Pack and frame for pack

Abstract

A pack which includes a sac, an internal frame for the sac, a shoulder harness and a hip belt; the frame includes a pair of spaced flexible rods positioned one on each side of the frame so as to extend down at least the lower part of the length of each side of the sac; tensioning means are secured between each flexible rod at or adjacent the end of said flexible rod, and an adjacent portion of the hip belt; each said tensioning means being adapted to move the corresponding flexible rod so as to bow and tension said rod and provide a relatively rigid weight transmitting connection between said rod and the corresponding portion of the hip belt; the arrangement being such that said movement of said flexible rods tends to lift the frame and the pack, decreasing the loading on the shoulder harness and increasing the loading on the belt.

Description

TECHNICAL FIELD [0001] The present invention relates to improvements in climber's or tramper's packs, and to frames for such packs. BACKGROUND ART [0002] A modern pack consists of a sac in which equipment may be carried, the sac being mounted on a frame, and a shoulder harness secured to the sac or to the frame. Since carrying a heavy load supported only from the shoulders can lead to backache or even to back damage, a majority of modern packs also include a hip belt which is connected to the sac or the frame, generally at or close to the base of the sac, to transfer some of the load from the shoulders to the hips. [0003] Although using a hip belt reduces the strain on the back, the belt itself can cause problems to the wearer, due to the way in which the human body moves when walking. [0004] When a human being walks, he leans backwards and forwards with each step (FIG. 1) and from side to side with each double step (FIG. 2). As he leans to the supporting side when taking a step the...

AI Technical Summary

Benefits of technology

[0013] and wherein tensioning means are secured between each flexible rod at or adjacent the end of said flexible rod, and an adjacent portion of the hip belt; each said tensioning means being adapted to move the corresponding flexible rod so as to bow and tension said rod and provide a relatively rigid weight transmitting connection between said rod and the corresponding portion of the hip belt; the arrangement being such that said movement of said flexible rods tends to lift the frame and the pack, decreasing the loading on the shoulder harness and increasing the loading on the belt.

Problems solved by technology

Since carrying a heavy load supported only from the shoulders can lead to backache or even to back damage, a majority of modern packs also include a hip belt which is connected to the sac or the frame, generally at or close to the base of the sac, to transfer some of the load from the shoulders to the hips.

Although using a hip belt reduces the strain on the back, the belt itself can cause problems to the wearer, due to the way in which the human body moves when walking.

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.

However, the hip belt described in New Zealand patent No. 201751 was not a complete solution to the problem:—because the hip belt was secured to the pack by a comparatively narrow connection, the load transfer from the pack to the hip belt was concentrated at the connection point and was distributed around the pelvic girdle of the wearer only by the stiffness of the hip belt.

The more rigid the hip belt, the better the load transfer, but in general, the more rigid a hip belt is, the less comfortable it is to wear.

Thus, the problem remained of providing a harness which permitted relative movement between the wearer's back and hips in at least three directions but which provided an efficient load transfer around the pelvic girdle of the wearer without resorting to the use of an uncomfortably stiff hip belt.

New Zealand Patent 335931 provides a frame and hip belt which give excellent weight transfer, but both the frame and the hip belt are bulky and thus comparatively heavy to wear, and are relatively expensive to manufacture.

However, the degree of fixing of the resilient rods, and hence the amount of load transfer to the hip belt, depends upon the tightness of the hip belt:—there is no provision for altering the amount of load transfer independent of the tightness of the hip belt.

Further, increased flexing of the resilient rods tends to pull the pack load closer to the user's back, but does not necessarily lift part of the load from the shoulder harness.

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