U.S. patent number 3,717,376 [Application Number 05/068,306] was granted by the patent office on 1973-02-20 for furniture with body contour accommodating support system.
Invention is credited to Milton Lutchansky.
United States Patent |
3,717,376 |
Lutchansky |
February 20, 1973 |
FURNITURE WITH BODY CONTOUR ACCOMMODATING SUPPORT SYSTEM
Abstract
An item of furniture such as a bed or chair provides increased
comfort by supporting a body resting thereon with a distribution of
support forces which match the body's weight distribution while
simultaneously conforming to the contour of the supported body.
This is accomplished by supporting the body with a plurality of
spaced force means which are interconnected with a common force
transmitting means. The spacings of the force means, the individual
support forces provided by the force means, or both may be adjusted
to achieve the desired support force distribution. Changes in body
contour are accommodated by a movement of the force transmitting
means without changing the magnitudes of the support forces.
Inventors: |
Lutchansky; Milton (Dover,
NJ) |
Family
ID: |
22081723 |
Appl.
No.: |
05/068,306 |
Filed: |
August 31, 1970 |
Current U.S.
Class: |
297/284.1; 5/238;
297/60; 5/617 |
Current CPC
Class: |
A47C
31/123 (20130101); A61G 7/0573 (20130101); A47C
31/126 (20130101) |
Current International
Class: |
A47C
31/00 (20060101); A47C 31/12 (20060101); A61G
7/057 (20060101); A47c 003/00 (); A47c 025/00 ();
A47c 004/00 () |
Field of
Search: |
;297/284 ;5/60,91,186T
;248/399,400 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Gilliam; Paul R.
Claims
I claim:
1. An article of furniture for supporting a body resting thereon
with a preselected support force distribution and conforming
automatically to various contours of said body without changing
said preselected support force distribution comprising, in
combination:
a frame;
a support pad upon which said body rests, said pad having
flexibility in the direction of the longitudinal axis of said
body;
a first set of low friction pulleys mounted along said frame at
spaced mounting points; and
a second set of low friction pulleys mounted at spaced support
points along said pad corresponding to said mounting points and
providing support forces to said pad, said pulleys having spacings
therebetween related to said preselected support force
distribution; and
flexible cord means interconnecting said first and second sets of
pulleys and suspending said pad from said frame so that by a
redistribution of said cord means among said first and second sets
of pulleys said pad can conform to changes in said contour by
movement of said pad relative to said frame, said cord means having
substantially constant tension therein independent of said movement
so that said support forces remain constant thereby to maintain
said preselected support force distribution.
2. Apparatus in accordance with claim 1 wherein said pad comprises
first and second sections, said first section supporting a first
portion of said body including the trunk and head thereof, said
second section supporting a second portion of said body including
the hips and legs thereof;
said first and second sets of pulleys each comprises first and
second groups of pulleys associated with said first and second
sections, respectively; and
said flexible cord means comprises separate flexible cords
interconnecting said first and second groups of pulleys,
respectively, and connecting said first and second sections,
respectively, to said frame so that said first and second sections
function substantially independently of each other.
3. Apparatus in accordance with claim 1 including auxiliary support
means mounted to said pad between preselected ones of said support
points for providing additional support forces when said movement
of said pad at said preselected support points exceeds a
predetermined magnitude, said auxiliary support means including a
low friction pulley adapted to contact said flexible cord means
when said movement equals said predetermined magnitude.
4. Apparatus in accordance with claim 1 wherein said first set of
pulleys is mounted on sides of said frame extending in the same
direction as said longitudinal axis;
said second set of pulleys is mounted along edges of said pad which
lie in the same direction as said longitudinal axis; and
said flexible cord means includes separate cords interconnecting
said first and second sets of pulleys along said respective edges
and sides.
5. Apparatus in accordance with claim 1 wherein said pad includes a
plurality of support slats oriented substantially transverse to
said longitudinal axis and having spacings therebetween
substantially the same as said spacings between said support
points, said second set of pulleys being mounted to the ends of
said support slats; and
bridging means oriented transverse to said support slats and
connecting adjacent ones thereof when said spacing therebetween
exceeds a predetermined amount so that said pad is prevented from
sagging between said adjacent support slats.
6. Apparatus in accordance with claim 1 including weights affixed
to said pad at preselected ones of said support points, said
weights opposing said support forces provided by said pulleys at
said support points so that said support forces provided to said
pad at said preselected support points can be varied by varying
said weights.
7. Apparatus in accordance with claim 1 including stabilizer means
for limiting said movement of said pad with respect to said frame
for facilitating movements of said body such as required for
mounting and dismounting said article of furniture.
8. Apparatus in accordance with claim 1 including:
first mounting means for mounting said first set of pulleys to said
frame so that said mounting points can be varied in correspondence
with variations in said support points; and
second mounting means for mounting said second set of low friction
pulleys to said pad so that said spacings between said support
points can be varied whereby said support force distribution can be
adjusted for said body being supported.
9. Apparatus in accordance with claim 1 wherein said support pad
includes a cushion having first and second portions joined by a
relatively flexible portion, said first portion supporting the head
of said body and said second portion supporting the remainder of
said body, said flexible portion accommodating changes in said
contour between said head and said remainder of said body.
10. An article of furniture having a frame with sides and a support
system mounted to said frame for supporting a body resting thereon
including a support pad upon which said body rests having
flexibility in the direction of the longitudinal axis of said body,
said pad having longitudinal edges opposing said sides of said
frame, characterized in that said support system includes:
a first series of low friction pulleys mounted at spaced mounting
points along said sides of said frame;
a second series of low friction pulleys mounted at spaced support
points along said longitudinal edges corresponding to said mounting
points and providing support forces to said pad; and
flexible cords interconnecting said first and second series of
pulleys along respective ones of said edges and said sides and
suspending said pad within said frame so that by a redistribution
of said cords among said first and second series of pulleys said
pad can move relative to said frame to conform to changes in
contour of said body, respective ones of said flexible cords
maintaining substantially constant tension therein so that said
support forces provided to said pad by said second series of
pulleys remain constant regardless of said changes in contour.
11. A support apparatus for supporting a body resting thereon with
a preselected support force distribution ad conforming
automatically to various contours of said body without changing
said preselected support force distribution, comprising, in
combination:
a frame;
a support pad upon which said body rests, said pad having
flexibility in the direction of the longitudinal axis of said
body;
a set of support means connected to said support pad at support
points therealong having spacings therebetween related to said
preselected support force distribution, said set of support means
comprises a plurality of second low friction pulleys mounted to
said support pad;
a plurality of first low friction pulleys mounted to said frame at
spaced points corresponding to said support points; and
a force transmitting means comprising a flexible cord means
interconnecting said pluralities of first and second low friction
pulleys and suspending said support pad from said frame so that by
a redistribution of said cord means among said pluralities of first
and second pulleys said pad can move relative to said frame and
thereby conform to changes in said contour; said cord means having
substantially constant tension therein independent of movements of
said pad so that said plurality of second pulleys provide constant
support forces to said support pad.
12. A support apparatus for supporting a body resting thereon with
a preselected support force distribution and conforming
automatically to various contours of said body without changing
said preselected support force distribution, comprising, in
combination;
a frame;
a support pad upon which said body rests, said pad having
flexibility in the direction of the longitudinal axis of said
body;
a set of support means connected to said support pad at support
points therealong having spacings therebetween related to said
preselected support force distribution, said support means
comprises a plurality of fluid force means mounted to said support
pad; and
a force transmitting means comprising a closed, fluid-filled system
mounted on said frame and interconnecting said plurality of fluid
force means, said system being adapted to permit movement of said
fluid among said fluid force means so that said fluid force means
can deflect to to permit movement of said support pad relative to
said frame to conform thereby to changes in said contour; said
fluid having a substantially constant pressure therein independent
of said pad movements so that said plurality of fluid force means
provides constant support forces to said support pad.
13. A support apparatus for supporting a body resting thereon with
a preselected support force distribution and conforming
automatically to various contours of said body without changing
said preselected support force distribution, comprising, in
combination,
a frame;
a support pad upon which said body rests, said pad having
flexibility in the direction of the longitudinal axis of said
body;
a set of support means connected to said support pad at support
pints therealong having spacings therebetween related to said
preselected support force distribution, said set of support means
comprises a plurality of rigid rods each pivotably mounted on one
end thereof to said support pad and having one of a plurality off
second low friction pulleys on the other end thereof;
a plurality of first low friction pulleys mounted to said frame at
spaced points corresponding to said support points; and
a force transmitting means comprising flexible cord means
interconnecting said pluralities of first and second low friction
pulleys and supporting said support pad from said frame so that by
a redistribution of said cord means among said pluralities of first
and second pulleys said pad can move relative to said frame and
hereby conform to changes in said contour; said cord means having
substantially constant tension therein independent of said
movements of said pad so that said plurality of rods provides a
constant support force to said support pad.
14. A support apparatus for supporting a body resting thereon with
a preselected support force distribution and conforming
automatically to various contours of said body without changing
said preselected support force distribution, comprising, in
combination:
a frame;
a support pad upon which said body rests, said pad having
flexibility in the direction of the longitudinal axis of said
body;
a set of support means connected to said support pad at support
points therealong having spacings therebetween related to said
preselected support force distribution, said set of support means
comprises a plurality of second low friction cord guides mounted to
said support pad;
a plurality of first low friction cord guides mounted to said frame
at spaced points corresponding to said support points; and
a force transmitting means comprising a flexible cord means
interconnecting said pluralities of first and second low friction
cord guides and suspending said support pad from said frame so that
by a redistribution of said cord means among said pluralities of
first and second cord guides said pad can move relative to said
frame and thereby conform to changes in said contour; said cord
means having substantially constant tension therein independent of
movements of said pad so that said plurality of second cord guides
provide constant support forces to said support pad.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a support system for furniture such as
beds and chairs. More particularly, it relates to a support system
for such furniture which readily conforms to the contour of a body
resting on the furniture while supporting the body with a support
force or pressure distribution matched with the body weight
distribution so that increased comfort is provided.
2. Background of the Invention
Most presently used support systems for items of furniture such as
beds and chairs utilize spring and wire arrangements in the body
support pads thereon which provide at best only limited flexibility
in adapting to the specific contour of the supported body. Because
the support force distribution from such systems does not
necessarily match the weight distribution of the supported body,
the body must develop internal bending moments by tensioning of
muscles and hence muscle strain in various parts of the body may
occur. Such support systems are designed for the average person and
thus may not be as comfortable as desired for persons not having
the physical characteristics of the average person. Further, such
support systems may not be comfortable even to the average person
as his body assumes different positions because of lack of
comformability of the support system to specific body contours and
the irregular support force distribution resulting therefrom.
Because of the non-ideal support force or pressure distribution,
i.e., some parts of the body are adequately supported while others
are not so supported, the body itself must behave as a beam by
providing a bridging action from one support point to another
thereby decreasing the comfort of the furniture.
Accordingly, it is an object of this invention to provide a support
system for furniture such as beds and chairs which will readily
adapt to the contour of different bodies supported thereby.
Another object is to provide a support system which will readily
conform to changes in contour of a body being supported by reason
of the body shifting position.
A further object is to provide a support system for furniture by
which bodies thereon are supported by a smooth and predetermined
distribution of support forces which does not vary even when the
body contour changes.
A still further object is to provide a support system for furniture
which provides a support force distribution matched to the weight
distribution of the supported body.
Another object is to provide a support system for furniture which
permits the selection of any one of a plurality of desired support
force distributions.
SUMMARY OF THE INVENTION
The foregoing objects and others are achieved in accordance with
the principles of this invention by a support system which has a
plurality of force means whose spacings, individual support force
magnitudes with respect to each other, or both may be predetermined
to provide a desired support force distribution. For example, the
support force distribution might match the weight distribution of
the supported body. A plurality of the force means are
interconnected by a common force transmitting means and thus some
of the force means may readily change their positions relative to
the other force means by a movement of the force transmitting means
therebetween to accommodate a change in the contour of the body
being supported. The normally desired equilibrium positions, at
which positions the supported body is not required to provide
bridging action, are reached when the support system has adjusted
to the contour of the supported body and the support force
distribution is the same as the weight distribution of the
supported body. At these equilibrium positions there are no
internal bending moments in the supported body as the net load at
each point along the body is zero. At these positions the total of
the individual support forces equals the weight of the supported
body; and moment equilibrium of the support force and weight
distributions is also assured. Other support force distributions,
not necessarily corresponding to the weight distribution, may be
desired in some situations. In such situations, the body must
provide bridging action. However, many support force distributions
may be selected such that moment equilibrium as well as total force
equilibrium is assured.
More specifically, in one embodiment of the invention, the support
system comprises a cushion, support pad, and a suspension system
for the pad including a pulley and cord arrangement. The body to be
supported rests on the cushion which rests on the support pad
mounted in a frame. The pad is stiff in a direction transverse to
the longitudinal axis of the body and has torsional rigidity about
this axis but is relatively flexible in the direction of the
longitudinal axis. Sets of low friction pulleys are mounted along
each side of both the pad and the frame at support points spaced to
provide a support force distribution corresponding to the weight
distribution of the supported body. The pulleys on each side are
interconnected by a continuous force transmitting means, which may
be a simple flexible cord. The pulleys and cord thus provide equal
support forces at each support point. Changes in the contour of the
supported body are accommodated by a shifting or redistribution of
the interconnecting cord between pulleys and a consequent
deformation of the pad relative to the frame until one of the
previously mentioned normally desired equilibrium positions is
reached. The particular spacing of the support points, the support
point forces, and the mounting of the pulleys are such that the
body is supported by a distribution of support forces which does
not vary as the body contour varies.
In a second embodiment of the invention, the support system
comprises a fluid filled support system. Sets of flexible bellows
or fluid cylinders are placed at appropriately spaced points along
the pad. The bellows are interconnected by a fluid transmitting
means such as a simple tube. The tube and bellows or cylinders
contain an appropriate fluid under pressure which is induced by the
supported body. Because the spacing and cross sectional areas of
the bellows may be freely chosen, the distribution of support force
in this embodiment can also be predetermined to a desired
distribution. Changes in the contour of the supported body are
accommodated by a redistribution of fluid among the bellows and a
consequent deflection of the bellows until the equilibrium position
is reached with the force distribution unchanged.
DESCRIPTION OF THE DRAWINGS
My invention will be more fully comprehended from the following
detailed description, which is directed particularly toward an
embodiment utilizing the pulley and cord system in a lounge chair,
and the accompanying drawing in which:
FIG. 1 is a schematic representation in perspective of the lounge
chair utilizing the support system of this invention.
FIG. 2 is an enlarged schematic representation along direction 2--2
of FIG. 1 showing the suspension system of the lounge chair in
greater detail including auxiliary supports which function when the
displacement of the support pad exceeds a predetermined amount.
FIG. 3 is an enlarged schematic representation along direction 3--3
of FIG. 1 showing how the suspension system for the back rest
portion advantageously is mounted to the chair frame.
FIG. 4 is a schematic representation of a bracket assembly to keep
the pad on the back rest portion of the chair from sagging.
FIG. 5 illustrates a configuration for a cushion which can be used
advantageously in the support system.
FIG. 6 is a schematic of a latch and spring assembly for locking
the back rest portion in a desired position and for aiding in
moving the back rest portion from reclining to sitting
position.
FIG. 7 is a schematic representation in perspective of the bottom
of the chair of FIG. 1 showing in particular a stabilizer
assembly.
FIG. 8 A, B, C, is a schematic representation of the operation of
the stabilizer assembly of FIG. 7.
FIG. 9 is a schematic representation of another embodiment of the
support system of my invention utilizing pulleys and cords and
rigid rod links.
FIG. 10 is a schematic representation of still another embodiment
of the invention utilizing fluid support means.
DETAILED DESCRIPTION
FIG. 1 is a schematic representation in perspective, partly broken
away, of a lounge chair 101 which utilizes a pulley and cord
embodiment of my invention in its support system. The chair 101
comprises a seat and leg portion 2 and a back rest portion 4
pivotably mounted at 6 to the rear edge of the seat and leg portion
2. Back rest portion 4 is shown in a partially reclined position
but may be placed in any position from substantially upright to
fully reclined.
A body resting on the chair 101 is supported by a pad 8 over which
a cushion 10 made of some material such as foam rubber may be
placed. For reasons which will subsequently become more apparent,
the pad 8 should be very flexible along the longitudinal direction
of the body being supported and should normally be relatively stiff
in a direction transverse to the longitudinal axis of the supported
body. The pad 8 should also have substantial torsional rigidity
about the longitudinal axis. FIG. 2 illustrates more clearly how
these characteristics are obtained. The pad 8 comprises two sheets
12 of flexible material such as polyethylene between which
relatively stiff slats 14 such as wooden strips are sandwiched. The
sandwich construction gives torsional rigidity and the orientation
of slats 14 transverse to the longitudinal axis provides transverse
stiffness but the pad 8 remains quite flexible in the longitudinal
direction, i.e., along the longitudinal direction of the body being
supported.
Under some circumstances, it might be desirable for the pad 8 to
have some flexibility transverse to the supported body. For
example, if the chair 101 is to be left in the rigidized or
stabilized position, to be subsequently described, for extended
periods, some transverse flexibility would be desirable. Further,
if significant changes in the transverse contour of the supported
body are anticipated, some transverse flexibility is desirable.
Such transverse flexibility can be attained by adapting slats 14 to
be flexible in their longitudinal direction.
The support pad 8 is suspended from the chair frame 16 in a manner
now to be described. As shown in FIGS. 1 and 2 a plurality of low
friction pulleys 20 are arranged in pairs and mounted at
appropriately spaced points along the inside surfaces of each of
the side portions 18 of the chair frame 16. A low friction pulley
22 is also mounted at each end of a number of correspondingly
spaced slats 14. A continuous, flexible cord 24 interconnects the
pulleys 20 and 22. Cord 24 may be any material such as nylon or
wire which has sufficient strength, flexibility and wear
properties. The use of a stretchable material such as rubber in
cord 24 may be advantageous in certain situations to improve the
functioning of the support system. Such a compliant material might
be especially desirable in the rigidized or stabilized position and
in conjunction with the auxiliary supports, both previously
mentioned and to be subsequently described. Stretchability can also
be introduced by inserting an element such as a spring in series
with cord 24.
The interconnecting cord 24 is cut to a predetermined length and
after the pulleys 20 and 22 have been interconnected therewith, the
ends of the cord 24 are anchored at points 26 and 28. In a lounge
chair as herein described wherein the back rest portion 4 can
assume various positions between upright and fully reclined, it is
desirable that the support system for the back rest portion 4 be
independent of the support system for the seat and leg portion 2.
Thus in FIG. 1 and 3 a separate interconnecting cord 30 for the
back portion 4 is shown anchored at points 32 and 34. In an
application of the invention to a bed mattress support system
wherein all portions of the mattress remain substantially
horizontal and planar at all times, cords 24 and 30 could be joined
and anchors 28 and 32 could be eliminated.
It is apparent from FIGS. 1 and 2 that the pairs of pulleys 20 are
variably spaced along the sides 18 of the frame. The spacing
ideally is inversely proportional to the incremental density of the
supported body. Thus the pulleys 20 in the leg and feed supporting
area are spaced further apart than are the pulleys 20 in the hips
supporting area where a greater concentration of weight is normally
expected. For example, if the density of the body is such that legs
and hips create loads of 1 pound and 2 pounds per unit length along
the pad, respectively, then the spacings of the pulleys would be 2
units and 1 unit, respectively, in the leg and hip support areas,
respectively. Slats 14 in pad 8 are spaced to correspond to the
spacing of the pulleys 20. Thus, in some sections of pad 8, such as
the feet supporting area where normally there is very little
weight, the slats 14 are widely spaced. The pad 8 may have a
tendency to sag in these sections because of its flexibility in the
longitudinal direction. Sagging can be prevented by inserting
auxiliary slats 36, to which no pulleys are attached, in these wide
spaces and bridging across the spaces as shown in FIG. 1 with
stiffeners 38 which may be thin metal straps. One of the more
important contour changes which can be accommodated is the flexing
of the legs at the knees. To help accommodate this particular
contour change it may be advantageous to locate one support point
at the knees.
Since the cords 24 and 30 are continuous within their respective
support areas, and the pulleys 20 and 22 have low friction, it
follows that the tension at each point in a particular one of the
cords is essentially the same as the tension at every other point
within that cord. Also because of the close spacing of the pairs of
pulleys 20 at a particular support point, the support force
distribution is virtually unaffected by vertical translations of
the pulleys 22 relative to the pulleys 20 as the vertical cord
segments remain vertical at all times. Thus following any change in
the contour of the supported body, the support system will quickly
adjust to a new equilibrium position without changing the support
force distribution. This is accomplished by vertical movements of
pulleys 22 with respect to pulleys 20 and a redistribution of the
interconnecting cords 24 and 30 between pulleys. For example, if
the legs of the supported body are flexed, the tension in the
support cord segments in the foot region would momentarily be
greater than the tensions in the cord segments in the hips support
section. Thus the foot support section would displace by vertical
translation of pulleys 22 with respect to pulleys 20 thereby
drawing additional amounts of cord from the hips support section
until a new equilibrium position was reached. The tension in the
cord after equilibrium has been achieved will be the same as before
the change in body contour and the support force distribution
likewise is undisturbed even though the contour of the body has
changed.
Because only a finite number of pulleys may be used, there is a
need for some smoothing of the discrete forces provided at the
support points. Cushion 10 provides this smoothing through the use
of a compliant material therein.
As the number of pulleys 20 and 22 is increased, thus increasing
the number of vertical cord segments 23, the tension required in
the interconnecting cords 24 and 30 to support a particular body
decreases. The relative spacings between pulleys are maintained so
that the support force distribution continues to match the body
weight distribution. Thus the function of the cushion 10 becomes
less important for smoothing the pressure distribution along the
body. The cushion remains important for smoothing the support
pressure in the direction transverse to the body however.
In some sections of the suspension system, the addition of large
concentrations of weight would upset the ideal condition of having
the support force distribution match the body weight distribution.
For example, when the back rest portion 4 is elevated to a near
upright position, there would be a large weight concentration in
the hips support section. This would tend to cause this section to
displace excessively and the body would then act as a bridge or
beam in the hip region since the support in this region would be
insufficient. In such a case auxiliary supports 40, as shown in
FIG. 2 enclosed in the dotted line, can be utilized to provide
additional support for the hips region. These auxiliary supports 40
comprise rigid bars 42 slidably mounted in a bracket 44 on frame
side portion 18. The bottom end of bar 42 is fastened to an
auxiliary support slat 46 and on the top end is mounted a low
friction pulley 48, similar to pulleys 22, which normally does not
contact cord 24. As the hips support section is displaced downward
because of the increased weight concentration, the bar 42 is pulled
downward. When the displacement exceeds a predetermined amount, the
pulley 48 engages cord 24 and establishes a new support point which
supplies a support force for the increased weight. This prevents
further displacement of the hips support section. The hips support
area of the chair will normally be the only section requiring
auxiliary supports and such supports will only come into operation
when the chair is raised to an upright position thereby
concentrating the supported weight in the hips support area. If
cord 24 is stretchable, the increased weight supported in the seat
and leg portion 2 when the back rest portion 4 is elevated will
lower the entire body. Therefore the auxiliary supports 40 can be
brought into play without the hips having to be substantially lower
than the legs.
In applications of the support system to a lounge chair 101 wherein
the position of the back rest portion 4 may be varied, it is
desirable to have the support system for the back rest portion
mounted on a movable bar or rail assembly 50 as shown more clearly
in FIG. 3. This applies whether the support system for the back
rest portion 4 is completely independent of the support system for
the seat and leg portion 2 or whether the two sections form a
continuous support system.
The horizontal mid-plane of support pad 8, i.e., the mid-plane with
respect to the thickness of pad 8, does not pass through the pivot
axis 6. Thus when the back frame portion 52 of chair 101 is raised
from a horizontal position, the back support portion 53 of pad 8
will tend to be pulled toward pivot 6. This will tend to displace
pulleys 22 mounted to the back support portion 53 such that the
cord segments 58 joining pulleys 22 and 20 will not remain
perpendicular to the back frame 52. The cord segments, when not
perpendicular, introduce stretching forces into back support
portion 53 making it less comfortable and flexible. This problem
can be alleviated by mounting the pulleys 20 for the back rest
portion 4 on a rail 54 which is rollably mounted to the back frame
52 on rollers 56 as shown in FIG. 3. As the back frame portion 52
is raised the rail 54 moves along frame portion 52 carrying the
pulleys 20 mounted thereon. Thus these pulleys 20 move as pulleys
22 move. This motion of the support rail 54 insures that the
support cord segments 58 for the back rest portion 4 remain
substantially perpendicular to support pad 8 and the desired
support force distribution is maintained.
In some situations it may be desirable to have little or no support
force on a particular portion of the supported body. For example,
if a particular portion of the body were injured, it might be
desirable to eliminate all forces on the injured portion. This
result can be achieved by at least two methods. First, the support
cord 24 or 30 may be removed from the pulley 22 on the slat 14
immediately under this portion of the body thereby removing the
support force at this point. The supported body must then bridge
across this gap between the next adjacent support points thru its
internal body structure. Secondly, counterweights 60, shown in
FIGS. 2 and 3, can be used to counterbalance the support forces
ordinarily applied to the supported body at the support points. The
counterweights 60 balance the tension in the cords 24 and 30
thereby resulting in a low net support force being applied to the
supported body at the point of interest. The counterweights 60 are
attached to the slat 14, preferably along the axis of symmetry of
the pad 8, at the points where it is desired to reduce the support
force.
Counterweights 60 may also be added in certain portions of the
chair 101 such as the foot support area and head support area so
that the net support force distribution can be made to match the
body weight distribution with a relatively lower number of support
points. If a low number of support points is used for the entire
pad 8, the tensions in cords 24 and 30 will be greater. This will
tend to cause discomfort in the foot support and head support areas
because of the relatively high support forces. However,
counterweights 60 used in these areas alleviate any discomfort by
reducing the net support forces applied to the feet and head.
When counterweights 60 are used in the head support area of the
chair, the counterweights 60 may tend to cause the cushion 10 and
back support section 53 of support pad 8 to sag when the chair back
is in the upright position. This sagging, primarily from the weight
of pad 8 and counterweights 60, is in addition to the movement
which causes the stretching forces previously discussed. This
sagging can be prevented by a small bracket arrangement shown in
FIG. 4. A rod or bar 62 has one end fixedly attached to rail 54
substantially perpendicular thereto and the other end is slidably
engaged in a bracket 64 mounted on pad 8 on one edge of a widened
slat 15. This arrangement constrains the movement of the support
pad 8 to be substantially perpendicular to the back frame portion
52 thereby eliminating the problem of sagging. This bracket
arrangement may be desirable even when no counterweights are used
in order to prevent any sagging from the weight of the pad and
support system itself.
Because of the acute profile change encountered between the head
and shoulders of a body, it is desirable to design the cushion 10
to help reduce the variations in deflections of the support pad 8
required in this portion of a chair or mattress as the body turns.
As shown in FIG. 5, this can be accomplished in part by making the
head rest portion 66 of cushion 10 somewhat thicker than the body
rest portion 67 of the cushion 10 and connecting the two portions
by a relatively thin short flexible section 65. The nominal
position of the mid-plane 69 of the head rest portion 66 is higher
than the mid-plane 71 of the body rest portion 67 of cushion 10 to
most satisfactorily accommodate the various possible contours of
the body. The thicker head portion 66 allows the head to be
supported, regardless of the position of the body, with the
appropriate force corresponding to the weight of the head without
the neck being strained or the head being out of its normal
position along the longitudinal axis of the body. In some
situations it may be advantageous to have materials of different
compliance in the head rest 66 and body rest portion 67 of cushion
10. It also may be advantageous to fasten cushion 10 to pad 8 so
that they act as a single unit.
The lounge chair 101 has a latch and spring assembly 68, shown more
fully in FIG. 6, for locking the back rest portion 4 in any
position between the vertical and horizontal and for automatically
raising the back rest portion 4 toward the vertical position when
the body is raised from the back rest portion 4. The assembly 68
comprises a handle 70 having affixed thereto a metal block 72
having good wear resistant properties. Block 72 has a hole 74
therethrough. Block 72 could also be formed as a sandwich
construction of independent thin slices of material having aligned
holes therethrough. A rod 76 having a size only slightly smaller
than the size of hole 74 is slidably mounted in hole 74 and has one
end thereof engaged in a bracket 78 on back frame portion 52 such
that rod 76 may apply a force to frame 52 causing it to tend to
rotate about pivot 6. The other end of rod 76 engages one end of a
spring 80 having the other end mounted to side frame 18 toward the
front thereof. Handle 70 and block 72 float freely on rod 76.
Spring 80 is biased so that it exerts a continuous and substantial
force on rod 76 tending to cause back frame 52 to rotate to the
fully upright position. Handle 70 and block 72 are contacted by a
spring 82 which is mounted to a stop 83 on the side of handle 70
adjacent spring 80. Another stop 84 is rigidly mounted to side
frame 18 on the opposite side of handle 70. Stop 84 and spring 82
tend to rotate handle 70 and block 72 forwardly in such a manner as
to cause the edges of hole 74 nearest spring 80 to bite into rod 76
when rod 76 tries to move rearwardly such that rod 76 is locked in
any desired position and prevented from further rearward motion.
Rod 76 can be moved rearwardly, thus causing back rest portion 4 to
recline, by manually rotating handle 70 rearwardly to counteract
spring 82 and simultaneously applying a slight force to back rest
portion 4. The rear edges of hole 74 do not bite into rod 76. Thus
when all force is removed from back rest portion 4, spring 80 can
pull rod 76 forwardly, since it is not locked against forward
motion, thereby raising back portion 4. Stop 83 prevents handle 70
from being rotated too far rearwardly which would cause rod 76 to
bind.
Although separate spring assemblies 68 are shown on each side of
the chair, a single assembly could be utilized. Further, such
modifications as utilizing only one handle 70 to control the spring
assemblies 68 on both sides could be made. Other latch and spring
mechanisms which will be apparent to those skilled in the art can
be utilized.
Because of the "floating action" achieved by he support system
supplying forces that are independent of body contour changes, it
is desirable to temporarily stabilize or rigidize the support
system when getting on or off a chair or bed mattress supported by
the suspension system of this invention. FIG. 7 discloses one
method of so stabilizing the support system.
Two stabilizer boards or panels 86 are rotatably mounted, about
axes parallel to the longitudinal axis of the chair or mattress, on
the underside of frame 16. Transversely interposed between, and
slightly beneath stabilizer panels 86, and rotatably mounted about
an axis perpendicular to the axis of rotation of panels 86, is an
actuating panel 88. Actuating board or panel 88 is fastened along
one edge 90 to a rod 96, rotatably mounted in frame 16, which is
connected on one end to an actuating handle 98. Along the opposite
edge 94, the ends 92 of panel 88 are rounded and have increased
thickness. The edges of panels 86 opposite their axes of rotation
are also rounded. When the chair or mattress is being used, handle
98 is placed in a position such that panel 88 lies flat underneath
the frame 16, i.e., handle 98 is rotated to its forward position,
and consequently panels 86 also lie flat and do not contact support
pad 8. Thus the support system can operate as previously described
to accommodate changes in the supported body.
As illustrated in FIG. 8 A, B, C, when handle 98 is rotated
rearwardly, actuating panel 88 is caused to rotate also. The
rounded ends 92 of panel 88 contact stabilizer panels 86 forcing
them to rotate from their previous flat position to an upstanding
position and consequently contact support pad 8 along a substantial
length of the underside edges thereof. Because of the transverse
stiffness of support pad 8, it is subsequently prevented from
further movement but is in essence "bottomed" on stabilizer panels
86. Thus movement onto or off the chair or mattress is facilitated.
A layer of low friction, wear-resistant material may advantageously
be placed on the rounded ends 92 of board 88 and on those portions
of panels 86 which are contacted by ends 92. Such a layer 104 is
shown in FIGS. 7 and 8.
The suspension system also can be stabilized to facilitate movement
onto or off a chair or mattress by locking or holding support cords
24 and 30 in a particular position.
While the invention has been described with particular reference to
a reclining lounge chair utilizing pulley and cord apparatus, it
should be clearly understood that various modifications to the
disclosed embodiment can be made without departing from the spirit
and scope of the invention.
For example, as illustrated in FIG. 9, the invention is clearly
applicable to a chair or mattress design wherein the support pad 8
and cushion 10 are not suspended between the sides of a frame but
are supported above the frame 16. A plurality of pairs of pulleys
20 are mounted on the frame 16 and interconnected by a cord 24. A
plurality of rigid links 106 are slidably mounted on frame 16 in
brackets 108. One end of each link 106 is pivotably connected to a
slat 14 in pad 8 at pivot 110 and the other end of the link
contains a pulley 112 which engages cord 24. In this embodiment it
would be possible to use a single row of pulleys 20 and supporting
links 106 down the center of the pad 8.
Non-rotating wire guides having a moderately low friction surface
can be substituted for the pulleys with some departure from ideal
behavior. Some friction in the pulleys or cord guides can be
tolerated without seriously degrading the performance of the
support system as previously described. Two effects are provided by
friction which might be beneficial under certain circumstances.
These effects are the provision of more traction for the body for
shifting positions and the allowance of slight variations from the
preselected support force distribution by small movements of the
body. The pivots 110 shown in FIG. 9 and 10 also could be replaced
by connections having only limited rotational capability without
serious departure from ideal behavior. Various pulleys such as the
pairs of pulleys 20 might be combined on a single shaft.
Pulleys 20 can be mounted in such a manner as to permit adjustment
in mounting position on frame 16. For example, a continuous row of
mounting apparatus having a plurality of closely spaced mounting
ports for pulleys 20 can be placed along the sides of frame 16.
Alternatively, pulleys 20 can be mounted in pairs on brackets that
are slidably connected to a rail mounted on frame 16. Pulleys 20
can then be moved in position along frame 16. Corresponding
adjustments in position of slats 14 in support pad 8 might also be
provided by providing a plurality of closely spaced compartments
for slats 14 in pad 8 such that pulleys 22 may correspondingly be
moved in position by moving slats 14 from one compartment to
another. This adjustable mounting will permit tailoring of the
support system for particular persons utilizing the furniture. More
convenient methods of adjusting the mounting positions of pulleys
20 and 22 will be apparent to those skilled in the art.
As previously mentioned a fluid or hydraulic system can be utilized
in place of the pulley and cord apparatus. One such system is
illustrated in FIG. 10. Here a plurality of hydraulic cylinders 114
are interconnected by a continuous tube 116 containing a nearly
incompressible fluid. The cylinders 114 can all have the same cross
sectional area so that each exerts the same force or the support
forces can be varied by varying the cross-sectional area. In the
former case the spacings between cylinders are varied while in the
latter case the forces are varied to achieve the desired support
force distribution. Each cylinder 114 contains a piston 118 having
a shaft 120, one end of which is rotatably connected to a slat 14
in support pad 8. Each cylinder 114 contains the same pressure, and
thus the fluid will redistribute and the pistons will displace to
accommodate any change in the contour of the supported body without
changes in the support force distribution. The cylinder and piston
arrangement can readily be replaced by a series of flexible
bellows.
In some situations it might be desirable to have only part of an
article of furniture supported by a support system as herein
described. For example, airplane and bus seats might advantageously
utilize the support system for only the back rest portion thereof
while retaining the presently used designs for the hips support
portion. This would provide a seat which would conform to the upper
part of the body and greatly facilitate sleeping therein but which
would not be too bulky to prevent its usage. Apparatus associated
with the stabilizer would not required in such a seat. Such a seat
could be designed readily because of the previously described
independent support systems for the back rest portion and seat and
legs portion of the described lounge chair.
Although the cushion 10 and support pad 8 were described as
distinct items in the illustrative embodiment, these items could be
made as a single unit.
Various other modifications can be made by those skilled in the art
and without departing from the spirit and scope of this
invention.
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