Backpack external frame and suspension system

FIELD

The present disclosure relates to an external frame and suspension system for a backpack.

BACKGROUND

Backpacks generally fall into one of three categories: frameless, external frame, and internal frame. External and internal frames generally serve to support a load and distribute the weight of the load across the wearer's body. External frames generally are designed to carry heavier loads and thus provide the wearer more support and better weight distribution than internal frames or frameless packs. However, the increased strength of external frames generally increases the weight of external frames.

SUMMARY

Examples of the disclosure may include a backpack. In some examples, the backpack includes an external frame. The external frame may include a pair of upright members (or stays) and a pair of cross members (or stays). The pair of cross members may extend transversely to, and may be attached to, the pair of upright members. The pair of upright members and the pair of cross members may be constructed of a laminate structure having layers of carbon fiber and wood. The laminate structure of the pair of upright members and the pair of cross members may provide advantages relative to conventional external frames. For example, the laminate structure of the upright members and the cross members may result in significant weight savings relative to conventional external frames, without sacrificing strength.

The backpack may include a sleeve positioned around each upright member of the pair of upright members. The pair of sleeves may extend along a majority of the length of the pair of upright members. Each sleeve may be attached to a respective upright member by the attachment of the pair of cross members to the pair of upright members.

The backpack may include a torso pad attached to each sleeve. Each torso pad may be moveable relative to the pair of upright members. For example, each torso pad may be pivotable, laterally translateable, or both relative to the pair of upright members.

The backpack may include a shoulder strap attached to each sleeve. A portion of each shoulder strap may be slideably retained between a respective torso pad and sleeve. Each shoulder strap may include padded section for contact against a shoulder of a wearer.

The backpack may include a waist belt removeably attached to the pair of upright members. The waist belt may include an intermediate segment and a pair of padded end segments extending outwardly from the intermediate segment. The intermediate segment may define a pair of pockets that receive lower ends of the pair of upright members.

The backpack may include a lumbar pad attached to one of the pair of cross members. The lumbar pad may be folded around the intermediate segment of the waist belt and may be attached to the pair of upright members to vertically restrain the waist belt relative to the external frame. The lumbar pad may laterally restrain the waist belt relative to the external frame by maintaining lower ends of the pair of upright members in the pair of pockets. The lumbar pad may be thicker than the pair of padded end segments of the waist belt.

The pair of cross members may include an upper cross member and a lower cross member spaced apart from the upper cross member. The pair of upright members may converge toward one another as the pair of upright members extends downwardly from the upper cross member to the lower cross member. The pair of upright members may extend above the upper cross member to facilitate attachment of a bag to the external frame. The pair of upright members may extend below the lower cross member to facilitate attachment of a waist belt to the external frame. The external frame may be narrower in width than a wearer's back. The pair of upright members may have curved profiles. The pair of upright members and the pair of cross members may have rectangular cross sections and may be referred to as bars. The pair of upright members and the pair of cross members may be attached together by four, one-degree-of-freedom joints to permit relative lateral movement of the external frame.

Examples of the disclosure may include a method of assembling a backpack having an external frame and a suspension system. In some examples, the method includes positioning a sleeve having a closed end and an open end over an upright member of the external frame, positioning a cross member of the external frame transversely to the upright member such that a portion of the sleeve extends between the cross member and the upright member, and attaching the cross member to the upright member such that the sleeve is trapped between the cross member and the upright member. The upright member and the cross member may be constructed of a laminate structure having layers of carbon fiber and wood. The method may include attaching a torso pad to the sleeve such that the torso pad is pivotable relative to the upright member.

This summary of the disclosure is given to aid understanding, and one of skill in the art will understand that each of the various aspects and features of the disclosure may advantageously be used separately in some instances, or in combination with other aspects and features of the disclosure in other instances. Accordingly, while the disclosure is presented in terms of examples, it should be appreciated that individual aspects of any example can be claimed separately or in combination with aspects and features of that example or any other example. The present disclosure is set forth in various levels of detail in this application and no limitation as to the scope of the claimed subject matter is intended by either the inclusion or non-inclusion of elements, components, or the like in this summary.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate examples of the disclosure and, together with the general description given above and the detailed description given below, serve to explain the principles of these examples.

<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of an example backpack.

<figref idref="DRAWINGS">FIG. 2</figref> is a side elevation view of the backpack of <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 3</figref> is an exploded view of the backpack of <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 4</figref> is a perspective view of an example external frame with sleeves positioned around the upright members of the frame.

<figref idref="DRAWINGS">FIG. 5</figref> is an enlarged view of an intersection of an upright member and a cross member of the external frame of <figref idref="DRAWINGS">FIG. 4</figref> taken along the detail line <b>5</b>-<b>5</b> illustrated in <figref idref="DRAWINGS">FIG. 4</figref>.

<figref idref="DRAWINGS">FIG. 6</figref> is a cross-section view of the intersection of the upright member and the cross member of <figref idref="DRAWINGS">FIG. 5</figref> taken along the line <b>6</b>-<b>6</b> illustrated in <figref idref="DRAWINGS">FIG. 5</figref>.

<figref idref="DRAWINGS">FIG. 7</figref> is a schematic view of a laminate structure of the upright members, the cross members, or both of the external frame <figref idref="DRAWINGS">FIG. 3</figref>.

<figref idref="DRAWINGS">FIG. 8</figref> is a cross-section view of a torso pad of the backpack of <figref idref="DRAWINGS">FIG. 1</figref> taken along the line <b>8</b>-<b>8</b> illustrated in <figref idref="DRAWINGS">FIG. 2</figref>.

<figref idref="DRAWINGS">FIG. 9</figref> is a schematic cross-sectional view of the torso pads of the backpack of <figref idref="DRAWINGS">FIG. 1</figref> pivoted into alignment with a contour of a wearer's back.

<figref idref="DRAWINGS">FIG. 10</figref> is a partial cross-sectional view of a lumbar pad of the backpack of <figref idref="DRAWINGS">FIG. 1</figref>.

<figref idref="DRAWINGS">FIG. 11</figref> is a cross-section view of the lumbar pad of <figref idref="DRAWINGS">FIG. 10</figref> taken along the line <b>11</b>-<b>11</b> illustrated in <figref idref="DRAWINGS">FIG. 15</figref>.

<figref idref="DRAWINGS">FIG. 12</figref> is a perspective view of the backpack of <figref idref="DRAWINGS">FIG. 1</figref> with a chair removeably attached to the upright members and to the lumbar pad.

<figref idref="DRAWINGS">FIG. 13A</figref> is a schematic view of a common loop and a three-bar slider prior to attachment to one another.

<figref idref="DRAWINGS">FIG. 13B</figref> is a schematic view of the common loop and the three-bar slider of <figref idref="DRAWINGS">FIG. 15</figref> removeably attached to one another.

<figref idref="DRAWINGS">FIG. 14</figref> is a fragmentary, perspective view of a bag positioned onto upper ends of the external frame of <figref idref="DRAWINGS">FIG. 4</figref>.

<figref idref="DRAWINGS">FIG. 15</figref> is a rear elevation view of the backpack of <figref idref="DRAWINGS">FIG. 1</figref> situated on a wearer's back.

In certain instances, details that are not necessary for an understanding of the disclosure or that render other details difficult to perceive may have been omitted. In the appended drawings, similar components and/or features may have the same reference label. It should be understood that the claimed subject matter is not necessarily limited to the particular examples or arrangements illustrated herein.

DETAILED DESCRIPTION

Referring to <figref idref="DRAWINGS">FIGS. 1-3</figref>, a backpack <b>100</b> including an external frame <b>102</b> and a suspension system <b>104</b> is provided. The external frame <b>102</b> generally serves to support a load and, along with the suspension system <b>104</b>, to distribute most of the weight of the load to the wearer's hips and legs, thereby improving the wearer's ability to carry heavy loads and increasing the agility and balance of the wearer when carrying the load. The external frame <b>102</b> and suspension system <b>104</b> generally disperse the load onto the skeletal structure of the wearer in a balanced way, thereby reducing or eliminating forward, aft, right, or left forces on the wearer's body so as to not disturb the wearer's natural posture, balance, and movement.

Referring to <figref idref="DRAWINGS">FIGS. 3 and 4</figref>, the external frame <b>102</b> may include four frame members or stays: a pair of upright members <b>106</b>, <b>108</b> and a pair of cross members <b>110</b>, <b>112</b>. The upright members <b>106</b>, <b>108</b>, also referred to as upright stays, may be spaced laterally apart from one another and may extend upwardly along a wearer's back <b>114</b> (see <figref idref="DRAWINGS">FIG. 15</figref>). The cross members <b>110</b>, <b>112</b>, also referred to as cross stays, may be spaced vertically apart from one another and may extend laterally across a wearer's back <b>114</b>. The cross members <b>110</b>, <b>112</b> may extend transversely to the upright members <b>106</b>, <b>108</b> and may be positioned rearwardly of the upright members <b>106</b>, <b>108</b> relative to the wearer. An upper cross member <b>110</b> may be positioned proximate to upper ends <b>106</b><i>a</i>, <b>108</b><i>a </i>of the upright members <b>106</b>, <b>108</b> (see <figref idref="DRAWINGS">FIG. 4</figref>). A lower cross member <b>112</b> may be positioned proximate to the lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b>. As shown in <figref idref="DRAWINGS">FIG. 4</figref>, the lower cross member <b>112</b> may be spaced vertically above the lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b> such that the upright members <b>106</b>, <b>108</b> extend below the lower cross member <b>112</b> for attachment to a waist belt, which will be discussed in more detail below.

The cross members <b>110</b>, <b>112</b> may be attached to the upright members <b>106</b>, <b>108</b> at the intersection of the cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b>. With specific reference to <figref idref="DRAWINGS">FIGS. 4-6</figref>, a single fastener <b>116</b>, e.g., a rivet, may be used at each intersection to attach the cross members <b>110</b>, <b>112</b> to the upright members <b>106</b>, <b>108</b>, thus permitting slight angular movement between the upright members <b>106</b>, <b>108</b> and the cross members <b>110</b>, <b>112</b>. As such, the frame <b>102</b> may be slightly skewed from side-to-side by a load attached to the external frame <b>102</b>. Although not shown, more than one fastener may be used at each intersection to provide a more rigid connection between the cross members <b>110</b>, <b>112</b> to the upright members <b>106</b>, <b>108</b>.

Referring to <figref idref="DRAWINGS">FIGS. 3 and 4</figref>, the external frame <b>102</b> may resemble an inverted trapezoid when viewed from the front or rear. The upright members <b>106</b>, <b>108</b> may converge toward one another as the upright members <b>106</b>, <b>108</b> extend downwardly from the upper cross member <b>110</b> to the lower cross member <b>112</b>. In other words, the external frame <b>102</b> may taper in width from an upper end of the frame <b>102</b> to a lower end of the frame <b>102</b>. With reference to <figref idref="DRAWINGS">FIG. 15</figref>, the uprights may be positioned farther apart from one another near the shoulder region of a wearer's back and may be positioned closer to one another near the lumbar region of the wearer's back. In other words, the upright members <b>106</b>, <b>108</b> may converge toward one another as the upright members <b>106</b>, <b>108</b> extend downwardly from the shoulder region toward the wearer's hips, thereby transferring the load to the wearer's hips and legs. Although in <figref idref="DRAWINGS">FIGS. 3 and 4</figref> the external frame <b>102</b> has a linear taper from the upper end of the frame to the lower end of the frame when viewed from the front or rear, in some implementations the external frame <b>102</b> may have a non-linear taper when viewed from the front or rear.

To accommodate the larger width of the upper end <b>102</b><i>a </i>of the frame <b>102</b>, the upper cross member <b>110</b> may be longer than the lower cross member <b>112</b>. The upper and lower cross members <b>110</b>, <b>112</b> may extend parallel or substantially parallel to one another. The upper cross member <b>110</b> may form acute interior angles with the upright members <b>106</b>, <b>108</b>, and the lower cross member <b>112</b> may form obtuse interior angles with the upright members <b>106</b>, <b>108</b>.

Referring to <figref idref="DRAWINGS">FIGS. 1-4</figref>, the external frame <b>102</b> may have a curvilinear profile when viewed from the side. The upright members <b>106</b>, <b>108</b> may have an S-shaped profile that corresponds to a profile of the wearer's back <b>114</b>. The profile of the upright members <b>106</b>, <b>108</b> may be customized to accommodate various back profiles, such as a flat back or a standard-curved back. The cross members <b>110</b>, <b>112</b> may have a rectilinear profile and extend in a straight line between the upright members <b>106</b>, <b>108</b>.

The cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> of the external frame <b>102</b> may be constructed of bars, rods, tubes, or other members having various cross-sectional profiles. With reference to <figref idref="DRAWINGS">FIGS. 5 and 6</figref>, the cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> may be constructed of bars having rectangular cross-sections. In such examples, the cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> may be referred to as cross bars and upright bars, respectively. The cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> may have identical or substantially identical cross-sectional dimensions. In some implementations, the cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> have cylindrical cross-sections, oval cross-sections, trapezoidal cross-sections, or other suitable cross-sectional shapes.

The cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> of the external frame <b>102</b> may be constructed of carbon fiber, laminate, metal (e.g., aluminum), plastic, wood, or other suitable materials. Referring to <figref idref="DRAWINGS">FIG. 7</figref>, the external frame <b>102</b> may be constructed of a composite or laminate of carbon fiber and wood that is lightweight, yet provides high strength, thereby reducing the weight of the external frame <b>102</b> relative to conventional external frames <b>102</b> without sacrificing strength. The upright members <b>106</b>, <b>108</b> and the cross members <b>110</b>, <b>112</b> may be formed of the laminate structure. Referring to <figref idref="DRAWINGS">FIG. 7</figref>, the upright members <b>106</b>, <b>108</b> and the cross members <b>110</b>, <b>112</b> may include multiple layers of wood flanked by layers of carbon fiber. In some implementations, the upright members <b>106</b>, <b>108</b> and the cross members <b>110</b>, <b>112</b> include three layers of wood C, E, G stacked on top of one another and attached together with thermoplastic resin layers D, F. Carbon fiber layers A, I may be attached to outer surfaces of the outer wood layers C, G with thermoplastic resin layers B, H, which may be reinforced for increased stiffness. The thermoplastic resin layers B, H may include one ply of ninety-degree unidirectional fiberglass impregnated thermoplastic resin. The carbon fiber layers A, I may be constructed of two plies of unidirectional carbon fiber, which may be rotated ninety degrees relative to one another. The wood layers C, E, G may be formed of maple veneer or other suitable types of wood.

The wood layers C, E, G may be thicker than the carbon fiber layers A, I. For example, in some implementations, the wood layers C, E, G are 0.0625 inches in thickness and the carbon fiber layers A, I are 0.009 inches in thickness. The thermoplastic resin layers B, D, F, H may be the same thickness as the carbon fiber layers A, I. For example, in the above-noted implementations, the thermoplastic resin layers B, D, F, H may have a thickness of 0.009 inches. Although two layers of carbon fiber A, I and three layers of wood C, E, G are illustrated, the frame <b>102</b> may include more or less layers of carbon fiber and wood based on the desired strength and weight characteristics of the frame <b>102</b>.

The laminate structure of the upright members <b>106</b>, <b>108</b> and the cross members <b>110</b>, <b>112</b> of the external frame <b>102</b> may provide advantages relative to conventional external frames. For example, the laminate structure of the frame members <b>106</b>, <b>108</b>, <b>110</b>, <b>112</b> may result in significant weight savings relative to conventional external frames, without sacrificing strength. In some implementations, the external frame <b>102</b> with the laminate structure has about ten percent reduced weight relative to conventional external frames, yet is capable of supporting as much or more load relative to conventional external frames.

Referring to <figref idref="DRAWINGS">FIGS. 1-3</figref>, a suspension system <b>104</b> may be attached to the external frame <b>102</b>. The suspension system generally includes a system of straps and padding that softens the contact between the frame <b>102</b> and the wearer's back and provides attachment points for a bag or other items. The suspension system <b>104</b> may include a pair of sleeves <b>118</b>, <b>120</b>, a pair of torso pads <b>122</b>, <b>124</b>, a pair of shoulder straps <b>126</b>, <b>128</b>, a lumbar pad <b>129</b>, and a waist belt <b>130</b>. The suspension system <b>104</b> generally transfers the load to the wearer through the waist belt <b>130</b>, leaving the shoulder straps <b>126</b>, <b>128</b> primarily for stabilizing the load. Most of the weight is therefore taken off the wearer's shoulders, reducing the chance of injury from shoulder strap pressure, as well as being less restrictive of the wearer's upper body range of motion.

The pair of sleeves <b>118</b>, <b>120</b> may be positioned around the pair of upright members <b>106</b>, <b>108</b> and extend along a majority of the length of the upright members <b>106</b>, <b>108</b> continuously (see <figref idref="DRAWINGS">FIG. 4</figref>) or discontinuously. Referring to <figref idref="DRAWINGS">FIGS. 1-4</figref>, the sleeves <b>118</b>, <b>120</b> may be snugly fit onto the upright members <b>106</b>, <b>108</b>. The sleeves <b>118</b>, <b>120</b> may be closed at upper ends <b>118</b><i>a</i>, <b>120</b><i>a </i>and open at lower ends <b>118</b><i>b</i>, <b>120</b><i>b</i>. The sleeves <b>118</b>, <b>120</b> may enclose or surround a majority of the length of the upright members <b>106</b>, <b>108</b> (see <figref idref="DRAWINGS">FIG. 4</figref>). The sleeves <b>118</b>, <b>120</b> may extend from the upper cross member <b>110</b> to the lower cross member <b>112</b> and may be securely attached to the upright members <b>106</b>, <b>108</b> with the fasteners <b>116</b>. As shown in <figref idref="DRAWINGS">FIGS. 6 and 11</figref>, a portion of the sleeves <b>118</b>, <b>120</b> may be sandwiched between the cross members <b>110</b>, <b>112</b> and the upright members <b>106</b>, <b>108</b> at the intersection of the cross members <b>110</b>, <b>112</b> and upright members <b>106</b>, <b>108</b>.

With reference to <figref idref="DRAWINGS">FIG. 4</figref>, various attachments (e.g., fabric loops, common loops, three-bar sliders, and slider locks) may be stitched or otherwise attached to the sleeves <b>118</b>, <b>120</b> to provide attachment points for accessories, suspension components, or both. For example, the sleeves <b>118</b>, <b>120</b> may provide attachment points for a bag and a chair, both of which are described in more detail below. Additionally, the torso pads <b>122</b>, <b>124</b>, the shoulder straps <b>126</b>, <b>128</b>, and the lumbar pad <b>129</b> may be attached to the sleeves <b>118</b>, <b>120</b>. By providing attachments on the sleeves <b>118</b>, <b>120</b>, the cost and complexity of manufacturing the external frame <b>102</b> may be reduced, since the attachments may be attached to the sleeves <b>118</b>, <b>120</b> prior to fitting the sleeves <b>118</b>, <b>120</b> onto the upright members <b>106</b>, <b>108</b>, and, after attachment of the sleeves to the upright members, various accessories and suspension components may be interchangeably attached to the sleeves <b>118</b>, <b>120</b> via the attachment points.

The sleeves <b>118</b>, <b>120</b> may be constructed of various types of material. In some implementations, the sleeves <b>118</b>, <b>120</b> are constructed of webbing. The webbing may be formed of nylon, polypropylene, or other suitable materials. The webbing may be formed as a flat strip or a tube. In implementations using flat strip webbing, the webbing may be folded over onto itself and opposing, longitudinally-extending edges of the strip may be stitched together to form a shroud having an internal cavity with cross-sectional dimensions sufficient to receive the upright members <b>106</b>, <b>108</b>, and in some examples the sleeves <b>118</b>, <b>120</b> have a tight fit. The shroud may be closed at one end and open at the other end, thus permitting the shroud to be snugly slid onto a respective upright member <b>106</b>, <b>108</b> until the upper end <b>106</b><i>a</i>, <b>108</b><i>a </i>of the respective upright member <b>106</b>, <b>108</b> abuts against the closed end of the shroud. The attachment points of the suspension system <b>104</b> and accessories may be stitched into the seams of the folded-over strip of webbing or attached to a face of the webbing strips. In implementations using tube webbing, one end of the tube webbing may be closed by stitching, for example, and then snugly fit onto a respective upright member in the same manner described above with respect to the folded-over strip of webbing. In the tube webbing implementations, the attachment points of the suspension system <b>104</b> and accessories may be attached, such as stitched, to the outer surface of the tube webbing.

Referring to <figref idref="DRAWINGS">FIGS. 1-3</figref>, <b>8</b>, <b>9</b>, <b>12</b>, and <b>15</b>, the pair of torso pads <b>122</b>, <b>124</b> may be attached to the upright members <b>106</b>, <b>108</b> of the external frame <b>102</b>. With reference to <figref idref="DRAWINGS">FIGS. 8 and 9</figref>, the torso pads <b>122</b>, <b>124</b> each may include a foam pad <b>132</b> positioned within a housing <b>134</b>. In some implementations, the foam pad is constructed from polyethylene terephthalate (PET) closed-cell foam and is 0.75″ thick. The housing <b>134</b> may enclose the foam pad <b>132</b> and may include two strips of material, an outer strip <b>136</b> and an inner strip <b>138</b>, attached to one another along opposing sides <b>132</b><i>a</i>, <b>132</b><i>b </i>of the foam pad <b>132</b>. The outer strip of material <b>136</b> may be directed toward a wearer's back <b>114</b>, while the inner strip of material <b>138</b> may be directed toward the respective upright member <b>106</b>, <b>108</b> (see <figref idref="DRAWINGS">FIG. 8</figref>). In some implementations, the outer strip of material <b>136</b> is constructed of a moisture-control fabric, such as the fabric marketed under the Dri-Lex® brand. In some implementations, the inner strip of material is constructed of a durable fabric material that is tear and abrasion resistant, such as the fabric marketed under the Cordura® brand.

With continued reference to <figref idref="DRAWINGS">FIGS. 8 and 9</figref>, the housing <b>134</b> may be attached to a respective sleeve <b>118</b>, <b>120</b> with one or more strips of fabric material. In the depicted example, opposing side edges <b>140</b><i>a</i>, <b>140</b><i>b </i>of a single strip of material <b>140</b> are attached to the housing <b>134</b> at the junction of the outer and inner strips of material <b>136</b>, <b>138</b> along opposing sides <b>132</b><i>a</i>, <b>132</b><i>b </i>of the foam pad <b>132</b>. An intermediate section <b>140</b><i>c </i>of the single strip of material <b>140</b> may be attached to a respective sleeve <b>118</b>, <b>120</b> so as to connect the housing <b>134</b> to the sleeve <b>118</b>, <b>120</b> and thus to the associated upright member <b>106</b>, <b>108</b>. The inner strip of material <b>138</b> of the housing <b>134</b> and the single strip of material <b>140</b> may be joined together so as to define an open-ended, internal passage <b>142</b> peripherally-bounded by the strips <b>138</b>, <b>140</b>. In some implementations, the single strip of material <b>140</b> is constructed of a durable fabric material that is tear and abrasion resistant, such as the fabric marketed under the Cordura® brand.

Referring to <figref idref="DRAWINGS">FIG. 9</figref>, the pair of torso pads <b>122</b>, <b>124</b> may be moveable relative to the pair upright members <b>106</b>, <b>108</b> to provide a customized, comfortable fit. As shown in <figref idref="DRAWINGS">FIG. 9</figref>, the free spans <b>144</b>, <b>146</b> of the single strip of material <b>140</b> may permit the torso pads <b>122</b>, <b>124</b> to pivot and/or laterally translate relative to the pair of upright members <b>106</b>, <b>108</b>, thereby allowing the torso pads <b>122</b>, <b>124</b> to track the contour of a wearer's back <b>114</b> for increased comfort. Additionally, the motion of the torso pads <b>122</b>, <b>124</b> relative to the upright members <b>106</b>, <b>108</b> may maintain the torso pads <b>122</b>, <b>124</b> in contact with the wearer's back <b>114</b> during relative movement between the wearer and the external frame <b>102</b>, thereby providing flexibility to the backpack <b>100</b> and providing a more comfortable fit relative to conventional external frame backpacks.

The pair of shoulder straps <b>126</b>, <b>128</b> may be attached to the upright members of the external frame <b>102</b> and to the waist belt <b>130</b>. Referring to <figref idref="DRAWINGS">FIGS. 1 and 12</figref>, one end <b>126</b><i>a</i>, <b>128</b><i>a </i>of the shoulder straps <b>126</b>, <b>128</b> may be attached to a lower portion of the pair of sleeves <b>118</b>, <b>120</b> and an opposing end <b>126</b><i>b</i>, <b>128</b><i>b </i>of the shoulder straps <b>126</b>, <b>128</b> may be attached to the waist belt <b>130</b>. From the ends <b>126</b><i>a</i>, <b>128</b><i>a </i>of the shoulder straps <b>126</b>, <b>128</b> that are attached to the sleeves <b>118</b>, <b>120</b>, the shoulder straps <b>126</b>, <b>128</b> may pass through the internal passage <b>142</b> defined between the torso pads <b>122</b>, <b>124</b> and the upright members <b>106</b>, <b>108</b> and extend upwardly along the upright members <b>106</b>, <b>108</b> (see <figref idref="DRAWINGS">FIGS. 1 and 8</figref>). The shoulder straps <b>126</b>, <b>128</b> may be moveable, e.g., slideable, within the internal passage <b>142</b> relative to the torso pads <b>122</b>, <b>124</b> and the upright members <b>106</b>, <b>108</b>. Padded sections <b>148</b>, <b>150</b> of the shoulder straps <b>126</b>, <b>128</b> may define an apex of the shoulder straps <b>126</b>, <b>128</b> and may extend forwardly and downwardly from the apex. Adjustable, shoulder-pad lift straps <b>152</b>, <b>154</b> may attach at upper ends to the upper, closed end <b>118</b><i>a</i>, <b>120</b><i>a </i>of the sleeves <b>118</b>, <b>120</b> and may attach at lower ends to the padded sections <b>148</b>, <b>150</b> of the shoulder straps <b>126</b>, <b>128</b>. The lift straps <b>152</b>, <b>154</b> may lift the padded sections <b>148</b>, <b>150</b> of the shoulder straps <b>126</b>, <b>128</b> off of the top of a wearer's shoulder to prevent the weight of the backpack <b>100</b> and its supported load from pulling down on the top of the wearer's shoulders, thereby transferring the load primarily to the waist belt <b>130</b> through the external frame <b>102</b> and allowing the shoulder straps <b>126</b>, <b>128</b> to stabilize the load. The padded sections <b>148</b>, <b>150</b> of the shoulder straps <b>126</b>, <b>128</b> may be attached to one another with a buckle <b>156</b> (see <figref idref="DRAWINGS">FIG. 1</figref>). From the padded sections <b>148</b>, <b>150</b>, the shoulder straps <b>126</b>, <b>128</b> may extend downwardly and attach at terminal ends <b>158</b>, <b>160</b> to the waist belt <b>130</b> outwardly of the lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b>. These lower extensions <b>158</b>, <b>160</b> of the shoulder straps <b>126</b>, <b>128</b> defined between the padded sections <b>148</b>, <b>150</b> and the waist belt <b>130</b> may be adjustable in length to accommodate differently-sized wearers.

The waist belt <b>130</b> may extend transversely to, and may be attached to, the upright members <b>106</b>, <b>108</b> of the external frame <b>102</b>. Referring to <figref idref="DRAWINGS">FIGS. 1</figref>, <b>3</b>, <b>10</b>-<b>12</b>, and <b>15</b>, the waist belt <b>130</b> may include an intermediate segment <b>162</b> and a pair of padded end segments or wings <b>164</b> extending outwardly from the intermediate segment <b>162</b>. The intermediate segment <b>162</b> of the waist belt <b>130</b> may include a pair of cups <b>166</b>, <b>167</b> that define pockets <b>168</b> having open upper ends and closed lower ends. The pockets <b>168</b> may snugly receive lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b>, reducing or preventing lateral movement or slippage of the waist belt <b>130</b> relative to the frame <b>102</b>. The cups <b>166</b>, <b>167</b> may be constructed of a folded-over strip of material that is attached to a rear surface of the intermediate segment <b>162</b> of the waist belt <b>130</b>. The cup material may be formed of chlorosulfonated polyethylene (CSPE) synthetic rubber (CSM), such as that marketed under the Hypalon® brand, ballistic cloth, such as ballistic nylon, or other types of durable materials. The padded wings <b>164</b> may be selectively positionable around a wearer's hip or pelvic girdle, and ends of the padded wings <b>164</b> may be attached together with a releaseable buckle <b>170</b> (see <figref idref="DRAWINGS">FIG. 1</figref>). The waist belt <b>130</b> may be attached to the sleeves <b>118</b>, <b>120</b> and the lumbar pad <b>129</b> with adjustable straps.

The lumbar pad <b>129</b> may be attached to the lower cross member <b>112</b> and to the upright members <b>106</b>, <b>108</b> of the external frame <b>102</b> with a fabric covering <b>172</b>. Referring to <figref idref="DRAWINGS">FIGS. 10 and 11</figref>, the fabric covering <b>172</b> may include a rear flap <b>174</b> that includes a hemmed edge <b>175</b> that defines a passageway <b>176</b> that receives a portion of the lower cross member <b>112</b> spanning between the upright members <b>106</b>, <b>108</b> to secure the lumbar pad <b>129</b> to the lower cross member <b>112</b>. From the lower cross member <b>112</b>, the fabric covering <b>172</b> may extend downwardly along a rear side of the upright members <b>106</b>, <b>108</b>, may wrap around lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b>, may extend upwardly along a front side of the upright members <b>106</b>, <b>108</b>, and may be adjustably attached to the sleeves <b>118</b>, <b>120</b> with hook and look fasteners <b>178</b> threaded through a common loop <b>179</b>, for example. The intermediate segment <b>162</b> of the waist belt <b>130</b> may be sandwiched between the upright members <b>106</b>, <b>108</b> and the fabric covering <b>172</b> of the lumbar pad <b>129</b>, thereby restraining vertical movement of the waist belt <b>130</b> relative to the external frame <b>102</b> by forcing the cups <b>166</b>, <b>167</b> upwardly into engagement with the lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b>.

One or more foam pads <b>180</b>, <b>182</b> may be positioned along the front side of the upright members <b>106</b>, <b>108</b> and may be enclosed within the fabric covering <b>172</b> of the lumbar pad <b>129</b>. Referring to <figref idref="DRAWINGS">FIGS. 10 and 11</figref>, the lumbar pad <b>129</b> may include two foam pads <b>180</b>, <b>182</b> positioned one in front of the other within the fabric covering <b>172</b>. A rearwardly-positioned foam pad <b>180</b> may be thinner than a forwardly-positioned foam pad <b>182</b>. In some implementations, the rearwardly-positioned foam pad <b>180</b> may be 0.75″ thick, and the forwardly-positioned foam pad <b>182</b> may be 1.5″ thick. The rearwardly-positioned foam pad <b>180</b> may be constructed of a different type of foam than the forwardly-positioned foam pad <b>182</b>. In some implementations, the rearwardly-positioned foam pad <b>180</b> may be constructed of closed-cell foam, and the forwardly-positioned foam pad <b>182</b> may be constructed of open-cell foam for moisture-control purposes. For example, the open-cell foam may absorb moisture, e.g., sweat, from the lumbar region of the wearer during use. In some implementations, the rearwardly-positioned foam pad <b>180</b> may be formed of polyethylene terephthalate (PET) and may include a pressure-sensitive adhesive (PSA). In some implementations, the forwardly-positioned foam pad <b>182</b> may be formed of polyethersulfone (PES) with a UL temperature index.

Referring to <figref idref="DRAWINGS">FIGS. 1 and 15</figref>, the width of the lumbar pad <b>129</b> may be slightly larger than the separation distance between the lower ends <b>106</b><i>b</i>, <b>108</b><i>b </i>of the upright members <b>106</b>, <b>108</b>. The width of the lumbar pad <b>129</b> may provide a tighter wrap of the waist belt <b>130</b> around the wearer's hip girdle and waist, thereby providing a more comfortable attachment with reduced slippage of the external frame <b>102</b> relative to wearer, especially under heavy loads. The lumbar pad <b>129</b> also may be thicker than the padded end segments <b>164</b> of the waist belt <b>130</b>, thereby maintaining the external frame on the wearer's waist for effective load transfer to the wearer's hips and legs. The torso pads <b>122</b>, <b>124</b> and the lumbar pad <b>129</b> may provide a standoff between the external frame <b>102</b> and the wearer's back <b>114</b> to permit air flow between the frame <b>102</b> and the wearer's back <b>114</b> for cooling purposes. Further, the torso pads <b>122</b>, <b>124</b> and the lumbar pad <b>129</b> may prevent contact between the external frame <b>102</b> and the wearer's back <b>114</b> to provide a comfortable packing experience.

The external frame <b>102</b> and suspension system <b>104</b> may provide for quick attachment and detachment of various accessories, for example, shelves or bags. Referring to <figref idref="DRAWINGS">FIG. 12</figref>, a chair or shelf <b>184</b> may be attached to the external frame <b>102</b> by attaching an inner end <b>184</b><i>a </i>of the chair <b>184</b> to a pair of common loops <b>186</b> stitched to the rear flap <b>174</b> of the lumbar pad <b>129</b>. Support straps <b>188</b> may extend from the outer end <b>184</b><i>b </i>of the chair <b>184</b> and may be attached to the sleeves <b>118</b>, <b>120</b> using triangular loops <b>190</b> stitched to the sleeves <b>118</b>, <b>120</b>. With reference to <figref idref="DRAWINGS">FIGS. 13A and 13B</figref>, an example of the connection of the inner end <b>184</b><i>a </i>of the chair <b>184</b> to the rear flap <b>174</b> of the lumbar pad <b>129</b> is provided. A three-bar slider <b>192</b> may be attached to the chair <b>184</b> with a strip of webbing <b>194</b>. To attach the three-bar slider <b>192</b> to the common loop <b>186</b> (which is attached to the rear flap <b>174</b> of the lumbar pad <b>129</b> with a fabric loop <b>196</b>), the three-bar slider <b>192</b> may be rotated ninety-degrees relative to the common loop <b>186</b> such that the smaller dimension of the three-bar slider <b>192</b> is aligned with the internal through-hole of the common loop <b>186</b>. Once aligned, the three-bar slider <b>192</b> may be inserted through the through-hole of the common loop <b>186</b> and rotated back to its nominal orientation to interlock the three-bar slider <b>192</b> and the common loop <b>186</b>, as shown in <figref idref="DRAWINGS">FIG. 13B</figref>. To detach the three-bar slider <b>192</b> from the common loops <b>186</b>, thereby detaching the inner end <b>184</b><i>a </i>of the chair <b>184</b> from the lumbar pad <b>129</b>, the above steps may be performed in reverse order.

Referring to <figref idref="DRAWINGS">FIG. 14</figref>, a bag <b>198</b> may be attached to the external frame <b>102</b> by positioning a cradle <b>200</b> of the bag <b>198</b> over the upper cross member <b>110</b>, routing common loops <b>202</b>, <b>204</b> attached to the upper ends <b>118</b><i>a</i>, <b>120</b><i>a </i>of the sleeves <b>118</b>, <b>120</b> through openings <b>206</b> formed in the cradle <b>200</b> (a right-end portion of the cradle is a mirror image of the depicted left-end portion of the cradle and thus is not shown for clarity purposes), and extending the lift straps <b>152</b>, <b>154</b> exteriorly of the cradle <b>200</b>. Once exposed through the openings <b>206</b>, the common loops <b>202</b>, <b>204</b> may be attached to corresponding connectors attached to the bag <b>198</b> to secure the bag <b>198</b> to the external frame <b>102</b> (the corresponding bag connectors are not shown). In some implementations, three-bar sliders (such as that shown in <figref idref="DRAWINGS">FIGS. 13A and 13B</figref>) may be attached to the bag <b>198</b> and may be interlocked with the common loops <b>202</b>, <b>204</b> in the manner described above. Although not shown, the bag <b>198</b> also may be attached to lower portions of the external frame <b>102</b> via fabric loops, common loops, three-bar sliders, ladder locks, or other suitable connectors generally known in the art that may be attached to the sleeves <b>118</b>, <b>120</b> (see <figref idref="DRAWINGS">FIG. 4</figref>). The depicted bag <b>198</b> includes a restrictable opening <b>208</b> (such as a drawstring opening), although various types of bags may be attached to the external frame <b>102</b>.

<figref idref="DRAWINGS">FIG. 15</figref> is a rear elevation view of the backpack <b>100</b> of <figref idref="DRAWINGS">FIG. 1</figref> situated on a wearer's back <b>114</b>. With reference to <figref idref="DRAWINGS">FIG. 15</figref>, the external frame <b>102</b> may be contained within the envelope of a wearer's back <b>114</b>. In other words, the upright members <b>106</b>, <b>108</b> (hidden within the sleeves <b>118</b>, <b>120</b>) may be positioned closer to one another than the width of the wearer's back, resulting in weight savings and less bulk based in part on the reduced length of the cross members <b>110</b>, <b>112</b>. The smaller size of the external frame <b>102</b> also reduces the likelihood of a wearer hitting their elbows into the frame <b>102</b> and facilitates movement through tight places when hiking through brush and trees, for example. The upright members <b>106</b>, <b>108</b> may extend above the upper cross member <b>110</b> to facilitate attaching a bag to the external frame <b>102</b>, and the upright members may extend below the lower cross member <b>112</b> to facilitate attaching the waist belt <b>130</b> to the external frame <b>102</b>, thereby stabilizing the backpack <b>100</b>. The waist belt <b>130</b> may wrap around the hip bones, pelvis structure, or both of the wearer to facilitate load transfer from the external frame <b>102</b> to the hips and legs of the wearer.

The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. For instance, although the sleeves are illustrated in association with the upright members, the sleeves may be used in association with the upright members and/or the cross members, which may be constructed of various materials. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.

All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other.