Pack frame and suspension means

BACKGROUND OF THE INVENTION

Pack frames have become popular due to many advantages thereof with respect to a conventional ruck sack or flexible bags to which shoulder engaging straps are connected.

A common fault of the pack bag or ruck sack is that the load carried in such a sack tends to bulge the sack away from the human body, and to dispose the center of gravity of the load in the sack outward and rearwardly from the body in a cantilever fashion so as to create a substantial force moment as compared to a comparable load carried close to the body and properly held in place by a substantially rigid pack frame.

Pack frames also have the advantage that they are substantially rigid and may hold a vertically elongated load in neat, compact position with the center of gravity of the load close to the body.

Furthermore, pack frames have also had another advantage, that being the division of load between the shoulders and the hips of wearer. Prior art pack frames have utilized shoulder engaging straps and, also, hip surrounding straps which are generally connected to opposite vertical rail members of the pack frame so as to bring a cross strap between the vertical members of the frame, such that the cross strap bears on the upper rear portions of the hips.

This arrangement, however, creates a substantially rigid couple between the shoulders of the wearer and his hips, so that motions of the hips relative to the shoulders and twisting or bending of the wearer’s torso is resisted by the rigidity of the pack frame. Accordingly, each walking step or motion tends to cause the hip surrounding structure rigidly connected to the lower portion of the pack frame to create a tightening stress on a shoulder strap, such that the stress is transmitted to the shoulders of the wearer.

When carrying heavy loads on a pack frame in this manner, a substantial amount of working of the rigid frame between the hips and the shoulders transfer hip movement stresses to the shoulder straps, and consequently, tends to create undue fatigue of the wearer.

SUMMARY OF THE INVENTION

The present invention employs a substantially rigid pack frame provided with shoulder engaging straps and a hip engaging belt from which downwardly directed flexible suspension straps are extended and from which a lower portion of the pack frame is suspended in free swingable relation to the hip engaging belt of the invention.

The hip engaging belt of the invention is of novel construction, and generally when worn, conforms to the ₅ downwardly diverging geometry of a person’s hips, such that the belt is a generally hollow, frusto-conical structure.

The belt of the invention is composed of a resilient body structure preferably of lightweight foam material, 10 and of a flexibility capable of conforming to the hips in a comfortable manner, but which has sufficient rigidity to transfer loading uniformly around the wearer’s hips in accordance with the load of the pack frame suspended from said suspension straps.

The length of the suspension straps between the belt and their connection with the frame provides for a desired amount of free swingable movement of the frame relative to the hip engaging belt of the invention, and the relative resilience or hardness of the body structure of 20 the belt permits the belt to be comfortable, and yet capable of conforming with the body and distributing load quite evenly around the hips.

Accordingly, the invention provides for free hip movement relative to the frame while the hips are carrying a 25 substantial portion or share of the load on the frame, such that the shoulder straps of the invention which are connected to the frame only need to bear a share of the load supported on the frame.

Accordingly, it is an object of the present invention 30 to provide a novel pack frame suspension means, wherein a substantially rigid pack frame is provided with shoulder engaging straps and a hip engaging belt from which a lower portion of the frame is suspended in free swingable and movable relation to the belt so as to permit the hips 35 to share load on the frame relative to a share of load carried by the shoulder straps during which the hips may move freely relative to the frame without transferring undue stress loads from and to the shoulders of a person engaged by the shoulder straps of the invention.

Another object of the invention is to provide a novel hip engaging belt and pack frame suspension means.

Another object of the invention is to provide a pack frame suspension belt of novel construction, and having a novel resilient body ranging in resilience from 10 pounds to 24 pounds loading to compress a square inch pad to a depth of approximately one-fourth inch into the side of a foam layer approximately one-half inch thick, whereby the belt is capable of readily conforming 5q to the downwardly diverging portions of human hips, and yet has sufficient rigidity to transfer load evenly around the hips in accordance with load imposed to the belt by flexible suspension straps which support the lower end of a pack frame in free swingable movement relative 55 to the belt of the invention.

Another object of the invention is to provide a novel pack frame suspension means, wherein flexible straps are extended downwardly from the hip engaging belt and θθ support a lower portion of the pack frame in free swingable and movable relation to the belt; said suspension straps having a plurality of vertically spaced connection portions adapted to permit the frame to be suspended at various lengths of said suspension straps in order to vary g5 the degree of free swingable movement of the frame relative to the hip engaging belt of the invention.

Another object of the invention is to provide a pack frame suspension means which is very simple in construction, very strong, durable and lightweight in propor70 tion to its load carrying capabilities and relative to its comfort to the wearer, and which provides an optimum load carrying opportunity for the hips as well as the

3,516,586 ο

shoulders of a person wearing the pack frame suspension means of the invention.

Further objects and advantages of the present invention may be apparent from the following specification, appended claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear elevational view of a pack frame, and a pack frame suspension means in accordance with the present invention;

FIG. 2 is a side elevational view of the invention, as shown in FIG. 1, and taken from the line 2—2 thereof;

FIG. 3 is a plan sectional view taken from the line 3—3 of FIG. 1;

FIG. 4 is a fragmentary sectional view taken from the line 4—4 of FIG. 2;

FIG. 5 is a fragmentary side elevational view of the hip engaging belt of the invention, and suspension straps in connection therewith, and showing the belt laid out in flat straight condition;

FIG. 6 is an enlarged fragmentary sectional view taken from the line 6—6 of FIG. 1;

FIG. 7 is a fragmentary sectional view taken from the line 7—7 of FIG. 6; and

FIG. 8 is a view similar to FIG. 6, showing a modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1 of the drawings, the invention comprises a substantially rigid pack frame 10 which may be made of aluminum or magnesium tubing, for example. However, this pack frame 10 may be made of any suitable material, such as resin and fiber glass, the frame may be made in the form of a plate member rather than an open frame, if desired. However, the frame 10 is generally rigid in accordance with the general use of such pack frames.

The particular frame, as shown in FIG. 1 of the drawings, includes opposite side rails 12 and 14 interconnected by cross members 16, 18 and 20 which are preferably tubular members welded or otherwise secured to the side rails 12 and 14. These cross members 16, 18 and 20 are preferably curved in a rearward convex configuration, as shown best in FIG. 3 of the drawings.

Pivotally coupled to an upper portion of the frame 10 are shoulder engaging straps 22 and 24 which are adapted to engage shoulders 26 of a human body.

These straps 22 and 24 are generally pivotally connected to the cross members 16 by pins 28 and 30, respectively.

Lower ends of the shoulder straps 22 and 24 are connected to lower portions of the respective frame side rails 12 and 14 by means of pins 32 and 34, respectively.

Wrapped around the frame side members 12 and 14 in the conventional manner is a back bearing strap 36 adapted to bear against the back of the wearer, as shown best in FIG. 2 of the drawings.

The invention comprises a novel frame suspending hip engaging belt 38. This belt 38 is adapted to surround the hips of a human body substantially at 40, and this belt 38 is provided with opposite end portions 42 and 44, as shown in FIGS. 2, 3 and 5 of the drawings. A buckle 46 connected to the end 42 is adapted to receive the end 44 and to hold opposite ends of the belt together and in juxtaposition with relation to the front of the wearer’s body substantially at 40, as shown in FIG. 2 of the drawings, in order to maintain the hip engaging belt of the invention in a fitted relation to the hips of the wearer.

The hip engaging belt of the invention, as shown in FIGS. 3 and 4 of the drawings, is a hollow substantially frusto-conical structure, the belt being flexible and generally comfortable to the downwardly diverging shape of the wearer’s hips.

As shown in FIG. 4 of the drawings, reference charac4 ters A and B generally indicate the conical angles of the downwardly diverging frusto-conical structure of the belt as it conforms to the downwardly diverging geometry of a wearer’s hips. These angles may vary according to the geometry of the wearer’s hips and the flexibility of the belt 38, as will be hereinafter described, conforms so that as these angles vary with respect to various wearers, the belt fully conforms to the angularity of the wearer’s downwardly diverging hips, and yet fully distributes the load around the wearer’s hips.

Connected to rearward portions of the belt 38 generally at a connection portion seam 48 are suspension strap means 50 which comprise a pair of flexible suspension straps 52 and 54 which extend downwardly from the connection portion seam 48, and as shown in FIG. 5 by broken lines, the suspension straps 52 and 54 may swing freely back and forth in a lateral direction, as shown in FIG. 5, and forwardly and rearwardly as indicated by arrows C and D in FIG. 6 of the drawings.

These suspension straps 52 and 54 are each provided with a plurality of metal eyelets 56 through which connection pins extend. These eyelets 56 are generally designated as second connection portions of the straps 52 and 54. These second connection portions being pivotal connections for the straps and lower portions of the frame side rails 12 and 14, respectively.

Pins 58 and 60 extend through the side rails 12 and 14 and through the eyelets 56 which form the second connection portions for the straps 52 and 54. A detailed disclosure of the pin 60 extending through the frame side rail 14 may be found in FIG. 6 which also shows in detail the extension of said pin 60 through one of the eyelets 56. The pin 60 is provided with an enlarged head 62 abutting one side of the respective eyelet 56.

As shown in FIG. 6, the suspension strap connection portion or seam 48 in the belt 38 secures the flexible straps 52 and 54 to the belt, and the distance between the connection seam or connection portion 48 and the respective eyelet 56 or second connection portion may vary in length from 2 to 6 inches, as desired. In some cases, this length may vary considerably more depending upon the proportions desired.

It will be seen that these suspension straps 52 and 54 are flexible laterally and forwardly and rearwardly so as to suspend a lower portion of the frame 10 in a free swingable movement in all directions relative to the belt 38 which transmits load from the frame to the hips of the wearer, as shown in FIG. 2 of the drawings.

As indicated by a dimension E in FIG. 6 of the drawings, the conical interference of the belt 38 in a vertical direction of the downwardly diverging portions of the wearer’s hips may equal substantially one and one-half inches and the length of the belt at this interference area may be substantially 30 inches. Accordingly, it will be seen that the vertical load bearing surface on the hips may equal substantially 45 square inches.

As shown, that each square inch of the wearer’s hips may bear .5 p.s.i. The loading on the hips, for example, might be 22½ pounds, while a comparable load might be borne by the shoulder straps 22 and 24. Thus, a total loading on the frame equalling 50 pounds would be equally divided between the shoulder straps and the hip engaging belt 38. Greater or lesser loading on the frame may be shared equally or differently by the belt and the shoulder straps, as desired. For example, when opposite ends 42 and 44 of the belt are tightened with the buckle 46, the belt 38 tends to ride upwardly on the downwardly diverging portions of the wearer’s hips and tends to assume more load. Thus, a greater loading or greater share of loading may be borne on the hips than on the shoulders, if desired, or a lesser share may be borne on the hips and a greater share of the load may be borne by the shoulders, as desired. If a person wishes to bear most of the load by the shoulder straps, the buckle 46 may be loosened allowing the belt 38 to move downwardly a slight distance to

3,516, thereby place more load on the shoulder straps 22 and 24.

Accordingly, it will be appreciated that the relative loading on the shoulders and the hips may be controlled entirely by adjustment of the opposite ends 42 and 44 of the belt relative to the buckle 46 which will hold the g belt in certain frusto-conical juxtaposition relative to the hips.

As a person changes his clothing, the belt may thus be adjusted to compensate for the varied changes in dimension of the person’s body by reason of the addition ₁₀or subtraction of clothing.

The hip engaging belt itself is of novel construction comprising a resilient body structure which is preferably made of lightweight resilient foam. This body structure being designated 64 and being encapsulated by a 15 suitable fabric sheath which may be made of nylon or other suitable material. This sheath being designated 66.

The stitch structure forming the seam 48 is designated 68 and extends completely through the body 64 and through opposite sides of the sheath 66 from the front 20 portion 70 of the belt to the rear portion 72 thereof, as 'shown in FIG. 6 of the drawings.

When the seam 48 is made by a sewing machine, the sheath 66 is placed in tension around the foam body 64 due to relative compression of the foam body at 25 the seam 48, thus the sheath and body are in respective tension and compression relative to each other.

In accordance with the disclosure of FIGS. 1 to 7, it will be appreciated that the compressibility or relative resilience or hardness of the body structure 64 is critical ³⁰to a proper operation of the belt in its ability to conform with the wearer’s hips in a comfortable manner, and to at the same time, evenly distribute loading around the wearer’s hips from the suspension straps 52 and 54 which carry loading at the lower portion of the frame 10. Ac- ³⁵cordingly, the foam body 64 ranges in resilience, such that as little as 10' pounds or as much as 24 pounds loading may be required to compress a one square inch pad to a depth of approximately one-fourth inch into the side of a foam layer approximately one-half inch ⁴⁰thick.

It will be appreciated that if the foam body 64 is much harder or less flexible than that prescribed in the foregoing range, it will be uncomfortable to the wearer and will not properly conform with the downwardly diverging con- ⁴⁵figuration of a wearer’s hips as the wear flexes his muscles and momentarily makes slight changes in this downwardly diverging configuration. Accordingly, a very stiff belt will not properly conform during movements of the body and will be uncomfortable. Furthermore, a rela- ⁵⁰tively rigid belt will not distribute the load evenly due to the lack of conformance and will create uncomfortable conditions of the wearer’s hips.

Should the belt be made of structure much softer or less capable of bearing load than that described in the foregoing range, the sheath 66 will be pulled out of shape by the suspension straps 52 and 54 in such a manner that it will tend to pull into a rope-shape and will not distribute load around the wearer’s hips. Accordingly, it will be appreciated by those skilled in the art that the ⁶⁰relative compressibility and/or resilience of the foam body 64 is a very important factor of the present invention.

The belt 38 from its upper edge 76 to its lower edge 78 may be approximately 4 to 6 inches in the vertical ^b5direction, however, slightly over 4½ inches is a preferred dimension for the width of the belt 38.

Inasmuch as the belt 38 is resilient and conforming to the downwardly diverging portions of a human’s hips, the angles A and B, as shown in FIG. 4, may vary slightly as the belt conforms with the flexing muscles of the person’s hips during a walking movement, and the corresponding angles designated F in FIG. 6, may vary slightly from side to side the the wearer’s hip muscles flex and 75

586 during this time, the flexible belt structure of the invention alternately conforms from side to side and the free swinging movement of the lower portion of the frame is permitted from side to side as hereinbefore described, and fore and aft depending upon the various movements of the body from side to side movement or to the forward and rearward tilting movement of the torso above the waist.

In the modification, as shown in FIG. 8 of the drawings, the belt 38 is formed of two layers of material, one layer being designated 80, and the other layer 82. The layer 80 is a stiff load distributing layer which may be of heavy fabric, leather or plastic to which the suspension straps 52 and 54 are secured. The layer 82 of the belt 38 is preferably of very soft foam or other suitable padding material adapted to conform to the downwardly diverging portions of the wearer’s hips, the material of the layer 82 being sufficiently soft to provide comfort and to conform to the wearer under loading of the relatively rigid belt layer 80.

The layers 80 and 82 may be mounted or molded together or stitched together, if desired.

The layer 82 may be of material softer than the hereinbefore described range of resilience, if desired.

It will be appreciated that the material of the layer 82 may be softer than the material of the layer 64, if desired, due to the fact that the relatively rigid layer 82 carries the suspension straps 52 and 54 and tends to operate as a load distributor relative to the soft layer 82.

This soft layer 82 may be an exo-thermally molded belt layer exo-thermally molded and mounted to the layer 80, and the layer 82 may have a smooth abrasion resistance skin, such as conventionally produced on the external surfaces of polyurethane foam, or the like.

It will be obvious to those skilled in the art that various modifications of the invention may be resorted to without departing from the spirit of the invention.