CA1044197A - Backpack frame having shoulder and hip supports with flexible connection to hip support - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The frame to which a backpack is fastened is formed of tubing bent in hourglass shape in rear elevation and two inward offsets in side elevation. A horizontal rigidifying cross bar extends through about the middle of the top part of the hourglass and is adjustable at different elevations. The upper end of a connector is fixed to the narrow part of the frame at adjustable elevations. The lower end of the connector is fixed to a hip level belt stretcher. The connector is constructed with gener-ally vertical ribs which are wide in a front-rear sense and thin in side-to-side sense so that the connector flexes about the Y
and Z axes passing through the narrowest part of the connector, which is positioned close to the point of the spine of the wearer, where there is little or no bending of the spine during bending or twisting of the torso, but is rigid against flexing about the X axis. A hip belt encircling the hips of the wearer is con nected to the belt stretcher at the lower end of the connector.
The tops of shoulder straps are adjustably connected to the cross bar and the lower ends to the lower part of the frame. The pack weight is distributed between shoulders and hips. Natural move-ments of shoulders and hips are not inhibited.

Description

This invention relates to a new and improved backpack frame having shoulder and hip supports with a flexible connection be-; tween the frame and the hip support. The fr~me and its supports permit the user to carry heavy load~ but allow freedom of normal bod~ movement. Thus the pre~ent invention permits relative move-ment between the shoulders and upper back of the wearer o~ one hand and between the upper back and the hips Or the wearer on the other hand.
The frame of the present invention is secured to the shoulders of the wearer by shoulder straps and is conne¢ted by mean~ of a connector to a hip beltc The connector permits flex-ible movement about two but not thres axe~ which coincide at a locus at the spine which has least bending as the wearer moves his torso with normal bsnding or twisting movemeDt~ Thus9 ~-although freedom of movemsnt is permittbd, nevertheless, the f`rame does not have a forward~backward movemsnt and the connector does not flex about a horizontal tranS~erse axis through said lo cus l, , ' The ~act th~t the present invention permits relative move-ment between the shoulders and upper back and hips of the wearerraduces fatigue from carr~ing heavy loads.
Another ~eature of ths invention is that a part of the weig~ht o~ the paok i~ carried by the shoulder~ and a part b~
the hips, again reducing fatigua.
Th~frame of the present invention i~ relatively non-flex-ible~and i~ formed of tubing bent in a generally hourglass shape with a cross bar at or slightly above the shoulder level. The hourglas~s shape permits the elbows to swing ~reely without con-tacting the frame and eliminates some of the cross bars of con~

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ventional pack ~rame3,rthereby reducing the weight of the frame.

Another feature of the in~ention i~ the adjustability of .. .
the frame. Thus the connector bet~Jeen the frame and the hip belt ' . ', ' . ~ .' ' ' ' ' ~ , .

may be moved vertically upward and downwardO Similarly, the cross bar to which the upper ends of the shoulder straps are attached may be moved vertically upward-downward. Further, the point of attachment of the upper end of the shoulder straps ma~
be moved horizontally inwardly and outwardly These features of adjustability permit adjustment for the size of the wearer and particularly the distance between the shoulders and hips~ Further, the invention per~its adjustment of the center of gravit~ of the pack relative to the center of gravity of the wearer. The latter ad~ustment is important where the terrain varie~. Thus, the pack may be carried high or low on the back as desirsd for com~ort and ~tability.
A further reature of the invention is the construotion of a connector between the metal portion of the ~rame and the hip belt~ At its narrowest point, said connector compri~es inwardly ~ ~
curved substantially vertical forward-rearward extending ~ide ~-walls which are considerably thinner than their forward-rearward dimension and preferably there is a gap between said side walls and a vertical straight inner wall. Between the side walls and the inner waLl are soft elastic cores which separate the parti-tions but make it possible ~cr the partitionq to flex. The nar-rowest portion of the connector at the midpoint of the thickness :j ` :
thereo~ is the location whare a horizontal transverse X axis, a vertical Y axis and a horizo~tal longitudinal Z a~is intersect.
As has previou~ly been mentioned, when the pack is on the rrame and the~rame is strapped to the body the axis-intersection point . ~ , of the connector i5 c10901~ adjacent to the point of the spine which does not flex despite bending and twisting movements of the shoulders relative to the hipo The connector permits flexure ~30 about the Y and Z axes, the soft elastic core allowing the thin-wall webs to move relative to each other while preventing a total ~ -collapse of said thin-wall webs and maintaining a geometr~ which ~ -: '!~
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. , , is generally similar to the connector at rest. Further, the connector has the ability to withs-tand substantial compressive loads without buckling. The soft elastic core functions as a support or restraining force which aids in maintaining the orig~
inal geometry o~ the thin-wall webs even lf the loading is Orr center, Another feature of the construction o~ the connector i~
its ability to resist any rotation about the X axis. This results ~rom a combination of the relationship of the thinness of the ribs to their ~ront-rear dimension and the effect Or the soft ela~tic core acting to retain the original geometry o~ the thin-walled members. -~
Another feature of the invention is the construction o~ the belt stretcher which is either integral with or connected to the connector. Said stretcher is concave and is su~iciently flexible 90 that lt places the hip-engaging belt under continuous tension but accommodates the shape o~ the back of the wearer when the hip-engaging belt is tightened. The beLt i5 attached to the outer ends , of the strebcher and encircles the torso near the hips. The belt i9 padded for comfort. The stretcher does not engage the wearer's ' 20 ba¢k.
`i Other objects of the present invention will become apparent ~` upon reading the following specification and rsrerring to the accompan~ing drawings in which similar characters of rererence -represent corre~ponding part3 in each of the several views. ;;~
In the drawings~ ;
Flg. 1 is a 3ide elevational view o~ the frame.
: Fig. 2 i9 a ~ront elevational view thereof.
Fig. 3 iq a fragmentary sectional view taken substantially , ~ along the line 3--3 of Fig. 2.
~30 Fig~ 4 i9 a sche~atic perspective view showing the three axes passing through the nodal point of the connector.
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Fig. 5 is a side elevational ~iew in reduced scale showing ,~ -the frame and a pack attached thereto in position of wear.
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Fig. 6 is an enlarged front elevational view of the connec-tor and its plate~
F;g. 7 is a vertical sectional view taken substantially along the line 7~-7 of Fig. 6.
Fig. 8 is a view similar to ~ig. 6 of a modi~ied connector.
Fig, 9 is a sectional view taken ~ubstantially along the line 9--9 of Fig. 8.
~- Fig. lO i9 a front elevational view of a modified plate which may be used with the structure either o~ Fig. 6 or Fi~. 8.
Fig. ll is a fragmentary sectional view taken sub~tantially ` along the line ll~-ll o~ ~ig. 2.
Figo 12 is 8 somewhat schematic top plan view ~howing the belt stretcher and beltO
~ The present invention employs a rigid rrame 2L formed of ,~ metal tubing and preferably having a single joint 25 and having an hourglass shape when viewed in ~ront or rear elevation. A pack `, 22 which may be o~ any shape i~ connected to the frame 21 by means not shown and sub~ect to considerable variation. The tubing which forms the rrame 21 ha~ a top horizontal member 23 which in the inatalled position of Fig. 5 is preferably behind the back oi~ the head and is forw~rdly curved and bent in relatively large radius 90 ¢urves 24 which join the top vertical sides 26 e~tending down to about the point where the back and shouldars of the wearer join.
Below the top verticaI stretches 26 are inwardly-rearwardly angled ~ -stretches 27 which terminate in sub~tantially vertical waist sec- ,~
.-~ .. , tIons 280 At the lower end of sections 28 are outwardly-rearwardly cur~ed stretche~ 29 which terminate in bottom bends 31 which are co~nected together by bottom horizontal member 32 in the middle which i9 the joint 25. Observing Fig. 1, it will be seen that the top horizontal member 23 is orfs3t rearwardly relative to top ~ vertical stretches 26 and that the vertical waist sections 28 are ; offset rearwardly relative to stretches 26. Bottom bend~ and horizontal member 32 likewise are offset rearwardly. As is best ~, . ,; ~ . . . - : .: ' , ,. ~ . :
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shown in ~ig. 5~ the shape heretofore de~cribed insures that the lower portion of the ~rame 21 is o~set suff~iciently rearwardly to accommodate the hips o~ the wearer and to permit easy strides.
The narrow waist of the hourglass ~rame permits the elbows of the wearer to swing rreely without contacting the frame.
To rigidi~y ~rame 21 and aLso to provide a mean~ o~ attach-ment to the straps and webbing ais hereinaf'ter set forth, a horl-zontal transverse top cross bar 36 is provided which attaches to ; one o~ a vertically spaced apart series o~ holes 37 ~ormed in top ;~ 10 vertical stretch 26 and is held in place by an attachment 38 Thus the cross bar (and the top atkachment for the ~houlder ~trap) may be adjusted vertically depending upon the height of the wearerO
Bottom cross bar 39 extends bstween stretche~ 2~ and is preferably ~ixed in position~
Upper shoulder strap 41 is ~astened to top cross bar 36 and - ;
;~ ~or such purpose the latter lS provided with a plurality o~ hori-;~ zontally ~paoed apart holes 44 to which said upper shoulder ~trap 41 i9 attaohed by abtachment means 46. Lower ~houlder strap por-tion 42 is connected to upper portion 41 by an ad~u~table buckle 43 ao that the length o~ the ~traps 41, 42 may be ad~usted ~or the 8izr 0~ the wearer. Lower shoulder strap 42 is attached to por~
~`~ tion 29 a~d~acent their outer and. As sho~7n in Fig~ 5, tha shoulder~strap e~tends from top cro~s bar 36 up to the top of the shoulders Or the wearerJ rorwardlyg under the arms and outwardly rearwardly to the point o~ attachment 47. Thus a portion of the weighb o~ tha~pack 22 ma~ be carriad by the shoulders o~ the ,:: : : : , . .
~ wearsr. 7,~
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Horizontal transverse webbing 51 extends around and between the lower ends of top vertical stretches 26 and applies part Or ~30 the weight o~ the pack to the back o~ the shoulder~ and upper back ~;
o~ the~wearer. Webbing 51 is hald in place by attach~ents 52 ~ ;
~` threaded into the tubing o~ the frame or lashed to the tubing o~
i~ ~ the frama. Extending vertically batwean kop cross bar 36 and ~ , ~:
bottom cross bar 39 is ~ertical webbing 53 which holds the pack 22 rearward of` the ~rame 21.
An important ~eature of the invention is the construction of connector 56 which transmits part of the weight carried by the ~rame 21 downward to the hips of the wearer. In the form Or the invention shown in Figs. 1-6, connector 56 has a top transver~e member 57 which extend3 between the stretches 28 and assi~ts in spacing them apartr The forward-rearward horizontal dimension o~
member 57, as well as the other members Or the connector 56 here-ina~ter described~ comprises what is termed herein the "thickness"
of member 57 as distinguished from the wall thickne~s thereor.
Below top 57 are sides 58 ~ormed as cylindrical sections to engage the tubing of' stretches 28 and below the clamp portions 58 are con~
cave sides 59 which terminate in vertical downward extensions 61 . i : connected to bottom belt stretcher 62, hereina~ter described~ The borizontal transverse pin 63 has its head 6l~ on the outside of` one outer clamp member 67 which li.kewise is a section of a cylinder and , ~ - .
:~ rits again3t the outside Or tubing 28 opposite inner clamp member ~:
~ 58. On the side of` connector 56 opposite head 64 the pin ~3 is ~ ~-" , . 20 threaded and provided with a nut 66 which bears against the clamp member 67 on the opposite side of the ~rame. As is be3t shown in ~ Fi~. 3, the clamp structure hereto~ore described insures that the ,~ connector 56 at its uppar end i3 rigid relative to~r~me mambers 28. Pin 63 f`its through any Or vertically space~ apart holes 68 ~; : in stretches 28. This permits vertical adjustment of the upper ; ~ ~
t~ ~ end of connector 56 depending partially on the size Or the wearer and partiall~ on the desired weight distribution.
Re~erring now to Figs. 6 and 7, the ~ides 59 are thin in wall thickne-ss relative to their total thickness and midway between the ~ .
concave sides 59 is a vertical center rib 71 which likewise is thin in wall thicknes~. The spaces between top tran3verse rib 72 and bottom transverse rib 73 which def`ine the narrow waist Or the con-nector 56 are filled with so~t rubber or an elastomeric plastic 74.
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~`'''. ' ,: :. .' " : - ' , The rubber ~illing 74 permits flexure of connector 56 about the Y and Z axes as defined in Fig, 4 with axis intersection point 76 being located at the narrow waist of the connector approximately midway of the thickness of rib 71. Flexure about the Y axis per-mits one end of the stretcher 62 to move forwardly while the other end of the stretcher 62 moves rearwardly. Flexure about the Z
axis permits the stretcher 62 to ~ove from the solid line position of Fig. 6 to the dot and-dash position and a combination of the movements about the Y and Z axes permit~ a simultaneou~ twisting and bending o~ the narrow waist of the connector 56 about the axis intersection point 76~ The rubber rilling 74 permits the narrow ribs and ~ides to bend without collapsing and r~stores the walls to initial position when the bending stre~se~ are relaxed. Flex-ure about the X axis iq prevented by the construction of the connector 56 in that the wall thicknesses are quite thin but the overall thickness from ~ront to rear is considerably greater, and hence bending is restrained.
Str~toher 62 in the form o~ the invention shown in Figs. 1-9 is generally trapezoidal with rounded outer corner wingq 83. Thus the width as viewed in Fig. 2 of the upper end of member 62 is .
narrow~ angling downwardl~-outwardly from the lower end of connec-tor 56 and the bottom edge of member 62 i~ aubstantiall~ hori ,,;,-zontal~ The stretcher 62 is rigidified by means of vertical central~rib= 78 and the stretcher 62 is further rigidified by peripheraL ribs 79~ The back 81 of ~tretcher 62 slants forwardly~
downwardly. Attachment holes 82 are ~ormed near the outer ends of ~;
the outer wing~ 83 o~ the stretcher.
The hip belt consists Or a padded back portion 86 which is substantiall~ rectangular in shape and is attached to the holes 82 by~atta¢hment means 81~. Although the ribs 78, 79 rigidify =tretcher 62, neverthelessJ the plate ~ay flex to apply ten3ion -to belt portion 86 to keep the belt taut and keep stretcher 62 i away from the back of the wearer. (See especially Fig. 12). ~ -; : :.
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-~ Attached to either end of back portion 86 are straps 87 which ~; come around the torso of the wearer and are prererably joined to-gether by a front buckle 88. Thus a portion o~ the weight of the pack 22 is transmitted by the connector 56 down to the belt and on to the hips.
In the ~orm of the invention, as shown in Fig. 6 and 7, -the upper portion of connector 56 and the stretcher 62 are integral and are preferabl~ molded Or a plastic material such as nylon.
Instead of the trapezoidal shape o~ the stretch b2 o~ Fig.
6~ a rectangular strstch 62b as shown in Fig. 10 may be substi-tuted. ~nobs 91 may be ~ormed at each corner o~ stretcher 62b to assist in locating the back o~ the belt relative to the stretcher.
Although not shown in Fig. 10~ the stretcher 62b may be thicker and only su~ficiently flexible to permit the belt to accommodate the curvature of the back of the wearer.
In the ~or~ of the invention shown in Fi8~ 8 and 9, the upper ` ~
portion of the connector 56a is ~ormed o~ metal and is separate - ~ -~rom the stretcher 62a but rigidly secured thereto. Two top eyes ;
; 96 are formed in connector 56a by multiple bends of the metal strap of which they are comprised. Thus, each eye 96 has a top 57a, a vertical downward central stretch ~7J an outward bent stretch 98, which i9 formed with an outward-upward bend 99 which matches the bend 99 o~ the inner clamp member 58a which depends from top 57a. ~ -~ ~ The upper end of center rib 71a i~ sandwiched between the vertical q~ ~ stretohes 97 and the upper ends of outer ribs 59a are sandwiched between the bends 99.
; The~concave sides 59a, gripped between the bent portions 99 o~ the upper eye 96, curve inwardly and outwardly in concave shape, their narrowffst point being at the Z axis of the axis-crossing ~ point 76a. Between the concave sides 59a is cen-ter rib 71a and the sides 59a are filled with rubber or plastic material 7 ~ , all .~ , .
; a~ in the preceding modification. Stretches 98 rorm the top boun-, . .
darie~ ~or material 74a and portions 102 of bottom eyes 101 the ' ~' ~ : . .. .... .
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:~3~ 7 bottom boundaries therefor.
Below the central portion of connector 56a are bottom eyes - 101 each having a top 102 which forms a boundar~ for the lower end o~ the plastic material 74aO Top 102 i5 bent upwardly-downwardly at its outer edge in an outward bend 103 and at the oppo~ite edge of top 102 is bent inwardly ancl downwardly in an inward bend 101~.
Below bend L04 the lower eye slants outwardly~downwardly in a stretch 106. The lower edges of concave sides 59a are gripped between outward bend 103 and vertical outer brace 107. The lower 10 end of center rib 71a is gripped between the opposed inward bends 104 of the two eyes 101.
Stretcher 62a, as shown in Fig. 8, is an elongated diamond shape. Xowever, it wiLl be understood that the shape may be similar to the outline of members 62 of Fig. 6 and 62b of Fig.
~ 10. The upper edge oE stretcher 62a is rigidified by peripheral ; rib 116 pro~scting rearwardly o~ the top edga of stretcher 62a.
A U-shaped bracket 111 is attached to the back o~ the center ;`-~
of stretcher 62a by rivets 112 or other means. The lower ends of outer braces 107 overlap the parallel flanges 114 of bracket 111 20 and are connected thereto by rivets 113.
The connector 56a of Figs. 8 and 9 resembles in ~unction the connector 56 of the preceding modification but is ~abricated of~
me;tal aad/or plastio rather than being molded of plastic. In ;~
other respect:, the modification of Fig. 8 and 9 resemblss that of tho preceding modification and the same reference numerals ~ollowed by the subscript a are used to designate corresponding : ~-~ parts.

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Claims (15)

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

1. A backpack frame comprising a rigid member of extended length adapted to extend along the back of the wearer having an upper portion, a middle portion below said upper portion, and a lower portion below said middle portion, said middle portion, gen-erally fitting between the shoulder blades and the waist of the wearer, a pair of shoulder straps, each said shoulder strap having an upper end and a lower end, upper end fastening means to attach each said upper end to said upper portion, lower end fastening means to attach each said lower end to said lower portion, a hip engaging belt to encircle the hips of the wearer, and a connector, said connector being vertically elongated, first means rigidly connecting the upper end of said connector to said middle portion, second means attaching the lower end of said connector to said belt, said connector having third means on its upper end adapted for cooperative engagement with said first means, a narrow portion below said third means, a horizontally elongated stretcher below said narrow portion shaped to fit behind the hips of the wearer and having fourth means for cooperative engagement with said second means, said stretcher being rigid relative to said narrow portion but resilient about a vertical axis to apply tension to said hip engaging means to maintain said stretcher out of contact with the back of the wearer, said narrow portion having at least two gen-erally vertically extending ribs, said ribs being thin in a hori-zontal-transverse direction and being wide in a horizontal-longi-tudinal direction, whereby said narrow portion can flex about a vertical axis and also about a horizontal-longitudinal axis but resists rotation about a horizontal-transverse axis so that said stretcher does not move toward and away from the wearer in a horizontal-longitudinal direction.

2. A frame according to claim 1 in which said narrow ribs are arcuate in front elevation, curving inward toward each other to a narrowest area through which said horizontal longitudinal axis passes, said ribs being separated from each other at said narrowest area.

3. A frame according to claim 2 in which the space between said narrow ribs is substantially filled with a soft elastomeric substance which, under stress, biases said ribs to initial arcuate position.

4. A frame according to claim 3 which further comprises a vertical thin rib bisecting the space between said first-mentioned ribs, said elastomeric substance being divided on either side of said vertical rib.

5. A frame according to claim 1 in which said stretcher is wider in a vertical direction at the center than at either end and in side elevation slants downward-rearward.

6. A frame according to claim 1 in which said stretcher is molded integral with upper and narrow portions of said connector.

7. A frame according to claim 6 in which said second and fourth means are located near the outer horizontal extremities of said stretcher.

8. A frame according to claim 1 in which said first means comprises a horizontal-transverse pin through said upper end of said connector and said third means comprises clamp means to re-strain rotation of said connector about the axis of said pin.

9. A frame according to claim 8 in which said middle portion of said frame is formed with a series of aligned vertically spaced apart holes each adapted to receive said pin to adjust the eleva-tion of said connector relative to said frame.

10. A backpack frame comprising an upper, middle and lower portion, said middle portion being of substantially lesser width measured in a horizontal-transverse direction than said upper por-tion and than said lower portion, so that in front elevation said frame has an hourglass shape, said middle portion being at about the level of the elbows of the wearer when the frame is worn by the user so as to eliminate interference of said frame with arm move-ment of the wearer, and a substantially vertical flexible connector attached at its upper end to said middle portion and having means at its lower end for attachment of said lower end to a belt around the waist of a wearer.

11. A backpack frame according to claim 10 in which in side elevation said middle portion is displaced rearward of said upper portion and said lower portion is displaced rearward of said middle portion.

12. A backpack frame according to claim 10 in which said frame comprises a single piece of tubing bent to form said upper, middle and lower portions with a single joint.

13. A backpack frame according to claim 1 in which said upper portion is provided with a horizontal-transverse crossbar, said upper end fastening means for said shoulder straps being connected to said crossbar.

14. A backpack frame according to claim 13 in which the elevation of said crossbar relative to said upper portion is adjustable.

15. A backpack frame according to claim 13 in which said upper end fastening means are horizontally adjustable along said crossbar.