U.S. patent number RE33,675 [Application Number 07/307,790] was granted by the patent office on 1991-08-27 for motorized wheel chair.
This patent grant is currently assigned to Sinties Corporation. Invention is credited to Alva L. Young.
United States Patent |
RE33,675 |
Young |
August 27, 1991 |
Motorized wheel chair
Abstract
A motorized wheel chair is provided comprising a chassis having
two rear wheels and one front wheel mounted thereon. The front
wheel is steerable by a handlebar. The rear wheels are driven by an
electric motor, coupled to a gearbox, for reducing the speed of the
wheel chair. The gearbox drives a friction drive assembly which is
engageable with the rear wheels and also is coupled to the
handlebar such that one of the rear wheels will be disengaged
depending upon which direction the handlebar is turned. The device
is provided with a switch which cuts power to the device when a
change in surface elevation of a desired amount is detected either
in front of or behind the device. A second switch may be provided
to stop the vehicle upon contact with a foreign object. A third
switch may be activated remotely to stop the device. Also, the
chassis is adjustable in length, such that as a child grows the
device may be adjusted accordingly.
Inventors: |
Young; Alva L. (Tulsa, OK) |
Assignee: |
Sinties Corporation (Tulsa,
OK)
|
Family
ID: |
26975927 |
Appl.
No.: |
07/307,790 |
Filed: |
February 7, 1989 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
709766 |
Mar 8, 1985 |
04641720 |
Feb 10, 1987 |
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Current U.S.
Class: |
180/167; D12/131;
180/6.2; 180/169; 180/216; 180/342; 180/907 |
Current CPC
Class: |
A61G
5/045 (20130101); B62D 11/08 (20130101); A61G
5/1051 (20161101) |
Current International
Class: |
A61G
5/04 (20060101); A61G 5/00 (20060101); B62D
11/08 (20060101); B62D 11/06 (20060101); B62D
011/08 (); B60K 028/00 () |
Field of
Search: |
;180/6.2,6.24,6.26,216,907,279,214,274,74,907,275,276,277,278,280,11,16,199,342
;446/175 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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677816 |
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Jun 1939 |
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DE2 |
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2724553 |
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Dec 1978 |
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DE |
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3128112 |
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Feb 1983 |
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DE |
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1204349 |
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Sep 1960 |
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FR |
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1129915 |
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Oct 1968 |
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GB |
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Primary Examiner: Bertsch; Richard A.
Attorney, Agent or Firm: McCarthy; Bill D. Burdick; Glen
M.
Claims
I claim:
1. A motorized wheel chair for small children, comprising:
(a) a chassis;
(b) a front wheel, rotatably mounted on said chassis;
(c) a right rear wheel, rotatably mounted on said chassis;
(d) a left rear wheel, rotatably mounted on said chassis;
(e) a steering means, mounted on said chassis and connected to said
front wheel, for turning said front wheel;
(f) a gear reduction means, for limiting the speed of said wheel
chair, mounted on said chassis;
(g) a drive shaft, rotatably connected to said gear reduction
means, said drive shaft having a left friction drive roller and a
right friction drive roller fixedly attached thereto such that said
left and right friction drive rollers are engageable with said left
and right rear wheels, respectively;
(h) an electric motor, driveably connected to said gear reduction
means such that for every revolution of said drive shaft, said
motor will turn a greater number of revolutions;
(i) a throttle means, for controlling the speed of said motor,
connected to said motor;
(j) a shift means, for controlling the direction of said motor,
connected to said motor;
(k) a power source, mounted on said chassis and connected to said
motor;
(l) a seat, mounted on said chassis; and
(m) a clutch means, for selectively operating only said left rear
wheel during a right turn and only said right rear wheel during a
left turn, said clutch means being connectable between said
steering means and said drive shaft said clutch means further
comprising:
i. a right steering cable, connected at one end to said steering
means, and at the other end to a right clutch lever;
ii. a right clutch lever pivotably attached to said chassis,
attached to said right steering cable and attached to said drive
shaft such that, during a right turn, said right friction drive
roller is urged away from said right rear wheel;
iii. a left steering cable, connected at one end to said steering
means, and at the other end to a left clutch lever; and
iv. a left clutch lever pivotally attached to said chassis,
attached to said left steering cable and attached to said drive
shaft such that, during a left turn, said left friction drive
roller is urged away from said left rear wheel; and wherein said
gear reduction means is flexibly mounted to said chassis such that,
upon an application of force, said gear reduction means may twist
slightly on an axis generally perpendicular to said chassis and
then return to its original position upon the release of said
force. .Iadd.
2. A motorized wheel chair for a small child comprising:
a chassis;
seat means supported by the chassis for supporting the child;
wheel means for supporting the chassis;
drive and steering means for selectively driving and steering the
wheel means so that the wheel chair is caused to be moved along a
selected path by the wheel means in response to actuation by the
child;
detection means for sensing the presence of an object and for
preventing the drive means from driving the wheel means in the
direction of the sensed object; and
elevation sensing means for detecting a change in surface elevation
greater than a selected elevation difference and for stopping the
wheel chair upon detecting the selected elevation difference.
.Iaddend. .Iadd.3. The motorized wheel chair of claim 2 wherein the
detection means comprises:
front detection means attached to the wheel chair for sensing the
presence of an object and for preventing the drive means from
driving the wheel
means in a forward direction. .Iaddend. .Iadd.4. The motorized
wheel chair of claim 3 wherein the detection means further
comprises:
rear detection means attached to the wheel chair for sensing the
presence of an object and for preventing the drive means from
driving the wheel means in a reverse direction. .Iaddend. .Iadd.5.
The motorized wheel chair of claim 4 wherein the elevation sensing
means comprises:
front elevation sensing means supported by a forward portion of the
chassis for stopping the wheel chair upon detecting the selected
elevation
difference. .Iaddend. .Iadd.6. The motorized wheel chair of claim 5
wherein the elevation sensing means further comprises:
rear elevation sensing means supported by a rearward portion of the
chassis for stopping the wheel chair upon detecting the selected
elevation difference. .Iaddend. .Iadd.7. The motorized wheel chair
of claim 2 wherein the drive and steering means comprises:
power means for selectively powering the wheel means. .Iaddend.
.Iadd.8. The motorized wheel chair of claim 7 wherein the power
means has at least one gel cell battery. .Iaddend. .Iadd.9. The
motorized wheel chair of claim 8 wherein the wheel means comprises
at least one pair of wheels and wherein the motorized wheel chair
further comprises:
motor means connected to the wheel means for selectively rotating
the wheels when energized by the battery. .Iaddend. .Iadd.10. The
motorized wheel chair of claim 9 further comprising:
charge means supported by the chassis for charging the battery.
.Iaddend. .Iadd.11. The motorized wheel chair of claim 2 further
comprising:
remote switching means for actuating the drive and steering means
from a remote locate. .Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates generally to motorized wheel chairs. More
particularly, this invention relates to motorized wheel chairs
suitable for use by small children.
2. Prior Art
Many devices have been designed and are now in use which aid the
physically or mentally challenged in moving from place to place.
Various motorized wheel chairs are now available for such use.
However, these devices are often unsuitable for use by small
children.
In order to provide a motorized wheel chair for small children,
especially those under five years of age, additional factors must
be taken into consideration. In order to circumvent the requirement
of constant adult supervision, the vehicle must incorporate a
number of safety features. A child must not be able to operate the
vehicle across sharp changes in floor elevation (e.g. steps). The
vehicle should operate at a very low speed and must be easy to
steer. Some protection should be provided to prevent damage to
furniture and other household fixtures. The vehicle must resist
overturning. It is also desirable that a supervising adult be
provided with some remote means for immediately stopping the
vehicle.
There are very few devices currently available which meet any of
the above criteria. This problem is compounded by the fact that
devices currently on the market are extremely expensive. Also,
current motorized wheel chairs for small children are useless when
the children outgrow them, thus requiring even greater costs for
replacement vehicles.
SUMMARY OF THE INVENTION
Considering the above, it is an object of this invention to provide
a motorized wheel chair which is suitable for operation by small
children.
It is another object of this invention to provide a motorized wheel
chair which cannot be operated across sharp changes in
elevation.
It is still another object of this invention to provide a motorized
wheel chair which will operate at a low speed and which is easily
steerable.
It is a further object of this invention to provide a motorized
wheel chair which incorporates a feature to prevent damage to
furniture and other household fixtures.
It is still a further object of this invention to provide a
motorized wheel chair which is provided with a remote stopping
means.
It is still another object of this invention to provide a motorized
wheel chair which is relatively inexpensive and is adaptable for
operation as a child grows.
Still other objects and advantages of this invention shall become
apparent from the ensuring descriptions of the invention.
A motorized wheel chair is provided comprising a chassis having two
rear wheels and one front wheel mounted thereon. The front wheel is
steerable by a handlebar. The rear wheels are driven by an electric
motor, coupled to a gearbox, for reducing the speed of the wheel
chair. The gearbox drives a friction drive assembly which is
engageable with the rear wheels and also is coupled to the
handlebar such that one of the rear wheels will be disengaged
depending upon which direction the handlebar is turned. The device
is provided with a switch which cuts power to the device when a
change in surface elevation of a desired amount is detected either
in front of or behind the device. A second switch may be provided
to stop the vehicle upon contact with another object. A third
switch may be activated remotely to stop the device. Also, the
chassis is adjustable in length, such that as a child grows the
device may be adjusted accordingly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a preferred embodiment of the
invention.
FIG. 2 is a top view of a preferred embodiment of the invention
with the outer coverings and right rear wheel removed.
FIG. 3 is a side view of a preferred embodiment of the invention
with the outer coverings removed.
FIG. 4 is a rear view of a preferred embodiment of the invention
with the outer coverings removed.
FIG. 5 is a front view of a preferred embodiment of the front
steering mechanism of the invention.
FIG. 6 is a side view of the front steering mechanism of the
invention as it is attached to the chassis of the invention.
FIG. 7 is a top view of the adjustable chassis of a preferred
embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
As shown in FIGS. 1 and 2, the vehicle 1 generally comprises a
chassis 2, on which are mounted a front wheel 3, a right rear wheel
4 and a left rear wheel 5. As can be seen, the wheels 3, 4 and 5
are located within the outer perimeter of the vehicle. This
arrangement complements the sensory equipment on the vehicle, which
will be described in further detail herein, and reduces the
likelihood of wheel contact with foreign objects. The vehicle 1 can
be steered by a steering means 6, which is usually a handlebar, as
shown in the Figures. The handlebar 6 is provided with a handlebar
post 23, which passes through a front bearing assembly 24 in
chassis 2 and connects to front forks 25. In a preferred
embodiment, handlebar post 23 is removable and replaceable with an
eating tray, learning aids, a desk top or other such items. A
throttle 7 is provided for speed control. The throttle 7 may assume
various forms known in the art. In the Figures, the throttle 7 is
shown in the form of a twist grip. A shift lever 8 is provided to
enable the operator to shift between forward and reverse. Sterring
means 6, throttle 7 and shift lever 8 could be combined
electronically into a joy stick control such that all vehicle
movements could be controlled by a single component, actuated by a
single hand or head movement by the operator. A front covering 9
and a rear covering 10 encase the internal workings of the vehicle.
It is preferable that coverings 9 and 10 be lockable to prevent
tampering and promote safety. A seat 11 is provided for the
operator. In order to assure a tight turning radius, it is
preferred that rear wheels 4 and 5 be located generally beneath the
seat 11. Safety belts 12 may be provided to hold the operator in
place. A front bumper 13 and a rear bumper 14 are provided to
encase the perimeter of front covering 9 and rear covering 10,
respectively. The bumpers 13 and 14 will also serve complement the
sensory equipment on the vehicle 1.
One separate requirement for the vehicle 1 is that it must travel
at a slow rate to permit proper supervision of the child and to
prevent accidents.
The vehicle is powered by an electric motor 15. Electrical wiring
has been omitted for clarity. It will be understood that shift
lever 8, throttle 7, motor 15, front elevation sensing means 52,
rear elevation sensing means 53, remote switching means 55 front
object detection means 56, rear object detection means 57 and
battery system 58 are connected to circuit box 54 by means known in
the art so as to perform their respective functions. In order to
provide the reduction in speed, various means may be employed. As
shown in FIGS. 2-4, a small pulley 16, rotatably connected to motor
15, drives a large pulley 17 which is connected to a gear reduction
means 18, usually a gearbox. The pulleys are driven by means of a
belt 19. The gearbox 18 drives drive shaft 20 at a greatly reduced
rate of rotation compared to that of small pulley 16.
Connected to either end of drive shaft 20 are a right friction
drive roller 21 and a left friction drive roller 22. When turning,
rollers 21 and 22 maintain contact with rear wheels 4 and 5,
respectively, and the vehicle 1 moves accordingly. One problem
which arises concerning three-wheeled vehicles is that of the
vehicle's ability to turn. When the front wheel 3 is turned and
both rear wheels 4 and 5 are driving, the vehicle tends to move
forward rather than to run in the direction urged by the front
wheel 3. This situation is compounded by the increased driving
power resulting from the gear reduction means 18 described above.
Applicant has solved this problem by employing a unique, but
simple, steering arrangement. As shown in FIGS. 5 and 6, a collar
26 is attached to handlebar post 23. A right steering cable 27 and
a left steering cable 28 are fixedly connected to collar 26 at
right and left cable clamps, 29 and 30, respectively. Right and
left cable clamping screws 43 and 44 hold cables 27 and 28 in place
in collar 26. Steering cables 27 and 28 are encased so as to allow
relative movement between cable casings 31 and cables 27 and 28.
Front bracket 32 serves to hold cable casings 31 in a stationary
position to allow for relative movement. Thus, as the handlebar
post 23 is turned, steering cables 27 and 28 will move
accordingly.
Right and left steering cables 27 and 28 are connected to right and
left clutch assemblies, 33 and 34, respectively. The right clutch
assembly 33 comprises a right clutch bracket 35, a right clutch pin
36, a right clutch lever 37 and a right drive bearing 38. The left
clutch assembly 34 similarly comprises a left clutch bracket 39, a
left clutch pin 40, a left clutch lever 41 and a left drive bearing
41. The gearbox 18 is mounted on a pad 45 of resilient material,
which is in turn mounted to the chassis 2, such that the gearbox
18, drive shaft 20 and friction drive rollers 21 and 22 are allowed
to twist slightly as a unit upon the application of torque. When
torque is released, the unit will return to its normal position. In
normal position, right and left friction drive rollers 21 and 22
are held in contact with right and left rear wheels 4 and 5,
respectively, by right drive spring 46 and left drive spring 47.
Thus, should the operator desire to make a right turn, the
handlebar 6 is turned clockwise, placing tension on the right
steering cable 27, activating the right clutch lever 37, which
urges the right drive bearing 38 and thus the right friction drive
roller 21 away from the right rear wheel 4, causing the vehicle 1
to execute a right turn as the left rear wheel 5 continues to turn.
When the handlebar 6 is straightened drive springs 46 and 47 urge
both friction drive rollers 21 and 22 back into contact with rear
wheels 4 and 5. The clutch assemblies 33 and 34 also allow for
single motor operation, saving on costs, electrical circuitry and
battery drain. Of course, separate motors 15 (with necessary gear
reduction means 18) could be provided for each rear wheel 4 and 5.
In this instance, turning could be controlled electronically by a
joy stick control as described previously.
Of course, steering means 6 and clutch assemblies 33 and 34 may
take various forms known in the art. For example, steering means 6
could comprise a joy stick type control for use by operators with
limited hand movement. Such a control could also incorporate
throttle 7 if necessary.
In order to lower the center of gravity of the vehicle 1, the rear
axle 48 is elevated above the chassis 2 by means of right and left
axle support brackets 49 and 50. This arrangement allows for
increased stability of the vehicle 1. In order to provide increased
assurance of stability, at least one rear caster 51 may be provided
to prevent the possibility of the vehicle 1 rearing up upon rapid
acceleration.
The vehicle 1 is provided with a front elevation sensing means 52
and a rear elevation sensing means 53, for sensing abrupt changes
in surface elevation, such as steep drop-offs or steps. Range
finding sonar circuits, of the type used in camera equipment, have
proven successful for this application. Both elevation sensing
means 52 and 53 are connected to circuit box 54 such that when a
desired elevation difference is detected, power to the motor 15 is
interrupted and the vehicle is stopped, until the vehicle 1 is
removed from the danger area by a parent or other supervisory
adult.
A remote switching means 55 is also provided to further enhance the
safety features of the vehicle 1. Upon receipt of a given signal,
the remote switching means 55 may be utilized to interrupt or
reinstate power to the vehicle 1. A whistle-activated switch, such
as that manufactured by Radio Shack, Catalog Number 277-1011 may be
utilized for this purpose. Thus, if the vehicle 1 is seen moving
toward a dangerous or undesired location, a parent need only blow a
whistle to stop the vehicle 1. A second blast from a whistle is
necessary to reinstate power to the vehicle 1. Of course, other
types of remote switching apparatus may also be used.
Because of the low speed and high gear ratio of the vehicle 1, it
tends to be unusually powerful. Therefore, in order to protect
furniture and other fixtures as well as to provide increased
safety, the vehicle 1 is provided with front and rear object
detection means 56 and 57 which sense contact between the vehicle's
front and rear bumpers 13 and 14, respectively, and foreign
objects. The object detection means 56 and 57 are connected to the
vehicle circuit box 54 such that upon contact with a foreign
object, power will be interrupted and the vehicle will be stopped.
In a preferred embodiment, front object detection means 56 is
connected such that, when activated, the motor 15 will not operate
in a forward direction. Likewise, the rear object detection means
57 is connected so as, when activated, to prevent operation in a
reverse direction. Thus, the operator is able to extricate himself
from difficulty without assistance under certain conditions.
Front and rear object detection means 56 and 57 may comprise
various types of sensing devices. In one embodiment, shown in the
Figures, front and rear bumpers 13 and 14 comprise inflated rubber
tubing. Front and rear object detection means 56 and 57 comprise
pressure sensitive switches, connected to bumpers 13 and 14. The
switches 56 and 57 are responsive to the pressure increase caused
by bumper contact with a foreign object. Of course, front and rear
object detection means 56 and 57 could take other forms. For
example, bumpers 13 and 14 could each contain a pair of
electrically conductive strips which would normally be spaced
apart, but would contact each other, closing a circuit, when in
contact with a foreign object.
The vehicle 1 is powered by battery system 58. It is preferred that
the battery system 58 includes a pair of six volts gel cell
batteries. The gel cell batteries eliminate the danger of acid
spills. This arrangement allows for one battery to be utilized for
electronics circuitry, eliminating the need for a voltage regulator
or voltage drop circuit. Both batteries would operate the twelve
volt motor 15. Preferably, a one amp battery charger 59 is provided
for overnight charging.
The chassis 3 may be divided into a front section 60 and a rear
section 61, as shown in FIG. 7. The front chassis section 60 is
provided with a tongue 62, which has adjustment holes 63. Any two
adjustment holes 63 may thus be aligned with mounting holes 64 in
rear chassis section 61 and then bolted together to form a unitary
chassis 2 which is adjustable in length. The chassis 2 is thereby
made expandable such that, as a child grows, he does not outgrow
the vehicle 1.
As can be seen, a motorized wheel chair is provided which enables
physically or mentally challenged small children to safely and
efficiently move about with a minimum of adult supervision. There
are, of course, many alternate embodiments intended to be within
the spirit and scope of this invention, as defined by the following
claims.
* * * * *