Tramper's pack;flexible connection secures hip belt to pack sac

COMPLETE SPECIFICATION

Date: 30.8.1982 ''Improvements in Tramper's Packs''

WE, MACPAC PRODUCTS (N.Z.) LIMITED, a New Zealand Company, of 208 Oxford Terrace, Christchurch, New Zealand, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:1

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BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to improvements in tramper's packs. A tramper's pack comprises a sac in which equipment may be carried, the sac being unframed or mounted on an external or internal frame, and a shoulder harness secured to sac by means of which the sac is supported on the wearer's back. Carrying a heavy load supported only from the shoulders can lead to backache or even to back damage, so many modern packs include a hip-belt connected at or close to the base of the sac, to transfer some of the load from the shoulders to the hips. However, although using a hip-belt alleviates the loading on the back, the hip-belt itself causes problems to the wearer, due to the way in which the human body moves when walking, as illustrated in Figs. 1-4 of the accompanying drawings .

When a human being walks, he leans backwards and forwards with each step (Fig.l) and from side to side with each double step (Fig.2). As he leans to the supporting side when taking a step the torso compresses and extends on the stepping side (Fig.3):- this means that, viewing the person from the front, the person's hips pivot up and down around an imaginary centre line (indicated in broken lines in Fig.3). This is termed

201 75 'up and down' movement in the present specification. In addition, as shown in Fig. 4., the person's hips move with his legs, but his torso and arms swing in the opposite direction, with the body pivoting at the waist. In Fig.4, a line through the shoulders is indicated by line S-S and a line through the hips is indicated by line H-H. As shown in Fig.4, there is a considerable relative rotation between the shoulders (line S-S) and the hips (line H-H) with each step. This is termed 'twisting' movement in the present specification.

Also, when a human being bends or steps up, his back extends:- the further the person leans forwards, the longer his back becomes. This extension of the back is in a curved plane, following the natural curve of the back.

Because of the above described movements , a hip belt which is rigidly secured to the pack, and which therefore moves with the pack, is very uncomfortable for the wearer, because the hip belt is constantly rubbing against the wearer due to the relative movements of different parts of the wearer's body when walking. The hip belt cannot be loosened to prevent this rubbing, because the belt must fit snugly to transmit load to the wearer's pelvic girdle and relieve the load on his back. Fig.5 of the accompanying drawings shows, in diagrammatic form, the effect of a person wearing a pack with a

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rigidly-secured hip-belt bending forwards:- the back extension raises the pack and lifts the hip-belt from the hips, applying uncomfortable pressure across the front of the lower abdomen (arrow P).

DESCRIPTION OF THE PRIOR ART

Known designs of hip-belt either are secured rigidly to the pack or allow a very little relative movement, in one plane only, between the pack and the hipbelt .

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a tramper's pack in which the hip-belt is secured to the sac in such a way as to provide a loadtransmitting connection which, when the sac is secured to the wearer's back and the hip-belt secured around the wearer’s hips, permits relative movement between the wearer's back and hips, (and hence between the sac and the hip-belt) in at least three directions:- twisting, up and down, and in a curved plane parallel to the plane of the wearer's back.

The present invention provides a tramper's pack incorporating a sac and a hip-belt secured to the sac by a load-transmitting connection comprising a flexible

- 4 20175 member secured between substantially the midpoint of the width of the back of the sac and substantially the midpoint of the length of the hip-belt, said flexible member being dimensioned and arranged so as to permit relative movement between the hip-belt and the sac in at least three directions:- twisting, up and down and in a curved plane parallel to the plane of the wearer's back.

Said flexible member may comprise e.g. a length of webbing or a first length of webbing secured between the hip-belt and one side of a buckle and a second length of webbing secured between the sac and the other side of the buckle.

BRIEF DESCRIPTION OF THE DRAWING

By way of example only, a preferred embodiment of the present invention is described in detail with reference to Figs. 6 and 7 of the accompanying drawings, in which: Fig.6 is a sketch perspective view of the lower part of a tramper's pack in accordance with the present invention, with the hip-belt turned downwards, away from the pack; and

Fig.7 is a diagram showing said pack in use.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing, a tramper's pack 2 comprises a sac 3, only the lower part of which is shown, and a shoulder harness of known type (not illustrated).

A hip-belt 5 is secured to the back of the sac (i.e. to that surface of the sac which in use faces the back of the wearer).

The hip-belt 5 comprises three integrally formed padded sections 6, 7, 8, the central section 6 contacting the wearer’s back in use, and each outer section 7 and 8 being shaped at its free end to cup the wearer’s hip joint The sections 6, 7 and 8 are covered by a continuous cover of waterproof material, but the padding for each section is formed separately, so that the belt can hinge at the joints 9 between the sections of padding. The free ends of the outer sections 7 and 8 terminate just beyond the wearer's hip-joints, and the belt is fastened by a catch or buckle (not shown) of known type secured to the outer sections 7, 8, by adjustable lengths of webbing 10. In use, the hip-belt is fastened around the wearer's hips and the webbing 10 is adjusted in length until the belt fits snugly.

The hip-belt 5 is secured to the remainder of the pack by a single central load-transmitting connection 12:— a short length of webbing 13 is passed through one side

2.01 75fi of a buckle 14 and the ends of the webbing 13 are stitched to the centre of the central section 6 of the hip-belt, on the side of the belt facing the sac. The other side of the buckle 14 is connected by a second length of webbing 15 to a point on the centre-line of the back of the sac, at or adjacent the end of the back panel of the sac. One end of the webbing 15 is secured to the sac, and the other end of the webbing 15 is passed through the other side of the buckle 14, slid under a retainer 20 secured across the sac, and fastened to a supporting strap 21 secured to the sac. To fit the pack exactly to different wearers, the webbing 15 may be adjusted in length by altering the point at which the webbing 15 is secured to the strap 21. The widths of the buckle 14 and of the webbing 13, 15, are very much less than the length of the central section 6, for example the length of the central section 6 may be 21 cm, and the width of the buckle and webbing about 4.5 cm.

The above-described connection 12 permits movement of the hip-belt relative to the remainder of the pack in three directions:- up and down movement (Fig.3 and arrow A in Fig.6), twisting movement (Fig.4 and arrow B of Fig. 6) and movement in a curved plane parallel to the curve of the wearer's back (Fig.5 and arrow C of Fig.6). Fig.7 shows said movement in a curved plane:- in Fig.7a, the wearer is standing straight, and the connection 12 transmits load from the sac 3 to the hip-belt 5. When the wearer leans forward (Fig.7b) the connection 12 accommodates the movement of the sac 3 with the wearer's back, without displacing or pulling at the hip-belt 5.

The hip-belt is also connected to the sac by a pair of stabilizer straps 18, each of which is secured at one end to the outer surface (i.e. the surface facing the pack) of the corresponding outer section 7 or 8 of the belt, and at the other end is connected to a buckle 19 secured to the side of the sac at a point slightly above the end of the back panel. For normal tramping use, the stabilizer straps 18 are left loose, so that they do not restrict the movement of the sac relative to the wearer unless the sac swings well away from the wearer. However, if it becomes necessary to secure the sac rigidly to the wearer (e.g. for downhill skiing) then the straps 18 are tightened until virtually no relative movement between the pack and the wearer can occur.

It will be appreciated that the webbing-and-buckle connection between the central section 6 of the belt and the sac could be replaced by any equivalent load-transmitting connection, e.g. a strip of webbing secured between the back panel of the sac and the centre of the section 6 of the belt, said strip being long enough to permit bending and flexing of the strip and so permit the relative movements between sac and belt described above.

M

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