Technical Field

This invention relates to a collapsible, self-supporting fabric shelter.

Background Art

Collapsible self supporting fabric shelters are reasonably well known and typically comprise a fabric canopy, a collapsible canopy support structure and collapsible legs.

Shelters of this kind find relatively common usage as advertising media, with the fabric of the shelters typically being used as a substrate for the display of advertising or graphics material. A common complaint levelled at these fabric shelters, when used forthis purpose however, is that the structures thereof fail to provide tension support to the canopy fabric sufficient to provide a surface that is acceptably smooth, the inadequate tension of the fabric resulting in folding and creasing of the fabric across its surface, thereby lessening the visibility and impact of the graphics material on the fabric surface. 1 Disclosure of Invention

2 According to the invention a collapsible, self-supporting fabric shelter is provided that is

3 extendible from a first collapsed position to an erected position which provides a canopy

4 held under tension in a domed umbrella form by flexible ribs urged upwardly into a bowed

5 form, and held in position, by a twice braced support.

e Each flexible rib is preferably held in an upwardly bowed form by a support hinged to a

7 slider slidably engaged with the flexible rib, the twice braced support being urged into s position by a first brace extending from a leg of the shelter to the twice braced support and

9 by a second brace forming part of a T-shaped bracing system. The flexible ribs and the

10 sliders are preferably of a cross-sectional shape adapted to minimise twisting of the flexible n ribs about their longitudinal axes.

12 The flexible ribs may conveniently be housed at their outer extremities in pockets located

13 on the fabric of the canopy, at one end of the ribs, towards the tops of the legs of the

14 structure and, at the opposite end of the ribs, in a four way hub at the apex of the canopy.

15 The hub is preferably adapted to accommodate the ends of the flexible ribs against the

16 rotation or twisting about their longitudinal axes.

17 In the preferred form of the invention each leg is provided with an end block and with a leg

18 slider located intermediate the end block and a lower leg slider, the leg sliders being

19 adapted to move from a first position in which the canopy of the shelter is collapsed, in

20 which first position:

21 the leg sliders are located towards the foot of the leg;

22 the legs are retracted; and

23 a brace extending from a leg of the shelter to the twice braced support, a T-shaped

24 brace and scissor-type linkages pivotally coupled to opposite sliders are closed; and

the leg sliders are adapted to move from the first position to a second position in which:

the canopy is extended under tension to a dome shape by the bow of the flexible ribs;

the legs are locked in an extended position;

the leg sliders are locked in an extended position in a direction towards the top of the legs;

the twice braced support bows each corresponding flexible rib in position;

the twice braced support is braced, first by the brace extending from the leg of the structure and, second, by the T-shaped brace; and

the scissor-type linkages are opened and span the opposing legs to form a lattice beam along the lower periphery of the canopy.

In the shelter of the invention, the leg sliders may conveniently be comprised of an outer shell leg section saddled over and held captive on an inner leg section, the gap between the leg sections being sufficient to enable sand and dirt to pass between them without impeding the relative movement of the leg sliders.

The legs are preferably of robust construction and the leg sliders are adapted to be locked in their extended position by cam locking devices.

Brief description of the drawings

The invention will be further described with reference to the accompanying drawings in which: Figure 1 is a perspective view of one embodiment of the shelter according to the invention, in its erected position and with its canopy fabric in place;

Figure 2 is a similar perspective view of the shelter of Figure 1 in which the canopy fabric is shown cut away to reveal the structure of the shelter;

Figure 3 is a similar perspective view of the shelter of Figures 1 and 2 illustrating only the shelter structure;

Figure 4 includes alternative views of one of the supporting legs of the structure, Figure 4a being an exploded isometric view of the components thereof and Figures 4b and 4c being similar isometric views illustrating the operation of the interengaging extruded tubular leg sections of the leg;

Figure 5 includes alternative views of another leg of the shelter structure illustrating the attachment of the superstructure to the leg structure, Figures 5a and 5b being isometric views showing a lower leg extension slider in different positions and Figure 5c being an exploded view of the components thereof;

Figure 6 is an exploded isometric view illustrating the attachment of the superstructure to the leg structure and the bracing forming part of the superstructure of the shelter of the invention;

Figure 7 is an isometric view of the bracing forming part of the superstructure of the shelter of the invention;

Figure 8 consists of alternative views of a four-way apex hub forming part of the canopy support structure of the shelter, Figure 8a being a partial exploded isometric view of the hub; Figure 8b being a partial isometric view of the hub with the ribs attached thereto in a collapsed position; and Figure 8c being a partial isometric view of the hub with the ribs attached thereto in an extended position; 1 Figure 9 consists of alternative views of a hinge coupling for the flexible ribs

2 forming part of the canopy support structure of the shelter, Figure 9a being a partial

3 exploded isometric view of the hinge; Figure 9b being a partial isometric view of the

4 hinge with the ribs attached thereto in a hinged position; and Figure 9c being a

5 partial isometric view of the hinge with the ribs attached thereto in an extended

6 position;

7 Figure 10 consists of alternative views of a flexible rib slider and a slidable support

8 strut forming part of the canopy support structure of the shelter, Figure 10a being a

9 partial exploded isometric view of the rib slider and strut; Figure 10b being a partial

« Wϊ isometric view of the rib slider, strut and flexible rib; and Figure 10c being a partial 11 isometric view of the slider, strut and rib in an extended position; and

12 Figure 1 1 is a perspective view of the framework of the shelter of the invention in its

13 collapsed position.

Best Modes for Carrying Out the Invention

14 In the drawings, Figure 1 provides a general layout view of a collapsible, self-supporting

15 fabric shelter according to one embodiment of the invention. The invention will be W described with reference to this embodiment by way of example.

17 The shelter illustrated in the drawings includes a fabric canopy 20, which is substantially

18 square in plan view, stretched over the frame structure to be described below.

19 The frame structure includes four legs 21 , one at each corner of the canopy 20.

20 At its centre point, the canopy 20 is provided with a vent arrangement constituted by a vent

21 hole (not shown) covered by a fabric flap 22 that is sewn or otherwise attached to the

22 canopy 20 to shield against the ingress of rain.

23 The framework is readily extendible from a collapsed position (which is shown in Figure 11 ) to the extended position shown in Figures 1 , 2 and 3 for example.

Referring to Figures 2, 3 and 7 in particular, the immediate support of the canopy 20 is provided by flexible shafts or spreader ribs 23 that extend from a central apex to the corners of the canopy, each rib 23 being made up of a pair of components or rib sections 23a, 23b hingedly connected to one another by means of a hinge 23c. In the erected condition of the shelter, the ribs 23 are positioned immediately below and bear up against the canopy fabric to support and extend the fabric into a tensioned, domed configuration. Fabric pockets (not shown) are formed are formed on the underside of the canopy adjacent the corners of the canopy 20 to house an end of each spreader rib 23. The ends of the flexible ribs 23 are not attached mechanically to any part of the structure and are essentially free floating above the tops of the legs 21.

At their centres, the spreader ribs 23 are hingedly connected into a centrally positioned four-way apical hub 24.

Each of the flexible ribs 23 is divided into sections 23a and 23b which are coupled together by a hinge 23c which is shown in its fully open position in Figures 2, 3 and 7 and which is designed to hinge only downwardly from the position shown in these drawings.

Each of the flexible rib sections 23a and 23b has an irregularly pentagonal cross-section, with the apex of the pentagon inverted in the structure in use. The base of the pentagon is relatively wide to provide a flat support surface for the fabric of the canopy and the apical sides of the pentagon are longer than the basal sides thereof, to improve flexibility.

As illustrated in Figure 4, each of the four legs 21 consists of a pair of telescopically nested, essentially tubular extruded aluminium leg sections, the extrusion profiles of which are complemental to allow the inner tube (the inner leg section 25 which faces inwardly into the structure in use) to telescope slidably within the outer tube (the outer leg section 26 which faces outwardly in use). The outer tube 26 straddles and covers the inner tube 25 (in the collapsed form of the structure - Figure 1 1 in particular), with the complemental profiles of the tubes 25, 26 holding the inner tube 25 captive on the outer tube 26. The outer leg section 26 is provided with a cap 27 to minimize the ingress of dust and sand into the gaps between the two leg sections 25, 26. The extrusion profiles of the leg sections 25, 26 are designed to provide sufficient space between the slidably interengaged slideways to facilitate automatic gravitational discharge of any sand and grit that might get into the slideways or to permit flushing with water if necessary.

For additional stability, each leg 21 is provided with a foot 28 fitted to the lower end of the outer leg section 26.

The leg sections 25, 26 are provided with a cam-locking device 29 consisting of a handle and a cam wheel 29a which clips firmly and durably into a female component 29b positioned on the inner wall of the outer leg section 26. On the release of the cam-locking device 29, the leg sections 25, 26 are able to telescope by sliding relatively to each other through from the collapsed position of the structure illustrated in Figure 11 to the erected form thereof illustrated in Figures 1 to 3 in particular. A partially extended position of the structure is shown in Figure 5a and a partially collapsed position is shown in Figure 5b. At any position along the travel of the leg sections 25, 26, the sections can be locked to one another in a selected position by the cam-locking device 29. The legs 21 can also be adjusted independently of one another for the easy adjustment of the lengths of the legs 21 to accommodate any terrain on which a user might want to erect the shelter.

The attachment of the superstructure to the legs 21 is illustrated in some detail in Figures 5, 6 and 7.

Figure 5 illustrates the use of sliders 30, 31 of extruded aluminium profiled complementally to the outer cross section of the inner leg section 25. A lower leg slider 30 and an intermediate leg slider 31 are mounted on the inner leg sections 25 of the legs 21. The lower leg slider 30 has a pivotable rib support post 34 hingedly connected thereto. At its opposite end, the rib support post 34 carries a rib slider 35 that is hinged to the post 34, which will be described in more detail with reference to Figure 10.

As illustrated in Figure 5, the lower leg slider 30, and with it the intermediate leg slider 31 , can be locked in its upper extended position by a cam-locking device 36. The cam-locking device 36 comprises a handle and cam wheel pivotably mounted on a stub axles that hook 1 into an axle bracket integrally formed on the lower leg slider 30. Rotation of the cam-

2 locking device 36 in the one direction, by lifting the handle, brings the cam wheel to bear

3 against a locking groove formed within the outer surface of the inner leg section 25 to lock

4 the lower slider 30 in position at that point. The cam-locking device 36 is unlocked by

5 simply depressing the handle again.

6 The rib support post 34 is pivotably mounted in a pivot hole formed in a bracket integral

7 with the intermediate leg slider 31 by means of a pivot stud 38 of plastics material which is

8 press fitted into a stud receiver 39, also of plastics material. The stud receiver 39 is s pressed into the open tubular end of the rib support post 34.

10 Similar pivot studs 38 and stud receivers 39 are used throughout the structure wherever

11 the end of a strut or channel must be pivoted to a bracket. In each case, the stud receiver

12 is externally complemental to the inner cross section of the strut or channel into which it

13 must be pressed.

u The studs 38 and stud receivers 39 enhance the structural integrity of the shelter structure.

15 As can be seen from the drawings and Figures 4 and 5 in particular, the components used

W in the construction of the shelter are of robust design and material as compared to known

17 shelter structures. Unlike prior art structures, which typically have simple square or annular

18 cross-sectional legs and bracing, the profiles of the structural parts of the shelter of the

19 invention are purpose designed to enhance the function each part is to perform An

20 example is the flat inverted pentagonal profile of the ribs 23. Another example is to be

21 found in the arrangement and profiles of the legs 21 , in which the more massive outer leg

22 sections 26 positioned at base level, which is the reverse of the leg arrangements of prior

23 art structures.

24 Another example of the enhanced structural integrity of the shelter structure is to be found

25 in the use of double-ended pivot studs 42 wherever possible. The studs 42 do not extend

26 through only one wall of each of the pivoted parts, typically channels or struts, which

27 means that hole forming is required through only one wall of a given channel or strut, with

28 the result that the strength of the channel or strut is largely preserved. In the prior art, both

29 walls of such channels are drilled through to receive pivot fulcrums which results in the

30 weakening of the channel sections. 1 In addition and where appropriate, the open ends of the channel sections are provided with

2 end caps, such as the stud receivers 39. Another such cap 27 is described above with

3 reference to Figure 4a.

4 The legs 21 are also closed off with end caps 40 (Figure 6), which mount onto end blocks

5 32 constituted by extruded aluminium sections profiled complementally to the outer cross

6 section of the inner leg section 25 and secured to the tops of the leg sections 25 to assist

7 in preventing the sliders 30, 31 from sliding off the end of the leg section 25.

8 The end cap 40 is formed with a hole adapted to receive a ribbed plug 33 which, in use, will

9 be inserted into the hole in the end cap 40 through a grommet (not shown) let into the 0 canopy fabric. The plugs 33 on each of the legs 21 retain the fabric of the canopy 20 on 1 the shelter structure in use. 2 Turning to Figure 6 read with Figures 2, 3 and 7 it can be seen that the four sides of the 3 shelter superstructure, once erected, are constituted by lattice struts 41 pivotably 4 connected to one another to make up lattice webs constituted only by diagonal lacing

15 without the structural sections normally associated with lattice beams or girders. The

16 diagonal lacing struts 41 are pivotably connected to one another, in a scissors linkage, to

17 permit the four lattice webs made up of the struts 41 to extend and retract during erection /8 and collapsing of the shelter respectively.

f 9 Figures 6 and 7 (in particular) illustrate the attachment of the lattice struts 41 to an inner leg 0 section 25 by means of the intermediate leg slider 31 and the end block 32. The

21 intermediate leg slider 31 has two lattice struts 41a, 41b hinged to it on pivot studs 38 and

22 stud receivers 39, both protruding upwardly and away from the leg section 25.

23 The end block 32 also has two lattice struts 41c, 41 d hinged to it on pivot studs 38 and

24 stud receivers 39, both protruding downwardly and away from the leg section 25.

25 The lattice struts 41a, 41b, 41c, 41 d connected to each leg section 25 form the first of a

26 chain of links 41 of a scissors linkage that makes up the lattice web extending about the

27 periphery of the superstructure of the shelter. In the example illustrated, an additional pair of lattice struts 41 is pivotably connected into each side of the shelter, essentially constituting an intermediate link per side. The size of the shelter can be increased, within practical bounds, by increasing the number of intermediate links.

The lattice struts 41 making up the intermediate links are pivotably connected to the lattice ^' struts 41a, 41 b, 41c, 41 d connected to each leg section 25 by means of double-ended pivot studs 42.

As indicated above, the spreader ribs 23 are double-braced. This is achieved by double- bracing the rib support post 34 by means of a first brace element 43 hingedly connected to the end block 32 and a second brace element 46 hingedly connected into a cross-bracing system.

The first brace element 43 is connected between end block 32 and the rib support post 34 by hinge connections at either end. The brace 43 is connected to the end block 32 by means of pivot studs 38 and stud receivers 39 and at its other end, the brace 43 is connected to the rib support 34 by means of a double-ended pivot stud 42.

Referring to Figure 7 in particular, it can be seen that each second brace 46 forms part of a bracing system that is connected to the lattice webs extending about the periphery of the shelter superstructure and that acts diagonally across each corner of the structure (in plan - when erected), but which also provides additional bracing to the ribs 23, thereby acting to stiffen the structure further against moderate to strong winds. The bracing system is essentially in an inverted T- shape when the shelter is erected, the cross member of the T being composed of two struts 44a, 44b that extend diagonally across each corner of the structure, being pivotally connected, at their ends, to the lattice struts 41 a, 41 b extending from the intermediate slider 30 on the leg 25 and to each other at a hinge point 45.

The second brace element is constituted by a brace 46 that is pivotally attached, at one end, to the struts 44a, 44b at their hinge point 45 and, at its opposite end the brace 46 is pivotally attached, at 47, to the rib support post 34. At either end, double-ended pivot studs 42 are used to attach the second brace 46. 1 When the shelter is collapsed, by the user pushing the legs 21 inwardly and towards the

2 centre point of the shelter, the hinge points 45 and 47 are biased downwardly by the inward

3 pressure on the legs 21 with little real effort on the part of the user.

4 The four-way apex hub 24 of the invention is illustrated in greater detail in Figure 8. The

5 hub 24 has four extensions 48 protruding outwardly from the centre point of the body of the 8 hub 24. Each extension 48 has a pair of side walls 49 formed with holes adapted to

7 receive a hinge pin 50.

8 At its free end, each rib section 23a, 23b is fitted with an end piece 51 formed with a cavity

9 that is internally complemental to the profile of the ribs 23 so that the end of each spreader

10 rib 23 can be pressed into the cavity.

11 The hinge pins 50 pass through the side walls 49 and the end pieces 51 secured to the f 2 end of each spreader rib 23a. The body of the hub 24 prevents the end pieces 51 from

13 pivoting upwardly to a position above the horizontal as illustrated in Figure 8c, but there is

14 no impediment to the end pieces 51 pivoting downwardly as shown in Figure 8b. When

15 moving to either such position (or any intermediate position), the end pieces 51 carry both

16 lengths 23a and 23b of the flexible ribs 23 with them.

^7 Figure 9 illustrates the construction of the hinge 23c which couples the flexible rib sections

18 23a and 23b together. When the shelter is in its erected position, the hinge 23c is in its

19 open position as shown more fully in Figure 9c and the flexible ribs 23a, 23b are blocked

20 by the body of the hinge 23c from moving upwardly beyond the horizontal position shown.

21 When the shelter is in its collapsed position, the hinge 23c moves to its closed position as

22 shown in Figure 9b. Each rib section 23a, 23b is terminated in an end piece 50 (such as

23 that illustrated in Figure 8) and the two wings of the hinge 23c consist of a pair of side walls

24 52 through formed with holes adapted to receive an end piece between the side walls 52.

25 Figure 10 illustrates in greater detail how the rib support post 34 is attached to the spreader

26 rib 23b by means of the rib slider 35. The rib slider 35 includes an integral bracket formed

27 with a hole and pivot stud 38 passes through the hole and a corresponding hole formed in 2δ the end of the rib support post 34 where the end of the pin stud 38 is held captive by a stud 1 receiver 39 pressed into the end of the rib support post 34.

2 The body of the rib slider 35 is in the form of a slideway sleeve that is shaped

3 complementaily to the profile of the rib 23.

4 In use, the shelter of the invention is kept in a bag in the collapsed form illustrated in Figure

5 11. At a site selected for erection, the shelter is removed from the bag and the legs 21 are

6 pulled apart to extend the scissor-type lattice webs 41 to a limited degree. The cam-

7 locking devices 29 on the legs are then released to permit the inner leg sections 25 to be

8 raised upwardly and relocked in appropriate positions.

θ The next step would be to release the cam-locking devices 36 on the lower leg sliders 30.

10 With the cam-locking devices 36 so released, the lower leg slider 30 can be pushed

11 upwardly.

12 Upward movement of lower leg slider 30 has a number of consequences:

13 the lattice webs 41 are extended sideways (to the extent permitted by the fabric of

14 the canopy 20);

f 5 the rib support posts 34 are pushed upwardly to exert an upward force on the

16 flexible ribs 23, the rib support posts 34 sliding along the ribs 23 by means of the rib

17 sliders 35 to the point that the rib support posts 34 are locked in position by the

18 braces , 46;

19 the outer extremities of the ribs 23 are pushed into the pockets in the comers of the

20 canopy fabric 20; and

21 the inner extremities of the ribs 23 are pushed up against the four way apex hub

22 24, thereby bowing the ribs upwardly, the bowing being assisted by the upward

23 force exerted by the rib support posts 34, thereby extending the canopy 20 under

24 tension into a taut, properly tensioned dome shape. Having achieved the set-up of the shelter as outlined above, the cam-locking devices 36 can then be locked in position. Both sets of cam-locking devices 29 and 36 permit for easy adjustment and realignment of the shelter to suit almost any site requirements.

The resultant collapsible shelter provides a spacious, unencumbered interior of relatively lightweight and novel robust and wind resistant construction when compared to the relatively flimsy shelters of the prior art.

Although the invention has been described above by way of one embodiment, numerous modifications and additions would be apparent to a person skilled in the art.

For example, whilst the cross sectional profile of the flexible ribs 23 and their associated parts have been described as being pentagonal, the cross sectional formation could take any suitable form which would prevent the flexible ribs from rotating or twisting about their own longitudinal axes and, preferably, also minimising any confusion by the user when fitting together or replacing the relevant components.

It is thus intended that the scope of the present specification should be understood as extending to all such modifications and/or additions and that the scope of the invention should not be read as being limited to the particular embodiment described.