Note: Descriptions are shown in the official language in which they were submitted.
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
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587
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
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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
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~ 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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58'~
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
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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
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1044587
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
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~ 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
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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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587
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
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587
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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1~4~S87 ~ :
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
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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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1~?4~587 :
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
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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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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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