U.S. patent application number 09/825598 was filed with the patent office on 2001-08-16 for fun-kart with two powered wheels.
Invention is credited to Baker, Peter M..
Application Number | 20010014569 09/825598 |
Document ID | / |
Family ID | 27268552 |
Filed Date | 2001-08-16 |
United States Patent
Application |
20010014569 |
Kind Code |
A1 |
Baker, Peter M. |
August 16, 2001 |
Fun-kart with two powered wheels
Abstract
A vehicle for leisure or competitive use has a chassis 50
supporting two wheels 12 on a common axis 14 which can be
independently driven by respective battery-powered electric motors
22 or internal-combustion engines or be independently kept
stationary. Two laterally-spaced castor wheels 18 are disposed in
one plane at a longer distance on one side of the axis, and are
mounted on the chassis by independent resilient suspension means
52, 54, 56, 58, 60 and 62. Two laterally-spaced castor wheels 20
are disposed in another plane, which is inclined to that plane in
which the castor wheels 18 are disposed, at a shorter distance on
the other side of the axis, and are mounted directly on the
chassis. The vehicle is provided with a seat 32 and the disposition
of the seat and the batteries relative to the axis is so arranged
that there is insufficient weight on the castor wheels 18 to resist
the torque exerted at the wheels 12 during sudden acceleration as a
result of which the vehicle will perform a so-called "wheely"
whereby it rears up until the castor wheels 20 contact the ground
as shown in broken lines. The vehicle can also be caused to turn
rapidly in tight circles by appropriate independent control of the
motors or engines. Remotely-controlled toy vehicles can employ the
same principle of operation as the fun-karts described for carrying
occupants.
Inventors: |
Baker, Peter M.;
(Huddersfield, GB) |
Correspondence
Address: |
Trexler, Bushnell, Giangiorgi,
Blackstone & Marr, Ltd.
Suite 3600
105 West Adams Street
Chicago
IL
60603
US
|
Family ID: |
27268552 |
Appl. No.: |
09/825598 |
Filed: |
April 4, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09825598 |
Apr 4, 2001 |
|
|
|
09297113 |
Jun 14, 1999 |
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Current U.S.
Class: |
446/448 |
Current CPC
Class: |
A63H 17/004 20130101;
B62K 17/00 20130101; A63G 25/00 20130101; B62D 61/00 20130101; B62D
37/00 20130101; B62D 61/12 20130101; A63H 30/04 20130101 |
Class at
Publication: |
446/448 |
International
Class: |
A63H 017/26 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 1996 |
GB |
9622301.1 |
Aug 4, 1997 |
GB |
9716346.3 |
Oct 22, 1997 |
GB |
PCT/GB97/02916 |
Claims
1. A vehicle comprising a chassis having mounted thereon two
laterally-spaced independently power-driven and braked wheels
rotateable about a common axis, front stabiliser means spaced in
front of said axis, rear stabiliser means spaced behind said axis
and, with the vehicle on a horizontal plane with the front
stabiliser means and the power-driven wheels on said plane, the
rear stabiliser means having a support surface which is disposed
above said plane, the centre of gravity of the loaded vehicle, with
the vehicle operating on the horizontal plane, being disposed
between a first vertical plane containing said axis and a second
vertical plane parallel to said first plane and containing the
point of contact between the front stabiliser means and the
horizontal plane, said vehicle being configured such that the
driving force applied on the horizontal plane to the power-driven
wheels multiplied by the radius of said wheels is capable of
reducing to zero the weight supported at the point of contact
between the front stabiliser means and the horizontal plane, and
such that further increases in the driving force cause the vehicle
to rotate about said axis until the rear stabiliser means contact
the horizontal plane.
2. A vehicle according to claim 1, wherein the chassis is provided
with a seat so disposed that the centre of gravity of the vehicle
and an occupant of the seat in combination is adjacent to and in
front of the first vertical plane.
3. A vehicle according to claim 2, wherein control means for the
power-driven wheels are located within reach of the seat.
4. A vehicle according to claim 1, wherein the front stabiliser
means consist of at least one castor wheel.
5. A vehicle according to claim 1, wherein the front and rear
stabiliser means each consist of two laterally-spaced stabilisers
in order to reduce the possibility of the vehicle tipping
sideways.
6. A vehicle according to claim 1, wherein the front stabiliser
means are disposed at a longer distance than the rear stabiliser
means from said axis.
7. A vehicle according to claim 1, wherein the power-driven wheels
are driven by at least one internal combustion engine.
8. A vehicle comprising a chassis having mounted thereon two
laterally-spaced independently power-driven and braked wheels
rotateable about a common axis, front stabiliser means spaced in
front of said axis, rear stabiliser means spaced behind said axis
and, with the vehicle on a horizontal plane with the front
stabiliser means and the power-driven wheels on said plane, the
rear stabiliser means having a support surface which is disposed
above said plane, the centre of gravity of the loaded vehicle, with
the vehicle operating on the horizontal plane, being disposed
between a first vertical plane containing said axis and a second
vertical plane parallel to said first plane and containing the
point of contact between the front stabiliser means and the
horizontal plane, said vehicle being configured such that the
maximum driving force applied on the horizontal plane to the
power-driven wheels multiplied by the radius of said wheels is at
least equal to the weight of the loaded vehicle multiplied by the
horizontal distance of the centre of gravity of the loaded vehicle
from said axis to enable the loading on the front stabiliser means
to be controllably reduced to zero, and such that further increases
in the driving force cause the vehicle to rotate about said axis
until the rear stabiliser means contact the horizontal plane.
9. A vehicle comprising a chassis having mounted thereon two
laterally-spaced independently power-driven and braked wheels
rotateable about a common axis, front stabiliser means spaced in
front of said axis, rear stabiliser means spaced behind said axis
and, with the vehicle on a horizontal plane with the front
stabiliser means and the power-driven wheels on said plane, the
rear stabiliser means having a support surface which is disposed
above said plane, the centre of gravity of the loaded vehicle, with
the vehicle operating on the horizontal plane, being disposed
between a first vertical plane containing said axis and a second
vertical plane parallel to said first plane and containing the
point of contact between the front stabiliser means and the
horizontal plane, said vehicle being configured such that the
maximum driving force applied on the horizontal plane to the
power-driven wheels multiplied by the radius of said wheels plus
the inertia force multiplied by the vertical distance of the centre
of gravity of the vehicle above said axis when said centre is so
located is at least equal to the rolling resistance of the vehicle
multiplied by the radius of said wheels plus the weight of the
vehicle multiplied by the horizontal distance of the centre of
gravity of the vehicle in front of said axis so as to enable the
loading on the front stabiliser means to be controllably reduced to
zero, and such that further increases in the driving force cause
the vehicle to rotate about said axis until the rear stabiliser
means contact the horizontal plane.
Description
[0001] This invention relates to a vehicle which is primarily
designed as a fun-kart for leisure or competitive use, but which
may also be a remotely-controlled toy.
[0002] There are various kinds of fun-karts already in existence
which approximate to miniature motor-cars. They usually have four,
or occasionally three, wheels which normally remain in contact with
the ground, and the occupant's disposition relative to the plane of
the ground does not change. They are usually steered by operating a
steering wheel or handle-bar arrangement to turn the front wheel or
wheels.
[0003] There are also in existence electric wheel-chairs for the
disabled having two wheels on a common axis which can be
independently power-driven or kept stationary under the control of
a joy-stick for the purpose of steering, and two castor wheels
disposed not far in front of said axis. Such wheel-chairs sometimes
have elevating and/or reclineable seats, but the driveable wheels
and the castor wheels are intended to remain in contact with the
ground whilst, in order to prevent these wheel-chairs from
accidentally overturning rearwardly, they usually have stabiliser
means in the form of two small non-castoring wheels disposed behind
said axis a short distance above ground level. Another known design
of electric wheel-chair for the disabled has two wheels on a common
axis which can be independently power-driven or kept stationary
under the control of a joy-stick for the purpose of steering, and
two castor wheels disposed not far behind said axis, no stabiliser
means being provided.
[0004] Remotely-controlled toy vehicles are also well known.
[0005] The object of the present invention is to provide a novel
kind of vehicle in which its disposition, and that of its occupant
unless it is a toy, is deliberately variable relative to the plane
of the ground whilst exhibiting rapid turning and a higher degree
of manoeuvreability than a conventionally steered vehicle. To this
end, it utilises some of the features of electric wheel-chairs in a
very considerably modified form.
[0006] According to one aspect of the invention, a vehicle
comprises a chassis having mounted thereon two laterally-spaced
independently power-driven and braked wheels rotateable about a
common axis, front stabiliser means spaced in front of said axis,
rear stabiliser means spaced behind said axis and, with the vehicle
on a horizontal plane with the front stabiliser means and the
power-driven wheels on said plane, the rear stabiliser means having
a support surface which is disposed above said plane, the centre of
gravity of the loaded vehicle, with the vehicle operating on the
horizontal plane, being disposed between a first vertical plane
containing said axis and a second vertical plane parallel to said
first plane and containing the point of contact between the front
stabiliser means and the horizontal plane, said vehicle being
configured such that the driving force applied on the horizontal
plane to the power-driven wheels multiplied by the radius of said
wheels is capable of reducing to zero the weight supported at the
point of contact between the front stabiliser means and the
horizontal plane, and such that further increases in the driving
force cause the vehicle to rotate about said axis until the rear
stabiliser means contact the horizontal plane.
[0007] Preferably, the chassis is provided with a seat so disposed
that the centre of gravity of the vehicle and an occupant of the
seat in combination is adjacent to and in front of the first
vertical plane.
[0008] Preferably, also, control means for the power-driven wheels
are located within reach of the seat.
[0009] The front stabiliser means preferably consist of at least
one castor wheel.
[0010] Preferably, the front and rear stabiliser means each consist
of two laterally-spaced stabilisers in order to reduce the
possibility of the vehicle tipping sideways.
[0011] The front stabiliser means are preferably disposed at a
longer distance than the rear stabiliser means from said axis.
[0012] Preferably, the power-driven wheels are driven by at least
one internal combustion engine.
[0013] According to another aspect of the invention, a vehicle
comprises a chassis having mounted thereon two laterally-spaced
independently power-driven and braked wheels rotateable about a
common axis, front stabiliser means spaced in front of said axis,
rear stabiliser means spaced behind said axis and, with the vehicle
on a horizontal plane with the front stabiliser means and the
power-driven wheels on said plane, the rear stabiliser means having
a support surface which is disposed above said plane, the centre of
gravity of the loaded vehicle, with the vehicle operating on the
horizontal plane, being disposed between a first vertical plane
containing said axis and a second vertical plane parallel to said
first plane and containing the point of contact between the front
stabiliser means and the horizontal plane, said vehicle being
configured such that the maximum driving force applied on the
horizontal plane to the power-driven wheels multiplied by the
radius of said wheels is at least equal to the weight of the loaded
vehicle multiplied by the horizontal distance of the centre of
gravity of the loaded vehicle from said axis to enable the loading
on the front stabiliser means to be controllably reduced to zero,
and such that further increases in the driving force cause the
vehicle to rotate about said axis until the rear stabiliser means
contact the horizontal plane.
[0014] According to a further aspect of the invention, a vehicle
comprises a chassis having mounted thereon two laterally-spaced
independently power-driven and braked wheels rotateable about a
common axis, front stabiliser means spaced in front of said axis,
rear stabiliser means spaced behind said axis and, with the vehicle
on a horizontal plane with the front stabiliser means and the
power-driven wheels on said plane, the rear stabiliser means having
a support surface which is disposed above said plane, the centre of
gravity of the loaded vehicle, with the vehicle operating on the
horizontal plane, being disposed between a first vertical plane
containing said axis and a second vertical plane parallel to said
first plane and containing the point of contact between the front
stabiliser means and the horizontal plane, said vehicle being
configured such that the maximum driving force applied on the
horizontal plane to the power-driven wheels multiplied by the
radius of said wheels plus the inertia force multiplied by the
vertical distance of the centre of gravity of the vehicle above
said axis is at least equal to the rolling resistance of the
vehicle multiplied by the radius of said wheels plus the weight of
the vehicle multiplied by the horizontal distance of the centre of
gravity of the vehicle in front of said axis so as to enable the
loading on the front stabiliser means to be controllably reduced to
zero, and such that further increases in the driving force cause
the vehicle to rotate about said axis until the rear stabiliser
means contact the horizontal plane.
[0015] The invention will now be described, by way of example, with
reference to the accompanying diagrammatic drawings of which:
[0016] FIG. 1 is a plan view of one specific embodiment of a
fun-kart;
[0017] FIG. 2 is a side elevation of said one embodiment shown in
full lines with front castor wheels in contact with the ground and
in broken lines with rear castor wheels in contact with the
ground;
[0018] FIG. 3 is a plan view corresponding to FIG. 1 of another
specific embodiment of a fun-kart; and
[0019] FIG. 4 is a side elevation corresponding to FIG. 2 of said
other embodiment.
[0020] Referring now to FIGS. 1 and 2 of the drawings, one specific
embodiment of a fun-kart includes a chassis comprising a short rear
portion 10 which supports two wheels 12 on a common axis 14, and a
longer front portion 16 of a tubular space-frame type connected to
the rear portion 10 by hinge means (not shown) adjacent and
parallel to said axis and disposed a short distance on the front
side thereof. The chassis portions 10 and 16 are urged apart by
resilient means (not shown) thus providing a shock-absorbing
suspension system for the fun-kart. Stabiliser means comprising two
castor wheels 18 supported towards the front end of the chassis
portion 16 are disposed in one plane at a longer distance on the
front side of the axis 14, and stabiliser means comprising two
castor wheels 20 supported at the rear end of the rear chassis
portion 10 are disposed in another plane inclined to said one plane
at a shorter distance on the rear side of said axis. In other
words, with the vehicle on a horizontal plane which represents
level ground, a support surface of the rear stabiliser means is
disposed above said plane with the front stabiliser means and the
power-driven wheels 12 on said plane. The wheels 12 can be
independently power-driven in either direction of rotation or kept
stationary by respective electric motors 22 of permanent magnet
twenty-four-volt direct current type connected to the wheels by
respective worm-and-wormwheel speed reduction gearboxes 24 and
powered by two twelve-volt batteries 26, said motors and gearboxes
being of any suitable conventional state of the art kind. The
motors 22 provide regenerative braking. The motors 22, gearboxes 24
and batteries 26 are supported by the rear chassis portion 10, and
the distance of the batteries to the rear of the axis 14 is
variable to enable the balance, that is to say the weight
distribution, of the fun-kart to be adjusted having regard to the
weight of the occupants hereinafter referred to. The speed and
regenerative braking of the wheels 12 are controlled by a
twin-channel controller 28 of the type employed in electric
wheel-chairs, which enables the fun-kart to be steered and
controlled rapidly and precisely by a single joy-stick 30. A main
occupant's seat 32 with a back-rest 34 and a head restraint 36 is
secured at the rear of the front chassis portion 16, and said
portion has an integral roll-bar 38 to protect the main occupant if
the fun-kart should overturn. However, this is unlikely as the seat
32 is disposed very close to the ground in order to provide
stability when cornering. The seat 32 is also disposed just forward
of the axis 14 so that the weight of the main occupant, partially
counterbalanced by the batteries 26, normally holds the front
castor wheels 18 in contact with the ground. The centre of gravity
of the loaded vehicle, with the vehicle operating on the horizontal
plane, is disposed between a first vertical plane containing the
axis 14 and a second vertical plane parallel to said first plane
and containing the point of contact between the front stabiliser
means and the horizontal plane. A secondary occupant's seat 40 is
provided near the front end of the front chassis portion 16 above
the castor wheels 18. The disposition of the seat 32 and/or the
seat 40 relative to the axis 14 may be variable to assist in
adjusting the balance of the fun-kart. The controller 28 is secured
to one side of the front chassis portion 16 so that the joy-stick
30 is located within reach of the seats 32 and 40. At the front end
of the front chassis portion 16 there is fitted a pneumatic-tyred
wheel freely rotateable about an axis 44 which is substantially
vertical when the front castor wheels are in contact with the
ground. The wheel 42 is not intended to make any contact with the
ground, being provided to deflect the fun-kart safely away from
walls and the like, to guide the kart around corners on a track,
and to act as a shock-absorbing bumper in the event of a head-on
collision.
[0021] Referring now to FIGS. 3 and 4 of the drawings, another
specific embodiment of a fun-kart is in most respects similar to
the embodiment of FIGS. 1 and 2, and like parts are identified by
the same reference numerals. One difference is that a one-piece
chassis 50 is employed, each of the two castor wheels 18 being
mounted on the chassis 50 by independent resilient suspension means
shown in FIG. 4. One of said means is disposed at each side of the
chassis 50 and comprises an arm 52 which is pivoted at its rear end
at a point 54 on the chassis 50 and carries one of the castor
wheels 18 at its front end, and a telescopic strut 56 which is
urged into extended condition by a helical compression spring 58
and is connected between a point 60 on the chassis 50 and an
intermediate point 62 on the arm 52. Another difference is that the
wheels 12 are controlled by independent speed controllers and
associated electronic twist grips 64 best seen in FIG. 3 which are
located within reach of the seats 32 and 40. The twist grips 64 can
control both the direction of rotation and the speed of the motors
22, or alternatively they control only the speed and a
manually-operated switch is provided to reverse said motors.
[0022] In the operation of both specific embodiments hereinbefore
described, a single occupant can use either of the seats 32 and 40,
or two occupants can use both of said seats. When a single occupant
uses the main seat 32, or two occupants include a light-weight
person such as a child using the secondary seat 40, and the
dispositions of the seats 32 and 40 and the batteries 26 relative
to the axis 14 are adjusted as necessary to keep the front
stabiliser means resting lightly on the horizontal plane when the
kart is stationary, the driving force applied on the horizontal
plane to the power-driven wheels 12 multiplied by the radius of
said wheels is capable of being increased to reduce to zero the
weight supported at the point of contact between the front
stabiliser means and the horizontal plane, further increases in the
driving force causing the vehicle to rotate about the axis 14 so
that the kart rears up until the rear stabiliser means contact the
horizontal plane as shown in broken lines in FIG. 2 so as
dramatically to change the longitudinal inclination, and also in
the case of the seat 40 the height, of the occupant or occupants
relative to the ground. More explicitly, the kart is able to rear
up as just described when the driving force applied on the
horizontal plane to the power-driven wheels 12 multiplied by the
radius of said wheels is at least equal to the weight of the loaded
vehicle multiplied by the horizontal distance of the centre of
gravity of the loaded vehicle from the axis 14 to enable the
loading on the front stabiliser means to be controllably reduced to
zero, further increases in the driving force causing the vehicle to
rotate about the axis 14 until the rear stabiliser means contact
the horizontal plane. Deceleration will cause the kart to fall back
onto its front castor wheels 18. The weight distribution
characteristics of the fun-kart are such that up to 100 percent of
its weight can be concentrated over the power-driven wheels 12,
affording it far better traction than any conventional
two-wheel-driven vehicle. Regardless of whether it is stablised on
its front or rear castor wheels, or even balanced on the wheels 12
alone, the fun-kart can be caused to turn in progressively tighter
circles by slowing, stopping or, where suitable provision is made,
reversing either one of the motors 22. An occupant of the seat 40
will then experience a feeling of being centrifuged. Where suitable
provision is made, the fun-kart can also be driven and turned in
reverse by appropriate control of the motors 22, but "wheelies" are
not then possible. Acceleration, deceleration, turning and
reversing can all be controlled from either of the seats 32 and 40,
but the controls will of course feel to be reversed for an occupant
of seat 40. The fun-kart can be used for leisure or for competitive
racing, and is well adapted for use on very undulating terrain.
[0023] Numerous modifications are possible within the scope of this
invention. The secondary seat 40 can be omitted. The relative
positions of the batteries 26 and the main seat 32 can be reversed
when the secondary seat 40 is provided, in which case the
arrangement of the seats can be such that occupants of both seats
can experience a "wheely" and the feeling of being centrifuged. A
three-seat configuration can also be provided, with one seat in the
middle and one seat at each end. The two electric motors 22 can be
replaced by two internal-combustion engines of any suitable
conventional, state of the art kind, especially two-stroke engines
which can desirably rotate at very high speeds, together with
associated clutch/brake means or by a single electric motor or a
single internal-combustion engine in conjunction with suitable
means for independently driving and braking the wheels 12. The
joy-stick or the twist grips can be replaced by other control means
such as a steering wheel, foot pedals, and hand levers. The speed
reduction gearboxes can be of other than worm gear type, and can be
replaced by belt and/or chain speed reduction means. The fun-kart
can be designed so as to be readily dismantled, either to
facilitate its transportation or to allow its drive means to
operate other attachments. As well as adjustable batteries and seat
or seats, ballast weights can be used to balance the fun-kart for
different numbers and weights of occupants and or to maximise the
inherent ability of the fun-kart to negotiate very undulating
terrain. Such ballast weights can be adjustable in position, and
this can be effected by motorised means while the fun-kart is in
motion. The height of the rear castor wheels 20 above the ground
when the front castor wheels 18 are in contact with the ground can
be adjustable to vary the angle to which the fun-kart rears up when
a "wheely" is performed. The rear castor wheels can incorporate
resilient suspension means as well as or instead of the front
castor wheels. Instead of providing a suspension hinge adjacent to
the axis 14, it can be provided adjacent to the front castor wheels
18. If desired, there need be no suspension means at all. A single
castor wheel disposed on the longitudinal centre-line of the
fun-kart can be employed at the front and/or at the rear, with a
corresponding reduction in cornering ability. Stabiliser means in
the form of skids can take the place of the front and rear castor
wheels when the fun-kart is used on sand, snow or other soft or
slippery surfaces. The fun-kart can be small in size for a child,
or large and very powerful for more than one adult. A
remotely-controlled toy vehicle can employ the same principle of
operation as the fun-kart.
[0024] In another modification, the fun-kart can be designed so
that the centre of gravity of the loaded vehicle is located at an
appreciable height above the axis 14, by seating the occupant at an
appreciable height or possibly by making provision for him to
stand. This will increase the magnitude of the sensations he will
experience. In this case the inertia force acting horizontally on
the vehicle at the centre of gravity becomes much more significant
by virtue of the height of the centre of gravity, and must be taken
into account in designing the kart to render it capable of
performing a "wheely". Thus the maximum driving force applied on
the horizontal plane to the power-driven wheels 12 multiplied by
the radius of said wheels plus the inertia force multiplied by the
vertical distance of the centre of gravity of the vehicle above the
axis 14 when said centre is so located must be at least equal to
the rolling resistance of the vehicle multiplied by the radius of
said wheels plus the weight of the vehicle multiplied by the
horizontal distance of the centre of gravity of the vehicle in
front of the axis 14 so as to enable the loading on the front
stabiliser means to be controllably reduced to zero, further
increases in the driving force causing the vehicle to rotate about
the axis 14 until the rear stabiliser means contact the horizontal
plane. The rolling resistance is normally not significant and has
therefore been ignored hitherto, but has been included in the
preceding sentence to provide a more complete explanation of the
dynamics to which the vehicle is subjected.
* * * * *