U.S. patent application number 10/605969 was filed with the patent office on 2004-06-10 for external frame backpack.
Invention is credited to Warren, Bruce.
Application Number | 20040108350 10/605969 |
Document ID | / |
Family ID | 32474149 |
Filed Date | 2004-06-10 |
United States Patent
Application |
20040108350 |
Kind Code |
A1 |
Warren, Bruce |
June 10, 2004 |
External Frame Backpack
Abstract
A backpack for a human to carry a load utilizing an external
frame to which is attached a fabric bag comprised of multiple
compartments each of a cylindrical geometry where the compartments
share no common fabric panels. The frame has a bottom shelf that
bears the weight of the bag allowing lighter fabric to be used and
also allows the backpack to stand by itself on the ground. The two
outside vertical tubes of the frame are not parallel, being tapered
inward towards each other at the top and also rising above the
topmost compartment of the bag to provide a hanging fixture for
other hiking gear. A waist belt assembly can incorporate a curved
polymer insert to distribute the majority of the weight of a loaded
pack on the lumbar curve of the spine. The insert is overlaid with
a panel of cushioning material that can be repositioned to form the
base of a camp chair.
Inventors: |
Warren, Bruce; (Lake
Jackson, TX) |
Correspondence
Address: |
BRUCE A. WARREN
2307 WHITETAIL LANE
LAKE JACKSON
TX
77566
US
|
Family ID: |
32474149 |
Appl. No.: |
10/605969 |
Filed: |
November 10, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60319718 |
Nov 22, 2002 |
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Current U.S.
Class: |
224/633 ;
224/637 |
Current CPC
Class: |
A45C 7/0086 20130101;
A45F 2003/127 20130101; A45F 3/08 20130101; A45F 3/047 20130101;
A45F 4/02 20130101 |
Class at
Publication: |
224/633 ;
224/637 |
International
Class: |
A45F 003/04; A45F
003/08; A45F 003/10 |
Claims
1. an external frame backpack for a human to carry a load
comprising: a) an external frame comprised of two vertical elements
and two or more horizontal elements attached between said vertical
elements where the four corners of said frame in the posterior view
forms a trapezoid with the top dimension being visibly shorter than
the bottom dimension; b) a horizontal shelf attached to said
external frame extending more or less perpendicular from the plane
of said frame and located near the lower end of said frame in a
manner that causes said frame to stand up on a surface with no
additional support; c) two shoulder straps with ends attached near
the top and bottom of said frame.
2. A backpack of claim 1 with a bag attached to said external frame
wherein; a) said bag is comprised of two or more compartments
wherein each said compartment includes no panel that is a
structural component of another said compartment; b) said bag is
attached to said vertical elements in a manner that allows said
compartments to independently and freely move up or down said
vertical elements, and each said compartment rests on the said
compartment below and the lowest said compartment rests on said
horizontal shelf.
3. A backpack of claim 1 with a waist belt attached to said
external frame.
4. A backpack of claim 2 with a waist belt attached to said
external frame.
5. A backpack of claim 2 wherein said compartments display a
cylindrical geometry and said compartments can be independently
mounted to and removed from said external frame.
6. A backpack of claim 3 wherein said frame includes two horizontal
elements located near the lower portion of the frame with at least
two additional vertical sub-elements connecting said two horizontal
elements some distance inward from said two vertical elements; and
said waist belt utilizing an outer cover composed of at least
partially a hook-and-loop surface; and a band of hook-and-loop tape
wrapping around said waist belt and said two horizontal elements
providing an inflexible attachment method to said horizontal
elements at a fixed position between said vertical
sub-elements.
7. A backpack of claim 3 wherein one end of said waist belt
provides a loop fixture and the other end of said waist belt
provides a strap that passes through said loop where the loose end
of said strap binds to said waist belt with a hook-and-loop
fastener.
8. A backpack of claim 4 wherein extensions of said vertical
elements rise above the top of the uppermost said horizontal
element and said extensions are free of encumbrance by said bag;
said backpack engaging a frontpack hung by straps around said
extensions where said frontpack also attaches to said waist belt in
a manner such that said waist belt bears a portion of the weight of
said frontpack.
9. A backpack for a human to carry a load comprising: a) an
external frame comprising two vertical elements and two or more
horizontal elements connecting said two vertical elements; b) at
least one special horizontal element displaying a bi-laterally
symmetrical V-shape in the posterior view and connecting said two
vertical elements near the top; c) a waist belt that can be
adjusted in the vertical direction relative to said external frame
such that said special horizontal element is located at a vertical
position that is above the top of said human's shoulders; d) two
shoulder straps wherein the top ends of said straps attach to each
side of said V-shaped horizontal element in a manner that allows
the top of said shoulder strap to slide freely along said V-shaped
element without contacting the top of said human's shoulders.
10. A method of assembling a pack bag comprised of two or more
compartments wherein said compartments include no panel shared as a
structural component with another said compartment; said method
utilizing one or more attachment devices comprised of a tube and a
rod wherein said tube has a "C" cross-section producing a narrow
slot the full length of said tube and said rod has a diameter small
enough that said rod fits loosely coaxially inside said tube, and
said rod has a diameter large enough that said rod will not slip
through said slot in said tube, both said rod and said tube of a
length shorter than the inside length of either said compartment;
wherein a fold of fabric of two adjacent said compartments
envelopes said rod while said tube slips over said fold of fabric
trapping said rod and said fold of fabric in place thus preventing
a radial separation;
Description
BACKGROUND OF INVENTION
[0001] The present invention pertains generally to backpacks used
by backcountry hikers who must carry large amounts of gear. Many
types of backpacks are available on the market to meet this need
and are generally divided into three categories 1) knapsacks 2)
internal frame packs and 3) external frame packs. Hikers strive to
find a pack that can carry the required gear weight with a minimal
amount of pack weight and a maximum amount of personal comfort.
[0002] A backpack is the primary piece of gear needed by a long
distance hiker. Differences in human body sizes and shapes make it
very difficult to create a backpack that fits a wide range of
hikers and delivers a comfortable hiking experience. The first
popular type of backpack was the knapsack, a fabric bag with two
shoulder straps that place the weight of the pack on the hiker's
shoulders. This causes discomfort to most hikers thus limiting the
knapsack to lightweight pack loads. The external frame pack was
developed to improve the knapsack. The knapsack was attached to a
ladder-like frame usually made of wood or aluminum. The frame had
two shoulder straps and a hip belt attached. By tightening the hip
belt the hiker can cause a big portion of the pack weight to be
borne by the pelvic bone structure, relieving the pressure on the
shoulders.
[0003] The external frame pack is widely used today. The drawbacks
of the external frame backpack are the rigid external frame that
can limit the outdoor spaces a hiker can squeeze through and the
stiffness of the frame that can restrict some bending movements of
the hiker. Many hikers also find the hip belt of the external frame
pack can cause pain in the hip bones. Another drawback is many
external frame backpacks are heavy as the result of a multiplicity
of frame tubes, adjustment mechanisms, and extra padding to enable
a comfortable fit on a range of different body sizes and
shapes.
[0004] The internal frame pack is the most recent innovation in
backpack design. Rather than taking a knapsack and attaching it to
an external frame, an internal frame is attached to the material of
a modified knapsack. No frame is visible from the outside. This
allowed the pack designer to mount bendable stays into the pack bag
that can be curved to fit the entire back of each individual hiker.
This produced an increase in comfort for many hikers. The internal
frame pack is currently the most popular offering in the
marketplace.
[0005] The internal frame pack has several drawbacks that include a
relatively heavy weight, poor ventilation of the hiker's back, and
difficulty packing and unpacking. The internal frame backpack is
relatively heavy due to the use of many layers of fabric and
padding to contain the internal frame and to pad the hip belt and
shoulder belts. Typically such a pack will weigh seven pounds or
more. The pack bag is constructed from heavy fabric, typically 400
and 1000 denier nylon, in order to give it shape and to transfer
loads from the rear of the pack to the internal frame at the front.
The internal frame transfers most of this weight down to the hip
belt. The padded front face of the pack is held tightly against
almost the entire back of the hiker. This padding produces excess
sweating and discomfort from constantly wet skin. The pack bag is
difficult to pack and unpack because it is effectively a single
tall narrow volume. Items at the bottom cannot be retrieved unless
all items above are removed. Some internal frame backpack designs
include side or rear pouches to partially alleviate this problem,
but they stick out and make trail navigation more difficult. The
pack will usually have straps to compress the bag to compact
internal gear and keep it from shifting or moving around with each
hiking step. These straps add weight and complexity and reduce
reliability, since they are one more thing that will break.
[0006] While the backpacks cited in the following references each
offer a novel improvement, these references also reveal the
continuing disagreements in the backpacking community in the most
fundamental areas of pack design, such as which part of the human
body is best at bearing the weight of a backpack, or how to best
position a waist belt. As a result, proffered improvements in
design rarely result in any improvement in comfort or usability for
the hiker in the field and very rarely show up in retail products.
If offered in commercially available backpacks, the novel
improvement is usually overwhelmed or cancelled out by a
multiplicity of remaining defects. The backpack of the present
invention offers a combination of novel improvements including a
tapered external frame with strong but ultralight joints, a bag
with individual compartments that share no common fabric panels, a
waist belt geometry that directs the pack weight into the lumbar
region of the body, and a lumbar pad that swivels to become a seat.
However, in addition to its novel improvements, the present
invention integrates a multiplicity of designs from the established
art to work together as a functional system to enable real benefits
to the hiker from the novel improvements of the present
invention.
[0007] Weight Transfer Devices--For instance, 4,369,903 by Wilkes
offers a means of adding tubing to the external frame to transfer
weight to a hip belt. Gleason in 6,179,188; 5,904,282 and 5,762,251
offers a similar technology. Earlier, Owens utilized tubes to the
hip belt in 3,581,961 and so did Wilkes in 4,369,903. All of these
increase the weight and complexity of the backpack with little or
no improvement in comfort since the amount of weight on the hips is
determined by the adjustment of the shoulder straps. In addition,
static analysis of force vectors reveals that adding tubes only
adds weight; a new tube cannot cause a weight transfer. All the
weight of a backpack must be born by compressing the human body at
one or more points. If the hiker is standing upright, only the
torso or shoulders can be compressed to bear weight. At best,
adding tubes can shift this compression from the stomach around
toward the hip region, or from the shoulders to the lumbar region.
But the total bodily compression (another measure of discomfort)
remains the same for any pack design that has its center of gravity
the same distance behind the hiker's spinal column
[0008] Multiple Compartments--The Modular Backpack by Von Neuman
(6,189,750) offers multiple compartments, but these multiple
compartments are not attached to an external frame, thus producing
a backpack that can carry little weight without discomfort. Mack in
3,219,243 shows an external frame with framing elements for
shelves. This adds weight. Deutsch in 5,628,443 offers slip on/off
compartments that attach to a traditional rectangular central bag.
This adds excessive weight since such small volume compartments and
connectors have a high weight to volume ratio. Bentsen in 6,161,739
utilizes fabric shelves inside a rectangular bag with a complex and
heavy internal metal frame. Patent application 2001/0017307
describes a backpack with an internal tubular frame that can
collapse. The frame supports a bag with compartments. The
compartments share a fabric shelf that allows gear to protrude
between compartments and allows leaks to pass into compartments
below. In contrast, the present invention offers compartments that
are individual cylinders that share no common fabric panels. In the
late 1960's the Gerry Company sold an external frame backpack with
a fabric bag divided into four stitched horizontal sections
accessible with zippers with shared fabric dividers. This pack
utilized a thin mesh band at lumbar level and a two piece hip belt
attached to the side tubes of the frame. This was very light, but
created pressure points on the hip bones that limited the weight
that could be carried comfortably. The website
www.thewildernesswanderer.com sells a modular backpack called the
Wilderness Wanderer that has an external metal frame that has a
rigid bottom loop of tubing, or shelf. The aluminum frame has a
traditional ladder geometry with a pair of parallel vertical tubes
with multiple horizontal cross tubes where the present invention
has a frame that is narrower at the top to better conform to the
human body shape and to force weight to be carried down lower. The
Wilderness Wanderer frame can have a series of different size bags
attached to it. These bags are pinned in fixed positions to the
frame. The weight of the gear is supported by the pins since the
bags cannot slide down on the frame as is possible on the present
invention. The bottom shelf does not support the weight of the gear
inside the bags, serving only to help keep the pack upright when
set on the ground. The backpack is very heavy due to the thick
fabric, a rectangular bag mounted up high, and a large metal frame.
The Wilderness Wanderer pack will tip over on uneven or rocky
ground due to the high center of gravity of a fully loaded pack.
The present invention has a frame that is narrower in width at the
top with typically four cylinders to store gear where the top
cylinder will hold 500 cubic inches, and the bottom cylinder will
hold 1600 cubic inches. This means the hiker will typically have
three times as much weight in the bottom of the pack as in the top.
This significantly lowers the center of gravity of a fully loaded
pack, enabling it to stand upright easily on its bottom shelf when
placed on uneven ground
[0009] The backpack disclosed by Gregory in 5,564,612 shows an
external frame with parallel tubular side rails connected with
plastic castings and a closed top that does not allow hanging
hiking gear, as does the present invention. The Gregory pack has a
single bag utilizing side pockets, the bag being loosely attached
to the side tubes at several attachment points and suspended from a
loop at its top. The stresses on the fabric and seams at this top
loop are very high, requiring the use of heavy fabric for
durability. The Gregory pack frame has a bottom loop but this loop
is intended to support a sleeping bag and does not ride in contact
with the pack bag and does not support any bag weight. The hip belt
attaches in part to a plastic casting at the center of the back,
but this casting is not curved to fit the lumbar region, instead
relying on thick padding in the hip belt for comfort.
[0010] The Front Pack disclosed by Stanford in 4,480,775 offers a
rigid bottom loop intended to support the weight of a loaded bag.
However, this front pack places no weight onto a waist belt,
putting all weight on two shoulder straps and is not paired with a
backpack as enabled by the present invention. The Ergonomically
Enhanced Backpack by Lemire in 6,179,187 discloses a knapsack with
a dorsal plate that is similar to the lumbar insert of the present
invention, however this knapsack lacks the external weight bearing
tubular frame of the present invention that is necessary to carry
heavy loads in comfort. The dorsal plate is intended to intimately
contact the hiker's back from below the shoulder blades to the
pelvic region. The large area of this dorsal plate makes it both
heavy and hot and also unlikely to fit the large range of human
body sizes and shapes.
[0011] The invention in 4,561,578 (Bell) discloses an external
tubular weight bearing frame with a set of balance rods which are
intended to manipulate the shoulder belts. The balance rods are a
heavy and complex means of adjusting the shoulder belts where the
present invention offers automatic shoulder belt adjustment with no
added weight or complexity. The Bell device also places a large
portion of the pack weight upon the shoulders, causing discomfort
in the majority of hikers.
[0012] The Kober disclosure of 5,628,437 offers a combination of a
backpack and a seat. The seat cushion is bulky and heavy and serves
no function while the device is used as a backpack. The disclosure
of 4,489,866 also shows a pack that has swiveling tubes that can be
configured into a chair. The present invention allows its necessary
lumbar padding to be swiveled and also used as a seat cushion and
adds no tubing for the exclusive enablement of a seat.
[0013] The Tramper's Pack of 6,276,584 discloses an internal frame
pack that intends to focus the weight of the pack on the lumbar
region. However, this design lacks both the external tubular frame
and the multi-compartment bag of the present invention, making it
difficult to implement without excessive bag weight to attempt to
focus all weight zones of the pack into the lumbar region.
[0014] Patent application 2002/0100778 pictures a molded pack frame
that includes a curved lumbar panel that pivots within the outer
frame. This pack frame converts into a chair. The weight of a
molded frame of this complexity will be very high and will overcome
any benefits of its claimed features. The molded frame does not use
a bag with compartments sharing no fabric panels. The molded frame
is not narrower at the top to improve the center of gravity. The
conversion to a chair requires removing the pack bag where the
present invention leaves the bag in place and uses the pack bag as
a padded seat back.
[0015] The patent application 2002/0108982 offers a knapsack
without an external frame and adds control rods to decouple the hip
motions from the backpack. This adds weight and complexity that the
present invention cures by using a stiff lumbar insert with stiffly
attached belt that encircles and compresses the torso above the
pelvic bones.
[0016] The invention of application 2002/0074373 adds a bionic
mechanism to tighten the hip belt using the mechanical advantage of
pulleys. This purports to so tighten the hip belt that the wearer
can bear many times the normal pack weight. The drawback of this
device is the weight and complexity that serves only to make the
waist belt far too tight for any hiker to bear. The present
invention uses a hip belt with a 2:1 mechanical advantage at the
front attachment point as is typically found on low cost exercise
belts. This 2:1 advantage is sufficient to easily tighten the waist
belt for the optimal compression of the torso and can be, with only
a 2:1 advantage, over-tightened to the point of discomfort for even
the most fit hiker.
SUMMARY OF INVENTION
[0017] The invention is a hiker's backpack utilizing a rigid
external frame to which is attached a multi-compartment bag
comprised of multiple horizontal cylinders that share no common
structural panels. The bag is mounted in a way that reduces stress
on the seams thus allowing thinner and lighter materials to be
used. The frame is typically comprised of metallic and composite
elements and exhibits very little flex. The frame has a horizontal
bottom loop comprising a shelf that bears the weight of the bags
and also allows the loaded backpack to stand by itself on the
ground. The two side tubes of the frame are slanted inward towards
each other at the top lowering the load's center of gravity and
making the pack narrower and easier to maneuver in the brush. The
two side tubes rise above the topmost compartment of the bag to
provide a hanging fixture for other hiking gear. The frame has a
waist belt that can incorporate an ergonomically curved polymer
insert to direct the majority of the weight of a loaded pack onto
the lumbar curve of the spine. The insert is padded with a panel of
cushioning material that can be repositioned to form the base of a
camp chair while the bag forms the back of the chair.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1--Side view of frame and bag as worn by a hiker.
[0019] FIG. 2--Front view of frame with all belts showing the
V-tube attachment and lumbar padding.
[0020] FIG. 3a--Frontal view of hiker wearing backpack with a
frontpack.
[0021] FIG. 3b--Side view backpack used as a camp chair.
[0022] FIG. 4--Detail view of waist belt with lumbar element and
attachment means.
[0023] FIG. 4a--Cross-sectional view of means of attaching waist
belt to frame showing lumbar element, external frame, hook &
loop fasteners and padding.
[0024] FIG. 4b--Detail view of 2:1 waist belt front attachment
means.
[0025] FIG. 5--Rear view of bag as mounted on frame.
[0026] FIG. 6--Side view of backpack showing "C"-tube attachment
devices.
[0027] FIG. 6a Cross-sectional view of "C"-Tube attachment
device.
DETAILED DESCRIPTION
[0028] Referring to FIG. 1, the backpack of the present invention
is a backpack for humans to carry a load, utilizing a rigid
external frame 26 to which is attached a bag with multiple
compartments 12. The bag 12 is typically constructed of waterproof
fabric, but can alternatively be constructed with plastic films,
netting, mesh, thin metal sheet or molded plastic. The bag 12 has
multiple compartments of preferably cylindrical geometry mounted
horizontally to the frame where the compartments share no common
structural panels. The shape of the individual compartments can be
constructed to be other than cylindrical, but after being stuffed
with gear, an unconstrained compartment of lightweight fabric will
assume a nearly cylindrical shape. A cylindrical geometry will
achieve the lowest bag weight for a given volume.
[0029] The frame is typically comprised of metallic and composite
elements, usually tubular, but can be made with any light weight
material, such as wood, magnesium, aluminum, carbon fiber, fiber
glass, and molded plastics. The frame is rigid to efficiently
transmit load vectors to the lumbar region of the hiker's back. The
frame has a bottom loop 15 forming a shelf that bears the weight of
the loaded bags and also allows the backpack to stand by itself on
the ground. The two side tubes of most external frame backpacks are
parallel in the rear view and are curved to match the human spine.
In FIG. 2, the two side tubes 24 of the frame 26 of the present
invention can be curved to match the spine but can also be
straight; but, in either case, are slanted in the rear view to be
narrower at the top to lower the loaded pack's center of gravity
and make navigating on tight trails easier. The two side tubes 24
rise above the topmost compartment of the bag 12 to provide a
hanging fixture for other hiking gear such as a front hydration
pack 32 in FIG. 3a, hiking sticks, or a dog leash. The front
hydration pack 32 has two straps that hang from the top of the two
sides tubes 24 that extend above the junction of the V-tubes 23. In
addition, the bottom of the front pack attaches to the waist belt
13 with a strap or buckle that bears the majority of the weight of
the front pack. The weight of the front pack counterbalances an
equal weight of the backpack, resulting in the hiker being able to
stand more upright to maintain the center of gravity necessary for
comfortable walking.
[0030] The frame 26 has attached to it near the bottom a waist belt
13 that can incorporate an anatomically curved insert 55 shown in
FIG. 4a to bear the majority of the weight of a loaded pack on the
lumbar curve of the spine, as shown in FIGS. 4 and 4a. The insert
55 is preferably by Flex Form, U.S. Pat. No. 5,445,601. The insert
55 is padded with a panel of cushioning material 25 that can be
swiveled about the anterior tube 31 of the bottom loop to form the
base of a camp chair, FIG. 3b, with the pack bag 12 forming the
back of the chair.
[0031] In FIG. 2 and FIG. 4b, the external frame 26 of the present
invention also has two shoulder straps 21 attached to it. The ends
of the shoulder straps attach near the bottom and near the top of
the frame. The preferred bottom attachment point is to a horizontal
tube 51b that runs between the two side tubes 24. Or,
alternatively, the shoulder strap lower end can be bolted or pinned
to other frame tubes. The top section of the external frame may
also have one or more horizontal tubes between the two side tubes.
In addition, a V shaped tube 23 is attached between the side tubes
at the top. The top end of each shoulder strap 21 is attached in a
manner that allows it to slide along the V tube member 23 on each
side of the hikers neck. This allows the hiker to change the width
of the shoulder strap mounting point while walking to maximize
comfort. Or, if left untended, the shoulder belts tend to slide
along the V tube to the optimum position for the hiker; a shorter
hiker will see the straps slide down the V tube to a narrow
position while a taller and bigger hiker will have a neck and
shoulders that will push the attachment points upward and
outward.
[0032] On the present invention, the vertical distance between the
waist belt 13 and the V tube 23 is greater than the distance found
on a typical external frame backpack such as the Kelty models and
is such that the shoulder belts do not touch the top of the hiker's
shoulders, even for tall hikers. The shoulder straps 21 attach at
an upward angle from horizontal, not a downward angle. This allows
one size of backpack to fit all customers. The shoulder straps 21
provide stability to the pack to limit pack movement while walking.
The straps 21 provide a weight bearing ability only if they are
adjusted very tight to allow the pectoral muscles of the chest to
bear some component of the compression force. This high mounting
level of the V tube 23 and shoulder straps 21 eliminates one of the
biggest complexities of other backpack designs--the requirement for
different size frames to match the differing torso lengths of the
human population. The present invention solves this problem in the
same manner that the automotive seat/shoulder belt solves an
identical problem. The shoulder strap mounting geometry of the
present invention is similar to that used in cars for safety belts.
While traditional backpacks are offered in many sizes, cars come
with only one seat size to fit all drivers. One safety belt and one
seat size fits all drivers because the waist belt is adjustable and
the shoulder belt does not arch down over the shoulder, it angles
straight up across the pectoral region to a high attachment point
on the frame of the vehicle. The backpack of the present invention
offers a similar geometry allowing it to be offered in only one
size that will fit children and adults, men and women. This allows
a family to share or swap backpacks and also reduces inventory
costs for manufacturers, distributors, and retailers.
[0033] The frame of the present invention offers several
improvements. The two side tubes 24 of the external frame 26 are
not parallel in contrast to the external frame packs in the
citations which are generally rectangular in the posterior view
causing the wide upper section to catch on branches along the
trail. The present invention slants the side elements of the frame
inward towards each other at the top. This makes the top of the
frame narrower than the bottom by typically several inches allowing
tight spaces to be negotiated more easily by the hiker. Another
advantage of a frame with a narrow top is the resulting smaller
volume of the pack bag at the top. This reduces the gear weight in
the top of the pack, making it easier for the hiker's natural
balancing skills to re-balance the load over his center of gravity
with each step, thus reducing or eliminating thousands of small
muscle exertions that produce fatigue.
[0034] The frame of a typical external frame backpack will show a
loop of metal or a plastic casting across the top to allow lashing
gear on top of the pack bag. The frame of the present invention
does not have this loop; the ends of each side tube 24 extend free
of the pack bag by several inches, creating a post several inches
tall. These two posts are very useful to the hiker as they provide
a convenient point from which to hang gear. For instance, many
hikers are using one or two telescoping hiking poles to improve
hiking stamina. These poles are very inconvenient at times, such as
when the hiker needs to use a camera or compass. A hiking pole can
be quickly hung from the frame posts 24, even while walking, to
free up a hand to use other equipment. Hydration packs 32 are also
very popular with hikers and are easily hung from the frame posts
24. Other items like towels, shoes, rain ponchos, and hats are
easily hung from the frame posts. The hiker does not have to stop
and take his pack off to retrieve an item; this allows the hiker to
keep walking at a steady pace and increase the mileage covered each
day.
[0035] A critical metric of any backpack is its weight. Every ounce
is critical to the distance hiker. The external frame 26 of the
invention is typically built from high strength thin wall aluminum
tubing and/or carbon fiber tubing. The resulting frame becomes a
rigid load transfer diaphragm that delivers the maximum stiffness
at the least weight of any pack design. A typical frame 26 of the
present invention will weigh 12 ounces if made of carbon fiber
tubing and be capable of carrying a gear load of 75 pounds without
distortion. Carbon fiber tubing is very light and stiff but is also
very brittle resulting in breakage at the joints when overstressed,
for instance, by dropping a fully loaded pack on a rock surface.
Rugged joints are achieved by using socket joints for right angle
joining of carbon fiber tubes. These joints are bonded with two
part marine epoxy filled with phenolic microballons for light
weight and silica powder for flexibility and bonding strength. The
joint 43 in FIG. 4b shows the horizontal member 51b is inserted
into a hole drilled in the vertical member 24 of a larger diameter.
The hole in the tubular vertical member 24 is drilled through only
the inside wall. The tubular horizontal member 51b is inserted into
the hole in vertical member 24 after the hole is filled with epoxy
bonding agent. In the case of a frame using all aluminum or
magnesium tubing, the tubing joints can alternatively be
welded.
[0036] Another improvement is the geometry of the pack bag 12,
comprising four horizontal fabric cylinders, such as 61 and 62 in
FIG. 6, that are not connected or, alternatively, loosely connected
to each other but are loosely connected to the frame side tubes 24
of the frame 26. These bags rest on a rigid bottom loop or shelf 15
that supports all the gear weight, resulting in almost no stresses
on the straps 17 that attach the bag to the frame. Typical external
frame backpack designs produce high point loading by using several
attachment pins from which all the gear weight must hang. This will
ultimately result in torn fabric at the attachment pins. In the
late 1960's the Gerry Company sold an external frame backpack with
a rectangular fabric bag divided into four horizontal sections
accessible with zippers and utilizing sewn-in shared fabric
dividers. Such a pack is owned by the inventor and this pack did
tear at the immovable attachment pins because it did not utilize a
bottom loop on the frame to bear the weight of the loaded pack.
[0037] The fabric bag 12 can be used without the frame as a pack
bag for a bicycle, motorcycle, or in a canoe. In this case, the
individual cylinders must be connected together. Referring to FIG.
6a, the preferred means of connecting the multiple cylindrical
compartments of the bag together is a "C" tube 63 and rod 64 that
slip over the fabric of two adjoining cylinders 61 and 62 at any
place on the circumference of the fabric cylinder. This allows the
multiple compartment bag to be reassembled to easily bend into a
curve and conform over a luggage rack on a bicycle or the seat on a
motorcycle. When attached to the external frame of the invention,
the cylindrical bags can be left unconnected to each other to allow
fast removal and re-attachment of a single cylinder during a hiking
trip.
[0038] The rigid bottom loop 15 of the frame 26 also allows the
pack to stand up on its own when the hiker sets it on the ground
where most packs tip over when set down. In addition, the bottom
loop 15 has a pad 25 (FIGS. 2 and 3b) hinged around the anterior
tube 31 of the bottom loop 15. This pad is swiveled forward to pad
the lumbar insert 55 when the pack is being worn. The pad 25 can be
swiveled to the rear as the pack is set on the ground and used as a
seat pad with the pack bag 12 forming the back of a chair. This can
reduce the gear weight the hiker is carrying by eliminating the
need to carry a camp chair or stool. The pack in this configuration
as shown in FIG. 3b requires no additional straps or tubing to
connect the seat pad to the pack frame. The chair configuration is
self-supporting as weight on the seat pad places downward pressure
on the anterior tube 31 of bottom loop 15 while weight on the pack
bag from leaning back produces an equal upward pressure, thus
causing the chair to be stable over a wide range of lean
angles.
[0039] The foremost complaint of long distance hikers is pain from
the hip belt and shoulder straps of all three categories of packs.
The present invention optionally incorporates a lumbar support that
can eliminate this complaint in most hikers. In FIGS. 4 and 4a, a
stiff plastic insert 55 molded to fit the curve of the lumbar
region of the body is attached at the center of the frame near the
bottom using hook and loop tape 56. The insert 55 is covered with a
thin padded panel 25. Traditional external frame packs refer to the
horizontal belt as a hip belt. The present invention mounts the
belt 13 to the frame at point above the lumbar insert 55. This
causes the waist belt 13 to encircle the waist like a cummerbund,
instead of hugging the hips. In addition, the waist belt is
typically constructed of a foam/fabric laminate that is stiff and
holds its shape without wrinkling as it pulls the frame 26 towards
the body as it runs behind vertical frame sub-elements 52. The
waist belt is attached to the frame very stiffly using multiple
layers of wide hook and loop tape 54 wrapped around horizontal
frame tubes 51a and 51b so that the belt does not twist or flex in
the attachment area. Typical backpack belts are attached to the
frame with two or four small flexible nylon straps allowing the
belt to flop around freely from the frame producing an unstable
pack that moves with each step.
[0040] The primary function of the belt 13 is not a means of
transferring weight to the hip bones, but becomes a compression
strap to stabilize the torso and pull the molded insert 55 and
padding 25 tightly against the lumbar curve of the spine. Looking
at FIG. 4b, the compression is generated when the hiker pulls strap
42 through loop 41 generating a 2:1 mechanical advantage to shorten
the strap. Alternatively, a traditional side-release buckle can be
used, instead of the plain loop, to allow a quick release of the
waist belt. The end of strap 42 has a hook and loop patch to attach
to a mating hook and loop surface on belt 13. The stiffness of the
belt-to-frame attachment in FIGS. 4 and 4a keeps the frame from
vertically twisting the belt 13 and also prevents the frame from
rocking from side to side with each step the hiker takes. The
combination of a lumbar insert 55 and a stiff attachment allows
most of the pack weight to be borne by the lumbar curve of the
spine, a point that exhibits little motion during walking and also
the point that is closest to the body's natural center of gravity.
In contrast, packs with hip belts designed to transfer weight to
the hip bones put the weight at the outer edge of the body at a
point that is in constant motion. The waist belt 13 typically
produces compression that falls between the top of the pelvic bones
and the bottom of the rib cage. This is an effect similar to the
belts used by weight lifters and the back belts worn by factory and
warehouse workers who must lift heavy weights all day long. The
lumbar insert 55 can be removed from the waist belt 13 by peeling
the hook and loop tape 56 apart and can be reattached an inch or
two up or down, thus positioning the waist belt to maximize the
personal comfort of each individual hiker. In FIG. 2, backband 22
is typically a hook and loop strap that wraps around the two side
tubes 24 of frame 26. Backband 22 is tensioned by sliding it down
the side tubes 24 which diverge towards the bottom of the frame.
This eliminates the typical cords and knots needed to tension the
backband. The backband 22 prevents the tubes comprising frame 26
from pressing on the hiker's back if the shoulder straps 21 are set
to a tight position.
[0041] Referring to FIG. 5 and FIG. 6, the fabric bag 12 solves the
drawback of internal frame packs on the market that are difficult
to pack up and unpack. The bag 12 typically has four horizontal
compartments, but can utilize as few as one or more than four
depending on the needs of the hiker for each trip. Each compartment
such as 61 and 62 will have its own full length zipper or hook and
loop closure 65 or can alternatively use a radial zipper on one or
both ends of the cylindrical compartment. A hook and loop closure
will typically also use one or two side release buckles to prevent
accidental opening of the hook and loop. The upper cylinders are
not as wide as the lower cylinders to match the narrower top of the
frame 26 near the hiker's shoulders. Each compartment is sewn into
a cylinder independently and then attached to the frame 26 with
hook and loop tapes 17 to form the final pack bag 12. Or,
alternatively, the cylinders can also be attached to each other
using the C-tube 63 and 64 in FIG. 6a, or the cylinders can be sewn
to each other. This geometry produces a bag that has no shared
panels of fabric. This is an improvement over pack bags that
utilize sewn-in dividers or multiple pockets. Such bags allow gear
packed into one section to intrude into the space of another
section and typically produce high stresses on the internal seams
resulting in tears or pulled seams. The individual cylinders are
typically made with waterproof coated nylon thus also delivering
the benefit of liquid spills being confined to only one cylinder,
preventing, for instance, stove fuel from contaminating all the
gear, as would happen in a typical pack bag. The individual
cylinders of the bag 12 of the present invention are not attached
firmly to the frame at any point. Mounting straps 17 are free to
float up and down on the side tubes 26 of the frame. The bottom
loop shelf 15 of the frame supports almost all the weight of the
gear. This reduces the stresses on the fabric and the seams of the
cylinders to a very low level, allowing the use of thinner, lighter
fabric without reducing reliability. The bag 12 can have lashing
pads 66 sewn to the fabric to carry items like a fishing pole or an
ice axe. In contrast, the bags of a typical internal frame pack are
heavily reinforced because many seams are highly stressed with each
hiking step. The bag 12 typically weighs less than one pound where
the bag alone of an internal frame pack will typically weigh about
four pounds.
[0042] The multiple cylinder bag 12 allows the hiker to choose
different widths and diameters to match the pack volume to the gear
to be carried on each hiking trip. The cylinders can stacked on the
frame without any cylinder-to-cylinder attachment. For a more rigid
bag, the cylinders can be attached to each other. The attachment
interface between two cylinders such as 61 and 62 is generally
towards the rear plane of the pack, but can be at any radial
position between the gear access zipper 65 and the loops 17 that
attach the fabric cylinder to the frame 26. The preferred
attachment method is a "C" tube 63 and rod 64 device that slips
over a fold in the fabric of the two adjoining cylinders. The "C"
tube and rod device eliminates water leaks from sewing needle
punctures. This attachment device can be moved easily by the hiker
to optimize the geometry of the bag 12. Or the attachment method
can be sewing, hook and loop, tie loops, zipper, or similar
methods. Or alternatively, the fabric cylinders can be attached
along two lines typically 4 to 6 inches apart radially to construct
a more rigid bag that does, however, deliver less volume because
the cylinders are constrained from each achieving a fully circular
shape.
[0043] The cylindrical shape of the bag compartments is a natural
fit with the typically cylindrical shape of hiking gear such as
sleeping bags, tents, and sleeping pads. Animal resistant food
canisters are typically also cylindrical in shape. This results in
more efficient packing that eliminates wasted volumes. The
full-width closure 65 allows immediate access to any gear without
disturbing other gear. The closure can utilize a zipper, hook and
loop tape, or snap buckles, or a combination.
[0044] While the particular backpack, as herein shown and disclosed
in detail, is fully capable of obtaining the objects and providing
the advantages above stated, it is to be understood that the
presently preferred embodiments are merely illustrative of the
invention. As such, no limitations are intended other than as
defined in the appended claims.
* * * * *
References