CA1044587A - Support apparatus - Google Patents

Abstract

Abstract This apparatus for supporting a human body for improved blood circulation comprises a frame, a pair of endless flexible belt assemblies having transverse roller members, means for mounting the belt assemblies on the frame to form laterally juxtaposed body support spans each consisting essentially of an upper stretch of the roller members of a belt assembly, means for moving the belts to cause the roller members to move along the body support span of each belt assembly, and track means for supporting at least some of the roller members of the laterally juxtaposed body support spans in an angular position toward a Y-shaped relationship for a partially cradling body support effect.

Description

S8~
SUPPORT APPARATUS
- Specificatlon This inventlon relates to apparatus for support-ing a human body for lmproved blood circulation, e~peclally to ~acilltate blood movement through those tlssues pressed by the body against the apparatus.
Invallds and others who remain at rest ln one posltion for a long period Or tlme are apt to develop sores or ulcers on those portlons o~ thelr body bearing the lO body welght. Nature blesses the average lndlvidual wlth an excellent nervous system which prompts hlm to shift hls rest posltion rather frequently, whether that rest posltlon is one of sltting or lying down. Frequent shifts Or posltion facllitate caplllary blood movement through tissues ln those portions Or the body released by a shift o~ posltion rrom bearing the body's welght. Thls in turn saves the average individual from the development of sores or ulcers ln those portions. But paraplegics and others similarly afrll¢ted are elther inaapable Or shlrtlng posltlon or 20 forget to do so because no nervous system warnings Or ' dlscomfort are experlenced.
Normal cellular metabollsm as effected by blood s movement through those tlssues compressed by the welght ,~
of a body at rest has been a much sought after goal. The sitting positlon is especlally troublesome because very llttle tlssue ~fat or muscle) extends between the ischial tuberosities and the s~in covering therefor. That tissue is normally severely compressed and starved of blood by ; the weight o~ a person who remalns stationary in a sitting 30 position. But, according to this invention, the movement

- 2 -Or blood through caplllaries of tissue sub~ected to compresslon by body welght is facilitated without a critical necessity ~or manually or otherwise shiftlng or eleva~ing, or in any way notlceably moving, the per~on who is in a resting position (whether sitting or lying down) on the apparatus. Optionally, the apparatus hereof may be ad~usted to effect notlceable movement o~ the person on it; but such 18 not ¢ritlcally necessary when practiclng the invention.
The apparatus o~ this inventlon i9 designed to support a human body in a partially cradled and varied pressure manner to faailitate the movement of blood through those tissues Or the body as pressed by the weight Or the body against the apparatus. This apparatus comprlses:
(1) a frame;
(11) a palr of endless flexlble belt assemblies; each belt assembly compri~es a plurallty of transverse roller members arranged in substantially parallel relationshlp;
(ili) means for mounting each belt assembly on the frame so that each forms a body support span consisting essentially of an upper stretch of roller members of the belt assembly; the body support span of one belt assembly is laterally ~uxtaposed to the .
. body support span of the other belt assembly;
(iv) means for moving each belt assembly to cause .
the roller members thereof to move in sequence along the length of the body support span formed by the belt assembly; thus, those tissues of a body as pressed by its weight against a body _ 3 _ .

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~a4/i5~37 support span are sub~ected to a stroking actlon Or alternate pre~sure and release Or pressure as erfected by the movement Or the roller members; and (v) track means for supporting at least a portlon Or the roller members Or one body support span ln an angular relatlonship to at least a portlon Or the roller members Or the other span at least durlng tlmes when the welght Or a body rests ln part on each ~uch portlon; thls angular rélatlonshlp i8 such that the medlal ~uxtaposed ends Or the roller members Or each such portlon are relatlvely more displaced downwardly than the outside lateral ends thereor; thus, a body restlng in part on each body support span Or the apparatus i8 partially cradled in its position Or rest, The roregoing and other features and benefits Or the invention wlll rurther be explained and descrlbed wlth the aid Or a drawlng, made a part hereor, whereln:
Flgure 1 18 a schematic perspectlve vlew Or a support platform rOr a human body; . .
Flgure 2 ls a schematlc top plan vlew, partially `
broken away, Or the structure Or the support platform wlth its flexible cover removed and with underlying parts omitted rrom the vlew so as to permit clarity in the showing;
Figure 3 ls a schematlc cross sectional vlew taken on line 3-3 Or Figure 2 and particularly illustrates the angular relationship Or roller members Or the apparatus;
Figure 4 ls a schematlc cross sectlonal view, partially broken away, taken on llne 4-4 Or Flgure 2, and ; . .

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1~J4~58'7 particularly lllustrates a track means and cooperatlvely associated elements o~ the apparatus;
Figure 5 is a schematic cross sectional view, partially broken away, taken on line 5-5 of Flgure 4, and particularly illustrates features Or the system for movlng the roller members Or the apparatus;
Flgure 6 ls a schematic perspective view of a wheelchair equipped with a seat according to the lnventlon;
Figure 7 ls a schematlc plan vlew showing reatures Or an endless llnk chaln useful for the lnventlon; and Flgures8 through ll, lncluslve, are schematlc vlews of an alternate seat member of thls inventlon--Flgure 8 belng a perspectlve view, and Figures 9 through 11 being sectlonal views (wlth parts bro~en away) each taken along llnes Or lmmediately preceding rigures as marked on the drawlng, wlth Figure ll additionally lncluding a section through a buttocks The showing in Flgure 1 1~ intended to be illustrative of a platform lO for supporting a human body whether that platform comprlses the seat of a chair, or the support surface of a bed or any other structure. The ~ teachings hereln are useful ln such envlronments; but the .. :
seat of a chair will most frequently receive partlcular attentlon in describing basic elements and arrangements characterlstlc of the lnventlon.
Under most conditions, the platform lO is covered with a flexible sheet or layer of material--such as a layer of plastlc fllm or leather or cloth. The covering ls especlally desirable from the standpoint Or provlding an ~0 easily cleaned surface~ Thick padded cover materials are - ........ . .
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iV4~87 not deslrably e~ployed, ror they interfere wlth the erfec-tlveness Or the selectlve appllcation and release Or pres-sure as herelnsrter discussed.
Rererring particularly to Figure 2, the frame for the support plat~orm suitably comprises girders in the -~
nature Or panels or narrow strlps Or rlgid material. These may be rormed Or plastic, wood, or metal; but aluminum is prererred. Illustratively, slde girders ll and 12 are unlted to a front or head girder 13 and a rear or root girder 14 in any suitable manner to rorm a complete periph-eral or perlmeter rrame. A medial girder or panel 15, intermediate the side panels, suitably extends rrom the rrOnt 13 to rear 14 panel and divides the structure into two main sections or parts, which preferably are about equal in size. The perimeter rrame may vary in length, as desired ror its ultimate use~ and is sultably mounted on known rrame elements Or a chair or bed in a manner to rorm a sest or bed, as deslred.
A ¢ontlnuous or endless rlexlble belt assembly ls mounted ln each part Or the rrame structure separated by the medial girder 15. These belt assemblies are broadly deslgnated by the numerals 16 and 17 in the drawing. Slnce both belt assemblies may be and preferably are substan-tially identlcal, emphasls in describlng thelr nature will be concentrated on the belt assembly 17 at the right in Figure 2.
Belt assembly 17 comprises a plurality Or trans-verse roller members 18. Rollers 18 are arranged in sub-stantially parallel relationship at intervals of spaced 0 character along the entire extent of the composite ~ 4~587 endless belt 17. A proximate spaced relatlon~hip between roller members is preferred in that it gives an lndlvldual resting upon the roller members the sensation that he ls supported by a platform even though there are ~paces between the roller members. Generally, the wldth of spaces between roller members 18 will not normally be greater than approxlmately the diameter of the roller members; but greater spacing may be employed where it is not ob~ection-able ir a person restlng on the apparatus ls 8ub~ected to notlceable up and down movement. Usually the spaclng wlll be about that ~ust sufflcient to permit each roller to freely rotate without abutting agalnst any ad~acent roller at any point along the travel of the belt assembly. While each roller membe~ is mounted for free rotation about its axis, suitably on roller bearings, there is no need for powered rotatlon of the roller members. Further, the pre-ferred roller members are substantially cylindrical; but rollers of varied radial or longitudinal contour may be em-ployed, if desired. For maxlmum benerlt in term~ of ~acil-ltatlng healthy blood movement, roller members formed outof stlff or rigid materials (such as wood, metal or hard plastics) should be used in preference to those formed out of resilient or soft materials. The diameter of preferred roller members should be at least about one or two centime-ters up to about ~our or five centimeters. Rollers of about three centimeters diameter give excellent results in terms of comfort and in terms of facilitating blood movement.
The exact structural details for a composite endless belt assembly having freely rotatable tran~verse roller members may vary. Illu6trat1vely, each belt assembly .

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16 and 17 comprises a palr Or endless link chains between which the roller members are mounted. The pair Or link ~-chains 19 and 20 carry the rollers 23 for the belt assembly 16; and the pair of chains 21 and 22 carry the rollers 18 for belt 17. These link chains may take the character Or an ordinary blcycle chaln. Each link (see Flgure 7) ls ;~
separated and consists Or two parts 24 and 25; 26 and 27;
28 and 29. Llnks overlap and are unlted by plns 30 and 31.
A ¢yllnder or spaclng sleeve or enlargement 32 and 33 on each pln serves to separate and connect the two parts Or each llnk. Preferably, cyllnders 32 and 33 exhlbit llttle resistence to rotation about thelr pin axls, and 3erve as cooperating means ror contact en~agement with and movement over a track gulde, as will be explained. Each roller 18 and 23 is suitably rlxed between endless link chains by ex-tending the shaft of a pin connector and using that shart as the axls ~or the roller.
Each composlte rlexlble belt assembly 16 and 17 ls mounted on the frame so that each rorms a body support ~pan. A body support span conslsts essentlally Or an upper stretch Or the roller members of a belt assembly; and ln Flgure 2, the body support spans are formed by the visible rollers there shown. The body support span of one belt assembly16 is laterally ~uxtaposed to the body support span Or the other belt assembly 17. This places the medial ends ~ (nearest medialgirder 15) of the roller members 23 Or one -~ span ln medial ~uxtaposed relationship to the medial end Or - the roller members 18 Or the other span. (But the rollers ; Or one span need not be ln perfect end-to-end relationshlp with the rollers Or the other ~pan; they may be in staggered ~ 8 -..... : , ...................... : -:. . .
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1t~44587 relatlonshlp, or wlth alternate rollers omltted, lf de-slred.) The spaclng dlstance between the spans Or roller members at the medlal portion 15 Or the apparatus should be kept to a mlnimum consistent wlth the necessary strength of structural features and the support contact to be experienced by a person on the apparatus. Generally, the medial spacing should not eXceed approximately twelve centimeters ~five lnches); and preferably, lt ls no greater than about elght or ten centlmeters. Very deslrable it is to employ the smaller spa¢lng dlstances (e.g., elght centlmeters or less) between the end medlal portions of the Juxtaposed rollers.
However, it ls not crltical to maintain the spaclng dlstance between the medlal ends at a level below that Or the average spacing between lschlal tuberoslties o~ indlviduals The angularlty ror the rollers, as wlll be explalned further below, supports a sittlng person to some extent alone slde portlons of hls buttocks. Thls ls characterlzed herein as a partlally cradled support. It relleves the bottom end o~ the ischlal tuberosltles from receiving the whole welght Or the mass Or one~s body as conventionally experlenced when sittlng on a flat sur~ace.
Referring partlcularly to Flgures 2 and 4, an illustratlve non-llmitative mounting for the end-less belt assemblies 16 and 17 will be discussed. The endless link chalns of each composlte belt assembly are suitably entrained about sprockets carried on shafts 34 and 35 near the front and rear of the frame il-lustrated in Figure 2. Shafts 34 and 35 are mounted for relatively free rotation in side girders 11 and 12 and medlal girder 15. Illustratively, the endless link chain 21 is shown in Figure 4 to be entrained about _ g _ ' `
. ' . ' sprockets 36 and 37. Other sprockets on sharts 34 and 35 for chains 19, 20, and 22 are Or simllar nature. The sprocket wheels suitably are rigldly rlxed to the shafts 34 and 35 so that rotation Or one sprocket wheel wlll effec-tlvely cause rotatlon of the shart carrylng lt as well as all sprocket wheels along that shaft. Further, the lnter-lo¢king Or the endless llnk chalns on the sprocket wheels efrectlvely causes the sprockets on shart 34 to rotate when the sprockets on shart 35 are rotated;,and vlce versa.
The power for such rotatlon ls transmltted through the endless llnk chalns.
While the sharts 34 and 35 are lllustrated as unitary sharts whlch extend completely across the frame of the apparatus, lt ls also contemplated that the sha~t carrylng the sprockets ror one composlte endless belt as-sembly, for example, belt assembly 16, may be separate and lndependent from the shart carrylng the sprockets for the other belt assembly 17. Further, sepa~ate and lnde-pendent sha~ts may be tllted or placed at a positlon Or angularlty to each other 80 as to cause the entlre length o~ a body support span formed by the upper stretch Or a belt assembly to be sloped downwardly toward the medlal portlon 15 of the apparatus.
The mountlng Or the endless belt assemblles 16 and 17 in the frame Or the apparatus is normally accom-plished ln a manner to permit the roller members of the belt assemblies to be shifted ln position with respect to the basic elements Or the frame. In other words, the end-less link chains are not mounted in a taut condition.
Because of the non-taut or slack mounting condition, the ~ 4~587 lower stretch o~ an endless belt assembly (see rollers 38 in Figures 3, 4 and 5) would be expected to sag downwardly.
Thls can be prevented by u~lng a retalnlng means, such as a strip or band 39 extending from the front 13 to rear 14 glrders, over which the lower roller members roll as they travel along their lower stretch. Alternately, the link chains may be supported by a ledge or ~trlp along thelr -lower stretch Or travel.
To malntain the upper stretch Or non-taut Plexi-ble endless belt assemblles ln a positlon to form a com-fortable body support span, and to control thelr posltlon `;
as the welght of an lndlvldual i~ applled thereto, requlres speclal track means between the ends Or the upper stretch formlng the body support span. Illustratlvely, end sprocket wheels (such as wheels 36 and 37 in Figure 4) sultably perform a support runction at each end Or the mounted belt assemblies; but intermedlate those end sprocket wheels, track means Or some sort 1~ needed for supportlng the upper stretch Or rollers Or the ~lexible belt assembllesln proper positlon to accompllsh the lm-proved supportlng Or a human body as taught hereln.
Referrlng to Flgures 3 and 4,an lllustratlvetrack - means at the medial ~uxtaposed slde, or lnslde edge por-tlon, Or the belt assemblles 16 and 17 sultably comprlses contoured rall members 40 and 41. The contour of theæ rail members ls lllustrated more partlcularly in Flgure 4, where ` a slde vlew of rall 41 ls shown. To be observed ls that -~ the upper edge Or rail 40 serves as the gulde rail or sur-~ace over whlch the medial endless link chaln 20 ls guided in its movement; and the upper edge oP rail 41per~orm~ llke -- 11 -- .

11)9~587 functlon for link chaln 21. The upper edge of the track ralls suitably ls slanted or sloped toward the medlal part Or the apparatus; and the cyllndrical spacer elements tsee --32 and 33 ln Figure 7) of the llnk chaln~ cooperatlvely rest and slide, or even rotate, ~s the llnk chalns trans-verse the length Or the rail members. , Especlally to be noted (see Flgure 4) is the varied helght and the depressed path or contour for at least a portlon of the medlal tra¢k 41. (Medial track 40 is essentially ldenti¢al to tra¢k 41, but a mirror image Or it as mounted on the apparatus.) Lateral or outslde edge tracks 42 and 43 tsee ~lgure 3) may or may not be shaped to exhlblt a slmllar contour to that lllustrated for track 41. Whether or not the lateral track members 42 and 43 are slmllar ln general shape to tracks 40 and 41, the relatlve helght locatlon for tra¢ks 42 and 43 wlll be above that for at least a portlon of the length of tra¢ks 40 and 41. Thus, the arrangement o~ the tra¢k members 40, 41, 42, and 43 is su¢h as to ¢ause at least some Or the rollers (su¢h as the rollers marked 44 and 45 ln ~igures 2 and 3, and the roller marked 44 in Figure 4) to assume an angular relatlonshlp to each other.
Thls angular relationæhlp ls such that the medial ~uxta-posed ends Or at least some of the roller members are rel-atively more dlsplaced downwardly than the outslde lateral ends of those rollers. In this manner a partially cradled support ~or a body ls formed. The endless llnk chalns 19, 20, 21 and 22 cooperatlvely move or slide upon the upper edge Or the structures characterized as the tra¢k means as the composlte belt assemblies are moved.

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` '~ ' ~' ' ' ' -Sultably, the track members 40, 41, 42, and 43 are mounted or flxed ln spaced condltion to the rrame glrders ll, 15, and 12 by plns 46 or slmilar rastener elements.
As lllustrated ln Flgure 4, the medlal glrder 15 ~ -ls sultably contoured or shaped so that lt does not extend ~ -upwardly beyond the approxlmate helght Or roller members at the medlal portion Or the apparatus. Indeed, preferred lt ls to malntaln the helght Or medlal glrder 15 below the height of the rollers at thelr medlally lnward ends.
It ls emphaslzed that a slgnlrlcant feature Or the track means ls that Or causlng a condltlon Or angular-lty between laterally ~uxtaposed roller members along at least some part Or the body support spans formed by the composlte belt assemblles. However, thls condltlon Or angularlty (such as lllustrated ln Flgure 3) prevails prl-marlly when the welght Or a body rests ln part on esch body support span Or the apparatus. It may prevall at all times, but it must prevail when a body 18 resting ln part on both support spans. In other words, the condltlon Or angularlty may dlsappear when no welght presses the upper stretch Or the belt assemblles agalnst the track means (such as track members 40 and 41). or course, permanent :angularlty may be bullt lnto the apparatus by tilting each -:
body support span toward the medlal portion Or the ap-paratus, as noted hereinabove. Greater comrort ls gained, however, when the rollers intermediate the ends of a body support span are flexed or torqued into a condition Or angularlty dlrferent from a relatlvely horlzontal angular relatlonshlp between the roller members at termlnal end '~"''~`' ' ' ' ' ' ' ''' ' ' ' -~`

portlons Or the ~uxtaposed support spans. Thls ls espe-clally true when the apparatus i8 deslgned to be used as a seat for a chalr. It ls more comfortable to rest one's thlghs on a relatlvely flat or horlzontal surface than on sloped surraces tendlng to force one's thlghs together.
The sloplng Or the roller members, such as roller members 44 and 45, need not be especially great to cause a pronounced efre¢t Or comfort and freedom rrom the effect Or 3upporting the entire weight o~ one~ 8 upper body on one~s ischial tuberosltles. Even a slope as little as one degree rrom the horizontal for each ~uxtaposed roller can be useful to dlstribute some Or the welght away rrom direct impact on the ischial tuberosities~ Such a slope places the ~uxtaposed rollers at approximately 17~ to each other.
Slopes in excess Or 20 from the horizontal are unnecessary and not particularly comfortable. In most cases a slope from about 2 to 8 or possibly 10 rrom the horizontal will be employed; slopes Or such magnitude have a pronounced e~fect in terms of dlstributlng body weight away ~rom thin ; 20 tissue areas, particularly ~or the sitting individual, and are well within what might be called a reasonable comfort range. From a slttlng standpolnt, the angular relation~hlp contrlbutes toward dlstrlbution of the pressures for sup-port Or the body along the sides Or the buttocks.
A critical feature Or the invention is the fact that the composite belt assemblies 16 and 17 are moved by power means so that the roller members Or each belt assem-bly are caused to move in sequence along the length of the : body support span formed by the belt assembly. This move-ment Or the roller members more or-less sub~ects every ;. ~.

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portion of a person's body, as pressed by the person's weight against the support span, to a stroking actlon.
The stroking action is caused by the alternate support by a roller and lack Or support by a roller as it moves under-neath the person's body. It causes~ an alternate pressure and release of pressure on the portlons of the body in contact wlth the apparatus; and lt also forclbly moves blood through body tlssues stroked. Further, the fact that the support pressure i9 llmited to the portion of the circumference Or the roller member ln contact with the body means that the portions of the person's body between roller members are free of support pressure and can undergo capillary flow of blood. All of this contributes toward freedom from the development of sores and ulcers as a result of sitting or lying down ln a posltlon of rest on the apparatus for long periods of tlme. Both the cradling effect o~ the angularly dlsposed rollers and the movement orthose rollers play a part ln contrlbuting to healthy capillary blood rlow. ~he cradling erfect tends to di3-tribute support pressures on portions of the buttocks (orside ~arts of a prone body) where the tissue between bones and skin is relatively thick. Such tissue has a greater ablllty to take up blood than a very thin layer of tlssue.
The stroking actlon enhances relatlvely signiflcant blood movement in such relatively thlck tissues.
The power train for effectlng movement of the endless belt assemblles need not be of such ambltlous char-acter as to requlre special precautions agalnst power hazards. It might normally be expected that electrical motors of substantial power would be needed to effect the ';

1~4~587 necessary movement Or the endless belt assemblies rormlng the support structure Or the lnventlon. Surprlslngly, lt is possible to accompllsh satisfactory movement of the endless belt assemblles (whlch exhlbit relatively low frlc-tlonal reslstance to movement) by uslng a battery powered electrlcal motor requiring very llttle voltage and amper-age--for example~ no more than about ten volts and no more than about one ampere. In short, a suitable power or motive source may be sèlf contàlned as part Or the devlce, re-quire no grounding, and yet be effecti~e for rellable oper-ation for long periods such as 12 or 16 hours or more.
Varled mechanical arrangements for power input may be em-ployed. Each endless belt may be mounted for movement (slower or raster or in reverse directlon) independently of the other. The power lnput to each can vary. A suita-ble arrangement for the device lllustrated is as follows:
Power rrom a rapidly whlrling ,small electrical motor 47, energized by batteries ln a battery recess 48, is fed through a eear speed reductlon system 49 to a main drlve shaft 50 (sultably mounted on a dependlng ear part 51 of the medlal brace 15). Drive shaft 50 carries the main drive sprocket 52 which engages one of the endless llnk - chalns (such as chain 21). Cross members such as cyllnders 32 and 33 (see Flgure 7) of the llnk chain are maintained in engaged entrainment with recesses in the sprocket gear 52 by a foot cam 53 beneath whlch the endless llnk chain is forced in lts travel. Cam 52 ls fixed to the medlal girder or brace 15 of the apparatus.
The gear reduction system 49 suitably slows the effectlve rate of movement of the endless belt assemblies ` , , :

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1~)4~587 16 and 17 to that whlch is barely perceptlble. A rate as low as a centimeter per mlnute can be satlsractory to pro-vlde the blood movement results espoused hereln. Even lower rates Or movement may be ~atlsractory to save some persons from sores and ulcers as they remaln essentlally statlonary ln a sittlng or lylng positlon on the apparatu~.
Faster rates Or movement are also posslble ~although usually unnecessary); and rates o~ movement as rast as a ¢entimeter per halr minute, or even a centimeter per second may be used with success (but wlth concomitant increase o~
power consumptlon, which makes excessively rast movements undesirable). Even lntermlttent movement may be employed, ir deslred.
The essentlal polnt to recognize is that the movement Or the roller members Or each belt assembly ls accomplished along the support span rormed by the belt assembly; and thls movement ls at least sufriclent to cause alternate application and release Or support pressures on each point o~ the body pressed agalnst the support span.
The apparatus Or the invention is especially userul as a seat member. Truckers and others who slt and drlve long dlstances can galn benerlts from sittlng on a seat rormed as taught hereln whlle drlvlng those dlstances.
Invallds wlll flnd the teachlngs hereln especlally valuable ~or wheelchairs. A wheelchair such as lllustrated in Figure 6 sultably comprises a seat member, as taught herein, mounted on a frame carrled by maln drlve wheels and havlng plvotable stabillzer wheels. Such chalrs also lnclude a back member and foot rests. Frequently the maln drive wheels are hand powered through hand wheels, as illustrated.

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An especially userul sest member ls lllustrated ln Flgures 8 through 11. The laterally ~uxtaposed belt assemblles, ~ormed of a plurallty of rollers 54 and 55, are moved by motor 56 actlng through a drlve llnkage. The drlve llnkage comprlses gear reductlon ~ystem 57 whlch rotates a drive shaft 58 carrylng a worm gear. A drlve gear 59 ls rotated by the worm gear Or the drlve shart; and gear 59 ln turn rotates a cross shaft 60 carrylng the sprocket wheel~ (e.g., wheel 61 ln Flgure 10) which en~a~e and move the endless link chalns 62, 63, 64 and 65. To be noted 1~ that two medlal girders 66 and 67 extend in spaced relatlon~hlp ~rom each other rrom the rront to the back o~ rear part o~ the base rrame. Between these glrders (and therefore between the belt -assemblies comprlsed o~ rollers 54 and 55) ls located the motor 56 and the drive linkage. Further, a battery package 68 ror energlzlng the motor ls also located between the spaced medlal ~lrders 66 and 67. ~or course, the motor, drlve llnkage, and also the batterypackage, may be posltloned laterally or anterlorly or beneath the ~uxtaposed belt as~e~blleR, lr deslred,) The actuatlon Or mo~ement Or the belt assemblles ls sultably accompllshed ln response to the weight of a body on the apparatus. Specifically, a pressure actuated switch 69 may complete the circuit ror the ~low Or electricity to motor 56 from battery 68 whenever switch 69 i~ closed as a result Or someone sitting on the apparatus. Medial contoured track 70, which supports the upper stretch 71 Or endless link chain 63 may be mounted on medial girder 67 for a limited floating ; relationship. For example, track 70 may be plvotally mounted at one end by bolt 72 to glrder 67 so as to permit slight - 18 _ --: -movement ~or the opposite end 73 Or track 70. At end 73 ls carrled the pressure element ror actuatlng swltch 69. The pivot movement rOr track 70 ls llmited by any sultable means, such as by the abutment of edges Or slot 74 agalnst lmmovable bolt 75 rlxed to glrder 67. The end 73 of track 70 ls biased, as by a sprlng 76, lnto a normally upward posltlon where swltch 69 remalns open.
Padded support members 77 and 78 are laterally ~uxtaposed outwardly ~rom each body support span formed by the rollers 54 and 55. These padded members 77 and 78 are sultably mounted on rigid or metal shelf members 79 and 80 which extend out~ardly rrom lateral elements Or the base rrame 90, Shelr members 79 and 80 may be used to rest the composite seat member on side brace elements of a chalr. Ir desired, a padded front support member 81 may be fixed along the front edge Or the composlte seat structure. To conceal and protect the motor 56 and the drive linkage, a removable cover plate 82 may be employed, SlmilarlyJ a removable cover plate 83 may protect the battery assembly 68. Any suitable thin flexible cover 84 tshown folded back in Figure 8) may be removably fastened over the composlte seat ~tructure ror appearance purposes or sanltary reasons.
As illustrated in Flgure 11, the weight Or a seated person ls supported by the apparatus at a slightly angular relationship to that ~latly under his ischial tuberosities T~e movement o~ the belt assemblies at such locations faclll-tates tlssue blood flow. The padded edges 77 and 7a under trochanters 87 and 88 contribute to a psychologlcal lmpression of comfort~ but do not apply signiricant pressures in those areas to interfere wlth sati~factory tlssue blood flo~J.
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~G~9~5137 Preferably, the movement of the roller members of the apparatus hereo~ is accompllshed rrom ~ront to back along the support spans Or a seat ~tructure (or foot to head ror a bed). Also, the rollers Or each span are pre-rerably moved in the same directlon; but they may be moved ln opposlte dlrectlons, lf deslred.
Whlle the invention has been des¢rlbed wlth partlcular rererence to speclflc structural detalls illus-trated in the drawlng, lt i9 to be recognized that varlatlons from the specirlc lllustrated ~tructural detalls are posslble wlthout departlng rrom the essentlal character Or the invention as set forth ln the appended claims.

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Claims (25)

That which is claimed is:

1. Apparatus for supporting a human body in a partially cradled and varied pressure manner to facilitate the movement of blood through those tissues of the body as pressed by the weight of the body against the apparatus, said apparatus comprising:
(i) a frame;
(ii) a pair of endless flexible belt assemblies, each said belt assembly comprising a plurality of transverse roller members arranged in substan-tially parallel relationship;
(iii) means for mounting each said belt assembly on said frame so that each forms a body support span consisting essentially of an upper stretch of said roller members thereof, said body support span of one said belt assembly being laterally juxtaposed to said body support span of the other said belt assembly;
(iv) means for moving each said belt assembly to cause said roller members thereof to move in sequence along the length of said body support span formed thereby, whereby those tissues of a body as pressed by its weight against a said span are subjected to a stroking action of alternate pressure and release of pressure as effected by said movement of said roller members; and (v) track means for supporting at least a portion of said roller members of one said span in an angular relationship to at least a portion of the roller members of the other said span at least during times when the weight of a body rests in part on each said portion, said angular relationship being such that the medial juxta-posed ends of those said roller members of each said portion are relatively more displaced downwardly than the outside lateral ends thereof, thereby to partially cradle a body resting in part on each said span.

2. The apparatus of claim 1 wherein said means for mounting each said belt assembly on said frame allows for flexible shifting of the path of movement by the belt assembly and the rollers thereof as the weight of a body is applied upon said body support spans.

3. The apparatus of claim 1 wherein said means for mounting each said belt assembly on said frame provides for slack and shifting of position of each said belt assem-bly with respect to said frame, and wherein a lower stretch of said belt assembly is supported against sagging down-wardly by retaining means.

4. The apparatus of claim 1 wherein said medial juxtaposed ends of said roller members of each said portion are adapted to be displaced downwardly from the lateral ends thereof a distance which places said roller members at an angle between 1° and 20° from the horizontal.

5. The apparatus of claim 1 wherein said angular relationship between said medially juxtaposed ends of said roller members of each said portion is an angular relation-ship different from that angular relationship formed between roller members at the end portions of said juxta-posed spans.

6. The apparatus of claim 1 wherein said track means comprises a rail member at the medial juxtaposed side portion of a said one belt assembly and wherein said one belt assembly comprises an endless link chain to which said roller members of said one belt assembly are affixed, said endless link chain being equipped with cooperating means for movement on said rail member.

7. The apparatus of claim 1 wherein said means for moving each said belt assembly comprises a self contained power source mounted on said apparatus.

8. The apparatus of claim 1 wherein said means for moving each said belt assembly effects movement of said roller members of each said belt assembly in the same direction.

9. The apparatus of claim 1 wherein said roller members of each said belt assembly are substantially non-resilient.

10. The apparatus of claim 1 wherein each said belt assembly comprises a pair of endless link chains between which said roller members are mounted, at least said link chains at the medial juxtaposed ends of said roller members being equipped with cooperating elements for movement along said track means.

11. The apparatus of claim 1 wherein each said belt assembly comprises a pair of endless link chains be-tween which said roller members are mounted for free rotary movement, and wherein said means for mounting each said belt assembly on said frame comprises sprocket wheels about which said link chains are entrained.

12. The apparatus of claim 11 wherein said means for moving each said belt assembly comprises a drive sprocket engaging a said link chain and wherein said drive sprocket is powered through a speed reducing gear by a motor energized by a power source mounted on said apparatus.

13. The apparatus of claim 12 additionally comprising a foot cam for maintaining said link chain engaged with said drive sprocket.

14. The apparatus of claim 1 wherein said means for moving each said belt assembly is actuated by the weight of a body supported on said apparatus.

15. The apparatus of claim 1 wherein said means for moving each said belt assembly comprises a motor and drive linkage mounted medially between said belt assemblies.

16. The apparatus of claim 1 additionally comprising padded support members laterally juxtaposed outwardly from each said body support span.

17. The apparatus of claim 16 wherein said padded support members are mounted on a shelf member extending outwardly from said frame.

18. The apparatus of claim 1 wherein said frame comprises a chair having a seat member and wherein said seat member comprises each said body support span.

19. The apparatus of claim 18 wherein said chair comprises a wheelchair.

20. Apparatus for supporting a human body for improved blood circulation, comprising a frame, a pelf of endless flexible belt assemblies having transverse roller members, means for mounting said belt assemblies on said frame to form laterally juxtaposed body support spans each consisting essentially of an upper stretch of said roller members of a said belt assembly, means for moving said belt assemblies to cause the roller members thereof to move along said body support spans thereof, and track means for supporting at least some of said roller members of said laterally juxtaposed body support spans in an angular position toward a V-shaped relationship for a partially cradling body support effect.

21. The apparatus of claim 20 wherein said means for mounting each said belt assembly on said frame allows for flexible shifting of the path of movement by the belt assembly and the rollers thereof as the weight of a body is applied upon said body support spans.

22. The apparatus of claim 20 wherein said means for mounting each said belt assembly on said frame provides for slack and shifting of position of each said belt assem-bly with respect to said frame, and wherein a lower stretch of said belt assembly is supported against sagging downwardly by retaining means.

23. The apparatus of claim 20 wherein said means for moving each said belt assembly is actuated by the weight of a body supported on said apparatus.

24. The apparatus of claim 20 wherein said V-shaped relationship obtains only when the weight of a body is supported upon said body support spans.

25. The apparatus of claim 20 wherein said V-shaped relationship obtains at all times.