WO1992001843A1

WO1992001843A1 - Expansion joint

Info

Publication number: WO1992001843A1
Application number: PCT/GB1991/001166
Authority: WO
Inventors: Colin Ian Campbell
Original assignee: Vexcolt (Uk) Limited
Priority date: 1990-07-23
Filing date: 1991-07-15
Publication date: 1992-02-06
Also published as: AU8231091A

Abstract

A joint allowing expansion at a gap between exposed surfaces of two adjacent parts of a building, the joint comprises: two lateral supports (1, 2) spaced in use at the gap (G), each lateral support (1, 2) being adapted to be set along an edge of the exposed surface (F) of its part of the building at the gap (G); each lateral support (1, 2) having an outer surface (21, 22), which surface (21, 22), when the lateral support (1, 2) is set in its use position, inclines shallowly inwardly with respect to the exposed surface (F) towards the gap (G); a central strip (3) supported in use on the outer surfaces (21, 22) of the lateral supports (1, 2) and having its own outer surface (32) closing the gap and means (30, 31) for retaining the central strip (3) in its use position.

Description

EXPANSION JOINT

Field of the Invention

The present invention relates to an expansion joint, that is to say a joint allowing expansion at a gap between exposed surfaces of two adjacent parts of a building. Background of the Invention

In buildings of many different sizes and types, various parts of a building may tend to move with respect to other parts, particularly as a result of thermal expansion, but also for other reasons such as differential settlement of the parts of the building. To accommodate this tendency, joint planes can be provided, across which the neighbouring parts of the building are interconnected only loosely if at all. Nevertheless continuity of internal load support structures, floors for instance, is generally required across the joint planes. Expansion joints can provide such continuity.

Most expansion joints have a central, relatively unsupported and thin member, typically of elastomeric material, which accommodates most of the movements been the neighbouring parts of the building. Because of its thinness and lack of support, this member is susceptible of failure. Further the central member can be a dirt trap, where it includes an upwardly open groove. The Invention

The object of the invention is to provide an improved expansion joint.

According to the invention, a joint allowing expansion at a gap between exposed surfaces of two adjacent parts of building comprises: two lateral supports spaced in use at the gap, each lateral support being adapted to be set along an edge of the exposed surface of its part of the building at the gap. each lateral support having an outer surface, which surface - when the lateral support is set in its use position - inclines shallowly inwardly with respect to the exposed surface towards the gap, a central strip supported in use on the outer surfaces of the lateral supports and having its own outer surface closing the gap and means for retaining the central strip in its use position. Preferably the central strip has a generally V-shaped under side, the under side comprising two under surfaces between them defining an included angle complementary to the included angle between the outer surfaces of the lateral supports when set in use. The complementary included angles may be substantially equal. Alternatively, the under surfaces of the central strip may define a shallower V than that of the outer surfaces of the lateral supports to allow the lateral supports to move out of alignment in shear, with lateral edges of the central strip remaining in contact with the outer surfaces of the lateral supports. In another alternative, the under surfaces of the central strip may be relieved inwardly of its lateral edges to allow the lateral supports to move out of alignment.

Preferably, the means for retaining the central strip in its use position includes a central member extending from the central strip and two lateral members extending oppositely from the central member, and the outer surfaces of the lateral supports are provided on flanges, the lateral members engaging behind the flanges for retaining the central strip in its use position. The central member and the two lateral members may comprise a plurality of discrete elements spaced along the length of the central strip. However it is convenient for the central member and the two lateral members to be continuous along the length of the central strip. In the preferred embodiments, the central member comprises a web extending from the centre of the under side of the strip and the lateral members comprise lateral flanges extending from the distal edge of the web. The lateral flanges of the central strip and the flanges of the lateral supports each have complementary formations at their distal edges, which formations captivate edges of the lateral supports' flanges between the central strip and its lateral flanges. The formations on the lateral flanges of the central strip are lips turned towards the central strip as such, and the formations on the flanges of the lateral supports are lips turned away from the outer surfaces thereof. The flanges of the lateral supports have under surfaces substantially parallel to the their upper surfaces. The lateral flanges of the central strip have outwards surfaces facing these under surfaces and similarly parallel therewith in the normal orientation of the central strip The respective lips have faces facing these outwards and under surfaces. The lips are similarly parallel and are of a height transversely of the extent of the flanges for these faces of the lips to abut the surfaces which they face with the under side of the central strip as such supported by the lateral supports. Under surfaces of the flanges of the lateral supports are faced by opposite surfaces which together with the under surfaces define grooves of a width substantially equal to the height of the formations at the distal edges of the lateral flanges of the central strip, these flanges being captivated in the grooves.

It is possible for the lateral supports to comprise basic supports and outer cappings providing the outer surfaces of the supports.

Conveniently, the lateral supports each have a ribbed web and the joint includes two housings, each having a ribbed groove for height adjustable accommodation of the web of a respective one of the lateral supports. The central strip may be of rigid material, such as metal, and rest on the upper surfaces of the lateral supports. Alternatively, the central strip may be of relatively more flexible material, such as hard plastics or elastomeric material, and be urged by its deformation and or deformation of its lower lateral formations into resilient contact with the upper surfaces.

The central strip may be a coextrusion of a resilient wear strip and a harder substrate. The central strip may include an internal, metal, reinforcing strip.

The outer surfaces of the lateral supports may incline at between 25° and 10° with respect to the said exposed surface.

To help understanding of the invention, a specific embodiment and a variant thereof will now be described by way of example and with reference to the accompanying drawings, in which: The Drawings

Figure 1 is a cross-sectional end view of an expansion joint of the invention;

Figure 2 is a similar view of the expansion joint of Figure 1 in a different configuration, showing self-centring of its central strip;

Figure 3 shows in a view similar to Figure 1 a variant of the expansion joint shown in Figure 1;

Figure 4 is a cross-sectional view of an alternative bridge piece for an expansion joint of the invention; and

Figure 5 is a similar view of another alternative bridge piece. The Preferred Embodiment

The expansion joint shown in Figures 1 and 2 has two lateral supports 1,2 of extruded aluminium arranged in use on opposite sides of a building joint plane I, the building having floor sections F, in which the joint is set. A central strip 3 bridges a gap G between the lateral supports 1,2. The lateral supports are themselves supported in housings 4,5. Each of these is comprised of two aluminium extrusions 6,7. The inner extrusion 6 has a base plate 8 overlying a base plate 9 of the other and captive in grooves defined by lips 10. The base plates 8,9 have upstanding flanges 11,12 with ribs 13 arranged on both flanges in vertical registration with each other. The lateral supports have complementary ribs 14 on opposite sides of a depending web 15. The arrangement is such that the lateral supports 1,2 can be set at selected heights with respect to the housings 4,5, as may be seen by comparison of Figures 1 and 2. The lateral supports can be anchored in the housings by means of screws 16, fixed in the flanges 11. The housings themselves can be secured to the floors (before they are made up to the height of the top of the lateral supports 1,2) by means of fixtures - not shown - passed through the base plates 8,9.

The lateral supports 1,2 have inclined upper surfaces 21,22 with horizontal margins 23. The inclined surfaces slope shallowly down at approximately 30° towards the gap G. Beneath the upper surfaces there is a groove 24 in each support, with upper and lower faces 25,26 parallel to the respective upper surfaces 21,22. The grooves are open towards the gap G, with ribs 27 depending at the mouths of the grooves from the flanges 28 defined by the upper surfaces 21,22 and the upper faces 24.

The central strip 3 has a depending central web 30, from the bottom edge of which two flanges 31 extend into the respective grooves 24. With reference to the normal disposition of the central strip with its top surface 32 horizontal, the flanges 31 are parallel to the upper surfaces 21,22. The flanges 31 have upwardly extending ribs 33 at their free edges and are of a thickness to be a sliding fit in the mouths of the grooves 24 at the ribs 27, with the bottom of the flanges just clearing the lower faces 26. Such clearance is necessary to permit the central strip to rotate by a small amount in the event of the lateral supports becoming vertically displaced. Also to facilitate this, the under-surface of the central strip 3 is relieved at 34, whilst being generally parallel to the upper surfaces 21,22.

Should the central strip become displaced from a central position between the lateral supports (with the latter level) as the joint expands, the strip becomes rotated from its normal position as shown in Figure 2. The transverse distance t in the strip between its top edges 35 is greater than the transverse distance w between its ribs 32, with the result that the rib and top edge at the side of the strip 3 remaining closest in to the centre are urged by the geometry of the arrangement into tight engagement with the flange 28. The torque necessary to cause this engagement is caused by reaction between the other, remote top edge 35. Since this top edge is comparatively further from the engaged rib 33 than its top edge, the reactive force at the remote top edge is comparatively less. The result is that the friction at the remote top edge is less. Accordingly, further separation of the joint will result in movement at the remote top edge. Thus the strip is self-centring on expansion of the joint. Forced lateral displacement of the strip with the joint wide open cannot result in the strip becoming disengaged from one side due to engagement of the ribs 27 on the lateral supports with ribs 33 on the strip. Variants The invention is not intended to be restricted to the details of the above described embodiment. Figure 3 shows a variant in which lateral supports 101,102 are supported in housings 104,105, which are each single extrusions as opposed to the dual extrusions 6,7 of the first embodiment. The housings 104,105 each have a single base plate 108 and include a void 140 beneath their ribbed upper groove 141 in which the lateral supports 101,102 are accommodated. The provision of the void adds height to the housings 104,105. The lateral supports 101,102 are provided with cappings 142,143 on which the central strip 103 is supported. This arrangement allows the bridge piece 103 and the cappings 142,143, which are visible in use, to be of comparatively more expensive material than the lateral supports 104,105 and the housings 104,105, which are invisible. The angle of the outer surfaces of the cappings 142,14 is 17°. Other angles have been satisfactorily used, namely 22° and 14°.

Further variants of the bridge piece are shown in Figures 4 and 5. In Figure 4, the bridge piece 203 is a co-extrusion of two plastics materials. An exposed wear surface 2031 is of a relatively more resilient material, whilst a substrate 2032 is of a stronger material. The substrate comprises the majority of the bridge piece, whils the wear surface is a recessed surface strip. The substrat is likely to be so hard as to be easily scratched. However the wear surface deforms to accommodate potentially damagin indentations. Typically the substrate is of rigid PVC material; whilst the wear surface is of flexible PVC material, for instance an elastomeric compound having an "A15" Shore hardness in the region of 60. Such a compound is available from Atochem UK Limited, Stalybridge, Chesire SK15 lPY, England

In Figure 5, the bridge piece 303 is a plastics material extrusion with an internal reinforcement 3033 comprised of a metal strip.

Whilst the above joints have been described in a horizontal orientation for use in floors, they are not restricted in their usefulness to this. They may be used i walls or ceilings as well.

Claims

CLAIMS :

1. A joint allowing expansion at a gap between exposed surfaces of two adjacent parts of a building, the joint comprising: two lateral supports spaced in use at the gap, each lateral support being adapted to be set along an edge of the exposed surface of its part of the building at the gap, each lateral support having an outer surface, which surface - when the lateral support is set in its use position - inclines shallowly inwardly with respect to the exposed surface towards the gap, a central strip supported in use on the outer surfaces of the lateral supports and having its own outer surface closing the gap and means for retaining the central strip in its use position.

2. An expansion joint as claimed in claim 1, wherein the central strip has a generally V-shaped under side, the under side comprising two under surfaces between them defining an included angle complementary to the included angle between the outer surfaces of the lateral supports when set in use.

3. An expansion joint as claimed in claim 2, wherein the complementary included angles are substantially equal.

4. An expansion joint as claimed in claim 2, wherein the under surfaces of the central strip define a shallower V than that of the outer surfaces of the lateral supports to allow the lateral supports to move out of alignment in shear, with lateral edges of the central strip remaining in contact with the outer surfaces of the lateral supports.

5. An expansion joint as claimed in claim 2, wherein the under surfaces of the central strip are relieved inwardly of its lateral edges to allow the lateral supports to move out of alignment in shear, with the lateral edges of the central strip remaining in contact with the outer surfaces of the lateral supports.

6. An expansion joint as claimed in any preceding claim, wherein the means for retaining the central strip in its use position includes a central member extending from the central strip and two lateral members extending oppositely from the central member, and the outer surfaces of the lateral supports are provided on flanges, the lateral members engaging behind the flanges for retaining the central strip in its use position.

7. An expansion joint as claimed in claim 6, wherein the central member and the two lateral members comprise a plurality of discrete elements spaced along the length of the central strip.

8. An expansion joint as claimed in claim 6, wherein the central member and the two lateral members are continuous along the length of the central strip.

9. An expansion joint as claimed in claim 6, claim 7 or claim 8, the central member comprises a web extending from the centre of the under side of the strip and the lateral members comprise lateral flanges extending from the distal edge of the web.

10. An expansion joint as claimed in claim 9, wherein the lateral flanges of the central strip and the flanges of the lateral supports each have complementary formations at their distal edges, which formations captivate edges of the lateral supports' flanges between the central strip and its lateral flanges.

11. An expansion joint as claimed in claim 10, wherein the formations on the lateral flanges of the central strip are lips turned towards the central strip as such, and the formations on the flanges of the lateral supports are lips turned away from the outer surfaces thereof.

12. An expansion joint as claimed in claim 11, wherein the flanges of the lateral supports have under surfaces substantially parallel to the their upper surfaces, the lateral flanges of the central strip have outwards surfaces facing these under surfaces and similarly parallel therewith in the normal orientation of the.central strip, the respective lips have faces facing these outwards and under surfaces which are similarly parallel, and the lips are of a height transversely of the extent of the flanges for these faces of the lips to abut the surfaces which they face with the under side of the central strip as such supported by the lateral supports.

13. An expansion joint as claimed in claim 10, claim 11 or claim 12, wherein under surfaces of the flanges of the lateral supports are faced by opposite surfaces which together with the under surfaces define grooves of a width substantially equal to the height of the formations at the distal edges of the lateral flanges of the central strip, these flanges being captivated in the grooves.

14. An expansion joint as claimed in any preceding claim, wherein the lateral supports comprise basic supports and outer cappings providing the outer surfaces of the supports.

15. An expansion joint as claimed in any preceding claim, wherein the lateral supports each have a ribbed web and the joint includes two housings, each having a ribbed groove for height adjustable accommodation of the web of a respective one of the lateral supports.

16. An expansion joint as claimed in claim 15, wherein the ribbed webs are anchored in the ribbed grooves.

17. An expansion joint as claimed in any preceding claim, wherein the central strip and the lateral supports are of extruded metal.

18. An expansion joint as claimed in any one of claims 1 to 16, wherein the central strip is of extruded synthetic material and the lateral supports are of extruded metal.

19. An expansion joint as claimed in claim 18, wherein the central strip is a coextrusion of a resilient wear strip and a harder substrate.

20. An expansion joint as claimed in claim 18 or claim 19, wherein the central strip includes an internal, metal, reinforcing strip.

21. An expansion joint as claimed in any preceding claim, wherein the lateral supports have non-inclined marginal edges.

22. An expansion joint as claimed in any preceding claim wherein the outer surfaces of the lateral supports incline at between 25° and 10° with respect to the said exposed surface.

23. A joint allowing expansion at a gap between exposed surfaces of two adjacent parts of a building substantially as herein before described in Figures 1 and 2 or Figure 3 of the accompanying drawings.