U.S. patent number 3,563,431 [Application Number 04/773,912] was granted by the patent office on 1971-02-16 for self-adjusting.
Invention is credited to Murray J. Pletz.
United States Patent |
3,563,431 |
Pletz |
February 16, 1971 |
SELF-ADJUSTING
Abstract
A packframe for hikers is constructed using side and
cross-members rigidly held together by tension created in straps
wrapped around the frame. The packframe has shoulder straps
anchored at both ends to substantially a common point near the
bottom and out from the general load bearing area of the packframe.
A belt is coupled near the bottom of the packframe to absorb a
portion of the load and to stabilize the packframe.
Inventors: |
Pletz; Murray J. (Bellevue,
WA) |
Family
ID: |
25099696 |
Appl.
No.: |
04/773,912 |
Filed: |
November 6, 1968 |
Current U.S.
Class: |
224/262;
224/263 |
Current CPC
Class: |
A45F
3/08 (20130101) |
Current International
Class: |
A45F
3/08 (20060101); A45F 3/04 (20060101); A45f
003/08 () |
Field of
Search: |
;224/6,25,25.1,8,9,11 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Forlenza; Gerald M.
Assistant Examiner: Werner; Frank E.
Claims
I claim:
1. A backpack for hikers comprising: a frame including
laterally-spaced rigid side members for extending from the waist to
above the shoulders, an adjustable upper crossbar having its ends
slidably mounted on said sidemembers for locating it at about
shoulder height of a given hiker, locking means on the ends of the
crossbar and engaging the sidemembers for selectively fixing the
crossbar relative to the sidemembers in cross-bracing relation, and
a lower crossmember interconnecting the sidemembers toward their
waist end; a pair of laterally spaced shoulder strap means each
secured at its opposite ends to said frame near said crossmember
and forming a respective shoulder loop to the front of the frame;
strap positioning means mounted on said frame and connected to said
shoulder strap means at the back of their loops in a location
closely adjacent to said adjustable crossbar, said strap
positioning means being restrained by said adjustable crossbar
against downward movement relative thereto and being movable
therewith along the frame when the crossbar location is adjusted,
and being adapted to keep said strap loops equally spaced from the
respective sidemembers and to hold the back of the loops closely
adjacent the crossbar to restrict lateral or rearward shifting or
twisting of the pack relative to the shoulder loops when in use;
and strap length adjusting means on said shoulder strap means for
varying the effective length thereof.
2. A backpack according to claim 1 in which the control portion of
said lower crossmember extends rearwardly of the sidemembers as a
shelf and the ends of the shoulder strap means are anchored
thereto.
3. A backpack according to claim 1 in which said upper crossbar
comprises a pair of slide blocks slidably mounted on said
sidemembers and carrying said locking means and a bar having its
ends slidably received by said slide blocks; and cushioning cinch
means passing around said sidemembers and holding said bar in the
slide blocks.
4. A backpack according to claim 3 in which intermediate
crossmember means are socketed at their ends to the sidemembers and
are held in socketed position by said cinch means.
5. A backpack according to claim 1 in which said strap positioning
means comprises a cross strap secured at laterally spaced locations
to said pair of shoulder strap means and sleeved at its ends on the
sidemembers immediately above the upper crossbar.
Description
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for transporting loads
on a man's back. Specifically, the present invention relates to an
improved packframe which effects optimum distribution of a load to
the body utilizing simplified versatile structure.
It is commonly understood that a load is most easily endured by the
human body if it is positioned above the shoulders and close in to
the neck. Placement of the load in this manner directs the weight
through the shoulders and torso to the hips enabling the strongest
body muscles to bear the major bulk of the burden. Prior art
packframes seeking to effect the foregoing load placement have
employed complicated frame structures and elaborate shoulder
harnesses.
Accordingly, it is an object of the present invention to construct
a packframe of simple and economical structure and assembly capable
of optimumly distributing the weight of a load to the body. To
accomplish this objective the present invention employs a generally
L-shaped frame having shoulder straps for absorbing most of the
load anchored to a fixed position on the foot of the L with an
adjustable takeoff point on the leg of the L. A waist belt is
coupled to the frame near the foot of the L to secure the lower end
of the packframe to the body and to absorb a portion of the
load.
It is another object of the present invention to construct a
packframe which can be readily altered in size to accommodate
different types of loads and for use in different environments. It
is also an object to construct the packframe so that it may be
completely disassembled in the field so that the component parts
can be employed for other uses. These objects are accomplished by
constructing the packframe from interlocking parts held in place by
the tension forces developed in the shoulder straps and other
straps holding comfort pads against the back of the packbearer.
Accordingly, another object is to design a packframe having a
flexible frame structure capable of absorbing shock when dropped to
the ground or the like while fully loaded. Even a further object is
to devise a packframe which can be completely disassembled to
facilitate its storage.
Yet another object of the present invention is to devise a
packframe which tends to urge the load of the packframe close to
the body. It is also an object to construct the packframe to enable
the packframe to be properly used by different bearers.
Another object of the present invention is to provide improved
means for coupling a packframe to the body including a belt which
is snugly wrapped around the body and couples to the packframe via
means extending from the packframe inward to the belt.
DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become
apparent from a further reading of the description of the invention
as well as from the drawings which are:
FIG. 1 is a perspective view of the packframe of the present
invention mounted on the back of a hiker;
FIG. 2 is a side elevational view of the packframe and hiker shown
in FIG. 1;
FIG. 3 is an exploded perspective view of the present packframe
illustrating interconnection of the various components;
FIG. 4 is a cross section view of the packframe taken along line
4-4 in FIG. 2;
FIG. 5 is a cross section view of the packframe taken along line
5-5 in FIG. 2; and
FIG. 6 is a cross section view of the packframe taken along line
6-6 in FIG. 2.
DESCRIPTION OF THE INVENTION
The present packframe is versatile structure. It is designed to
distribute in an optimum manner the weight of a load to the body.
The packframe harness is readily adjusted for comfortably fitting
the packframe to the unique body build of a user. The construction
of the packframe permits complete disassembly allowing the various
components to be used for as diverse purposes as an extension for a
frying pan handle to a frame for a tent. Extension members are
readily coupled to the packframe to expand its size. The expanded
frame may be necessary for longer or peculiar loads or for
positioning the load higher above the shoulders. The load normally
is carried in a packsack attached to the frame but can be tied
directly to the frame.
A packsack intended for use with the present frame is a tapered
rucksack. A rucksack is a packsack carried without a packframe
commonly used for short hikes or the last leg of a climb by a
mountain climber. The present rucksack is tapered, narrower at the
top than at the base, for fitting generally between the shoulder
blades. A flap, having eyelets for engaging with clevis pins along
the sides of the present packframe, is sewn onto each side of the
rucksack to give a generally rectangular shape to the tapered
rucksack. As a result the rucksack can be carried on the present
packframe along with other packsacks during the early portion of a
hike or climb and can be removed and carried alone on the final leg
of the trip.
If the center of gravity of the load is above the height of the
shoulders there is a natural tendency for the load to pivot about a
point near the shoulder blades toward the neck and head. This
maintains the load in the desired position close to the body. The
harness of the present packframe is arranged to assist this natural
tendency.
The packframe includes an L-shaped base, a waist belt and shoulder
straps. The base is the structure to which the load is attached.
The base is appropriately contoured to conform generally to the
contours of the human back. The contoured shape as well as pads
abutting the back of the pack bearer are incorporated for the
comfort of the bearer.
The foot of the L-shaped base is a shelf which serves as a stand
for the pack as it rests on the ground and which aids in securing
the load to the packframe. Most importantly, however, the shelf
provides an anchor point for both ends of the shoulder strap that
is out from the general plane of the base (the leg of the L). The
base also includes an adjustable crossbar which is positioned
generally to the height of the user's shoulder blades. The shoulder
straps are continuous loops anchored to points out on the shelf.
The upper portions of these loops pass over the adjustable
crossbar. The tension in the shoulder straps created by the load
tends to straighten the upper portion of the straps passed over the
adjustable crossbar. The straps in turn tend to rotate the bottom
of the base outwardly so as to position the load at the top of the
packframe closer to the body. The tendency is for the base to
rotate about the crossbar and this tendency is accentuated by
anchoring the straps out on the shelf away from the general plane
of the base.
The belt is connected to the base near the shelf to distribute a
portion of the load directly to the hips and thighs. Both the
length of the shoulder straps and belt are adjustable to
accommodate the physique of a particular pack bearer. The straps
and belt are heavily padded not just for comfort but also for ease
of coupling to the body. The heavy padding makes them relatively
tangle-free permitting the user to readily engage them about his
body. The straps and belt are coupled to the body by a tape locking
mechanism available under the trade name "Velcro."
The present packframe is a knockdown packframe. By knockdown is
meant that the packframe is capable of being readily disassembled
into its component parts. The knockdown feature is obtained by
interlocking the components by interfitting the components into
slots and holding them in place by compression straps and cinches.
The knockdown feature of the packframe permits the various
components to be freed for other uses and facilitates storage.
Packframe 1 is formed from base 2, shoulder straps 3 and belt 4.
Base 2 includes S-shaped tubular sidemembers 6, U-shaped tubular
crossmembers 7, tubular top member 8, tubular shelf member 9,
adjustable crossbar 10, blocks 12 and padded cinches 16.
The shoulder straps include web 13, pads 14, eyelets 17 and buckles
18. The shoulder straps also include crossweb 19 having loops 21 at
each end thereof which is sewn to the straps at points 22. The
loops fit over the sidemembers 6.
The belt 4 includes web 23 for coupling to the side members 6, web
24 sewn to web 23 at points 25 and pads 27.
FIG. 3 illustrates the interconnection of the base components. The
side members 6 define the leg of the L-shaped base and the shelf
member 9 defines the foot of the L-shaped base. Tubular extension
rods (not shown) are coupled between sidemembers 6 and top member 8
to expand the size of the packframe. Top member 8 and shelf member
9 are turned on a lathe to reduce their outside diameters near the
ends for insertion into the hollow of the sidemembers The top and
shelf member telescopically coupling the components together are
locked to the sidemembers by clevis pins. The shelf member, as seen
in FIGS. 2 and 3, is curved at the corners 15 in the plane of the
shelf to minimize damage to a loaded packframe dropped to the
ground. The curves at the corners of the shelf eliminate the lever
arm presented by a sharp corner. The aluminum frame could possibly
bend under the weight of the load acting through the lever arm
distance of the corner.
The shelf member 9 extends generally perpendicular from a plane
defined by the sidemembers 6. The sidemembers are of a length to
extend generally from the area of the user's waist to above the
height of the user's shoulders.
Blocks 12 and loops 21 are slid over the sidemembers 6 prior to
coupling the top and side members together. Bore 29 is provided to
enable the insertion of a block over a sidemembers. Blocks 12
support the crossbar 10 which is inserted into bores in the blocks.
Blocks 12 include the threaded bore 31, plug 32 and setscrew 33.
The setscrew forces the plug against the sidemembers to lock it to
a specific location. The setscrew is backed out of the threaded
slot to permit the crossbar to adjust to the position on the
packframe corresponding to the shoulder blade height of the user.
FIG. 5 shows a block locked to a sidemember.
FIG. 4 illustrates the coupling of a crossmember 7 to the
sidemembers 6. The crossmembers include spade ends 35 which mate
with slots 36 in the sidemembers. The crossmembers 7 are held in
compression between the sidemembers by padded cinches 16. The
cinches 16 are looped about the sidemembers and are tightly drawn
to hold the crossmembers in compression. The cinches in combination
with the side and crossmembers make a rigid structure yet one
capable of receiving shock without damage. Since the cross and
sidemembers merely are fitted together, the frame is able to flex
or give if it is dropped to the ground while a load is attached. A
similar shock could sever a weld or other rigid joint as found on
prior art packframes.
A packsack is attached to the frame by the clevis pins 20
positioned through bores in the sidemembers The clevis pins are
locked in place by the long pin 37.
The shoulder straps 3 are anchored at both ends by clevis pins 20
to the shelf member 9 as seen in FIG. 6. The upper portions 38 of
the straps extend from the shelf, beneath the crossmembers and over
the adjustable crossbar (FIG. 2). The pads 14 extend over the
user's shoulders back to the shelf. The lower portion 39 of the
straps includes buckle means for adjusting the length for a
particular user. The load on the packframe is primarily absorbed by
the shoulder straps and is transferred by the straps from the
anchor point on the shelf to the user's shoulders. The
concentration of the load at the anchor points creates a tension in
the straps that tends to straighten the upper portion 38 thereby
rotating the entire packframe. The packframe therefore tends to
maintain the load in the desired position close in to the body.
The straps 3 include crossweb 19 which is coupled to the
sidemembers 6 by loop 21. The straps still form continuous loops
tied to the shelf because the crossweb 19 does not receive the
weight of the load. The crossweb maintains the two shoulder straps
at fixed, spaced apart positions. In addition, it serves as means
for compressing the packframe in the direction of the height of the
user. Buckles 18 are provided to permit the strap web 13 to
compress the packframe in an axis perpendicular to the compression
generated by the padded cinches 19. The structural strength of the
packframe is thereby increased. The pads 14 form part of the
shoulder straps and contribute to the user's comfort as well as
being tangle proof.
The belt 4 is coupled to the packframe by clevis pins 20 fitted
through bores 36 in the shelf 9 as illustrated. The eyelets in web
23 are used to attach the belt to the shelf member. Web 24 is sewn
to web 23 as shown at point 25 and is in turn coupled to pads 27
which extend about the user's waist. The belt tends to stabilize
the packframe on the back of the user.
It is believed that the invention will have been clearly understood
from the foregoing detailed description of my now-preferred
illustrated embodiment. Changes in the details of construction may
be resorted to without departing from the spirit of the invention
and it is accordingly my intention that no limitations be implied
and that the hereto annexed claims be given the broadest
interpretation to which the employed language fairly admits.
* * * * *