Adjustable Shoulder Strap Attachment Assemblies

CROSS-REFERENCE TO RELATED APPLICATIONS

0001This application is related to U.S. patent application Ser. No. 13/183,767, filed Jul. 15, 2011; U.S. patent application Ser. No. 13/549,289, filed Jul. 13, 2012; and U.S. application Ser. No. 13/856,594, filed Apr. 4, 2013. All of those applications are incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

00021. Field of the Invention

0003In general, the invention relates to backpack frames, and to strap systems for backpack frames.

00042. Description of Related Art

0005Shoulder straps are a key element in distributing the load of a backpack to its wearer. In day packs and smaller backpacks without a frame, the shoulder straps may be sewn directly to the backpack at fixed points, although these arrangements usually include buckles and fittings to change the length of the straps.

0006Backpack frames help to support the load in a backpack and to distribute that load more evenly to the wear's body. Many frames include mechanisms by which shoulder straps can be attached at different heights and positions, in order to accommodate wearers of different builds. In a typical mechanism, a clip is attached to each end of each strap, and the frame provides multiple points to which each clip may be attached.

0007A more continuously adjustable mechanism for attaching straps would be a help in allowing users of different body sizes to comfortably use a backpack and backpack frame.

SUMMARY OF THE INVENTION

0008One aspect of the invention relates to an adjustable strap and frame combination for a backpack. The backpack frame has left and right generally vertically-extending tracks spaced from one another. An expanse of one part of hook-and-loop fastener is provided proximate to the tracks. Left and right straps attach to the backpack frame. Each of the straps includes a cam-fastener and complementary hook-and-loop fastener. The cam-fastener has a projecting portion with at least one dimension greater than a width of one of the tracks, such that the cam-fastener can be pivoted into position to secure the cam-fastener and its connected strap slideably in one of the tracks. The complementary hook-and-loop fastener of the straps is positioned to engage the hook-and-loop fastener of the backpack frame to fix the vertical position of the straps. In some embodiments, the straps include lower portions that connect with a waist belt. The waist belt is adapted to engage lower portions of the backpack frame.

0009In embodiments according to this aspect of the invention, the cam-fastener typically includes a base and a post or neck connected between the base and the projecting portion. The projecting portion may, for example, be a bar with a length greater than a width of one of the tracks.

0010Another aspect of the invention relates to a method of adjustably securing backpack straps to a frame. The method comprises engaging a cam-fastener connected to a strap in a generally vertically-extending track or slot of a backpack frame. The method also comprises sliding the engaged cam-fastener along the track so that the strap is in a desired vertical position, and securing the strap in the frame using hook-and-loop fastener.

0011These and other aspects, features, and advantages of the invention will be set forth below in more detail.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The invention will be described with respect to the following drawing figures, in which like numerals represent like elements throughout the figures, and in which:

<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of a backpack frame with waist belt and left and right strap assemblies;

<figref idref="DRAWINGS">FIG. 2</figref> is an elevational view of the backpack frame in isolation, illustrating the side of the frame that faces the strap assemblies;

<figref idref="DRAWINGS">FIG. 3</figref> is an exploded perspective view of the backpack and frame assembly of <figref idref="DRAWINGS">FIG. 1</figref>;

<figref idref="DRAWINGS">FIGS. 4 and 5</figref> are respective sequential elevational views of the frame, illustrating the attachment of one of the strap assemblies;

<figref idref="DRAWINGS">FIG. 6</figref> is a perspective view of the other side of the frame, illustrating the attachment of one of the strap assemblies; and

<figref idref="DRAWINGS">FIG. 7</figref> is a perspective view of the frame, illustrating various vertical positions in which a strap assembly may be placed in connection with the frame.

DETAILED DESCRIPTION

0019<figref idref="DRAWINGS">FIG. 1</figref> is a perspective view of a backpack frame, generally indicated at <b>10</b>, with two shoulder straps <b>12</b>, <b>14</b> and a waist belt <b>16</b> installed, and <figref idref="DRAWINGS">FIG. 2</figref> is an elevational view of the backpack frame <b>10</b> in isolation. The backpack frame <b>10</b> illustrated in these figures and others is one of the frames described in U.S. Patent Application Publication No. 2013/0221051, the entire contents of which are incorporated by reference in their entirety. This frame <b>10</b> is a unitary, resin-impregnated structure made of carbon fiber, although the general construction of the frame is not critical in all embodiments of the invention, so long as the frame in question has the basic features described here.

0020Relevant to the process of attaching and adjusting the shoulder straps <b>12</b>, <b>14</b>, the frame <b>10</b> has two generally vertical tracks <b>18</b>, <b>20</b> that are sloped slightly inwardly as they extend downwardly. The tracks <b>18</b>, <b>20</b> are fully open and go through the thickness of the frame <b>10</b>. These tracks <b>18</b>, <b>20</b> provide adjustable points of connection to the frame <b>10</b> for the two shoulder straps <b>12</b>, <b>14</b>, as shown in <figref idref="DRAWINGS">FIG. 1</figref>.

0021As shown in <figref idref="DRAWINGS">FIG. 1</figref> and in the exploded perspective view of <figref idref="DRAWINGS">FIG. 3</figref>, each shoulder strap <b>12</b>, <b>14</b> has a cam-fastener <b>22</b> sewn into it. The top of the cam-fastener <b>22</b> is a generally rectangular bar <b>24</b> that, when installed in each strap <b>12</b>, <b>14</b> extends parallel to the width of the strap <b>12</b>, <b>14</b>. The bar <b>24</b> is also longer than the width of the tracks <b>18</b>, <b>20</b>. The rectangular bar <b>24</b> is connected at its center to a post or neck <b>26</b>, which is, in turn, connected to a base <b>28</b>. The base <b>28</b> of the cam-fastener <b>22</b> is at least about as wide as the bar <b>24</b> itself, and in the illustrated embodiment, is a round disc. In general, the cam-fastener <b>22</b> should be made of a lightweight but rigid material, such as ABS plastic [CORRECT?], such that it can sustain the loads carried by the backpack. In other embodiments, the projecting portion of the cam-fastener <b>22</b> need not be a bar <b>24</b>; rather, any non-uniform shape with at least one dimension wider than the width of the tracks <b>18</b>, <b>20</b>. The size and area of the base <b>28</b> and rectangular bar <b>24</b> are sufficient to distribute the load somewhat so as to avoid causing failure of the stitching or other materials in the straps <b>12</b>, <b>14</b> or a failure of the area around the tracks <b>18</b>, <b>20</b>. Typically, the base <b>28</b> is sewn or otherwise fixed into its strap <b>12</b>, <b>14</b>, for example, with adhesives.

0022The process of connecting the straps <b>12</b>, <b>14</b> to the frame <b>10</b> is illustrated in the sequential elevational views of <figref idref="DRAWINGS">FIGS. 4-5</figref>. To connect one of the straps <b>12</b>, <b>14</b> to the frame <b>10</b>, the user places the strap generally perpendicular to its use position, so that the length of the rectangular bar <b>24</b> is parallel with the track <b>18</b>, <b>20</b>, and inserts the bar <b>24</b> through the track <b>18</b>, <b>20</b> before rotating the strap <b>12</b>, <b>14</b> upright into its use position, as illustrated in <figref idref="DRAWINGS">FIG. 5</figref>. In the use position illustrated in <figref idref="DRAWINGS">FIG. 1</figref>, the rectangular bar <b>24</b> is perpendicular to the track <b>18</b>, <b>20</b> so that it cannot pull out of the track <b>18</b>, <b>20</b>.

0023<figref idref="DRAWINGS">FIG. 6</figref> is a perspective view of the frame <b>10</b> and one strap <b>14</b>, illustrating the opposite side of the frame <b>10</b>. The cam-fastener <b>22</b> provides a sliding connection between the strap <b>12</b>, <b>14</b> and the frame <b>10</b> and prevents pull out in the normal direction, i.e., the direction perpendicular to the frame. In order to keep the straps <b>12</b>, <b>14</b> in a particular vertical position along the tracks <b>18</b>, <b>20</b>, the frame <b>10</b> and straps <b>12</b>, <b>14</b> use complementary patches of hook-and-loop fastener. More specifically, each strap <b>12</b>, <b>14</b> has a patch <b>30</b> of hook-and-loop fastener below the cam-fastener <b>22</b>. A complementary expanse <b>32</b> of hook-and-loop fastener is provided in the center of the frame <b>10</b>, below the tracks <b>18</b>, <b>20</b> on the side of the frame <b>10</b> that faces the straps <b>12</b>, <b>14</b>. The present inventors have found that when fully engaged, hook-and-loop fastener has sufficient strength in shear to fix the position of the straps <b>12</b>, <b>14</b> vertically. Moreover, by providing a relatively long swath of hook-and-loop fastener, the user can adjust the vertical position of the straps <b>12</b>, <b>14</b> continuously, with each of the straps <b>12</b>, <b>14</b> in contact with a portion of the hook-and-loop fastener <b>30</b>, <b>32</b>. Thus, as shown in the perspective view of <figref idref="DRAWINGS">FIG. 7</figref>, a single strap <b>14</b> can assume a variety of positions, labeled in <figref idref="DRAWINGS">FIG. 7</figref> as A, B, and C.

0024As those of skill in the art will note, the attachment mechanism described above attaches the upper padded shoulder and chest portion <b>34</b> of each strap <b>12</b>, <b>14</b> to the frame <b>10</b>. In order to function successfully as a strap, the straps <b>12</b>, <b>14</b> must also be connected or coupled to the frame <b>10</b> at their respective lower edges as well. There are a number of potential ways of doing this. Because the lower portions of the straps <b>12</b>, <b>14</b> are load-bearing but not necessarily body-contacting, they generally do not need to be padded along their entire lengths. For that reason, it is generally sufficient to connect the padded upper portion <b>34</b> of each strap <b>12</b>, <b>14</b> to a piece of webbing to act as a lower portion. The webbing <b>36</b> (best seen in <figref idref="DRAWINGS">FIG. 1</figref>) may be, for example, 1 inch webbing. This connection may be by means of a buckle <b>38</b> sewn to the bottom of the upper portion <b>34</b> of each strap

0025If no waist belt <b>16</b> is provided, the webbing <b>36</b> that serves as the lower portion of the strap <b>12</b>, <b>14</b> may simply terminate by attaching to one of a number of small slots <b>40</b> that are provided in the frame <b>10</b>, or to slots that are specifically provided for that purpose. However, in the illustrated embodiment, the webbing <b>36</b> that serves as the lower portion of the straps <b>12</b>, <b>14</b> attaches and is sewn into the waist belt <b>16</b>. As shown in the exploded view of <figref idref="DRAWINGS">FIG. 3</figref>, the waist belt <b>16</b> has a large pocket <b>42</b>. The frame <b>10</b> of the illustrated embodiment terminates in a lower, rounded, generally U-shaped tongue <b>44</b>, and the tongue <b>44</b> slips into the pocket <b>42</b>. The buckle <b>38</b> can be used to lengthen or shorten the effective length of the webbing <b>36</b> to an appropriate length based on the selected vertical position of the upper portion <b>34</b> of the straps <b>12</b>, <b>14</b>, and any excess length can be tied off. Generally, the webbing <b>36</b> has a length in excess of the minimum required, to provide enough length to go through the buckle <b>38</b> and allow for adjustment.

0026While the invention has been described with respect to certain embodiments, the embodiments are intended to be exemplary, rather than limiting. Modifications and changes may be made within the scope of the invention, which is defined by the appended claims.