CA2181998C

CA2181998C - Cushioning member for an article of footwear

Info

Publication number: CA2181998C
Application number: CA002181998A
Authority: CA
Inventors: Paul E. Litchfield; Steven F. Smith; Matthew Montross
Original assignee: Reebok International Ltd
Current assignee: Reebok International Ltd
Priority date: 1994-01-26
Filing date: 1994-01-26
Publication date: 2003-05-13
Anticipated expiration: 2014-01-26
Also published as: WO1995020332A1; EP0699035A4; EP0699035A1; CA2181998A1; AU6128194A; AU687382B2; EP0699035B1; DE69424044T2; JP3040169B2; DE69424044D1; ES2147782T3; JPH09508288A

Abstract

A cushioning member (10) for an article of footwear is provided having a ser ies of interconnected chambers (26 and 42) filled with ambient or slightly pressurized air. Impedance means (74) is provided betwee n selected chambers, in order to restrict the flow of ai r between the chambers (26 and 42). The shape and structure of the impedance means (74 ) determines the nature of the air flow between chambers (26 and 42), such that the cushioning member (10) can be tailored for variou s types of activities and body weights, by offering vary ing degrees of cushioning.

Description

W0 95/2033~ 2 1 8 1 9 ~t 8 PCrlUS94/008ss o ~ ; r n;n~ ~ember for an ~rticle of Fo~l -.
s~ckgrou~Ld of the Tnvention 1. Field of the I3vention This invention relates generally to footwear, and more partic~lArly to an article of footwear having a c~qh;nn;nrJ me~er ~;crn~ therein which provides ~nh:~nretl r-lch;r,n;n~ properties to the article of f ~ .

2. r ~- ~,m cf l~lat~d l~rt One of the problOE ~Rqor;:~te~ with shoes ha always beerl striki~ a balance between support a3d c~ch;r~ U~J~ the course of an average day, the feet alld legs of an individual are suhjected to ,~,.l,"l _. l ;;~l impact forces. Running, jumping, walking ~nd even 8t:~n~1;n~ exert forces upon the feet and legs of an individual which can lead to 2:~ULel~3~:, fatigue, and injury.
The human foot is a comple~c and l~ h~e piece of r-rh;nl~ry, capable of w;thct~nrl;~ and ~l;ce;rzlt;n~
many impact forces. The natural padding of fat at the heel a~d fuL~=fuuL, as well as the fl~r;h;l;ty of the arch, help to cushion the _oot. An athlete' 8 stride i9 partly the re8ult of energy which is stored in the f 1~; hl - tissues of the f oot . ~or example, during a typical walking or running stride, the achilles tendon and the arch 8tretch and r~ntr~rt, storing energy in the tendons and ligaments. When the rf~ct~ict;ve ~L~U t: on these ~1 c is released, the stored e3ergy is al80 relea8ed, thereby reducing the hurden which must be assumed by the muscles.

WO9ft/20332 2 1 8 1 998 PCT/US94/00895 Although the hu~an foot possesses natural cllqhinn;n~ and rebounding rhArACtF'riStiCS, the foot alone is inrArAhle of effectively UV~L~_ ng many of the forces encountered during athletic activity.
Unless an individual is wearing shoes which provide proper rllqhinn;ng and support, the soreness and fatigue associated with athletic activity is more acute, and its onset accelerated. This results in discomfort for the wearer which ~iim;n; qh~ the incentive for further Athle~;r activity. Equally ;, L~L, inadequately n~lRh;nn~ footwear can lead to injuries such as blisters, muscle, tendon and ligament damage, and bone stress fractures. T, ~,~eI footwear can also lead to other A;l ' q, ;nrl71-~i;nrJ back pain.
Proper footwear should ~ 1 ~ the natural fllnrt;nnAl;ty of the foot, in part by in~uL~ t;nr~ a sole (typically, an out801,e, midsole and insole) which absorbs shocks. Eowever, the sole should also - possess enough rPq;l;~nry to prevent the sole from being ~mushy" or l'~nllArl::;nr;,n therebyunduly-lrA;n;ng the energy of the wearer.
~ light of the above, ~,u~ Att, ,q have been made over the years to incorporate means into a shoe which provides;, .~vt:d ml qh; nn ; ng and r-~q ; 1 ; .on~-y to the shoe. For example, attempts have been made to eDhance the natural elasticity and energy return of the foot by providing shoes with soles which store energy durlng compression and return e~ergy duri~g ~YrAnq;nn. These attempts have tnrlllt~ uging such as ethyleDe vinyl acetate (EVA) or polyurethane (PU) to form m; tqnl~q. However, foam_ such as EVA tend to break down over time, thereby losing their resiliency.

W095/20332 2 1 8 1 998 ~ g' Another concept practiced in the f ootwear industry to improve cushioning and energy return has been the use of fluid-filled devices within shoes The }~asic concept of QnhAnri n~ cushioning and energy return by transferring a pressurized fluid between the heel and forefoot areas of a shoe is known. U.K.
Patent No. 338,266 to Rayne, ~.S. Patent No. 547,645 to ~acroix, U.S. Patent No. 1,069,001 to Guy, U.S.
Patent No. 2,080,499 to N:lth~ncon, and U.S. Reissue Patent No. 34,102 to Cole, each disclose the basic concept of having rllchirnc rrnt~;n;nrJ prQcsl~r; ~od fluid rl;cprsQ~l adjacent the heel and forefoot areas of a shoe. Each of these tQrhnr~l o~; Q~q pregents its own complications. However, the ovQrr;rl;n~ problem common to each of these technologie8 is that the Cllch;rn;n~
means taught therein are ;nfl~tQ~l with a fluid under ~Le:Q ~ULt:. Each of the above-noted patents discloses a rllch;nn;n~ means wherein a pressurized gas is forced into the c~lch;r~n;n~ means, usually through a valve ~crQc~;h~e from the exterior of the shoe.
There are several ~;ff;clllties associated with using a prQC~Ir;~7Q~l fluid within a rllch;rn;n~ device.
~ost notably, it may be inconvenie~t and tedious to constantly adjust the pressure or introduce a fluid to the rllch;r~n;nS device. Moreover, it is difficult to provide a consistent ~ 8QuLe within the device thereby giving a consistent perf or~ance of the shoes .
In addition, a rllch;nn;n~ device which is capable of holding pressurized gas is ~-, r~t;vely expensive to ~-n~f~ct~re. Eurther, ~LeS~ULiZed gas tends to escape from such a cllch;rn;ng device, rQqn;r;n~ the intro~ rt;~n of ;~ ;tirn~l gas. Finally, a valve whic~ is visible to the exterior of the shoe negatively affec-s the aesthetics of the shoe, and _ _ _ _ ~

W095/20332 2 1 8 1 ~8 PCr/US94/~0895 increases I:he probability Qf the valve being damaged when the shoe is worn.
A cllch;nn;n~ device which, when unloaded contains air at ambient pressure provides several benefits over similar devices rnnt~;n;ng ~L~s~uLized fluid. U.S. Patent No. 2,100,492 to Sindler and U.R.
Patent ~rpl;r~t;nn No. 2,039,717 to Rarhu-Titan both discloae the use of a cushioning device cnnt~;n;ng ambient air. ~owever, neither of these patents provides for the transfer of air between the heel and forefoot portions of the shoe.
Germarl Patent No. 820,869 to W~;nh~ttt et al. and U.S. Patent No. 4, 577, 417 to Cole both appear to disclose a c~h;nn;ng device ~aving heel and forefoot cavities contA;n;ns ambient air. The ~;nh::lrttt et al.
patent appears to disclose ,a ~ t;c shoe warmer insert ~ ; rp~ with two air 1 ' j oined by a tube. The Cole patent discloses a sole and heel structure having ~JL. 1 tlt~tl bulges conn~cted by a pas~ t y, wherein air at a ~ c ~L~8~ULe is disposed within the sole and heel structure.
The te~ hnn1 o~ taught in these patents do not provide for more than one rate or type of air flow between the cavities. Both these patents show a c1l~h;l~n;n~ device having merely a st~;ght atube"
passageway which ~nnn~ct~ the cavities of the device.
This straight "tubea structure results in the passageways providirg only one rate or type of air flow between the cavitie8. Neither the Cole patent nor the 1 ;nh~rdt et al. patent digclogeg a c1l~h;nnt device which may be customized for different types of activities and body weights.

Wo95l20332 2 1 8 1 9q8 A similar disadvantage is present in U.S. Patent No. 4, 458, 430 to Peterson. The Peterson patent describes a cushioning device having r-lqh;nn~ disposed beneath the heel and ~ront tLa~V~L`~e arch o~ the 5 foot. The rll~h;nn~ are partially or completely filled a fluid, which may be of varying viscosities. Similar to the above-noted devices, a major deficiency o~ the Peterson device is that the rh~3nn~ cnnn~ t; n~ the c~l~h;on~ are merely straight "tuben rh;lnnf~lc, of a uniform .1; ~r thluuylluu~ their length. As previously indicated, this structure has` the disadvantage of providing on1y one amount or degree of rll~h;on;n~, which cannot be tailored or ' f;e~l to ~r- ~ te different athletic activities and body types.
Although attempt8 have been made to create valve means which can control or, vary the rate of fluid flow, such attempts have resulted in overly ' ^r~ , complex and expengive structures . U . S .
Patent No . 4, 446, 634 to Jo_nson et al . shows an article of ~ootwear having heel and ball h1~ rs, two c~n~ill;t~ cnnnf~rt;n~ the hla~A~r~ and valves disposed on the rrntlll; t~. By rotating knobs attached to the valves, the rate of fluid flow between the hl;~ rFI
can be regulated. In addition to the ~l;f~;clllties ~q~Qr;;lt~nl with uLr~ Q~ ~luid, the Johnson et al.
patent suffers from several other shortc~~;n~c. Most " n~nt among these are that the ~us parts and intricate interr~ t;on~h;r thereo~ results in a 30 cushioning member which is expensive to ~-m-f~rtllre, and prone to malfunction.
PCT Application No. PCT/GB91/00740 (TntGrn~t;onal pllh1;r~t;on No. W0 91/16831) to Seymour teaches valve means ~, ç:;ng two ribbed members formed ~rom a wo 9s~20332 2 1 8 1 9 q 8 PCT~Us94l0o89s stiff plastic which are disposed above and beneath a capillary tube. Because the ribbed members of the Seymour device are formed of a differe~t material than the cushioning member thereof, the cost of ~-nllfArtllring tbe device is increased. In addition, the ribbed members are designed to "pinch" the rAr; ~ y tube closed entirely during use, which can prevent an ArlP~lAte amount of fluid from reaching the forefoot rontA;nPr prior to forefoot strike. ~urther, the ~Ar;llAry tube of the Seymour device merely q~q a 8trA; ght tube, and thus shares the ;nA~lPqnAr;Pq of other devices digcugsed herein which possess the same f eature .
P~rcn-~9; n~l y, prior to the development of the present i~vention, there was not a shoe which ;n~ v-~tPd a cllqh;on;nr~ member rnntA;n;nrJ ambient air, wherein the cllqh;nn;ng member ;nrlllr~ a - ; rAti nn chalmel having; ^ lAnre meang disposed therein which served to restrict the flow of air between distinct ~ . In addition, prior to the development of the present invention, there was not a shoe which taught altering the structure of the -= means, guch that differently-sized and shaped; ,- cP means provided varyi~g types of air flow between the 1 , and consequently provided varying degrees of c~lqh; nn; n~ . Purther, those shoes which have attempted to use fluid-filled devices incuL~ c,t;nr~ valve means to cushion the foot of a wearer have had such ~ rkq as adding increased weight to the shoe, providing ;nArlPq~lAte and uneven cushioning, and being ;nnr~l;nAtPly complex and expensive to r-nllf~tllre.
Therefore, it is _n object of the present invention to provide an article of f ootwear having Wo95/20332 2 1 8 1 998 PCT~S94,00895 enhanced cushioning and energy- returning characteristics .
It is a further object of the present invention to provide an article of f ootwear having a cushioning member rr,ntA;n;ng ambient or slightly pressurized air.
It is a further o~j ect of the present invention to provide an article of footwear having a rllqh; rn; n~
member with; ~ e~lAnre means which restricts the flow of air between ,' ' - .
It is a further object of the present invention to provide an article of footwear having a r~ h;rn;n5 member which is capable of providing varying amounts or degreeg of r~l~h;r,n;n~.
It is a further object of the present invention to provide an article of footwear having a rll~h;rn;
member which will r^-;ntA;n its rllqh;r,n;
rhArArt~r; ~tic8 tl~uuylluu- the life of the shoe.
It is a further object of the present invention to provide an article of footwear having a rll~h;rn;ng member ~uLLuu~ded by a st~hl; 7;n~ rim and cr~vered by a trlr which ~nhAnr~ the rll~qh; r,n; ng rh~rAr~t~ristic9 of the rll~h;rn;n~ member.
It i8 a further o~ject of the present invention to provide an article of footwear having a rll~h;rn;ng 25 member which may easily be incorporated in either a lef t br a right shoe without modif ication to the member.

wo gs/20332 2 1 8 1 9 9 8 PCT~S94/0089~ ~

It is a ~urther obj ect o~ the present invention to provide an article of footwear having a rilch;nni member which is simple and inexpensive to manufacture.
Si-=ry of the Invention To achieve the foregoing and other objects, and in ;irrnr~izinr~ with the purposes of the present invention as embodied and broadly described herein, the article of footwear of the present invention c c~c a sole and a rPq;1;~nt rllch;nn;n~ member rnni- iin;n~ air at am~ient p~e:87-lu~ 'i;Cp ig~'i within the sole. The cl~ch;nn;n~ member ;n.~ a first chz~er, a second chamber and a ~~ zit; nn chamber rnnn~ct;ng the first and second ' . The ;czit;on chamber has an average cr0ss-cect;
area which i8 less than the average cros8-Be~t;-~nz area of both the first and se~ond ~ T _ ' r~
means for restricting the flow of air between the f irst and second ' is disposed within the ; cat; on chamber and has an average cross-sert;nnZil area less than the _ ;n~r of the communication chamber.
The sole may comprise a midsole having a cavity portion, wherein the r~ch;nn;n5 member is disposed within the cavity portion. Alternatively, the sole may comprisé an outsole having a cavity portion, wherein the r-lch; nn; "~ member is dispoged therein.
The sole may also comprise an insole having a cavity portion, wherein the rllch;fm;n~ member is disposed therein. The article of footwear may ~urther comprise a sockliner having a cavity portion disposed within a upper, wherein the cushioning member is disposed within the cavity portion of the sockliner.

Woss/20332 2 l 8 1 q~8 PCT/US94/00895 g The cushioning member may be f ormed of a blow-molded elastomeric r-t,or;~l The article of footwear - may further include a moderating member disposed above the cushioning member for defusing impact forces upon the ml~h;nn;n~ member and providing support to the foot of a wearer. The moderating member may be formed of a material having a Shore A hardness of 75-95 or Shore C h~rrln~ of 55-75. The moderating member may be ;nte~r~l with the sole of the article of footwear.
The sole of the present invention may further comprise a heel portion and a forefoot portio~, and the fir8t and second ~ of the ~ h;nnin~ member may be disposed adjacent the heel and forefoot portions of the sole, respectively. Flexure grooves may be 1; ~pos~ on the second chamber of the ;nnin~ member. A partition may be disposed on one of the first and second ' - :i for altering the direction of the air flow within the cllF~h;nn;n~
member .
The;, ~~ means of the present invention may be HUb~ ;;llly hourglass-8haped~ or, alternatively, may be ~ "t;~lly nzn-shaped, subst~nt;~lly nwn-shaped, or ~ lhst ~ n t; ~ 1 1 y n 8 n - shaped .
The c~h;nn;n~ member may further comprise an upper portion and a lower portion which are mirror images of one another, such that the ml~h;nn;n~ member may be readily disposed in either a lef t shoe or a right shoe.
Alternatively, the article of footwear of the 3 0 present invention comprises a sole having a heel portion, an arc~ portion and a forefoot portion, and a cavity portion formed within the gole ~t~n~l;ng W095/20332 2 ~ 8 1 998 PCr/USs4/00895 ~

suhst~nt;~lly from the heel portion to the forefoot portion thereof . A non-r~ -hl e, resilient ~irst chamber rnnt~;n;ng ambient air is disposed within the cavity portion ad~ acent the heel portion. A non-S pl hle, resilient second cha~ber r~nt~;n;ng ambient air is disposed within the cavity portion adjacent the f oref oot portion . A non - r' hl e ,- i r~ t; rln cha~ber r~nt~;n;ng ambient air is fl;~posPfl within the cavity portion adjacent the arch portion, and r~nn~rt~
the f irst and second I ' ' , T - ' re means is disposed within the communication cha~ber and has an average cross-sect;rn~l area which is smaller than the average cross-sect;rnAl area of the l infll-r of the ;r:lt;~n chamber. The; _ _ means restricts the flow of air between the first and second ~
and provides f~nh~nr~fl c~h;~-n;n~ to the article of footwear by controlling the velocity at which the air moves between the f irst and ~econd ~ ' ' ~ .
The article of footwear may be formed of an 2 0 unitary piece of blow-molded elastomeric material .
The; _ re means may increase the velocity and t~rh~ nre of the air as it moves between the first and second 1 ' ^rq The ~ 'r~tirn chamber may be sized and shaped to provide t~rh~ nt air flow between the f irst and second ~ ' ' when the weight of a wearer applies downward ~L~8~uLe to the first cha~ber.
Alternatively, the ~ r~t;~n chan~ber may be sized and shaped to provide laminar air flow or transitional air flow between the first and second ~' ' when the weight of a wearer applies downward pIefi~uLè to the f irst chamber .
Ridges may be fl;~Fr,8~fl on the upper= and lower surfaces of the c~ ; rF~t; /~n chamber. The vertical distance between the upper and lower ~rfz~c-~ of the W0 95/20332 2 1 8 ~ 9 9 8 PCT/US94100895 second chamber may be less than the vertical distance between upper and lower surfaces of the first chamber.
A moderating member may be disposed above the cavity portion for ~ inr~ impact forces upon the cushioning member and for providing support to the foot of a wearer. The sole of the present invention may further comprise an upper surface and a lower surface, wherein the cavity portion is formed within the lower surface of the sole, and the ' t;nrJ
member comprises the upper surface of the sole.
Alternatively, the article of footwear of the present invention may comprise a sole and a resilient rllQh;nn;n~ member crnr:~;nin~ ~,L~:g~uLized air fl;cpnQPfl within the sole. The rllQh;nn;nr~ member ;nrlllflPQ a first chamber, a second chamber and a co=ication chamber rnnnPct;n~ the first 2nd second, ' . The rl ;C~tinn chamber has an average cross-sect;nnzll area which is less than the average crogS-8Prt;nnzll area of both the first and second c' -- D. T ' ~rP
means for restricting the flow of air between the first and second ~ is disposed within the communication chamber and has an average cross-gPrt;nnz~l area which ig legs than the L~ ;nflPr of the communication chamber.
Brief Descriptio~ of the D~ n~Q
The AC ~ ying drawings, which are incuL~oLGted in and form a part of the specification, illustrate various embofl; ~ of the present invention and, together with the desrr; rt; rn, serve to explain the pr;nr;rles of the invention. In the drawings:
FIG. 1 is a top plan view of a c-l~h;nn;nr, member in accordance with the present invention;

WO 95/20332 2 l 8 1 9 9 8 PcrluS94/00895 PIG. 2 is a medial side view of the f~ h; ~m; n~
member of FIG. 1;
FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1;
FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1;
FIG . 4A is a cross - sectional view taken along line 4A-4A of FIG. 1;
FIG. 5 is an exploded view of one possible interrPlAt;~n~h;r of a ~ t~r, r~ h;< n;n~ member and cradle in A~ rflAnrP with the present invention;
FIG. 5A is a cross-sPcti~nAl view taken along line 5A- 5A of FIG . 5;
FIG. 6 is a top plan view of an; ~ P means in accoL~ce with the present invention;
FIG. 7 is a cross-sectlnnAl view taken along line 7-7 of FIG. 6;
FIG. 8 is a cross-sectional view taken along line 8-8 FIG. 6;
FIG. 9 is a top plan view of an alternate : ' -'; of;, ' -~ means in accuL~ with the present invention;
FIG. 10 is a cross-sect;nnAl view taken along line 10-10 of FIG. 9;
FIG. 11 is a top plan view of an alternate : ' '' of; -~ means in ~A~c~rflAnre with the present invention;
FIG. 12 is a cross-spct;nn~l view taken along line 12-12 of FIG. 11;
FIG. 13 is a top plan view of an alternate of; ~ means in A~ with the present invention;
FIG. 14 is a cross-sPct;~)nAl view taken along line 14-14 of FIG. 13;

Wo gs/20332 Pcr/usg41oo89 FIG. 15 is a top plan view of an alternate embodiment of a midsole in accordance with the present invention;
FIG. 16 is a bottom plan view of the midsole of FIG. 15;
FIG. 17 is a top plan view of an integrated '~ rzl tQr and midsole in accordance with the present invention;
FIG. 18 is a bottom plan view of the integrated ' tor and midsole of FIG. 17;
FIG. 19 is a sectional view taken along line 19-19 of FIG. 18;
FIG. 20 is a top plan view of an alternate : ' '; of a rllsh;r~n;n~ member in accordance with the present invention;
FIG. 21 is a ~ ~e~l ;ve view of an alternate : ' _' of a cllqh;~n;n~ me~ber in ~rcorfl~nre with the present invention; and FIG. 22 is a pGrf~pert;ve view of an alternate : ' ofl; of a r--Rh;r,n;n~ member in accordance with the present invention.
D~ ed Descrlpti of the Inve~tion Ref erence will be made in detail below to the preferred : ' -~' -t of the present invention illustrated in the ac~ ying flr~w; n~R . It should be noted that similar or iflGn~ structure is ;flGnt;f;Gfl using iflGnt;r~l reference nu~bers.
Referring now to the preferred: ' -'' t.q, a cushioning member in accordance with the present - 30 invention is shown generally at 10 in FIG. 1. The cushioning member provides cr,nt; nllr,usly modifying cushioning to an article of footwear, such that a wearer~s stride forces air within the r~lRh;r~n;ng _ _ _ _ . , . . . , .. _ . ... _ ... . .. _ . _ Wo95l20332 PCrlUS94/00895 member to move in a complementary manner with rf spect to the stride.
FIG. 1 is a plan view of the top of a cushioning member in accordance -with the present invention ~owever, FIG. 1 may in fact be either a top or bottom plan view, as the top and bottom of the cushioning member 10 are substAnt;Al ly mirror images of one another. In light of this ~ Lr; cal construction, the ~rllqh;f)n~ng member of the present invention may readily be incorporated within either a lef t or a right shoe. It will be appreciated that the symmetrical structure of cl~#h; ~n; ng member 10 increases the ease and reduces the expense of ~-mlfprt7lring cushioning member 10.
f~lch;r,n;n~ member 10 ig a three-dimensional structure inrllltl;nrJ a first ,portion 12 and a second portion 14. First portion 12 and second portion 14 form the upper and lower surfaces of cllqh;r~ning member 10. In A~l~;t;nn, first portion 12 and second portion 14 join to form a first q;~ 1l 20 and a second qif' 1l 22. ~lch;r,n;n~ member extends ~Lall~v~ ely from first q;~ - 1l 20 to secorld si~' - ll 22, and extends forwardly from heel or rear tPrm;nl-c 18 to front tPrm;m~q 16. First portioIl 12 and secorld portion 14 are rr~nnPCtPCl along a pPr;rhPrAl edge 24, which results from a preferred molding process ~discussed below) used to form r~llch; nn; ng member 10 .
pPr; rhf~r~ l edge 24 help8 hermetically geal cushioning member 10. ~PrPn~l;nrJ upon which shoe (the left or the right) rllch; r~n; n~ member 10 is incorporated within, first portion 12 may comprise either an upper surface or a lower surface.

Cushioning mernber 10 is formed of a suitably r~q~ n~ material so as to allow cllqh;nn;n~ member 10 to compress and expand while also resisting breakdown.
Preferably, cushioning member 10 may be formed from a - 5 host of Thermoplastic E~astomers. Suitable materials used to f orm cushioning member 10 may include various ranges o~ the following physical properties:
Lower Upper k~ ~
Density (Specific Gravity in g/cm') 0.80 1.35 Modulus 6i 3009~ Elongat;on (p8i) 1,000 6,500 P-~ Set @ 20096 Strain (~) 0 55 Compression Set 22 hr/23 C 0 45 Eardness Shore A 70 Shore D 0 55 Tear Strength (~/m) 60 600 pf.. .- -n_,.l Set at Break (~) 0 250 Many materials within the class of ,l~tic Elastomers (TPE's) can be llt;1;7~fl to provide the above physical characteristics . Th, ,1 ~qtiC
Vulcanates (such as SARLIN~ from PSM, SANTAPRENE from r~lnnc~nto and ~RATO~ from Shell) are possible ~-tF~r;:~l q due to physical ~ h~rArt~risticsl processing and price.
Elowever, at present Th~rmnpl ~qtiC Urethanes (TPU' s) such as pT~r.TFT~l~ from Dow, ESTANE from B.F. Goodrich and ELASTOLL~N from B~SF (to name but a few) provide the best overall physical characteristics and consequently are the pre~erred choice w095~20332 21 ~1 998 PCrrUss4/oo89s The preferred method of manufacturing cushioning member 10 is via extrusion blow molding. It will be appreciated by those skilled in the art that the blow molding process is relatively simple and inexpensive.
Further, each element of the cushioning member of the present invention is created during the same pre~erred molding process. This results in a unitary, "one-piecen rllRh;nn;n~ member, wherein all the unique elements of the cllqh;nninrJ member discussed herein are a~ l; qh~l using the same mold.
~lqh;nn;n~ member 10 is a hollow structure preferably filled with ambient air. It ia; La~L
that rllqh;rn;n~ member 10 be; _ hle to air; i.e., hl ~~;r~lly 8ealed, such that it is not pn,qs;h1e for the ambient air tl~pn,q~otl therein to escape upon application of force to rllqh;nn;n~ member 10.
r~lly, there may be diffusion in and out of rllqh;nn;n~ member 10. The unloaded yLes,,uLe within rllqh; nn;ns member 10 is preferably equal to ambient ~Les~uLe:. Accordingly, rllqh;rn;n~ member 10 retains its ~l-qhi nn; n~ properties t~Luuyl~uuL the life of the article of footwear in which it is incoL~uLated.
As can be seen with ref erence to FIG . 1, rllqh;r,n;n~ member 10 is pre~erably a unitary member comprising three distinct c q: a first or heel chamber 2 6, a second or f oref oot chamber 42, and a third or communication chamber 58. Heel chamber 26 is generally shaped to conform to the outline of the bottom of an individual ' s heel, and is disposed beneath the heel of a wearer when rllqh;nn;ng member 10 is incoL~uLated within a shoe. 3Ieel chamber 26 extends tL~iveL~ely from ~irst s;-l~ 11 20 to second q;~ 11 22, and extend8 forwardly from heel tPrm;n--q 18 to rear arch t~n;nllq 32. Angled tr~nq;t;on walls -Wo 95/20332 2 1 ~3 1 9 9 8 PCTrUS94/0089 31 are disposed adjacent rear arch terminus 32 of heel chamber 26. A directional partitior, 34 may be disposed within heel chamber 26, and if so, serves to subs~Ant;~lly divide heel chamber 26 into two regions:
medial heel region 36 and lateral heel region 38. A
sealed molding port 40 is disposed adjacent rear terminus 1~, indicating the area where a molding nozzle was positioned during a preferred r-mlfa~tllrin~
proces8 discussed above. Port 40 may easily be removed (such as by cutting or shaving) during the r~mlfActllring process.
n~p,~ oppo~ite heel chamber 26 is a second or ~orefoot chamber 42. Forefoot chamber 42 ig g--n~r:llly shaped to conform to the forefoot or -:~t:or~l area of a f oot, and is ~ po~cl beneath a portion of the forefoot of a wearer when incorporated within a shoe.
Forefoot chamber 42 extends ,tL~v~Lt~ely from first 11 20 to second gidewall 22, and extends rearwardly from front t~rm;mlC 16 to forward arch tPrm;m~ 48. Preferably, the volume of air within forefoot chamber ~2 is sul~Y~ l1y the same as the volume of air within heel chamber 26.
A small ;n~l~nt~t;~n or notch 52 extends inwardly from front t~rm;ml~ 16. Similar to heel chamber 26, forefoot charnber 42 may include a dire~t;~.n~l partition 34 which serves to subst~nt;~lly divide forefoot chamber 42 into two regions: medial metatarsal region 54 and lateral ~ t~rS~l region 56.
A series of flexure grooves 50 extend L~antiv~:Lrlely across forefoot chamoer 42. Flexure grooves 50 comprise ;n~ nti~t;r)n~ or valleys formed within first surface 12 and second surface 14 of forefoot chamber 42, and facilitate the flexing or bending of forefoot _ _ _ ~

WO 95/20332 2 1 8 1 ~ 9 8 PCrNsg4l008ss chamber 42 during an individual ' 8 gait, especially during the "toe-off ~ phase of the gait cycle Disposed between heel chamber 26 and forefoot chamber 42 is a communication chamber 58.
Communication chamber 58 comprises an elongated, subst~nt; ~1 1 y straight chamber which r~nn~rt~ heel chamber 26 to forefoot chamber 42. Communication chamber 58 extends tL~Yve~ely from first si~ l 20 to second c; ~ - 1 1 22, and exten~s f orwardly f rom a posterior region 64 adjacent rear arch t~rm; nllq 32 of heel chamber 26 to an anterior region 66 adjacent forward arch t~rminl~q 48 of forefoot chamber 42.
Ridges 68 may be l;cpos~d adjacent- ~nrF-r;or region 64 and posterior region 66 of ;r~t;r~n chamber 58. Ridges 68 facilitate the use of r-lch;r,n;nrJ member 10 within either a left or a right shoe, by allowing rllqh;~n;n~ member 10 to flex and bend to ~ _ t-~ the last bottom shape of both left and right shoes. Further, ridges 68 help prevent ~ nq;~n of, ;r:~t;on chamber 58 and increase the tllrhlll~nre of air flow within rl-qh;rn;nJ member 10, as will be rl; cc~qsed below. Locator flanges 72 may also be disposed adjacent ~nter;nr region 64 and posterior region 66 of communication chamber 58. Locator flanges 72 can be used to assist in the rl~c of c~qh;rn;n~ member 10 within an article of footwear, as will be adJ~ssed herein.
Central to the present invention is the inrlllqir,n of; ,- -r~ means 74 within communication chamber 58.
T _-dCLL~C~ means 74 comprises a restriction or convolution in communication chamber 58 which restricts the f low of air through communication chamber 58. ~cq~nr;~lly ; means 74 comprises WO 95/20332 2 ~ 8 1 9 9 ~ PCrlUS94/00895 a communication channel 80 formed and bordered by restriction walls 78. In FIGS. 1, 5 and 6, impedance means 74 is shown as being subst~nt;Al ly "hourglass"-shaped }Iowever,; ,~lAnce means 74 may comprise numerous shapes or 8tructures. For example, FIGS. 9-14 show some of the other forms; ,_ re means 74 may take. FIGS. 9-10 8how impedance means 74 as being substAnt;Al ly "w"-shaped, FIGS. 11-12 8how i, e means 74 as being subst~ntiAl ly nzn-shaped, and FIGS.
13-14 show;, _ ' --e meang 74 ag being 8ub8t;~ntiAl ly i~ 8 n _ ghaped .
- means 74 increases the resistance to air flow by increasing the turbulence within the air ~low. me shape or structure of;, - -~ e means 74 tlPt~;n-~q the amount of air or type of air flow that is permitted to pass through ~ ' r~At; nn chamber 58 at any given time . For example, of the '; ~ q illus trated, the " hourglass n - shaped i , e 1A n re means of FIGS. 1, 5 and 6 provides the least resistance to air flow, while the "sn-shaped; ,- -re means of FIGS.
13-14 offers the greatest re8istance. Because the differently-shaped; ,- -ne means provide different types of air flow, it follows that they also provide different degrees of cllqh;nn;n~ That is, the structure of; ,- ~e means 74 sig~ificantly affects the degree of cllqh;nn;n~ provided by heel chamber 26 and forefoot chamber 42 of cushioning member 10.
Accordingly, different t ,- ce means can be used to Ac~ te various typeq of athletic activities, as - 30 well as different body weights. For example, one structure of impedance means can be provided to ~A~C. ~f' walking gait rAtternq, while a different structure can be used to suit running gait patterns.
This is a signif icant i~ JL~ . ' over previously-known cllqh;nn;n~ devices, which merely have straight _ _ _ _ _ . _ _ _ _ _ _ _ _ . , .. ... _ . .. _ , . . . _ .

woss/20332 2 1 8 1 9 9 8 p~"~s9~00895 "tubes~ offering only one type or degree of cushioning .
The different structures of the impedance means of the present invention are Arr , l; Ch~fl during the preferred blow-molding r--nl~f~rtllring process described above. Arrorr~;ngly~ no complicated or expensive valve means need be ~tt~rh~fl to cushioning member 10.
Rather, the shape of; -' -re means 74 is det~n; necl by the same mold uged to f orm the 1~ ; n~ r of rllqh;nn;n~ member 10.
As noted above, the shape of; _- ~ means 74 will affect the rate and rhArArtpr of air flow within rllch;nn;ns member 10, in particular between heel c_amber 26 a~d forefoot chamber 42 thereof.
lZ~nt;~lly, there are three rero~n;~ types of air flow: "laminar, n ntransitrionaln and ntllrhlll~ntn (however, at times transitional flow is ignored, and only laminar and tllrhlll ~nt flow are referred to) .
haminar air flow moves in a smooth manner such that its vl~lor;tir~c are free of macroscopic flllctll~t;nnq As the flow of air becomes more erratic, it enters a phase referred to as transitional flow, where the air flow acts primarily like laminar flow, with sporadic outbursts. In turbulent flow, the largely regular motion of laminar air flow is deDL--,ycd; the air flow u.lde~,es a transition, ~_ 'n~ nthickern and having random .c within the air flow; i.e., turbulence.
In the chaotic phase of air flow referred to as turbulence, distllrhAnr~c such as shear, impulse and viscous forces co~e into play.
Each of the embo~l; c of the present invention provide for different flow characteristics. These rhArArt~r;~ticg affect the performance of cllch;nn;nrJ

WO9S/20332 PCr/US94/00895 member 10. For example, if the cross-section dimensions of the "hourglass" : ' orl; t of the impedance means (as shown in Figure 1) are 3.17mm X
4.76mm, the Reynold's Number of the air flow from heel s chamber to forefoot chamber is apprrnr;"~t~ly 1451, meaning the flow is laminar. Conversely, if the cross-sPrtlrn~l area of the same ' ~'; of impedance means is 1. 5mm X 3 . Oomm, the Reynold' s Number has been found to be apprry;r-t~ly 2651, meaning the flow is transitional. For ~uL~es of the above calr~ t;r~n~ the Reynold's Number was defined as Re = VpD where V is the fluid velocity, p i5 the fluid density, D is the equivalent rl;; er of the flow region, and 11 is the dynamic visco8ity of air.
The eguivalent diameter is the ~1; er of a circular duct having the same area as the rectangular duct u8ed in the preferred G -' ~ of the invention.
Several ~ n~ were made in doing the above-referenced calc~ t;~n~ (such as an ab~ence of f~h~;lr;n~ forces, and an assumption that heel strike occurs on a perfectly horizontal plane), and therefore the numbers reflected should be viewed as 8~ , t;onq of what occurg in the system, not precise numerical 5~1 ut; on~
Rrt-lrn;n~ now to the drawing figures, as previously indicated, rll~h;rn;ng member 10 is formed of a suitably r~ nt r-t~r;~l 80 as to enable the heel and forefoot ~' - 26, 42 thereof to ~ , G8~
and expand. While communication chamber 58 is preferably formed of the same rP~ nt material as the two oppositely-disposed ~ adjacent its ends, communication chamber 58 is preferably constructed so as to prevent or subst~nt;~l ly limit any compression or r~n~; rn thereof . Preferably, this is achieved in part by making communication . . . _ . _ . . _ . . . _ _ . .

WO ss/2o332 2 1 8 ~ 9 9 8 P~ T/Usg4/oo89~ ~

chamber 58, and particularly i ,^~l~n~e means 74 thereof, 6uch that they each possess a smaller cross-sectior,al area than both heel chamber 26 and forefoot cha~er 42.
A comparison of various Figures reveals the differences in the cross-sPct;nn~l areas of these As can be seen in FIG. 1, the transverse width d6 of ;n~t;nn chamber 58 is less than the LL~vt:L:5e width dl, d2 of heel cha~ber 26 and forefoot chamber 42 . Further, the tl~Yv~ r~e width of ; _-' means 74 is less than the tlc-n~V~ e width d6 of the L~ ;n~l~r of ~ t;nn chamber 58. As can be seen with reference to FIG. 2, the longitudinal height d5 of ~ ;n~;nn chamber 58 is less than the longitudinal height d3, d4 of heel chamber 26 and forefoot chamber 42. Further, the longitudinal height of ;, ' ne means 74 may be less than the longitudinal height of the L ; nrl~r of communication chamber 58, although in FIG. 2 the longitudinal height of communication chamber 58 is shown as being ~ub~ l y cu-l~,Lal.L ti~ ~ vu~J~ its length.
The difference in the cross-EPct;nn~l areas of the afuL~ ;nnP.~ is further evidenced upon reviewing FIGS. 7-14. FIG. 7 is taken along line 7-7 of FIG. 6, and shows the average cross-sec~;nn~l area of, ;n~t;nn chamber 58 apart from; ~- ~ rP means 74. FIGS. 8, 10, 12, and 14 clearly show that the average cross-sec~; nn~l area of; , ' means 74 is less than the average cross-s~rt;nnAl area of the L~ ;n~ of ~ ;na~ n chamber 58, regardless of the: ' -'; of; ,^~l~nne means 74 employed.
The reduced cross - sectional structure provides a rigidity to communication cllamber 5a and; ,-~ -n~

-Wo 95/20332 2 1 8 1 q 9 8 PcTlusg4/oo895 means 74 thereof that reduces any appreciable expansion or cnntr~ct;on of these elements.
Additionally, the riyidity of communication chamber 58 may be provided by making the walls of - ; rat; on chamber 58 thicker than the walls of the L~ ; n~ r of rll~h;nn;ng member 10. For example, one possible construction would be to have the walls of heel chamber 26 and forefoot chamber 42 apprnyir-t~ly 1.5 m; 1 l; t~rfl thick, and the walls of communication chamber 58 apprnY~-t-~1 y 2 . 5 m; l l ;~ Pr~ thick.
In order to appreciate the manner in which rll~h;nn;n~ member 10 may be incoL~oLaLed within a shoe, FIG. 5 discloses one pn~s;h1e =er of incuLyULation~ Figure 5 is an .~1 on~ view showi~g cll~h~nn;n~ member 10 rl;~posPd between a ~ t;n~
member 88 and a rim or cradle 104. In the ' shown in FIG. 5, '^r;lt;n~ member 88 comprises part of a sockliner 89, and cradle 104 comprises a midsole.
Sockliner 89 ;nr1~ c a foot supporting surface 90 having a forefoot region 92, an arch support region 94 and a heel region 96. A peripheral wall 98 extends upwardly from and riuLLuund8 a portion of foot supporting surface 90. Disposed on the lln~r8~ of sockliner 89 is a ^r~t,n~ surface ~ ~;nr~
2S r-lrl~rAtor 88. Mntl~r~nr 88 acts as a stiff "plate"
between cushioning member 10 and the foot of a wearer.
Preferably, ~^r~qtnr 88 ig formed of r~~r;~1 havi~g a h~rrln~s of Shore A 75-95 or Shore C 55-75.
Pot~nt;~1 materials used to form '^r~tor 88 include EVA, PU, polypropylene, polyethylene, PVC, PFT, f;h~rh9~rd and other thl , 1~tics which fall within the afuL~ ; nn~l hardness range. The relatively stiff material acts as a moderator for foot strike, preventing the foot of a wearer from collapsing into _ _ _ _ ~ _ _ _ . . . . .. .

Wo 95/20332 2 1 8 1 9 q 8 Pcr~luss4loo895 the center portion of rll~h;r,n;ng member 10, and diffusing impact forces evenly upon rllqh;nn;nr, member 10, thereby reducing localized pressures. Although '^r::ltr~r 88 i8 8hown in FIG. 5 ag being part of a sockliner, it will be appreciated by those skilled in the art that moderator may alternatively comprise any structure that AC- l; qh.~fl the above- ; r,n~d '^rAt;ng function, ;nrlllfl;n~ part of a midsole, outsole, insole, or a ~ nAt;r,n of these elements.
Indeed, it is preferred that ' tr,r 88 comprise a "plate" which is ;ntF~rAl with cradle 104 of the present invention, as discussed below.
Disposed beneath '' ~or 88 in FIG. 5 is a rllqh;nn;n~ member in Arc~ re with the present invention. It will be noted that the rll~h;r~n;ng member of FIG. 5 differs _ from that shown in FIG. 1. For example, rlls~h;r,rl;n~ member 10 of FIG. 5 does not include locator flangeg, which are an entirely opt;rn~l feature that do not directly r~mtr;h~tF~ to the cll~h;r,n;n~ effect of rll~h;t~n;ng member 10. Further, the gtructure of dir~t; nn7sl partition 34 in FIG. 5 differs from those of FIG. 1.
In the -'i shown in FIG. 1, directional partitions 34 essentially comprise elongated, unitary walls formed by grooves within first surface 12 and second surface 14 of both heel chamber 26 and forefoot chamber 42 (see, e.g., FIGS. 4 and 4A). Conversely, in FIG 5, two discrete direct;rn~l partitions 34 are ~1; qp~qed within forefoot chamber 42 only. Each directional partition 34 ~qR~nt;Ally comprises a short wall formed by small ;nfl~ntpt;r~n~ within first surface 12 and second surface 14 of forefoot chamber 42 (see, e . g., FIG . 5A) .

Wo 9sl20332 2 1 8 1 ~ 9 8 PCrlUS94/00895 -2s -With rnnt;ml;ng reference to FIG. 5, disposed beneath cushioning member 10 is a cradle 104 comprising a midsole. It has been found that in order to most effectively complement a gait function, cushioning member 10 preferably comprises a core of more, ~l;Ant cllch;nn;n~ bULl-JU~ded by a midsole or similar structure that is stiffer than cll#h;nn;ng member 10, and creates a nrrA~1l ;ng" effect to cushioning member 10. In FIG. 5, this cradle is shown as being a midsole. ~idsole 104 has a top surface 106 ;nrlll~;n~ a toe portion 118, a forefoot portion 120, an arch or middle portion 122 and a rear portion 124.
Locator flange receiving means 100 may be tq~#pn#efl on top surface of midsole 104 (~ee, e.g., FIG. 15). An F.YtPr; rr ~ l l 126 extends around the medial side 128 (not shown) and lateral side 130 of midsole 104.
A pattern 132 is ~;#rn#ed on exterior #;~ 126, as are outsole-engaging notcheg,l34. ~-tl~r;nr .#ir~
126 may be constructed so that rll~h;f~n;n~ member 10 is visible from the ~rt~r; nr of the shoe.
A cavity 138 i8 formed within and extends ly through midsole 104 from top surface 106 to bottom surface 140 thereof. Cavity 138 extends generally from rear portion 124 to forefoot portion 120 of midsole 104, and forms an interior #;~' 1 l 142 withinmidsole 104 which is ~ub~ t~lly ;rl~nt;rAl in shape to the outline of p~rirh~rAl edge 24 of rllch;nn;n~ member 10.
A rim 144 extends upwardly from and ~uLL~u"d8 a portion of top surface 106 of midsole 104. In the illustrated aLLauy~ of FIG. 5, midsole 104 receives c~h;nn;ng member 10 such that peripheral edge 24 of rll~h; nn;ng member 10 cnntArt~ interior sidewall 142 formed by cavity 138 substAnt;Ally about _ _ _ _ _ _ _ . .... . ...

WO95/20332 2 1 8 1 9q8 PCrlUSs4lOOgss the entire periphery thereo~. When cushioning memher 10 i8 placed ~ithin cavity 138, top 8urface 106 of midsole 104 is aubgtAnti~lly flugh with rllchinning memher 10. However, heel chamber 26 and forefoot chamber 42 preferably bulge slightly above top surface 106 of midsole 104, in order to f~cil;t~tp the rl~chinn;n~ effect of rllch;nn;n~ memher 10. Although in the illustrated Pmho~ of FIG. 5 rllch;nn;
memher is disposed within a midsole, those skilled in the art will appreciate that rllch;nn;n~ member 10 may Al tprnAt~vely be di8poged within a cavity formed within an outsole, an insole, or even within a shoe "upper, ~ such as in a snrkl ;nPr ~i cpo~e~g within the upper .
In order to fully appreciate the CllCh; ~n; n~
effect of the present invention, the operation of the present invention will now be,described in detail. As previously indicated, cushioning member 10 is disposed within an article of footwear (not shown). When stAt;nn~ry~ the foot of a wearer is ArlPq~ t~ly r~lchir,nPrl by rllchinn;n~ member 10. When the wearer begins a stride, the heel area of the article of footwear rrntArtc the ground or other support surface first. At this time, the weight of the wearer applies d~ : pLe~iULI: on heel chamher 26 of cllchicn;
member 10, causing first portion 12 of heel chamber 26 to be forced rl~ mlly toward second portion 14 thereof. ~e ~, ~e~sio~ of heel ch~mber 26 causes the air within the chamber to be f orced f orwardly, through communication chamber 58, into forefoot chamber 42. The velocity at which the air flows between chambers depends upon the structure of communication chamber 58, particularly the structure of; ~ Anr~ means 74.

WO 95/20332 PCr/US94100895 As air passes through communication chamber 58, ridges 68 help increase the turbulence within the air flow. The turbulence in the air flow is further increased as the air passes through impedance means - 5 74. As previously described, the manner in which and degree to which turbulence increases is a factor of the shape of impedance means 74. In the . ' ~ ';
shown in FIGS . 1, 5, 6 and 8, the air is Pq~ nt; zl 1 1 y funneled in a straight manner through the reduced cross-sectional area of i ,~ e means 74. In the : ' ' shown in FIGS. 9-10, some air is channeled straight through a narrow c~ ; rAti nn channel 80 formed and buld~Lt:~ by resistance walls 78, while other air is routed into diversion rh~nnPl ~ 82 formed and bordered by resistance walls 78. Those gkilled in the art will appreciate that this construction creates more turbulence in the air f low than does the "hourglass" construction pre~iously described.
In the -'; of t ~-' ce means disclosed in FIGS. 11-14, the air flow subst~nt;~l ly reverses direction while travelling through communication channel 80. In the ' of FIGS. 11-12, the turbulence in the air flow is further increased by the air passing through circular rotaries 84. In the '; of FIGS. 13-14, turbulence in the air flow is further increased as the air flow hits several resistance walls 78 comprising right angles, and passes through subst~nt;~lly rectangular ports 86.
Those skilled in the art will appreciate that, of the - 3 0 emb~fl; ~ shown in the Figures, the _ '; - of FIGS. 13-14 provides the greatest resistance to air flow.
The flow of air into f oref oot chamber 42 causes forefoot chamber 42 to expand, which slightly raises WO9S/20332 2 1 8 1 998 PCT/US94/008s5 the forefoot or metatarsal area of the foot. It should be noted that when forefoot chamber 42 expands, the f irst and second portions 12, 14 thereof assume a somewhat convex shape. When the forefoot of the wearer is placed upon the ground, the ~rr~
forefoot chamber 42 helps cushion the corr~f~r~nnl;ng impact forces. As the weight of the wearer is applied to the forefoot, the ~ d pressure caused by the impact f orces causes f oref oot chamber 42 to compress, f orcing the air therein to be thrust rearwardly through comm~unication chamber 58 into heel chamber 26.
Once again, the velocity at which the air flows from forefoot rhAmher 42 to heel chamber 26 will be rm; n~1 by the structure of i , - ~ means 74 .
After "toe-off, n no ~ - ' yLe5~ULe is being applied to the article of footwear, 80 the air within h;~n;n~ me~mber 10 ghould return to its normal state. Upon the next heel strike, the process is repeated.
In light of the foregoing, it wiil be understood that the cllqh;nn;n~ member of the present invention provides a ~=variable, non-static ~l-qh;~m;ng, in that the flow of air within cllqh;~n;n~ member 10 complements the natural biodynamics of an individual's gait.
Because the nheel striken phase of a stride or gait usually causes greater impact forces than the n toe-off " phase thereof, it is anticipated that the air will flow more quickly from heel chamber 26 to forefoot chamber 42 than from forefoot chamber 42 to heel chamber26. ~;m;l~ly, impact forces areusually greater during rurning than walking. Therefore, it is anticipated that the air f low will be more rapid and Wo 95/20332 PCr/TJS94100895 more turbulent between the chambers during running than during walking The foregoing description of the preferred ~ ' _'; has been - prese~ted for purposes of illustration and description. It is not ; nt~n~ l to be exhaustive or to limit the invention to ~he precise form disclosed, and obviously many modifications and variations are possible in light of the above t~:~rh;n~c, For example, it i9 not nP~ y that the r~ h;~m;n~ member, f~per;~l ly the heel, forefoot and commUniCation rl ' thereo~, be shaped as shown in the drawings. ~ of other shape8 may function equally as well. One modification would be to construct the ~ of the heel and forefoot 15 , ' 80 as to ., '~e bellows, to further f~r;l ;t~te the ~' ~ flexing of the ~ ' . In addition, there need not be specific forefoot, heel and communication ~' - . Por example, all three ~ ' may be ~ p~sl~d only in the f oref oot area, and the; ed~ncl~ means would control the air flow between the two oppositely ~ rr~ed forefoot chambers.
With ref erence to FIGS; 1 and 5, it will be appreciated that cushioning member 10 comprises an insert which may be positioned within different areas of an article of footwear. Accordingly, although cushioning member 10 is shown as being positioned within a midsole in FIG. 5, it is to be understood that cushioning member 10 may readily be positioned within a cavity f ormed within an outsole, an insole, or within a sockliner disposed within the upper. When positioned within an outsole, cll~h;r,n;n~ member 10 may be visible from the ~t~r; r,r of the shoe. Purther, because rllch;r-n;n~ member 10 comprises an insert, it will be appreciated that the shoe in which it is Wo 95/20332 2 1 8 ~ 9 q 8 PCrlUS94100895 incorporated may be constructed so that rl7qhlr,ning member 10 is readily removable and may easily be replared with another rllqh;nnin~ member Accordingly, different rllqh;nn;ng members can be inserted lal~r~nr~;ng upon the physical characteristics of the individual and/or the type of activity for which the shoe is intended .
Further, although FIG. 5 shows moderator 88 as comprising part of a 80rk~; n~r, ' tnr 88 may comprise any structure that results in a relatively stiff "plate~ ~al;qrng~ above rllqh;nn;n~ member 10. In fact, it is preferred that a tr,r 88 and cradle 104 be ;ntejr~l or unitary with one another. FIGS. 17-19 show one possible construction of this: '; . In FIGS. 17-19, ' ~ tnr 88 is shown ag being ;nte~r~1 with or comprising top surface 106 of cradle or midsole 104. In this regar;d, rather than having a complete cavity formed within midsole 104, ~' tnr 88 serves to form a partial cavity or reservoir 139 within the bottom ~3urface 140 of midsole 104.
Mnrlf~rntnr 88 further serves to create 81ightly raised areas 152 within top surface 106 of midsole 104 adjacent the forefoot and heel areas thereof. Partial cavity or l~:Sdl vuir 139 comprises a first or heel chamber receiving area 146, a second or forefoot chamber receiving area 148, and a third or ,- : r;!lt; nn chamber receiving area 150 . Reservoir 139 receives r-lqh;r,n;ng member 10 of the present invention. Similar to complete cavity 138, partial cavity or reservoir 139 forms an interior si~ ll 142 within midsole 104. In this _'; , it is preferred that the top surface of the outsole of the article of f ootwear also include a gmall ; n a~ntat; rn or cavity for receiving communication cha~ber 58. It 35 will be appreciated that the preferred integral - 'Ar~tnr and cradle i8 relatively simple to r-n11f-ct-1re, and increageg the simplicity of the present invention by -1 ;minAting the need for a sockliner or other separate aArSt;nA; mean5-As previously indicated, directional partitions 34 may be incorporated within ~ ch;~An;ng member lO, although they need not be. If incorporated, direct;A~nAl partitions 34 can help ~- ~ te for the problem of pronation, the natural tendency of the foot to roll inwardly af ter heel impact . During a typical gait cycle, the main distribution of forces on the foot begins adjacent the lateral side of the heel during the Dheel strike" phase of the gait, then moves toward the center axis of the f oot in the arch area, and then moves to the medial 8ide of the forefoot area during "toe-off . " Direct;~nA1 partitions 34 can be incu ~oLc.ted within c11Ah;nn~n~ mem~ber lO to ensure that the air flow within cllAh;~n;ng me~ber lO
complements such a gait cycle. Referring to FIGS. l, 4A and 5A, it has been previously noted that directional partition 34 within forefoot cham~ber 42 AA8F~nt;Al ly divideg the cham~ber into two regions:
medial tArAsll region 54 and outer metatarsal region 56. When air is forced into forefoot chamber 42, direct;~A,nAl partition 34 directs the majority of the air into medial metatarsal region 54, the region where the most impact forceg will occur. .~i;m;1;3rly, when air is forced into heel chalr~ber 26, dire~~t;~AnAl partition 34 formed therein ensures that the air will enter lateral heel region 38 first, as that is the region which will receive the greatest impact f orces during heel strike.
In addition to the above-noted changes, it will be readily appreciated that t~e number of chamAbers of Wo ssno332 2 1 8 1 9 9 8 Pcrruss4loosss cushioning member 10 may also be Yaried For e~Qmple, a second forefoot chamber 154, second heel chamber 1~6 and second ccmmunication chamber 158 may be provided, such as disclosed in FIG 20, such that cushioning s member 10 has two cl~hi nn; n~ systemg which function independently of one another. AltOEnatively, uu~, intercnnn~rtPrl ~-llch;nn;n~ may be provided, such as shown in FIG. 21. In the - '; t of FIG. 21, ~llqh;on;n~ member 10 would provide amultistagen ~llch;nn;n5, wherein the different would , t:88 in sF~ nre through the gait cycle .
An alternative ' '; - would include valve means ~; qpos~d adjacent c =nication chamber 58, in order to allow the flow rate to be adjusted. Another '' , shown in FIG. 21, would be to provide cl~h;nn;n~ member lO with at least two communication ~' ' , with each chamber 1nrll1~1;n~ an ;nt.~r;nr check-valve 160. Check valves 160 could simply comprise nl; ing means formed within, ;~tinn In such a construction, each c ; ~ At; nn chamber would be a one-way chamber such that air could only flow in one direction therethrough. FIG. 22 shows such an ' -'; , wherein fluid flows from heel chamber 26 to forefoot chamber 42 through first CQmmunication chamber 58, and from forefoot chamber 42 to heel chamber 2 6 via second ~ r~ t; nn chamber 158 . The air flow in this ~ lorl; could thus be directed such that it mimics the typical gait cycle discussed above. Further, one of the ~ ' c~t; nn , ' ' could include; ~ e means which provides laminar air flow, while the other communication chamber could include impedance means to provide turbulent air f low .

Wo95120332 2 1 8 1 998 PcrlUS94/00895 Although three differently-shaped impedance means are shown in the il r~ ~ ying drawings, other shapes will also serve to provide support and rll~h;~An;ng to the cushioning member of the present invention. The shape of; "Ac~nr- means 74 will directly affect the velocity of the air as it travels within cushioning member 10, and will therefore also affect the Reynold' s Number of the air flow within cushioning member 10. As previously alluded to, the Reynold' s Number, based on Reynold' s Tr~nAqpr~rt Theorem, is a tool which i8 used to flet-ArminA which phase or type of air flow is present in a qrAc~;f;ed system. The Reynold's Number is a lln;tlAq,q Ilumber which allows one to understand which pha8e of air flow is present in a ~ystem, by comparing the avalue" of the air flow to a predetArminpd number. For a smooth pipe, it is widely ~cc~rtA~g that air flow having a Reynold's Number below 2100 constitutes laminar fl,ow, where the Reynold's Number is defined by ~e = pD Air flow having a Reynold' s Number between 2100 and 4000 is generally cA,nq;rlAred transitional flow, and anything over 4000 i A r ~ n q; ~1 _ red t o b e t l ~ rh I 1 n t f l o w .
The mass flowrate of air within the r-lqh;An;ng member of the present invention is ~ upon the velocity of the heel strike (in the case of air travelling from the heel chamber to the forefoot chamber). Further, the 8ize and structure of the -- r_ mean8 of the present i~vention directly affects the impulse forces exerted by the air moving withi~ the ~` ' of the cushioning member. With a given flowrate, the size and structure of the ;, ?~ ~r_ means will dramatically a~fect the velocity of the air as it travels through the; ~ nre means.
Specifically, as the cross-sectional area of the ;, r_ means becomes smaller, the velocity of the wo 95l20332 2 1 8 1 9 9 8 PC~US94/00895 air flow becomes greater, as do the impulse forces felt in the ~orefoot and heel chambers As discus3ed herein, in the preferred embodiment of the present invention, ambient air is disposed within ~ ch;nn;n~ member lO. However, in an alternate '; of the present invention, pressurized air may be disposed within cl~h;nn;n~ member 10. For example, in order to keep forefoot and heel chamber6 42,26 slightly convex, a slight !2L~:bbULG
(apprnYi~-t~ly 1-~ p8i) may be introduced in to ch; nn; n~ member 10 when sealing the member closed .
Further, it will be appreciated that other fluid mediums, ; n~l llrl; n~ liquids and large l e~ ~l e gasaes, may be disposed within rl7~h; nn; n~ member lO and provide the desired support and r~ h; nn; n~ thereto .
If a fluid medium other than ambient air i5 used, the structure of the ; ~ means may be modif ied in order to effectively provide the ~h~r~rt~r of fluid f low desired .
It is ~nt;c;r~ted that the ,~)L~feLL~:d G ' ';
of the cll~h;on;n~ member of the present invention will find its greatest utility in athletic shoes (i.e., those ~ n~d for walking, hiking, running, aerobics, h;~k~th~l 1 and other athletic activitieg) . However, the c~l~h; nn; n~ member is also suited to provide h;~n~-Pf9 ml~h; nn; ng when incorporated within other types of fo~otwear, including formal "dress" shoes.
me preferred '; was chosen and described in order to best explain the pr;n~;rll~ of the present invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various ' ~ and with various modifications as are suited for the particular use Wo 95/20332 2 1 8 1 9 9 8 PcrluS94100895 ~ nt~nl~ted It is ;n~PnflPfl that the scope of the invention be defined by the claims i~rrPnrlPfl hereto

Claims

What Is Claimed Is:

1. An article of footwear comprising:
a sole;
a resilient cushioning member containing air at ambient pressure disposed within said sole, said cushioning member including a first chamber, a second chamber, and a communication chamber connecting said first chamber and said second chamber, said communication chamber having an average cross-sectional area which is less than the average cross -sectional area of both said first chamber and said second chamber; and impedance means for restricting the flow of air between said first chamber and said second chamber disposed within said communication chamber and having an average cross-sectional area less than the remainder of said communication chamber.

2. The article of footwear of claim 1, wherein said sole further comprises a midsole having a cavity portion, and wherein said cushioning member is disposed within said cavity portion of said midsole.

3. The article of footwear of claim 1, wherein said sole further comprises an outsole having a cavity portion, and wherein said cushioning member is disposed within said cavity portion of said outsole.

4. The article of footwear of claim 1, wherein said sole further comprises an insole having a cavity portion, and wherein said cushioning member is disposed within said cavity portion of said insole

5. The article of footwear of claim 1, further comprising a sockliner having a cavity portion disposed within an upper, and wherein said cushioning member is disposed within said cavity portion of said sockliner .

6 . The article of footwear of claim 1, wherein said cushioning member is formed of a blow-molded elastomeric material,

7. The article of footwear of claim 1, further comprising a moderating member disposed above said cushioning member for diffusing impact forces upon the cushioning member and providing support to a foot of a wearer.

8. The article of footwear of claim 7, wherein said moderating member comprises a material having of a Shore A hardness of 75-95 or Shore C hardness of 55-75 .

9. The article of footwear of claim 7, wherein said moderating member and said sole are integral with one another .

10. The article of footwear of claim 1, wherein said sole further comprises a heel portion and a forefoot portion, and wherein said first chamber and said second chamber are disposed adjacent said heel portion and said forefoot portion, respectively.

11. The article of footwear of claim 1, further comprising flexure grooves disposed on said second chamber.

12. The article of footwear of claim 1, further comprising a partition disposed within one of said first and second chambers for altering the direction of the air flow within said cushioning member.

13. The article of footwear of claim 1, wherein said impedance means is substantially hourglass-shaped.

14. The article of footwear of claim 1, wherein said impedance means is substantially "z"-shaped.

15. The article of footwear of claim 1, wherein said impedance means is substantially "w"-shaped.

16. The article of footwear of claim 1, wherein said impedance means is substantially "s"-shaped.

17. The article of footwear of claim 1, wherein said cushioning member further comprises an upper portion and a lower portion, said upper portion and said lower portion being mirror images of one another, such that said cushioning member may be readily disposed in either a left shoe or a right shoe.

18. An article of footwear comprising:
a sole having a heel portion, an arch portion, and a forefoot portion;
a cavity portion formed within said sole extending substantially from said heel portion to said forefoot portion;
a non-permeable, resilient first chamber containing ambient air disposed within said cavity portion adjacent said heel portion, said first chamber having an upper surface, a lower surface, a lateral side surface and a medial side surface;
a non-permeable, resilient second chamber containing ambient air disposed within said cavity portion adjacent said forefoot portion, said second chamber having an upper surface, a lower surface, a lateral side surface and a medial side surface;
a non-permeable communication chamber containing ambient air disposed within said cavity portion adjacent said arch portion, said communication chamber connecting said first chamber and said second chamber and having an upper surface, a lower surface, a medial side surface and a lateral side surface; and impedance means disposed within said communica-tion chamber and having an average cross - sectional area which is smaller than the average cross-sectional area of the remainder of said communication chamber, wherein said impedance means restricts the flow of air between said first chamber and said second chamber and provides enhanced cushioning to said article of footwear by controlling the velocity at which the air moves between said first chamber and said second chamber .

19. The article of footwear of claim 18, wherein said cushioning member is formed of a unitary piece of blow-molded elastomeric material.

20. The article of footwear of claim 18, wherein said impedance means increases the velocity and turbulence of the air as it moves between said first chamber and said second chamber.

21. The article of footwear of claim 18, wherein said communication chamber is sized and shaped to provide turbulent air flow between said first chamber and said second chamber when the weight of a wearer applies downward pressure to said first chamber.

22. The article of footwear of claim 18, wherein said communication chamber is sized and shaped to provide laminar air flow between said first chamber and said second chamber when the weight of a wearer applies downward pressure to said first chamber

23. The article of footwear of claim 18, wherein said communication chamber is sized and shaped to provide transitional air flow between said first chamber and said second chamber when the weight of a wearer applies downward pressure to said first chamber.

24. The article of footwear of claim 18, further comprising ridges disposed on said upper surface and said lower surface of said communication chamber.

25. The article of footwear of claim 18, wherein the vertical distance between said upper surface and said lower surface of said second chamber is less than the vertical distance between said upper surface and said lower surface of said first chamber.

26. The article of footwear of claim 18, further comprising a moderating member disposed above said cavity portion for diffusing impact forces upon said cushioning member and providing support to a foot of a wearer.

27. The article of footwear of claim 26, wherein said sole further comprises an upper surface and a lower surface, said cavity portion is formed within said lower surface of said sole, and said moderating member comprises said upper surface of said sole.

28. An article footwear comprising:
a sole;
a resilient cushioning member containing pressurized air disposed within said sole, said cushioning member including a first chamber, a second chamber and a communication chamber connecting said first chamber and second chamber, said communication chamber having an average cross - sectional area which is less than the average cross-sectional area of both said first chamber and said second chamber; and impedance means for restricting the flow of air between said first chamber and said second chamber disposed within said communication chamber and having an average cross-sectional area less than the remainder of said communication chamber.