Wheel chair abstract
The invention relates to a small vehicle, particularly a wheel
chair, comprising a chassis having a monocoque-type main body to
which arms for supporting wheels are coupled and at which a seat
component can be attached. The main body is designed as a monolith
and preferably is manufactured from an extruded profile of aluminium
or an aluminium alloy, or is made of wound sheet metal or of plastic.
Four arms for two freely pivotable supporting wheels and two driving
wheels are springably coupled to said main body.
Wheel chair claims
We claim:
1. A wheel chair comprising: a chassis having a monocoque-type
main body designed as a monolith, four arms for supporting wheels
are springably coupled to the main body; and the main body receives
a seat component.
2. The wheel chair as claimed in claim 1, wherein the main body
is made from an extruded profile.
3. The wheel chair as claimed in claim 1, wherein the main body
is made of aluminium or an aluminium alloy.
4. The wheel chair as claimed in claim 1, wherein the main body
is made of wound sheet metal.
5. The wheel chair as claimed in claim 1, wherein the main body
is made of plastic.
6. The wheel chair according to claim 1, wherein two freely pivotable
wheels and two driving wheels are provided.
7. The wheel chair according to claim 6, wherein said freely pivotable
wheels and said driving wheels are detachably mounted at said arms
via quick release devices.
8. The wheel chair according to claim 6, wherein said driving wheel
has a hub motor.
9. The wheel chair according to claim 6, wherein said driving wheel
is driven by an electric motor.
10. The wheel chair according to claim 1, wherein said seat component
is detachably mounted at said main body via a quick release device.
11. The wheel chair according to claim 1, wherein one or several
storage batteries are mounted on said main body.
12. The wheel chair according to claim 11, wherein said one or
several storage batteries are mounted at one or both of two opposite
sides of said main body.
13. The wheel chair according to claim 11, wherein one or several
storage batteries are mounted on said main body, wherein, in case
of operation with only one storage battery, the one storage battery
is mounted in a central position with respect to a center axis of
the vehicle, whereas, in case of operation with several storage
batteries, the several storage batteries are mounted symmetrically
with respect to the center axis of the vehicle.
14. The wheel chair according to claim 1, wherein said seat component
comprises a seat, a seat back, at least one arm rest, and a foot
rest, and the seat is detachably mounted on said main body as a
complete unit via a quick release device.
15. The wheel chair according to claim 14, wherein said seat component
is foldable.
16. The wheel chair according to claim 1, wherein said four arms
comprise front arms for supporting pivotable wheels, and said front
arms are designed as springably supported dual arms defining a caster
of said pivotable wheels that remains substantially constant over
the range of travel of a spring system defined by said springable
coupling.
17. The wheel chair according to claim 7, wherein said quick release
device for detachably mounting said pivotable wheel at a front arm,
said quick release device comprises a plug-in axle extending perpendicular
to the ground
18. The wheel chair according to claim 1, wherein said four arms
comprise rear arms for supporting driving wheels, and said rear
arms are designed as longitudinal arms which are supported at said
main body via a spring/shock absorber unit.
19. The wheel chair according to claim 1, wherein said main body
defines interface for electric circuits at mounting locations defined
by the group consisting of mounting locations for driving wheels,
said seat component, and storage batteries.
20. The wheel chair according to claim 1, wherein said seat component
is mounted to said main body, said seat component being constructed
as a body frame and having a monocoque construction, and the seat
component being rotatable about 180.degree..
21. A wheel chair comprising: a chassis having a monocoque-type
main body designed for use as a single piece; four arms for supporting
wheels, wherein the arms are springably coupled to the main body;
and the main body comprises a quick release for a seat component.
22. A wheel chair comprising: a chassis having a monocoque-type
main body designed for use as a single piece; four arms for supporting
wheels, in which the arms are springably coupled to the main body;
and the main body supports a seat component.
Wheel chair description
BACKGROUND OF THE INVENTION
[0001] The invention relates to a small vehicle, particularly a
wheel chair comprising a chassis having a monocoque-type main body.
[0002] Wheel chairs, including those which are driven by a motor,
usually comprise a wheel chair frame in which a seat is integrated,
two wheels which can be driven and two wheels which can be either
freely pivoted or steered by a motor wherein said wheels are directly
coupled to said frame. The drivable wheels can be driven manually
via hand rims or driven by a motor. Such wheel chairs often comprise
a folding mechanism which allows folding of the wheel chair frame
in order to reduce the overall size for the purpose of transport
of the wheel chair. A wheel chair of this kind is for instance disclosed
in EP 0 790 049 A2.
[0003] Wheel chairs of the kind as explained above are rather unsuitable
for outdoor operation, that is for operation outside houses and
particularly on uneven tracks, for instance tracks in fields or
woods. The frame construction as described above has only a relatively
low stability. Moreover, direct coupling of the wheels to a pipe
frame only allows a suspension which is insufficient for uneven
tracks since the only spring system is usually the one provided
by the pneumatic tires.
[0004] Wheel chairs having acceptable driving and performance characteristics
for outdoor operation are also known. However, the amount of time,
work and effort needed for dismantling such wheel chairs for the
purpose of transport is not acceptable.
[0005] There is a need for a small vehicle, particularly a wheel
chair which has sufficient stability suitable also for outdoor operation
as well as a drivability suitable for outdoor operation and, at
the same time, can be dismantled so that transport thereof is possible
in a typical trunk of an automobile.
SUMMARY OF THE INVENTION
[0006] The small vehicle according to the present invention has
a chassis having a monocoque-type main body. Four arms for supporting
the wheels are springably coupled to the main body and a seat component
is mounted at said main body. While according to the prior art discussed
above a seat is integrated in a pipe frame and the wheels are directly
coupled to said pipe frame, in case of the small vehicle according
to the present invention the monocoque-type main body performs the
function of supporting the suspension. The main body has sufficient
stability to perform this supporting function.
[0007] The main body is designed as a monolith. This means that
the main body has a block-like structure which provides sufficient
stability, is relatively light weight and has corresponding attachment
points for supporting the arms and for receiving the seat component.
For this, the main body for example can be manufactured from an
extruded profile, i.e. it can be provided in the form of a hard
alloy extrusion or extruded shape made of aluminium or an aluminium
alloy. Moreover, the main body can be made of a suitable plastic,
a compound material, or of wound sheet metal.
[0008] Two freely pivotable wheels and two driving wheels can be
detachably mounted at said at said arms, preferably by means of
quick release devices. The driving wheels preferably comprise a
hub motor, that is a motor which is provided in the region of the
wheel hub. Accordingly, there is no necessity of providing a drive
train from the vehicle frame to the driving wheels. The torque for
driving the vehicle is provided in the hub motor and the stationary
portion of the hub motor merely must be supported at the corresponding
arm via a suitable support element to enable driving operation.
[0009] Electric motors are particularly suited for driving such
small vehicles. Storage batteries necessary for power supply can
be mounted at the main body, preferably via suitable quick release
devices which allow quick and easy change of the storage batteries.
Connection points for the storage batteries can be provided at opposite
sides of the main body. Moreover, there can be provided several
connecting points for selective operation with one or several storage
batteries, wherein, in case the vehicle is to be operated with only
one storage battery, this storage battery is mounted in a central
position with respect to the center axis of the vehicle, while,
if the vehicle is to be operated with several storage batteries,
these storage batteries are mounted symmetrically with respect to
the center axis of the vehicle.
[0010] The seat component of the small vehicle according to the
present invention preferably comprises a seat, a back of seat and
foot rests as well as two arm rests and is provided as a complete
unit. This unit is adapted to be mounted to the main body and to
be dismounted therefrom by means of a quick release device. The
seat component can be foldable. Due to the modular structure of
the small vehicle the seat can be designed with particular view
to ergonomics so that also seat pans for seriously handicapped persons
can be used. Moreover, the seat component can be rotatably arranged
so that upon turning the seat by 180.degree. a vehicle having rear
wheel drive will become a vehicle which has front wheel drive.
[0011] The arms for supporting the freely pivotable wheels are
preferably designed as springably supported dual arms. This ensures
that the caster of the freely pivotable wheels remains essentially
constant over the entire range of spring, particularly in case the
freely pivotable wheels are coupled to the arms by means of plug-in
axles which extend vertically to the ground. In case there is only
a limited travel of the spring system, the front arms also can be
designed as mono-arms.
[0012] The arms provided for supporting the driving wheels are
preferably designed as longitudinally arranged arms which are supported
at the main body via a spring/shock absorber unit.
[0013] A small vehicle designed as a wheel chair as explained above
has excellent stability. The wheels may be springably supported
to also allow operation on uneven tracks. At the same time, the
structure and design of the wheel chair allow it to be dismantled
into single components, making it possible to transport the wheel
chair in the trunk of a common automobile. After the four wheels
are detached from the arms, which for instance, can be done very
easily if plug-in axles and quick release devices are used, and
after the seat component and, as the case may be, storage batteries
are removed, only the main body and the four arms, remain. This
module unit has a flat shape which can be easily transported. The
wheels and the storage batteries also can be easily stowed away
and the seat component can also be brought into a space-saving flat
form, if a folding mechanism is used.
[0014] Particularly in cases where electric motors are used as
driving units, the main body can have interfaces for electric circuits
at the connection points of the driving wheels and/or the seat component
and/or the storage batteries. A control panel, including a console,
can be provided at an arm rest of the seat component. Furthermore,
it is possible to provide wireless signal transmission between the
control panel and the driving wheels. If hub motors are provided,
a separate control unit may be provided for each hub motor. In that
case, it will not be necessary to provide wires for control signals.
If the storage batteries are attached to the main body, it will
only be necessary to provide power transmission to the hub motors.
[0015] If the storage batteries are also disposed adjacent the
wheel hubs of the driving wheels and a wireless signal transmission
for control signals is provided, it will not be necessary to provide
any wires between the frame and the wheels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the following description, the invention is further explained
in connection with a preferred embodiment making reference to the
drawing in which
[0017] FIG. 1 is a perspective representation of a vehicle where
the parts are taken apart in exploded view;
[0018] FIG. 2 is a perspective representation of the vehicle corresponding
to FIG. 1 wherein the main components except a control panel are
depicted as being assembled;
[0019] FIG. 3 is a perspective depiction of the wheel chair according
to FIGS. 1 and 2 where the seat component is omitted;
[0020] FIG. 4 is a depiction corresponding to FIG. 3 wherein an
additional protective cage is attached;
[0021] FIG. 5 is a side view of the representation according to
FIG. 3;
[0022] FIG. 6 is a side view of a freely pivotable wheel having
a climbing device in a position before a step is contacted; and
[0023] FIG. 7 is a representation corresponding to FIG. 6 in which
a step is negotiated.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] FIG. 1 shows a wheel chair as an embodiment of the present
invention in a so-called exploded view, i.e. with the parts taken
apart. The main body 10 is provided in the form of a hard alloy
extrusion or extruded shape made of an aluminium alloy 11. The hard
alloy extrusion 11 is closed at both longitudinal ends by corresponding
end plates 12 and respective bolts. Internal reinforcing members
(not shown) or other components, for instance switching units etc.
(not shown) can be provided in the essentially hollow inner space
of the main body 10. On the upper side 13 of the main body 10 there
is provided a receiving unit 14 which serves for mounting of a seat
component 50 by means of a quick release device which is not shown
in detail.
[0025] The seat component 50 comprises frame profiles which together
with fabric or upholstery provide a seat 51, a seat back 52, a foot
rest 53 and a strut 54 for mounting control panel 60. It is understood
that armrests (not shown) can be provided on both sides.
[0026] It is also clear that other structures are possible for
the seat component; for instance, a seat and a seat back and, as
the case may be, corresponding side parts. The whole seat component
50 can be provided as a monocoque structure and can have corresponding
connecting elements for connecting the seat component to the main
body or to a corresponding seat frame.
[0027] The seat component is provided with a folding mechanism
which allows the seat component 50 to fold when it is detached from
the main body 10 so that the seat can be easily transported as one
element of substantially flat shape.
[0028] On the left side and on the right side, with reference to
the driving direction of the vehicle, two front arms 20 and two
rear arms 30, respectively, are connected to the main body 10. The
rear arms 30 are designed as longitudinal arms which are supported
at the main body 10 by means of a spring/shock absorber unit 31.
The front arms 20 are designed as dual arms which are connected
to each other by a spring/shock absorber mechanism which is disposed
within the main body 10 and which is not shown in the drawings.
[0029] The two driving wheels 35 are coupled to the rear arms 30
via horizontally extending plug-in axles 36 and via quick release
devices which are not shown in detail. Two front wheels 25, which
are freely pivotable, are coupled to the front arms 20 via vertically
extending plug-in axles 26 and via quick release devices which are
also not shown in detail. As can be seen for instance from FIGS.
5 to 7, the position of the axis of rotation 27 of the front wheel
25 is offset with respect to the position of the plug-in axle 26.
Consequently, a caster is provided so that the front wheels 25 are
always oriented towards the driving direction when the vehicle is
driving straight ahead. The steering of the wheel chair is effected
by separate control of both driven rear wheels 35. Preferably, the
driving force is provided by hub motors, i.e. electric motors which
are provided in the hub region of the wheels (but are not shown
in detail). Steering commands are input via a control panel 60.
[0030] The front arm 20 (illustrated as a dual arm) is designed
in a way that the caster of the front wheel 25 remains substantially
constant over the entire range of travel of the spring system.
[0031] One or several storage batteries 70 can be hooked to the
main body 10 via quick release devices. The quick release devices
for securing the storage batteries 70 comprise interfaces for electric
circuits which provide electric connection of the storage batteries
70 to the hub motors.
[0032] A protection device in the form of a protective cage 80
is, preferably detachably, attached to the main body 10.
[0033] A climbing device 28 is provided at each of the front wheels
25. There is a pair of climbing devices 28 for each front wheel
25 which is supported on both sides of each front wheel 25 and biased
in a way so that under normal operational conditions they are in
a position which is depicted in FIG. 6. The climbing device 28 can
be pivoted over a certain distance in the direction indicated by
arrow A in FIGS. 6 and 7 in the direction of rotation of the wheel
with the pivotal axis indicated at reference number 29.
[0034] For the sake of simplicity, only one front wheel 25 is depicted
in FIGS. 6 and 7 in order to explain the function of the climbing
device 28. When the wheel chair travels in the direction of a curb
with the front wheel leading, the climbing device 28 initially is
in its upper pivotal position due to the bias force of the spring.
When the climbing device 28 gets in contact with curb 90, the climbing
device 28 is pivoted in the direction of rotation of the front wheel
25 due to the driving force provided by the driving wheels. As a
result, the front wheel 25 is lifted until it gets in contact with
the curb in an appropriate position so that upon further travel
of the vehicle the curb 90 can be negotiated.
[0035] Due to the fact that the climbing devices 28 are directly
coupled to the freely rotatable front wheels 25, such climbing devices
28 are always in a suitable orientation with respect to an obstacle,
particularly in such cases where a curb or another step is approached
at an angle. It is clear that the climbing device also can be directly
coupled to the main body.
[0036] The seat component 50, the storage batteries 70, the rear
wheels 35 and the front wheels 25 can be removed by means of simple
quick release devices for dismantling the wheel chair. After being
removed, the seat component 50 can be folded. Accordingly, single
components are provided which can be transported in a space-saving
manner and which can be accommodated in the trunk of a common automobile.
The ability to be easily dismantled further provides that the single
components have a relatively low weight so chat the components can
be easily stowed away. The provision of quick release devices facilitates
dismantling of the wheel chair also for technically untalented persons
and without any tools.
[0037] Even though the wheel chair of the present invention is
easily dismantled, it is suitable for outdoor use. It combines the
comfort of four spring-suspended wheels and the stability required
for outdoor operation with the low weight and transportability of
a common indoor wheel chair.
[0038] Although the invention has been described with reference
to exemplary embodiments, it is not limited thereto. Rather, the
appended claims should be construed to include other variants and
embodiments of the invention which may be made by those skilled
in the art without departing from the true spirit and scope of the
present invention. |