Backpack having framesheet assembly

CROSS-REFERENCE TO RELATED APPLICATION

0001This application claims the benefit of U.S. Provisional Application No. 60/494,423, filed Aug. 12, 2003.

BACKGROUND OF THE INVENTION

0002The present invention relates generally to backpacks and, more particularly, to a backpack having a framesheet.

0003Backpacks having a frame support have long been used for carrying heavy, bulky loads. In the past, backpacks were commonly configured to have an external frame that supported a sack. The external frame typically included interconnected metal bars, forming a relatively rigid structure. Shoulder straps and often a hip belt were connected to the frame to distribute the load relatively evenly onto the user. Sacks, typically of nylon or canvas, were secured generally within the confines of the frame and, as such, the sack was relatively spaced apart from the back of the user. Such backpacks could support relatively heavy loads. However, due in part to frame rigidity and load positioning, such backpacks could be relatively awkward, particularly in technically challenging terrain, such as, steep inclines and uneven hiking paths. As a hiker traversed tough terrain, the load tended to shift, which, combined with the spaced location of the load, would to challenge the hiker's balance. Moreover, such metal-frame backpacks are impractical for use in extreme sports.

0004More recent backpacks have incorporated internal frames, which typically include aluminum stays, disposed within pockets of the sack of the backpack. As such, the backpack can be positioned more closely to the back of the user, in an effort to improve overall balance. It also is desirable to have the load of the backpack to move smoothly along with the user. As the user moves, the hips and shoulders tend to rotate relative to one another, inducing a torsional force onto the backpack. Such internal frame backpacks tend to rely upon the sack to provide sufficient torsional flexibility to accommodate such twisting, typically at the expense of other performance factors such as load support.

0005Although such internal-frame backpacks are generally effective, certain shortfalls exist. For example, as the backpack pressed against the back of the user, ventilation can be an issue. Inadequate ventilation between the pack and the user can cause excess heating, resulting in great discomfort. Also, when the sack is substantially loaded, it tends to bulge outwardly, commonly referred to as “barreling,” which too can result in discomfort. Efforts to combat such factors tend to inhibit torsional flexibility, as well as increase costs.

0006It should, therefore, be appreciated that there exists a need for a backpack that provides superior torsional flexibility and load support, while facilitating ventilation between the user and the pack. The present invention fulfills this need and others.

SUMMARY OF THE INVENTION

0007Briefly, and in general terms, the invention resides in a backpack incorporating a framesheet and having superior torsional flexibility and load support. The backpack includes a sack configured to be disposed on a user's back and having a first side adjacent to the user's back, when worn. The framesheet is attached to the first side of the sack, generally with the spine of the user, to include an upper region of the framesheet generally disposed adjacent to the scapulas of the user. The framesheet has a surface contour that facilitates load support and inhibits barreling.

0008More specifically, in a presently preferred embodiment, by way of example and not limitation, the framesheet preferably has a curved side profile generally conforming to the back of a user. In this exemplary embodiment, the framesheet has its narrowest width, as measured laterally across, in an intermediate region and can further include a channel extending longitudinally along the framesheet. Optionally, a stay can also be provided to the backside of the framesheet, preferably along the centerline thereof.

0009In a detailed aspect of a preferred embodiment, the framesheet includes a channel extending down the centerline of the framesheet substantially at least in the upper region thereof. The framesheet preferably is formed of plastic such as thermo-formed of high-density polyethylene (HDPE) material and may further include a plurality of contoured sections generally located in the upper region thereof to further enhance rigidity and inhibit barreling.

0010In another detailed aspect of a preferred embodiment, the sack includes scapula pads and a lumbar pad spaced about the first side of the sack thereby defining a ventilation path having an elongated central portion extending longitudinally along the first side and two side portions extending laterally from a bottom end of the central portion. The pads can be hinged along respective outer edges to the first side of the sack and positioned to at least partially cover the framesheet. A substantial portion of the channel, nonetheless, can remain uncovered to facilitate ventilation. The framesheet can be secured to the sack in various manners. For example, the sack can define a pocket for receiving the framesheet such that it is fully concealed.

0011In yet another detailed aspect of a preferred embodiment, pair of attachments are pivotally mounted to the upper portion of the framesheet and are aligned to receive upper portions of the shoulder straps. Each attachment defines a plurality of slots for attaching the shoulder straps to further facilitate a proper fitting for the user.

0012In yet another detailed aspect of a preferred embodiment the surface contour of the framesheet defines a channel extending along the longitudinal axis of the framesheet at least in the upper region thereof and can further define a plurality of contoured sections in the upper portion of the framesheet, each contoured section delineated by curved side walls.

0013For purposes of summarizing the invention and the advantages achieved over the prior art, certain advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

0014All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

0015Embodiments of the present invention will now be described, by way of example only, with reference to the following drawings in which:

0016<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of a partially assembled backpack in accordance with the invention, depicting a framesheet positioned in a recess defined in a first side of sack, with shoulder straps excluded for visibility.

0017<figref idref="DRAWINGS">FIG. 2</figref> is a perspective view of the backpack of <figref idref="DRAWINGS">FIG. 1</figref>.

0018<figref idref="DRAWINGS">FIG. 3</figref> is an exploded perspective view of the framesheet of <figref idref="DRAWINGS">FIG. 1</figref>.

0019<figref idref="DRAWINGS">FIG. 4</figref> is a plan view of the framesheet of <figref idref="DRAWINGS">FIG. 1</figref>.

0020<figref idref="DRAWINGS">FIG. 5</figref> is a side view of the framesheet of <figref idref="DRAWINGS">FIG. 1</figref>.

0021<figref idref="DRAWINGS">FIG. 6</figref> is a cross-sectional view of the framesheet of <figref idref="DRAWINGS">FIG. 1</figref>, taken along line B-B of <figref idref="DRAWINGS">FIG. 4</figref>.

0022<figref idref="DRAWINGS">FIG. 7</figref> is a perspective view of another embodiment of a backpack in accordance with the invention, depicting a framesheet (in phantom) positioned in a pocket defined on a first side of a sack, with shoulder straps excluded for visibility.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

0023With reference to the illustrative drawings, and particularly to <figref idref="DRAWINGS">FIG. 1</figref>, there is shown a backpack <b>10</b> having a framesheet <b>12</b> and a sack <b>14</b> for carrying a load. The framesheet is received within a recess defined on a backside <b>16</b> of the sack. The sack includes top and bottoms sleeves <b>18</b>, <b>20</b> into which top and bottom edges of the framesheet are received, respectively. The sack further includes scapula pads <b>22</b> and a lumbar pad <b>24</b> that at least partially cover the framesheet, once fully assembled. When worn, the backpack snuggly conforms to the back of the user and, yet provides ample ventilation, as depicted in <figref idref="DRAWINGS">FIG. 2</figref> by arrows A. As discussed in detail below, the backpack also provides superior torsional flexibility and load support.

0024With reference now to <figref idref="DRAWINGS">FIGS. 3-5</figref>, the framesheet <b>12</b> has an upper region <b>26</b> generally disposed adjacent to the scapulas of the user, an intermediate region <b>28</b>, and a tail region <b>30</b>. In this embodiment, the framesheet generally has an hourglass profile, i.e., wherein the intermediate region is comparatively narrow. The upper region includes the greatest width (W_u) of the framesheet, about 25 cm. The intermediate region generally corresponds to a mid-region of the user's back between the scapulas and the hip bones and includes the narrowest width (W_i) of the framesheet, about 11 cm. The tail region is positioned below the intermediate region, flaring to a width (W_t) of about 17 cm. Accordingly, the framesheet provides rigid load support while facilitating torsional flexibility, particularly, in the intermediate region thereof. Thus, the backpack <b>10</b> accommodates rotation of the user's hips and shoulders relative to one another, without undue shifting of the load.

0025The upper portion <b>26</b> of the framesheet <b>12</b> has a variable surface contour configured to facilitate rigidity to the upper portion. In the exemplary embodiment, the upper portion includes four contoured sections <b>32</b>. Each section includes a floor <b>35</b> and curved side walls <b>37</b>. The sections are recessed, as viewed from a front side <b>39</b> of the framesheet. Two sections are disposed on each side of the centerline of the framesheet. On each side of the centerline, corresponding side walls of the sections form a downwardly angled protrusion <b>41</b>. Beneficially, the framesheet is sufficiently rigid, particularly, in the upper portion, to inhibit barreling of the backpack towards the user's back, even when fully loaded. In other embodiments, the surface contour of the framesheet, including the upper portion can be formed in various configurations to facilitate backpack performance. The upper portion further defines an arcuate cutout <b>33</b> to facilitate free movement of the user's head, which can be varied or excluded in other embodiments, as requirements dictate.

0026In this embodiment, a stay <b>36</b> is attached to the backside <b>38</b> of the framesheet generally along a centerline thereof, aiding in load support without detriment to torsion flexibility. The stay includes a reinforced upper end <b>42</b> attached to the framesheet by rivets <b>44</b> and a lower end attached to the framesheet by rivet <b>46</b>. Both the framesheet and the stay are independently provided with a longitudinally curved shape (<figref idref="DRAWINGS">FIG. 5</figref>). Depending upon particular applications, stays of various lengths can be used or, alternatively, can be excluded entirely. For example, the stay can extend up to the connection points of the attachments <b>48</b> (<figref idref="DRAWINGS">FIG. 3</figref>). Also, in this embodiment, an aluminum stay is used; however, stays formed of other materials providing sufficient rigidity can be used, e.g., plastic, carbon fiber, and metals.

0027With reference to <figref idref="DRAWINGS">FIGS. 4 and 6</figref>, an I-beam molding, i.e., channel <b>34</b>, is defined along the centerline of the framesheet. As seen in <figref idref="DRAWINGS">FIG. 6</figref>, the channel has inwardly sloping walls and a maximum depth (D) of about 10 mm. The channel facilitates superior rigidity, particularly in light of forces exerted by the load, while enhancing ventilation. In the exemplary embodiment, the channel extends the entire length of the framesheet. Channels of varied length can also be used. In the exemplary embodiment, as best seen in <figref idref="DRAWINGS">FIG. 6</figref>, the walls of the channel define angular corners <b>49</b>.

0028In the exemplary embodiment, the framesheet <b>12</b> is thermo-formed (e.g., vacuum-formed) of high-density polyethylene (HDPE) material as a unitary piece having a generally constant thickness of about 1 mm. Nonetheless, other embodiments are contemplated of various other materials and/or variable thickness to facilitate performance of the backpack, e.g., torsional flexibility, rigidity, countering barreling, and overall weight considerations. For example, the framesheet can be provided with varied thickness in particular portions, such as, along the centerline or in the upper region to enhance rigidity in those areas. Compression molding and injection molding can also be used, as appropriate. Acrylonitile butadiene styrene (ABS) plastic has also been used in exemplary embodiments. Depending upon requirements of a particular embodiment, the framesheet can be formed of various other materials having sufficient structural strength and flexibility, as needed. For example, other suitable materials include: metals; composites, e.g., glass-fiber composites; and plastics, e.g., thermoplastics and/or thermosets singly or in combination.

0029With reference to <figref idref="DRAWINGS">FIG. 3</figref>, a pair of attachments <b>48</b> are pivotally mounted to the framesheet <b>12</b> to which shoulder straps (not shown) are attached. Each attachment defines two slots <b>50</b>, either of which can be used to attach the shoulder straps. Having multiple slots facilitates a proper fit for users of various proportions, including torso length. Also, the attachments pivot to align the shoulder straps to accommodate the user's proportions, such as, shoulder slope and neck width. In this embodiment, the attachments also are formed HDPE material. As best seen in <figref idref="DRAWINGS">FIG. 2</figref>, once assembled, the attachments are at least partially hidden by the scapula pads <b>22</b>. Thus, when worn, the attachments tend to press the scapula pads snuggly against the shoulders of the user.

0030With reference again to <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, the backpack is configured for easy assembly. To assemble, the framesheet is inserted into the top and bottoms sleeves <b>18</b>, <b>20</b> of the sack <b>14</b>. The sleeves are formed of strong material, such as, Hypalon®, a polyethylene material available from DuPont Dow Elastomers L.L.C. Once in place, the scapula pads are attached. The scapula pads <b>22</b> are hinged along respective outer edges <b>52</b> to the sack and further include straps <b>54</b> of having hook-and-loop fabric. The straps are positioned along inner edges <b>56</b> of the scapula pads, aligned to extend through slits <b>58</b> defined in the framesheet <b>12</b> and the sack, respectively. The straps are threaded through the slits and attached to one another to hold the scapula pads snug against the framesheet. In the exemplary embodiment, the scapula pads do not cover the channel <b>34</b> of the framesheet, thereby facilitating ventilation.

0031The lumbar pad <b>24</b> is hinged along its lower edge to the sack <b>14</b> and includes straps <b>62</b>. The lumbar straps are aligned to extend through slits <b>64</b> defined in the framesheet <b>12</b> and the sack, respectively. The backpack may further include a waist belt (not shown) deposed between the framesheet and the lumbar pad. The waist belt can be attached to either or both the framesheet and the sack, by means known in the art, e.g., rivets, snaps, straps having hook-and-loop fabric, and the like.

0032With reference now to <figref idref="DRAWINGS">FIG. 7</figref>, another exemplary embodiment of a backpack <b>80</b> is shown. In this embodiment, the backpack includes a sack <b>82</b> that defines a pocket <b>84</b> for receiving a framesheet <b>86</b>. The framesheet is similarly configured and aligned with respect to the user, as discussed above. The framesheet resides entirely within the pocket and can be sewn or otherwise secured in place. The pocket is defined on a first side <b>88</b> of the sack. Scapula pads and a lumbar pad similarly shaped to those discussed above can be provided for comfort and to facilitate ventilation. Breathable material such as mesh can be provided on the front side of the sack to further facilitate ventilation. For example, mesh material can extend between the pads, allowing the channel of the framesheet to aid in ventilation.

0033It should be appreciated from the foregoing the present invention provides a backpack a backpack incorporating a framesheet and having superior torsional flexibility and load support. The backpack includes a sack configured to be disposed on a user's back and having a first side adjacent to the user's back, when worn. The framesheet is attached to the first side of the sack, generally with the spine of the user. A surface contour is provided to the framesheet that facilitates load support and inhibits barreling. The framesheet has a first width in the upper region and a second width less than the first width, the second width residing in the intermediate between the scapulas and the hip bones of the user. Optionally, a stay can also be provided to the backside of the framesheet, preferably along the centerline thereof.

0034Although the invention has been disclosed in detail with reference only to the preferred embodiments, those skilled in the art will appreciate that various other embodiments can be provided without departing from the scope of the invention. Accordingly, the invention is defined only by the claims set forth below.