The present invention relates to a backpack, and particularly but not exclusively to a children's backpack providing a waterproof storage volume.

Background Backpacks are widely known and used for transporting equipment or personal items. A typical backpack comprises at least one main storage volume that can be closed by a releasable closure, and at least one shoulder strap to allow the backpack to be comfortably carried on the back of a user. Backpacks are commonly used by children of school age for carrying school materials, including academic materials and sports or games kit, to and from school. The market for children's backpacks is well established and includes many ranges featuring characters and decoration designed to appeal to younger users.

A common problem with standard backpacks arises when they are required to operate in wet environments. This may include for example the carrying of wet items, such as swimming kit, or the use of a backpack in a potentially very wet environment such as at a beach or on a boat. For adult consumers, the market includes products designed specifically for these circumstances, usually known as dry bags. A typical dry bag is made from waterproof material with specialist waterproof seams and a main opening that is closed by a roll down waterproof seal. These seals include a collar of waterproof material, opposed sides of which are brought into contact with each other and then the double thickness of material is rolled or folded upon itself a number of times. This rolled seal is then curved upon itself and opposed ends are connected using releasable clips. The clipped ends of the seal are commonly used as a handle for transporting the dry bag. An example dry bag 2 is illustrated at Figure 1 , in which the main storage volume 4, rolled seal 6 and releasable clips 8 may all be seen. The ends of the seal 6 and clips 8 may also be seen to constitute the handle 10 by which the dry bag is carried.

While dry bags fulfil the adult need for waterproof transport of items and equipment, there remains a need for waterproof carrying solutions for younger users including children of school age.

Summary of Invention According to the present invention, there is provided a backpack for use by a child, the backpack comprising a storage volume and a closure operable to seal the storage volume, wherein the closure comprises a collar of flexible material operable to be folded at least twice upon itself and cooperating fastening elements mounted on opposing sides of the collar for releasable engagement with one another, wherein the fastening elements are constructed so as to release one another under tension exceeding a predetermined threshold value of between 15N and 30N.

The threshold value may be selected according to toy and nursery safety standards applicable in countries where the invention would be marketed. Thus, for example, backpacks designed and sized for very young users of the age 3 and up may be comprise fastening elements constructed to release one another at a threshold value that is considerably lower than that selected for backpacks designed for older users. According to one embodiment, the threshold value may be 20N to be less than the current regulations in Europe under EN71 for strangulation breakaway strength. According to another embodiment the threshold value may be 25N.

The fastening elements may further comprise a user operated release mechanism and may be mounted adjacent a rim of the collar.

A first of the fastening elements may comprise a housing having an engagement opening and a second of the fastening elements may comprise a projection having an engagement shoulder which may be operable to engage the engagement opening.

The engagement shoulder and/or the engagement opening may comprise a chamfer. The storage volume may be defined by a bag, and the collar of flexible material may comprise a continuation of the bag.

The bag is formed from substantially waterproof material and may for example comprise at least one waterproof seam.

The backpack may comprise at least one shoulder strap and according to one embodiment may comprise a pair of shoulder straps.

The backpack may further comprise a back pad, on which the at least one shoulder strap may be mounted. The back pad may for example be padded and may provide additional rigidity to the backpack and/or additional comfort for a user.

In one example, the backpack further comprises a third fastening element mounted adjacent a base of the collar, wherein each of the first and second fastening elements cooperates with the third fastening element for releasable engagement with the third fastening element. By mounting the third fastening element on the backpack, the loop diameter is cut in half and thereby reduces the length so that a child could fasten around their neck.

The third fastening element may comprise at least two engagement openings and the first and second fastening elements may each comprise projections having engagement shoulders which may be operable to engage a respective engagement opening on the third fastening element.

The three fastening elements may further comprise a user operated release mechanism.

The first, second and third fastening elements may be constructed to release one another under tension exceeding the threshold value of between 15N and 30N.

According to one embodiment, the engagement shoulders and/or engagement openings may comprise chamfers.

The third fastening element may be mounted on the bag.

The third fastening element may be mounted on the back pad. Brief Description of the Drawings

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the following drawings, in which:-

Figure 1 illustrates a conventional dry bag; Figure 2 illustrates a first embodiment of backpack in a partially open configuration;

Figure 3 illustrates the back pack of Figure 2 in a closed configuration;

Figure 4 illustrates a bag component of the backpack of Figure 2

Figure 5 illustrates a first embodiment of clip in an open configuration;

Figure 6 illustrates the clip of Figure 5 in a closed configuration; Figure 7 illustrates a second embodiment of clip in an open configuration; Figure 8 illustrates the clip of Figure 7 in a closed configuration;

Figure 9 a second embodiment of backpack in a closed configuration;

Figure 10 illustrates another embodiment of clip in an open configuration; and

Figure 11 illustrates the clip of Figure 10 in a closed configuration. Detailed Description of Embodiments

Embodiments of a backpack according to the present invention will now be described with reference to the accompanying drawings.

Referring initially to Figures 2 and 3, a first embodiment of backpack 20 according to the present invention comprises a bag 22 defining a storage volume 24, a closure 26, back pad 28 and shoulder straps 30, 32. The bag 22 is mounted on the back pad 28, the back pad 28 providing additional rigidity to the bag and also providing comfort to the wearer, by cushioning the back of the wearer against the contents of the bag 22.

The bag 22 is formed from a tough waterproof material such as a synthetic nylon which may be treated or coated for enhanced performance. With reference also to Figure 4, the closure 26 comprises a collar 34 of flexible material which, according to the present embodiment, is formed continuously with the bag 22. The bag 22 is mounted on the back pad 28 such that the collar 34 projects above the upper limit of the back pad 28 and shoulder straps 30, 32. The collar 34 may be reinforced at its rim 36 for example by a strip of reinforcing material 38 extending around the rim of the collar 34. The reinforcing strip 38 may impart additional rigidity to the material of the collar 34, assisting with the necessary folding or rolling action as described in further detail below. The closure 26 further comprises first and second fastening elements 40, 42 which are mounted at opposed sides of the collar 34, and may for example be mounted substantially adjacent the rim 36 of the collar 34. According to one embodiment, the fastening elements 40, 42 may be mounted via the reinforcing strip 38 in order to provide additional security of fixation for the fastening elements 40, 42. Detail of the fastening elements is discussed below with reference to Figures 5 to 8.

Referring again to Figures 2 and 3, the shoulder straps 30, 32 are mounted via the pack pad 28, with upper mounting locations for the shoulder straps being substantially adjacent the upper limit of the back pad 28. The shoulder straps 30, 32 may be padded for additional comfort and may comprise auxiliary pockets, straps 44, hooks or other elements to allow for storage or carrying of small items such as a watch, sunglasses, swimming goggles etc.

In use, the contents of the storage volume 24 are sealed against ingress of water or other liquids by correct engagement of the closure 26. This is effected by first bringing the sides of the collar 324 into contact with one another, the fastening elements 40, 42 projecting sideways from the now double layer thickness of collar 34. The double thickness collar 34 is then rolled or folded upon itself, preferably a minimum of three times. The reinforced strip 38 may assist with this folding or rolling motion, defining the first fold line at the lower edge 39 of the strip 38. The rolled collar 34 thus forms a linear seal having fastening elements 40, 42 projecting from each end. These ends are then curved around to approach one another, as illustrated in Figure 2, and the fastening elements 40, 42 are engaged, as illustrated in Figure 3. In this manner, the collar is held securely and prevented from unrolling; ensuring the seal provided by the folded collar 34 remains watertight.

The loop is defined by the diameter of the bag opening and for child use this should be kept wide as to facilitate easy packing through the opening. However loops create strangulation hazards which present serious danger to children. The addition of a break away tension allows the loop to be broken at a safe tension should a child attach the loop around their neck, eradicating the risk of suffocate. This risk is further enhanced should the bag get caught on something while wearing around the neck. However in the adult market it is desirable to have a no break away clip to keep contents dry at all times, especially during extreme activities.

Referring now to Figures 5 and 6, the first and second fastening elements 40, 42 can be seen in greater detail. The first fastening element 40 comprises a housing 46 having two engagement openings 48, 50. The second fastening element 42 comprises three prongs or projections extending substantially parallel and including a central projection 52 and side projections 54. A single side projection is described below but it will be appreciated that corresponding features are found on the other side projection. The side projection 54 comprises an engagement shoulder 56 formed on an outer surface of the projection and shaped to engage a base of the corresponding engagement opening 48 on the housing of the first fastening element 40. The engagement shoulder may form part of an engagement ridge 55 that provides a gently tapered approach shoulder 58 facing towards the housing and the more heavily angled engagement shoulder 56 facing away from the housing. The fastening elements are engaged by inserting the projections of the second fastening element 42 into the housing of the first fastening element 40. The side projections 54 ride into the housing along the gently tapering approach shoulders 58 before the side projections snap into place as the engagement shoulders 56 snap into engagement with the openings 48, 50. In order to release the fastening elements, it is sufficient to apply inward pressure to the two engagement ridges 55, disengaging the engagement shoulders 56 and allowing the fastening elements to be pulled apart.

Referring again to a single side projection, the engagement shoulder 56 does not form a right angle with the axis of the projection 54 but rather comprises a chamfer. The shoulder thus demonstrates a tapered profile, more heavily angled than the approach shoulder 58 but falling short of the conventional right angle employed in known fastening elements. This angled profile of the engagement shoulder 56 provides a connection between the engagement shoulder 56 and engagement opening 48 that is less resistant to tension forces than would be the case with a right angled shoulder. The profiled engagement shoulder thus provides an emergency release mechanism, by which the fastening elements 40, 42 will release one another at tensions exceeding a predetermined threshold value. This threshold value is dictated by the angle at which the engagement shoulder extends relative to the portion of the housing 46 that defines the engagement opening 48 with which it is engaged. The desired threshold value, and hence required angle of engagement shoulder, may be selected according to the average strength of a likely user, ensuring that in the event of an emergency, the user may pull the fastening elements apart, or indeed the fastening elements will simply disengage should the tension applied to them exceed the threshold value. This emergency release mechanism is particularly important in the case of children's backpacks, where the possibility exists of a strangulation hazard arising from the loop formed by the seal and fastening elements. According to the present invention, should such a situation arise, the fastening elements will either release automatically under the applied tension, or the child may pull the fastening elements apart, without needing to locate the engagement ridges 55 and apply the required inward pressure as well as tension.

As discussed above, the threshold tension value at which the fastening elements disengage may be selected according to the average strength of the target user, and thus backpacks designed and sized for very young users may be comprise fastening elements constructed to release one another at a threshold value that is considerably lower than that selected for backpacks designed for older users. The threshold value may for example be between 15N and 30N. According to one embodiment, the threshold value may be 20N. According to another embodiment the threshold value may be 25N. Referring now to Figures 7 and 8, an alternative embodiment of fastening elements 140, 142 is illustrated, in which the engagement ridge 155, comprising engagement shoulder 156 and approach shoulder 158, is formed on the central projection 152 of the second fastening element 142. A corresponding engagement opening 148 is formed on the housing 146 of the first fastening element 140. This embodiment of fastening element functions substantially as described above, inward pressure on the engagement ridge 155 allowing disengagement of the fastening elements. Similarly, the engagement shoulder 156 is chamfered to allow release of the fastening elements at tensions exceeding a threshold value. Referring now to Figures 9 to 11 , a second embodiment of backpack 60 according to the present invention also comprises a bag 62 defining a storage volume 64, a closure 66, back pad 68 and shoulder straps 70, 72. The bag 62 is mounted on the back pad 68 as in the first embodiment. The closure 66 operates substantially as described above with reference to the first embodiment, a collar 74 of flexible material being folded upon itself to form a seal and then the ends curved towards one another and fastened via fastening elements. In contrast to the first embodiment, the first and second fastening elements 80, 82 of the second embodiment of back pack 60 each comprise central and side projections, as described above with respect to the second fastening element 42 of the first embodiment. The side projections comprise engagement ridges 95 having engagement shoulders 96. Each of the first and second fastening elements 80, 82 is operable to be received in a dedicated double housing formed on a third fastening element 100. The third fastening element 100 is mounted via a loop 102 on the back pad 68 at an upper limit of the back pad, and hence immediately adjacent the base of the collar 74, where the collar 74 extends from the rest of the bag 62 above the back pad 68 and shoulder straps 70, 72. The third fastening element 100 is illustrated in detail in Figures 9 and 10 and comprises a double housing 86, allowing entry from two opposed sides of the housing and comprising double sized engagement openings 88, 90. Each engagement opening 88, 90 is of sufficient size to admit two engagement ridges 95, one from each of the first and second fastening elements 80, 82. The backpack 60 of the second embodiment is sealed by folding the collar 74 as described above and fastening the ends of the folded or rolled collar together via the first, second and third fastening elements 80, 82, 100. In this manner, the creation of a loop that might represent a strangulation hazard is avoided as the third fastening element is both essential for joining the ends of the seal, and so forming the loop, and also securely anchors the otherwise free part of the loop to the back pad 68. The anchored loop cannot therefore be closed around a child's neck. According to one embodiment, the engagement shoulders 96 of the first and second fastening elements 80, 82 may comprise chamfers as described with reference to the first embodiment, thus providing the additional safety feature of an emergency release mechanism. Although not illustrated, the first and second fastening elements 80, 82 of the second embodiment may also take the form illustrated in Figures 7 and 8, with the third fastening element comprising an appropriate double engagement opening. It will also be appreciated that any other of the features described in relation to the first embodiment of backpack 20 may be incorporated into the second embodiment of backpack 60, and vice versa.