GB2225078A

GB2225078A - Joints for metal-flamed buildings

Info

Publication number: GB2225078A
Application number: GB8922961A
Authority: GB
Inventors: John Keen
Original assignee: Am & S Europ
Current assignee: Am & S Europ
Priority date: 1988-11-12
Filing date: 1989-10-12
Publication date: 1990-05-23
Anticipated expiration: 2009-10-12
Also published as: GB8826517D0; GB2225078B; GB8922961D0

Abstract

A sprung tab and slot system for a steel framed building has resilient tabs 3 formed in the sidewalls of a channel- section member, which tabs are sprung into slots 4 of a complementary channel or box-section member. <IMAGE>

Description

Improvements in or relating to Joints for Metal-Framed Buildings This invention relates to frameworks which form the structural basis of metal-framed buildings.

It is already known to construct such frameworks from metal members which are of generally channel-shaped section and wherein tabs passing through slots are used to join these members together.

A typical example of such a construction is shown in British patent specification 1,468,190 published 23rd March 1977, in which the tabs are formed at the end of the members and inserted into slots and then bent over or twisted to produce a joint.

UK patent specification 2,119889A describes a jointing system with metal members of channel-shaped section joined at right-angles wherein slots in the first channel member can be engaged with or disengaged from tabs in a second channel member by springing the first channel's walls apart, without bending the tabs, so that the channel members can be locked together at right angles.

Such a system results in a firm and rigid joint but is intended primarily for the connection of parts where the end of the first channel member is inserted into the open channel of the second member, in order to form a 'T' or corner junction as, for example; at the top or bottom junctions of channel-section wall-studs with horizontal channel sections forming the framework of a wall panel.

Other horizontal channel sections (noggings) are required in the framework of the panel and these are attached to the vertical 'studs' at mid-height (and also at other heights) in order both to provide restraint against (horizontal) deflections of the stud when subjected to vertical loading and also to provide plane surfaces to which lining boards and other fittings may be attached to the framework.

A second embodiment described and claimed in UK patent specification 2,119,889A involves inserting tabs through corresponding slots in adjacent channel sections and then twisting the tabs, within the channel section, to lock the two sections together. The tabtwisting operation can be difficult to perform due to inaccessability of the inserted tabs and the members are difficult to disconnect, if this is required at a later date.

We have now devised a method of connecting two channel-shaped or channel and box-shaped members rigidly at right angles which does not involve the springing apart of walls or the twisting or bending of tabs.

This invention consists in a structural framework for a building made up of metal members of channel-shaped and/or box-shaped cross section, wherein sidewalls of the channels are provided with tabs and sidewalls of the complementary channel or box-section are provided with slots, which are adapted to receive tabs of the complementary channels; characterized in that tabs formed in the channel-section walls are resilient and are formed with a raised shoulder portion between their free and attached ends, whereby the said tabs are resiliently deflected on passing through the slots, and the shoulders lock against edges of the corresponding slots when fully pushed home.

Preferably the tabs are formed by cutting away portions of the already-shouldered sidewalls of a resilient piece of metal of channelshaped section.

In a second aspect the invention consists in a piece of resilient metal of generally channel-shaped section wherein the channel sidewalls have outwardly bulging shoulders in proximity to the base/sidewall junction and a series of parallel-sided slots or notches cut out of the sidewalls so as to leave shouldered tabs at intervals along the length of the channel.

The tabs are forced into slots with the shoulder on the tab locking behind one edge (usually an inner horizontal edge) of the slot.

The invention will now be further described by reference t the accompanying 2 Figures of diagrammatic drawing, wherein: FIGURE 1 shows a tab and slot connecting system according to the invention, for connecting two channel sections at right angles, and FIGURE 2 shows a detail of the tab of FIGURE 1 and how it engages with the corresponding slot.

With reference to Figure 1 two channel-shaped metal members 1 and 2 are formed with tabs 3 and slots 4 respectively in their sidewalls, tabs 3 being formed by cutting notches out of the shouldered sidewalls 5 and 6 of the channel member 2.

As will be more clearly seen from Figure 2, the tab 3 is formed with a shouldered portion 3a, a flat end portion 3b and an intermediate sloping section 3c.

When the tongue 3b of tab 3 is inserted into slot 4 and it is pressed fully home the tab 3 is deflected downwardly due to the shoulder 3a encountering the upper horizontal surface of slot 4. Once the upper edge of the slot 4 has overridden the shoulder 3a the tab is locked in the slot by 3a locking behind the upper and inner horizontal edge of slot 4. In this way the tab is locked into the slot and the two channels are locked together.

The new invention may also be used, in the same way, where it is necessary to attach channel section noggings ar right-angles to the upper or lower faces of steel floor-joists of either channel or rectangular tube construction.

The channel section 1 may be produced by conventional roll-forming of sheet metal. The channel section 2 is produced by forming a channel-section from resilient sheet metal, with shouldered side walls and then cutting away parallel-sided notches or slots so as to leave the tabs 4 at intervals along the channel-walls as shown in Figure 1.

Although channel sections shouldered sidewalls are known it is believed that those with notches cut away to leave shouldered tabs are novel artefacts.

Claims

CLAIMS:

1. A structural framework for a building made up of metal members of channel-shaped and/or box-shaped cross section, wherein sidewalls of the channels are provided with tabs and sidewalls of the complementary channel or box-section are provided with slots, which are adapted to receive tabs of the complementary channels; characterized in that tabs formed in the channel-section walls are resilient and are formed with a raised shoulder portion between their free and attached ends, whereby the said tabs are resiliently deflected on passing through the slots, and the shoulders lock against edges of the corresponding slots when fully pushed home.

2. A framework as claimed in claim 1, wherein the tabs in the channel-sections are formed by cutting away portions of the already-shouldered sidewalls of a resilient piece of metal of channel-shaped section.

3. A framework as claimed in claims 1 or 2 wherein the shoulders of the tabs lockingly engage behind an inner horizontal edge of the corresponding slot.

4. A piece of resilient metal of generally channel-shaped section wherein the channel sidewalls have outwardly-bulging shoulders close to the base/sidewall junctions and a series of parallel-sided slots or notches cut out of the sidewalls, so as to leave shouldered tabs at spaced intervals along the length of the channel.

5. A structural framework for a building substantially as hereinbefore described with reference to Figures 1 and 2.

6. A channel shaped metal member with tabs formed in its sidewalls, substantially as hereinbefore described with reference to Figure 1.