GB2472432A

GB2472432A - Tensioning device

Info

Publication number: GB2472432A
Application number: GB0913721A
Authority: GB
Inventors: Anthony Nigel Moresby Browne
Original assignee: FAB HOLDINGS Ltd; FABRIC ARCHITECTURE HOLDINGS Ltd
Current assignee: FABRIC ARCHITECTURE HOLDINGS LIMITED
Priority date: 2009-08-06
Filing date: 2009-08-06
Publication date: 2011-02-09
Also published as: GB0913721D0

Abstract

A tensioning device comprises a body10having first and second opposing grooves16,18. The first groove16is of re-entrant form and is adapted to receive an element to be secured, such as a keder or dumbbell connector. The second groove18includes opposing groove faces28, the faces28being ridged with the ridges30of one of the groove faces28being aligned with the recesses32between the ridges30of the other of the groove faces28, so that the ridges and recesses of the groove faces together form a partial screw thread which can receive a threaded bar. Tightening of the threaded bar in the second groove can exert a pull on fabric secured therein via a keder or dumbbell connector.

Description

Tensioning Device This invention relates to a tensioning device for use in securing a fabric material to a support and for achieving a desired degree of tensioning and/or re-tensioning in the fabric.

Tensioned fabric structures are in well known use, for example in forming canopies, covered walkways or the like, or in the formation of internal or external structures, such as suspended ceilings and wall panels.

One way in which fabric material has been secured to a support is by way of a keder located within a fold formed at or secured to an edge of the fabric. A keder (or bolt rope) is a strip of material attached to a fabric membrane and used to securely slide through grooves within an extrusion. The keder and surrounding fabric are fitted into a luff groove of a tensioning member which is bolted to the support. Adjustment of the bolts used to secure the tensioning member to the support adjusts the tension of the fabric.

Although such arrangements function adequately, assembly tends to be very time consuming as openings in the tensioning member and support need to be accurately aligned whilst a bolt or stud is introduced, and fitting of a nut to the bolt under such circumstances is fiddly and often results in the nut becoming dislodged or lost. It is an object of the invention to provide a tensioning device of simple and convenient form and in which at least some of the disadvantages mentioned hereinbef ore are overcome or are of reduced effect.

According to the invention there is provided a tensioning device comprising a body having first and second opposing grooves, wherein the first groove is of re-entrant form and is adapted to receive an element to be secured, and the second groove includes opposing groove faces, the faces being ridged with the ridges of one of the groove faces being aligned with the recesses between the ridges of the other of the groove faces.

In use, the ridges and recesses of the groove faces of the second groove serve as retaining means with which the screw threads of a bolt can engage. It will thus be appreciated that, in use, a bolt or stud passing through an opening provided in a support can be engaged with a corresponding part of the second groove, avoiding the time-consuming and fiddly tasks of aligning openings, and introducing a bolt into engagement with a nut. Assembly can thus be simplified.

The tensioning device of the present invention is preferably of extruded form, such as an aluminium or plastics extrusion, more preferably an aluminium extrusion.

The first groove is conveniently of part cylindrical form and adapted to receive a keder or head of a dumbbell connector. However, this need not always be the case and other arrangements are possible.

The invention further relates to a fabric structure comprising a support to which a tensioning device as defined hereinbef ore is secured.

The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a sectional view of a tensioning device according to one embodiment of the invention in use; Figure 2 is an enlarged view of the tensioning device shown in Figure 1; and Figure 3 illustrates a typical keder arrangement.

Referring firstly to Figure 1 there is illustrated part of a tensioned fabric structure incorporating a tensioning device 10 in accordance with an embodiment of the invention. The illustrated part of the structure comprises an elongate support 1 2 which, in this case, is adapted to be secured to a building but it could equally be arranged to be of free standing or self-supporting form, or may be arranged to be secured to another support device. The support 12 is conveniently of extruded form, for example it may comprise an aluminium extrusion. The support 12 is shaped to define an elongate pocket 14 into which the tensioning device 10 is fitted. The pocket 14 is of oversized depth, compared to the tensioning device 10 so as to permit the tensioning device to be accommodated in a range of positions. Although of oversized depth, the width of the pocket 14 is only very slightly larger than the tensioning device 10 so that little movement of the tensioning device 10 in that direction is permitted.

The support 12 is provided, at spaced intervals along its length, with a series of openings that open into the base of the pocket 14.

It is to be appreciated that the tensioning device need not be housed within a pocket or other enclosure but rather may form a free-standing or floating arrangement.

The tensioning device 10 comprises an elongate body of generally H-shaped cross-section, adjacent pairs of the limbs of which define first and second oppositely directed grooves 16, 18. As shown in Figures 1 and 2, the first groove 16, or luff groove, is of re-entrant form in that a mouth 20 of the first groove 16 is of relatively narrow form, narrower than the diameter of the part-cylindrical remainder of the first groove 16. Although illustrated as being of part-cylindrical form, the first groove 16 need not be of that shape and other arrangements are possible. The object of the groove is to securely hold a fabric edge whilst allowing it to slide along the length of a keder edge.

An element to be secured to the support 12 by the tensioning device 10 is secured to the tensioning device 10 by including a region retained within the first groove 16. In this case the element comprises a fabric sheet 22, an edge part of which is provided with a folded keder tab 24 securing a cylindrical keder element 26 to the fabric sheet 22. The keder element 26 is located within the first groove 16 with the keder tab 24 and fabric 22 extending from the mouth 20. The keder tab 24 may be secured using a range of techniques, for example by heat welding, suitable adhesives, stitching, riveting, etc. Typically, the keder element 26 will be fed into the first groove 16 from an end thereof during assembly.

The second groove 18 is defined by a pair of opposing groove faces 28, each of which is formed with a series of ridges 30 extending in the longitudinal direction of the tensioning device, the ridges 30 being spaced apart from one another by recesses 32.

The ridges 30 and recesses 32 are defined by angled side walls 34 which, in this arrangement, are angled to one another by an angle X of approximately 60°, and the apexes of the ridges 30 are of rounded form. The arrangement is such that each ridge of each groove face 28 is aligned with, and so opposes, a recess 32 of the other groove face 28.

As shown in figure 1, the tensioning device 10 is located within the pocket 14, in use, with the second groove 18 facing towards the base of the pocket 14. Screw threaded bolt shafts 36 are introduced through the openings provided in the support 10 and are screwed into the second groove 18, the ridges 30 and recesses 32 serving, effectively, as a partial screw-thread with which the thread of the shaft 36 can mate.

Once secured to the tensioning device 10 in this manner, a nut 38 can be tightened on the shaft 36 to draw the tensioning device 10 to a desired position in the pocket 14 to achieve a desired level of tensioning in the fabric 22.

As illustrated, a cover plate 40 may be secured to the support 12 to conceal the tensioning device 10 and enhance the appearance of the structure.

It will be appreciated that the use of the invention is advantageous in that the bolt shafts 36 can be secured at any location along the tensioning device 10, so the accurate positioning and alignment of openings, during assembly, is avoided.

Assembly is thus simplified. Further, by avoiding the use of separate nuts associated with the tensioning device which have to be mated with the associated bolts during assembly, the assembly procedure is further simplified, and the loss of component parts during assembly is reduced.

Although described as intended for use in securing fabric to a support, other elements can be secured using the tensioning device. For example, the head of a dumbbell type connector could be secured using the device.

A number of other modifications and alterations may be made to the arrangements described herein without departing from the scope of the invention.

Claims

CLAIMS: 1. A tensioning device comprising a body having first and second opposing grooves, wherein the first groove is of re-entrant form and is adapted to receive an element to be secured, and the second groove includes opposing groove faces, the faces being ridged with the ridges of one of the groove faces being aligned with the recesses between the ridges of the other of the groove faces.
2. A device according to Claim 1, wherein the first groove is of part cylindrical form and is adapted to receive a keder or head of a dumbbell connector or the like.
3. A tensioning device substantially as hereinbefore described with reference to the accompanying drawings.
4. A fabric structure comprising a support to which a tensioning device according to any of the preceding claims is secured.
5. A structure according to Claim 4, wherein the tensioning device is received within a pocket formed in the support.
6. A structure according to Claim 5, wherein the tensioning device is secured to the support by a screw threaded element which is secured to the tensioning device by having the screw thread thereof extending into the second groove, the screw thread engaging with the ridged groove faces of the second groove.
7. A structure according to Claim 6, wherein the screw threaded element extends through an opening provided in the support.
8. A structure according to Claim 7, wherein the opening opens into the base of the pocket.