referring now to the drawings , and first to fig1 , shown generally at 10 is a backpack constructed in accordance with the invention summarized above . the backpack has a forked frame , indicated generally at 12 . the frame has two curved flat members 14 , 16 that are connected together by a handle portion 17 . referring now to fig7 , which is a back view of the frame 10 disconnected from the pack or packsack 40 , the lower portions of the flat members 14 , 16 flare outwardly as indicated at 18 , 20 , respectively . as is best seen in fig2 , the lower - most region of the outwardly flaring parts or frame regions 18 , 20 are lumbar - supporting areas or portions , indicated at 22 , 24 , respectively . attached to these areas are two lumbar pads 26 , 28 . similarly , a scapular pad 30 is connected to the flat members 14 , 16 near the handle portion 18 . the connection of the pads 26 , 28 , 30 to the frame 12 can be done in different ways . in the embodiment illustrated here , the connection is made by the pin and bolt arrangements 32 , 34 for the lumbar pads and a pin and flange arrangement 36 , 38 for the scapular pad 30 . the frame 12 is connected to the pack or packsack 40 by a series of pins or rivets that are located throughout various openings 42 in the frame 12 . like most conventional backpacks , the backpack 10 has a pair of shoulder straps 44 , 46 and waist belt 48 . in this particular instance , however , each shoulder strap 44 , 46 has an elastic or elasticized section 50 , 52 that stretches relative to the material that is used to make up other parts of each shoulder strap . also , attached to each shoulder strap is a separate , substantially non - elastic strap 54 , 56 . these separate nonelastic straps 54 , 56 have a length that is greater than the length of the elastic sections 50 , 52 of the shoulder straps when they are not stretched , which is the case when the backpack is not worn , as reflected in fig1 and 8 . the opposite ends 58 , 60 of each non - elastic strap are connected to each shoulder strap outside and on opposite sides of each elastic section . fig8 is the best illustration of this arrangement . however , when the backpack 10 is placed on a wearer &# 39 ; s back , the weight in the pack 40 puts the shoulder straps 44 , 46 in tension and stretches the elastic sections 50 , 52 until they stretch to the point where non - elastic straps 54 , 56 take up the tension and prevent further stretching . the materials used to make the elasticized sections 50 , 52 and non - elastic straps 54 , 56 are conventional elastic and nonelastic materials . the backpack frame 12 can be made from different materials , so long as they provide the structural shape described above . however , carbon fiber is the preferred material because of the way it can be molded to make a single integrated frame ( as shown at 12 in fig2 , for example ) and because of its attractive appearance . it is believed that a carbon fiber frame of the type described above is unique in the construction of backpacks or backpack frames . the handle portion 17 of the frame 12 both connects and allows the flat members 14 , 16 to torsionally flex relative to each other — which serves to distribute weight as the wearer walks or engages in other physical activities . except for the torsional flex between members 14 , 16 , the frame is otherwise relatively rigid , with the understanding that the thin thickness coupled with the flat - sided construction of members 14 , 16 does allow them to bend elastically forward and backward along with the torsional movement that one might have relative to the other . dimensionally , in the backpack 10 illustrated here , the length of the curved flat members 14 , 16 from handle portion 17 to scapular regions 22 , 24 is approximately 18 inches . the width of the flat members 14 , 16 near the scapular pad 30 is approximately 2 . 25 inches . they are about 0 . 125 inches thick . it is to be understood that these dimensions are examples only and will vary for different kinds of backpacks . the backpack 10 illustrated here is a size that is typically worn by students , although it could be used for day hikes as well . it may be possible to enlarge the dimensions of the frame for use in a backpack of the type used for overnight hiking or expeditions , although that has not been tried in a prototype , as of yet . while openings 42 are provided in the frame 18 for using pins or rivets to connect the frame to the packsack 40 , the mode of connection can be done in different ways . the frame can be permanently attached to the pack 40 or removable attachments ( not shown ) would provide a means for using the same frame for other types of packs or bag arrangements connected to the frame . as described above , the frame &# 39 ; s handle portion 17 extends above the pack 40 so that it is easy to grip as an integrated part of the frame . it is curved aft , as is best seen at 62 in fig6 , for the purpose of making it easier to grip and / or carry the pack 10 by hand like a suitcase . the lumbar and scapular pads 26 , 28 , 30 can also be connected to the frame in different ways and they can be adjusted to alter the way weight is distributed and / or to improve comfort . the scapular pad 30 in particular can be adjusted in height because the frame 12 has a plurality of pin openings 64 ( see fig2 ) that allow the pad 30 to be moved upwardly or downwardly relative to the frame . this adjustment is made depending on the height of the wearer . while the wearer is not illustrated in the drawings , it is easy to see that the curvature of the frame &# 39 ; s flat members 14 , 16 allow the frame to follow the shape of the wearer &# 39 ; s back so that the frame causes the pack 40 to conform to and press against the back . in this respect , the frame pulls the inner surface 66 of the pack 40 against the wearer &# 39 ; s back in a comfortable fashion . the thin thickness of the frame 12 allows it to be integrated with the inner surface 66 of the pack . while it is described and illustrated here as an “ external ” frame , its thin construction integrates it flatly with the pack walls so that the frame 12 and the material making up the inner surface 66 present , together , a fairly uniform surface that presses against the wearer &# 39 ; s back . it may be possible to use the same frame arrangement as an “ internal ” frame as well , although that embodiment has not yet been created in prototype form . the foregoing description is not to be read in a limiting sense . what is considered to be the spirit and scope of the invention is defined in the patent claim or claims that follow , the interpretation of which is to be made in accordance with established doctrines of claim interpretation .
a backpack having a forked frame with curved flat members that are shaped to conform to the curvature of a wearer &# 39 ; s back . the flat members are connected together torsionally by a handle portion that allows each flat member to shift relative to the other to accommodate weight shifts in the backpack load . the forked frame is a single - piece structure that is preferably made of carbon fiber . although the frame is external relative to the pack , the flat construction of the frame allows it to mate with the pack in a way such that the frame is integrated with the inner sidewall of the pack .