A CONNECTOR FOR A FRAMEWORK STRUCTURE

Abstract: The connector is of one-piece construction and is for­ med of plastics material. It comprises a hub (10) and a plural­ ity of equi-angularly spaced projections (11, 12) of identical or substantially identical non-circular, e.g. triangular, cross-­ section extending outwardly from the hub. In one embodi­ ment there are two groups of projections (11 and 12), the projections (11) of one group alternating with the projec­ tions (12) of the other group. The projections (11) are rigidly joined to the hub so as to extend therefrom in a common plane and the projections (12) are joined to the hub by inte­ gral hinges (14). In an alternative embodiment all projec­ tions (11 and 12) are joined to the hub by integral hinges.

Description: "A CONNECTOR FOR A FRAMEWORK STRUCTURE" This invention relates to a connector of a type suitable for connecting together elongate members to form a framework structure which may be used, for example, as a display structure, and also relates to a frame work structure including such connectors. According to a first aspect of the invention, there is provided a connector formed of plastics material and comprising a hub and a plurality of equi-angularly spaced projections of identical or substantially identical non-circular cross-section extending outwardly from the hub wherein at least alternate projections are each joined to the hub by an integral plastics hinge. Preferably, there are two groups of projections, the projections of one group alternating with the projections of the other group, and the projections of the one group being rigidly joined to the hub so as to extend therefrom in a common plane while the projections of the other group are joined to the hub by integral hinges so that they can pivot from positions in which they lie parallel to said common plane to positions in which they are inclined to said common plane. Alternatively, all projections are joined to the hub by integral hinges so that they can pivot from positions in which they all lie in or are parallel to a single plane to positions in which they are each inclined to said single plane. Advantageously, each projection is of triangular or substantially triangular cross-section. In this case, if only alternate projections are joined to the hub by integral hinges the apices of the two groups of projections are conveniently arranged to face in opposite directions as considered with the hinged projections in positions in which they lie parallel to said common plane. However, if all projections are joined to the hub by integral hinges then conveniently the apices of all projections face in the same direction as considered with the projections in positions in which they all lie in or are parallel to said single plane. According to a second aspect of the invention, there is provided a framework structure comprising a plurality of connectors according to the first aspect of the invention and a plurality of elongate members, preferably but not necessarily having cylindrical or substantially cylindrical tubular ends at least, which have been push-fitted onto the projections. Preferablyat least the cylindrical ends of the elongate members are of deformable plastics material. The invention will now be more particularly described. by way of example, with reference to the accompanying drawings, in which: Figure 1 is a view of one end of one embodiment of a connector according to the first aspect of the invention, Figure 2 is a view of the other end of the connector shown in Figure 1, Figure 3 is a side view of the connector shown in Figures 1 and 2, and Figure 4 is a schematic view on a much reduced scale showing a plurality of elongate members connected together by connectors of Figures 1-3 to form a space frame. Referring firstly to Figures 1-3, the connector shown therein is formed of plastics material and comprises an octagonal hub 10. a first group of projections 11 and a second group of projections 12, each projection extending outwardly from the hub 10. The projections 11 and 12 are equiangularly spaced around an axis 13 of the hub and the projections 11 alternate with the projections 12. As shown all projections 11 and 12 are of triangular cross-section but they could be of other non-circular cross-section. The projections 11 are rigidly joined to the hub 10 so as to extend radially therefrom in a common plane normal to the axis 13. They also lie substantially between two parallel planes containing the two end faces, respectively, of the hub 10. The projections 12 are joined to the hub 10 by integral hinges 14 which permit the projections 12 to pivot from positions in which they are parallel to said common plane containing the projections 11 to positions in which they are inclined to said common plane on either side thereof. When, as shown in the drawings, the projections 12 are parallel to said common plane they lie substantially outside of the region between the two planes containing the two end faces, respectively, of the hub and their apices face in an opposite direction to the apices of the projections 11. A plurality of such connectors can be used to connect together elongate members in the form of deformable plastics tubes 15 (see Figure 4) of circular cross-section to form a space frame which may be used, for example, as a display stand. In order to locate a tube 15 on a projection 11, 2, an end of the tube is deformed, by hand pressure, is pushed over the projection and is then released. The inner wall of the tube is engaged by each of the three edges of the projection as an interference fit. If desired, the three edges of each projection may be less abrupt than shown; this being achieved by rounding off the edges or providing flats at the edges. In order to create the framework structure shown in Figure 4, the projections 12 are inclined at 45 to the axis 13. They may be inclined, however, at other angles to the axis 13 in order to make other structures. The hub 10 has a through hole 16 so that is may be mounted on a vertical support column to mount the framework structure at an elevated position. Instead of the tubes 15, solid rods, with deformable plastics sockets of circular cross-section at each end, could be used. If desired, the tubes 15 could be heat welded or secured by fasteners to the projections 11, 12 in order to provide a permanent installation, or if the tubes 15 and connectors 11, 12 are of the same material, the tubes may be secured to the projections of the connectors by adhesive. The connectors and tubes described above could be scaled down for use as a toy or an architect's model, and such a toy or model falls within the scope of the invention. In an alternative embodiment, all eight projections could be joined to the hub by integral hinges. In this case, however, it would be preferable for the apices of all projections to face in the same direction. Such a connector could be used to create, for example, a geodisic dome. Other modifications could be made without departing from the scope of the invention. For example, the connector could have more or less than eight projections.

Claims: CLAI: 1. A connector formed of plastics material and comprising a hub (10) and a plurality of equi-angularly spaced projections (11 and 12) of identical or substantially identical non-circular cross-section extending outwardly from the hub wherein at least alternate projections (12) are each joined to the hub by an integral plastics hinge (14). 2. The connector of Claim 1, wherein there are two groups of projections, the projections (11) of one group alternating with the projections (12) of the other group, and the projections (11) of the one group being rigidly joined to the hub (10) so as to extend therefrom in a common plane while the projections (12) of the other group are joined to the hub by integral hinges (14) so that they can pivot from positions in which they lie parallel to said common plane to positions in which they are inclined to one side of said common plane. 3. The connector of Claim 2, wherein the projections (11) of the one group lie substantially between two parallel planes containing opposite end faces, respectively, of the hub (10) and the projections (12) of the other group lie substantially outside of the region between said two planes. 4. The connector of claim 2 or claim 3, wherein there is at least four projections in each group (11,12). 5. The connector of Claim 1, wherein all projections (11 and 12) are joined to the hub (10) by integral hinges (14) so that they can pivot from positions in which they all lie in or are parallel to a single plane to positions in which they are each inclined to said single plane. 6. The connector of anyone of the preceding Claims, wherein each projection (11 and 12) is of triangular or substantially triangular cross-section. 7. The connector of Claim 6 when dependent on any one of Claims 2-4, wherein the apices of the two groups of projections (11 and 12) are arranged to face in opposite directions as considered with the hinged projections (12) in positions in which they lie parallel to said common plane. 8. The connector of Claim 6 when dependent on Claim 5, wherein the apices of all projections (11 and 12) face in the same direction as considered with the projections in positions in which they all lie in or are parallel to said single plane. 9. The connector of anyone of the preceding Claims, wherein the hub (10) has a hole (16) extending axially therethrough. 10. A framework structure comprising a plurality of connectors as set forth in anyone of the preceding Claims and a plurality of elongate members (15) which have been push-fitted onto the projections (11 and 12). 11. The framework structure of claim 10, wherein the elongate members (15) have cylindrical or substantially cylindrical tubular ends at least. 12. The framework structure of Claim 11, wherein at least the cylindrical ends of the elongate members (15) are of deformable plastics material.

Inventors: STEPHENSON, COLIN JOHN STEWART
Applicants: STEPHENSON, COLIN JOHN STEWART
Application year: 1985
Main classification: F16B7
IPC codes: F16B7, E04B1, A63H33