CA1077899A - Backpacker's device - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A backpacker's device characterized by a frame structure having a central weight-bearing leg which terminates in a lower foot, and two lateral weight-bearing legs, one of either side of the central leg, each terminating in lower ends and connected to the central leg remote from the lower foot and lower ends.
The frame structure is formed of a single bar in a generally M-shaped configuration. The lateral legs of the frame are preferably flexible. Other preferred embodiments include a contoured profile in the frame, a hip belt to which the weight-bearing legs of the frame are attached in a particular relationship, a rigid belt-reinforcing strap to prevent excessive lateral movement of the frame lower ends, and a packbag secured on the frame in a particular relationship.

Description

78~3~

sAcKGRou~D OF ~ NTIOI~
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This invention relates to ~he ield of backpacking equip-ment and in partlcular to devices by which backpackers can carry loads.

In the ~iQld of thi~ inven~lo~ the ~adder or "H" type ~rame to which packbag are mounted has been predominant fvr many years. Such frames are normally made from rlyid hollow bars welded together ~or connected together in some other fashion) in the popular ladder or "H" configuration, which usually includes two parallel vertical members and two or more parallel horiæontal cro~s members. While 3uch pack frames are widely u~ed, there are 5ubstantial problem~ a550ciated therewith.

The ladder or "H" type frame was developed years before the daYelopment of the sophis~icated packbags now popularly used in co~junc~ion with such frame~. The ladder frame was developed at a time when it was necessary fox a packer to lash articles to hi~ pack frame. Usually the articles he want d to carry were collected and wrapped in a poncho, ground sheet or shelter sheet to form one or more bundles which were then lashed wi~h cord to the frame for tran~porting. Since it was of primary importance that nonè of the packed article~ become dislodged or lost along the trail, the packer put much emphasis on tying and lashing secure-ly. The frame~, therefore, had to withstand forces o~ con~iderable magnitude gen~rated by lateral, vertical and/or diagonal lashings.
To with~tand thi3, the pack frame had to ha~e ~ubstantial rigidity and be strong enough ~o withstand la~hing stresses- The ladder or "~ ype pack frame con~igura~ion provided the neceR~ary rigidity and s~reng~ll for ~his purpose.

~2 8~ "

Since that timQ; apecial packbacJs for use with pack frame~ hav0 been developed ~ox contai~n~n~ o~ ~he ar~icle~ normally carried by the packer. These ba~s can be mounted ~o khe frame in ~uch a way that the stresses formerly imposed by lashing have been elimlnated or at least ~ed~ced and more evenly di~tributed o~er the frame. Further, during the same period o~ time there have been improvements and refinements in the equipment and articles o ood carried by the packer which have ~ubstantially reduced the weight of the typical load to be carried. A reduction in weight also tends to further reduce the need for rigidity in the ~rame.

There are certain di3advantages as~ociated with rigidity of pack frames. Fox example, to pxov~de a frame of substantial rigidity often requires additional weight in the frame struc~ure.
A fur~her problem relates ~o dynamic forces which are applied to the frame, which place a Atre~ on the frame and on the packer.
These forces are different from the essentially static forces generated by the aforementioned lashing. These additional ~orces are applied to the frame through part3 of the ~uspension system ussd to attach the frame to the packer. Such dynamic force3 vary in both direction and inten~ity with movement o~ the packerls body during walking and brea~hing. Being cycllcal and repetiti~e, - these forces work ~o bend the ~rame repea~edly thus tending to fatigue the metal or other materials used in the frame, ultimately causing structural failure. In frames having welds, holes, ; ~harp bend~ or rigid ~oints, the flexing i~ often concentrated in a way which hastens fatigue, cracking and ailure. Therefore, there has been a need for a frame which i5 capable of supporting a load but ha~ a ~ype o ~igidity which would not be susc¢ptible to the d~truction cau~ed by the~a rep~ti~iva dynamic force~

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A ~urthex ~igni~icant dis~dvan~ag~ re~erred to above, i~ the lo~ o~ energy ~u~'cained hy a backpacker by vir~ue sf the repetitlve generation o~ ~orce whlch is resi~ted by tha . rigid ladder frame. Such energy would pre~érably be conserved fox use in more pleasurable pursuit~. Further, in many cases preRsures are concen~ra~ed on cértain areas of the packer's body causing pain or discomfor~. Also, the cross pieces used in many ladder frames are in position to bear on the packer's back or spine or ~houlders in a way cau~ing di~com~ort.

10BRIEF SU~ RY OF THE I~3VENTION

The backpacker'~ device of thi~ ~nvention overcome the aforementioned problem~. The invention i~ characterized by a unique ~rame structure having a cen~ra~ weight-bearing leg which terminates in a lower oot, and two lateral weight-bearin~ leg~, one on either side of the central leg, each termin-ating in lowex ends and connected to the central leg remote from the lower foot and lower end~ r~rt~r~ r~t~-~h~ frame structure i9 formed of a single bar in a generally ~-~haped con~iguration. The lateral legs of the frame are prefer-ably 1exible. Other preferred embodimen~s include a contouredlatar~l profile ln the frame, a hip belt to which the weight-baaring legs of tha frame are at~ached in a particular relationship, a r~gid belt-reinorcing strap to prevsnt excessiYe lateral movement of the frame lower ends and to help distribute the load around tha back of the packer's hip~, and a packbag secured on the f rame in a particular relationship.

This inventlon i5 based in part on the discovexy or .recognition that ~ignificant rigidlty in a ~rame structure i~
no longer neces3ary, and indeed, that ~uch exces3ive rigidity is unde~irable~ In thi~ inven~ive ~ra~e ~tructure, ~lexing or ~C~7~

banding can be accepted by the weitJht-bearing leys withou~ 3ub-~tantlal re-~istance, because of the configuration of the fr~me.
~namic forces will be distributed over the frame ~tructure, being di~persed so as not to cau~e fatigue ox failure. The frame can be allowed to bend to accommodate body movement.
The three ~u~por~ points provided by -the lower ends of the lateral legs and the lower foot of the cen~ral leg axe no~ rigidly connected generally in ~he upper poxtion of th~ frame. At their lower extremities they are free to undergo a degree of relative lateral movement one with respect to the other~ and may therefore move as needed to accommodate body movement.

The center lift poi~t, or lower foot as lt i3 often referred o her0in, may be attached to a padded section of a hip belt in an area to be near, preferably just below, the polnt where the spine i~ joined to the pelvis. At thls point the lowex foot transmits a ~ubstantial amount of weight to the pelvi.~, preferably tran ferring the weigh~ of the packed load around the back of the pelvic shel Such tran~fer may be ~acilitated by use of a rigid belt-reinforcing strap which extends acros~
the back of the packer's hips.
, The center lift point is very avorably located with relation to the center of gravi~y o~ the packed load, parti-cularly in embodiments of this invention in which the upper portions o~ the aforementioned two ~upport columns are contourad .. : 25 forward toward the packer'~ shoulder~. Since the lower foot lits from a point nearly dlrectly beneath the center of gravity of the load, the backward pulling of the top portion of the ; loaded frams i8 minimized, thereb~ minimizing the forward thrust of the bottom portion of the rame. Further, ~lnce the packed load may b~ centexed almost directly over the central lower oot lift point, the load can nearly be ln balance over thls ~778~
point, thereby requlring a minimum of o~war~ pulling by the pac~er through shoulder straps attached ~o the upper portion o~ the frame structure. This, of course, provi~es more comfort to the packerO

In addition to ~he load~earing ~unction o~ the centrally losated lift point, the lower ~oot there of function~ to hold the lower part of the frame rearward, countering the forward ~hru~t which occur~ a~ the packed load tends to rotate about the central point of lift.

In the frame s~ructure o~ this inven~ion, the two lateral leg~, on either ~ide of the central leg, also have a load-bearing ~unction. These lateral legs have lower end~ which are attached by a flexible connection to a hip beltO Flexibility in the la~eral legs provide~ improved fr~edom o~ body movement ~or the packer and its obvious benefits in a wide variety of acti~ities. The lower ends of ~he lateral le~ are normally flexibly attached to the belt at points forwaxd o~ the centrally located lower foot. The three lift point~, therefore, may be : located acro~ and around the back of the pelvis, and provide a superior load-bearing arrangement.

Certain embodiment~ of the frame of this invention are designed in such a way that two interconnected support col~nns, which ~orm, ~or ex~nple, the two halves of an M-shaped fxame s~ructure, support ~he pack load well up along the packer's back and over the ~houlder area. Th~ not only allows good distribution and equaliziation of pres~ure on the packer's body, but provide~ a conveni~n~ at~achmen~ poin~, at ~he ~ops o~ the ~upport col~nn~, ~or rigid ~houlder brac~. Such braces provide lmproved load ~tability and a spacing between frame and back which i~ advantageous ~rom thé standpoint of com~ortO
The ~houlder braces u~ed in pre~erred er~odiments of thi~ invention -6- .

~C~7789~
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are the subject of ~ conl~lonly owned Canadian ~atent 1,006,135 of Jerry D. Rob~rtson.

No cross members are need~d in ~he r~me structure o~ this inventionr Restriction of head movement or uncomfort-able cross-spine contact cannot be a problem in the frame of this invention. In the preferred.~S-shaped configuration o this invention, four vertical 3ections o~ the "Mn struc~ur~
are locatcd over muscular areas o~ ~he torso rather than bony ~reas, so that a n~inimum of discornfort resul~s frorn body con~act~
Further, curvatur.e of the fr~me forms a concavi~y to correspond generally to the sometLmes convexly curved surface of the human ~ack.

Wi~h the foregoing in mind, it is.the pri~ary object o~ this invention ~ provide a bac~packer's device overcoming ~le aforementioned problems.

Anothex object o~ this invention is to provide a pack frame having only the necessary rigidity and having ~n improved wei~ht-bearing configuration.

Another object of thi~. inverltion is to provide a backpacker's device having improved comfort i.n a wide variety oi bac~pac~r's activities.

Another object of this invent~on i5 to provide a pac~ frarne allowing improved r~edom of movem~nt and reducing or elimlnating loss o energy caused by work ~asted in fl~xins a rigid frame.

Yet ænother object o~ thi.s inven~ion is t~ provide ~ pack ~x~ne o~ ~m~clu~ and si~,ple construction, ha-~ing .lG
welds or otner junct-~re points.

~77~

Stlll another o~ec~ of ~hi~ inventlon is to provide backpacker'~ equipment lncluding a ~rame having a primary suppor~
pPint located closely in line with th~ center o~ gravity of th~ packer' 8 load.

A~other object of this invention i~ to provide back-packer's equipme~t including a frame whlch is designed to transfer we~gh~ to the pac~er' 8 body near the juncture of his spine and p~ltri~ .

Anoth~r ob~ec~ o ~hi~ invention i3 to provide a pack frame which is much les~ susceptible to structural fallure than ~ha well known ladder type frame.

Another object of thi~ invention is to provide back-packer's equipment ~vercoming the aforementioned pro~lem~ which pxovides a high degree of comort to the packer.

l~RIEF DESCRIPTION OF TI~E DRAWINGS

Thsse and o~her objects will be apparent from th~
following description of preferred embodiments and from the drawing~ wherein:

FIGURE 1 is a perspective view o~ a preferred frame structure o~ thi~ ~n~entionO

FIGUR~ 2 is a side elevation of the struc~ure of FIGUR~
1, ~howing its intended position with respect to a packer's backO

FIGURE 3 is a back elev~tion o~ the device in FIGURE

2.

~ IGURE 4 i8 a p~r~pective view of a backpacker'~ devlce aacording to thi~ inventlon.

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PI~URE 5 i~ a 5ide el~vation showing th~ devlce o~
FIGUR~' ~ in posi~ion on a bac~pack~x.

FI~URE 6 is a view of sectlon 6-6 a~ lndicated in FIGURE 3, lncluding, however, only the frame, to illu~trate 5 . th~ bear~ng locations of the thre~ legs.

DETAILED DESCRIPTION OF PREFERRED ~r~BODh~ENTS

~ hroughout the ~igures, like numerals will be used to indicate like parts.

. FIGURE 1 i~ a perspective view of a frame 3tructure 10 which iB formed of a single bar which ha~ an "M" shaped configu-ration. Bar 12 may be made of a ~arie~y of ma~eria~. Pre~erred material~ are hollow aluminum stoc~ or hollow magne~ium aluminum alloy~. Numerou~ light we~ght metals are also preferred materials for use in bar 12. In addition to metal3, other ~ufficiently rigid materials would be ~ntirely acceptable. Bar 12 need not be hollow, but may be a solid rod. Bar 12 has a round cross ; section~ however, other cross-sestional ~hapes are quite acceptableOIn determining materials fox use in b~x 12, consideration may ; be given to weight, strenqth and flexibility. Single bar 12 may be ~ormed into th~ "M" 3haped configuration ~hown by any of a number of methods, including bending, casting and the like.
~ar 12 ha~ no welds or other connections, since it is made from one piece~
.
Frame s~ructure 10 includeR central leg 14 which i~
f~rmed of a central portion of bar 1~ doubled oYer. Central ley 14 terminate~ in a centrally located lower foot 16, which . provide~ the primaxy lift poin~ o~ ~ram~ ~txuc~ure 10. At its : upper end lower oot 16 is connec~ed to two lataral welght-~6377~
bearin~ legs 18, one on either si(le of cent~al ley 14. Indeed, lateral leys 18 and the upper por~ion~ o~ centr~ g 14 are integral. L~teral leg~ 18 term~n~te in lower end~ 20, whlch are generally adjacent to lower ~oot 16 ~uch that both lower ends 20 and lowex foot 16 may be connected to a hip belt as will be expla~ned further herein.

There are no completely rigid conn~ctlon~ bet~een low~r foot 16 and lower ends 20: the legs extend below any such inter-leg connect~on. Lateral legs 18 are connected to central leg 14 at a location remote from lower ~oot 16 and lower ends 20, rendering the lower portions o~ central leg 14 and la~eral legs 18 Pree to ~ome extent to move fore-and-aft and laterally relati~e one to the other. Frame structure 10 has a certain rigidi~y by virtue o~ the rigldi~y of ~ingle bar 12; however, becau~e o~ the ~ree-end construction, the lower portions of the three legs of frame ~tructure 10 are not rigidly ixed ln position one to the o~her but may be flexed to provide con~lderable ~ ~reedom of movement and eliminate los~ of energy cau~ed by exces-sive working against a rigid frame in normal walking motions.
Further, the frame material is such that a degree of "give,"
or flexingj is available within the length of lateral leys 18 themselve~, without regard to the remainder of th~ frame 3~ructure, .

Frame structure 10 forms two ~upport columns 22 which are lnterconnected at lower foot 16. Each of the support column~
22 ext~nd upwaxdly from lower foot 16 and one of the lower ends 20 and terminate in shoulder-adjacent portions 24. In the embodi-ment~ ~hown, ~he support columns are formed of a lateral leg and a portion o~ the cen~ral l~g~ ~owev~r, wl~h okher con3~ructions other structure~ can orm the suppor~ aolumn~.

~.~3778~

As shown best in FIGURES 2 and 5, frame structura 10 i5 conto~red to conform to the pro~ile o~ the human ~ack.
5~houlder adjacen~ portions 24 extend ~orwardly ~rom the general plane defined by ~rame struc~ure 10 and lower ~oot 16 extend8 -- 5 rearwardly therefrom. Such a contoured configuration not only conforms to the profile of the human baok but allows connection of a packbag to frame structure 10 in a posi~ion more nearly directly above the primary support poin~, which iS pxovided by lower foot 16. This is illustrated best by FIGURE 5. Packbag 10. 26 i~ attached to support columns 22 at shoulder-ad~acen~ por~ions ~4. Such attachment may conveniently be accompllshed by the u~e of inverted pockets 28 which are formed on the surface O~
- packbag 26 in po~ition to receive the top~ of ~houlder adjacent portions ~4. Packbag 26 may be further secured to frame 10 at other point~.

A padded hip belt 30, which surrounds the hip~ of a packer Wearing the backpacker'~ device of thi~ invention, i8 used as a bearing area for the three weight-bearing leg~
; of ~rame structure 10 of this invention. Lower foot 16 may ~0 be secured to the central portion~ of hip belt 30 by means of pocket 32 as 8hown ~n FIGU~E 5. Pocket 32, or ~ome other connec-t~on or ~eauxing mean~, assures khat central leg 14 and ~ts lower foot 16 will remain in a laterally fixed position with xe~pect to the packer'~ hip~, namely, at a posit~on ~u~t below the ~uncture of ~he packer'~ ~pine and pelvi~. Lower foot 16 : may be free to pivot in pocket 32, about a fore-and-aft axl~, t~ accommodate certain body mo~ements.

Lower end~ 20 o~ lateral leg~ 1.8 are ~oined to hip belt 30 at lateral po~ition~ by ~lexlble connec-ting mean~ 33, whlch include, ring~ 31 a~ached ~o lower end~ 20, ~txap~ 3~, and D-rings 37 whiah are 3ewn to belt 30. Each leg 18 passes ' through D-rirlg 37 but retains sub~t~ial ~r~odom o~ moveMent.
Connec~iny ~eans 33 are of sufficient length to accommodate variou~ body moveinenks o~ the packex without placing an undu~
str~in on ~r~ne 10. For example, in a forward bending motion, -- 5 lower ends 20 of lateral legs 18 will tend to separ2te ~rom hip belt 30. Connecting mean~ 33 are of su~iCient length to accommodate such body movementq A belt-rein~orcing ~trap 35, made of me~al or some other rigid material, i~ ~ewn in a pocke~ o~ hip belt 30 posi-tioning it acros~ the back of th~ packer' 8 hips and extending across the width of ~rame 5tructure lO, Strap 35 may be u~ed to prevent excessive squeezing together of lower end~ 20, such as can tend to occur with very heavy loads. However, strap 35 does not inter~ere with the ~reedom of movement o~ lateral c leg3 l~ provided by this invention.

As illus~rated best in FIGURES 2, 5 and 6, lower ends 20 are in a position ~orward of the position of lower ~oot 16. This arrangement tends to distribute the ~eight around hip-engaging belt 30.

As shown in FIGURE~ 4 and 5, substantially rigid bra~e members 36 are coupled to shoulder-adjacent portions 24 of ~rame s~ruc~uxe lO and axtend from frame struc~ure lO
to terminate in free ends 28 which axe generally aligned with shoulder-engaging portions 40 o~ shoulder straps 42. Brace 2~ members 36 are made of rigid or semi-rigid material such that they have sub~tantially ~ixed dimensions between ~houlder-engaging portions 24 a~d fxee ends 3~. Free end~ 38 are conneated by ~lexible connectors 3~ to the convex upper ~urface~ ~6 of shoulder-12~

7f3~ ~
engayiny ~ortions ~0. Shoulder stxa~s ~2 have ir~t ends 48 which are connected to fx~e ~tructure 10 near lower end3 20 and second ends 50 which are secured wltll respect to frame ~tructure lO at a le~el below shoul~er-engaglng portion~ 40, S through strap 52 which extends from lower foot 16 upward1y to a lide loop 54. Second ends 50 of sho~lder straps 42 axe joined one ~o the o~her through ~ e loop 54 ~o allow for relative lengthening and shortening of shoulder straps 32 to accommodate various ~odily movements.

The arrangement of ~houlder s~raps and brA ce members used in the preferred embodiments of this invention provide add~d stabili~y to the load being carxied and also prov~de ~pacing between frame stxucture 10 and the back of the packer~
Such spacing is desirable ~o eliminate the discom~ort~ of repetitive contact of back with ~rame and to provide the advan-: tag~ of ventilation between back and load.

A wide variety of frame ~tructures may be designedln accordance with this invention. While a single ~ar ls highly preferred for both ease of construction and comfort, othax configurations cons~ruc~ed ~rom more than one piece are within the ~cope of this in~ention and can be used to : obtain the advantage~ of this invention. Alt~rnativs configura-~ions and constructions within the scope o~ this invention will be obvious to those skilled in the art to whom this invention has been disclosed. The term "frame", a3 used herein, re~ers to a device having some rigidity used for mounting a pack bag. The term neither requires nor im~lies any ~peciflc shape, form or material.

Material~ which may be u~ed ln produaing the various COI~pOnentQ o~ the backpacker's device of thi~ invention will ' ' ' .
~ J

~7~8~a ~e obvious to those ski].led in the a~ to ~hom ~his invention ha~ been disclosed. In most ca~es, such ma~erials will be a matter of choice or convenience.

While in the foregoing specification thi~ invention ha~ been de~cribed'in xelation to cer~ain preferred embodiments~
and many detail3 have been 5~t forth for purpo~e of lllustration~
it will be apparent to those skilled in the art that the inven-tion i~ su~ceptible to additional embodimen~s and that certain of the details described herein can be varied con~idexably without departing rom the ba~ic principle~ of the invention.

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Claims (6)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A backpacker's device comprising:
a frame structure having a central weight-bearing leg terminating in a lower foot, and two substantially flexible lateral weight-bearing legs, one on either side of said central leg, said lateral legs terminating in lower ends and connected to said central leg remote from said lower foot and lower ends whereby said lower foot and lower ends have relative freedom of movement, said frame structure forming interconnected support columns extending upwardly from said lower foot and lower ends and terminating in shoulder-adjacent portions and generally conforming to the profile of the human back, wherein said frame structure is formed by a single bar substantially in an M-shaped configuration and said central leg comprises a central portion of said bar doubled over.

2. The device of claim 1 wherein said shoulder-adjacent portions extend forwardly and said lower foot extends rear-wardly.

3. The device of claim 1 further comprising a hip-engaging belt, said lower foot secured thereto in position to be adjacent the juncture of a backpacker's spine and pelvis and connectors flexible joining said belt and said lower ends of said lateral legs.

4. The device of claim 1 further comprising:
flexible shoulder straps adjacent to said frame structure between said lateral legs, said straps having concavo-convex shoulder-engaging portions and having first ends attached of said frame structure near said lower ends of said lateral legs and second ends secured with respect to said frame structure at a level below said shoulder-engaging portions; sub-stantially rigid brace members coupled to said shoulder-adjacent portions of each of said support columns, said brace members extending from said frame structure and terminating in free ends generally aligned with said shoulder-engaging portions of said shoulder straps, said brace member being of substantially fixed dimensions between said shoulder-adjacent portions and said free ends; and means connecting said free ends of said brace members with the convex surfaces of said shoulder-engaging portions of said straps.

5. The device of claim 3 further including a rigid belt-reinforcing strap within said belt in position to extend across the back of the packer's hips.

6. The device of claim 4 further including a pack bag attached to said frame structure at said shoulder-adjacent portions.