The present invention relates to a backpack such as a rucksack or the like.

According to the invention, there is provided a backpack comprising a support frame, and a plurality of carrier packs arranged to be demountably mounted on the support frame, each of the carrier packs being provided with mounting formations arranged to be engagable with complementary mounting formations provided on the support frame thereby to secure the respective carrier pack to the support frame, the mounting formations on the support frame comprising a series of mounting formations arranged such that the carrier packs may be mounted in alternative configurations on the frame.

It is preferred that the series of mounting formations on the frame comprise respective rows of mounting formations preferably provided proximate opposed peripheral portions of the support frame.

Advantageously, each carrier pack is provided with at least one pair of mounting formations, each member of the pair preferably being on an opposed end of the carrier pack. Typically, each member of a pair of mounting formations on the carrier pack is engageable with a corresponding member of a pair of mounting formations provided for the support frame. The pair of mounting formations provided for the support frame preferably comprises a member in either row of formations proximate the opposed peripheral portions of the support frame.

Advantageously, each carrier pack is provided with at least two pairs of mounting formations, one member of each pair preferably being provided on an opposed end of the carrier pack.

It is preferred that the mounting formations in each row of mounting formations on the support frame are regularly spaced from adjacent mounting formations in the respective row.

Typically, the mounting formations on the support frame and carrier packs are arranged to be engageable in a "snap-fit" manner. Usually, the engaging mounting formations comprise respective male and female mating formations. Typically, the male formation comprises a pair of resiliently deformable limbs which deform and snap-fit on

engagement with the female formation. Typically, the male formation will be of a plastics material and advantageously provided on the carrier pack.

The mounting formations provided on the support frame may either be formed integrally with the support frame, or, alternatively secured to the support frame. Desirably, the mounting formations provided on the support frame are female formations in the form of slots.

Advantageously, the support frame is formed integrally of plastics or relatively lightweight metal material and preferably comprises a support panel adjacent which the carrier packs are arranged to be mounted. Typically, the support frame is formed with a series of voids or apertures in the panel. Alternatively, the support frame may comprise sub- frame assemblies adjustable relative to one another, preferably telescopically such that the overall dimensions of the support frame can be varied. Advantageously, securing means is provided arranged to securely hold the sub-frame assemblies relative to one another in a desired configuration.

It is preferred that the support frame further comprises a pair of spaced shoulder supports advantageously of plastics and attached to the support frame. Typically, the support frame further comprises a transversely projecting portion such as a shelf or traverse frame element on which at least one (typically the lowermost) of the carrier packs is arranged to be supported. The transversely projecting portion of the support frame is advantageously provided proximate that portion of the frame orientated lowermost in use.

The shoulder supports, and/or the support panel are preferably provided with padding means, such as for example foamed or moulded polyurethane pads arranged to contact respective portions of the body of the user.

It is preferred that the backpack comprises further means for ensuring that the arrangement of carrier packs is securely retained on the frame. Advantageously, the further means comprises a flexible tether such as a strap or belt which is arranged to be connected to the support frame and preferably tensionable to abut and secure the carrier packs on the support frame. Alternatively, or in addition adjacent carrier packs may be arranged to be releasably connected to one another, preferably by means of complementarily engagable male and female formations.

It is preferred that the backpack is provided with means for securing the backpack in position on the back of a user. Desirably, a pair of shoulder straps and

advantageously a girth belt are provided for this purpose. It is preferred that the shoulder straps are arranged to be connectable with the girth belt.

The invention will now be further described in a specific embodiments by way of example only, and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a backpack according to the invention;

Figure 2 is an alternative perspective view of the support frame of the backpack of Figure 1;

Figure 3 is a perspective view, similar to the view of Figure 1, of the backpack of Figures 1 and 2 showing assembly;

Figure 4 is a perspective view of an alternative embodiment of a frame for a backpack according to the invention;

Figures 5 and 6 are perspective views of component parts comprising the backpack frame of Figure 4; and

Figure 7 is a perspective detailed view of a part of the backpack frame of Figures 4 to 6.

Referring to the drawings, there is shown a backpack generally designated 1. Backpack 1 comprises a substantially rigid plastics frame 2 comprising a pair of upright side frame members 3,4, moulded proximate their lowermost extent with transversely projecting support shelf 5. A plastics panel 6 integrally moulded with frame members 3,4, extends between frame members 3,4 adding rigidity to the frame 2.

A pair of curved plastics shoulder supports 7,8 are connected to (typically integrally formed with) the panel 8 and carry support pads 9 of moulded polyurethane foam which provide padding for the shoulders of the user when the backpack is carried.

In the region of its lowermost end, the backpack 1 is provided with a padded lower back support 10 of moulded polyurethane foam which is adhered to the portion of the panel 6 opposite the support shelf 5. The lower back support 10 is provided with a tensionable webbed and buckled girth belt 11 which in use is passed and tightened around the waist or midriff of the user. Webbed shoulder straps 12, 13 extending from respective shoulder supports 7,8 extend downwardly and connect with respective buckles 14, 15 provided on the girth belt 11. Shoulder straps 12, 13 are tensionable by means of sliding members 16, 17 to ensure that the backpack 1 may be held securely in position on the back of the user. Panel 6 is provided with a series of apertures or voids 18 to ensure that the backpack frame

2 itself weighs as little as possible. Apertures or voids 18 also permit air to circulate to the users back.

Running along the respective spines of the side frame members 3,4 are a series of spaced, elongate slots 19. Slots 19 are arranged to receivingly engage respective resilient clips 20 which are provided on carrier packs 21 such that an arrangement of carrier packs 21 may be removable retained on the backpack frame 2.

The carrier packs 21 are flexible and typically of a plastics material such as a nylon weave. Plastics clips 20 are bonded to the outer surround of the respective carrier pack, each clip 20 comprising a pair of arms 20a,20b resiliently deformable toward one another. When arranging a desired arrangement of carrier packs 21 on the frame 2, the arms 20a,20b of the clips 20 are inserted into a respective slot 10 causing the arms 20a,20b to deform inwardly toward one another as this occurs. On complete insertion into a respective slot 19, the arms spring back to their "normal" position such that the engagement of the clip

20 in its respective slot 19 is a "snap-fit".

With carrier packs 21 and a frame 2 as described, it is possible to alter the arrangement of carrier packs 21 in place on the frame by simply removing one or more packs

21 from the frame 2 and replacing with an alternative pack. For example, the configuration shown in Figure 1 comprises four carrier packs of a uniform size, whilst the configuration being assembled in Figure 3 comprises two smaller packs attached to frame 2 with a third pack being attached of twice the smaller size.

A securing webbed strap 22 is connected to the top of the frame 2 such that when the desired arrangement of carrier packs 21 have been assembled on the frame 2 they may be securely held in place. The free end of the securing strap 22 is provided with a clip 23 (similar to the clip 20 described above) which engages in a receiving slot 24 provided in the rim of the support shelf 5.

Referring to Figures 4 to 7, there is shown an alternative embodiment of a backpack frame 30 according to the invention which is adjustable in terms of overall dimensions to suit users of differing build.

Backpack frame 30 comprises sub frame assemblies 31 and 32, best shown in Figures 5 and 6 respectively. Sub frame assembly 31 comprises a pair of upright tubular side frame members 33,34 provided with slots 19 for receiving the clips 20 of packs (not shown) in a similar manner to the embodiment described above. Side frame members 33,34

are connected at their lowermost extent by a transverse package support bar 35. An upper transverse bar 36 extends between the upper portions of side frame members 33,34 having struts 36a,36b received telescopically in respective side frame members 33,34.

A pair of inner side frame members 37,38 extend downwardly adjacent locating guides for respective frame members 40,41 provided on sub-frame assembly 32.

Back pack frame 30 is assembled by sliding frame members 40,41 (provided on sub assembly 32) over inner side frame members 37,38 until the respective assemblies 31,32 are in the desired configuration suited to a particular user. Clamps 42,43 are then tightened to lock the respective assemblies 31 ,32 in their desired relative orientation. In this way, the overall dimensions of back pack frame 30 are adjustable. Webbing straps 44,45 serve to retain the shoulder support moulding 46 and lower back support 10 relative to one another when the backpack is in use.

As an alternative to providing the slots 19 integrally in the side frame members 33,34 or 3,4, slotted female clip formations may be attached along the length of the side frame members at the required spacing by means of short lengths of webbing.