acetate filamentary tow, are impregnated with the resin in uncured liquid form and the resin is then cured, yielding lightweight members of considerable strength and rigidity. The bonded fibrous or filamentary bodies are readily produced continuously in any of a range of cross-sectional shapes and sizes.

Using appropriately shaped (e.g. selected from straight, angled, T-piece, cruciform, etc.) joining and fixing members, the illustrated embodiments can be made up into a variety of structures. A framework, or separate ribs, assembled from the kit may be secured, by way of the joining and fixing members, to a cladding panel, or to two opposed cladding panels. For increased permanence and strength the tubular and fixing and joining members, after assembly and where appropriate after attachment to a panel or other member, may be coated with a curable reinforced (e.g. glass fibre reinforced) plastics composition which is then cured to yield a lightweight product of great strength.

Claims (25)

1. A constructional kit comprising strips or sheets each formed to be erectable into predetermined tubular form, and for joining the resulting erected tubular members together joining and fixing members which are a mating sliding fit in the ends of the hollow tubular members and which are capable of securely receiving fixing means whereby a tubular member can be secured to a joining and fixing member accommodated therein and whereby a structure comprising adjacent tubular members connected by such a joining and fixing member can be fixed to a support and/or to a member or structure to be supported.

2. A kit according to claim 1 wherein the joining and fixing members are predrilled laterally to accept fixing screws or bolts.

3. A kit according to claim 2 including internally threaded ferrules for location in the lateral bores of the joining and fixing members to accept fixing screws or bolts.

4. A kit according to claim 1, 2 or 3 wherein the strips or sheets are of cardboard or like material.

5. A kit according to any of claims 1 to 4 wherein the strips or sheets are in lay-flat tubular form.

6. A kit according to any of claims 1 to 4 wherein each strip or sheet is erectable into a tubular member with its edge portions overlapping, the strip or sheet having holes and/ or press-out portions spaced along its length and so disposed as to provide lateral openings into the erected tubular member facilitating the application of fixing means to secure the overlapping edge portions together.

7. A kit according to any of claims 1 to 6 wherein each tubular member is formed by folding a strip or sheet so that its lateral edges form together a web extending inwardly from the tube wall, the joining and fixing members each having a longitudinal groove or slot to accommodate this web.

8. A kit according to any of claims 1 to 7 wherein axial bores extend from end faces of the joining and fixing members, the kit including elongate connecting rods or tubes for accommodation in said axial bores.

9. A kit according to any of claims 1 to 8 wherein the joining and fixing members and erected tubular members are of "top hat" section.

10. A kit according to any of claims 1 to 8 including elongate reinforcing webs for joining adjacent spaced fixing and joining members externally, the fixing and joining members being a sliding mating fit within the space defined by the combined reinforcing webs and tubular members.

11. A constructional kit substantially as hereinbefore described with reference to Figs.

1 to 3 of the accompanying drawings.

1 2. A constructional kit substantially as hereinbefore described with reference to Figs.

1 to 3 and 5 of the accompanying drawings.

1 3. A constructinal kit substantially as hereinbefore described with reference to Fig.

4 or 6 of the accompanying drawings.

14. A constructional kit substantially as hereinbefore described with reference to Figs.

7 and 8 of the accompanying drawings.

1 5. A constructional kit substantially as herein before described with reference to Figs.

7 to 9 of the accompanying drawings.

16. A constructional kit substantially as hereinbefore described with reference to Figs.

10 and 11 of the accompanying drawings.

1 7. A structure assembled from a kit according to any one of claims 1 to 1 6.

1 8. A structure according to claim 17 in which at least one tubular member has a mating member therewithin between its ends to provide an additional strong point or fixing point.

19. A rib or framework according to claim 1 7 or 1 8 secured by way of the joining and fixing members to a cladding panel or between two opposed cladding panels.

20. A structure according to claim 17, 18 or 1 9 having the assembled tubular and fixing and joining members coated with a cured reinforced plastics composition.

21. An assembled framework substantially as hereinbefore described with reference to Fig. 9 of the accompanying drawings.

22. An elongate rib according to claim 1 7 or 1 8 as appendant on claim 10 secured by its widest face to a substrate surface and having over its other faces and over the adjacent portions of the substrate surface a moulded and cured coating of reinforced plastics composition.

23. A rib according to claim 22 substantially as hereinbefore described with reference to Fig. 4 or 6 of the accompanying drawings.

24. A strip or sheet formed to be erectable into predetermined tubular form with its longitudinal edge portions overlapping, the strip or sheet having openings, or press-out portions spaced along its length and positioned to provide lateral openings into the erected tube facilitating the application of fixing means to secure the overlapping edge portions together.

25. A strip or sheet according to claim 24 erected into tubular form with its overlapping edge portions secured together.