GB2210130A

GB2210130A - A joint

Info

Publication number: GB2210130A
Application number: GB8821958A
Authority: GB
Inventors: Reginald Valentine Wilks
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-09-18
Filing date: 1988-09-19
Publication date: 1989-06-01
Anticipated expiration: 2008-09-19
Also published as: GB2210130B; GB8821958D0

Abstract

A joint comprises two component parts (10, 12) one fixed to each of the members to be jointed. Each component part includes an end portion longitudinally split at an interface (14) on a plane passing through the longitudinal axis of the joint. Each component part has a projection (16) and corresponding recess (18) symmetrically located on either side of the longitudinal interface, which has at least one groove (22) and corresponding tongue (20) mutually locating when the two component parts are fitted together. Magnets at the bottom of recesses (18) attract the projections (16) to provide a weak fixing means for the joint. A stronger fixing means can be provided, eg in the form of screw 32 acting on plate 30. <IMAGE>

Description

Joint lihis invention relates to a joint enabling rapid assembly and disassembly of items such as table legs, frame members and the like.

table legs are commonly fixed to the table top they support in a semi-permanent manner. In many situations, especially for use at exhibitions and the like, it would be convenient for the table legs to be capable of rapid assembly and disassembly for transportation and storage of the table.

Ihe joint according to the invention seeks to provide a simple convenient means of enabling members to be rapidly assembled and disassembled.

According to the present invention, there is provided a joint which comprises two component parts, one to be fixed to each of the members to be joined, each component part comprising an end portion longitudinally split at an interface on a plane passing through the longitudinal axis of the joint and having a projection and corresponding recess symmetrically located on either side of the longitudinal interface, the longitudinal interface being provided with at least one groove and corresponding tongue which mutually locate when the two component parts are fitted together.

lhe joint according to the invention is preferably provided with a first, weaker fixing means and, optionally, a second, stronger fixing means. Conveniently, the first fixing means is magnetic. For example, the projection may be in the form of a ferro-magnetic metallic dowel and a permanent magnet may be located within the corresponding recess so that when the two component parts are inter-engaged the dowel is attracted by the magnet and the joint therefore held in place.

ihe second, stronger, fixing may take a variety of forms. In its simplest form a transverse pin, bolt or the like may be passed through the component parts fixing them together. A preferred form of second fixing means comprises a locking member held in a recess in the interface of at least one of the component parts, which member is operable externally of the component part, for example, by means of an external screw passing through to the locking member. Ihe locking member may, for example, be a captive nut or bush, or a plate which projects into a corresponding recess in the other component part when the other two are engaged.

lhe joints may be made from any suitable material such as wood, plastics material, or metal but it is envisaged that a moulded plastics material or alloy would be preferred.

lhe invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a longitudinal axial section through a component part of a joint according to the invention; Figure 2 is an exploded perspective view of the joint of the invention; Figure 3 is an exploded perspective vie of a joint according to the invention in the form of a body of rectangular section; Figures 4 and 5 are side elevations of the components in Figure 3; Figure 6 is a section along the line FI - I in Figures 4 and 5; and Figure 7 is an exploded perspective view of another embodiment of the invention.

Referring to the drawings, a joint is formed of two component parts 10,12 which matingly inter-engage. Each component part 10,12 is fixed in a permanent or semi-permanent manner to one of the members to be joined, for example, a table leg and the underneath of a table top. As illustrated the two component parts are generally of circular cross-section but this is by no means essential; other cross-sectional shapes, for example, square, can be equally useful. One end of each of the component parts 10,12 is split on a plane passing through the longitudinal axis to provide a longitudinal interface 14.Symmetrically disposed on either side of the interface 14 are projections in the form of ferro-magnetic dowels 16 and corresponding recesses 18. One component part 10 or 12 is provided with longitudinal tongues 20 which cooperate with corresponding grooves 22 in the other component part 12 or 10. lhe end faces 24 carrying the dowel 16 may be angled as shown, in which case the angles on the component parts 10 and 12 will be complementary; alternatively they may be square. Behind each of the recesses 1 & is located a permanent magnet 26.

fihe interfaces 14 contain recesses 26 one of which receives a locking plate 30 which in turn receives an operating screw 32 whose head is accessible externally of the joint.

In use, one of the component parts 10,12 is attached to one of the members to be joined and the other component part is attached to the other member. lhe two component parts are brought together so that the dowel 16 on the component part 10 mates with the recess 18 and the component part 12 and vice versa. longues 20 locate in the grooves 22 in order to give a more positive location. lhe dowels 16, being of a ferro-magnetic material, are attracted by the magnets 26 and thus a first, relatively weak, fixing is obtained. lhis fixing will normally be sufficient where, for example, a table top is being fixed to table legs. lhe weight of the table top tends to hold the joint in place while the magnetic attraction between the magnet 26 and dowels 16 is sufficient to ensure that the legs do not fall out if the table is lifted or moved.

However, in cases where a greater joint strength is required, the locked plate 30 can be employed. Ihis is operated by means of the external screw 32 which is turned so as to move the plate out of the recess 28 in the component part 12 towards the recess 28 and the component part 10 thereby preventing the two component parts from being slid apart.

Where an even greater degree of security is provided the locking plate can be replaced by a bolt or the like passing through the two component parts 10,12 at the expense of slightly longer fixing and dismantling time.

If preferred one tongue 20 and one groove 22 can be in one component part 10 and the other tongue 20 and groove 22 in the other component part 12.

Figures 3 to 6 (in which like parts are denoted by like reference numerals) show the joint according to the invention in the form of a body of square or rectangular cross section, instead of round as shown in Figures 1 and 2. In Figure 7 (again like parts being denoted by like reference numerals), the main plane of the longitudinal interface 14 is approximately diagonal to the transverse cross-section of the body. keak tapered edges are avoided, and the strength increased, by forming short faces 32 at the edges thereof, approximately normal to the main plane.

lhe joint according to the invention may be used in many situations and is particularly useful where items need to be assembled quickly and equally quickly disassembled, for example at exhibitions. Thus it may be used for racks, display stands and the like as well as for fixing legs to items of furniture such as tables.

The joint of the invention is simple to use, rapidly assembled and rapidly disassembled, and, with two levels of fixing., provides a simple and useful method of fixing many items where rapid assembly and disassembly is required.

Claims

CLAIMS:

1. A joint which comprises two component parts, one to be fixed to each of the members to be joined, each component part comprising an end portion longitudinally split at an interface on a plane passing through the longitudinal axis of the joint and having a projection and corresponding recess symmetrically located on either side of the longitudinal interface, the longitudinal interface being provided with at least one groove and corresponding tongue which mutually locate when the two component parts are fitted together.

2. A joint according to claim 1, including a first, weaker fixing means and, optionally, a second stronger fixing means.

3. A joint according to claim 2, in which the first fixing means is magnetic.

4. A joint according to claim 3, in which the projection is in the form of a ferro-magnetic dowel.

5. A joint according to claim 4, in which a permanent magnet is located within the corresponding recess so that when the two component parts are inter-engaged the dowel is attracted by the magnet and the joint therefore held in place.

6. A joint according to any of claims 2 to 5, in which the second, stronger, fixing comprises a transverse pin, bolt or the like passed through the component parts fixing them together.

7 A joint according to any of claims 2 to 5, in which the second fixing means comprises a locking member retained in a recess in the interface of at least one of the component parts.

8. A joint according to claim 7 in which the locking member is retained in said recess by retaining means which is operable externally of the component part.

9 A joint according to claim 8, in which said retaining means comprises an externally operable screw passing through to the locking member so as to project into E corresponding recess in the other component part when the two component parts are engaged.

10. A joint according to any of claims 1 to 9, which is of square or rectangular cross-section and in which the longitudinal interface includes a main plane extending approximately between diagonally opposite edges of the joint.

11. A joint according to claim 10, in which the longitudinal interface includes a longitudinal subsidiary plane at each end of the main plane and approximately normal thereto.

12. A joint according to any of claims 1 to 5, in which the longitudinal interface of each component part includes a recess, one of said recesses holding a locking member movable partly into the other of said recesses, after the component parts have been assembled by relative longitudinal motion thereof, to lock the component parts together.

13. A joint constructed and arranged and adapted to operate substantially as described herein and as shown in the accompanying drawings.

14. A table incorporating a joint according to any preceding claim.