Wheel chair abstract
A power driven wheel chair is described which includes a rear wheel
support frame and at least two ground engaging rear wheels mounted
in spaced relation to opposed sides of the rear wheel support frame.
A front wheel support frame is pivotally secured to the rear wheel
support frame for pivotal movement about a substantially horizontal
axis. At least two ground engaging front wheels are mounted in spaced
relation to opposed sides of the front wheel support frame. A drive
motor provides motive force to at least one wheel of one of the
pairs of at least two ground engaging wheels. A chair is mounted
on one of the rear wheel support frame and the front wheel support
frame. The wheel chair, as described, has added stability as relative
pivoting of the rear wheel support frame and the front wheel support
frame maintains the wheels in contact the ground at all times.
Wheel chair claims
The embodiments of the invention in which an exclusive property
or privilege is claimed are as follows:
1. A power driven wheel chair, comprising:
a. a rear wheel support frame;
b. at east two ground engaging rear wheels mounted in spaced relation
to opposed sides of the rear wheel support frame;
c. a front wheel support frame secured to the rear wheel support
frame;
d. at least two ground engaging front wheels mounted in spaced
relation to opposed sides of the front wheel support frame;
e. a drive motor for providing motive force to at least one wheel
of one of the ground engaging rear wheels and the ground engaging
front wheels;
f. a chair having a back portion and a seat portion mounted on
one of the rear wheel support frame and the front wheel support
frame; and
g. a crane secured to the back portion of the chair, whereby a
person is lifted on to and off of the seat potion of the chair,
the crane having a mounting assembly pivotable about an axis substantially
perpendicular to the back portion of the chair, such that the crane
is pivotable between an operative position with a boom of the crane
positioned above the seat portion of the chair and a stored position
with the boom of the crane positioned adjacent to the seat of the
chair.
2. The power driven wheel chair as defined in claim 1, wherein
the front wheel support frame is pivotally secured to the rear wheel
support frame for pivotal movement about a substantially horizontal
axis and each ground engaging wheel is mounted by means of a walking
beam which includes a ground engaging companion wheel.
3. The power driven wheel chair as defined in claim 1, wherein
each ground engaging wheel is driven by motive force supplied by
the drive motor.
4. The power driven wheel chair as defined in claim 1, wherein
the chair is mounted on the rear wheel support frame by means of
a telescopic member, such that the telescopic member expands and
contracts to maintain the chair in a substantially horizontal orientation
regardless of the relative orientation of the rear wheel support
frame.
5. The power driven chair as defined in claim 2, wherein a castor
wheel is mounted by means of a telescopic member to the rear wheel
support frame, such that in an extended position the telescopic
member lifts the rear ground engaging wheels off a ground surface,
a cable extending from the telescopic member to the walking beam
of the front wheel support frame, such that as the telescopic member
is telescopically extended the cable exerts a force upon the walking
beam of the front wheel support frame to raise the ground engaging
companion wheel off the ground surface.
6. The power driven wheel chair as defined in claim 1, wherein
telescopically extendible stabilizing legs depend from the front
wheel support frame.
7. A power driven wheel chair, comprising:
a. a rear wheel support frame;
b. walking beams pivotally mounted in spaced relation to opposed
sides of the rear wheel support frame, each walking beam including
a ground engaging wheel and a ground engaging companion wheel;
c. a front wheel support frame pivotally secured to the rear wheel
support frame for pivotally movement about a substantially horizontal
axis;
d. walking beams pivotally mounted in spaced relation to opposed
sides of the front wheel support frame, each walking beam including
a ground engaging wheel and a ground engaging companion wheel;
e. a drive motor for providing motive force to each ground engaging
wheel and ground engaging companion wheel;
f. a chair having a back portion and a seat potion mounted on the
rear wheel support frame by means of a telescopic member, such that
the telescopic member expands and contracts to maintain the chair
in a substantially horizontal orientation regardless of the relative
orientation of the rear wheel support frame; and
g. a crane secured to the back portion of the chair, whereby a
person is lifted on to and off of the seat portion of the chair,
the crane having a mounting assembly pivotable about an axis substantially
perpendicular to the back portion of the chair, such that the crane
is pivotable between an operative position with a boom of the crane
positioned above the seat portion of the chair and a stored position
with the boom of the crane positioned adjacent to the seat of the
chair.
8. The power driven wheel chair as defined in claim 7, wherein
a castor wheel is mounted by means of a telescopic member to the
rear wheel support frame, such that in an extended position the
telescopic member lifts the rear ground engaging wheels off a ground
surface, a cable extending from the telescopic member to the walking
beam of the front wheel support frame, such that as the telescopic
member is telescopically extended the cable exerts a force upon
the walking beam of the front wheel support frame to raise the ground
engaging companion wheel off the ground surface.
9. The power driven wheel chair as defined in claim 7, wherein
telescopically extendible stabilizing legs depend from the front
wheel support frame.
10. A power driven wheel chair, comprising:
a. a rear wheel support frame;
b. walking beams pivotally mounted in spaced relation to opposed
sides of the rear wheel support frame, each walking beam including
a ground engaging wheel and a round engaging companion wheel;
c. a front wheel support frame pivotally secured to the rear wheel
support frame for pivotal movement about a substantially horizontal
axis;
d. walking beams pivotally mounted in spaced relation to opposed
sides of the front wheel support frame, each walking beam including
a ground engaging wheel and a ground engaging companion wheel;
e. a drive motor for providing motive force to each ground engaging
wheel and ground engaging companion wheel;
f. a chair having a back potion and a seat potion mounted one the
rear wheel support frame by means of a telescopic member, such that
the telescopic member expands and contracts to maintain the chair
in a substantially horizontal orientation regardless of the relative
orientation of the rear wheel support frame;
g. a castor wheel mounted of a telescopic member to the rear wheel
support frame, such that in an extended position the telescopic
member lifts the rear ground engaging wheels off a ground surface,
a cable extending from the telescopic member to the walking beam
of the front wheel support frame, such that as the telescopic member
is telescopically extended the cable exerts a force upon the walking
beam of the front wheel support frame to raise the ground engaging
companion wheel off the ground surface;
h. a crane secured to the back portion of the chair, whereby a
person is lifted on to and off of the seat portion of the chair,
the crane having a mounting assembly pivotable about an axis substantially
perpendicular to the back portion of the chair, such that the crane
is pivotable between an operative position with a boom of the crane
positioned above the seat portion of the chair and a stored with
the boom of the crane positioned adjacent to the seat of the chair;
and
i. telescopically extendible stabilizing legs depending from the
front wheel support frame.
Wheel chair description
The present invention relates to a power driven wheel chair.
BACKGROUND OF THE INVENTION
Power driven wheel chairs enable persons who must use such conveyances
greater freedom of movement. This is particularly apparent in relation
to use out of doors. Power driven wheel chairs can go across uneven
terrain that a hand propelled wheel chair could not possibly manage.
It is difficult for a power driven wheel chair to maintain all
its wheels on the ground when stepping over obstacles. When one
of the front wheels of a wheel chair climbs an obstacle, it tends
to lift the rear wheel on the same side. When one of the front wheels
of a wheel chair descends an obstacle, it tends to lift the rear
wheel on the opposite side. These tendencies adversely effect the
traction of the rear wheels, and the overall stability of the wheel
chair.
SUMMARY OF THE INVENTION
What is required is a power driven wheel chair that is more stable
when travelling over uneven terrain.
According to the present invention there is provided a power driven
wheel chair which includes a rear wheel support frame and at least
two ground engaging rear wheels mounted in spaced relation to opposed
sides of the rear wheel support frame. A front wheel support frame
is pivotally secured to the rear wheel support frame for pivotal
movement about a substantially horizontal axis. At least two ground
engaging front wheels are mounted in spaced relation to opposed
sides of the front wheel support frame. A drive motor provides motive
force to at least one wheel of one of the pairs of at least two
ground engaging wheels. A chair is mounted on one of the rear wheel
support frame and the front wheel support frame.
The wheel chair, as described above, has added stability as relative
pivoting of the rear wheel support frame and the front wheel support
frame maintains the wheels in contact the ground at all times. Although
beneficial results may be obtained through the use of the power
driven wheel chair, as defined above, there are further enhancements
that can further improve the ability of the wheel chair to climb
stairs. Even more beneficial results may, therefore, be obtained
when each ground engaging wheel is mounted by means of a walking
beam which includes a ground engaging companion wheel. It is preferred
that each ground engaging wheel is driven by motive force supplied
by the drive motor.
Although beneficial results may be obtained through the use of
the power driven wheel chair, as defined above, a person riding
in the wheel chair will not feel secure when positioned at an odd
angle, and the wheel chair may tip if the center of gravity is not
correctly positioned. Even more beneficial results may, therefore,
be obtained when the chair is mounted on the support frame by means
of a telescopic member. The telescopic member can expand and contract
to maintain the chair in a substantially horizontal orientation
regardless of the relative orientation of the support frame. The
person riding in the wheel chair feels more secure when maintained
in a horizontal position. This also performs the very important
function of adjusting the center of gravity so the wheel chair is
less prone to tipping. The telescopic mounting can also be used
to raise the chair for other purposes, such as reaching high shelves.
Although beneficial results may be obtained through the use of
the power driven wheel chair, as described above, if the wheel chair
is to be suitable for indoor use it must be capable of making short
radius turns. Even more beneficial results may, therefore, be obtained
when a castor wheel is mounted by means of a telescopic member to
one of the rear wheel support frame and the front wheel support
frame. In an extended position the telescopic member lifts the ground
engaging wheels off a ground surface thereby enabling the castor
wheel supports the weight of the rear wheel support frame during
short radius turns. This ability to make short radiused turns is
further enhanced when means is provided for raising at least one
of the ground engaging wheels mounted by means of the walking beam.
Although beneficial results may be obtained through the use of
the power driven wheel chair, as described above, it is difficult
for a person to get from the wheel chair into a bath tub without
assistance. Any place where the person cannot use his arms to slide
directly across can present a problem. Even more beneficial results
may, therefore, be obtained when the chair has a back, and a crane
is secured to the back of the chair, whereby a person is lifted
on to and off of the chair. It is preferred that telescopically
extendible stabilizing legs depend from the front wheel support
frame. The stabilizing legs prevents the wheel chair from becoming
overbalanced when the crane is under load. It is also preferred
that the crane has a mounting assembly pivotable about an axis substantially
perpendicular to the back portion of the chair. This enables the
crane to pivot between an operative position with a boom of the
crane positioned above a seat portion of the chair and a stored
position with the boom of the crane positioned adjacent to the seat
of the chair.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent
from the following description in which reference is made to the
appended drawings, wherein:
FIG. 1 is a side elevation view of a wheel chair constructed in
accordance with the teachings of the present invention.
FIG. 2 is a side elevation view of the wheel chair illustrated
in FIG. 1, with wheel mountings superimposed.
FIG. 2a is a side elevation view of the wheel chair illustrated
in FIG. 1, with the crane in an operative position.
FIG. 3 is a side elevation view of the wheel chair illustrated
in FIG. 1, with the crane in a stored position.
FIG. 4 is a side elevation view in longitudinal section of the
wheel chair illustrated in FIG. 2.
FIG. 5 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the first of five drawings showing the manner
in which the wheel chair maneuvers over uneven terrain.
FIG. 6 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the second of five drawings showing the manner
in which the wheel chair maneuvers over uneven terrain.
FIG. 7 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the third of five drawings showing the manner
in which the wheel chair maneuvers over uneven terrain.
FIG. 8 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the fourth of five drawings showing the manner
in which the wheel chair maneuvers over uneven terrain.
FIG. 9 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the fifth of five drawings showing the manner
in which the wheel chair maneuvers over uneven terrain.
FIG. 10 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the first of three drawings showing the manner
in which the orientation of the chair is telescopically adjustable.
FIG. 11 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the second of three drawings showing the manner
in which the orientation of the chair is telescopically adjustable.
FIG. 12 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the third of three drawings showing the manner
in which the orientation of the chair is telescopically adjustable.
FIG. 13 is a side elevation view of the wheel chair illustrated
in FIG. 2, shouting the manner in which short radius turns are executed.
FIG. 14 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the first of four drawings showing the manner
in which stairs are negotiated.
FIG. 15 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the second of four drawings showing the manner
in which stairs are negotiated.
FIG. 16 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the third of four drawings showing the manner
in which stairs are negotiated.
FIG. 17 is a side elevation view of the wheel chair illustrated
in FIG. 2, and is the fourth of four drawings showing the manner
in which stairs are negotiated.
FIG. 18 is a front elevation view of the wheel chair illustrated
in FIG. 2, and is the first of two drawings showing the manner in
which obstacles are climbed.
FIG. 19 is a front elevation view of the wheel chair illustrated
in FIG. 2, and is the second of two drawings showing the manner
in which obstacles are climbed.
FIG. 20 is a rear perspective view of a frame from the wheel chair
illustrated in FIG. 2.
FIG. 21 is a top plan view in section of the wheel chair illustrated
in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment, a power driven wheel chair generally
identified by reference numeral 30, will now be described with reference
to FIGS. 1 through 21.
Power driven wheel chair 30 is illustrated in FIG. 1. Referring
to FIGS. 18 through 20, power driven wheel chair 10 includes a rear
wheel support frame 32 and a front wheel support frame 34. Front
wheel support frame 34 is pivotally secured to rear wheel support
frame 32 for pivotal movement about a substantially horizontal axis,
designated by reference numeral 36. Referring to FIG. 20, walking
beams 38 are pivotally mounted in spaced relation to opposed sides
40 and 42 of rear wheel support frame 32. Each walking beam 38 includes
a ground engaging wheel 44 and a ground engaging companion wheel
46. Similarly, walking beams 48 are pivotally mounted in spaced
relation to opposed sides 50 and 52 of front wheel support frame
34. Each walking beam 48 includes a ground engaging wheel 54 and
a ground engaging companion wheel 56. A cable is secured to walking
beam 48 adjacent companion wheel 56. Cable 58 enables walking beam
48 to be selectively pivotable to raise ground engaging companion
wheel 56 in the fashion illustrated in FIG. 13, as will hereinafter
be further described. Rear wheel support frame 32 and front wheel
support frame 34 are interchangeable. In the illustrated embodiment
the shorter of the two frame sections has been designated as front
wheel support frame 34. The designation of the ground engaging wheels
as "companion" wheels relates to their connection to the
drive system which will hereinafter be further explained. Referring
to FIG. 21, two drive motors 60 and 61 provides the motive force
to each ground engaging wheel 44 and 54 and each ground engaging
companion wheel 46 and 56. The manner of connection is illustrated
in FIGS. 4 and 21. Drive motor 60 provides the motive force for
the operation of ground engaging wheels along sides 40 and 50 of
support frames 32 and 34, respectively. Drive motor 61 provides
the motive force for the operation of ground engaging wheels along
sides 42 and 52 of support frames 32 and 34, respectively. A drive
sprocket assembly 62 is positioned between each ground engaging
wheel and its companion wheel. An output shaft 66 of each drive
motor 60 and 61 is linked by drive chains 64 and 68 to each drive
sprocket assembly 62. When either drive motor 60 or 61 is in operation,
drive sprocket assemblies 62 are rotated via drive chains 64 and
68. Companion wheels 46 and 56 are rotatably linked by secondary
drive chains 70 to ground engaging wheels 44 and 54, respectively.
Drive sprocket assemblies 62 engage chains 70 to rotate ground ,engaging
wheels 44 and 54 and companion wheels 46 and 56 together. Referring
to FIG. 12, a chair 72 having a back portion 74 and a seat portion
76 is mounted on rear wheel support frame 32 by means of two telescopic
members 78 and 80. Telescopic members 78 and 80 are hydraulic cylinders
that .expand and contract to maintain chair 72 in a substantially
horizontal orientation regardless of the relative orientation of
rear wheel support frame 32. Referring to FIG. 13, a castor wheel
82 is mounted by means of a telescopic member 84 to rear wheel support
frame 32. Telescopic member 84 is an hydraulic cylinder which, in
an extended position, lifts ground engaging wheels 44 and 46 off
a ground surface 86 thereby enabling castor wheel 82 supports the
weight of the rear wheel support frame during short radius turns.
It should be noted that telescopic member 84 is linked by cable
58 to walking beam 48. Referring to FIGS. 2, 2a and 3, a crane 88
is secured to back portion 74 of chair 72. Persons can be lifted
on to and off of seat portion 76 of chair 72 with crane 88. As is
apparent from a comparison of FIGS. 2 and 3, crane 88 has a mounting
assembly 90 pivotable about an axis, designated by reference numeral
92, which is substantially perpendicular to back portion 74 of chair
72. This enables crane 88 to be pivoted between an operative position,
illustrated in FIG. 2, with a boom 94 of crane 88 positioned above
seat portion 76 of chair 72 and a stored position, illustrated in
FIG. 3, with boom 94 of crane 88 positioned adjacent to seat portion
76 of chair 72. Referring to FIG. 2a , telescopically extendible
stabilizing legs 96 depend from front wheel support frame 32. Referring
to FIG. 1, controls 98 which control the operation of the various
features of power driven wheel chair 10 are mounted onto an arm
rest 100 extending from back portion 74 of chair 72. Associated
with crane 88 are a sling support 102 which is suspended by a cable
104 from boom 94. The length of cable 104 is controlled by rotation
of a motor driven feed spool 106. Crane 88 articulates about a substantially
horizontal axis, identified by reference numeral 108.
The use and operation of motor driven wheel chair 10 will now be
described with reference to FIGS. 1 through 21. Crane 88 is used
to lift persons on to and off of seat portion 76 of chair 72. Stabilizing
legs 96 are telescopically extended in the manner illustrated in
FIG. 2a to provide power driven wheel chair 10 with stability while
lifting. Sling support 102 is placed around the torso of the person
being lifted. The lifting force is applied by controlling the length
of cable 104 from which sling support 102 is suspended. This is
done by motor driven feed spool 106. Boom portion 94 of crane 88
is swung laterally as required about horizontal axis 108. When crane
88 is not required it is pivoted about pivot axis 92 into the stored
position illustrated in FIG. 3. Referring to FIGS. 5 through 9,
walking beams 38 and 48 assist in maintaining the ground engaging
wheels in contact with ground surface 86 when travelling over rough
terrain by pivoting to conform to the slope. Referring to FIGS.
10 and 11, telescopic members 78 and 80 expand and contract to maintain
chair 72 in a substantially horizontal orientation regardless of
the relative orientation of rear wheel support frame 32. Referring
to FIG. 12, telescopic members 78 and 80 can both be expanded at
the same time to lift the chair 72 to permit the person seated in
chair 72 to reach high objects. Referring to FIG. 13, when a short
radius turn is desired, telescopic member 84 is used to drop castor
wheel 82. As telescopic member 84 extends cable 58 serves to pivot
walking beam 48, lifting companion ground engaging wheel 56 off
ground surface 86. Once telescopic member 84 is in a fully extended
position, ground engaging wheels 44 and 46 are lifted off of ground
surface 86 and castor wheel 82 supports the weight of the rear wheel
support frame during short radius turns as ground engaging wheels
54 are rotated. This is accomplished by activating drive motor 60
to turn the ground engaging wheels on side 40 and 50 in one direction,
while activating drive motor 61 to turn the ground engaging wheels
on side 42 and 52 in the opposite direction. Referring to FIGS.
14 through 17, the manner in which power driven wheel chair 10 climbs
stairs is illustrated. The manner in which walking beams 38 and
48 pivot is to be noted. This maintains wheels in contact with the
stairs. Ground engaging wheels 44 and 54 and companion ground engaging
wheels 46 and 56 assist each other with the climb. Referring to
FIGS. 18 and 19, the manner in which front wheel support frame 34
pivots relative to rear wheel support frame 32 is illustrated. It
is to be noted that the front wheels can climb or descend an obstacle
without lifting the rear wheels off of ground surface 86.
It will be apparent to one skilled in the art the increased stability
that power driven wheel chair 10 provides when performing various
tasks. It will also be apparent to one skilled in the art that power
driven wheel chair 10 performs a wide range of tasks that prior
to its development could only be performed by having more than one
wheel chair, as no one wheel chair could perform all the tasks illustrated.
It will finally be apparent to one skilled in the art that modifications
may be made to the illustrated embodiment without departing from
the spirit and scope of the invention as defined by the Claims.
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