U.S. patent application number 16/039582 was filed with the patent office on 2018-12-06 for wheelchair with four wheel independent suspension and modular seating.
This patent application is currently assigned to Dream Roller Mobility, LLC. The applicant listed for this patent is Dream Roller Mobility, LLC. Invention is credited to Price Daniels Cobb, Thomas Allan Mitchum, Mark Kleber Nearburg, Royal Leo Vereen, III.
Application Number | 20180344548 16/039582 |
Document ID | / |
Family ID | 64459145 |
Filed Date | 2018-12-06 |
United States Patent
Application |
20180344548 |
Kind Code |
A1 |
Vereen, III; Royal Leo ; et
al. |
December 6, 2018 |
WHEELCHAIR WITH FOUR WHEEL INDEPENDENT SUSPENSION AND MODULAR
SEATING
Abstract
This invention provides a wheelchair with four-wheel independent
suspension and modular seating, allowing for customized seat
selection and a variable ride. It includes a chair assembly, a
chassis assembly and a suspension assembly. The chair assembly
includes a seat; a seat mount; a seat angle adjuster; and a pillar.
The chassis assembly includes a chassis; and a handle assembly. The
suspension assembly incudes a forward suspension assembly and a
rear suspension assembly. In another embodiment, the wheelchair
includes a chair assembly with handles, a main cross beam and a
suspension spring assembly.
Inventors: |
Vereen, III; Royal Leo;
(Bulverde, TX) ; Nearburg; Mark Kleber; (Lakeway,
TX) ; Cobb; Price Daniels; (Austin, TX) ;
Mitchum; Thomas Allan; (Lakeway, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dream Roller Mobility, LLC |
Lakeview |
TX |
US |
|
|
Assignee: |
Dream Roller Mobility, LLC
|
Family ID: |
64459145 |
Appl. No.: |
16/039582 |
Filed: |
July 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15244647 |
Aug 23, 2016 |
10052247 |
|
|
16039582 |
|
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|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60G 2300/24 20130101;
B60G 2200/13 20130101; A61G 5/107 20130101; A61G 7/1025 20130101;
A61G 5/1091 20161101; A61G 7/103 20130101; A61G 5/1075 20130101;
A61G 5/1078 20161101; A61G 5/128 20161101; B60G 5/06 20130101 |
International
Class: |
A61G 5/10 20060101
A61G005/10; B60G 5/06 20060101 B60G005/06 |
Claims
1. (canceled)
2. A suspension assembly comprising: a front suspension arm
attached to a support portion at a suspension arm mounting point,
and attached to a front wheel hub; a front shock absorber attached
to the front suspension arm at a front shock-arm mounting point,
and attached to the support portion at a front shock-support
mounting point, wherein the suspension arm mounting point is
distinct from the front shock-support mounting point; a rear
suspension arm attached to the support portion at the suspension
arm mounting point, and attached to a rear wheel hub; a rear shock
absorber attached to the rear suspension arm at a rear shock-arm
mounting point and attached to the support portion at a rear
shock-support mounting point, and wherein the rear shock-arm
mounting point is distinct from the suspension arm mounting
point.
3. The system of claim 2, wherein the rear shock-support mounting
point is distinct from the front shock-support mounting point.
Description
RELATED APPLICATIONS
[0001] This application is a Continuation of application Ser. No.
15/244,647, filed 23 Aug. 2016 (the "First Parent
Application").
[0002] The First Parent Application is a Non-Provisional Patent
Application claiming priority to U.S. Provisional Patent
Application Ser. No. 62/208,875, filed 24 Aug. 2015 (the "Second
Parent Application").
[0003] The First Parent Application is also a Non-Provisional
Patent Application claiming priority to U.S. Provisional Patent
Application Ser. No. 62/329,176, filed 28 Apr. 2016 (the "Third
Parent Application").
[0004] This application claims benefit to the First, Second and
Third Parent Applications, collectively the "Related References",
and hereby claims benefit of the filing dates thereof pursuant to
37 CFR .sctn. 1.78(a)(4).
[0005] The subject matter of the Related References, each in its
entirety, is expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0006] This invention relates to wheelchairs, and more particularly
to a wheelchair having an independent suspension.
BACKGROUND OF THE INVENTION
[0007] Wheelchairs are an integral component in the lives of people
who are temporarily or permanently disabled. In some cases, a
wheelchair bound occupant is fully dependent on a caregiver.
Commercially available wheelchairs provide a structure to hold an
individual occupant for a short period of time, but are not
comfortable for a significant amount of time on a daily basis. A
typical commercially available wheelchair is a folding unit with a
tubular steel frame and does not have any suspension system. The
wheelchair is constructed with the seat area as an integral part of
the chassis with attached wheels, footplates, handles and a back
rest. The chassis is completely integrated into the chair, without
consideration of dissipation of energy. The wheelchair does not
have any shock absorbing or energy dispersing mechanisms,
translating all of the energy from the frame to the occupant. A
caregiver pushes the chair to furnish motive force, or it is
self-propelled via appropriate motors and controls. With the chair
being a stressed member of the chassis, every bump and jolt
experienced by the chair moving across a surface is immediately and
directly translated to the occupant as anxiety and discomfort.
Furthermore, the placement of footrest and the size of the rear
wheels can inhibit access to the occupant by the caregiver. This
can make re-positioning the occupant more difficult.
[0008] A wheelchair is commonly used to transport an individual
within a structure, to and from transportation and in the out of
doors. Certain transportation vehicles can be adapted so as to
contain the individual within the wheelchair inside the vehicle, so
as to minimize movement from the chair to the vehicle and
vice-versa. Movement within a building is generally across
relatively level floors, with transitions between carpeted and bare
floors, across thresholds and sometimes up one or more stairs.
Movement outside buildings can be on a levelled surface or an
uneven surface. Over time there has been an increase in development
of trails in parks, thereby increasing access to previously
inaccessible portions.
[0009] Movement for an individual can be anxiety-causing.
Wheelchairs tend to be top-heavy and stability during any movement
is a factor. Most of the energy absorbed by the frame is directly
transferred through the seat to the individual. Some individuals
have little to no control over their body orientation, while others
may possess a strong muscular core in their torso, but have little
to no control over their extremities. Others may have a strong core
and limited use of extremities, such that they can re-position
themselves within the chair. When an individual cannot adequately
re-position themselves, they must rely on caregivers to do that for
them. The inability to re-position themselves can cause a sense of
panic when a wheelchair is violently jolted and the individual
slides to and fro in their seat. Those who are able take it for
granted to reposition their own body in a chair when a muscle is
sore, a leg falls asleep or the chair unexpectedly threatens to
spill the sitter to the floor. But this is not so for everyone, and
when the ability to re-position is not present, there can be a
lurking dread of falling or injury whenever the wheelchair is
jostled. This fear can become a limiting factor in the enjoyment of
life. An individual in a chair may become reluctant to travel into
a park because the terrain of the trail is varied or rough. This
could lead to an individual missing out on many pleasures. For
example, an individual who is a car fanatic might be reluctant to
travel to a place where off-road vehicles are competing in a hill
climb because the trail is stony.
[0010] The comfort of a wheel chair relies in part on the seat,
both for how well it holds the user and how well shock is dispersed
before reaching the seat. However, the seat is typically an
integral component that offers few if any options to the user with
regard to comfort, ergonomics or general fit. Wheelchair
accessories commercially available on the market include various
supplemental seating cushions, pads and inserts. In many instances,
the wheelchair bound individual is dependent for all daily activity
on his or her wheelchair and the lack of variety in seating options
is highly disadvantageous. Additionally, the fame and suspension
system in most wheelchairs is relatively limited, and does not take
advantages of advanced construction techniques and/or materials
that are now commercially available and used in a wide range of
contemporary manufactured products. It would be desirable to
provide a system with interchangeable seats that can be adapted to
the individual user that is mounted on a chassis that can displace
shocks and energy and thereby create a smooth, enjoyable ride for
the individual.
SUMMARY OF THE INVENTION
[0011] The present invention overcomes the disadvantages of the
prior art by providing a wheelchair with an independent suspension
and a modular seating arrangement that allows for ready
customization of the seating element and/or suspension via a novel
seat base structure. In an embodiment, the wheelchair includes a
chair assembly; a chassis assembly; and a suspension assembly. The
chair assembly includes a seat; a seat mount; a seat angle
adjuster; and a pillar. The chassis assembly includes a chassis;
and a handle assembly. The suspension assembly incudes a forward
suspension assembly; and a rear suspension assembly. In another
embodiment, the wheelchair includes a chair assembly; a main
structural cross beam; and a suspension spring assembly. In further
embodiments, the suspension system can define a coil spring system,
a gas traction shock system and a torsion spring system. In an
embodiment, the wheelchair is comprised of a removable seat
assembly; a mounting pillar; a chassis; a suspension assembly; and
a plurality of wheels. The suspension assembly is an independent
suspension system that includes a) two front suspension arms that
are connected to an axle at one end and a front wheel at the other,
b) two rear suspension arms that are connected to the axle at one
end and a rear wheel at the other. Each of the suspension arms can
be provided with a shock absorber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention description below refers to the accompanying
drawings, of which:
[0013] FIG. 1 is a side view of a wheelchair, according to a first
embodiment;
[0014] FIG. 2 is a frontal perspective view of a wheelchair,
according to a second embodiment;
[0015] FIG. 3 is a schematic side view, according to the second
embodiment;
[0016] FIG. 4 is a top view of a wheelchair, according to the
second embodiment;
[0017] FIG. 5 is a bottom view of a wheelchair, according to the
second embodiment;
[0018] FIG. 6 is an exploded perspective view of a wheelchair,
according to a third embodiment;
[0019] FIG. 7 is a side view of the wheelchair, according to the
third embodiment;
[0020] FIG. 8 is a frontal perspective view of the wheelchair,
according to a third embodiment;
[0021] FIG. 9 is a perspective view of the wheelchair, according to
the third embodiment;
[0022] FIG. 10 is a view of the shock tower and shock assemblies,
according to the third embodiment;
[0023] FIG. 11 is a view of a portion of the chassis assembly,
according to the third embodiment;
[0024] FIG. 12 is a view of the suspension assembly, according to
the third embodiment;
[0025] FIG. 13 is a side view of the chassis assembly, according to
the third embodiment;
[0026] FIG. 14 is a view of the chassis assembly and suspension
assembly, according to the third embodiment;
[0027] FIG. 15 is a view of the chassis assembly and suspension
assembly, according to the third embodiment;
[0028] FIG. 16 is a view of a caregiver foot lever attached to the
T-post, according to the third embodiment;
[0029] FIG. 17 is a perspective view of a wheelchair with a gas
traction shock, according to a fourth embodiment;
[0030] FIG. 18 is a view of a chassis assembly for the wheelchair
with a gas traction shock, according to the fourth embodiment;
[0031] FIG. 19 is a side view of the wheelchair with a gas traction
shock, according to the fourth embodiment;
[0032] FIG. 19A is a side view of a wheelchair with an alternate
position for the gas traction shock, according to the fifth
embodiment;
[0033] FIG. 20 is a perspective view of a wheelchair with a torsion
spring shock system, according to a sixth embodiment;
[0034] FIG. 21 is a detail view of a torsion spring, according to
the sixth embodiment;
[0035] FIG. 22 is a perspective view of a chassis for a wheelchair,
according to a seventh embodiment;
[0036] FIG. 23 is an exploded view of a wheelchair, according to
the seventh embodiment;
[0037] FIG. 24 is a side view of a chassis for a wheelchair,
according to the seventh embodiment;
[0038] FIG. 25 is a side view of a chassis with wheels for a
wheelchair, according to the seventh embodiment;
[0039] FIG. 26 is a top view of a chassis for a wheelchair,
according to the seventh embodiment;
[0040] FIG. 27 is a front view of a chassis for a wheelchair,
according to the seventh embodiment;
[0041] FIG. 28 is a cross section view of the suspension arms,
taken along line 28-28 of FIG. 26, according to the seventh
embodiment;
[0042] FIG. 29 is a side view of a wheelchair, according to the
seventh embodiment;
[0043] FIG. 30 is a perspective view of a wheelchair with a single
footrest, according to the seventh embodiment;
[0044] FIG. 31 is a perspective view of a wheelchair with two
footrests, according to the seventh embodiment;
[0045] FIG. 32 is a side view of a wheelchair, according to the
seventh embodiment;
[0046] FIG. 33 is a side view of a tilting mechanism for a
wheelchair, according to an eighth embodiment;
[0047] FIG. 34 is a view of a mesh seat for a wheelchair, according
to a ninth embodiment;
[0048] FIG. 35 is a view of a race car style seat for a wheelchair,
according to a tenth embodiment;
[0049] FIG. 36 is a view of a seat for a wheelchair with foldable
transfer boards, according to an eleventh embodiment; and
[0050] FIG. 37 is a view of a caregiver handle for a wheelchair,
according to a twelfth embodiment.
DETAILED DESCRIPTION
[0051] I. Leaf Spring Suspension
[0052] An exemplary wheelchair 100 is depicted in FIG. 1. In an
illustrative embodiment, wheelchair 100 is a mobility system that
is comprised of three assemblies, a chair assembly 110, a chassis
assembly 140 and a suspension assembly 158. The wheelchair 100 as
shown is dimensioned according to the proportions of an average
sized individual weighing between 50 and 250 pounds, and in other
embodiments, it is contemplated that the size of the wheelchair
system can be proportionately larger or smaller, depending on the
size of the user (for example, smaller in the case of a child and
larger for a big or tall adult). In an embodiment, a wheelchair 100
has an overall length OL of approximately 32 inches (81 cm) and an
overall height OH of approximately 42 inches (107 cm). The chair
assembly 110 is comprised of a seat 112, a seat mount 114, a seat
angle adjuster 116 and a hydraulic cylinder 118 that is a pillar
that connects the seat 112 at its upper end to the frame 120 at its
lower end. The seat 112 is a molded contoured structure that can be
provided with an upholstered cover for comfort and additional
support. The seat can also be computer modeled to adapt to the
particular physical contours of the occupant. In a further
embodiment, it is contemplated that the seat can be provided with
internal heating coils for warmth. The composition of the seat 112
is a rigid polymer and can be formed of natural or synthetic
materials. The seat can be readily removed from the pillar and is
interchangeable with other chairs that have been fitted with an
adapter for a mounting mechanism. Given that the wheelchair can
have a use life of more than twenty years, replacement of the seat
for use or to change activities is relatively easy provided that
the replacement has the adapter in place.
[0053] Seat angle adjuster 116 allows for adjustment of the seat
relative to a vertical axis VA drawn upward from the hydraulic
cylinder 118. A seat axis SA is defined as a line drawn from the
forward leading edge 122 of the seat 112 to the opposite rear end
124 of the seat. The seat adjuster 116 is a locking device that is
manually operated by a lever that can be actuated to allow for a
forward or rearward motion of the seat 112. The seat angle adjuster
is mounted on top of the hydraulic cylinder 118 and when unlocked
allows a forward and rearward motion of up to 15.degree. (fifteen
degrees) in an angular range .theta. of the seat angle SA relative
to the vertical angle VA. This range of motion can be selected by
the user or the user's caregiver. The seat is rotatable in a range
of motion 126 of 90.degree. (ninety degrees) to the right or left
of an axis WA drawn from the front end 128 of the wheelchair 100 to
the rear end 130. This corresponds to a swivel action in a range of
motion of 180.degree. (one hundred and eighty degrees) from left to
right, and back. It is contemplated that the orientation of the
chair 110 relative to axis WA can be maintained by locking the
swivel action with a locking device, for example, a locking lever
or detent button.
[0054] In various embodiments, the chair assembly 110 can be
elevated or lowered by operation of a hydraulic cylinder 118. The
hydraulic cylinder 118 can be actuated by a foot pump 132 that
causes the cylinder 118 to raise and lower the seat height SH. The
cylinder has a range of motion of 5 inches (13 cm). The foot pump
132 enables the caregiver to select the correct height for lifting
and moving the user for ease of ingress and egress and caregiver
safety. The caregiver can match the height of the seat to other
objects, for example, tables, chairs and beds. The elevation and
lowering of the chair assembly 110 provides comfort for both the
user and caregiver.
[0055] The chassis assembly 140 can be connected to the forward
spring arm 142 that connects a chassis 144 with a pair of forward
wheels 128 and provides shock absorption. The chassis assembly 140
includes the chassis 144 and a handle assembly 150. A rear spring
arm 170 connects the chassis 140 with the rear wheels 130. A base
148 can be mounted on the top of the chassis 144 and serves as a
supporting base for the hydraulic cylinder 118. The handle assembly
150 can be attached to the chassis assembly 140 at the chassis 144.
The handle assembly 150 has two vertically mounted handle arms 152,
a crossbar handle 154 and a second set of gripping handles 156. The
crossbar handle 154 is a horizontally oriented bar that extends
from one handle arm 152 to the other. The handle arms 152 are
mounted directly to the chassis 144 to further isolate the chair
assembly 110 and provide a smoother ride for the user. The handle
arms 152 and gripping handles 156 can be extended to the rear to
give the caretaker more leverage for maneuvering the chair. A
locking device (not shown) can be fixed to the handle arms 152 to
allow locking the chair assembly 110 to the handle arms 152 for
added security in rough or uneven terrain. When unlocked, the chair
assembly 110 can rock back and forth and swivel up to 180.degree.
(one hundred and eighty degrees), unimpeded by the handle arms 152.
The gripping handles 156 curve downwards. The arrangement of the
crossbar handle 154 and the gripping handles 156 decreases fatigue
in the hands, wrists and forearms of the caregiver, as well as
providing better leverage options for greater control over the
chair, and safety in variable situations. The handle arms 152 as
depicted are formed of steel tubes. In other embodiments, the arms
152 can be solid and/or formed of rigid polymers or lighter
metals.
[0056] The forward wheel assemblies 159 are located at the front
end 128 of the chassis assembly 140 and are attached to the chassis
assembly via the forward suspension arms 142. The forward
suspension arms 142 are springs. There is a forward wheel assembly
159 on each of the right and left sides of the wheelchair 100. The
forward wheel assemblies 159 are suspension features that have
wheels cantilevered on the ends of springs. Each forward wheel
assembly 159 describes a caster mechanism and is provided with a
wheel 160; an axle 162; a set of forks 164 and a swivel mount 166
that is connected to the forward spring arm 142. The wheel 160 is
mounted to the forks 164 at the axle 162 and is in turn connected
to the suspension arm 142 at the swivel mount 166 that is seated on
top of the forks 164. Each suspension arm 142 can be connected to
the chassis 140 at a mounting point 165. The suspension arm 142
functions as a spring for greater comfort to the user and
caregiver. The swivel mount 166 allows the wheel to rotate freely
for quick turning and pivoting. The front wheel diameter FWD is
approximately 8 inches (eight inches). In an embodiment, each front
wheel 161 is filled with foam under pressure for a softer ride and
puncture protection. In other embodiments, the wheels can be hard,
pneumatic and filled with air or another gas and dimensioned larger
or smaller. More generally, the size of the wheels and/or the
structure and material of tire and hub construction are highly
variable in a manner clear to those of skill. The hubs can be
solid, spoked, wire, or a combination of such. The tires can be any
acceptable thickness suitable for the terrain being traversed.
According to various embodiments, the wheels can be interchangeable
and wheel sets can be provided for various applications (e.g.
indoor versus outdoor travel).
[0057] The rear suspension assemblies 158 are suspension features
that have wheels cantilevered on the ends of springs. The
suspension assembly 158 includes a rear spring arm 170 that is
curved and describes a portion of an Euler spiral. The spring arm
170 connects with a rear wheel 172 at an axle 174. The rear wheel
can be filled with foam under pressure for a softer ride and
puncture protection. In an embodiment, a disk brake 176 is mounted
with the rear wheel 172. The illustrative disk brake 176 is
actuated by a hand control (not shown) that causes brake pads to
come in contact with the disk brake 176. The hand controls include
a locking mechanism to act as static full time wheel locks when the
wheelchair needs to be locked in place.
[0058] A footrest 190 is transversely mounted to a pair of footrest
support arms 192 that are mounted to the chassis assembly 140. The
footrest support arms 192 curve upward. The support arms 192 are
telescoping, and can be extended or retracted without removing them
from the chassis. This enables the caregiver to have more secure
and safe access to the user during user ingress and egress from the
chair. The footrest 190 can be mounted so it swivels for further
comfort and adjustment.
[0059] FIG. 2 depicts an illustrative wheelchair 200 in a second
embodiment. The wheelchair 200 includes a spring suspension
assembly 210 that functions as a spring. The seat 112 is the seat
of FIG. 1. The front wheel assembly and rear wheel are also the
same as in FIG. 1. The spring 212 differs from FIG. 1, wherein the
rear spring arm 170 was shaped to describe an Euler spiral in part.
In FIG. 2, the same spring 212 is connected to both front and rear
wheels. The spring 212 is a suspension member that includes various
spring arrangements that are clear to those of ordinary skill. The
material of the spring can be steel, carbon fiber, polymer-based, a
composite or another like material. The spring can have a
cross-section profile that describes a triangle, square, a hexagon,
or another polygonal shape. Main cross member 220 is a transverse
mounted cylinder that supports the spring suspension assemblies
210. A vertical pillar 222 is connected to the main cross member
220 and supports the seat 112. The pillar can be adjusted to
different heights as set forth above. The main cross member and
pillar are depicted as being circular in shape with regard to their
cross-section profile. In another embodiment, the main cross member
and pillar can have a cross-section profile that describes a
square, a hexagon, or another polygonal shape. The material used to
form the main cross member and pillar can be wood, a polymer, a
metal (for example, aluminum, steel, titanium or a composite), a
carbon fiber structure or composite material that is rigid, light,
strong and compliant to shock. Footrest 230 is connected to the
chassis 220 by a pair of footrest support arms 232. In an
embodiment, the footrest can swivel and is extendible in the
telescoping manner of the footrest in FIG. 1. A pair of rear axles
240 connects their respective rear wheel 172 to spring 212.
[0060] The main cross member 220 determines the center of gravity
depending on where it is located along the suspension spring path
(the path describes a segment along the length of the spring). It
is expressly contemplated that the main cross member can be
adjustably positioned with regard to the spring suspension
assemblies 210 and that it can be unlocked, repositioned and
re-locked into place in response to various terrain features and
user comfort desires. This repositioning can increase or reduce the
responsiveness in the spring suspension, resulting in a more
cushioned or stiffer ride. Moving the main cross member forward or
back redistributes the center of gravity (the point at which the
entire weight of a body can be considered as concentrated so that
if supported at this point the body would remain in equilibrium in
any position). As shown in the embodiment of FIG. 2, the spring
tension to the rear of the main cross member is stiffer, while the
spring that is forward of the main cross member is more flexible,
allowing the wheelchair to absorb shocks and jolts from uneven
terrain. The main cross member is the main structural component to
mount the suspension springs and no other support is needed for the
framework. This allows greater front and rear access for the
caregiver than conventional wheelchairs.
[0061] The vertical pillar 222 (seat base) is the mount for the
seat 112 and is attached to the center of the main cross member
220. This is the only contact point and structural relationship
between the seat and suspension chassis. The suspension chassis is
comprised of the spring suspension assemblies, the main cross
member 220, and the wheels. This arrangement enables each wheel to
act independently of the other, resulting in a four wheel
independent suspension. This isolation of the consumer/user
contributes to the elimination of harsh jolts and movement due to
terrain. The chair in this embodiment can be swiveled back and
forth as the chair shown in FIG. 1. It also provides for different
chairs to be exchanged as consumer needs and tastes change over
time. It is contemplated that seats with different padding,
appearance and features can be interchanged using a common mounting
and locking device (not shown) at the top of pillar 222. Separating
the chair from the suspension chassis can result in greater comfort
for the consumer/user. The gripping handles 156 can be adapted to
different chairs and can be extended to the rear to give the
caretaker more leverage for maneuvering the chair. A seat can be
custom ordered and applied by the manufacturer--such seat can be a
commercially available seat design (for example, a conventional
desk chair (e.g. the wellknow Aeron.RTM. chair line or an
automotive seat (e.g. the well-known Recaro.RTM. seat system)), or
can be a custom-built seat that is adapted particularly to the
user's body/needs--as such the seat can include various add-ons,
such as arm/head/neck rests, controls, and the like. A plurality of
seats can be provided to the user/consumer--suitable for various
situations/activities (e.g. an indoor seat and an outdoor seat). To
exchange a particular seat, the user/consumer (or appropriate
caregiver) detaches the seat 112 from the base and attaches a new
seat 250 to the base. Any electronic/pneumatic controls provided on
the seat can be connected via appropriate leads and plug connectors
routed through or on the base.
[0062] The main cross member design allows a chassis to be designed
for the weight and ride characteristics most suitable for the
terrain, conditions and overall ride comfort required by the
consumer and caregiver. This enables confidence and relaxation for
the consumer and caregiver, providing a smoother ride and a more
stable and safe environment. A smoother ride for the consumer
results in an easier effort by the caregiver, who is providing
motive force for the chair and its occupant. This can be related to
how individuals perceive the ride of a car and whether it is "firm"
or "soft". [0058] The suspension springs can be constructed of the
same materials as the main cross member, or another material,
dependent on spring properties, weight ratios, and terrain required
by the consumer and caregiver. Likewise, the spring length, cross
section design, and width can be changed, depending on spring
properties, weight ratios, and terrain required by the consumer.
This provides for modification of the suspension chassis to meet
the physical requirements of a greater number of consumers and a
wider range of terrain conditions and features. Changes in the
consumer's physical needs over time can be met by modifications to
the suspension chassis and positioning of the main cross member,
aiding in the maneuverability of the chair. Such changes can also
be made to optimize the maneuverability of the chair by caregivers
of different sizes and strengths.
[0063] The spring assemblies allow for the four wheels to interact
with the terrain independently. Independent suspension reaction
isolates the chair from sharp shocks and jolts, and enhances the
consumers' comfort and safety. The independent suspension reaction
also allows the consumer and caregiver greater control and access
over a wider range of terrain. When the caregiver has to negotiate
a step or a curb, and must raise the front wheels off the ground,
the spring facilitates a more consistent lever action, minimizing
the consumer's feeling of being about to tip over and giving the
caregiver greater confidence in negotiating the step or curb
without incident. The spring suspension absorbs shock, reducing the
jolt experienced when placing the front wheels back down after
passing over a step or curb, alleviating the consumer's dread of
feeling like they are about to be ejected from the seat. The spring
suspension also allows the caregiver more control when pulling the
chair backwards over a tall obstacle by softening and increasing
the apex of the rear wheels. The spring suspension provides for an
easier and more comfortable negotiation of smaller obstacles, for
example, uneven sidewalk panels or uneven ground.
[0064] It is contemplated that the action of the spring assemblies
can be moderated by a suspension spring tensioner, as shown in FIG.
3. The illustrative spring tensioner 302, 304 is a device that can
be mounted on either spring, or mounted on both springs. The spring
tensioner is a device for adjusting the tension of the springs,
allowing a fine tuning of the spring tension and providing greater
structural support. This provides for a custom spring rate for the
different weight ratios of consumers, as well as allowing more
flexibility for terrain changes. When the location of the main
cross member in relation to the suspension spring assemblies is
established, the spring tension can be fine tuned using the spring
tensioner device. The forward spring tensioner 302 is mounted with
one end on the spring and the other on the main cross member, on
the forward edge.
[0065] The rearward spring tensioner 304 is located with one end on
the spring and the other end on the main cross member, on the
rearward edge. The facility to match a consumer's environment to
the desired ride feel for the consumer and caregiver is
accomplished using the spring tensioner by varying the distance
between the attachment points on the main cross member to the
attachment points on the suspension springs. The spring tension is
adapted to accommodate variable terrain conditions. When such are
anticipated, for example, over obstacles or broken ground, the
suspension spring tensioner can be lengthened in the rear to cause
the spring to become stiffer in response and shortened in the front
to alleviate sharp shocks and jolts to the chair. A more responsive
rear spring can assist the caregiver in raising the front end by
pushing downward on the handles. Alternatively, if the wheelchair
is to be employed in a nursing home or hospice environment for long
periods of time, residing and/or traversing primarily smooth and
even floor surfaces, then the suspension spring tensioner can be
shortened to allow the suspension spring to deliver a soft feel to
the user's ride. In such instances, the spring tensioner serves to
reinforce the structure. It is contemplated that the spring
tensioners can be provided as part of a kit with the wheelchair
from the manufacturer or distributor (or from an after-market
supplier), and can optionally include pairs of spring tensioners of
differing sizes and/or strengths.
[0066] FIG. 4 is a top view of the wheelchair of FIG. 2. The rear
wheels 172 are shown as connected to the respective springs 212 at
axles 240 so that the wheels are outside of the respective springs.
The swivel mount 166 allow for free rotation of the front wheels
160 relative to the springs 212.
[0067] FIG. 5 is a bottom view of the wheelchair of FIG. 2. The
handles 156 extend into the seat 112 and are locking. The support
arms 232 extend into the footrest 230. As noted above, the seat can
be removed and exchanged for a seat with a different shape, for
example, a seat having arm rests, a lap belt or other
restraints.
[0068] It should be clear that the embodiments of the wheelchair
described above provide a personal mobility platform that performs
with greater cushioning and versatility of suspension. The
variability of angular orientation for the chair in the first
embodiment provides for greater comfort of the consumer. The
adjustability of the spring tension facilitates greater versatility
in movement of the chair over various terrains and obstacles. The
locking handle promotes easier movement and control over the chair.
The independent nature of the chair and chassis/suspension provides
enhanced ergonomic and economic benefits and increased design
flexibility.
[0069] II. Coil Spring Suspension
[0070] A wheelchair 600 with a suspension that utilizes coil
springs to dissipate and/or absorb energy during movement is shown
in an exploded view in FIG. 6, according to an illustrative
embodiment. The wheel chair 600 describes a mobility system that is
comprised of three assemblies; a chassis assembly 601 describes an
inverted T-shape and is comprised of a center tube 602, a pair of
counter-posed spindles 604, a T-post 606 and a seat bracket 607.
The wheelchair 600 includes a pair of rear wheels 610 that are each
attached at a hub 611 to the rear portion of a suspension assembly
626. A chair assembly 619 is mounted on top of the chassis assembly
601 and is comprised of a set of handlebars 620 that are attached
to a seat 622 that is mounted on top of the seat bracket 607. The
seat 622 is a molded contoured structure that can be provided with
an upholstered cover for comfort and additional support. The seat
622 can also be customized for a particular user using computer
modeling to adapt to the particular physical contours of the
occupant. The wheelchair as shown is dimensioned according to the
proportions of an average sized adult, and in other embodiments, it
is contemplated that the size of the wheelchair system can be
proportionately larger or smaller, depending on the size of the
user (for example, smaller in the case of a child and larger for an
overweight or very tall adult). In a further embodiment, it is
contemplated that the seat 622 can be provided with internal
heating coils for warmth. The structural composition of the seat
622 is a rigid polymer and can be formed of natural or synthetic
materials. The seat 622 can be readily removed from the seat
bracket 607 and can be replaced or exchanged for a different seat
or chair. The traditional wheelchair uses the seat as a stressed
piece of the frame, severely limiting ergonomic and safety options.
The wheelchair as shown separates the functions and relationship of
the seat and frame of the traditional wheelchair by removing the
seat or chair as a stressed piece of the frame. A footrest 624 is
attached to the seat 622 by a set of footrest support arms 625. A
suspension assembly 626 is mounted to the wheelchair 600 at each
spindle 604 and each suspension assembly 626 includes a rear arm
assembly 630, a front arm assembly 632, a connection channel 634, a
caster wheel 636, a shock tower 638, a shock assembly 640 and a
rear wheel 610. A center of gravity adjuster 642 is located between
the chair 622 and the top of the seat bracket 607.
[0071] With regard to center tube 602, it is the main and central
support structure for the chassis. The center tube 602 is hollow to
save weight and provide an area for the shoulder of the spindles
604 to insert and attach to the center tube 602. The center tube
603 can be constructed of aluminum, steel, carbon fiber,
polymer-based, a composite or another like material. The spindles
604, T-Post 606 and shock towers 638 are attached to the center
tube 602. The integration of these components in this arrangement
allows energy and forces acting on the chassis to be dissipated
through the interaction of these components, isolating these forces
from the chair, user, and caregiver. The center tube 602 and
attached components together define a main cross member that allows
a chassis to be designed for the weight and ride characteristics
most suitable for the terrain, conditions and overall ride comfort
required by the consumer and caregiver. This enables confidence and
relaxation for the consumer and caregiver, providing a smoother
ride and a more stable and safe environment. A smoother ride for
the occupant results in an easier effort by the caregiver, who is
providing motive force for the chair and its occupant. This can be
related to how individuals perceive the ride of a car and whether
it is "firm" or "soft". The spindles 604 attach to the center tube
602 at a shoulder that inserts into the outer end of the center
tube 602 and is locked by a bolt to prevent rotation. The spindles
604 can be constructed of aluminum, steel, carbon fiber,
polymer-based materials, a composite or another like material. The
spindles 604 support the rear arm assembly 630, the front arm
assembly 632, the shock tower 638, the chassis assembly 601 and the
chair assembly 619.
[0072] The T-Post 606 isolates the chair from the chassis and
suspension elements. This is the only contact point and structural
relationship between the seat 622 and the chassis assembly 601 and
suspension assembly 626. The T-Post 606 is rotatable with respect
to the center tube 602 and can lock at various positions by means
of a pin to change the entire chair angle orientation. This range
of motion can be selected by the occupant or the occupant's
caregiver. This allows an occupant the ability to change pressure
points on their body during long term use, to change the angle of
repose depending on social situations, and, to provide medical
benefits relating to edema common in long term use of traditional
wheelchairs. In another embodiment, the T-Post 606 is constructed
with a foot lever for the caregiver to exert leverage on the
chassis. The material of the T-Post 606 can be aluminum, steel,
carbon fiber, polymer-based, a composite or another like
material.
[0073] Each of the rear wheels 610 attaches to a rear arm assembly
630 via a sealed roller bearing and axle. The outer diameter OD of
a rear wheel 610 is approximately 14'' to 16'' (35.5 cm-40.6 cm)
(-+1''). In other embodiments, the outer diameter OD can be greater
or lesser. The wheelchair 600 as shown uses a significantly smaller
diameter rear wheel 610 than a traditional wheelchair for the
following reasons. First, the occupant for this wheelchair depends
solely on a caregiver for motion due to the occupant's loss or
reduction of arm and hand muscle coordination and/or functionality.
Larger diameter wheels can interfere with caregiver direct access
to the occupant of the chair. The "Occupant" is herein defined as
the passenger of the wheelchair that is occupying the seat 622. The
"Caregiver" is defined as an attendant to the occupant and the
provider of motive force for the wheelchair and its occupant. The
rear wheels 610 of the illustrative wheelchair are of a medium size
relative to other wheelchairs and this sizing provides complete
access for the caregiver from all degrees of angular orientation
relative to the occupant, particularly from the sides. In an
embodiment, the wheelchair 600 is not collapsible sideways, as with
traditional wheelchairs. The illustrative wheelchair 600 collapses
by folding the seat back 670 onto the seat 622. The rear wheels 610
are of a medium size and smaller than traditional wheelchairs, so
the profile of the illustrative wheelchair is relatively lower when
collapsed than a traditional wheelchair, providing for a more
compact profile during transportation. The chair can be removed for
a smaller profile during transportation. It is contemplated that a
removable vehicle seat can be retro-fitted to mount on top of the
chassis, so that it can be removed from the vehicle and placed onto
the chassis. The rear wheels 610 comprise a spoke structure 672,
hubs 611 and tires 674. The rear wheels 610 and tires 674 can be of
any material depending on uses required by the occupant or
caregiver. In an embodiment, each rear wheel 610 is filled with
foam under pressure for a softer ride and puncture protection. In
other embodiments, the rear wheels 610 can be hard, pneumatic and
filled with air or another gas and dimensioned larger or smaller.
More generally, the size of the wheels and/or the structure and
material of tire and hub construction are highly variable in a
manner clear to those of skill. The hubs 611 and spoke structures
672 can be solid, spoked, wire, or a combination of such. The tires
674 can be any acceptable thickness suitable for the terrain being
traversed. According to various embodiments, the rear wheels 610
can be interchangeable and wheel sets can be provided for various
applications (e.g. indoor versus outdoor travel).
[0074] Handlebars 620 can be adjusted for multiple orientations of
height, length and angles to provide multiple locations and angles
for the caregiver to grip, propel and maneuver the wheelchair 600.
The handlebars 620 provide multiple positions to mount bicycle type
levers for a rear disc brake system (not shown), controlled with
either one or two levers (two to control the right and left rear
independently). Proper leverage is a must for caregiver safety,
efficiency, and comfort. The caregiver can desire proper and
comfortable hand and wrist angles for effective maneuvering and to
protect that caregiver from potential hand and wrist injuries. The
handlebar 620 describes a crossbar handle and the gripping handle
reduces fatigue in the hands, wrists and forearms of the caregiver,
as well as providing better leverage options for greater control
over the chair, and safety in variable situations. The handlebar
620 as depicted are formed of steel tubes. In other embodiments,
the arms can be solid and/or formed of rigid polymers or lighter
metals. This handlebar 620 may be locked in place in any position
moving forward or backward to facilitate caregiver needs.
[0075] The chair assembly 619 is rotatable in a range of motion of
90.degree. (ninety degrees) to the right of left of an axis drawn
from the front end of the wheelchair to the rear end. This
corresponds to a swivel action in a range of motion of 180.degree.
(one hundred and eighty degrees) from left to right, and back. It
is contemplated that the orientation of the chair relative to axis
can be maintained by locking the swivel action with a locking
device, for example, a locking lever or detent button with stops at
45 degree increments. As previously stated, a unique feature of the
wheelchair 600 as shown is modular nature of the design, separating
the chair assembly 619 from the chassis assembly 601. The
wheelchair 600 is composed of modules that can be interchanged to
serve the needs of the occupant. Different seats 622 can be
exchanged as consumer desires and tastes change over time. It is
contemplated that a plurality of seats 622 with different padding,
appearance and features can be interchanged using a common
mounting. A handle 623 is a controlled locking device for the
center of gravity adjuster the T-post 606. Handlebars 620 can be
adapted to different chairs and can be extended to the rear to give
the caretaker more leverage for maneuvering the chair. A seat 622
can be custom ordered and applied by the manufacturer--such seat
can be a commercially available seat design (for example, a
conventional desk chair (e.g. the well-known Aeron.RTM. chair line
or an automotive seat (e.g. the well-known Recaro.RTM. seat
system)), or can be a custom-built seat that is adapted
particularly to the occupant's body/needs--as such the seat can
include various add-ons, such as arm/head/neck rests, controls, and
the like. A plurality of seats can be provided to the
occupant/consumer--each suitable for various situations/activities
(e.g. an indoor seat and an outdoor seat). To exchange a particular
chair assembly 619, the occupant/consumer (or appropriate
caregiver) detaches the Chair from the T-post 606 and attaches a
new seat to the T-post 606. Any electronic/pneumatic controls
provided on the seat can be connected via appropriate leads and
plug connectors routed through or on the chassis assembly 619,
T-post 616, and seat 622.
[0076] The footrest 624 is attached to chair assembly 619 by the
footrest support arms 625. The attachment point allows the footrest
624 to swivel and change angles in coordination with the movement
of the wheelchair 600. The footrest 624 is integrated with the
design and is not detached during ingress and egress of the
occupant. This eliminates frustration and time by the caretaker to
remove and replace traditional footrests before or after moving the
occupant. The footrest 624 enables the caregiver complete access to
the front of the chair when providing ingress and egress to the
occupant. The footplate 624 folds up against the footrest support
arms 625 and the footrest 624 can then be released to drop down
along a radius and rest completely under the front edge of the seat
622 against the T-post 606. This enables the caregiver to have more
secure and safe access to the occupant during occupant ingress and
egress from the wheelchair. During use, the footrest 624 is pulled
forward and is locked in position. In another embodiment, the
footrest support arms 625 are telescoping, and can also be extended
or retracted without removing them from the chassis assembly 601.
The footrest 624 can be constructed of aluminum, steel, carbon
fiber, polymer-based, a composite or another like material.
[0077] A rear arm assembly 630 is at each side of the chassis
assembly 619. Each rear arm assembly 630 includes a sealed roller
bearing at the rear to accommodate an axle connecting to the rear
wheel 610 and sealed roller bearings in the end of the spindle 604
that are sized and dimensioned to match the diameter of the
spindle. These bearings (not shown) ensure that the suspension
system works without binding and unnecessary friction so that force
is efficiently transferred to the shock absorption system, and not
the chassis assembly. Each rear arm assembly 630 is constructed and
arranged to provide internal room to incorporate a rear disc brake
system on each rear wheel 610 for maximum control of the wheelchair
600. The illustrative disk brakes as described below are actuated
by a hand control or controls (not shown) that causes brake pads to
come in contact with the disk brakes. These hand controls can
include a locking mechanism to act as static full time wheel locks
when the wheelchair 600 needs to be locked in place. One end of the
shock assembly 640 is attached to the rearward section of the rear
arm assembly 630 at a position that is approximately over the
center point of the rear wheel axle, mounted to the hub 611. The
shock absorber mounting position can be adjusted by changing the
mounting point in the connection channel 634. Each connection
channel mounting point changes the suspension properties and the
height of the center tube 602, and thus, the seat height. This also
enables changes to the wheelbase (for example, shortening the
wheelbase) for different applications. The rear arm assembly 630
can be constructed of aluminum, steel, carbon fiber, polymer-based,
a composite or another like material.
[0078] The front arm assembly 632 is a suspension member that, like
the rear arm assembly 630, both supports the wheelchair 600 and
provides dissipation and absorption of energy from movement. There
are two front arm assemblies 632, one on either side of the chassis
assembly 601. Each front arm assembly 632 includes sealed roller
bearings in the end of the spindles 604 that are sized to match the
diameter of the spindle. These bearings (not shown) ensure that the
suspension system works without binding and unnecessary friction so
that force is efficiently transferred to the shock absorption
system, and not the chassis assembly. One end of the shock assembly
640 is attached to the frontward section of the front section of
the front arm assembly 632 just rearward of the mounting point for
the caster wheel 636. The shock absorber mounting position can be
adjusted by changing the mounting point in the connection channel
634. Each connection channel mounting point changes the suspension
properties and the height of the center tube 602. The front arm
assembly 632 can be constructed of aluminum, steel, carbon fiber,
polymer-based, a composite or another like material.
[0079] The connection channel 634 is a structure that is U-shaped,
having two sidewalls that include a plurality of aligned holes that
are evenly spaced for attachment of the ends of the shock assembly
640. The connection channels 634 are used to determine the correct
shock absorber mounting position depending upon the needs of the
occupant and caregiver. The connection channels 634 can be
constructed of aluminum, steel, carbon fiber, polymer-based, a
composite or another like material.
[0080] The caster wheels 636 each are comprised of a set of forks,
a wheel and a bearing assembly and provides for quick turning and
front end maneuverability. In another embodiment, the caster wheels
can be replaced with an omnidirectional wheel. The diameter FWD of
a caster wheel 636 is approximately 5 inches (five inches). In an
embodiment, each wheel can be filled with foam under pressure for a
softer ride and puncture protection. In other embodiments, the
wheels can be hard, pneumatic and filled with air or another gas
and dimensioned larger or smaller. More generally, the size of the
wheels and/or the structure and material of tire and hub
construction are highly variable in a manner clear to those of
skill. The hubs can be solid, spoked, wire, or a combination of
such. The tires can be any acceptable thickness suitable for the
terrain being traversed.
[0081] According to various embodiments, the wheels can be
interchangeable and wheel sets can be provided for various
applications (e.g. indoor versus outdoor travel).
[0082] The shock tower 638 is a connection point for the front arm
assembly 632 and the rear arm assembly 630. The shock tower 638
enables each front arm assembly 632 and the rear arm assembly 630
to move independently to absorb the force energy of impact from
obstacles imparted to the arms through the caster wheel 636 and
rear wheels 610. The shock tower 638 is securely locked to the
spindles 602 by means of a keyway, spline, or pin mated to the
shock tower 638 and the spindle 602. By locking the shock tower 638
to the spindle 602 and locating the shock assembly 640 attachment
points at the same location at the top of the shock tower 638,
energy that is imparted to the front arm assembly 632 and rear arm
assembly 630 by encountering an obstacle is absorbed by the shock
assemblies 640 and dissipated before any remaining force acts on
the spindles 604 and center tube 602. By attaching the shock
assemblies 640 to the top of the shock tower 638 as shown, energy
is controlled and diminished which differs from other suspension
systems in that those systems are primarily designed to transfer
energy from the front to the rear or the rear to the front, not to
dissipate and remove energy from the chassis system. Removing
energy imparted to the chassis assembly by encountering an
obstacle, not just relocating it to some other point on the
wheelchair, is essential for the comfort of the caregiver and
occupant and is unique to the wheelchair as shown. The shock tower
638 mechanism and chassis design on the wheelchair as shown also
reduces the rocking motion of the chair inherent with four wheel
independent suspension systems. The shock tower 638 provides that
each front and rear arm assembly can be tuned independently
depending on the type of terrain and environment in which the
wheelchair as shown is used. This is truly an independent system
with each separate wheel having the ability to be tuned to the
caregiver and/or occupant's desires. The shock tower 638 can be
constructed of aluminum, steel, carbon fiber, polymer-based, a
composite or another like material.
[0083] Shock assemblies 640 are mounted to each front arm assembly
632 and rear arm assembly 630, as set forth above. In illustrative
wheelchair 600, the shock assemblies 640 can be independently tuned
for each arm. The length of the shock assemblies 640 can be
adjusted by use of a threaded mechanism on the shock assembly to
adjust their performance, as set forth more fully below. In another
embodiment, the shock assemblies 640 can be gas filled and they can
be mounted underneath the suspension arms to provide more caregiver
access to the front of the wheelchair 600. In a further embodiment,
the under mounted gas shock assemblies can be traction shocks
instead of compression shocks. The shock assemblies can be
constructed of aluminum, steel, carbon fiber, polymer-based, a
composite or another like material.
[0084] The center of gravity adjuster 642 is a center of gravity
mechanism common to most wheelchairs that move from the front to
the rear. This provides the ability to change the center of gravity
and thus the ratio of percentage of weight loading the chassis
assembly from front to rear. Changing this ratio changes the feel
of the ride provided by the chassis, chair, and suspension system
depending upon the caregiver and occupant's desires. The center of
gravity adjuster can be constructed of aluminum, steel, carbon
fiber, polymer-based, a composite or another like material.
[0085] In FIG. 7, the suspension assembly 626 includes a front coil
spring assembly 702 mounted at one end on the shock tower 638 and
at the other end at the connection channel 634 of the front arm
assembly 632. A rear coil spring assembly 704 mounted at one end on
the shock tower 638 and at the other end at the connection channel
634 of the rear arm assembly 630. In action, the rear wheel 610 is
attached to the rear arm assembly 630 and energy from the movement
of the rear wheel is dissipated and/or absorbed by the rear coil
spring assembly 704 as the front of the rear arm assembly 630 as it
pivots with regard to the spindle 604. In a like fashion, the front
caster 636 is attached to the front arm assembly 632 and energy
from the movement of the front caster wheel is dissipated and/or
absorbed by the front coil spring assembly 702 as the rear of the
front arm assembly 632 as it pivots with regard to the spindle 604.
The wheelchair has an overall length OL of approximately 36 inches
(91 cm) and an overall height OH of approximately 41 inches (104
cm).
[0086] In FIG. 8, a front view of the wheelchair 600 depicts each
front arm assembly 632 as being mounted to the outside of each
shock tower 638 and each rear arm assembly 630 mounted on the
inside of the shock tower 638, the "outside" being oriented in a
direction away from the chassis assembly 601, while the "inside" is
described as being closer to the chassis assembly 601. In another
embodiment, the front arm assembly 632 can be mounted to the inside
of each shock tower 638 and each rear arm assembly 630 can be
mounted on the outside of the shock tower 638.
[0087] With regards to FIG. 9, an upward and downward motion 902 of
the front arm assembly 632 causes a corresponding motion 904 of the
front coil spring assembly 702 to elongate or compress the coil
spring. In a like fashion, an upward and downward motion 910 of the
rear arm assembly 630 causes a corresponding motion 912 of the rear
coil spring assembly 704 to elongate or compress the coil
spring.
[0088] A detailed view of the shock tower 638 with two attached
shock assemblies 640 is shown in FIG. 10. Each shock assembly 640
is connected at a pin 1002 located at the top end 1004 of the shock
tower 638. Each shock arm 640 is comprised of a strut 1006 that
includes a fork 1007 at the inner end 1008 and a through-hole 1010
at the outer end 1012. A pin 1014 connects the spring strut 1016 to
the fork 1007 at the outer end 1018. A rotatable ring 1020 is at
one end of a coil spring 1022 and can be rotated on a threading to
shorten or lengthen the amount of movement for the coil spring. A
fixed forward stop 1024 is located in proximity to the shock tower
638 and arrests the movement of the coil spring 1022. The shock
tower is provided with a keyed hole 1030 that is a connection point
for the spindle 604.
[0089] A detailed view of the chassis assembly 619 is depicted in
FIG. 11. The seat mounting support 607 is shown with a plurality of
mounting holes 1102 for bolts (not shown) that can removably secure
the chair assembly 601 (not shown).
[0090] The suspension assembly 626 and a portion of the chassis
assembly are shown in FIG. 12. A pin 1201 connects a strut 1006
with the connection channel 634 by removably locking into one of a
plurality of aligned holes that are evenly spaced. Movement of the
pin 1201 from one hole 1202 to another changes the amount of
movement in the shock assembly to stiffen or loosen the ride of the
wheelchair 600.
[0091] FIG. 13 is a side view of the chassis assembly 601. A handle
623 that moves in a range of motion 1302 locks and unlocks the
center of gravity adjuster 642 that can change the center of
gravity for the wheelchair 600 to adjust the quality of the ride
for the occupant.
[0092] The suspension assembly 626 and a portion of the chassis
assembly 601is shown in FIG. 14. During movement, the respective
rear arm assemblies 630 and front arm assemblies 632 move up and
down relative to the spindle 602, with each shock assembly 640
compressing or lengthening based on the spring tension and the
positioning of the struts 1006 in the aligned holes 1202 in the
connection channels 634.
[0093] FIG. 15 is a view of the wheelchair 600 with the chair
assembly 619 removed, with the chassis assembly 601 and suspension
assembly 626 remaining. The center of gravity adjuster 642 is shown
on top of the seat mounting bracket 607.
[0094] An optional caregiver foot lever 1602 is shown in FIG. 16.
The foot lever 1602 is connected to the T-post 606 at mounting
point 1604 that can be a welded connection. The foot lever 1602 is
placed so as to allow a caregiver to use force from one of their
feet to provide additional leverage to raise the front of the
wheelchair 600 by placing their foot on the foot lever 1602 and
pushing down. An additional option can be disc brakes mounted on
the rear wheels, utilizing existing bicycle brake technology with a
caliper handbrake mounted on the handle.
[0095] III. Gas Traction Shock System
[0096] A wheelchair 1700 with a gas traction shock system is shown
in FIG. 17, according to an alternative embodiment. The wheelchair
1700, in the manner described above, is divided into three assembly
groups of components: a chair assembly 1710, a chassis assembly
1720 and a suspension assembly 1730. A gas traction shock 1732 is
shown as attached at one end to a footrest support arm 1722 and at
the other end, to the underside of a seat support bracket 1724 and
provides tension for the footrest 1726. The illustrative embodiment
replaces the T-post of the above-described embodiment and instead
uses a "bridge" like chassis that rests upon a suspension assembly
that is comprised of two-part shock assemblies. This significantly
reduces weight and increases accessibility to the user. The
suspension functions remain the same as the first embodiment as
well as the function of the chassis to dissipate energy imparted by
encountering an obstacle. Each shock assembly is comprised of a
front arm assembly 1731 and a rear arm assembly 1733. Each arm
assembly is joined to the chassis assembly 1720 at the bottom 1727
of the chassis frame 1728. Gas traction shocks 1732 are located
under the front and rear arm assemblies, mounted at the bottom 1727
of the chassis frame 1728. As used herein, the gas traction shocks
1732 on the suspension assembly function as the coil spring shock
assemblies as set forth above.
[0097] FIG. 18 shows the suspension and chassis assemblies without
the chair assembly, according to the alternative embodiment. The
gas traction shocks 1732 are shown in their places mounted under
the suspension arms (front arm assembly 1731, rear arm assembly
1733).
[0098] FIG. 19 is a view of the wheelchair 1700 according to the
alternative embodiment, showing the location of the connecting
point 1902 located on the chassis frame 1728 for connection of the
front arm assembly 1731 and the rear arm assembly 1733. This is the
pivot point for the movement of those arm assemblies. At least one
of the two rear wheels can be provided with a disc brake 1903. A
seat angle adjuster 1904 can modify the angular orientation of the
seat.
[0099] FIG. 19A is an alternate embodiment with gas traction shocks
1732 wherein the gas traction shocks are located inside of the
suspension arm assemblies, rather than below (as set forth above in
FIG. 19). A front suspension arm 1960 with a front wheel 1962 is
provided with a gas traction shock 1732 that is secured at one end
at a point 1961 towards the front of the front suspension arm 1960
and at the other end at a point 1963 on the chassis frame 1728. A
rear suspension arm 1964 is provided with a gas traction shock 1732
that is secured at one end at a point 1965 towards the rear of the
rear suspension arm 1964 and at the other end at a point 1967 on
the chassis frame 1728. In a further embodiment, it is expressly
contemplated that the gas traction shocks can be located at points
above the suspension arm assemblies.
[0100] IV. Torsion Spring Shock Assembly
[0101] FIG. 20 shows a wheelchair 2000 that is comprised of three
component assemblies: a chair assembly 2010 that functions as
described above, a chassis assembly 2020 and a suspension assembly
2030. The suspension assembly 2020 includes a spindle 2022, a
torsion spring 2024, a rear arm assembly 2026 and a front arm
assembly 2028.
[0102] The torsion spring 2024 is shown in greater detail in FIG.
21. The torsion spring 2024 is wrapped around a sleeve 2023 that is
a hollow tube mounted on the spindle 2022. A pair of ends, 2025 and
2027, can be connected to respective arm assemblies (not
shown).
[0103] V. Independent Four Arm Suspension Assembly
[0104] A wheelchair with an independent suspension that includes an
assembly of four suspension arms is depicted in FIGS. 22-39. A
chassis assembly 2200 for a wheelchair is shown in FIG. 22. In an
embodiment, the chassis assembly 2200 is a single chassis plate
2202 of a material that is folded and/or molded into a shape that
resembles an upside down "U"(e.g., a "bridge") and includes a
relatively horizontal portion 2204 and two support portions 2206.
The material of the chassis plate can be a metal (for example,
aluminum), a metallic alloy (for example, steel) or a composite
material (for example, a carbon fiber product). In another
embodiment, the chassis can be constructed of tubular members. The
space under the chassis plate 2202 defines a space that can be used
for storage of objects (for example, personal care supplies,
medical equipment, electronic equipment, or other useful items).
The weight and dimensions of the chassis 2200 can vary depending on
the material used, the size and weight of the occupant. A midpoint
center axis 2208 is an axis drawn from front to back through the
center of the chassis plate 2202 and is perpendicular to the
orientation of the horizontal portion 2204. A vertical axis 2210 is
defined as an axis drawn on a line extending from the center of the
earth outwards and is perpendicular to the horizontal axis 2212 of
a surface. The chassis assembly 2200 is oriented such that it is
off-center relative to the vertical axis 2210. A set-off axis 2214
drawn through the support portions 2206 from a bottom point 2216
through the respective support portion 2206, such that it can be
midway between a front ("leading") edge 2218 and the back
("trailing") edge 2220 of the chassis, describes a setoff angle
.theta. with the vertical axis 2210. In an embodiment, the set-off
angle .theta. is approximately fifteen degrees (15o) (+3o). In
other embodiments, the set-off angle can be greater or lesser. A
mounting hole 2221 can be located near the bottom 2216 of the
chassis, and between the front edge 2218 and the set-off axis 2214.
The mounting hole 2221 is a hole on each suspension portion 2206
extending through the material of the chassis plate 2202 and
providing a mounting point for the connection of a front suspension
arm 2222 and a rear suspension arm 2224. The front suspension arm
2222 and the rear suspension arm 2224 are connected to each other
at an axle 2226 that resides within the mounting hole 2221. The
front suspension arm 2222 includes a front mounting hole 2223 for
mounting a front wheel (not shown). The rear suspension arm 2224
includes a front mounting hole 2225 for mounting a rear wheel (not
shown). The chassis assembly 2200 functions to provide a connection
between an occupant and the wheels, as well as a suspension element
to dissipate energy from jolts and movement. As a suspension
element, the chassis assembly 2200 defines a spring. The horizontal
portion 2204 is generally rigid, but is sufficiently flexible to
provide for upwards and downwards motion 2238 that is greatest in
the vicinity of the midpoint center axis 2208 and lesser towards
the suspension portions 2206. The suspension portions 2206 can flex
inwards and outwards with a limited range of motion 2240. The
effects of these various motions will be described more fully
below. In another embodiment, the front wheels 2302 can be omni
wheels, casters or another style of wheel. The rear wheels 2304 can
be solid wheels, spoked wheels, or with bladed spokes. It should be
noted that the wheelchair as depicted in an embodiment does not
include in its depictions arm rests for the seat or restraint
devices (for example, a seat belt harness), but it is contemplated
that such devices can be provided with the wheelchair, as set forth
above. Furthermore, as noted herein, the seats are exchangeable
with other seats and it is contemplated that more than one seat can
be provided with a chassis assembly as part of a kit.
[0105] The relationship of the chassis assembly 2200 with the rest
of the wheelchair 2300 is shown in FIG. 23 in an exploded view. The
chassis assembly 2200 is provided with a pair of relatively small
front wheels 2302 attached to the front suspension arm 2222 and a
pair of relatively larger rear wheels 2304 attached to the rear
suspension arm. The rear wheels 2304 can be slowed and/or arrested
by operation of a braking system 2305 (described more fully below).
A seat assembly 2310 is attached to a mounting pillar 2330 that is
itself mounted onto a chassis assembly 2200. The mounting pillar
2330 is a universal mounting device and facilitates the interchange
of seats. It is contemplated that the mounting pillar can include
interactive plates, magnets, or another connecting mechanism. The
chassis assembly 2200 includes the wheels 2302, 2304 and a pair of
shock absorbers 2262, 2264 that are mounted at a central mounting
point 2266 and define a suspension assembly. In the illustrative
embodiment, the shock absorbers 2262, 2264 are mounted below the
front and rear suspension arms 2222, 2224. The front shock absorber
2260 is attached at one end to the central mounting point 2266 and
at the other end at a mounting point 2261 on the front suspension
arm 2222 located at a place between the front mounting hole 2223
and the central mounting point 2226. The rear shock absorber 2264
is attached at one end to the central mounting point 2266 and at
the other end at a mounting point 2265 on the rear suspension arm
2224 located at a place between the rear mounting hole 2225 and the
central mounting point 2226. When the shock absorbers are mounted
below the suspension arms, the central mounting point 2266 is
situated below mounting hole 2221. It is expressly contemplated
that the placement of the mounting point 2266 can be modified and
moved (e.g., by providing several holes or a slot for the movement
of the mounting point within that slot). It is contemplated that
the positions of the shock absorber mounting points 2261 and 2265
can be adjustable along their respective suspension arms. In an
embodiment, the suspension arms can be constructed and arranged of
a semi-rigid composite material (for example, carbon fiber) that
dissipate energy through flexing upwards and downwards, with the
front and/or rear suspension arm being directly attached to the
axle.
[0106] Mounting pillar 2330 is an assembly that includes a
plurality of adjustment levers 2332 that including but not limited
to at least one of each of controls for adjusting the center of
gravity, the tilt of the chair assembly, a rotating mechanism for
rotating the chair assembly and a locking mechanism for locking in
place the chair assembly 2310. It is contemplated that these
mechanism actuations can be actuated by a torsion spring, an
electronic solenoid or via a wireless device with an application.
The chair assembly can include at least one footrest 2312 that is
connected to the seat 2313 by a footrest arm 2314 at a mounting
point 2316 located on a bottom surface 2317 of the seat 2313. A
handle assembly 2340 can be mounted to the seat back 2318.
[0107] FIG. 24 shows a chassis assembly 2200 wherein the shock
absorbers 2260, 2264 are situated above the suspension arms. When
the shock absorbers are mounted above the suspension arms, the
central mounting point 2266 is situated above mounting hole 2221.
The front shock absorber 2260 is attached at one end to the central
mounting point 2266 and at the other end at a mounting point 2402
on the front suspension arm 2222 located at a place between the
front mounting hole 2223 and the central mounting point 2226. The
rear shock absorber 2264 is attached at one end to the central
mounting point 2266 and at the other end at a mounting point 2404
on the rear suspension arm 2224 located at a place between the rear
mounting hole 2225 and the central mounting point 2226.
[0108] FIG. 25 is a schematic view of a chassis assembly 2200 with
wheels, showing that diameter of the wheels. As noted above, the
size and shape of the wheels can vary. In an illustrative
embodiment, a front wheel 2302 has a diameter DFW of approximately
8 inches (+3 inches) and a rear wheel 2304 has a diameter DRW of
approximately 16 inches (+2 inches). In other embodiments, it is
contemplated that the front and rear wheels can be smaller or
larger. The size of the wheels can affect the dissipation of the
energies from impacts. For example, when the front wheel encounters
an object head on, the front wheel diameter directly affects the
physics of chassis/suspension response to the introduction of
energy at impact and its dissipation thereafter. The larger the
wheel diameter, the less noticeable the impact; however, in certain
situations smaller diameter front wheels are desired. Smaller
diameter wheels absorb impact much quicker over time from the
moment of impact to actually starting the process of rising over
the object, transferring energy at a higher rate than larger
diameter wheels. The illustrative wheelchair mitigates the high
rate of energy transfer with smaller wheels by a) changing the
angle of the of the shocks from their attachment point on the
chassis to their attachment point on the respective suspension arm
at mounting point 2261 on the front suspension arm 2222 and at
mounting point 2265 on the rear suspension arm 2224, b) adjusting
the distance between the axle center point 2910 and mounting point
2266, and c) adjusting the properties of the shock absorbers.
[0109] FIG. 26 is a top view that shows the relative placement of
the wheels 2302, 2304, suspension arms 2222, 2224, and their
respective mountings, relative to the chassis assembly 2200. The
braking systems 2305 are depicted in an illustrative embodiment as
a disk brake system with brake shoes 2306. The braking system will
be described more fully below. The rear wheels 2304, braking
systems 2305 and rear suspension arms 2224 are attached to the
chassis assembly 2200 at the support portions 2206 on the outside
of the support portion 2206. The front wheels 2302 and front
suspension arms 2222 are attached to the chassis assembly 2200 at
the support portions 2206 on the inside of the support portion
2206. Conversely, the front suspension arms can be on the outside
of the support portion, and the rear suspension arms can be on the
inside of the support portion. Thus, the support portion 2206 is
between the suspension arms and wheels, and can better transmit and
dissipate evenly side-to-side force energies than if both front and
rear suspension arms and wheels were either inside or outside the
support portion. The front and rear wheels are independent of each
other and are mounted independently to the chassis, without direct
connections.
[0110] FIG. 27 is a front view of the chassis assembly 2200 with
wheels as depicted in FIG. 26. The front wheels 2302 can be placed
slightly inside of the rear wheels 2304 so as not to share the same
path relative to where the wheels meet the ground. The suspension
arms 2222, 2224 can be provided with bends 2702 that add a folding
to the suspension arms and this folding creates an additional
spring motion at the bends 2702 that can further dissipate lateral
force energy. The slightly inset front wheels create a second set
of tread marks within the marks of the outer wheels and this can be
advantageous when moving over broken terrain features. The
relatively narrower front reduces the turning radius and increases
the responsiveness of the wheel chair for the caregiver.
[0111] FIG. 28 shows a cross section along lines 28-28 of FIG. 26.
The support portion 2206 includes a hole 2802 that passes through
the material of the chassis plate 2202. Axle 2226 is situated
within hole 2802 and holes 2221 of the forward suspension arm 2222
and rear suspension arm 2224.
[0112] An illustrative wheelchair is shown with FIG. 29. Vertical
axis 2210 is oriented to the leading edge of the chassis plate
2202. A second vertical axis 2900 is defined as parallel to
vertical axis 2210 and drawn through the center of the mounting
pillar 2330 and through the seat 2313, at or near the center of
gravity. The set off angle of the support portion 2206 places the
second vertical axis 2900 (the approximate center of gravity)
behind vertical axis 2210. Horizontal plane 2902 is a plane drawn
across the seat bottom 2317 and is perpendicular to vertical axis
2210. The horizontal plane 2902 is located above the tops of wheels
2302, 2304. This allows the seat 2313 to fully rotate above the
wheels, without interference or obstruction. The length of the
support portions 2206 of the chassis plate 2202 determines how
flexible the bridge will be when reacting to forces. The greater
the length, the greater the flexibility of chassis plate 2202 (the
"bridge"). Conversely, the shorter the length, the less flexible
the chassis plate 2202 will be. Changing the setoff angle of the
support portion outward from a true vertical orientation can also
make the chassis plate 2202 more flexible. Thus, the chassis can be
"tuned" to the desires and conditions of the terrain, the occupant
and the caregiver, to adjust the "ride" of the wheelchair. In
summary, ride quality can be adjusted by a) varying the length of
the side portions of chassis plate 2202, b) changing the outward
angle of the side portions of chassis plate 2202, c) adjusting the
angle of the shock absorbers by moving the mounting point 2266 or
changing the relative distance between centerpoint 2910 of the axle
2226 and the shock mounting point 2266, d) adjusting the tension
properties of the shock absorbers, and e) replacing tires and/or
wheels with tires and/or wheels of different sizes, widths,
materials or tread. This allows the chassis to be specifically
tuned to the individual user and caregiver, and/or, enables a
generic product such that one chassis/suspension configuration can
serve a wide weight range of users. [00102] FIGS. 30 and 31 show a
wheelchair in two variants, one variant 3000 provided with a single
footrest arm 2314 and footplate 2312 and the other variant 3100
provided with two footrest arms 2314 and two footplates 2312.
Attachment of the footrest to the chair, rather than to the
chassis, reduces shock energy and isolates the feet and legs. With
reference to FIG. 30, a footrest 2312 is located between the front
suspension arms 2222 and provides support to the feet of the
occupant, both to support the feet and legs in a desired
orientation and to protect the feet from coming in contact with
features in the terrain being traversed. The footrest 2312 is
joined at the front end to a footrest arm 2314 at a junction 3010
that in an illustrative embodiment is a hinge. The footrest arm
2314 is joined to the seat bottom 2317 at a mounting point 2316.
The mounting point 2316 is an assembly for connecting the footrest
2312 and footrest arm 2314 to the seat 2313 and the rest of the
wheelchair. A receiving mount body 3002 includes a side hole 3006
on either side for receiving and retaining an axle 3004. The axle
3004 passes through a through-hole 3005 in the footrest arm 2314.
It is contemplated that the mounting point can include a locking
mechanism for holding the footrest arm 2314 in a desired
orientation. The footrest arm 2314 can include an arm support
assembly 3007 that is attached to the footrest arm 2314 at a front
mounting point 3008 and to the seat bottom 2317 at mounting point
3009. The arm support assembly 3007 provides smooth resistive
motion when raising and lowering the footrest and provides
adjustment by locking the footrest and footrest arm when raised or
lowered to the proper height, thereby increasing the comfort for
the occupant, and ease of adjustment for the caregiver.
[0113] FIG. 31 depicts a wheelchair variant 3100 with two each of a
footrest 2312, footrest arm 2314, and mounting point 2316. This
allows an occupant to place one foot on each of the footrests. It
is contemplated that orthopedic and/or comfort considerations can
result in each of the footrests 2312 being set at a different
height orientation.
[0114] FIG. 32 shows the dissipation of forces through the chassis
assembly 2200. As noted above, commercially available wheelchairs
include a seat fixed to the frame so as to define a fixed
interdependent unit. In the commercially available wheelchairs,
when impact force loads are transferred upwards through the frame,
through the seat, they impact the occupant. This is because the
seat is an integral part of the frame. In an embodiment, the
illustrative wheelchair more effectively incorporates an
independent four shock system (e.g., suspension arms with shock
absorbers) and a chair that is not a stressed member of the
chassis. When the illustrative wheelchair encounters and traverses
any rough terrain such as thresholds or for that matter any
irregularities, impacts are substantially reduced due to the
suspension system based on multiple shock absorbers on the chassis
and the chassis 2200 itself. Each suspension arm is independent and
rotatable where it attaches to the chassis plate 2202 at the
support portion 2206. The suspension arms 2222 and 2224 can rotate
3202 relative to axle 2226. The motion of each suspension arm is
dampened by shock absorbers, which helps absorb the energy of the
impact, as set forth above. This too allows the chair to
essentially float over any irregularity that the chair is rolling
over with very little of the impact force being transferred to the
occupant. Any impact on one or several wheels will cause all the
other wheels, arms, and shocks to react to counterbalance the
impact(s) and reduce the energy of the impact.
[0115] In an embodiment, the chassis 2200 can flex upwards and
downwards in a motion 3404. Furthermore, each side of the
wheelchair has a separate support portion 2206 and axle 2226. This
arrangement is different from commercially available wheelchairs,
wherein a single axle passes from one side of the frame to the
other and the rear wheels are thus locked relative to the frame. In
contrast, the illustrative independent axles allow independent
rotation of each suspension arm, thus, when a wheel encounters an
impact from an irregular surface, its relevant suspension arm is
allowed to rotate around the axle and the shock absorber softens
the blow by absorbing the impact. While each shock absorber acts
independently, the other suspension arms and shock absorbers reduce
the impact by carrying the impact forces through the suspension
system and not imparting it directly to the chassis as a stopping
point. For example, if a front shock absorber extends or compresses
due to an impact event, the opposing shock is allowed to remain
static or compress or extend by rotating around the axle. This
contains the force of the impact event within the lower shock and
arm system and not transmitted to the occupant. Each mounting point
for the shock absorbers and the axles can rotate and/or move
independently of each other, resulting in a smoother ride compared
to a commercially available wheelchair. For example, if a front
wheel 2302 encounters a terrain feature, the relevant suspension
arm attached to the wheel begins to move, dampened by the
respective shock absorber, which moves relative to it mounting
points.
[0116] This causes the shock energy from the impact to be absorbed
by the movement of the shock absorber and the movement of the
suspension arms. Remaining energy can be absorbed by the movement
of the chassis 2200. At each point, the impact energy is
decreasing. The larger the impact, the more the suspension system
engages and reacts at multiple various points. A single impact on a
single suspension arm results in a reaction by only that suspension
arm, whereas a larger object may cause all four arms to react with
each reaction having less and less energy. The more energy absorbed
by the suspension, the less energy is imparted to the chassis 2200,
and, by removing the chair as a stressed member of the frame, very
little energy from the impact is imparted to the occupant.
Furthermore, the reaction of the suspension is relative to the
amount of the impact, and avoids a back and forth motion (a
"rocking horse" motion). This reduces the possibility of the chair
tipping over sideways. The chair and its occupant assumes a level
orientation in all directions, left, right, front, back and
omnidirectionally. Variations in occupant weight and the terrain
can be accommodated by adjusting the location of mounting points
2261 and 2265 along their relevant suspension arms and increasing
or reducing the tension of each shock absorber.
[0117] FIG. 33 shows a tilting mechanism 3300 for a wheelchair,
according to an embodiment. The tilting mechanism 3300 is an
assembly that can include a tilting mechanism body 3302, a pivoting
axle 3304 that is attached to the side of the chair 2313, and a
locking device 3305 that is situated in a slot 3306 that can be
locked and unlocked, to allow pivoting movement of the tilting
mechanism. Movement of the tilting mechanism 3300 provides a
tilting motion that can tilt the chair 2313 forwards and backwards.
It is contemplated that a tilting mechanism can be included on one
side of the chair, or on both sides. The tilting mechanism provides
a system for adjusting the tilt of the seat for the occupant and
contributes to the comfort of the occupant, as well as the ability
for the caregiver to "tune" the ride by moving the center of
gravity forwards or backwards, to adjust to different terrain and
ground features.
[0118] FIGS. 34 and 35 describe various chairs that can be placed
upon the chassis 2200. In FIG. 34, a seat with a mesh seat 3400 is
depicted. The mesh can be a relatively tight mesh, or a more open
mesh. A mesh seat can be desired for comfort, weight, or for ease
of cleaning (for example, after an unanticipated personal leakage
event by the occupant). While all seats described above are
intended to be removable for cleaning and repair, as well as
replacement with a different chair, the mesh chair advantageously
can be rinsed off without having to remove it from the chassis. The
exemplary mesh chair 3400 includes a seat mount 3401 for removable
engagement with the chassis (not shown), a seat frame 3402, a back
frame 3404, and a mesh fabric 3408 attached to the frame.
[0119] FIG. 35 shows an optional race car style seat 3500. A race
car style seat 3500 includes a seat mount 3502 (not shown) and a
padded seat having sides 3503 and a covering 3504 that is designed
to resemble a race car seat and that may include logos, after the
manner of professional race car seats.
[0120] A seat with transfer boards is shown in FIG. 36. It is
contemplated that certain of the occupants might not be readily
removed from the wheelchair to another structure (for example, a
bed or a medical examining table). The transfer board seat 3600 is
an embodiment to facilitate movement of the occupant in and out of
the seat. A transfer board seat 3600 includes a seat mount 3602 for
engagement with a chassis (not shown), a seat 3604 and a seat back
3606. At least one transfer board 3608 is located at one side of
the seat 3604. In an embodiment, the illustrative transfer board
seat 3600 is provided with a transfer board 3608 on each side. The
transfer board 3608 is attached to the seat 3604 by a hinge device
3610. In operation, the caregiver unlocks the transfer board and
moves the board 3608 to a position that is co-planar with the seat
3604. The occupant can now be shifted across the transfer bed to
another structure. Once the occupant has been transferred to
another structure, the transfer board 3608 can be returned to its
upright position. The ability to vertically raise and lower the
seat allows the caregiver to align the seat and transfer board so
that lateral movements from seat to another structure can be made
without having to raise or lower the occupant by physically
lifting.
[0121] The caregiver handles 3700 are shown in FIG. 37. In an
embodiment, the handle 3700 is a tubular structure that is formed
by bending and can be coated with a layer of comfort material (for
example, a foam polymer). Each handle 3700 is provided with one or
more attachment members 3702 for engagement with the wheelchair
seat back (not shown). A horizontal cross bar 3704 provides a
handle for grasping while providing motive force to the wheelchair.
Segments 3706 provide a space between the cross bar 3704 and the
back of the seat for the comfort of the caregiver's hands, as well
as additional leverage for maneuvering the wheelchair. Segment 3706
can be used as an additional handle area. It is contemplated that
the handle can be raised or lowered, or be provided with an angular
adjustment to change the placement of the handle to match the
ergometrics of the caregiver.
[0122] It should be clear to one of ordinary skill that the above
described wheelchair and its variants provide a system based on an
independent suspension for greater energy dissipation, comfort for
the occupant and control for the caregiver. The above embodiments
describe a wheelchair that overcomes the disadvantages of the prior
art by providing a mobility system that had greater stability, ease
of use and safety for both the occupant and caregiver. The
increased adaptability of the chair for the caregiver can improve
the caregiver's burden in moving the occupant, thereby improving
the relationship between caregiver and occupant.
[0123] The foregoing has been a detailed description of
illustrative embodiments of the invention. Various modifications
and additions can be made without departing from the spirit and
scope of this invention. Features of each of the various
embodiments described above may be combined with features of other
described embodiments as appropriate in order to provide a
multiplicity of feature combinations in associated new embodiments.
Furthermore, while the foregoing describes a number of separate
embodiments of the apparatus and method of the present invention,
what has been described herein is merely illustrative of the
application of the principles of the present invention. For
example, the wheels can be solid, foam filled or pneumatic. The
springs can be springs that are a simple curve or provided with a
complex curve, for example, a curve that describes an Euler spiral.
The pillar mounted seat can be attached to a chassis assembly or to
a main cross member. A spring tensioner can be provided for fine
tuning the spring tension. The seat of the chair can be
interchangeable with like chairs or chairs of a different design,
shape and padding.
[0124] There are no limits to the type and functionality of chairs
that can be fit to the chassis to satisfy ergonomic needs of the
caregiver and user. It is not necessary to dispose of the entire
wheelchair over time as the occupant's needs change; simply replace
the seat or modify the chassis suspension as needs dictate. Also,
as used herein various directional and orientational terms such as
"vertical", "horizontal", "up", "down", "bottom", "top", "side",
"front", "rear", "left", "right", and the like, are used only as
relative conventions and not as absolute orientations with respect
to a fixed coordinate space or system, such as the acting direction
of gravity. Likewise, where the term "substantially" or
"approximately" is employed with respect to a given measurement,
value or characteristic, it refers to a quantity that is within a
normal operating range to achieve desired results, but that
includes some variability due to inherent inaccuracy and error
within the allowed tolerances of the system (e.g. 1-5%).
Accordingly, this description is meant to be taken only by way of
example, and not to otherwise limit the scope of this
invention.
* * * * *