The present invention relates to a tent frame comprising a hub from which extend a plurality of limbs, respective ends of some of which are secured to the hub by way of respective pivots, constituting a first set of pivots, having respective pivot axes which are generally parallel to one another.

One such previously proposed tent frame is described and illustrated in WO 2009/071026 A1. In that construction, the hub is provided with respective sockets for the limbs, which sockets have baffles limiting the downward rotation of the limbs relative to the hub. When the tent is erected, the baffles locate every limb.

Another such previously proposed tent frame is described and illustrated in AU 523506 B2. In that construction, a number of vertex hi nges are spaced apart around a central axis of the tent frame, and each vertex hi nge may be consi dered to consti tute such a hub.

Another such previ ousl y proposed tent frame is described and illustrated in EP 0417919 A1. In that construction, a tent is disclosed having movable tent poles for supporting a flexible tent body. An apex junction member is provided for pivotally supporting one of the ends of each of the tent pol es, the opposite ends of which are held in a fixed position. A tensioning member is provided movable between a normal position in which the tent is collapsed with the tent poles parallel and adjacent to each other, and a tensioned position for tensioning the tent poles in a splayed apart configuration for placing the tent body in an erect position. A latch member is provided for releasably latching the tensioning member in its tensioned position and the tent in its erect position.

Another such previously proposed tent frame is described and illustrated in EP 1445400 A1. In the construction of tent frame described therein, the sai d first set of pivots are located on a first part of the hub, and a plurality of limbs extend from a second part of the hub and are secured to that part of the hub by way of respective pivots, constituting a second set of pivots, having respective pivot axes which are also generally parallel to one another. The first and second parts of the hub are pivoted relative to one another, and sheet material is attached to the limbs of the tent frame so that when the two parts of the hub are pivoted to bring the axes of the sai d second set of pi vots parallel to those of the said first set, the sheet material is opened out to form a canopy supported by the limbs of the frame, and the pivot axes of the first set of pivots are substantially parallel to those of the second.

A disadvantage of this construction is the strength required to pivot the two parts of the hub relative to one another in this fashion to erect the tent. For this purpose respective recesses are formed in the two parts of the hub, into which recesses are inserted the ends of respective levers to enable considerable force to be exerted on the two parts of the hub to bring them together in the foregoing fashion. A latch pivoted to a formation on one of the hub parts is then swung round to latch onto a corresponding formation on the other part of the hub to secure the hub parts together in such an erect condition of the frame, where upon the levers are removed. Such a construction is therefore relatively expensive and complex, and requires a relatively awkward assembly procedure.

The present invention seeks to provide a remedy.

Accordingly, the present invention is directed to a tent frame having the construction set out in the opening paragraph of the present specification, in which respective ends of at least two of the said plurality of limbs are secured to the hub by way of respective pivots, constituting a second set of pivots, enabling the sai d at least two of the said plurality of limbs to be pivoted about respective axes which are transverse, or have a component which is transverse, of the pivot axes of the said first set of pivots whilst the frame is unfolded into an erect condition and whilst it is folded for stowage, the pivots of the first and second set of pivots being fixed in position relative to one another even when the limbs are pivoted about their respective pivots, characterized in that the hub is provided with respective guide cams for at least two limbs attached to the hub by way of ball and socket joints constituting or being included in the said second set of pivots.

This enables a relatively simple and inexpensive construction of tent frame to be made, in such a fashion that its erection is relatively simple.

The said first set of pivots may be spaced apart around the hub.

This provides an even distribution of the support for sheet material when such material is attached to the tent frame.

The said second set of pivots may be located together on one side of the hub.

This again facilitates a relatively easy erection of the tent frame.

The pivots of the said first set of pivots may comprise respective pins extending through respective inner ends of the associated limbs.

This provides a relatively inexpensive way of manufacturing those pivots.

The cams may be such as to generate a movement of the said at least two limbs when the frame is unfolded, which movement is such that the limbs splay away from one another as the latter are rotated about their respective pivots through a first part of such movement at a greater rate than in a second part of that movement.

This increases the extent to which the taughtness of sheet material is spread evenly across the dome it is beginning to form when attached to the frame.

The tent frame may comprise a further limb arranged centrally in relation to the other limbs of the tent frame, which further limb is fixed relative to the hub.

Such a fixed central limb may be in the same position relative to the hub for both the erect condition of the tent frame and the collapsed condition of the tent frame.

The said second set of pivots may be arranged between two pivots of the said first set of pivots.

Such a construction lends itself more readily to erection of the tent frame.

Wth such a construction, the other pivots of the said second set of pivots, viewed in a direction perpendicular to an imaginary line joining the midpoints of the said two pivots of the said first set of pivots, are within those midpoints.

This again affords an even distribution of support for sheet material when it is attached to the tent frame.

The said at least two limbs may be retained in their splayed condition by one or more braces, for example by a rod or bar which may be removeably attached between and to each of those limbs.

At least one of the limbs may be retained in its extended position by means of interengaging parts respectively mounted on the hub and the hub end of the sai d at least one of the limbs, at least one of those interengaging parts being slidable between a first position, in which it accommodates movement of the other of those parts whilst the said at least one of the limbs is brought into its extended position, and a second position in which it engages the said other of those parts to retain the said at least one of the limbs in its ext ended position.

Such a construction enables the speedy erection and collapse of the tent frame.

The sai d at least one of the interengaging parts may be spring-loaded towards the said second position, so that upon movement of the sai d at least one of the limbs towards its extended position, the said one of those interengaging parts is slid by the said other of those i nterengagi ng parts to its sai d first posi ti on, and so that upon the said at least one of the limbs reaching its extended position, the said one of those interengaging parts snaps back to its second position so that those two parts can engage one another in such a manner as to retain the limb in its extended position.

This further facilitates speedy erection and collapse of the tent frame.

At least one of the limbs may be provided with a slider coupled to the said at least one of the limbs in such a manner as to be slidable there along away from and towards the hub, there being two cross-members pivotally connected to the slider and extending therefrom to respective pivots on respective ones of the limbs which are on opposite respective sides of the said at least one of the limbs, whereby when the limbs are moved to their extended positions, the slider can slide along the limb on which it is provided away from the hub so that the cross-members retain the said respective ones of the limbs at a splay angle relative to the said at least one of the limbs.

Such a construction ensures a desired splay angle between the said at least one of the limb and those two limb on opposite sides thereof, and as a result ensures a desi red degree of tensi oni ng of any tent fabric supported by the frame.

The slider may be retained in the position it adopts when the limbs are in their extended positions by means of a clip, pin, latch or over-centre mechanism

The present invention extends to a tent comprising a tent frame made in accordance with the present invention together with sheet material supported by the frame.

The construction of the tent frame is such that such sheet material can remain on the frame duri ng stowage, during its use as a tent, and whilst the tent is being erected and whilst the tent is being collapsed. Thus the sheet material never has to be removed from the frame. The unfolding of the frame results in the sheet material being spread out into a canopy supported by the frame during use, and folding up of the frame results in the sheet material also being folded up for stowage. This therefore provides for efficient and speedy changeover from the folded condition of the tent to the unfolded condition, and vice versa.

Examples of tent frames made in accordance with the present invention will now be described in greater detail with reference to the accompanying drawings, in which:

Figure 1 shows a perspective view of the underside of a hub and limb portions of a tent frame embodying the present invention;

Figure 2 shows a perspective vi ew from above of the tent frame shown in Figure 1, together with part of sheet material supported by the frame;

Figures 3a to 3e show respectively an underneath view, a perspective vi ew f rom above and to one side, a top view, an end view and a side view of the tent frame shown in Figures 1 and 2 in a condition just after unf ol di ng of the frame has commenced;

Figures 4a to 4e, 5a to 5e, 6a to 6e and 7a to 7e show views corresponding to Figures 3a to 3e for successive conditions of the frame as it is unfolded;

Figure 8 is a diagram illustrating the movement of limbs of the frame shown in Figures 1 to 7e between a folded condition of the frame and an unfolded condition of the frame;

Figures 9 to 15 show views which correspond to those of Figures 1 to 7, of a second embodiment of the present invention; and

Figures 16 to 19 show respective perspective views of successive stages in the collapsing of the tent frame shown in Figures 9 to 15.

The tent frame 10 shown in Figures 1 and 2 comprises a hub 12 from which extend a plurality of limbs 14 and 15. Only portions of each limb 14,15 which are cl oser to the hub 12 are shown in Fi gures 1 and 2. A first set of these limbs 14 are connected to the hub 12 by way of respective pivots 16. Each pivot 16 comprises a pin 18 which has its opposite ends fixed to respective flanges 20 and 22 of the hub 12 so that each pi n extends from one flange 20 to the other flange 22. The flanges 20 and 22 are reduced at portions of the hub 12 between the pivots 16. An inner end of the associated limb 14 is provided with the through- hole (not shown) which extends through it and through which extends the associated pin 18. This enables the limb 14 to swing about its associated pivot 16. Furthermore, from this described construction it will be appreciated that the pivots 16 constitute a first set of pivots of the frame 10 the pivot axes of which are parallel to one another.

Viewing the hub 12 along a median bisector thereof, the set of pivots 16 corrprises two outer most pivots of the set, the other two pivots of which appear to be within t hose out er pivots when viewed in that direction.

A fifth limb 14a is rigidly fixed to the hub 12, and extends al ong a median bisector of the hub 12.

A second set of limbs of the frame 10 constituted by the limbs 15 are attached to the hub 12 by way of respective pivots 24 constituting a second set of pivots located between the outer most pivots of the set of pivots s 16.

The pivot 24 of a central one of the limbs 15 comprises a bar (not shown) of the hub 12 which is of ci rcul ar cross-secti on and which extends between two portions of the hub 12 in a direction which is orthogonal to the pins 18. A connector 26 of that pivot 24 comprises a tubular ar portion 28 which receives one end of its associated limb 15 in such a fashion as to be fixed relative thereto.The connector 26 further comprises a ri ng porti on 32 which surrounds its associated bar of the hub 12 so as to be rotatable thereabout.

As shown in Figures 1 and 2, this particular illustrated frame 10 has three limbs 15 with three respective pivots 24. The bar of the central one of these pivots 24 is generally parallel to an imaginary line connecting the outer most pivots 16 of the first set of pivots. The two outer pivots of the set of pivots 24 are constituted by ball and socket joints, or universal joints, to give the associated limb a greater degree of freedom in its ability to be pivoted about the pi vot 24. Fi gure 2 also shows a portion of sheet material 34 which is attached to the limbs 14 and 15.

Figures 3 to 7 show the frame 10 i n successive stages of bei ng unf ol ded from a stowage condition shown in Figure 3 to an unfolded condition shown in Figure 7 in which the combination of the frame 10 and the sheet material 34 constitute a tent, with the limbs 14 and 15 curving i n a manner not shown so that they extend outwardly from the hub 12 and then downwardly towards the ground with the sheet material 34 adopting the shape of a dome to constitute a cover of the tent.

Thus it will be seen that as the frame 10 is unfolded, each limb 14 and 15 swings about its respective pivot relative to the hub 12. As the limbs 14 are fanned out from a position in which they are generally parallel to one another in the folded stowaway condition to a position in which they are spread outwardly from the hub 12 in a star formation, the limbs 15 rotate about their respective pivots 26 between a position in which they are generally parallel to the limbs 14, about pivot axes which are at right angles to those of the set of limbs 14, to a position in which those port i ons of all the limbs 14 and 15 which are close to the hub 12 are in the same general imaginary plane as one another. Furthermore, all the limbs fan out from the hub 12 and from one another, the spacing between the limbs 15 which are now splayed relative to one being slightly less than the spacing between the limbs 14. These limbs 15 support an entrance (not shown) to the tent.

As the limbs 14 and 15 of the frame 10 are unfolded, so the sheet material 34 which is attached to these limbs is also spread out into a dome formation. It therefore remains attached to the limbs 14 and 15 throughout the unf ol di ng procedure.

After use, the tent may be folded up i n st ages also illustrated in Figures 3 to 7, but in reverse order, with the sheet material 34 being folded up as a result of the limbs 14 and 15 being folded together, so that the sheet material remains attached to the limbs 14 and 15 in the folded up stowaway position ready for the next unfolding of the tent when it is next erected.

It will be appreciated that when the tent is in its unfolded, erected condition, what is now the upper side 36 of the hub 12 now has sheet material 34 (not shown in Figure 1) taught just below it and against it with the ends 30 of the limbs 15 remaining recessed in the hub 12.

The limbs 15 may be retained in their splayed condition by means of one or more braces, comprising one or more cross-bars or rods (not shown) extending between and attached to one or more of the limbs 15.

Portions 60 of the hub 12 define respective guide cams for the outer pivots 24 such that the movement of points of the set of limbs 15 which are located outwardly of the hub 12 follow the paths represented diagrammatically in Figure 8. It will be seen from this Figure that the limbs 15 are splayed apart more rapidly during the first portion of the paths 38 near to the ends 40 thereof than they are during the remainder of those paths 38. This reduces the rate of splaying as the limbs 15 are swung outwardly once the tent is in a relatively unfolded condition to increase the extent to which the taughtness of the sheet material 34 is spread evenly across the dome it is beginning to form

The embodiment of the present invention shown in Figures 9 to 15 is substantially the same as the embodiment shown in Figures 1 to 7, except in the following respects.

Firstly, the hub end of the centre of the three legs or limbs 15 is reinforced by a connector 50 which has a tubular portion 52 which receives a hub end of the centre leg 15, and trunnions 54 through which a cylindrical bar (not visible in the Figures) extends from one support block portion 56 of the hub 12 on one side of the connector 52 to another support block portion 56 of the hub 12 on the other side of the connector 52. This construction provides a pivot between the cent re leg or limb 15 and the hub 12. A centre support 58 of the hub 12 through which the bar passes is also provided to add strength to the pivot construction.

On the upper si de of the connector 50 there is provided a hollow arched portion 60 which is open in the direction of the hub 12 and which can be seen more clearly in Figures 10 and 19. This portion 60 has transverse serrations or teeth (not shown) on the interior of its upper arcuate wall. It forms the first part of a snap- action locking device.

The second part of the snap-action locking device is provided by a slidable block 62 secured slidably on the hub 12. The block 62 is formed with an arcuate recess 64 which accommodates a part of the arched portion 60, and a forwardly protruding tongue portion 66 which is visible in Figures 17, 18 and 19. The tongue portion 66 has an upper curved surface 68 as viewed in cross-section, and this upper curved surface 68 has transverse serrations or teeth and has the same radius of curvature as that of the interior of the arched portion 60. The slidable block 62 is slidable towards and away from the front edge of the block 12 and is urged by a spring (not shown) into a forward position further from the rear leg or limb 14a.

Further transverse serrations or teeth (not shown) are also provided on the underside of the tongue portion 66 to engage with transverse serrations or teeth (not shown) on the block 12 when the tent frame is in use.

When the centre leg or limb 15 is pivoted relative to the hub into its extended position, the arcuate portion 60 of the connector 50 engages the slidable block 62 of the hub 12 and urges it rearwardly. When the centre leg 15 is in its fully extended position, the arcuate portion 60 of the connector 50 clears the upper forward edge of the tongue 66 so that the slidable block 62 snaps forward into a position in which the tongue 66 ext ends within the hollow arcuate portion 60 of the connector 50. Only a very slight downward movement of the cent re leg or limb 15 will now be all owed before the teeth of the tongue 66 and the teeth of the arcuate portion 60 of the connector 50 interengage to prevent further such downward movement.

To collapse the tent from the erect condition of the tent frame as shown in Figure 16, the centre leg or limb 15 is urged upwardly to disengage the serrated teeth of the arcuate portion 60 of the connector 50 from those of the tongue 66 so that the slidable block 62 can be slid rearwardly as shown in Fi gure 17. The centre leg or limb 15 is now free to be lowered to the collapsed or stow position as shown in Figures 18 and 19.

Secondly, the centre leg or limb 15 is provided with a flat 70 running along its length. A slider 72 shown for example in Figure 13a surrounds the centre leg 15 and is provided with a corresponding flat (not shown) which engages the flat 70 to prevent rotation of the slider 72 around the centre leg 15. However, the slider 72 is free to slide along the centre leg 15 towards and away from the hub as shown for example in Figures 13a, 14a and 15a. Respective cross-members 74 and 76 are pivotally attached at respective ends thereof to the slider 72 by respective pivots 78 and 80 and are pivotally attached at their other ends to respective out er ends of the out er two legs or limbs 15 by respective pivots 82 and 84. The pivots 78, 80, 82 and 84 are universal joints to facilitate the degree of freedom of movement required. A latch (not shown) may hol d the slider 72 at its position in which the two cross-members 74 and 76 are substantially collinear. In this way they retain the outer legs or limbs 15 at a desired angle relative to the centre leg 15, and the sheet material or fabric 34 of the tent is maintained at a desired tension.

Wth such a construction, as the frame is changed from its stow condition to its erect condition, the centre leg or limb 15 is raised, and the attachment of the sheet material or fabric 34 of the tent to the frame causes the outer legs or limbs to raise accordingly. Once the centre leg has been snapped into its fully extended position, the cross-members can be brought into alignment with one another by sliding the slider 72 fully to its latched position, so the the sheet material or fabric 34 of the tent is fully stretched, and the canopy (not shown) over the tent entrance is properly s ha ped.

As with the previously described embodiments, the legs or limbs 15 of the second set of legs or limbs of the tent frame are shorter than those legs or limbs 14 of the first set, although this is not evident from the Figures because they only show parts of the legs or limbs 14. With such a construction, the fabric 34 of the tent forms a canopy over an entrance (not shown) of the tent when the frame is in its erected condition.

Numerous variations and modifications may occur to the reader without taking the resulting construction outside the scope of the present invention. For example, there may be only two limbs 15 instead of the three illustrated in the Figures. Furthermore, the limbs 15 do not necessarily curve when the tent is in the unfolded, erect condition. There may be more or fewer limbs 14 than those illustrated.