Wheel chair abstract
An improved step-climbing wheel chair with integral retractable
ramps for ascending or descending a step, curb or the like. The
conveyance is provided with a two-speed transmission capable of
driving the wheel chair on level terrain at conventional speeds
or selecting a low speed high torque capability for driving the
conveyance up an inclined ramp. The invention further contains a
self-leveling chair seat which automatically maintains the occupant
in a level seated position regardless of the inclined position assumed
by the wheel chair frame, thereby contributing to the stability
of the wheel chair and the safety of the occupant.
Wheel chair claims
I claim as my invention:
1. In a wheel chair for ascending and descending a step, curb or
the like, the combination of:
a frame with castor wheels and drive wheels mounted thereon;
a pair of elongate substantially flat ramps;
a foldable, extendable and retractable ramp supporting assembly
carrying said ramps and pivotally mounted on said frame;
a self-leveling seat pivotally mounted on said frame;
a first power drive means interconnecting said chair and frame
and automatically energized to maintain the said seat in a level
position regardless of an inclined position assumed by said frame;
a control means carried on said ramp supporting assembly for extending,
positioning, retracting and folding said ramps relative to said
frame for traverse by said castor and drive wheels; and
a second power drive means mounted on said frame and including
a multi-speed transmission for driving said drive wheels on level
terrain at conventional speeds and at a low speed with high torque
up said ramps and functioning as a speed restraint while descending
said ramp.
2. A wheel chair as defined in claim 1 wherein said ramp supporting
assembly includes manually actuable control handles slidably mounted
therein for moving generally parallel to said ramp.
3. A wheel chair as defined in claim 2 including brake means for
locking said control handles relative to said ramp supporting assembly.
4. A wheel chair as defined in claim 3 including second control
means carried on said control handles for controlling said second
power drive means.
5. A wheel chair as defined in claim 1 wherein said seat is pivotally
mounted on said frame at a pivot point below the seat whereby the
seat is pivoted forwardly when the wheel chair is ascending and
pivoted rearwardly when the wheel chair is descending.
6. A wheel chair as defined in claim 1 including auxiliary ramps
pivotally mounted at and extending from each end of each of said
ramps.
Wheel chair description
REFERENCE TO RELATED DISCLOSURE
This invention is in part the subject of Disclosure Document No.
050052, filed June 11, 1976.
BACKGROUND OF INVENTION
This invention relates to a conveyance intended primarily for use
by handicapped persons or invalids which are normally limited to
travel on a level terrain.
The chief aim of the present invention is to provide a self-contained
conveyance which will enable a handicapped person or invalid to
cope safely with problems encountered in driving the conveyance
into or out of an automobile, ascending or descending a street curb,
a step or other obstructions which may be encountered at home, in
a factory, or out-of-doors without the aid of an attendant, thus
providing a freedom of mobility previously unknown to occupants
of conventional wheel chairs.
SUMMARY AND OBJECTS OF INVENTION
A general object of the invention is to secure the foregoing advantages
in a conveyance which is power driven with a minimum amount of exertion
on the part of the seated occupant, for forward or rearward propulsion
as well as making turns in one direction or the other within a turning
circle equivalent to conventional wheel chairs.
Another object of the invention is to provide a two-speed transmission
capable of driving the wheel chair on a level terrain at conventional
speeds or selecting a low speed high torque capability for driving
the conveyance up its inclined ramps into or out of a van-type automobile
or other vehicles, ascending or descending a street curb or step.
Another object of the invention is to provide a ramp means that
is slidingly and pivotally secured to the wheel chair frame and
manually extended and inclined by the occupant in front of the castor
wheels for ascending or descending an automobile floor board, a
curb or step. After the castor and drive wheels traverse the said
ramps, the ramps are manually retractable and placed in the traveling
position above the castor and drive wheels until subsequently required.
The traveling position of the ramps are housed slightly inboard
of the wheels thus permitting the wheel chair to pass through narrow
doorways without interference from the ramps.
The foregoing objects, advantages, features and results of the
present invention, together with various other objects, advantages,
features and results thereof which will be evident to those skilled
in the art to which the invention relates in light of this disclosure,
may be achieved with the exemplary embodiments of the invention
illustrated in the accompanying drawings and described in detail
hereafter.
DESCRIPTION OF DRAWINGS
In the drawings:
FIG. 1 is a side elevational view of the present invention, illustrating
the conveyance ascending a curb by use of the retractable ramps.
FIG. 2 is a rear elevational view of the conveyance as it appears
when viewed from the right of FIG. 1 in the curb ascending position.
FIG. 3 is a skeletal side elevational view of the conveyance illustraing
the ramps in a folded position for traveling on level terrain.
FIG. 4 is an enlarged vertical section taken as indicated along
the angled arrows IV--IV of FIG. 1 illustrating details of the retractable
ramps and chair leveling means.
FIG. 5 is an enlarged fragmentary vertical view partly in section
illustrating the hand control device.
FIG. 6 is an enlarged fragmentary vertical view partly in section
illustrating the fixed and extendable control bars with solenoid
brake means.
FIG. 7 is an enlarged fragmentary side elevational view of the
pendulum activated switch for automatically energizing the chair
stabilizing drive motor.
DESCRIPTION OF EXEMPLARY EMBODIMENT OF THE INVENTION
Referring to FIGS. 1, 2, and 3 of the drawings, the conveyance
of the invention comprises a reduction gear motor 1 secured to frame
5. The motor 1 drives the belt 2, the latter in turn drives a two-speed
planetary transmission 3. The transmission 3 provides a selective
high speed drive for traveling on a level terrain and a low speed
high torque means for driving the conveyance up an inclined ramp.
Selective changes in speed are accomplished by activating a friction
brake 4 by means of a hand lever 4' or a remote controlled solenoid
(not shown). The transmission 3 drives chain 6 in turn drives the
sprocket 7 and wheel 8. The castor wheel 9 is pivotally mounted
to the frame 5. The mounting sleeve is positioned on the outboard
side of frame 5 to permit the castor wheel 9 and the drive wheel
8 to be in direct longitudinal alignment in order to minimize the
width of the channel bar ramp 10. The main ramp 10 is illustrated
bridging a street curb with the lower auxiliary hinged ramp 11 positioned
on the street level while the upper auxiliary hinged ramp 11 is
positioned on the sidewalk level. The double faced slip resistant
neoprene cleats 12 are secured to the lower surface of ramp 10.
When the ramp 10 is inclined in the opposite direction for descending
from the sidewalk to the street, the oppositely angeled face of
the cleats 12 will become engaged with the sidewalk and street surfaces
in the same manner as previously described. An equalizing bar 13
is pivotally connected to the inboard side of auxiliary ramps 11
thereby maintaining an equal angular relationship between the ramps
11, ramp 10 and the sidewalk and street surfaces. The foregoing
arrangement facilitates positioning the ramps 10 and 11 respectively
for ascending or descending from street level or vice versa. The
slip resistant neoprene wedges 14 are secured to the lower surface
of the auxiliary ramps 11. The wedges 14 are provided to assist
the cleats 12 in opposing the force generated by the wheel chair
drive means as the castor wheels 9 enter upon the ramps 11.
A pair of hinged levers 15 are pivotally connected to the outboard
side of ramp 10 and the opposite ends of the levers 15 are pivotally
connected to the longitudinally extendable ramp bar 16.
Referring now to FIG. 4 the ramp bar 16 is slidingly engaged to
the "H" bar 17, the latter in turn is slidingly engaged
to the fixed retainer bar 18, the latter in turn is pivotally secured
to the fulcra bolt 19, the latter in turn is secured to the bracket
20, which in turn is secured to the frame 5. The above arrangement
permits the ramps 10 to be positioned in front of the castor wheels
9, the conveyance to traverse the ramps 10 and retract the ramps
10 after the conveyance completes the transit of the ramps 10 for
recycling in the previously described operation. The vertical positioning
bar 21 is slidingly engaged between the bracket 22 and the ramp
bar 16. The lower end of the positioning bar 21 is secured to the
ramp 10 and the upper end is secured to the horizontally fixed handle
bar 23. The above arrangement permits the operator to move the ramps
10 in a forward or rearward position and raise or lower the ramps
10 and to incline or decline the ramps 10 about the fulcra bolt
19. A similar movement of the ramp assembly occurs as the conveyance
traverses the subject ramps 10. The handlebar 23 supports a slidingly
engaged "H" bar 24, the latter in turn supports a slidingly
engaged handle bar 25, the latter in turn has a "T" bar
rail 26 secured thereto. The rail 26 supports a slidingly engaged
control handle 27. The handle 27 is locked to the rail 26 by the
means of a spring urged brake 28 (see FIG. 5). The brake is released
by hand lifting the lever 29 thereby permitting the control handle
27 to slide to the rear end of the rail 26, which will facilitate
positioning the ramps 10 in front of the castor wheels 9 when ascending
or descending a curb or step. The control handles 27 are also provided
with a pair of electrical SPDT switches 39, which in turn energize
the independent motors 1 to effect a steering means and to drive
the conveyance in a forward or rearward direction. The handles 27
further contain a solenoid control switch 30, which in turn energizes
a pair of solenoids 31 and 32 (See FIGS. 4 and 6). The electrical
wires connecting the switches 30 and 39 to their respective solenoids
31 and 32 and motors 1 are not shown but can be contained in a precoiled
self-supporting cable with resilient helical coils having built-in
memories biasing them in to contracted states when extended and
released. The above arrangement provides electrical continuity as
the ramps 10 are extended forward of the castor wheels 9 and as
the conveyance traverses the ramps 10. The previously mentioned
solenoids 31 and 32 are respectively secured to the underside of
the fixed handle bar 23 and to the extendable handle bar 25. The
following is a description of the solenoid 31 shown in FIG. 6. The
armature 33 is pivotally connected to link 34, which in turn is
pivotally connected to the brake lever arm 35, which in turn is
pivotally mounted to bracket 36, the latter in turn is secured to
the handle bar 23. When the solenoid actuated brake arm 35 is forced
into contact with the slidable "H" bar 24, the "H"
bar 24 becomes fixed in relation to the fixed handle bar 23. Likewise
the simultaneous actuation of solenoid 32 will lock the extendable
handle bar 25 to the "H" bar, thereby establishing a fixed
relationship between the handle bars 23, "H" bar 24 and
handle bar 25. The solenoid 32 is secured to the rear end of the
handle bar 25 and the solenoid 31 is secured to the forward end
of handle bar 23, thereby permitting the brake arms 35 to remain
in contact with the "H" bar 24 regardless of the extendable
or retractable positions of the bars 23, 24 and 25 in relation to
each other. The "H" bars 17 and 24 are provided with dead
ended grooves 37, which in turn receive the screw stops 38 to limit
their respective travel in relation to the fixed bars 18 and 23
and also to the extendable bars 16 and 25.
The solenoid brakes 31 and 32 when energized will lock the handle
bars 23 and 25 and permit the operator to extend the ramps 10 from
the traveling position (to be explained later) in front of the castor
wheels 9. De-energizing the solenoids 31 and 32 permit the handle
bars 23 and 25 to become slidingly engaged in relation to each other
permitting the operator to hold the control handles 27 in a comfortable
position adjacent to the chair arms 50 (See FIGS. 1 and 2) as the
conveyance tranverses the ramps 10. While traversing the ramps 10
the hand brake 29 of the control handle 27 is released permitting
the handle 27 to slide to the forward end of rail 26. After the
conveyance completes the transit of the ramps 10, the operator lifts
the handle bars 23, 24 and the attached positioning bar 21 and the
ramps 10, thus causing the hinged levers 15 to fold as shown in
FIG. 3. The operator then pulls the folded ramps 10 up and over
the fender 40 by means of the handle bars 23 and 25. In order to
move the ramps 10 into a forward and traveling position, it will
be necessary for the operator to make two or three pulling and retracting
strokes of the handle bars 25 which is accomplished by alternatingly
energizing the solenoids 31 and 32 and pulling forward one stroke,
then de-energizing the solenoids 31 and 32, then sliding the handle
bar 25 rearward and re-energizing the solenoids for an additional
stroke forward until the ramps 10 are housed for traveling and are
in position to be extended for recycling as previously described
at the approach of the next curb or step.
Chair Stabilizing Assembly
A self-leveling chair 51 is pivotally connected at 52 to the frame
5 (See FIGS. 1, 2, and 4). A chair stabilizing motor 53 is secured
under the battery box 54, the latter is secured to the chair 51.
The motor 53 has a pair of flexible drive cables 55, which in turn
drive gear nets 56. The gear nuts 56 are pivotally connected at
57 to the chair 51. The gear nuts 56 are threadably engaged to the
threaded drive shaft 58, the latter in turn is pivotally connected
at 59 to the brackets 60, which in turn is secured to frame 5 of
the conveyance. The reversible motor 53 is energized by the stabilizing
switch 65 (See FIGS. 1 and 7) which is secured to the chair 51.
When the conveyance starts to ascend or descend the ramps 10, the
pendulum 66 tends to stand in a vertical position while the chair
51, switch box 65 and the attached fulcra pin 67 tend to rotate
about the pendulum 66 and will continue to rotate until one of the
electrical contacts 68 engages a mating contact 69 which is secured
to the pendulum 66 thus automatically energizing the motor 53 and
driving the gear nuts 56 until the chair is returned to a level
position and the contacts 68 and 69 become disengaged and stop the
motor 53. The foregoing assembly will tend to maintain the chair
in a level position regardless of the angle of inclination of the
conveyance. The adjusting screws 70 are provided to alter the range
between the contacts 68 and 69 to prevent short-cycling or excessive
angular movement of the chair before the motor 53 is energized.
An adjusting screw 71 and dampening washer 72 is provided to adjust
the friction against the pendulum 66 thus restricting the pendulum
from swinging too freely and causing the motor 53 to short cycle.
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