WO2006114589A1 - Structural joint - Google Patents

Abstract

A joint (1, 11, 12) permits assembly of a structure, such as a storage rack (15), from a number of separate components (2, 3, 13, 21, 22, 23, 24, 25). The joint (1, 11, 12) is made up of two pairs of parallel tongues (4), each pair extending from an end of a respective first elongate structural element (2, 14, 22, 23), the tongues (4) defining between them a mortise slot (7) when said ends are brought together. A part-tenon (6) extends from an end of each of two second elongate structural elements (3, 14, 21, 23), so that one part-tenon (6) is insertable into the mortise slot (7) from each side, the two part-tenons (6) together filling the mortise slot (7). Cooperable studs (10) and recesses (9) on opposed surfaces of the tongues (4) and part-tenons (6) hold the joint (1, 11, 12) together, with the first and second structural elements (2, 3, 14, 21, 22, 23) in a generally cruciform configuration. A modular structure (15) may be built up by means of a plurality of identical joints (1, 11, 12).

Description

STRUCTURAL JOINT

The present invention relates to a joint for fastening together a plurality of structural members. More particularly but not exclusively, it relates to a joint connecting a plurality of members in a generally cruciform arrangement. It further relates to structural elements capable of forming such a joint, and to structures, particularly modular structures, constructed using such joints.

While a wide range of joints for connecting structural members are known, both in traditional carpentry and in structures employing more modern materials, these will each have their own particular advantages and disadvantages. An increasingly important requirement is that a joint should be quick and easy to fit together, while being stable and robust once assembled, even for joints for which disassembly may be envisaged.

One area in which such joints would be particularly useful is storage structures, such as bottle racks, shoe racks and so forth, which are frequently supplied as kits of parts for a user to assemble. A further requirement of such kits is that they should involve a minimum number of different types of component. A rack, etc, that may be assembled from a stock of identical modules is cheaper and easier to produce than one involving many different parts (particularly if mass-produced plastics modules are employed). It will also probably be easier for the user to put together (e.g. compared to a rack comprising numerous different clips, bolts, and so forth).

Similar consideration will apply to items of furniture, which are increasingly often supplied as a kit of parts, including miscellaneous connectors, particularly in the case of office and commercial furniture. A joint that may be rapidly and reliably assembled is highly likely to find uses in other applications, not necessarily limited to the above.

It is hence an object of the present invention to provide a joint for connecting a plurality of structural elements that is straightforward to assemble and strong and stable in use. It is also an object of the present invention to provide structural elements capable of being assembled into such a joint, and a structure made up from such elements by means of such joints. It is a further object of the present invention to provide a structure assemblable from a plurality of substantially identical modular structural elements by means of such joints, and to provide such modular structural elements.

According to a first aspect of the present invention, there is provided joining means to connect a plurality of structural elements comprising first structural element means defining mortise slot means, two second structural elements each provided with respective tenon means, insertable into said mortise slot means from opposite ends thereof and so conformably shaped as together substantially to fill the mortise slot means, and means to retain each tenon means within the mortise slot means. Preferably, each tenon means is substantially identically shaped.

Advantageously, each tenon means extends substantially through the mortise slot means.

In a preferred embodiment, the first structural element means comprises two third structural elements, so conformably shaped as to be assemblable to define the mortise slot means therebetween.

Advantageously, the two third structural elements are provided with means to retain them so assembled.

The means to retain the third structural elements may comprise said means to retain the tenon means.

The retaining means may secure each tenon means to each of the third structural elements.

The retaining means may comprise adhesive means.

The retaining means may comprise connector means, such as dowel means or screw means.

Preferably, the retaining means comprises detent means. Said detent means may comprise stud means located on a one of a tenon means and the first structural element, and cooperable recess means located on the other of said tenon means and the first structural element.

Optionally, the detent means may comprise stud means located on each tenon means so as to be cooperable with respective recess means located on each third structural element.

The recess means may conveniently comprise aperture means extending through a wall of the mortise slot means.

Preferably, each third structural element is provided with a pair of substantially parallelly- extending spaced-apart tongue means, each cooperable with a corresponding tongue means of the other third structural element to form a respective wall of the mortise slot means.

Advantageously, said tongue means are so conformably shaped as to form respective continuous walls of the mortise slot means.

Each tongue means may extend substantially across an entire width of the mortise slot means.

Preferably, each tongue means abuts a corresponding tongue means of the other third structural element along a curved contact surface.

Advantageously, said contact surface has an ogeeform profile, optionally a symmetrical ogiform profile. Preferably, the tenon means abut along respective curved contact surfaces.

Advantageously, said curved contact surfaces have an ogeeform profile, optionally a symmetrical ogeeform profile.

Preferably, the structural elements each comprise a substantially rigid, resiliently deformable material.

Advantageously, the structural elements each comprise a plastics material.

The structural elements may each comprise a moulding, for example an injection moulding.

Alternatively, the structural elements may comprise wood.

Alternatively, the structural elements may comprise a castable material, which may comprise a castable plastics material, or a metal.

The tenon means are preferably formed integrally with the respective structural elements.

The tongue means are preferably formed integrally with the respective structural elements.

Each structural element may be provided with means to connect further components of a structure thereto. According to a second aspect of the present invention, there is provided a component of a structure provided with at least one means to connect it to further components of the structure, said connecting means comprising either a tenon means or a pair of tongue means of a joint as described in the first aspect above.

Preferably, the structural component is provided with a plurality of said connecting means.

Advantageously, the structural element is provided with an even number of said connecting means.

The structural component may comprise a first elongate member having a first connecting means at a first end and a second connecting means at a second end remote from the first.

The first and second connecting means may both comprise said tenon means or both comprise said pairs of tongue means.

Alternatively, the first and second connecting means may comprise a pair of tongue means and a tenon means.

The structural component may comprise a second elongate member, extending transversely to the first, with respective connecting means at each of a first and a second, remote end thereof. The connecting means of the first elongate member may then each comprise said tenon means and the connecting means of the second elongate member may each comprise said pairs of tongue means.

According to a third aspect of the present invention, there is provided a structure comprising a plurality of joints as described in the first aspect above.

Preferably, the structure comprises storage means.

Advantageously, the structure comprises rack means, for example bottle or shoe rack means.

In a preferred embodiment, said structure comprises a plurality of substantially identical components.

According to a fourth aspect of the present invention, there is provided a structure comprising a plurality of structural components as described in the second aspect above.

Preferably, the structure comprises storage means, advantageously rack means, such as bottle or shoe rack means.

In a preferred embodiment, the structure comprises a plurality of substantially identical said components.

Said substantially identical components may be assembled in a modular fashion. According to a fifth aspect of the present invention, there is provided a kit of parts assemblable into a structure as described in either the third or fourth aspects above.

Embodiments of the present invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first joint embodying the present invention in separated form;

Figure 2 is a perspective view of the joint shown in Figure 1, in partially assembled form;

Figure 3 is a perspective view of the joint shown in Figure 1, in assembled form;

Figure 4 is a scrap plan view of a central potion of the joint shown in Figure 1, in assembled form;

Figures 5a and 5b are perspective views of components of the joint shown in Figure

1, viewed from an opposite side;

Figures 6a and 6b are side elevations of the respective components shown in Figures

5a and 5b;

Figure 7 is a perspective view of a second joint embodying the present invention, in assembled form;

Figure 8 is a perspective view of the joint shown in Figure 7, viewed from an opposite side;

Figure 9 is a perspective view of a third joint embodying the present invention, in assembled form;

Figure 10 is a frontal elevation of a first structural component embodying the present invention; Figure 11 is a frontal elevation of a first structure embodying the invention, comprising a plurality of components as shown in Figure 10;

Figure 12 is a schematic perspective view of a bottle rack embodying the present invention, comprising two structures as shown in Figure 11 ;

Figures 13a to 13c are side elevations of a respective second, third and fourth structural component embodying the present invention; and

Figure 14 is a perspective view of a fourth joint embodying the present invention, in separated form.

Turning now to the Figures, and to Figure 1 in particular, a first joint 1 is designed to connect securely two first struts 2 and two second struts 3, with the two first struts 2 extending substantially collinearly and the two second struts 3 extending substantially collinearly each with the other and substantially orthogonally to the two first struts 2.

Each first strut 2 is provided with a pair of mortise-defining tongues 4 extending outwardly from one end. Each tongue 4 extends flush with a surface of the respective strut 2, and the tongues 4 of each pair extend parallelly, each to the other, spaced by a gap 5.

Each second strut 3 is provided with a part-tenon 6 extending outwardly from one end. The part-tenons 6 have a thickness corresponding substantially to that of the gap 5 between the tongues 4 of the first struts 2, and each part-tenon 6 extends substantially in line with a midline of the respective second strut 3.

As shown in Figure 2, the respective pairs of tongues 4 may be brought into contact, defining between them a mortise slot 7. The mortise slot 7 has a constant elongate rectangular cross- section, and extends all the way through the conjoined first struts 2. The tongues 4 are so shaped that corresponding tongues 4 fit exactly along a seam 8, forming continuous opposing walls of the mortise slot 7. In the particular joint 1 shown, the pairs of tongues 4 on each first strut 2 are identically shaped, each here ending in a contact surface with an ogeeform profile and producing a seam 8 shaped as an ogee or shallow "S".

Clearly, a single body with a mortise slot 7 formed therethrough may be substituted for the two conjoined first struts 2, although this would lessen the versatility of the joint 1.

As shown in Figure 3, the part-tenons 6 may be inserted into the mortise slot 7 from opposite ends thereof, connecting the second struts 3 to the conjoined first struts 2. As in the case of the tongues 4, the part-tenons 6 are so shaped that they fit together exactly within the mortise slot 7. Again, it is preferable that the part-tenons 6 be identically shaped, each here ending in an ogiform contact surface. Thus, as shown in Figure 4, the two part-tenons 6 (here represented by dashed lines) together fill the mortise slot 7 completely.

Various arrangements are envisaged to hold the joint 1 together once assembled. For example, a layer of adhesive on each contact surface of the mortise-defining tongues 4 and part-tenons 6 would hold the joint 1 together securely, particularly given the large contact area between the part-tenons 6 and the tongues 4 forming walls of the mortise slot 7.

However, such an arrangement would not allow the joint 1 to be disassembled with any ease. There are many structures which can be assembled in several different configurations (for example, bottle racks) and one might wish to reconfigure these structures. One might also desire to disassemble a structure for storage or transport, then rapidly reassemble it. Figures 5a and 5b show features of the joint 1 (which were omitted from Figures 1 to 5 for the sake of clarity), that allow it to be assembled securely, then disassembled at will, on multiple occasions, without loss of fastening strength. One of the pair of mortise-defining tongues 4 extending from each first strut 2 has two apertures 9 extending therethrough, one adjacent a base of the tongue 4 and one adjacent its tip. The part-tenon 6 of each second strut 3 is provided with two studs 10, one adjacent a base of the part-tenon 6 and one adjacent its tip. When the tongues 4 are conjoined to define the mortise slot 7 and the part-tenons 6 are inserted transversely thereinto, the studs 10 engage with corresponding apertures 9 to lock the joint 1 together. The studs 10 on each part-tenon 6 engage with an aperture 9 adjacent the base of one tongue 4 and an aperture 9 adjacent the tip of the other tongue 4 conjoined therewith. Thus, each part-tenon 6 is fastened to each apertured tongue 4 and vice-versa.

As shown in Figure 6a, the apertures 9 most conveniently extend completely through the respective tongue 4, although it would equally be possible to employ recesses opening only to the gap 5 between the tongues 4, depending for example on convenience of manufacture. As shown in Figure 6b, the studs 10 preferably have a shallow frustoconical form, the sloping surface of which eases the passage of the part-tenon 6 and the studs 10 into the gap 5 between the tongues 4, and helps to locate and centre the studs 10 within the apertures 9 for a more positive fit.

This fastening arrangement is particularly suitable for joints 1 between struts 2, 3 or the like made from strong, resiliently deformable materials, such as plastics materials. This allows the studs 10 to displace the tongues 4 resiliently outwardly as the part-tenon 6 is inserted or withdrawn from the gap 5. The components of the joint 1 shown are also particularly suited for production by injection moulding.

When using other materials of construction, the particular ogiform shape of the tongues 4 and part-tenons 6 of the first joint 1 may not be as convenient to produce, and a second joint 11, as shown in Figure 7, may be preferred. In this, the mortise-defining tongues 4 (and the part- tenons 6, not visible in this view) have a simple rectangular profile, giving a seam 8 between corresponding tongues 4 comprising only straight lines. The mortise slot 7 has exactly the same shape as in the first joint 1, and the rectangular part-tenons 6 fill the mortise slot 7 side- by-side. While this shape of tongue 4 may be less aesthetically attractive than those of the first joint 1, it is probably easier to produce in materials such as wood.

As in the case of the first joint 1, the second joint 11 can be produced with engageable studs 10 and apertures 9 to fasten its components together (see Figure 8 for the resulting appearance of the second joint 11 when viewed from a direction opposite to that of Figure 7). However, where a less resilient material, (such as most forms of wood), is to be used, screws, nails, dowels or the like may be used to fasten the joint 11 together. For example, aligned apertures 9 could be bored through both tongues 4 of each pair and through the two part- tenons 6, and a dowel of appropriate diameter inserted therethrough, with or without the addition of adhesive. Each opposite face of the second joint 11 would then display four apertures 9 arranged in a square, as shown in Figure 8.

It is also envisaged that for materials which do not allow for easy resilient deformation of the tongues 4, e.g. metals, the studs 10 could be resiliently mounted to the respective part-tenons 6, e.g. being spring-mounted within a bore, from which they will protrude once aligned with a respective aperture 9.

It is equally possible for the studs 10 to be located on one tongue 4, extending into the gap 5, and for the apertures 9 (or recesses) to extend through (or into) the part-tenons 6. Many other detachable or permanent locking arrangements between the tongues 4 and part-tenons 6 are possible, although in all cases it is desirable that each part-tenon 6 is directly fastened to each pair of tongues 4 and vice versa.

A third joint 12 is shown in Figure 9, in which the tongues 4 (and the part-tenons 6, not visible) are shaped to abut with their counterparts along a simple straight seam 8. Thus, each tongue 4 only extends halfway across the mortise slot 7 defined thereby, and each part-tenon 6 only extends halfway through the mortise slot 7. While this third joint 12 may be adequate in some applications, it is probably not as strong and reliable as the first and second joints 1, 11 in which the tongues 4 and part-tenons 6 are significantly longer.

An example of a structural component that may be fastened together using the first joint 1 (or possibly the second 11) is shown in Figure 10. A cruciform component 13 comprises two orthogonal elongate bars 14 crossing at their respective midpoints. A first bar 14 is provided with a pair of mortise-defining tongues 4 extending from each remote end, and the second of the bars 14 is provided with a part-tenon 6 extending from each remote end. The tongues 4 and part-tenons 6 have ogiform profiles, as for the first joint 1 above. Four such cruciform components 13 can thus be linked together, using the mortise-defining tongues 4 of two of the cruciform components 13 and the part-tenons 6 of the other two. Such a cruciform component 13 may be produced as a single plastics injection moulding. A lattice structure 15 can thus be built up, as shown in Figure 11, using any desired number of cruciform components 13, held together by joints 1 linking four neighbouring components 13. Partial joints 16 at a. periphery of the lattice structure 15 are held loosely together by engaging studs 10 and apertures 9, providing an additional degree of stability. They may also act as feet by which the lattice structure 15 may be rested on a supporting surface 17.

As well as the orientation shown, in which the lattice structure 15 defines a plurality of diamond-shaped windows 18, it may also be oriented with the bars 14 of each cruciform component 13 aligned vertically and horizontally, if preferred.

One application of the rapidly-assemblable lattice structure 15 is in a bottle rack 19, as represented schematically in Figure 12. This comprises two congruent upright lattice structures 15 connected by a plurality of horizontally-extending steel rods 20 (sockets to receive the rods 20 are moulded into each cruciform component 13, but are omitted from the Figures for clarity). The rack 19 is so dimensioned that a bottle of wine, for example, may be inserted through a window 18 of one lattice 15 and supported on two neighbouring horizontal rods 20. The modular nature of the lattices 15 allows the rack 19 to be extended, reconfigured or even reduced in size as desired, and the stability of the joints 1 allows a relatively lightweight rack 19 to support a large number of bottles in safety.

While the cruciform components 13 are shown as simple cross shapes, a designer is at liberty to create any desired shape of body as long as it is provided with four orthogonally outwardly extending connecting features 4, 6 to link it to other components 13 in a structure. The joints 1, 11, 12 shown may also be constructed from components having only two connecting features 4, 6 as shown in Figures 13a to 13c. A first strut component 21 comprises a single elongate member having a part-tenon 6 extending from each remote end (here, a rectangular part-tenon 6 from the second joint 11 is shown, for simplicity). A second strut component 22 comprises a single elongate member with a pair of mortise-defining tongues 4 extending from each remote end. Thus, two first strut components 21 and two second strut components 22 may be brought together to form a joint 11, and each strut component 21, 22 may participate in a further such joint 11 at its respective end remote therefrom. Lattices 15 similar to that shown in Figure 11 may thus be built up; they will comprise twice as many joints, but the added versatility may be an advantage in some applications.

Indeed, as shown in Figure 13c, a third strut component 23, having a pair of mortise-defining tongues 4 extending from a first end of an elongate member and a part-tenon 6 extending from a second end remote from the first, may be all that is required to construct a lattice 15 or similar structure. This reduces the number of different structural components to be produced, although some extra care will be required during assembly to ensure that two part-tenons 6 and two pairs of tongues 4 are offered up to each joint 11 to be made.

The joints 1, 11, 12 shown may possibly be used in other structures, not necessarily forming lattices 15. One example is shown in Figure 14, where a beam 24 is provided with three mortise slots 7 extending therethrough. Two panels 25 are each provided along one edge with three correspondingly-spaced part-tenons 6. These are inserted into the respective mortise slots 7 from opposite sides of the beam 24, filling the mortise slots 7, and forming three joints 11 which are locked in place by any of the arrangements described above. The panels 25 are thus securely mounted to the beam 24.

The joints 1, 11, 12 are thus highly versatile, and it is envisaged that they may be applied to a wide variety of different structures in addition to those described above.

Claims

1. A joining means adapted to connect a plurality of structural elements, said joining means comprising first structural element means defining mortise slot means, two second structural elements each provided with respective tenon means insertable into said mortise slot means from opposite ends thereof and so conformably shaped as together substantially to fill the mortise slot means, and means to retain each tenon means within the mortise slot means.

2. A joining means as claimed in claim 1, wherein each tenon means is adapted to extend substantially through the mortise slot means.

3. A joining means as claimed in either claim 1 or claim 2, wherein the retaining means comprises detent means.

4. A joining means as claimed in claim 3, wherein said detent means comprises stud means located on either one of a tenon means and the first structural element means, and cooperable recess means located on the other of said tenon means and the first structural element means.

5. A joining means as claimed in any one of the preceding claims, wherein the first structural element means comprises two third structural elements, so conformably shaped as to be assemblable to define the mortise slot means therebetween.

6. A joining means as claimed in claim 5, wherein said two third structural elements are provided with means to retain them so assembled, optionally comprising said means to retain the tenon means.

7. A joining means as claimed in claim 6, wherein the retaining means secures each tenon means to each of the third structural elements.

8. A joining means as claimed in any one of claims 4 to 7, wherein the retaining means comprises stud means located on each tenon means so as to be cooperable with respective recess means located on each third structural element.

9. A joining means as claimed in any one of claims 4 to 8, wherein each third structural element is provided with a pair of substantially parallelly-extending spaced-apart tongue means, each cooperable with a corresponding tongue means of the other third structural element to form a respective wall of the mortise slot means, optionally a respective continuous wall.

10. A joining means as claimed in claim 9, wherein each tongue means is adapted to extend substantially across an entire width of the mortise slot means.

11. A component of a structure provided with at least one means to connect it to further components of the structure, said connecting means comprising either a tenon means or a pair of tongue means of a joining means as claimed in any one of the preceding claims.

12. A structural component as claimed in claim 11, provided with a plurality of said connecting means, optionally an even number thereof.

13. A structural component as claimed in either claim 11 or claim 12, comprising a first elongate member having a first connecting means at a first end and a second connecting means at a second end remote from the first.

14. A structural component as claimed in claim 13, comprising a second elongate member, extending transversely to the first, with respective connecting means at each of a first end and a second, remote end thereof.

15. A structure comprising a plurality of joining means as claimed in any one of claims 1 to 10.

16. A structure comprising a plurality of structural components as claimed in any one of claims 11 to 14.

17. A structure as claimed in either claim 15 or claim 16, comprising storage means, optionally rack means, such as bottle or shoe rack means.

18. A structure as claimed in any one of claims 15 to 17, comprising a plurality of substantially identical components.

19. A kit of parts adapted to be assembled into a structure as claimed in any one of claims 15 to 18.