Wheel chair abstract
A wheel chair drive apparatus includes a frame having a wheel mount,
a battery mount, and a control shaft mount. A drive wheel has a
drive motor incorporated within the drive wheel. A battery is in
operative communication with the drive motor via a detachable jack.
A battery housing is dimensioned to mount in the battery mount of
the frame and has a handle. A control shaft pivotably mounted on
the control shaft mount, so that it has a stow position, and operating
position, a user entry position and a table use position. A caster
lever is pivotably mounted to the frame, so that it has a rolling
position and an engaged position. The caster lever is disposed to
engage a receiving seat on a wheel chair. A locking lever is releasably
biased toward a position locking the caster lever in the engaged
position.
Wheel chair claims
What at is claimed is:
1. A wheel chair drive apparatus comprising: a frame having a wheel
mount, a battery mount, and a control shaft mount; a drive wheel
having an axle; a drive motor incorporated within said drive wheel;
a battery in operative communication with said drive motor via a
detachable jack; a battery housing dimensioned to mount in said
battery mount of said frame, said battery housing having a handle;
a control shaft pivotably mounted on said control shaft mount, said
control shaft having at least a stow position, and operating position,
a user entry position and a table use position; a caster lever pivotably
mounted to said frame, said caster lever having at least a rolling
position and an engaged position, said caster lever being disposed
to engage a receiving seat on a wheel chair; and a locking lever
releasably biased toward the position locking said caster lever
in said engaged position.
2. The wheel chair drive apparatus of claim 1 wherein said drive
motor is coaxial with said drive wheel.
3. The wheel chair drive apparatus of claim 1 wherein said drive
motor has a stator fixed to said axle.
4. The wheel chair drive apparatus of claim 1 wherein a said drive
wheel has a circumferential ground contact surface is integrally
formed with a rotor of said drive motor.
5. The wheel chair drive apparatus of claim 4 further comprising
a tread attached to said circumferential ground contact surface.
6. The wheel chair drive apparatus of claim 1 wherein said drive
motor has a torque at least about ______.
7. The wheel chair drive apparatus of claim wherein said drive
motor has an efficiency of at least about 75%.
8. The wheel chair drive apparatus of claim 1 wherein said control
shaft is continuously selectively positionable on said control shaft
mount.
9. The wheel chair drive apparatus of claim 1 wherein said control
shaft is mounted on said control shaft mount with a combination
of bosses and detents for selectively positioning said control shaft
among a plurality of positions.
10. The wheel chair drive apparatus of claim 9 wherein said boss
is spring loaded and mounted on said control shaft such that spring
may be manually moved from a rest position for disengaging said
boss from a selected detent and said spring may be manually released
for reengaging said boss with another selected detent.
11. The wheel chair drive apparatus of claim 1 wherein said control
shaft has a throttle mounted near its upper aspect.
12. The wheel chair drive apparatus of claim 1 wherein said control
shaft has a display mounted near its upper aspect.
13. The wheel chair drive apparatus of claim 12 wherein said display
includes a LED.
14. The wheel chair drive apparatus of claim 12 wherein said display
indicates a charge level of said battery.
15. The wheel chair drive apparatus of claim 1 wherein said battery
is sealed within said battery housing.
16. The wheel chair drive apparatus of claim 1 wherein said battery
and said battery housing together weigh less than about 30 pounds.
17. The wheel chair drive apparatus of claim 1 wherein said handle
is dimensioned to raise front portion of a frame of a standard wheel
chair when said wheel chair drive apparatus is engaged with said
wheel chair.
18. The wheel chair drive apparatus of claim 17 wherein said raised
position of said wheel chair maintains a front caster wheel of the
wheel chair elevated above the ground.
19. The wheel chair drive apparatus of claim 1 wherein said handle
of said battery housing is peaked along its length.
20. The wheel chair drive apparatus of claim 19 wherein said peak
is dimensioned to correspond to an X frame of a standard of wheel
chair.
21. The wheel chair drive apparatus of claim 1 wherein said handle
of said battery housing is made at least in part of delrin.
22. The wheel chair drive apparatus of claim 1 wherein said receiving
seat is fabricated into a caster lever mount.
23. The wheel chair drive apparatus of claim 22 wherein said caster
lever mount is a separate component, and said caster lever mount
is adapted for attachment to a standard wheel chair.
24. The wheel chair drive apparatus of claim 22 wherein said caster
lever mounts are two in number.
25. The wheel chair drive apparatus of claim 22 wherein said caster
lever mounts have guide wings.
26. The wheel chair drive apparatus of claim 22 wherein said caster
lever mounts have an engaging stop face.
27. The wheel chair drive apparatus of claim 22 wherein said caster
lever mounts incorporate a receiving seat dimensioned to closely
cooperate with a horizontal bar, said horizontal bar being a component
of said caster lever.
Wheel chair description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] None.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
APPENDIX
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention is in the field of motorized wheel
chairs, particularly, separable apparatuses attachable to standard
wheel chairs to provide power to drive them.
[0006] 2. Related Art
[0007] Substantial obstacles to mobility and everyday tasks of
living continue for those disabled and bound to wheel chairs. There
is a continuing need to make mobility for the wheel chair bound
more reliable and convenient.
[0008] Motor drives for standard wheel chairs exist in the prior
art. U.S. Pat. No. 5,494,126 to Meeker and U.S. Pat. No. 5,050,695
to Kleinwolterink Jr. describe motor drive units that may be attached
to standard push wheel chairs.
[0009] U.S. Pat. No. 5,050,695 describes a geared brush type DC
motor chain coupled to a very small drive wheel. It makes use of
a fixed steering column. Only the height of the column can be adjusted
to fit individual needs, by loosening a setscrew. The drive wheel
is coupled to a frame though a bearing journal. The frame forms
a well into which two large batteries are supported. Power is applied
to the motor through a cable and is controlled with the control
box at the top of the steering column. The speed and direction of
the motor is accomplished through wings attached to the control
box. The wings are attached to simple switches inside the control
box. The patent further describes pivotal frames attached to the
rear section of the wheel chair frame. Attached to the pivotal frames
are sockets into which an inverted U-shaped crossbar is inserted.
When the unit is connected to the wheel chair, two hooks on the
rear of the frame hook onto the U-shaped crossbar, which lifts the
rear of the frame. Two rails on each side of the frame come in contact
with the X-frame of the wheel chair and this lifts the front of
the wheel chair. This procedure locks the unit in place.
[0010] U.S. Pat. No. 5,494,126 describes an apparatus and method
for attaching a motorized wheel to a wheel chair. This unit is attached
to the front of the wheel chair through the use of two brackets
bolted to the front tubes of the wheel chair. The steering column
is telescopically connected to the drive wheel and held in place
with a collar and a setscrew. When connecting the drive unit to
the wheel chair the steering column is replaced with a temporary
installation handle. After the installation handle has been inserted
it is held in place with a collar and set screw. The unit is then
held in a partially upright position and two posts are guided into
the C shaped openings of the brackets on either side of the front
of the wheel chair. The occupant then presses forward on the installation
handle forcing the drive wheel back under the front of the wheel
chair. After the drive wheel is all the way under the front of the
wheel chair the operator must then hold it in place and slide two
pins into the brackets on either side of the wheel chair. These
locking pins are then held in place with locking screws. The operator
must then loosen the setscrews holding the installation handle in
place, remove the installation handle and then install the battery.
Next replace the steering column and lock the steering column in
place with a collar and setscrew. Two, wires with spade lugs must
then be connected to the battery with terminal screws. It is possible
to connect the wires backwards.
[0011] These devices are cumbersome in their operation, installation
and transportation. The units are heavy and do not disassemble or
collapse into a compact package. This creates difficulty in packing,
as for example in the trunk of an automobile. Weight represents
a substantial hardship, particularly for the elderly person, whose
caregiver is commonly an elderly spouse. Prior art devices are also
bulky and do not collapse into a small enough package for convenient
transportation, again as in the trunk of a car.
[0012] The prior art units do not have batteries that are easily
removable. Moreover, the batteries are not encased in a separate
housing. Accordingly, separate packaging of the batteries is required
to transport prior art batteries on public transportation such as
commercial airlines. There is no provision for re-charging the batteries.
[0013] The prior art devices have in common a vertical shaft for
holding a control module where the wheel chair occupant may reach
it. This shaft is not movable, and accordingly obstructs ingress
and egress from the wheel chair. The unadjustable vertical control
shaft makes simple tasks difficult, such as pulling the chair up
to the table, as for reading or a meal.
[0014] These units are also difficult to install for a caregiver.
They are prohibitively difficult for the disabled individual themselves
to install. This is due to the mounting apparatus, which cannot
automatically seat itself by simple engagement with the chair, which
has no alignment guides to ease installment and which also prevents
folding the chair up for storage when the apparatus is attached.
[0015] The prior art devices have inefficient drive trains that
use drive chains and further necessitate inefficient gearing and
small drive wheels. Their systems are only 35% efficient. This inefficiency
leads to a choice between either large, heavy batteries or smaller
batteries that use an inordinate amount of power with an appreciably
shorter charge life.
[0016] In operation, the prior art units use small drive wheels
that too readily transfer shock from minor impediments, such as
a brick floor. Even slightly larger objects, such as a cobble stone
street, become virtually impossible to traverse.
[0017] It is in view of the above referenced shortcomings that
the present invention was developed.
SUMMARY OF THE INVENTION
[0018] The invention is an improved drive device for attachment
to the standard wheel chair. The device is separable into two separate
components for transportation. One component is a battery, contained
in a separate, sealed housing. The battery and housing have a separate
handle and are dimensioned to be of a convenient size and weight.
The remaining second component includes a frame, high torque electric
motor, drive wheel, and collapsible control shaft.
[0019] This invention consists of a motorized wheel chair drive
unit providing steerable motive power, which can be easily attached
to or detached from a standard manual wheel chair and makes use
of a direct drive system. This drive requires no gear reducers and
no coupling mechanisms such as chains or belts. This drive system
is much more efficient than those used in prior art. The efficiency
is approximately 80% . This allows a choice between using a smaller
battery which travels the same time and distance as prior art, and
using a full-size battery which travels a much greater distance
without recharging. It is preferred to use a smaller battery, which
in this design is enclosed in a steel case.
[0020] The drive motor is inside the drive wheel in one embodiment.
In another, the wheel is the motor. It is an inverted rotor design
with a stationary stator at the center of the motor and the rotor
on the outside. The tire is molded directly on the outside of the
rotor.
[0021] The motor wheel has a relatively large diameter of eight
and half inches. This permits easy passage over fairly large obstructions
such as doorsills. The motor incorporates two large permanently
lubricated sealed ball bearings. The wiring passes out through the
center of one of the bearings, up under a protective cover to the
electronic control box located above the motor The unit overcomes
restrictions of prior art of approaching a desk, a table, a bathroom
sink, a water fountain and a myriad of other places by allowing
the steering column to be released and rotated back in the operator's
lap. From the locked upright position, the steering column can also
be folded forward down against the floor and then turned to the
side, providing complete open access for entering and leaving the
wheel chair. There is a release knob, located near the front edge
of the wheel chair seat, which provides easy access for moving the
steering column. When the release knob is pulled, the motor control
is automatically turned off. In order to allow this feature to be
effective the motor control head at the top of the steering column
must be very slim and small. With the unit disconnected from the
wheel chair and the battery pack removed, the steering column can
then be folded down over the top of the frame where it locks in
a centered position. This minimizes the space required for storing
the unit and also provides a handle for moving the folded unit.
[0022] The process of connecting and disconnecting the unit with
the wheel chair is quick and easy, requiring no tools, allowing
a handicapped person to fix the drive apparatus in place under the
wheel chair for use.
[0023] There are two lightweight brackets bolted to the inside
rear of the wheel chair frame with outward slanted guides. There
are engagement seats for the driver apparatus formed on the inner
surface of these brackets. A swing assembly or caster lever is hinged
at the rear of the drive apparatus' frame. It rotates out approximately
45.degree.. The swing assembly rotates over center and is held in
the out position by the weight of the battery, and supported by
two roller casters. The swing assembly supports a horizontal rectangular
bar, which is transverse to the wheel chair and extends almost the
full width of the inside of the wheel chair frame. The casters are
mounted near the outer end of this horizontal bar. Mounted to the
top of the battery handle is an inverted V delrin slide. To connect
the unit, the swing assembly must be in the out position, and the
steering column turned at 90.degree. (to act as a brake). The wheel
chair is moved over the drive unit, and as the horizontal bar comes
in contact with the slanted guides on the wheel chair brackets the
roller casters allow the unit to be guided laterally until the rectangular
bar is captured by the engagement seats on the wheel chair brackets.
As the wheel chair moves further forward, the swing assembly is
driven to an upright vertical position. It is held in this vertical
position by a releasable latch mechanism. As the swing assembly
is driven to the upright vertical position, the rear of the frame
is lifted which pushes the inverted V delrin slide against the bottom
of the X-frame of the wheel chair. This lifts the front of the wheel
chair and at the same time the roller casters are lifted off the
ground. With the front of the wheel chair lifted, needed weight
is added to the motor wheel providing better traction.
[0024] A second means of connecting the unit can be accomplished
by applying the brakes on the wheel chair. The drive apparatus can
then be backed under the wheel chair using the power of the drive
unit. This design results in a three-wheeled device with a very
short wheelbase. Since the front casters of the wheel chair are
only slightly lifted off the ground, they serve as outriggers and
prevent the unit from tipping.
[0025] Further features and advantages of the present invention,
as well as the structure and operation of various embodiments of
the present invention, are described in detail below with reference
to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings, which are incorporated in and
form a part of the specification, illustrate the embodiments of
the present invention and together with the description, serve to
explain the principles of the invention. In the drawings:
[0027] FIG. 1 is a left side view of the drive apparatus for a
wheel chair;
[0028] FIG. 2 is a front view of the drive apparatus for a wheel
chair
[0029] FIG. 3 is a right side view of the drive apparatus for a
wheel chair;
[0030] FIG. 4 is a top view;
[0031] FIG. 5 is a top view with the battery removed;
[0032] FIG. 6 is a side view with a cutaway depiction of the engagement
of the swing arm assembly with the wheel chair mounting brackets
in a first position;
[0033] FIG. 7 is a side view with a cutaway depiction of the engagement
of the swing arm assembly with the wheel chair mounting brackets
in a continuing position;
[0034] FIG. 8 is a side view with a cutaway depiction of the engagement
of the swing arm assembly with the wheel chair mounting brackets
in a final position;
[0035] FIG. 9 is a side view of the drive apparatus with the battery
removed and the control shaft collapsed for storage;
[0036] FIG. 10 is a top view of the drive apparatus with the battery
removed and the control shaft collapsed for storage;
[0037] FIG. 11 is a right side view of the drive apparatus with
the battery removed and the control shaft collapsed for storage;
[0038] FIG. 12 is a close up of the control module;
[0039] FIG. 13 is a right sided view with the controls shaft in
a user access position;
[0040] FIG. 14 is a close up view of the battery housing; and
[0041] FIG. 15 is a side view of the unit installed for operation
in the standard wheel chair.
[0042] FIG. 16 is a close up view of a mounting bracket;
[0043] FIG. 17 is a top view of a wheel chair with a cut away;
and
[0044] FIG. 18 is a rear view of a wheel chair with a cut away.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] Referring to the accompanying drawings in which like reference
numbers indicate like elements, FIGS. 1, 2, 3, 4 and 5 are side,
front, side and top views, respectively, of the wheel chair motor
drive of the present invention. FIG. 15 shows the motor drive apparatus
10 engaged with a wheel chair.
[0046] The wheel chair motor drive apparatus 10 is comprised of
a frame 12 and, when assembled, a battery housing 14.
[0047] Drive wheel 20 comprises the housing for a high torque electric
motor (not shown) within the wheel in the depicted embodiment. The
wheel 20 is also the rotor of the electric motor, as well as the
casing for the stator housed within it. The motor and wheel 20 are
coaxial in the depicted embodiment. The wheel 20 also has a friction
surface or tread 22 disposed circumferentially thereon.
[0048] The drive wheel axle 24 supports drive wheel forks 26. The
forks 26 are fixedly attached to a fork bearing journal 28 which
is substantially vertical in the depicted embodiment.
[0049] The frame 12 is essentially comprised of a front frame component
30, arm 32 and battery mount 34.
[0050] A control shaft 40 is fixedly attached to control shaft
bracket 42. The control shaft bracket 42 is attached at pivot 44
to the front frame component 30.
[0051] Control shaft bracket 42 straddles a control shaft positioning
disk 38. Control shaft 40 can pivot around pivot 44 through an arc
that is forward and back, when drive wheel 20 is pointed frontwards.
The position of the control shaft 40 may be selectively maintained
at different positions along its arc of travel. In the depicted
embodiment, bosses and detents (not shown) engaging between control
shaft bracket 42 and an engaging edge of the control shaft position
disk 38 are actuated by control shaft locking pin 46, which spring
biases a pin (not shown) in any of the series of detents (not shown)
along a circumferential surface of control shaft positioning disk
38. An alternative within the scope of the present invention is
a friction engagement between a control shaft locking member and
the control shaft position disk, allowing a continuous range of
selectable positions from control shaft 40. In any case, control
shaft 40 may be positioned in a fully forward location, 40A (FIG.
13). This position, which in the depicted embodiment would place
the top end of the control shaft 40 on or near the floor, allows
for greatly simplified egress and ingress of the wheel chair occupant
in and out of the wheel chair with the wheel chair drive unit 10
positioned under the wheel chair and either engaged with the wheel
chair or ready for engagement with it.
[0052] A fully retracted or backwards position of shaft 40, position
40C (FIGS. 9, 10 and 11), is for stowing the wheel chair drive apparatus
10. Position 40C provides a compact dimension and smaller overall
package size, which facilitates storing the wheel chair drive apparatus
in the trunk of a car, or in provided storage on public transportation
or elsewhere in a home or office.
[0053] Control shaft 40 may also be positioned at table position
40B (in phantom, FIG. 3). The prior art mounted adjustable control
shafts restricted the proximity the wheel chair occupant could achieve
to a table or sink for activities of daily living such as eating
a meal, reading or washing. Position 40B allows a control shaft
40 to move backwards towards the wheel chair occupants lap and allow
the wheel chair occupant to move forward with his or her knees under
a table, desk or sink which in turn facilitates a comfortable distance
for eating, reading, washing or other activities.
[0054] On top of control shaft 40 are located controls, such as
throttle 50, displays (FIG. 12) and handle bars 52.
[0055] Power for the wheel chair drive apparatus of the present
invention is DC. The DC battery is retained within a battery housing
14. This sealed housing is acceptable for public transportation
such as commercial airlines, further easing travel for the disabled,
who would otherwise need to make special arrangements for packaging
an open battery for transportation.
[0056] The battery housing 14 includes a handle 18 and a power
jack receptacle 16. The battery housing 14 is assembled with the
wheel chair drive apparatus 10 by lowering it into the battery mount
34 of frame 12. In the depicted embodiment, the battery mount is
simply two parallel steel rails dimensioned to receive the battery
housing 14 and support its weight flanges on the sides of the top
of the battery housing 14.
[0057] A power cord 60 has a jack 62 that may be engaged with the
corresponding jack 16 during assembly in order that the battery
within housing 14 can be electronically engaged with the electric
motor within drive wheel 20. In the depicted embodiment, the power
cord 60 progresses through front frame component 30 and down one
arm of drive wheel fork 26 and enters the drive wheel casing 20
via a through hole in axle 24.
[0058] This battery pack is much lighter, approximately 30 lbs.,
and is internally fused with an enclosed protected connector. If
needed, the system provides use of a second battery pack, which
can be charging while the first is in use. The battery pack drops
into the rectangular opening of the frame and is held in place by
gravity. Four bolts located on either side of the battery pack,
which holds the cover of the battery pack in place, prevents the
battery pack from dropping through the rectangular opening in the
frame. The connector is polarity keyed and rated at 50 amps with
10,000 insertions. To charge the battery, the connector providing
power to the drive unit is removed from the battery and the battery
charger connector is inserted into the battery pack. It is not necessary
to remove the battery pack from the drive unit while charging. A
connector of this quality requires high contact pressure and therefore
an ejector mechanism 63 is preferred.
[0059] At the rear of the wheel chair drive apparatus 10 is the
swing assembly 70. In the depicted embodiment, the swing assembly
is a lever for casters 72. Swing assembly 70 has at least two positions.
A first position is substantially upright, at right angles with
the battery mount rails 34 (see FIGS. 8, 9, 10, 11 and 15). In this
position, the swing assembly may be engaged with swing assembly
brackets fixedly mounted to the wheel chair further explained below.
In the first position, casters 72 are raised from and disengaged
with the ground or floor. The first position is used for engagement
with the wheel chair and use of the wheel chair drive assembly for
powered driving of the wheel chair. The first position is also used
for storage of the wheel chair drive assembly 10 when being transported
or otherwise not in use (see, FIGS. 9, 10 and 11). With regards
to storage, the first position provides a more compact package size,
and maintains the casters 72 in a position disengaged with the ground.
[0060] Swing assembly 70 is engaged with the battery mounting rails
34 of frame 12 at pivot 74. Movement of pivot 74 allows for a swing
assembly 70 to move into at least one other position. This other
position is depicted in FIGS. 1, 3, 6 and 13. An intermediate position
is show in FIG. 7. There it can be seen that casters 72 are rotated
into a position engaging them with the ground for rolling. Caster
mounts 76 are angled such that the castors roll in the second position
and do not touch the ground in the first position. The caster mounts
76 are fixedly attached to the swing assembly horizontal bar 78.
The swing assembly bar 78 engages with swing assembly mounting brackets,
as is more fully described below. This second position of the swing
arm assembly 70 is maintained in position and prevented from further
backwards rotation by a stop engagement with the battery mounting
rails 34 of frame 12. Although any stop arrangement is within the
scope of the present invention, in the depicted embodiment, the
stop is the leading edge of the horizontal member of the swing assembly,
which comes into stopping contact with the top of battery mounting
rails 34 when the swing assembly 70 has been rotated to a position
engaging the casters 72 with the ground.
[0061] The swing assembly 70 includes a forward extension 80 having
a locking notch 84. When fully engaged with the wheel chair for
driving it, the wheel chair drive apparatus 10 transfers forwards,
backwards and turning drive force to the wheel chair through the
close, fitted engagement of swing assembly horizontal bar 78 with
the horizontal bar mounting brackets, which are fixedly attached
to the wheel chair. Accordingly, it is important that swing assembly
70 be securely maintained in its upright, first position when the
wheel chair drive assembly is in use. This secure maintenance of
the first position is achieved in the depicted embodiment by a locking
lever 86, best seen in FIG. 9. Locking lever 86 slides forwards
and backwards and its rearward aspect is maintained in horizontal
forward and back sliding engagement with battery mount 34 by sliding
arm mount 88, which forstalls undesirable upwards and downwards
movement of locking arm 86. The locking arm 86 is biased towards
maintaining engagement with lock arm notch 84 by a spring 87. A
locking arm release lever 90 is pivotedly attached to a frame 12
at pivot 92 and operated by a user with locking arm release lever
handle 94.
[0062] FIG. 16 depicts one swing assembly or caster lever mounting
bracket 100. FIGS. 6, 7 and 8 depict the mounting brackets fixedly
attached to wheel chair. Attachment devices, such as two U-bolts
and their respective nuts are used to attach each mounting bracket
100 to the frame of the standard wheel chair. Alternative through
holes (not shown) in mounting bracket 100 provide for the adaptability
of mounting bracket 100 for attachment to a variety of standard
wheel chair frames design.
[0063] The mounting bracket has a forward extension 110 which serves
as a guide for assisting the engagement of the horizontal bar 78
of swing assembly with the mounting brackets. Because the guide
flanges 110 are angled to be progressively wider at their forward
aspect, the mounting bracket is able to receive the horizontal bar
78 from a range of directions. Accordingly, ease of engagement of
the drive apparatus 10 with a wheel chair is achieved.
[0064] Mounting bracket 100 is designed with an engagement face
120 which is substantially at right angles to the side portion of
mounting bracket 100 whereon the mounting U-bolts are attached.
This engaging face 120 serves as a rearward stop for horizontal
bar 78 during engagement. Towards the bottom of the mounting bracket
100 the engagement face 120 is configured with a rear stop engagement
face 122, bottom support weight supporting face 124, forward locking
face 126 and entry face 128. Together these components 122-126 comprise
an engagement seat for horizontal bar 178. For a secure seat, the
internal dimensions of faces 122, 124 and 126 are dimensioned to
closely cooperate with the external faces of horizontal bar 78.
Guide face 128 serves to guide horizontal bar 78 into seat 130 as
it is being engaged with the wheel chair for operation.
[0065] Engagement operation is executed by setting up the wheel
chair drive apparatus 10 on the ground, just in front of the wheel
chair. With the wheel chair occupant in the wheel chair and the
control shaft 40 in its upwards position, drive wheel 20 is held
turned 900 to act as a brake. Swing assembly 70 is in its second
"out" position with the casters engaged with the ground.
In the second position of swing assembly 70 maintains the handle
18 of installed battery housing 14 at a first level. This first
level is lower than the level of the wheel chair cross bars in a
standard wheel chair. The wheel chair occupant manually moves his
wheel chair forward until guide flanges 100 engage the rearwardly
projecting horizontal bar 78 and guide it towards seat 130. When
the horizontal bar 78 touches rear engaging face 122, continued
forward motion of the wheel chair will cause swing assembly 70 to
rotate in a clockwise direction as shown progressively in FIGS.
6, 7 and 8. The wheel chair drive of apparatus 10 is held against
being pushed forward by the drive wheel, which is turned 90.degree..
With further forward motion, horizontal bar 78 is pushed downwards
so that the bottom of horizontal bar 78 progresses towards its seat
against bottom engaging face 124. Swing assembly 70 continues to
pivot clockwise direction until it rotates upwards into a substantially
right angle to battery mounting rail 34. The locking notch 84 engages
the lock slide 86 and pushes it forwards until lock slide spring
87 biases lock slide 86 into notch 84 and holds the swing assembly
70 in its right angle, first position. Simultaneously with this
motion, the battery mounting brackets will be raised upwards. Along
with the battery mounting rails being raised, battery 14 and its
handle are raised. Handle 18 is dimensioned such that when the swing
assembly 70 is in its first position, handle 18 engages the cross
bar to the wheel chair frame and holds them in a weight supporting
position. Also simultaneously with the rotation of swing assembly
70, casters 72 are rotated out of engagement with the ground.
[0066] Casters 72, being omni directional, operate with guide flanges
110 to facilitate an automatic mechanic adjustment of alignment
as the swing assembly as the wheel chair and the mounting brackets
are pushed into engagement with the swing assembly by the wheel
chair operator.
[0067] Alternatively, the driver can be installed by setting the
wheel chair brakes and backing the drive apparatus under the chair
under power, which actuates the same mechanisms as described above.
[0068] Comparing FIG. 12 with FIG. 12A illustrates that when the
swing assembly 70 is out and casters 72 deployed, the rear end of
the drive apparatus 10 is lower than its front. Consequently, the
rear end of the delrin slide 19 on top of handle 18 is also lower
than the x-frame member of the wheel chair, which allows the handle
to slide under the x-frame easily. In FIG. 12A, the swing assembly
70 is in, and also up, which raises the rear of the drive apparatus
10 and delrin slide 19 into lifting engagement with the wheel chair
at the x-frame member.
[0069] The weight supporting function of battery handle 18 is through
its engagement with the cross bars of the wheel chair frame. This
engagement is forward of the wheel chair's main wheels axle and
forward of the center of gravity of the wheel chair with its occupant.
Accordingly, raising of the wheel chair drive apparatus 10 by engagement
of swing assembly 70 concomitantly raises the front casters of the
wheel chair off the ground. This prevents interference of these
wheels with the progress of the wheel chair with its bar style or
main wheels or bar style or drive wheel 20 over minor obstacles.
The wheel chair casters are only raised a small vertical distance
however. Accordingly, they serve as anti-tip safety wheels or out
riggers in the event of a sharp turn or hill or ramp that may otherwise
threaten to tip the wheel chair and drive apparatus over.
[0070] In view of the foregoing, it will be seen that the several
advantages of the invention are achieved and attained.
[0071] The embodiments were chosen and described in order to best
explain the principles of the invention and its practical application
to thereby enable others skilled in the art to best utilize the
invention in various embodiments and with various modifications
as are suited to the particular use contemplated.
[0072] As various modifications could be made in the constructions
and methods herein described and illustrated without departing from
the scope of the invention, it is intended that all matter contained
in the foregoing description or shown in the accompanying drawings
shall be interpreted as illustrative rather than limiting. For example,
Thus, the breadth and scope of the present invention should not
be limited by any of the above-described exemplary embodiments,
but should be defined only in accordance with the following claims
appended hereto and their equivalents. |