GB2223688A - Toy and other construction systems - Google Patents

Abstract

A construction system employs connectors for connecting together members which have openings along their edges. The members may be panels of corrugated cardboard or of plastics material having outer planar layers joined by transverse spaced walls to form the edge openings. The connectors have spigots (e.g. of D-section) which deform the openings when inserted. A variety of connectors is employed. Some connectors provide flexible hinges. Others provide bearings for wheel-bearing axles.

Description

CONSTRUCTION SYSTEMS This invention relates to construction systems, and more particularly to connectors for joining together separate members, at least one of the members having an opening within which a connector can engage.

Most structures include discrete members which are connected together by means of welds, adhesives or connectors. There have been myriad proposals for connectors such as nuts and bolts, dowels or pegs which are retained within openings in the members being joined.

There have also been various proposals for construction systems in which the various components are reusable.

Typical examples are bricks which interlock by means of projecting studs.

It is also customary in schools to construct models from sheet material such as cardboard or fluted plastics material which has a construction similar to corrugated cardboard and comprises upper and lower laminar faces which are joined together by transverse, spaced walls so that along edges of the material which run perpendicular to the walls a plurality of adjacent openings are provided. In order to construct models from such laminar materials adhesive is used. Where models are to be constructed from fluted plastics material, it is necessary to use a hot melt adhesive. This requires close supervision if models are to be constructed by small children. Moreover, the models cannot be broken down and the components reused where adhesive has been employed.

The type of model which can be constructed from cardboard or fluted plastics material members and adhesive is also restricted. For example, it is difficult to construct a model vehicle using such materials.

The present invention addresses the technical problems of providing a construction system which is safe in use, allows for the reuse of the components, and facilitates the construction of elaborate models.

The construction system of the present invention employs connectors which have end portions shaped to be received by means of an interference fit in openings provided at the edges of construction members. Preferably at least some of the construction members are sheets of fluted plastics material as defined above.

Such a system is advantageous in that, if the walls of the openings are sufficiently elastic, both the connectors and the construction members may be reused.

In any event, the connectors can usually be reused. If the other construction members are cut from relatively cheap material, such as cardboard or fluted plastics material, it is not a serious disadvantage if these components cannot be reused. It will be appreciated that adhesive is not necessary for the construction of elaborate models using this system.

In a preferred type of connector means are provided to limit the extent of insertion of an end portion of the connector into an opening. This facilitates the use of the connectors by small children.

A construction system preferably provides a variety of different types of connector each having at least one end portion for insertion into an opening so that a wide variety of joints may be made between the construction members.

A construction system embodying the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure l(a) is a plan view of a first type of connector; Figure l(b) is a sectional view taken on line A-A of Figure 1(a); Figure 2(a) and 2(b) are sectional views for explaining the interference fit between the connectors and members; Figure 3(a) is a plan view showing a further type of connector.

Figure 4(a) is a plan view showing another type of connector; Figure 4(b) is a sectional view taken on line C-C of Figure 4(a); Figure 5(a) is a plan view showing a further type of connector; Figure 5(b) is a sectional view taken on line D-D of Figure 5(a); Figure 6(a) is a plan view of another type of connector; Figure 6(b) is a sectional view taken on line E-E of Figure 6(a); Figure 7(a) to 7(e) illustrate the connectors in use; and Figure 8 shows a structure built using the described construction system.

Although it is envisaged that the connectors to be described may be used for connecting any members with suitable openings, in the fields of construction, packaging or the like, it is thought that the system will be particularly useful in the field of constructional toys or educational models.

The system will therefore be described primarily with reference to its use in connecting together construction members which are cut from sheets of fluted plastics material either to one another or to other components such as wheel axles in order to produce elaborate models of the type illustrated in Figure 8.

Referring to Figures l(a) and l(b) of the drawings, a first type of connector 10 includes an elongate body 12 having a flat face 14 and a part-cylindrical face 16 defining a generally "D"-shaped cross section. The ends of the body 12 are part-spherical with a radius similar to that of the part-cylindrical face 16.

Lugs 18 project transversely from the sides of the body 12 at the mid-point thereof and split the body into two identical end portions 20 and 22. The lugs 18 share the D-shaped cross section and rounded ends of the body 12 but are of considerably thinner section.

The connector 10 is preferably made of an injectionmoulded plastics material such as polypropylene. The preferred D-shaped cross section gives good demould characteristics, and also gives low tooling costs because the moulding die can be produced with standard roundnosed cutters.

In use, one end portion 20 of the connector 10 is pushed into an opening in a member and the other end portion 22 is pushed into an opening in another member, whereby the members may be connected by the end portions 20 and 22 retained therein. The lugs 18 serve to prevent the end portions 20, 22 being pushed in so far as to be difficult to remove. The rounded ends of the end portions 20,22 facilitate insertion into the openings.

The cross-sections of the end portions 20,22 are shaped and dimensioned such that deformation of the opening must occur before the opening can accept the end portion.

This deformation ensures that the portions are firmly held within the openings by an interference fit with the walls of the openings. Nevertheless, the surfaces of the end portions and/or the walls of the openings may be roughened, ridged or dimpled to enhance their grip upon one another.

The basic dimensional characteristic of end portions 20,22 is that they have a major diameter which is larger than the width of the undeformed opening along a given, first axis. This ensures that deformation must occur if the portion is to enter the opening with the major diameter aligned along that axis. Generally, the deformation will take the form of elongation of the opening along the line of the major diameter.

A further characteristic of the end portions 20,22 is that they have a minor diameter transverse to the major diameter which is less than the width of the undeformed opening along a second axis transverse to the first axis.

This ensures that the walls of the opening have room to move towards one another on the second axis. Therefore the opening can contract along the second axis in response to elongation along the first axis.

Accordingly, the opening can maintain a substantially constant circumference i.e. the walls of the opening need not stretch to any great degree. Instead, the deformation of the opening is mainly effected by bending off the walls.

Figures 2(a) and 2(b) respectively illustrate the shape of an opening before and after an end portion 20,22 of a connector is inserted therein. Figure 2(b) illustrates the deformation of the opening 23 along the first axis X and the second axis Y in response to insertion of the portion 20,22.

The characteristics of the end portions 20,22 are such that the connector 10 can be fixed in a number of shapes and sizes of opening. This is because bending of -the walls of the opening can allow for considerable discrepancies in size and shape while still providing grip. Conversely, if stretching of the walls was relied upon, very close dimensional tolerances between the connector 10 and the opening would be required.

A further advantage of bending rather than stretching the walls of the opening is that the elastic limit of the wall material is less likely to be exceeded, and therefore the walls are more likely to revert to near their original shape once the connector is removed. As will be clear, this attribute may be particularly important in the field of constructional toys, where connectors and members are desirably re-usable.

Other types of connector are illustrated in Figures 3,4,5 and 6. These connectors all share the same type of end portion for reception in an opening. The connectors have various shapes to facilitate the construction of various types of joints.

In the connector 24 shown in Figures 3(a) and 3(b), each end portion 20,22 has a pair of lugs 18 and the end portions are connected by a thin flexible link 26. The connector 24 may therefore act as a hinge between two sheets 25 as shown in Figure 7(b), or may be used to fix the sheets at any angle to one another.

The connector 28 shown in Figure 4(a) and 4(b) has its two end portions 20 and 22 set at right angles to one another. Using this connector, two sheets 25 can be set at right angles to one another as shown in Figure 7(d).

The connector 28 illustrated does not have lugs 18 as the setting of the end portions at right angles to one another effectively limits the extent to which each-end portion can be inserted into an opening.

Figure 5(a) and 5(b) show a connector 30 which is of generally U-shape, the two end portions 20 and 22 lying beside and parallel to one another. The end portions 20 and 22 are connected by a transverse intermediate portion 32. This connector serves to link two adjacent sheets 25 as shown in Figure 7(c). Again, lugs could be provided on connector 30 if desired but are not essential as the intermediate portion 32 acts to limit the extent of insertion into an opening.

Figure 6(a) and 6(b) illustrate a connector 34 having a D-section ring 36 connecting the end portions 20 and 22.

The ring 36 can be used as a bearing for an axle member 38 or a fixed rod as shown in Figure 7(e). An incidental benefit of the preferred D-section is that alignment of the axle is not critical for free running. In the illustrated connector, the end portions 20,22 are aligned and diametrically opposed about the ring 36. However, it will be clear that the portions could be set at say 120 degrees to one another, and there could be only one or more than two end portions connected to the ring if desired. Lugs 18 could also be provided, although the ring itself will limit the extent of insertion of the end portions.

Figure 8 shows a construction toy or educational model constructed in the form of a vehicle fitted with wheels 40. This drawing illustrates potential applications of the various connectors.

It will be appreciated that many variations are possible.

For instance, although a D-section is preferred, any cross-sectional shape (such as triangular or rectangular) could be employed.

Claims (11)

1. A construction system comprising a plurality of connectors each having at least one end portion shaped so as to be received by means of an interference fit in an elastic-wall opening defined in an edge of a construction member.

2. A construction system according to claim 1, wherein at least one dimension of the end portion of each connector is greater than a corresponding dimension of an opening in which it is to fit in order that the connector may not be fitted into the opening without causing deformation of the walls thereof.

3. A construction system according to claim 1 or 2, wherein each end portion has a D-shaped cross section.

4. A connector for use in a construction system, comprising at least one end portion and means for limiting the extent of insertion of said end portion into an opening.

5. A connector as claimed in claim 4, having two end portions axially aligned with one another, and wherein the limiting means comprises at least one lug extending transversely from the connector intermediate the end portions.

6. A connector as claimed in claims 4 or 5, wherein two end portions are joined by a flexible link.

7. A connector as claimed in claim 4 or 5, wherein two end portions are inclined at an angle to one another.

8. A connector as claimed in claim 4 or 5, wherein two end portions are connected so as to be spaced and parallel to one another.

9. A connector as claimed in claim 4 or 5, wherein a ring is connected to at least one end portion.

10. A construction system substantially as herein described with reference to the accompanying drawings.

11. Any of the connectors substantially as herein described with reference to any of Figures 1,3,4,5 and 6.