Backpack frame system

Abstract

A backpack frame system includes a first layer of thermally bondable material including at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions. The backpack frame system also include a second layer of thermally bondable material including at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, at least two intermediate horizonal portions connecting the at least two column portions between the top horizontal portion and the bottom horizonal portion, and at least one top flap, where the second layer is welded to the first layer. Pockets with rods are positioned in between the at least two column portions of the first layer and the at least two column portions of the second layer.

Description

[0001] Attorney Docket No 55656-10370

[0002] BACKPACK FRAME SYSTEM

[0003] TECHNICAL FIELD

[0004] The present disclosure relates generally to backpacks, and in particular framed backpacks.

[0005] BACKGROUND ART

[0006] Backpacks have been used for many years to carry a given load of contents on the back of a user. Modem backpack designs configured to carry moderate to large loads (in terms of weight and / or bulk) usually fall into one of two categories: external frame backpacks and internal frame backpacks. Both internal and external frame backpacks have a waist or hip belt and a yoke. The hip belt is designed to transfer a substantial amount of the weight of the backpack and contents from rigid or semi-rigid supports of the backpack to the hips of the backpack user. The yoke is primarily designed to stabilize the backpack load and more properly position portions of the backpack relative to the user's torso and shoulders. However, the yoke may also transfer a small amount of the weight of the backpack and contents to the user's shoulders, and in certain situations, may alternatively be called on to support the full weight of the backpack and contents without the use of the hip belt.

[0007] External frame backpacks ty pically include rigid, tubular frames (e.g., formed of aluminum or other metals or rigid materials) for supporting the weight of a pack bag. Such external frame backpacks can be particularly useful in securely holding bulky or heavy contents. The frame members of these frames are usually rigidly interconnected by a welded or pinned connection. A load is typically carried inside the pack bag or can be connected directly to the external frame. Pack bags and the like may be connected with the frame by, for instance, stitching a sleeve, loop or pocket formed on the pack bag over the frame members.

[0008] One drawback of the rigid frame design is that forces generated by an impact incident on the attached pack bag or the frame itself create stresses that tend to remain concentrated at either (1) the region of impact, (2) in the pack bag itself, or (3) at the associated connection points of the pack bag with the frame. For example, because of the rigid nature and lack of give of the typical external frame under force loading, loads on the pack bag must often generate a high level of tension on the pack bag material before appreciable transferring of the loads to the frame occurs. When an impact is severe, the locations of stress concentration tend to tear or fracture, and because pack bag material is not as strong as the rigid frame material, the bag may rip open and scatter the contents that were held therein. Attorney Docket No 55656-10370

[0009] Some external frame backpacks allow users to attach extra pack bags to the frame as needed. However, these extra bags are often connected via pins or strapping wrapped around the tubular frame members. Such connections are prone to fractures and tearing when the frame is under stress. Another disadvantage of external frame backpacks is the tendency for such packs to be unstable relative to internal frame packs because the load is usually placed laterally farther away from the user's center of gravity7, a situation which is exacerbated by the rigidness of the external frame.

[0010] Internal frame backpacks generally allow a carried load to better conform to the profile of a user's back so that stresses on the user's body are reduced as compared to load carrying with an external frame backpack. However, the frame components of typical internal frame packs tend to become distorted from their original shape under the weight and shape of the backpack's load. Another disadvantage of internal frame backpacks is that the shape of the pack bag is dictated largely by the shape of the frame. Accordingly, the load side of the backpack often tends to mirror the wearer's back shape which may not be optimum for organizing a load thereon. As a result, internal frame backpacks do not effectively store contents that could otherwise be retained in the backpack. The relationship between the bag and the support members also prevents internal pack bags from being removable and modular. As such, the user is unable to swap a larger pack bag for a smaller pack bag without changing backpacks entirely.

[0011] Therefore, many current external and internal frame designs lack the ability to form a backpack with modular pack bags or load carriers while also providing a frame structure that conforms well to a user's body profile, efficiently transfers loads to the user's body frame, and is resistant to impact loads incident either directly on the frame or indirectly through components attached to the frame.

[0012] DISCLOSURE OF INVENTION

[0013] This Disclosure introduces a selection of concepts relating to this technology7in a simplified form as a prelude to the Best Mode For Carrying Out The Invention that follows. This Disclosure is not intended to identify key or essential features.

[0014] In some embodiments, a backpack frame system includes a first layer of thermally bondable material including at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions; a second layer of thermally bondable material including at least two column portions, a Attorney Docket No 55656-10370 top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, at least two intermediate horizontal portions connecting the at least two column portions between the top horizontal portion and the bottom horizontal portion, and at least one top flap, wherein the second layer is thermally bonded to the first layer; pockets positioned in between the at least two column portions of the first layer and the at least two column portions of the second layer, and rods positioned in the pockets, wherein the rods are retained in the pockets by the at least one top flap extending over the first layer.

[0015] In some embodiments, a method of manufacturing a backpack frame system includes cutting a first layer of thermally bondable material, where the cut first layer includes at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions; cutting a second layer of thermally bondable material, where the cut second layer includes at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, and at least two intermediate horizontal portions connecting the at least two column portions between the top horizontal portion and the bottom horizontal portion; thermally bonding the first layer and the second layer together to form at least two pockets in the at least two column portions; attaching at least two horizontal stays to the at least two intermediate horizontal portions of the second layer; inserting a rod into each of the at least two pockets; and folding at least one flap of the second layer over the first layer to close the at least two pockets.

[0016] In some embodiments, a backpack frame system includes a first layer of polyurethane- coated fabric including at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions; a second layer of polyurethane-coated fabric including at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, at least two intermediate horizontal portions connecting the at least two column portions between the top horizontal portion and the bottom horizontal portion, wherein the second layer is joined with the first layer; pockets positioned in between the at least two column portions of the first layer and the at least two column portions of the second layer; and rods formed of pultruded polyurethane-infused glass fiber positioned in the pockets. Attorney Docket No 55656-10370

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The foregoing Disclosure, as well as the following Best Mode For Carrying Out The Invention, will be better understood when considered in conjunction with the accompanying drawings in which like reference numerals refer to the same or similar elements in all of the various views in which that reference number appears.

[0019] FIG. 1 is a perspective view of a prior art backpack frame system in accordance with one embodiment of the present invention.

[0020] FIG. 2 is a partial front elevational view taken generally at the location designated by the indicator 2 in FIG. 1 showing a portion of the prior art latticework of horizontal and vertical support members attached to the membrane webbing and with portions of the sleeves cut away to reveal the support members.

[0021] FIG. 3A is a front elevation view showing a backpack frame system in accordance with some embodiments of the present invention.

[0022] FIG. 3B is a rear elevation view showing the backpack frame system of FIG. 3A.

[0023] FIG. 4A is a front elevation view depicting a first stage in a method for forming a backpack frame system in accordance with some embodiments of the present invention.

[0024] FIG. 4B is a front elevation view depicting a second stage in a method for forming a backpack frame system in accordance with some embodiments of the present invention.

[0025] FIG. 4C is a rear elevation view depicting a third stage in a method for forming a backpack frame system in accordance with some embodiments of the present invention.

[0026] FIG. 4D is a front elevation view depicting a fourth stage in a method for forming a backpack frame system in accordance with some embodiments of the present invention.

[0027] FIG. 4E is a front elevation view depicting a fifth stage in a method for forming a backpack frame system in accordance with some embodiments of the present invention.

[0028] FIG. 5 is a flow diagram for a method of forming a backpack frame system in accordance with some embodiments of the present invention.

[0029] FIG. 6 is a perspective view of the backpack frame system of FIG. 3 A.

[0030] FIG. 7 is a front view of a rod subassembly for a backpack frame system in accordance with some embodiments of the present invention. Attorney Docket No 55656-10370

[0031] FIG. 8 is a cross-sectional view of the rod subassembly of FIG. 7 taken along line 8-8.

[0032] FIG. 9 is a front schematic of a yoke for a backpack frame system in accordance with some embodiments of the present invention.

[0033] FIG. 10 is a front schematic of a yoke for a backpack frame system in accordance with some embodiments of the present invention.

[0034] FIG. 11 is a front schematic of a yoke for a backpack frame system in accordance with some embodiments of the present invention.

[0035] Further, it is to be understood that the drawings may represent the scale of different components of various examples: however, the disclosed examples are not limited to that particular scale. Further, the drawings should not be interpreted as requiring a certain scale unless otherwise stated.

[0036] BEST MODE FOR CARRYING OUT THE INVENTION

[0037] A backpack frame system addressing the limitations of traditional framed backpacks is described in U.S. Pat. No. 7,673,777 (the ‘777 Patent), which is herein incorporated by reference in its entirety. Such a backpack frame system includes a latticework of vertical and horizontal semi-rigid support members, each member contained within and captured between opposite ends of a sleeve which is mounted to a membrane. An adjustable yoke is coupled with the membrane and a hip belt attached to the sleeves of the vertical support members and / or the membrane to enable loads carried by the support members to be transferred to the user's body. The sleeves of the horizontal or cross support members are attached with the sleeves of the vertical or upright support members through a flexible connection between abutting portions. This connection allowed for increased flexure without permanent deformation or yield of the frame system to properly conform to a user's body profile under loading and absorb impact loads incident upon the support members. Modular pack systems may be attached to the backpack frame system.

[0038] Referring initially to FIG. 1, a prior art backpack frame system (“frame system”) is designated by the reference numeral 10. The frame system 10 includes a base frame assembly 11 coupled with a hip belt 320 and a shoulder strap assembly 201 with shoulder straps 220 and yoke 200 to form a backpack that is configured to be worn by a user to transport various contents.

[0039] With additional reference to FIG. 2 the base frame 11 includes a latticework of horizontally and vertically oriented semi-rigid support members or frame stays 22, 23, 24, 26, 27, and 28 that are encased in sleeves 12, 13, 14, 16, 17, and 18, respectively, and held in place by a membrane Attorney Docket No 55656-10370

[0040] 30 forming various generally rectangular arrays of stays. Each of the frame sleeves 12, 13, 14, 16, 17, and 18 are attached with at least one of the other frame sleeves 12, 13, 14, 16, 17, and 18 and / or with the membrane 30 to form the structure of the base frame 11.

[0041] The base frame 11 includes a left vertical frame stay 22, housed within a sleeve 12, a center vertical frame stay 23, housed within a sleeve 13, and a right vertical frame stay 24. housed within a sleeve 14. The vertical frame stays 22, 23 and 24 are positioned by the sleeves 12, 13 and 14 (or “vertical stay sleeves” 12, 13 and 14) to be generally parallel with one another and achieve the vertical orientation when the frame system 10 is in the upright position shown in FIG. 1. The stays 22, 24 are outermost stays. Center vertical stay 23 is positioned generally along a vertical centerline of the membrane 30 between and equidistant from sleeves 12 and 14. Base frame 11 further includes an upper cross or horizontal frame stay 26, housed within a sleeve 16, an intermediate cross or horizontal frame stay 27, housed within a sleeve 17, and a lower cross or horizontal frame stay 28. housed within a sleeve 18. The horizontal frame stays 26, 27, and 28 are positioned by the sleeves 16, 17 and 18 (or “horizontal frame sleeves” 16, 17 and 18) to be spaced from and generally parallel with one another, extending laterally between left and right outermost vertical frame stays 22 and 24 and over the center vertical frame stay 23 to achieve the horizontal orientation when the frame system 10 is in the upright position. As shown in FIG. 1, sleeve 16 associated with upper horizontal frame stay 26 extends laterally between the vertical stay sleeves 12. 14 to opposing points on the sleeves 12, 14 proximal to and slightly below the upper ends of sleeves 12, 14, sleeve 17 associated with middle horizontal frame stay 27 extends between approximately the vertical midpoints of vertical stay sleeves 12, 14, and sleeve 18 associated with lower horizontal frame stay 28 extends laterally between the vertical stay sleeves 12, 14 to opposing points on the sleeves

[0042] 12, 14 located several inches above the lower ends of sleeves 12 and 14.

[0043] The frame stays 22, 23. 24. 26. 27, and 28 are constructed of Ys-inch wide by ‘ / s-inch thick carbon fiber reinforced fiberglass and are semi-rigid and elastically deformable. Frame sleeves 12,

[0044] 13, 14, 16, 17, and 18 are constructed of a durable material, such as nylon strapping or polyester strapping similar to the material frequently used in automobile seatbelts. Membrane 30 is flexible and formed with 1000 denier Cordura® nylon.

[0045] Each of the vertical stay sleeves 12, 13, and 14 is held in position by membrane 30. Membrane 30 takes on a generally rectangular shape to provide a mounting surface for the vertical stay sleeves 12, 13 and 14. Membrane 30 extends laterally across the vertical stay sleeves 12, 13 and 14, and extends vertically across the horizontal stay sleeves 16, 17 and 18 with upper and Attorney Docket No 55656-10370 lower portions of the membrane 30 extending above the uppermost horizontal sleeve 16 and below the lowermost horizontal sleeve 18. Vertical stay sleeves 12, 13, and 14 are sewn down or otherwise attached generally along their peripheral edges. Horizontal stay sleeves 16, 17 and 18 are directly attached on opposed lateral ends thereof with the left and right vertical stay sleeves 12, 14.

[0046] Vertically oriented straps 42 and 46, FIG. 1, are attached to the base frame 11 near the lower edge of the membrane 30 and proximal to lower ends of vertical stay sleeves 12 and 14. Straps 42 and 46 are threaded through buckles 44 and 48, which may be adjusted to various positions along straps 42 and 46. Buckles 44 and 48 can be coupled together with either buckles 64 and 68, or buckles 74 and 78, to secure objects between straps 42 and 46 and base frame 11. Straps 42 and 46 are long enough so that when coupled with buckles 64 and 68, or buckles 74 and 78, straps 42 and 46 extend across a variety7of objects. Buckles 44, 48, 64, 68, 74 and 78 are formed using releasable male and female buckle connectors.

[0047] A first set of horizontally oriented straps 86 and 96, FIG. 1, are positioned along the right side of base frame 11 and are attached to vertical stay sleeve 14. A second set of horizontally oriented straps 82 and 92 are positioned along the left side of base frame 11 and are attached to vertical stay sleeve 12. Straps 82 and 86 are attached with the respective outermost vertical stay sleeves 12 and 14 generally at the same height as one other and approximately midway between horizontal stay sleeves 16 and 17. Likewise, straps 92 and 96 are similarly attached with the respective vertical stay sleeves 12 and 14 at the same height with respect to each other and approximately midway7between horizontal stay sleeves 17 and 18.

[0048] Straps 82 and 86 are threaded through buckles 84 and 88, which may be adjusted to various positions along straps 82 and 86. Buckles 84 and 88 can be coupled together and are formed using releasable male and female buckle connectors. Similarly buckles 94 and 98 can be coupled together and are formed using releasable male and female buckle connectors. Coupling together of buckles 84 and 94 with corresponding buckles 88 and 98 secures objects between straps 82, 86, 92 and 96 and base frame 1 1. Straps 82, 86, 92 and 96 are long enough so that when coupled with 94, 88, 84 and 98, straps 82, 86, 92 and 96 extend across a variety7of objects.

[0049] Horizontal straps 82, 86, 92 and 96 and vertical straps 42, 4652, 56, 62, 66, 72 and 76 are formed from durable fabric-like material (e.g., similar to the frame sleeves 12, 13, 14, 16, 17, and 18), and are anchored with the base frame 11 by sewing the straps to the respective base frame component (i.e., membrane and / or frame sleeves) or by other means. Horizontal straps 82, 86, 92 Attorney Docket No 55656-10370 and 96 and corresponding buckles 84, 88, 94 and 98, as well as vertical straps 42, 46, 52, 56, 62, 66, 72 and 76 and corresponding buckles 44, 48, 54, 58, 64, 68, 74 and 78 can be used for attaching a load to frame system 10. Additionally, the aforementioned buckles and straps can be used for compressing loads (i.e., objects) attached to the frame system 10. When used for load compression, the base frame 11, substantially through stays 22, 23, 24, 26, 27 and 28, transfers tension more uniformly throughout frame system 10 than either traditional external frame or internal frame backpacks. More specifically, straps 42, 46, 52, 56, 62, 66, 72, 76, 82, 86, 92 and 96 transfer this tension more directly to the horizontal and vertical frame stays 22, 23, 24, 26, 27, and 28, which are designed to flex slightly under load to increase tension distribution throughout base frame 11. Membrane 30 also reduces the occurrence of stress concentrations in the frame system 10 under load by distributing the tension from the straps across a broad area of material to all of the frame stays 22, 23, 24, 26, 27, and 28 within the frame sleeves 12, 13, 14, 16, 17. and 18. The attachment of horizontal straps 82, 86, 92 and 96 are vertical straps 42, 46, 52, 56, 62, 66, 72 and 76 with the base frame 11 is achieved by durable fabric-like material.

[0050] Flexible seam 34 is formed broadly by sewing down the material of horizontal stay sleeves 16, 17, and 18 to the material of the left and right vertical stay sleeves 12, 14.

[0051] While the prior art backpack frame system described above has advantages over other framed backpack system, the inventors have appreciated certain limitations with its construction. First, the backpack frame system is comprised of numerous components, which are assembled individually by hand. Such a construction is therefore difficult and time-consuming to produce, and requires significant skill in sewing and soft goods construction. The inventors have appreciated an improved construction that has fewer components, is simpler to manufacture, more repeatable to manufacture, and retains or improves the performance of the construction described above. Secondly, the inventors have appreciated that certain combinations of materials of a backpack frame system may provide enhanced performance, including weight reduction, improved load transfer, hydrophobicity, and improved durability while maintaining other performance characteristics.

[0052] According to some embodiments, a backpack frame system is formed primarily of two layers of weldable or thermally bondable material, such as polymer-coated fabric. The two layers of material may be cut in a single operation, such as by die cutting or by laser cutting. The two layers of material may be layered on top of one another, and welded (e g. dielectrically welded) in a single operation to form the overall structure of the backpack frame system, including at least Attorney Docket No 55656-10370 two vertical pockets (e.g., four vertical pockets) in corresponding vertical columns, and horizontal portions interconnecting the vertical columns. The pockets may be formed by the welding or thermal bonding process, with no further stitching or fastening required. Vertical stay rods may be inserted into the pockets, and may be enclosed by folding a flap or flaps of the second layer over the first layer, thereby closing the vertical pockets. The flap or flaps may be secured by small stitches, adhesives, or a second welding or another thermal bonding operation. In some cases, an automated sewing machine may be employed, as the location of the stitches is repeatable due to the cut weldable or thermally bondable material layers. Horizontal stays may be attached to the structure formed by the two welded or thermally bonded layers with a third thermal bonding operation or additional stitching. In this manner, a backpack frame system including a lattice of horizontal and vertical stays may be formed quickly and reliably, without skilled technique in sewing or soft goods construction. The use of weldable or thermally bondable materials further improves rigidity of the frame for load transfer compared to the sewn frame described above. Additionally, such a backpack frame system does not absorb water due to the use of weldable or thermally bondable materials, which are hydrophobic.

[0053] In some embodiments, a backpack frame system may include vertical stay rods formed of pultruded polyurethane-infused glass fiber stays. The inventors have appreciated that such stays including a resin content of approximately 20% to 80% fiber provides a stiff stay rod that retains durability under extreme bending and shock loads (e.g., during a drop). The use of pultruded polyurethane-infused glass fiber contrasts against prior rods which may be formed of carbon fiber (e.g., carbon fiber viny tester resin). Traditional fiberglass rods may be overly flexible, and carbon rods may be brittle and susceptible to fractures. The pultruded polyurethane-infused glass fiber rods therefore may have a higher impact resistance than carbon fiber rods, and may exhibit less breakage when subjected to impacts or shock loading. The pultruded polyurethane-infused glass fiber may provide a significant increase in flexion prior to failure or breakage, while maintaining a low weight. Polyurethane glass-fiber may have additional benefits when used in adverse weather conditions, including wet and freezing conditions. Compared to carbon rods, the polyurethane glass-fiber may retain less water, and may be less brittle at temperature near or below freezing (32° F). Additionally, the inventors have also appreciated the benefits of cylindrical rods that provide a consistent bending profile in all directions, compared with carbon fiber rods that are flat.

[0054] In some embodiments, a backpack frame system may include vertical stay rod subassemblies including rounded caps positioned on the ends of a stay rod. Such caps may cover Attorney Docket No 55656-10370 an edge of the end of the stay rod, which may be abrasive within a vertical pocket. The rounded caps may reduce the amount of wear between the vertical stay rods and the pockets of a backpack frame system, thereby improving the durability and longevity’ of the backpack frame system. Furthermore, the caps may provide a space between the vertical rods and the pocket, thereby reducing friction and allowing the rods to rotate more freely within the pockets, thereby providing enhanced frame flexibility. In some embodiments, the rounded caps may be formed of a plastic material. In some cases, the rounded caps may be formed of a low-friction plastic material such as nylon (e.g., PA66). In other embodiments, other materials may be used, as the present disclosure is not so limited.

[0055] In some embodiments, a backpack frame system may include a frame and an adjustable yoke. The inventors have appreciated that specific dimensions and geometry of the frame and the adjustable yoke may enable a backpack frame system to more ergonomically fit a wide range of body types and sizes compared to prior backpack frame systems like that described in the ‘777 Patent. Specifically, the inventors have appreciated a frame that may be a single size and connected to one or more adjustable yokes providing a range of adjustability to the backpack frame system beyond conventional strap size adjustment. Additionally, the inventors have appreciated the benefits of an adjustable yoke having a shoulder strap angle that better accommodates plate carriers and other worn accessories in a military or law enforcement context. Backpack frame systems according to some embodiments herein may have shoulder strap yokes that are configured not to slide off of the top of plate carriers when worn over a plate carrier. Backpack frame systems according to some embodiments herein may provide an appropriate fit for men and women in the 2ndto 98thpercentile in size. In some embodiments, to accomplish this, a backpack frame system may include a yoke having an interior angle of between 60° and 70°, with a length of vertical adjustment relative to a frame of 14 inches and 24 inches. In some embodiments, a backpack frame system may include a waist strap having a circumference adjustment between 25 inches and 42 inches. In some embodiments, a backpack frame system may include a single frame and multiple yokes having an interior angle, length of vertical adjustment, and waist strap circumference adjustment in a subset of the ranges noted above. For example, in some embodiments, a single frame may be paired with three differently sized yokes: small, medium, and large, having: an interior yoke angle of 60, 65, and 70; a vertical adjustment relative to the frame of 14-18 inches, 16-20 inches, and 19-24 inches measured from a bottom of the frame; and a waist circumference adjustment of 25-32 inches, 28-37 inches, and 31-42 inches, respectively. Attorney Docket No 55656-10370

[0056] FIG. 3 A is a front elevation view and FIG. 3B is a rear elevation view showing a backpack frame system 300 in accordance with some embodiments of the present invention. The description of pack frame system 300 will use terms such as vertical and horizontal. These terms are used to describe the parts when the pack frame system 300 is in its normal upright orientation. Additionally, pattern shading is used in the below figures to illustrate different components for clarity', and no particular meaning is ascribed to the patterns unless expressly noted. As show n in FIG. 3A, the backpack frame system includes a first layer of thermally bondable (e.g., weldable) material 310 and a second layer of thermally bondable (e.g., weldable) material 320. The thermally bondable material may be a polyurethane-coated fabric, though other implementations are contemplated. The first layer 310 and the second layer 320 may be formed of the same material. The first layer 310 and the second layer 320 may be joined together (e.g., thermally bonded) to form an integral structure, as discussed further with reference to FIG. 4A. Together the first layer 310 and the second layer 320 form a lattice structure that forms the basis of the backpack frame system. The first layer and the second layer may be die cut or laser cut, such that their patterns match and are reliable repeatable during production.

[0057] According to some embodiments herein, layers of fabric material may be weldable to one another to form a backpack frame system. Weldable or thermally bondable fabric materials may include materials that are able to be bonded to one another to form an integrated structure via the application of energy to the fabric materials. For example, a weld or thermal bond between weldable material layers may be created by the application of external heat (e.g., via a heat press, heat gun, etc.) that melts portions of the material layers together. As an alternative example, a weld or thermal bond between weldable material layers may be created by the generation of heat within the weldable materials themselves (e.g., by RF welding, dielectric welding, ultrasonic welding, etc.). Weldable or thermally bondable materials may include polymer impregnated laminate textiles. The inventors have appreciated the specific benefits in a backpack frame system of a weldable or thermally bondable material having a weight of between 15 and 23 oz. / yd2, between 17 and 21 oz. / yd2, and preferably between 17.5 oz / yd2and 20.5 oz / yd2. The inventors have further appreciated the benefits of a backpack fame system composed of a thermally bondable material layers that have a tongue tear minimum of 45 Ibf. In some other embodiments, other material parameters may be employed than those listed above, as the present disclosure is not so limited.

[0058] The first layer 310 includes four column portions 312A, 312B, 312C, 312D in the example of FIG. 3 A, though in other embodiments more or fewer column portions may be employed, for Attorney Docket No 55656-10370 example, at least two column portions. The first layer further includes a top horizontal portion 314 and a bottom horizontal portion 316 that interconnect the four columns 312A, 312B, 312C, 312D. The first layer may include no other horizontal interconnecting portions to retain torsional flexibility’ of the frame.

[0059] The second layer 320 is shown behind the first layer 310 in FIG. 3A. The second layer includes a commensurate number of columns as in the first layer 310, specifically four column portions 329 A, 329B, 329C, 329D as shown in the example of FIG. 3B. The column portions of the second layer are aligned with the column portions of the first layer 310. The second layer further includes a top horizontal portion 322 and a bottom horizontal portion 324, which interconnect the four columns 329A, 329B, 329C, 329D of the second layer and are generally aligned with the top and bottom portions of the first layer 310. The second layer 320 further includes a plurality of intermediate horizontal portions 326 positioned between the top portion 322 and the bottom portion 324. In the current example, as best shown in FIG. 3B, the second layer includes seven horizontal interconnecting portions: two between the first column 329A and the second column 329B, three betw een the second column 329B and the third column 329C, and two between the third column 329C and the fourth column 329D. The inventor has appreciated the benefits of this particular structure in providing appropriate support for the backpack frame system while allowing torsional flexion. The interconnecting horizontal portions may be configured to support horizontal stays (e.g., 340A, 340B) that provide horizontal support for the vertical columns. The second layer 320 may optionally include a center support portion 328, which may be used to support a harnessing adjustment system or a modular pack in the center of the frame.

[0060] The backpack frame system includes three horizontal stays 340A, 340B, 340C as shown in FIG. 3B. The horizontal stays may be attached to the second layer 320 via a welding process, adhesives or stitching. The horizontal stays may be aligned with the various interconnecting portions of the second layer 320, for example, the top portion 322 and intermediate portions 326 A, 326B. Such alignment may enable rapid production of the pack, as the location of the horizontal stays is easy to determine based on the pattern of the second layer 320. In some embodiments, the horizontal stays may include a fabric pocket housing a rod. The pocket may be formed by stitching, by welding, or by another thermal bonding process. In the case of welding or thermally bonding, the horizontal stays may also include tw o layers of weldable or thermally bondable material. The rod may be formed of pultruded polyurethane-infused glass fiber. Such an arrangement may have Attorney Docket No 55656-10370 beneficial effects compared to a rod formed of traditional fiberglass or carbon fiber, as discussed above and below with reference to FIG. 6. In some embodiments, the rod may be cylindrical.

[0061] As shown in phantom in FIGs. 3A-3B, the backpack frame system includes four pockets 330A, 330B, 330C, 330D aligned with each of the column portions 312A-D of the first layer 310 and the column portions 329 A-D of the second layer 320. The pockets 330A-330D are formed between the joined first layer 310 and second layer 320 by welded material of those two layers. That is, other than the pockets, every other overlapping portion of the first layer 310 and the second layer 320 are welded together to form an integral structure. Such a process is described with reference to FIG. 4A. The pockets 330A-330D are accessible at the top of the backpack frame system, though accessibility at the bottom is also contemplated. Vertical stay rods 332A, 332B, 332C, 332D are positioned in corresponding pockets, such that the backpack frame system includes four vertical rods. The rods may be formed of pultruded polyurethane-infused glass fiber. Such an arrangement may have beneficial effects compared to a rod formed of traditional fiberglass or carbon fiber, as discussed above and further below in reference to FIG. 6. In some embodiments, the rods may be cylindrical. The rods are enclosed within the pockets by flaps 334 of the second layer 320. As shown in FIG. 3A, the flaps 334 overlap the first layer 310 at the top portion 314, such that the first layer 310 is positioned between the flaps 334 and the second layer 320. The flaps may then be secured with stiches 336, additional welds, and / or other fasteners such as adhesives or rivets. In the embodiment of FIGs. 3A-3B, the second layer 320 includes four flaps 334. In other embodiments, a single flap may be used, or two flaps may be used. In some other embodiments, a backpack frame system may not include flaps, and the rods 332A-332D may be secured in the pockets 330A-330D by a thermal bond, stitching, or adhesive closing the open end of the pockets 330A-330D.

[0062] FIGs. 4A-4E depict a process of manufacturing a backpack frame system according to some embodiments. The steps or portions of the steps of FIGs. 4A-4E may be changed in order in some cases, or may be omitted entirely (e.g., optional). FIGs. 4A-4E demonstrate the simplicity of the manufacture of a backpack frame system of exemplary embodiments herein.

[0063] FIG. 4A is a front elevation view depicting a first stage in a method for forming a backpack frame system 400 in accordance with some embodiments of the present invention. As show n in FIG. 4A, a first layer 410 and a second layer 420 of weldable or thermally bondable material are provided, with the second layer 420 underlaying the first layer. The first layer 410 includes four column portions 412A-412D, and the second layer 420 includes four column portions aligned with Attorney Docket No 55656-10370 those of the first layer. A top horizontal portion 414 and a bottom horizontal portion of the first layer interconnect the first layer column portions. Likewise, a top horizontal portion 422 and a bottom horizontal portion 424 of the second layer interconnect the second layer column portions. Intermediate horizontal portions 426A-G further interconnect the second layer column portions. The second layer includes flaps 434 attached to the top portion 422 that extend above the top portion 414 of the first layer 410.

[0064] As show n in FIG. 4A, with the first layer 410 overlaid on the second layer 420 and aligned, a single w elding or thermal bonding operation may join the first layer to the second layer in most all overlapping portions. However, pockets 430A-430D aligned with the overlapping column portions are omitted from the single welding or thermal bonding operation. As a result, an integrated structure is formed including two layers and four vertical pockets 430A-430D.

[0065] In FIG. 4B, after the pockets 430A-430D are formed, accessory straps and harnessing systems may be attached to the integral two-layer structure. For example, as shown in FIG. 4B, a strap 460 with buckle 462 may be attached to the first layer 410 via stitching (e.g., automated stitching). Waist padding 464 may be similarly attached to the first layer via stitching (e.g., automated stitching). Additionally, a hook and loop fastener pad 466 may be attached to a central accessory' column portion 428 of the second layer 420, which may form the basis of an adjustable yoke for backpack straps as described in the ‘777 Patent. Additional items may be attached at this stage, if desired.

[0066] In FIG. 4C, three horizontal stays 440A-440C may be attached to the integral two-layer structure. As shown in FIG. 4C, the stays may be aligned with the intermediate connecting portions and the top portion 422 of the second layer 420. In some cases, the horizontal stays may not overlap the outermost pockets 430A, 430D, which may improve flexibility and comfort of the frame. The horizontal stays may be attached to the second layer 420 via a welding process, adhesives or stitching. The horizontal stays may be aligned with the various interconnecting portions of the second layer 420, for example, the top portion 422 and intermediate portions 426A, 426B. Such alignment may enable rapid production of the pack, as the location of the horizontal stays is easy to determine based on the pattern of the second layer 420. In some embodiments, the horizontal stays may include a fabric pocket housing a rod. The pocket may be formed by stitching, by welding, or another thermal bonding process. In the case of welding or thermally bonding, the horizontal stays may also include two layers of weldable or thermally bondable material. The rod may be formed of pultruded polyurethane-infused glass fiber. Attorney Docket No 55656-10370

[0067] In FIG. 4D, vertical support stay rods 432 are inserted into each of the pockets 430A-430D formed between the first layer 410 and the second layer 420. The rods may be formed of pultruded polyurethane-infused glass fiber. The pockets are formed by the welding or thermal bonding process discussed above.

[0068] In FIG. 4E. the flaps 434 are folded over the top portion 414 of the first layer 410 to close the pockets 430A-430D. Accordingly, the flaps retain the rods 432 within the respective pockets. The flaps may be fixed in place on the first layer 410 with stitches 436 as shown in FIG. 4E. In other embodiments, a second welding process may be employed.

[0069] FIG. 5 is a flow' diagram for a method of forming a backpack frame system in accordance with some embodiments of the present invention. In block 500, the method includes cutting a first layer of weldable or thermally bondable material, where the cut first layer includes at least two column portions, a top horizontal portion connecting the at least tw o column portions, and a bottom horizontal portion connecting the at least two column portions. The first layer may be die cut or laser cut, for example. In block 502, the method includes cutting a second layer of weldable or thermally bondable material, where the cut second layer includes at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, and at least two intermediate horizontal portions connecting the at least two column portions betw een the top horizontal portion and the bottom horizontal portion. In block 504, the method includes welding the first layer and the second layer together to form at least two pockets in the at least two column portions. In block 506, the method includes attaching at least two horizontal stays to the at least two intermediate horizontal portions of the second layer. For example, the attachment may be by sew ing, w elding, or another thermal bonding process. In block 508, the method includes inserting a rod into each of the at least two pockets. In block 510, the method includes folding at least one flap of the second layer over the first layer to close the at least two pockets.

[0070] FIG. 6 is a perspective view of the backpack frame system 300 of FIG. 3A. As discussed above with reference to FIG. 3A, the backpack frame system 300 includes a first layer of weldable or thermally bondable material 310 and a second layer of weldable or thermally bondable material 320. The first layer 310 and the second layer 320 may be joined together (e.g., thermally bonded) to form an integral structure, as discussed further with reference to FIG. 4A. Together the first layer 310 and the second layer 320 form a lattice structure that forms the basis of the backpack frame system. The first layer 310 includes four column portions 312A, 312B, 312C, 312D that Attorney Docket No 55656-10370 correspond to column portions of the second layer 320, though in other embodiments more or fewer column portions may be employed, for example, at least two column portions. The first layer further includes a top horizontal portion 314 and a bottom horizontal portion 316 that interconnect the four columns 312A, 312B, 312C, 312D. The second layer further includes a top horizontal portion 322 and a bottom horizontal portion 324, which interconnect the of the second layer and are generally aligned with the top and bottom portions of the first layer 310. The first layer 310 and the second layer 320 together form a plurality of pockets configured to capture rods. The rods provide structure to the fabnc layers, forming a frame that is able to transfer load vertically as part of a backpack. In the example of FIG. 6, the backpack frame system 300 may include four vertical stay rods, one for each column portion.

[0071] As discussed above, the backpack frame system 300 has advantages in its construction compared to prior frame systems like that of the ‘777 Patent. That is, the combination of the thermally bonded layers and the vertical rods of specific geometries and materials yields a frame that has better performance than prior frames and is easier to manufacture. While the individual aspects of the backpack frame construction described herein have their own benefits individually, in combination the backpack frame system 300 is transversally, torsionally (e.g., about dash-dot axis A), and vertically (e.g., about dash-double-dot axis B) stiffer than frames assembled using traditional fabrics and sewing techniques. For example, the backpack frame system 300 may flex approximately 37% less under force Fi generating a torsional torque Ti about axis A compared to the backpack frame system of the ‘777 Patent. Such an improvement may be representative of the backpack frame’s 300 efficiency in transferring load to a wearer when walking. Accordingly, the backpack frame system 300 provides more efficient transfer of energy between a backpack load and a wearer than prior backpack frame systems. As another example, the backpack frame system may flex less under force F2 generating bending torque T2 about axis B, compared to the backpack frame system of the ‘777 Patent. Such an improvement may be representative of the vertical load carrying capacity. Accordingly, the backpack frame system 300 may be subject to higher loads before deformation compared to prior backpack frame systems.

[0072] As discussed above, the rods employed in the backpack frame system 300 may also be formed of different materials and have different geometries compared to prior backpack frame systems. In some embodiments, the rods may be formed of pultruded polyurethane-infused glass fiber, which may have improved performance characteristics over prior rods in backpack frame systems. This pultruded polyurethane-infused glass fiber may be less brittle at very cold Attorney Docket No 55656-10370 temperatures. Additionally, this pultruded polyurethane-infused glass fiber may be able to accommodate higher deflection before failure over prior rods. In other embodiments, other materials may be employed in connection with backpack frame systems described herein, as the present disclosure is not so limited. In addition to materials, the rods may also have a cylindrical geometry, which contracts with the flattened rods of prior backpack frame systems. Such an arrangement improves stiffness in certain directions compared with the flattened rods of prior backpack frame systems, as the rods exhibit consistent flex profiles in all directions. Specifically, the cylindrical rods may be stiffer than prior flattened rods in vertical load bearing stiffness (e.g., bending about axis B), compared with prior backpack frame systems. In some embodiments, the vertical say rods and horizontal stay rods may be formed of the same material and have the same geometry. In some embodiments, a rod for a backpack frame system may have a diameter between 0.15 inches and 0.35 inches, 0.20 inches and 0.30 inches, as well as preferably between 0.22 inches and 0.28 inches. In some embodiments, a vertical stay rod for a backpack frame system may have a length between 17 inches and 24 inches, 18 inches and 23 inches, as well as preferably between 19 inches and 21 inches.

[0073] FIG. 7 is a front view of a rod subassembly 600 for a backpack frame system, and FIG. 8 is a cross-sectional view of the rod subassembly 600 of FIG. 7 taken along line 8-8. As shown in FIGs. 7-8, the rod subassembly includes a rod 602 and a cap 604. The rod 602 is cylindrical, and is configured to be press-fit into a cylindrical receptacle formed in the cap 604. As shown in FIG. 8, the rod 602 may be solid throughout. In some other embodiments, the rod 602 may be tubular. The rod 602 may be formed of pultruded polyurethane glass fiber. In some embodiments, the rod 602 may have an edge 608 formed at the end of the rod. The edge 608 may be a 90° edge formed by cutting the rod 602 to its desired length. In some cases, this edge 608 may be abrasive when in contact with fabric, such as material layers forming pockets in a backpack frame system. Accordingly, the cap 604 includes a rounded surface 606 configured to cover the edge 608 and provide a smooth surface in contact with any fabric materials of a backpack frame system. The rounded surface 606 may reduce the amount of wear between the rod 602 and the pockets of a backpack frame system, thereby improving the durability and longevity of the backpack frame system. Furthermore, the caps 604 may provide a buffer space between the rods 602 and the pocket, thereby reducing friction and allowing the rods to rotate more freely within the pockets. As the caps 604 have an outer diameter greater than that of an outer diameter of the rod 602, the cap 604 may be configured to engage the interior of a pocket, creating a gap between the interior of the pocket and the rod 602 at least in the region of the cap 604. In this manner, contact between Attorney Docket No 55656-10370 the rod 602 and the pocket interior is reduced, thereby reducing friction between the rod 602 and the pocket interior. The caps 604 may be formed of a low-friction plastic material such as nylon (e.g., PA66), though other materials may be used in other embodiments. The cap 604 may include an indent 610 formed at an end of the cap 604. In some embodiments, a rod subassembly may include a single rod with two caps, one at each end.

[0074] FIGs. 9-1 1 depict front schematics of yokes 700, 800, 900 for a backpack frame system in accordance with some embodiments of the present invention. As noted above, in prior backpack frame systems like in the ‘777 Patent, a frame may be coupled with an adjustable harnessing system, allowing the backpack frame to be worn by a wide variety of users. However, conventional backpack frame systems have struggled to adapt to a wide variety of body types for both men and women in a military context. The inventors have appreciated a frame that may be a single size and connected to the one or more adjustable yokes 700, 800, 900 providing a range of adjustability to the backpack frame system beyond conventional strap size adjustment. Specifically, the inventors have appreciated that three differently sized yokes 700, 800, 900 provide appropriate size adjustment for military men and women in the 2ndto 98thpercentile in size.

[0075] As shown in FIGs. 9-11, the yokes each include an adjustment plate 702, 802, 902 and a strap junction 704, 804, 904. The strap junctions are each connected to two backpack straps 706, 806, 906. The adjustment plates 702, 802, 902 are each configured to be releasably coupled to a backpack frame system. The length of the adjustment plates 702, 802, 902 provides a vertical adjustment of the backpack straps with respect to the backpack frame system. In particular, the adjustment plate 702 of the small yoke 700 has a range of adjustment Ri of between 14 inches and 18 inches measured from the bottom of a backpack frame system (e.g., backpack frame system 300 of FIG. 3A) to a top of the strap junction 704 (e.g., the lowermost portion of the “U"’ formed between the backpack straps 706). The adjustment plate 802 of the medium yoke 800 has a range of adjustment R2 of between 16 inches and 20 inches measured from the bottom of a backpack frame system (e.g., backpack frame system 300 of FIG. 3A) to atop of the strap junction 804 (e.g., the lowermost portion of the “U” formed between the backpack straps 806). The adjustment plate 902 of the large yoke 900 has a range of adjustment Rs of between 19 inches and 24 inches measured from the bottom of a backpack frame system (e.g., backpack frame system 300 of FIG. 3 A) to a top of the strap junction 904 (e.g., the lowermost portion of the ‘"U” formed between the backpack straps 906). Accordingly, an overall vertical adjustment provided by the yokes may be between 16 inches and 24 inches (e.g., 8 inches of total adjustability). Attorney Docket No 55656-10370

[0076] In addition to the vertical adjustability, the inventors have also appreciated that the angle of the aperture between backpack straps 706, 806, 906 is important for wearer comfort and for fit across a wide range of body types, particularly when plate carriers or other accessories are worn in a military context. For example, past backpacks have wide backpack strap apertures that may result in straps slipping off of the top of plate carriers. Additionally, past backpacks may have a single aperture angle across multiple sizes, which may not be ideal for wearer comfort. As shown in FIGs. 9-11, the inventors have appreciated backpack strap aperture angles allow the yokes 700, 800, 900 to fit an appropriate subset of body sizes. In FIGs. 9-11, a conventional yoke is shown in phantom to illustrate the improvement in sizing. In the example depicted, the yoke aperture angle a is approximately 76° measured between an innermost edge of each strap across all sizes of yokes. In FIG. 9, the small yoke 700 has a yoke aperture angle Pi of approximately 60°. In FIG. 10, the medium yoke 800 has ayoke aperture angle 2 of approximately 65°. In FIG. 11, the medium yoke 900 has a yoke aperture angle ? of approximately 70°. In some embodiments, a yoke for a backpack frame system may have a yoke aperture angle between 55° and 75°, or preferably between 60° and 70°. Accordingly, in the example shown, all yokes have ayoke aperture angle of less than that of the conventional yokes shown (e.g.. a yoke aperture angle of 76°).

[0077] In some embodiments, the yokes 700. 800, 900 may be coupled with waist belt adjustability appropriate to the subset of the body sizes the yoke is configured for. In some embodiments, the small yoke 700 may be associated with a waist circumference adjustment of 25-32 inches, the medium yoke 800 may be associated with a waist circumference adjustment of 28-37 inches, and the large yoke 900 may be associated with a waist circumference adjustment of 31-42 inches, respectively.

[0078] The present disclosure is disclosed above and in the accompanying drawings with reference to a variety of examples. The purpose served by the disclosure, however, is to provide examples of the various features and concepts related to the disclosure, not to limit the scope of the disclosure. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the examples described above without departing from the scope of the present disclosure.

Claims

Attorney Docket No 55656-10370CLAIMSWhat is claimed is:

1. A backpack frame system comprising: a first layer of thermally bondable material including at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions; a second layer of thermally bondable material including at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, at least two intermediate horizontal portions connecting the at least two column portions between the top honzontal portion and the bottom horizontal portion, and at least one top flap, wherein the second layer is thermally bonded to the first layer; pockets positioned in between the at least two column portions of the first layer and the at least two column portions of the second layer, and rods positioned in the pockets, wherein the rods are retained in the pockets by the at least one top flap extending over the first layer.

2. The backpack frame system of claim 1, further comprising a plurality' of horizontal stays attached to the second layer on the at least two intermediate horizontal portions of the second layer.

3. The backpack frame system of claim 2, wherein the plurality of horizontal stays are thermally bonded to the second layer.

4. The backpack frame system of claim 1, wherein the first layer and the second layer are composed of polyurethane-coated fabric.

5. The backpack frame system of claim 1, wherein the rods are formed of pultruded polyurethane-infused glass fiber.

6. The backpack frame system of claim 1, wherein the at least one top flap is stitched to the first layer to enclose the pockets.Attorney Docket No 55656-103707. The backpack frame system of claim 1, wherein the rods are cylindrical.

8. The backpack frame system of claim 1, wherein the rods include caps positioned on the end of each rod, wherein the caps have a rounded end portion.

9. The backpack frame system of claim 8, wherein the caps are configured to reduce contact between the rods and the pockets to reduce friction between the rods and the pockets.

10. The backpack frame system of claim 1, further comprising a yoke attached to either the first layer or the second layer, wherein the yoke has a yoke aperture angle between 60° and 70°.

11. The backpack frame system of claim 1, further comprising a yoke releasably coupled to either the first layer or the second layer, wherein the yoke is moveable relative to the first layer or the second layer in a range between 16 and 24 inches measured from a bottom of the first layer to a top of a yoke junction of the yoke.

12. A method of manufacturing a backpack frame system, the method comprising the steps of: cutting a first layer of thermally bondable material, where the cut first layer includes at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions; cutting a second layer of thermally bondable material, where the cut second layer includes at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, and at least two intermediate horizontal portions connecting the at least two column portions between the top horizontal portion and the bottom horizontal portion; thermally bonding the first layer and the second layer together to form at least two pockets in the at least two column portions; attaching at least two horizontal stays to the at least two intermediate horizontal portions of the second layer; inserting a rod into each of the at least tw o pockets; and folding at least one flap of the second layer over the first layer to close the at least two pockets.Attorney Docket No 55656-1037013. The method of claim 12, wherein the first layer and the second layer are composed of polyurethane-coated fabric.

14. The method of claim 12, wherein the rods are formed of pultruded polyurethane-infused glass fiber.

15. The method of claim 12, wherein thermally bonding the first layer and the second layer includes dielectrically welding the first layer and the second layer.

16. The method of claim 12, further comprising attaching a plurality of horizontal stays attached to the second layer on the at least two intermediate horizontal portions of the second layer.

17. The method of claim 16, wherein attaching the plurality of horizontal stays comprises thermally bonding the horizontal stays to the second layer.

18. The method of claim 12, further comprising stitching the at least one top flap to the first layer to close the at least two pockets.

19. The method of claim 12, further comprising attaching a yoke to either the first layer or the second layer, wherein the yoke has a yoke aperture angle between 60° and 70°.

20. The method of claim 12, further comprising releasably coupling a yoke to either the first layer or the second layer, wherein the yoke is moveable relative to the first layer or the second layer in a range between 16 and 24 inches measured from a bottom of the first layer to a top of a yoke junction of the yoke.

21. A backpack frame system comprising: a first layer of polyurethane-coated fabric including at least two column portions, a top horizontal portion connecting the at least two column portions, and a bottom horizontal portion connecting the at least two column portions; a second layer of polyurethane-coated fabric including at least two column portions, a top horizontal portion connecting the at least two column portions, a bottom horizontal portion connecting the at least two column portions, at least two intermediate horizontal portionsAttorney Docket No 55656-10370 connecting the at least two column portions between the top horizontal portion and the bottom horizontal portion, wherein the second layer is joined with the first layer; pockets positioned in between the at least two column portions of the first layer and the at least two column portions of the second layer; and rods formed of pultruded polyurethane-infused glass fiber positioned in the pockets.

22. The backpack frame system of claim 21, wherein the first layer and the second layer are thermally bonded together to form an integrated structure.

23. The backpack frame system of claim 21. further comprising a plurality of horizontal stays attached to the second layer on the at least two intermediate horizontal portions of the second layer.

24. The backpack frame system of claim 23, wherein the plurality of horizontal stays are thermally bonded to the second layer.

25. The backpack frame system of claim 21, wherein the rods are cylindrical.

26. The backpack frame system of claim 21, wherein the rods include caps positioned on the end of each rod, wherein the caps have a rounded end portion.

27. The backpack frame system of claim 26, wherein the caps are configured to reduce contact between the rods and the pockets to reduce friction between the rods and the pockets.

28. The backpack frame system of claim 21, further comprising a yoke attached to either the first layer or the second layer, wherein the yoke has a yoke aperture angle between 60° and 70°.

29. The backpack frame system of claim 21, further comprising a yoke releasably coupled to either the first layer or the second layer, wherein the yoke is moveable relative to the first layer or the second layer in a range between 16 and 24 inches measured from a bottom of the first layer to a top of a yoke junction of the yoke.

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