This invention relates to a portable structure. In particular, the portable structure is configurable between stored and erected conditions. Further, the invention relates to a method of storing and a method of erecting a portable structure of the present invention.

Portable structures, for example tents, are well known in the art. As tents have evolved, there has been a move towards tents which require less connection or assembling of components and, therefore, a more easily and quickly erected portable structure. The flexible frame and tent disclosed in US Patent No. 4,569,362 is just one example of prior art which disclose tent arrangements. In particular, US

4,569,362 discloses a frame including a flexible resilient base ring and a flexible resilient top ring having a top covering removably attached. The top ring contains a pair of diametrically opposing ferrule connectors for attaching the top ring around the outside of a flexible resilient arched member. The top ring is spaced from the base ring by two tubular sleeve members which are fastened at respective ends to the base ring and top ring. It will therefore be seen from this particular disclosure, in particular, that the base ring and the top ring must be put together prior to attaching those rings to the respective parts of the tent.

Further, two tubular sleeve members must then be attached to the two rings to provide them in a spaced relationship.

Finally, an arched member must also be added to the top ring to provide the tent in the erected condition.

Accordingly, in order to speed up erection of portable structures, and simplify the erection thereof, there is a need for an improved portable structure which provides for a more time efficient and simplified erection of the portable structure .

The present invention is aimed at providing portable structures without the disadvantages associated with the prior art mentioned above and the present invention provides for easy and speedy erection of a portable structure.

Accordingly, the present invention provides a portable tunnel structure, configurable between a stored and an erected condition, wherein in the erected condition the portable tunnel structure has an elongate form with a first end longitudinally spaced from a second end;

the portable tunnel structure comprising:

a) a flexible material covering defining a tunnel passageway;

b) a plurality of first resilient members each connected to the flexible material to extend at least partially around a circumference of the tunnel passageway; c) a plurality of second resilient members each connected to the flexible material to extend longitudinally along the tunnel passageway;

wherein in the erected condition the first resilient members circumferentxally support the flexible material covering and the second resilient members hold adjacent first resilient members longitudinally apart from one another;

wherein adjacent first resilient members are

circumferentxally rotatable relative to one another so as to bring said adjacent first resilient members longitudinally towards one another in order to collapse the portable tunnel structure into the stored condition; said circumferential rotation of adjacent first resilient members being

accommodated by resilient deformation of the second resilient members and twisting of the flexible material covering.

Preferably the portable tunnel structure comprises a plurality of longitudinally arranged sections, each section bounded at each end by a first resilient member.

Preferably each section is collapsible independently of ad acent sections.

Preferably each section comprises two or more second resilient members.

In, one embodiment the first resilient members are elongate with a first end and a second end and adopt an arched shape when the. portable tunnel structure is in the erected condition.

The tunnel passageway in the erected condition may have a substantially U, square, triangular or trapezoidal cross- sectional shape.

The flexible material covering may comprise a wall part to which the first resilient members are connected and a floor part which is free of first resilient members.

Alternatively, the flexible material covering may comprise a wall part to which the first resilient members are connected, but no floor part.

In another alternative, the flexible material covering may comprise a wall part to which the first resilient members are connected, and a plurality of flexible members, such as straps, which under tension serve to support the cross-sectional shape of the tunnel structure in the erected condition.

In another embodiment the first resilient members are closed loops and adopt a substantially round shape when the portable tunnel structure is in the erected condition. The tunnel passageway in the erected condition may have a substantially round cross-sectional shape.

The flexible material covering may comprise a plurality of panels.

The first and/or second resilient members may be made from any one or more of spring steel, coiled spring steel, spirally-wound spring steel, fibreglass, flexible plastics material, pre-stressed material, or any other material which when bent, naturally wishes to return to an unbent or straight shape.

The first and second ends may be open. Alternatively, one or both of the first and second ends may comprise a flexible door.

The portable tunnel structure in the erected condition may be straight, curved or comprises one or more bends.

Preferably the portable tunnel structure further comprises pockets in the flexible material for receiving the first and second resilient members.

Preferably the pockets envelop the first and second resilient members.

The flexible material covering may be one or more of fabric, plastics material, polyvinyl chloride (FVCJ , and/or polyethylene (PE) , or other suitable material. The

material, while flexible, is preferably not stretchable.

Although, stretchable, flexible materials may also be used if desired.

Preferably the portable tunnel is arranged such that all components of the portable tunnel structure are provided in both the erected and stored conditions.

Advantageously, the portable structure is arranged such that all components of the portable structure are provided in both erected and stored conditions. Further, the portable structure is arranged such that it provides a unitary portable structure which is capable of being erected and stored without addition or removal of components, or inflation.

The present invention also provides a method of collapsing and erecting a portable tunnel structure of the type comprising:

a) a flexible material covering defining a tunnel passageway;

b) a plurality of first resilient members each connected to the flexible material to extend at least partially around a circumference of the tunnel passageway; c) a plurality of second resilient members each connected to the flexible material to extend longitudinally along the tunnel passageway;

comprising the steps of circumferentially rotating adjacent first resilient members relative to one another so as to bring said adjacent first resilient members

longitudinally towards one another in order to collapse the portable tunnel structure into a stored condition; said circumferential rotation of adjacent first resilient members being accommodated by resilient deformation of the second resilient members and twisting of the flexible material covering.

Preferably the method comprises sequentially

circumferentially rotating pairs of first resilient members relative to one another so as to bring said pairs of

adjacent first resilient members longitudinally towards one another in order to collapse to portable tunnel structure sequentially one section at a time. Preferably once collapsed in the stored condition, the plurality of first resilient members are piled one on top of another.

Preferably erecting the portable tunnel structure comprises releasing the first resilient members from their stored condition and allowing the first and second resilient members to elastically recover so as to move the flexible material covering into the erected condition.

In order that the invention may be fully disclosed, embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is perspective view of a part of a first embodiment of portable tunnel structure according to the present invention;

Figure 2 is a perspective view of the first embodiment Of portable tunnel structure according to the present invention;

Figures 3a to 3e are line drawings illustrating

collapsing of the portable tunnel structure of Figure 2 into a stored condition;

Figures 4a to e are photographs equivalent to the views of Figures 3a to 3e illustrating collapsing of the portable tunnel structure of Figure 2 into a stored

condition;

Figure 5 is a perspective view of a second embodiment of portable tunnel structure according to the present invention;

Figure 6 is a perspective view of a third embodiment of portable tunnel structure according to the present

invention; Figure 7 is a perspective view of a fourth embodiment of portable tunnel structure according to the present invention;

Figure 8 is a perspective view of a fifth embodiment of portable tunnel structure according to the present

invention;

Figure 9 is a perspective view of a sixth embodiment of portable tunnel structure according to the present

invention;

Figure 10 is a perspective view of a seventh embodiment of portable tunnel structure according to the present invention; and

Figure 11 is a perspective view of a eighth embodiment of portable tunnel structure according to the present invention.

Figure 1 shows a section of a portable tunnel structure in an erected condition, indicated generally by reference 1, according to the present invention. The portable tunnel structure 1 has a roughly square cross-section at right angles to a longitudinal axis of the section, the axis being shown by reference A.

The section of the structure 1 is formed from a

covering of flexible material 5 that is annular in shape to define a tunnel passageway 3 through the centre along axis A. The flexible material may be formed from a plurality of separate panels that are connected together, for example, by stitching. The tunnel passageway 3 comprises a floor part 8, intended during use to be lowermost, and an arched part 9, that extends up and over to join to both lateral sides of the floor part 8 to form effective sides and roof of the tunnel passageway 3 , The flexible material 5 may be, for example, polyvinyl chloride (PVC) or polyethylene (PE) .

The flexible material 5 is held in shape in the erected condition as shown by a plurality of resilient members 2, 6. Two first resilient members 2 are provided at either end of the section.

The first resilient members 2 are in the form of flexible sprung rods 2 that are received in pockets 4 formed in the flexible material 5. The sprung rods may be coiled spring steel. The pockets 4 may be formed by turning over and sewing the edges of flexible material 5 or may be formed by attaching a separate piece of material. The first

resilient members 2 extend along the edge of the arched part 9 but not along the floor part 8. As such, in the erected condition the first resilient members 2 are substantially U- shaped and act to bias the flexible material outwardly to maintain the tunnel passageway 3 open.

Two second resilient members 6 are provided, one on each side of the section, extending between the two first resilient members 2. The second resilient members 6 are received in pockets 7 formed in the flexible material 5. The second resilient members 6 are in the form of flexible sprung rods. The sprung rods may be coiled spring steel. The pockets 7 may be formed by turning over and sewing the edges of panels of the flexible material 5 or may be formed by attaching a separate piece of material. In the erected condition the second resilient members 6 act to hold the first resilient members 2 apart in the longitudinal

direction.

Loop fastenings may be used instead of pockets to hold the resilient members 2, 6 connected to the flexible

material 5. Preferably, the portable tunnel structure comprises a plurality of sections 1 arranged longitudinally as shown in Figure 2. As illustrated, the tunnel comprises three sections 1. However, any required number of sections 1 can be used to obtain a tunnel of the desired length. The tunnel structure has a first open end 10 and a second open end 11 at opposed ends. As shown the tunnel structure is straight and extends along longitudinal axis A. However, by suitable shaping of the flexible material 5 and the second resilient members 6, the tunnel structure can be curved or bent in shape .

The first resilient members 2 define the boundary between sections 1. A Single first resilient member 2 is provided at the interface between each section 1 and first resilient members 2 are provided at each end of the tunnel.

The second resilient members 6 may be separate for each section 1. Alternatively, each second resilient member 6 may extend across more than one section 1.

Figures 3a to 3e show illustrative views of a method of collapsing and storing the portable tunnel structure.

Figures 4a to 4e show equivalent photographic views of the method for ease of reference. However, in the following description the illustrative views of Figures 3a to 3e will only be referred to.

Figure 3a shows the portable tunnel structure in an erected condition. Figure 3e shows the portable tunnel structure in a stored condition. Various states of

operation during the storing/erecting procedure are shown in Figures 3b through to 3d.

Starting from the erected condition shown in Figure 3a, the first section 1' is collapsed by circumferentially rotating the terminal first resilient member 2 ¹ relative to its adjacent first resilient member 2' ' generally about the axis A as shown in Figure 3b. This twisting action causes the second resilient members 6' to deform and bend allowing the first resilient member 2' to come into close proximity with the first resilient member 2' ' where the two members 2' and 2' ' can be grasped in one hand.

Next, as shown in Figure 3c, the second section 1' ' is collapsed by circumferentially rotating the first resilient members 2 ' and 2 ' ' together relative to the first resilient member 2' ' ' . Similar to before, this twisting action causes the second resilient members 6' ' to deform and bend allowing the first resilient members 2' and 2 · · to come into close proximity with the first resilient member 2' ' ' where the three members 2 ' , 2' ' and 2' ' ' can be grasped in one hand.

As shown in Figure 3d this procedure is repeated for the third section 1' ' ' until all four first resilient members 2' to 2' ' ' ' are piled on top of one another in a relatively flat state that can be stored - preferably in a container such as a bag.

The deformation of the second resilient members 6' to

6' ' ' (together with some deformation of the first resilient members 2' to 2' ' ' ') leads to the portable tunnel structure in the stored condition possessing stored elastic energy that can be used to self-erect the structure.

Starting in the stored condition shown in Figure 3e, the tunnel structure can be erected by beginning to

circumferentially rotate the first resilient members 2' to 2' ' ' ' in the opposite sense compared to when the portable structure was collapsed. The stored elastic energy and the biasing effect of the second resilient members 6' to 6' ' ' and first resilient members 2' to 2' ' ' ' results in the structure 'popping' into the erected condition largely without further manual intervention.

The cross-sectional shape of the tunnel structure may be other than square, and may vary along the longitudinal length of the tunnel structure. Figure 5 illustrates a second embodiment in which the cross-section is

substantially triangular. Figure 6 illustrates a third embodiment in which the cross-section is substantially trapezoidal- Figures 7 and 8 illustrate fourth and fifth embodiments in which the cross-section is substantially U- shaped. Figure 9 illustrates a sixth embodiment in Which the cross-section is substantially circular. The third, fourth and fifth embodiments also illustrate the point that the tunnel structures of any of the embodiments discussed herein may comprise only a single second resilient member 6 in each section 1 - here the single second resilient member 6 is provided at the top (roof) of the tunnel passageway in

Figures 6 and 7. Alternatively, the tunnel structures may comprise two or more second resilient members 6 in each section 1 as shown in Figures 8 and 9. he sixth embodiment of Figure 9 also illustrates the point that the tunnel structures of any of the embodiments discussed herein may comprise first resilient member 2 that extend fully around the annulus of the tunnel passageway 3. The first resilient members 2 may be formed as closed loops or may be in the form of elongate rods that are received in circular pockets 7.

Figure 10 illustrates a seventh embodiment which illustrates the point that either or both of the first open end 10 and second open end 11 of the tunnel structures of any of the embodiments described herein may be provided with one or more pieces of flexible material to act as a door for the tunnel structure. As illustrated, the door material comprises two pieces 15 which may be separately gathered up and tied at point 16 to open the entrance. The pieces 15 may have securing means such as poppers or hook and loop fastening to attach the pieces 15 together when in the closed configuration. Preferably, the pieces 15 are formed from the same material as the flexible material 5 of the arched part 9.

Figures 11 and 12 illustrate eighth and ninth

embodiments which illustrate the point that the tunnel structures of any of the embodiments described herein may be modified to remove the floor part 8 of the flexible

material. For example, as illustrated in Figure 10 there may be no floor to the tunnel structure, in this arrangement the first resilient members 2 are configured to adopt a U-shape when in the erected configuration by suitable pre-stressing or shaping. In the embodiment of Figure 12 flexible straps 18 are provided in place of the floor part 8. The flexible straps 18 span between the bases of the tunnel side walls and are tensioned in the erected condition so as to support the tunnel shape. The straps 18 may be of the same material as the flexible material 5 or may be woven nylon or

polyester webbing.

It will be understood by those skilled in the art that various materials may be used to provide material for the flexible material 5 of the portable structure. The material should also be durable and strong, to prevent inadvertent tearing during normal use. It will be understood that various materials may be chosen which provide the required strength and durability beyond those that are provided above as examples. In all embodiments of the invention, the operating procedure to go between stored and erected conditions is simple and quick, and preferably does not require connection or otherwise of external features.