RUCKSACK HIP PAD

Abstract: Rucksack hip pads (21, 22) are each provided with recessed regions (13) in the surface which contacts the user's body and extending to the lower edge thereof, these recessed regions being configured to fit onto the respective hips of the user. The upper edge (15) of the recess (13) transmits the load downwardly to the pelvic girdle, thereby reducing inward compression thereof. The pads are produced of foamed plastics and may be moulded with integral recesses. Stiffening may be provided in the non-recessed parts of the pads, conveniently as a web fixed to or embedded in the opposite surface. A combined lumbar and hip pad may alternatively be provided, having symmetrical recesses for both hips.

Description: RUCKSACK HIP PAD TECHNICAL FIELD This invention relates to a rucksack hip pad. Modern large capacity rucksacks generally comprise a fabric sack, a supportive frame comprising at least one substantially rigid vertical member mounted at the rear of the sack, a harness comprising shoulder pads, (often conjoined in the scapular region) mounted on the frame, and associated shoulder straps, a lumbar pad mounted to the sack or frame centrally, below the shoulder pads, and, at each side of the lumbar pads, respectively hip pads,, which merge into the straps and/connectors forming the hip belt. A load within the sack is most efficiently and comfortably carried when a major proportion thereof is transmitted to the hips of the user via the hip pads, with the shoulder pads serving primarily a stabilizing function and transmitting only a minor proportion of load to the shoulders of the user. In this respect the front shoulder region especially is anatomically sensitive and subject to discomfort, and the entire shoulder region is prone to injury if overstressed. . BACKGROUND ART " Hitherto, hip pads have usually been formed of flat pieces of foamed plastics material cut out from large sheets of material, and covered by a fabric envelope. In some cases the foamed plastics core has been shaped so that in use the hip pads and lumbar pad together take up a frusto-conical configuration, generally adapted to fit around the hip region of the user. In some cases stiffening has been provided, such as polypropylene plates onto which the hip pad cores have been mounted. In some cases there has been through stitching to give a quilted effect along with some compression and hence stiffening of the foamed plastics. In general, however, despite these refinements the load has continued to be transmitted primarily by pressure directed inwardly of the pelvic region of the user. The resultant compression at the top of the iliac crest of the user is undesirable, and can result in injury and/or serve discomfort in the case of heavy loads. It is an object of the present invention to provide an improved hip pad construction whereby transmission of load downwards onto the pelvic girdle is enhanced while inward compression is reduced compared to previously known arrangements. DISCLOSURE OF THE INVENTION According to one aspect of the present invention a rucksack hip pad comprises a core of foamed plastics material which has, in its surface which in use contacts a user's body, a recessed region extending to the lower edge thereof and configured to fit onto a hip of a user. In this respect, the upper edge of the recessed region will seat onto the iliac crest and will serve to transmit load thereto from above. According to another aspect of the invention an integral hip and lumbar pad for a rucksack comprises a core of foamed plastics material which has, in its surface which in use contacts a user's body, symmetrically arranged recessed regions, each extending to the lower edge thereof and configured to fit onto respective hips of the user. Pads according to either aspect are suitably made of closed cell polyethylene foam, of appropriate density for a reasonable degree of inherent stiffness. However, other foamed materials are possible, such as polyurethane. In either case. the or each recessed region may be cut out, or more favourably from a manufacturing point of view, the foamed material may be moulded with an integral recess or recesses and any other suitable contouring. In this respect, it should be noted that the or each recessed region will generally be of reduced thickness compared to the remainder of the core. In a particularly advantageous development, the hip pad or the combined hip and lumbar pad of the ' invention may have stiffening means extending adjacent the upper edge of the core. The purpose of this stiffening is to act in cantilever manner and transmit load directly from the rucksack frame, to which the rear edge margin of the pad is connected in use, to the top of the pelvis- of the user. This stiffening means may comprise a stiff web or plate, e.g. polypropylene, fixed to the surface of the. pad remote from contact with the user's body (i.e. the opposite surface of the recessed region). In the case of separate hip pads for each side of the body, two types of practical embodiment are envisaged. On the one hand the recessed region to fit the hip of the user may extend to the front edge of the pad, such that hips of users of different body size can locate at different points within this longitudinally enlarged recess. Such a pad can be non-ad ustably attached to the rucksack, since when fixed in position it will still accommodate different hip positions of different users. With such an embodiment, and with the pad formed by moulding, the stiffening means may advantageously be moulded integrally therewith, or embedded within the foam body. As an alternative to a separate web of stiff material, the stiffening could be achieved by a much higher density region of foamed plastics, or a different composition of foamed plastics. On the other hand the recessed region may be of fixed longitudinal extent, effectively an inverted cup shape, and the position of the foamed plastics core may be longitudinally (i.e. sidewise with respect to the rucksack and the user) adjustable with respect to the stiffening means. In such a case, the stiffening will obviously be formed separate from the core and the adjustability may suitably be achieved by a row of apertures in the stiffening and studs or similar fastenings on the pad, or projecting through corresponding apertures in the pad, which are interengageable with selected ones of the row of apertures in the stiffening. In the case of a combined hip and lumbar pad there will obviously be no possibility of adjustment of the position of the recesses during the life of the rucksack. These recesses should, accordingly, extend to the respective ends of the pad, or close to the ends to allow for accommodation of hips of users of different stature. The stiffening may be provided as outlined in respect of the first mentioned single hip type of pad. Obviously, such a one piece pad has advantages in obviating several assembly steps in production of rucksacks. It will be appreciated that a range of different standards of hip pad or combined hip and lumbar pad can be produced, all conforming to the invention, but comprising different sizes, different colours, different foamed plastics materials, or at least different densities thereof (hence variations in softness) and different types, sizes etc. of stiffening means, for example to suit male or female rucksack users, users of different body size, and rucksacks of different capacity (loading). Usually such pads will each be covered by fabric, which is stitched therearound or adhered thereto, as that gives best appearance for a commerical product. The fabric cover is not, however, functionally essential, so could be omitted. Further aspects of the invention are, of course, rucksacks as defined in the introduction having either two hip pads, each with a recessed region configured to fit the user's hips, as discussed in the foregoing, or having a combined hip and lumbar pad provided with two such recessed regions. BRIEF DESCRIPTION OF THE DRAWINGS Several specific embodiments of pads in accordance with the invention and one specific embodiment of a rucksack incorporating one type of these will now be briefly described, by way of illustration only, with reference to the accompanying drawings, in which: Fig. 1 is a rear view of a rucksack incorporating one type of hip pad in accordance with the invention, but with the hip belt parts broken away; Fig. 2 is an enlarged fragmentary perspective view of the surface which contacts the user's body of one hip pad as shown in Fig. 1; Fig. 3 is a similar view of the surface remote from the user's body of the hip pad shown in Fig. 2; Fig. 4 is a view comparable with Fig. 2 of a second type of hip pad in accordance with the invention; Fig. 5 is a view comparable with Fig. 3 of said second type of pad; Fig. 6 is a view of the surface which contacts a user's body of an integral hip and lumbar pad in accordance with the invention, the attached hip belt being broke away; Fig. 7 is a corresponding view of the surface remote from the user's body of the pad shown in Fig. 6; and Fig. 8 is a view, comparable to Fig. 7, of a modified embodiment of integral hip and lumbar pad in accordance with the invention. BEST MODES OF CARRYING OUT INVENTION With reference firstly to Figs. 2 and 3, a first type of hip pad in accordance with the invention comprises a generally quadrangular core 10 of foamed polyethylene of suitable stiffness. This tapers so that its rear end 11 in use is broader, while its front end 12 is narrower. It is longer in the front to rear direction than the top to bottom direction. As shown in Fig. 2, on the surface of the core 10 designed to contact the user there is a recessed region 13 which extends to the front edge 12 and the lower edge 14. The upper and rear edges 15, 16 defining the recess are champfered (rounded), and they also merge into each other via a curve, and these constitute ledges which fit onto the hip of the user. Via the upper edge 15 in particular forces are transmitted downwards to the pelvic girdle of the user. The recessed region 13 may be moulded in, or cut out, depending on the method of manufacture of the pad. In this example the recessed region is thinner than the remainder of the core 10. As shown in Fig. 3, a stiffening plate 17, e.g. of polypropylene is fixed to the opposite side of the foamed plastics core 10. This plate 17 is roughly L shaped and extends along the upper and rear edge margins of the foamed plastics, generally corresponding to the non-recessed region of the other surface. Also attached on the same surface as .the plate 17, is a strip of webbing 18 which extends to form one part of the hip belt, for fastening around the body of the user. A pair of looped elements 19 are also attached at the rear edge of the plate 17, whereby the hip pad may be mounted onto a vertical frame member 20 (see Fig. 1) of the rucksack. If the foamed plastics is moulded, any or all of the plate 17, the webbing 18 and the connection elements 19 may be integrally connected in the moulding process. If the foamed plastics is cut out, these components are simply attached e.g. by gluing or fastening means. A fabric envelope (not shown) may optionally cover at least the foamed plastics core 10 and the plate 17, with the webbing 18 and connectors 19 possibly attached to the outside of the fabric, or projecting therethrough. Fig. 1 merely shows the relative positioning of two such hip pads, designated generally by reference numerals 21 and 22, in a fully assembled rucksack. The rucksack comprises a fabric sack 23, a supporting frame constituted by parallel vertical bars 20 mounted at the rear of the sack, shoulder pads 24 joined in the scapular region 25, where they are slidably mounted on the respective bars 20, and associated shoulder straps 26, and top straps 27. Directly below the scapular pad region 25, a lumbar pad 28 is mounted on the sack, between the bars 20. The respective hip pads 21 are mounted symmetrically, at each side of this lumbar pad 28, the respective bars 20 extending through the rear looped elements 19. The stiffening plates 17 act in cantilever manner to transmit the load of the sack directly from the frame bars 20 to the hips of the user. An alternative style of hip pad is shown in Figs. 4 and 5, but the same reference numerals are used for corresponding components. Here the L-shaped stiffening plate 17 and the foamed plastics core 10 are separate components. The recess 13 of the core does not extend right to the front edge 12 of the core, but is roughly inverted cup shaped and is dimensioned more precisely to the configuration of the pelvis of a user of a certain stature. This core (hence the recess 13 therein) is then adjustable sidewise relative to its supportive stiffening 17. In this particular embodiment the stiffening 17 is shown with a longitudinal row of apertures 30, and core pad 10 is provided with spaced studs 31 which engaged with any selected spaced pair of such apertures 30. Other fastening means may, however, be employed in other embodiments of this type. In practise it is envisaged that with this style of hip pad possibly three different sizes of recess may be needed to cater for different statures of users. Other body size differences (i.e. differences in distance between the lumbar region and the iliac crest) are accommodated simply by the sidewise adjustment of the foamed plastics cores. Figs. 6 and 7 show an all-in-one hip and lumbar pad in which the same general principle of provision of recesses to fit over the pelvis are embodied. Specifically this particular example comprises a moulded foamed polyethylene band 50 which is integrally configured to have, on a surface intended to contact the user's body, recessed regions 33 which merge into each other in the central lumbar region 38, and extend to the ends and the lower edge of the band 50, and protruding regions 35 thereabove as well as a central protrusion 36 adjacent the upper edge of this band. This surface contour is designed to fit closely to the body contour of a user. A relatively stiffer yet flexible sheet of polypropylene 51, of the same peripheral shape, is attached to the reverse surface of the foamed plstics 50, as shown in Fig. 7. This may be accomplished by adhesive, and an edging strip 32 of fabric provides a neat finish. Slotted elements 40 for mounting on frame bars 20 (see Fig. 1) of a rucksack are fastened to the sheet 51. The two webbing parts of a hip belt strap 39 are also connected to the ends of the pad, being conveniently held between the plastics band 50 and the backing sheet 51. Fig. 8 shows a variant wherein the stiff backing sheet 51 is cut away opposite to the recessed regions 33 so that only the upper and central regions are reinforced. In this case the hip belt strap 39 is in one piece and extends between the foamed plastics and the stiff sheet 51. Numerous variations are possible within the scope of the invention, particularly in the manner of attachment of the hip pads 21, 22, or their stiffening means or the combined hip and lumbar pad to a rucksack, in the form of pad stiffening, and in the method of production of the pads.

Claims: CLAIMS 1. A rucksack hip pad comprising a core (10) of foamed plastics material which has, in its surface which in use contacts a user's body, a recesses region (13) extending to the lower edge thereof and configured to fit onto a hip of a user. 2. An integral hip and lumbar pad for a rucksack comprising a core (50) of foamed plastics material which has, in its surface which in use contacts a user's body, symmetrically arranged recessed regions (33), each extending to the lower edge thereof and configured to fit onto respective hips of the user (Figs. 6 to 8). 3. A pad according to claim 1 or 2 wherein the core is made of closed cell polyethylene foam. 4. A pad according to claim 1, 2 or 3 wherein the core of foamed material is produced by moulding with an integrally formed recessed region (13), or, respectively, with two integrally formed recessed regions (33). 5. A pad according to any preceding claim wherein the or each recessed region (13,33) is of reduced thickness compared to the remainder of the core (10,50). 6. A pad according to any preceding claim having a web (17,51) of stiffening material attached to the surface of the core (10,50) which in use is remote from the user's body. 7. A pad according to any preceding claim having stiffening means (17,51) extending adjacent the upper edge of the core (10,50). 8. A pad according to claim 1, and claim 6 or 7 wherein the stiffening material or the stiffening means (17) is approximately L-shaped in form (Figs. 3 and 5). 9. A pad according to any of claims 6, 7 or 8 wherein the stiffening material or stiffening means (17,51) comprises a contoured sheet of polypropylene, fixed to the surface of the core (10,50) remote from .contact with the user's body. 10. A pad according to claims 4 and 9 wherein the core (10.50) formed by moulding and the stiffening plate (17.51) is moulded integrally therewith, or embedded within the foam body. 11. " A pad according to any of claims 6, 7 or 8 wherein the stiffening material or stiffening means consists of a much higher density region of foamed plastics, or a different composition of foamed plastics. 12. A pad according to any of claims 6 to 11 wherein the stiffening material or stiffening means is only provided in or on regions of the core other than the recessed regions and the regions of the opposing surface corresponding thereto. 13. A pad according to any preceding claim where the or each recessed region extends- to the front edge of the core. 14. A pad according to claim 1 and 6 or 7 wherein the recessed region is of fixed longitudinal extent, effectively an inverted cup shape, and the position of the foamed plastics core (10) is longitudinally (i.e. sidewise with respect to the rucksack and the user) adjustable with respect ot the stiffening material or stiffening means (17) (Figs. 4 and 5). 15. A pad according to claim.14 wherein longitudinal adjustment of the core relative to the stiffening is achieved by a row of apertures (30) in the stiffening (17) and studs (31) or similar fastenings provided on the core, or projecting through corresponding apertures in the core, which are interengageable with selected ones of the row of apertures in the stiffening. 16. A pad according to any preceding claim and provided with a fabric cover which is stitched therearound or adhered thereto. 17. A rucksack having two hip pads (21,22) each with a recessed region (13) configured to fit the user's- hips, as claimed in claim 1. 18. A rucksack having a combined hip and lumbar pad with two recessed regions configured to fit the user's hips, as claimed in claim 2.

Inventors: FARNWORTH MICHAEL ADRIAN, PARSONS MICHAEL CHARLES, FARNWORTH, MICHAEL, ADRIAN, PARSONS, MICHAEL, CHARLES
Applicants: KARRIMOR INT LTD, KARRIMOR INTERNATIONAL LIMITED
Application year: 1990
Main classification: A45F3
IPC codes: A45F3