Combination backpack frame and cot

A combination backpack and cot characterized by a main frame assembly and a pair of extension frame assemblies slidably coupled to the main frame assembly. When the extension frame assemblies are retracted the device serves as a backpack frame, and when the extension frame assemblies are extended the device serves as a cot. A pair of webs are used to support the weight of the backpacker when the device is in its cot configuration. A first of the webs is stretched tightly across the main frame assembly and supports most of the weight of the backpacker. A second web extends between the extension frame assemblies to support the extremities of the backpacker. The extension frame assemblies can be locked into a number of intermediate positions between their retracted position and their fully extended position so that the cot can be adjusted in length to fit the backpacker.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to sports equipment, and more particularly 
to multi-purpose backpack frames. 
2. Description of the Prior Art 
Backpacking is a heathful and invigorating sport enjoyed by people all over 
the world. When backpacking, a person hikes into the backcountry while 
carrying all of the supplies and equipment that he or she needs in a 
frame-mounted knapsack. 
Because backpackers usually wish to carry as little weight as possible, the 
bedding materials carried by most backpackers is quite spartan. For 
example, a backpacker may carry only a sleeping bag and a ground cover. 
Backpackers who wish to have greater creature comforts may additionally 
carry a foam pad or an inflatable mattress. 
Most backpackers will agree that sleeping on the ground, even with a foam 
pad or air mattress, is far from the most healthful and restful sleeping 
arrangement. The hard, bumpy, sloped, and irregular ground surfaces upon 
which backpacker must often sleep causes many backpackers to awaken many 
times during the night. The lightweight foam pads which some backpackers 
use are usually too thin to provide a truly comfortable sleeping surface. 
Air mattresses are often comfortable at the time the backpacker retires 
for the evening but are usually flat by the time the weary and sore 
backpacker arises in the morning. 
One solution to this problem is for the backpacker to bring along a folding 
cot. However, for the aforementioned weight consideration reasons, most 
backpackers prefer not to do this. 
A solution to this dilemma has been suggested by a number of inventors who 
propose to form a cot out of an item already being carried by the 
backpacker, namely the backpack frame. For example, in U.S. Pat. No. 
4,056,857 of Quantz a convertible backpack and cot is described which has 
two mutually slidable frame portions held together with a plurality of 
fastening straps. U.S. Pat. No. 3,846,855 of Peterson teaches a 
convertible backpack and cot including a unitary extensible frame having 
telescoping side and end portions. 
A problem with convertible backpack/cots of the prior art is that their 
strength-to-weight ratio tends to be rather low. The lightweight prior art 
backpack/cots tend to be unsteady and unsuited for rugged use. The more 
sturdily constructed prior art backpack/cots tend to be too heavy to be 
practicable for backpacking applications. 
A further problem with backpack/cots of the prior art is that they are not 
adjustable in length. As a consequence, prior art backpack/cots have to be 
designed and built to comfortably support the tallest and heaviest 
conceivable user of the cot, with the result that the backpack/cots are 
heavier and more expensive than they need to be. 
SUMMARY OF THE INVENTION 
An object of this invention is to provide a rugged, sturdy, and lightweight 
convertible backpack/cot. 
An other object of this invention is to provide a convertible backpack/cot 
which, in its cot configuration, is adjustable in length. 
Briefly, the convertible backpack/cot of the present invention includes a 
main frame assembly, and a pair of extension frame assemblies slidably 
engaged with the main frame assembly. When the backpack/cot is in its 
backpack configuration the extension frame assemblies are retracted 
against the end members of the main frame assembly and are held in place 
with lockpins. When the backpack/cot is in its cot configuration the 
extension frames are cantilevered from the main frame assembly and, once 
again, held in position with the lockpins. 
The main frame includes a pair of U shaped end members, and two pair of 
slider tubes coupling the U shaped end members together. The extension 
frames are U shaped and each have their legs engaged with two of the 
slider tubes of the main frame. The lockpins extend through holes provided 
in the main frame to engage holes provided in the legs of the extension 
frames. 
A main frame web is stretched across the main frame to support most of the 
weight of the backpacker reclining on the cot, and an extension frame web 
extends between the two extension frame assemblies to support the head and 
feet of the backpacker. A roller assembly is provided in one or both of 
the extension frame assemblies to tension the extension frame web. 
Preferably, the extension frame web is interwoven through a pair of slots 
provided in the main frame web so that the webs form an integral unit. 
The two extension frame assemblies can be retained in a number of positions 
intermediate to their retracted and extended positions by use of the 
aforementioned lockpins. The roller assembly is used to take up the slack 
in the extension frame web when the extension frame members are in these 
intermediate positions. 
Advantages of this invention include its ability to have its length 
adjusted and in that it has a high strength-to-weight ratio. When the 
extension frame members are in their retracted position they serve as 
reinforcements to the slider tubes of the main frame. When in use as a 
cot, the extension frame members are only extended far enough to 
accommodate the height of the backpacker and thus reduce the pressure 
exerted on their cantilevered juncture with the main frame. Furthermore, 
most of the weight of the backpacker is supported on the main frame web, 
which allows the extension frame members to be relatively lightweight. 
Thus, the combination of the extension frame and main frame construction 
and the use of two, interwoven support webs results in a lightweight yet 
extremely rugged combination backpack/cot. 
These and other objects and advantages of the present invention will no 
doubt become apparent upon a reading of the following descriptions and a 
study of the several figures of the drawing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
Referring to FIG. 1, a convertible backpack/cot 10 in accordance with the 
present invention includes a main frame assembly 12 and a pair of 
extension frame assemblies 14 and 16. As suggested by arrows 18 and 20, 
extension frame assemblies 14 and 16 can slide between the extended 
position shown in the figure, and a retracted position in abutment with 
main frame assembly 12. 
Main frame assembly 12 includes a pair of separated, U shaped end members 
22 and 24 which are preferably made from bent aluminum tubing. The end 
members 22/24, which are substantially identical, each have a pair of 
short, parallel leg portions 26 and 28, and a concave, arcuate connecting 
portion 30. End caps 32 cover the open ends of leg portions 26/28. 
Main frame assembly 12 also includes a pair of connecting assemblies 34 and 
36 which connect end members 22 and 24 together. Further bracing may be 
provided by longitudinal braces 38 and 40, and lateral braces 42 and 44. 
Connecting assemblies 34/36 each include a pair of parallel slider tubes 
46 and 48, and a knapsack connection plate 50. Slider tubes 46/48 and 
connection plate 50 are preferably welded to each other and to the end 
members 22/24. 
A pair of holes 52 are provided in the legs 26/28 of end member 22 in 
alignment with tubes 48 of connecting assemblies 34/36. A similar pair of 
holes 54 (see FIG. 4) are provided in the legs 26/28 of end member 24 in 
alignment with tubes 46 of connecting assemblies 34/36. 
The extension frame assemblies 14/16 are substantially U-shaped and include 
first leg portions 55, second leg portions 57, and connecting portions 59. 
The leg portions 55/57 of extension frame assembly 14 extend through holes 
52 of end member 22 to slidably engage tubes 48 of connecting assemblies 
34/36. Similarly, leg portions 55/57 of extension frame 16 assembly extend 
through holes 52 of end member 24 to slidable engage tubes 46 of 
connecting assemblies 34/36. 
Referring now to FIGS. 2 and 3, backpack/cot 10 further includes a main 
frame web 56 attached to main frame 12, and an extension frame web 58 
extending between extension frames 14 and 16. Main frame web 56 is 
preferably made from a strong, lightweight material such as 1/16 inch 
weave nylon mesh and is provided with 1/2 inch reinforced slots 60 which 
are receptive to the extension frame web 58. Opposing lateral edges of 
main frame web 56 are provided with eyelets 62 through which lacing 64 
(preferably made from a strong, flexible material such as rayon) can be 
laced to properly hold the main frame web 56 in place around connecting 
assemblies 34/36. 
Extension frame web 58 is preferably made from rip-stop nylon and extends 
between connection portion 59 of extension frame 14 and connection portion 
59 of extension frame 16. The extension frame web 58 is interwoven through 
slots 60 of main frame web 56 and is adapted for longitudinal travel 
through the slots. 
Referring now to FIG. 3 and the cross sectional view of FIG. 4, main frame 
web 56 is provided with a plurality of openings 66 near locking pin holes 
68 provided in slider tubes 46 and 48. Locking pins 70 (see FIG. 2) extend 
through locking pin holes 68 to engage one of holes 72 provided in leg 
portions 55 and 57 of extension frame assemblies 14/16. This arrangement 
allows the length of the backpack/cot 10 to be varied. 
Referring now to FIGS. 5 and 6, connection portions 59 of end members 14/16 
preferably include a roller assembly including a roller tube 73 and a pair 
of roller tube locking pins 74. Roller tubes 73 engage lateral holes 76 
through the end portions of leg portions 55/57 of extension frame 
assemblies 14/16. A vertical hole 78 is provided through leg portions 
55/57 to accept a locking pin 74 and split rings 80 hold locking pins 74 
in place. Roller tube 73 is also provided with a crank hole 82 receptive a 
removable crank handle 84. A plurality of end caps 86 are engaged with the 
ends of roller tubes 72. 
In use, the present invention has two operating modes. When used as a 
backpack, extension members 14/16 are retracted so that connecting 
portions 59 abut end members 22/24 and locking in place with locking pins 
70. Roller tubes 73 are rotated with crank handle 84 to take up the slack 
and extension frame with 58 and are then held in place with locking pins 
74. A backpack of conventional design can be attached to knapsack 
attachment plates 50 of connecting assemblies 34/36 within the confines of 
the main frame assembly 12. 
When used as a cot, lock pins 70 and 74 are removed and extension frame 
assemblies 12 and 14 are extended from main frame 12. When the 
backpack/cot 10 is at its desired length, lock pins 70 are reinserted into 
lock pin holes 68 to prevent longitudinal movement of extension frames 
14/16. Crank 84 is then inserted into crank hole 82 of one or the other of 
roller tubes 73 to take up the slack in web 58. Locking pins 74 are used 
to prevent roller tubes 73 from rotating once the proper tension has been 
applied to web 58. 
While this invention has been described in terms of a few preferred 
embodiments, it is contemplated that persons reading the preceding 
descriptions and studying the drawing will realize various alterations, 
permutations and modifications thereof. It is therefore intended that the 
following appended claims be interpreted as including all such 
alterations, permutations and modifications as fall within the true spirit 
and scope of the present invention.