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Publication numberUS3563431 A
Publication typeGrant
Publication dateFeb 16, 1971
Filing dateNov 6, 1968
Priority dateNov 6, 1968
Publication numberUS 3563431 A, US 3563431A, US-A-3563431, US3563431 A, US3563431A
InventorsPletz Murray J
Original AssigneePletz Murray J
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 3563431 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent [72] lnventor Murray J- 3,106,323 /1963 Davis 224/(.1) 5227 Pleasure Point Lane, Bellevue, Wash- 3,219,243 11/1965 Mack 224/25 .1 x 98004 3,223,300 12/1965 Moore et a1. 224/9X [21] Appl. No. 773,912 3,225,985 12/1965 Romney 224/25(.1) [22] Filed Nov. 6, 1968 3,282,483 11/1966 Babcock... 224/25(.1) Patented b-16, 3,355,075 11/1967 Dean 224/25(.1) 3,367,547 2/1968 Abert et al.... 224/25(.l) 3,442,427 5/1969 Arnellet al.....- 224/25 .1 54] SELF ADJUSTING PACKFRAME 1 5 Claims, 6 Drawing Figs Primary ExammerGerald M. Forlenza Assistant Examiner-Frank E. Werner Cl I Anomfihseed, Berry and Dowrey Field of Search 224/6, 25, I

2 1 1 ABSTRACT; A packframe for hikers is constructed using side and cross-members rigidly held together by tension created in 1 References CIM straps wrapped around the frame. The packframe has UNITED STATES PATENTS shoulder straps anchored at both ends to substantially a coml,586,058 5/1926 Winfield 224/8 Point near the bottom and out from the general load 2,456,253 12/ 1948 Bushey 224/25 (.1 bearing area of the packframe. A belt is coupled near the bot- 2,322,117 95 Mack 224/8 tom of the packframe to absorb a portion of the load and to 2,836,334 5/ 1958 Davis 224/9X H Stabilize th pa kframe.

1 1 3 2| l2 1 t l 25 5 5 s j 7 l8 1e PATENTEU FEB 1 6 I97! sum 1 or 2 FIG I MURRAY J. PLETZ INVENTOR ATTORNE YS PATENTEUFEBIBIHTI 35534 1 xmramz MURRAY J. PLE

INVENT ATTORNEYS SELF ADJUSTING PACKFRAME 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. I

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. I 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 cross bar. The straps in turn tend to rotate the bottom of the base outwardly so as to position the load at the top I 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 l 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 l4, 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 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 l2 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 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 v cinches 19. The structural strength of the packframe is thereby increased. The pads 14 form part of the shoulder straps and contribute to the users 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 users 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 nowpreferred 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.


l. 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.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3730407 *Jul 23, 1971May 1, 1973Russell WCombination pack and cot
US3733017 *Mar 22, 1971May 15, 1973K2 CorpAdjustable pack frame
US3734366 *Feb 11, 1972May 22, 1973Wood TPack frame
US3860157 *Jul 31, 1972Jan 14, 1975Douglas E HallBack pack and frame
US3881644 *Feb 14, 1974May 6, 1975Demaline Donald RConvertible and collapsible backpack
US3897894 *Jan 14, 1974Aug 5, 1975Browning Arms CoPack frame top bracket
US4009809 *May 5, 1975Mar 1, 1977Morris Manufacturing CompanyBack-pack frame
US4087031 *Oct 6, 1975May 2, 1978Fenner Peter MBackpacking frame
US4214685 *Jul 27, 1977Jul 29, 1980K-2 CorporationBackpack load carrying system for hikers
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US4361259 *Jan 21, 1981Nov 30, 1982Pathfinder Camping Products LimitedWire back pack frame
US4561578 *Oct 17, 1984Dec 31, 1985Bell Michael SBackpack for hikers
US5779121 *Apr 16, 1996Jul 14, 1998Johnson Worldwide Associates, Inc.Pocket closure and compression strap for a pack
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US5904282 *Jul 11, 1997May 18, 1999K-2 CorporationExternal frame backpack harness
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WO1999002067A1 *Jul 10, 1998Jan 21, 1999Dana W GleasonExternal frame backpack harness
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U.S. Classification224/262, 224/263
International ClassificationA45F3/08, A45F3/04
Cooperative ClassificationA45F3/08
European ClassificationA45F3/08
Legal Events
May 23, 1983AS06Security interest
Owner name: FIRST BANK (N.A.)
Effective date: 19830301
Owner name: JANSPORT CORP.
May 23, 1983ASAssignment
Owner name: FIRST BANK (N.A.)
Effective date: 19830301
May 24, 1982AS06Security interest
Owner name: DOWNERS, INC.
Effective date: 19820421
May 24, 1982ASAssignment
Effective date: 19820421
Apr 30, 1982ASAssignment
Effective date: 19820422
Apr 30, 1982AS02Assignment of assignor's interest
Effective date: 19820422