Wheel chair abstract
A wheel chair, including a frame, with the rear wheels mounted
independently, each on an elongated arm, which extends rearward
from a torsion bar. The center of the torsion bar is normally gripped
against rotation to prevent transmittal of torsion from one end
of the bar to the other, but the torsion bar may be turned through
an arc to raise and lower the rear wheels, so as to maintain the
chair level when going up or down a grade. A leg support panel is
mounted on a linkage to enable it to pivot about an axis corresponding
to the knee axis of the patient and the back support pivots between
upright and horizontal position generally about the hip axis of
the person. A padded support extends upward when the back support
is lowered from its erect position in order to maintain continued
support of the head.
Wheel chair claims
What is claimed as invention is:
1. A wheel chair comprising:
a frame;
a transverse torsion bar rotatably mounted near its ends on the
forward portion of said frame;
a pair of rearwardly extending, elongated wheel support arms non-rotatably
mounted on the ends of said torsion bar;
a rear wheel rotatably mounted at the trailing end of each of said
wheel support arms;
a control arm non-rotatably secured to the mid-portion of said
torsion bar; a hydraulic ram pivoted between said control arm and
said frame so that the position of the piston in said hydraulic
ram will determine the angular disposition of said wheel support
arms, and said hydraulic ram when set holds said mid-portion against
rotation, so that torsion at one end of said torsion bar is not
transmitted to the other end thereof; and
at least one front wheel rotatably mounted at the forward end of
said frame.
2. The vehicle defined by claim 1 including:
a rotary motor mounted on each of said elongated wheel support
arms;
a gear driven by each of said motors; and
a resilient tire on each of said rear wheels engaged so as to be
driven by one of said gears.
3. A wheel chair comprising:
a frame;
at least one front wheel and a pair of rear wheels rotatably mounted
on said frames;
a seat supported on said frame;
a back-support carried at the rear of said frame;
a leg support panel at the forward end of said frame;
a transverse leg support shaft rotatably mounted on the forward
end of said frame;
a pair of extensible linkages, each including two adjacent pivoted
links, one secured to said leg support shaft to rotate therewith
and the other pivoted to the forward end of said frame, and two
remote links pivoted at one pair of adjacent ends to said adjacent
links and at the other pair of adjacent ends to a side of said support
panel so that when said leg support shaft is turned upward, said
linkage is extended to pivot said panel about a transverse axis
located above said shaft; and means for turning said shaft partially
in either direction.
4. The wheel chair defined by claim 3 wherein said back-support
comprises:
a pair of posts pivoted at their lower ends to the rear end of
said frame;
a back-support panel slidable on said posts; and
a restraining link pivoted at opposite ends to said frame and said
back-support panel so that said back-support panel remains at a
fixed distance from approximately the user's hip axis throughout
pivotal movement of said posts; and
means for pivoting said posts between upright and generally horizontal
positions.
5. The wheel chair defined by claim 4 including:
a head support;
complementary upright slides and slideways on said head support
and back support respectively;
spring means biasing said head support toward an elevated position;
a latch operative to hold said head support in retracted position;
and
means operative to release said latch when said posts are moved
from their upright positions.
6. The wheel chair defined by claim 4 including:
a head support;
a pair of elongated slide members secured to said head support
to depend therefrom;
a pair of slideways on said back-support panel slidably receiving
said slide members;
compression springs biasing between said head support and said
back-support panel;
a lever pivoted on said back-support panel to swing between a normal
depressed to an elevated position;
a tension member secured to the free end of said lever;
a pin intermediate the length of said lever;
a pull rod attached at its lower end to said posts to pivot therewith;
and
a longitudinal slot near the upper end of said slot receiving said
pin.
7. The wheel chair defined by claim 3 including:
a pair of spaced arm support posts; and
means operative to pivot said support posts between upright, elevated
positions and generally horizontal, lower positions to facilitate
removal of a person from the chair onto a horizontal support.
8. The wheel chair defined by claim 3 including:
a transverse torsion bar rotatably carried at the forward portion
of said frame;
a pair of elongated, rearwardly extending wheel support arms non-rotatably
mounted on the ends of said torsion bar;
a rear wheel rotatably mounted at the trailing end of each of said
wheel support arms; and
at least one front wheel rotatably mounted at the forward end of
said frame.
9. The vehicle defined by claim 8 including:
means on said frame gripping the mid-portion of said torsion bar
against rotation so that torsion at one end of said bar is not transmitted
to the other end thereof.
10. The vehicle defined by claim 9 wherein:
said gripping means include a control arm secured to said torsion
bar; and
a reciprocable, force-delivering member pivoted to the end of said
control arm so that operation thereof turns said torsion bar to
swing said wheel support arms selectively up and down.
11. The wheel chair defined by claim 8 including:
tires with treads thereon on said rear wheels;
a rotary drive on each of said wheel support arms; and
a drive gear driven by each of said rotary drives and engaging
one of said rear wheels.
12. A wheel chair comprising:
a frame;
front and rear wheels rotatably mounted on said frame;
a seat support on said frame;
a back-support carried at the rear of said frame comprising:
a pair of posts pivoted at their lower ends to the rear end of
said frame;
a back-support panel slidable on said posts; and
a restraining link pivoted at opposite ends to said frame and said
back-support panel so that said back-support panel remains at a
fixed distance from approximately the user's hip axis throughout
pivotal movement of said posts; and
means for pivoting said posts between upright and generally horizontal
positions.
13. The wheel chair defined by claim 12 including:
a head support;
complementary upright slides and slideways on said head support
and back support respectively;
spring means biasing said head support toward an elevated position;
a latch operative to hold said head support in retracted position;
and
means operative to release said latch when said posts are moved
from their upright positions.
14. The wheel chair defined by claim 12 including:
a head support;
a pair of elongated slide members secured to said head support
to depend therefrom;
a pair of slideways on said back-support panel slidably receiving
said slide members;
compression springs biasing between said head support and said
back-support panel;
a lever pivoted on said back-support panel to swing between a normal
depressed to an elevated position;
a tension member secured to the free end of said lever;
a pull rod attached at its lower end to said posts to pivot therewith;
and
a longitudinal slot near the upper end of said slot receiving said
pin.
15. The wheel chair defined by claim 12 including:
a pair of spaced arm support posts pivotally mounted on each side
of said frame;
an arm rest spanning said support posts; and
means operative to pivot said support posts between upright, elevated
positions and generally horizontal, lower positions to facilitate
removal of a person from the chair onto a horizontal support.
Wheel chair description
BACKGROUND OF THE INVENTION
Many wheel chairs in use today subject the users to unnecessary
and often severe physical punishment. The wheels are generally mounted
directly on the frame so that any bump or depression impacted by
either wheel is delivered through the frame to the rider. Over years
of use, this often results in compacting the spinal column.
Some existing wheel chairs provide some limited adjustment to the
back and leg supports but it is not believed that there exists a
wheel chair capable of supporting a patient in any selected position
between upright and horizontal; and it is not believed that there
is a wheel chair which is capable of allowing the user to lie prone
thereon for a nap.
OBJECTS OF THE INVENTION
It is an object of this invention to provide a wheel chair that
allows little or no road shock, which may be encountered by a wheel
to be transmitted to the chair itself.
It is further object of this invention to provide a wheel chair
that enables each wheel to absorb road impact without transmitting
same to the other wheel.
It is a further object of this invention to provide a wheel chair
that is capable of supporting the patient's back in any selected
position between upright and horizontal.
It is a further object of this invention to provide a wheel chair
which is capable of supporting the legs of a person in any selected
position between upright and horizontal.
It is a further object of this invention to provide a wheel chair
with a leg support that swings through selected positions about
an axis corresponding generally with the user's own knee axis.
It is a further object of this invention to provide a wheel chair
having a back support which swings through selected positions about
an axis corresponding generally to the user's own hip axis.
It is a further object of this invention to provide a wheel chair
having a back support which is capable of being pivoted from a normal
erect position to a selected inclined position, while supporting
the user's head in any position back from upright position.
It is a further object of this invention to provide a motorized
wheel chair that is easy to handle and is highly maneuverable.
Other objects and advantages of this invention will become apparent
from the description to follow, particularly when read in conjunction
with the accompanying drawings.
SUMMARY OF THE INVENTION
In carrying out this invention, I provide a wheel chair wherein
each rear wheel is driven independently in either direction by direct
engagement of a motor-driven gear with the tread of the rubber tire.
A series of hydraulic rams easily controlled by a joy stick switch
at the hand of the user are operated selectively to pivot the back
support about an axis corresponding generally to the hip of the
user and a leg support about an axis corresponding generally to
the knee axis of the user. The front "follower wheels"
are free to pivot to adapt to the direction of movement and are
spring mounted for a limited shock absorbing action. The main rear
driving wheels are mounted on elongated cantilever beams which are
secured to a torsion bar, which in turn is rotatably mounted at
the forward end of the frame. However, the center of the torsion
bar is gripped against rotation so that any road impact encountered
by one wheel can not be transmitted completely along the length
of the torsion bar to the other wheel. Hence, each wheel is mounted
independently in shock absorbing suspension. The arm that normally
holds the center of the torsion bar against rotation may be pivoted
to turn the bar through a limited arc to raise and lower the back
wheels so that the seat may be maintained generally horizontal on
either upgrades or downgrades. When the back rest is moved from
its upright position, spring means are released to extend a head
support to ensure cushioned support of the head in any position
out of upright position. Arm rests may be lowered from their normal
upright position to facilitate side access to the wheel chair.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a front side view in perspective of the wheel chair of
this invention, showing in phantom several selected positions of
the components thereof;
FIG. 2 is a partial side view of the vehicle frame showing operation
of the main wheel mounting;
FIG. 3 is an enlarged partial view in perspective showing a portion
of the wheel mounting;
FIG. 4 is a partial view of the frame showing operation of the
wheel adjustment means;
FIG. 5 is an enlarged partial view of the torsion bar wheel support
mounting;
FIG. 6 is a partial view in perspective showing the operation of
the leg support mechanism;
FIG. 7 is a partial view in perspective showing operation of the
arm rest mechanism;
FIG. 8 is a rear view in perspective showing components of the
back support system;
FIG. 9 is a view of the wheel chair in perspective in its horizontal
mode; and
FIG. 10 is a view in perspective from behind and below the back
support showing operation of the head support device.
DESCRIPTION OF A PREFERRED EMBODIMENT
The Wheel Chair
Referring now to FIG. 1 with greater particularity, the wheel chair
of this invention includes a frame 12 mounted on main drive wheels
14 with tires 15, as well as small front wheels 16. Carried on the
frame 12 is a seat 18 and a back support assembly 20, which as indicated
in phantom, may be pivoted back from an upright position shown in
solid lines to a substantially horizontal position (FIG. 9). A head
support 22, which is carried on posts 24 is normally depressed as
shown in solid lines so as not to obstruct the vision of the patient
as he looks back over his shoulder. However, when the back support
20 is moved from its horizontal position the head support is raised,
as shown in phantom, to support the head while the patient is lying
prone. Handgrips 26 carried on posts 28 which are part of the back
support assembly 20 enable the wheel chair 10 to be pushed by an
attendent, if desired. For this purpose, suitable clamping means
or the like may be provided to disengage the motor drive.
A leg and foot support assembly 30 is mounted to be rotated from
its normal upright position when the patient is in sitting position
to a substantial horizontal position when the patient is prone.
In addition, arm rests 32 are movable as indicated from an upright
position shown on solid lines to a depressed position wherein, a
patient lying prone on the wheel chair 10 in horizontal configuration
(FIG. 9) may be rolled off onto a bed.
Each rear wheel 14 is driven from a motor 33 through a relatively
wide gear 34 that engages the rubber tread 35 of the tires 15. The
direction of drive for each wheel may be under the control of a
"joy stick" type switch 33a.
The Suspension Mounting
Referring now to FIGS. 2 through 5, the frame 12 of the wheel chair
may include a pair of rigid posts 36 to each of which are secured
the opposite ends of a generally horizontal, elongated u-shaped
tubular cantilever beam 38, the beams being secured together by
cross braces 39 rotatably carried in the rigid posts 36, is a torsion
bar 40, preferably encased in a sleeve 41 at the opposite ends of
which are splined or otherwise secured a pair of rearwardly extending
cantilever beams 42. At the trailing ends of the beams 42 are axles
44 for rotatably mounting the rear, drive wheels 14.
The center of the torsion bar 40 is gripped by an actuating arm
46 which, in turn, is pivotally mounted at the end of a piston rod
48 reciprocable in a hydraulic ram 50 mounted on the frame 12. In
normal operation, the piston rod 48 is fixed so that the center
of the torsion bar is held against rotation. Thus, any torsion delivered
at one end thereof is not transmitted to the other. Hence, one wheel
14 of the wheel chair 10 can impact a bump or depression and the
shock will be absorbed in the torsion bar 40, without delivering
similar torsion to the other wheel 14. This provides greater stability
and the absorption of the shock greatly improves the comfort of
the ride.
With the drive motors 33 and pinions 34 mounted on the wheel support
cantilever beams 42, drive to the wheels 14 is not interrupted by
oscillation of the beams 42 as a result of road impacts.
When it is desired to adjust the wheel chair 10 to an upgrade or
downgrade, the rear wheels 14 may be raised or lowered by retracting
or extending the piston rod 48, as illustrated in FIGS. 2 and 4.
For example, when moving down the isle of a theatre, the operator
may wish to raise the rear drive wheels 14 to a level wherein the
seat 18 is relatively horizontal. To do this, the hydraulic ram
50 is actuated to retract the piston rod 48, as indicated in solid
lines in FIG. 4. This turns the torsion bar 40 clockwise in FIG.
4, and pivots the cantilever suspension beams 42 upward. This action
may be reversed to go back up the aisle.
At the front of the frame 12 the small wheel 16 is rotated in a
yoke 52 which is free to pivot in a bearing 54. The yoke 52 is pivoted
to a base plate 58 and is spring mounted at 60 to further cushion
the ride.
The Leg and Foot Support Assembly
Referring now to FIGS. 1 and 6, the leg and foot support assembly
30 has a panel 62 to support the backs of the legs when in raised
position and a foot rest 64. The panel 62 is pivotally mounted on
the ends of two links 66 and 68 at the end of scissors type, extensible
linkage 19, which at the near end includes a link 70 which is pivoted
to a link 71 and to bracket 72, secured to the rigid post 36 of
the frame. Scissored with link 71 is a link 74 which is secured
on the end of a shaft 76 to rotate therewith. Hence, when the shaft
76 is turned counterclockwise, the link 74 is pivoted upward carrying
the link 71 with it and, thereby, extending the entire scissors
linkage 69.
The scissors linkage 69 is designed so that the panels 62 swings,
not about the axis of the shaft 76 but about an axis K displaced
upward therefrom and corresponding generally to the axis of the
patient's knee. Hence, the panel 62 can be raised without changing
the location of the foot rest 64, or any other part of the panel
62 relative to the patient's legs.
An arm 78 secured to the shaft 76 is pivoted to a piston rod 80
carried in a hydraulic ram 82, which is selectively operated to
raise, and lower the platform 62 as described.
The Arm Support System
Referring now to FIGS. 1 and 7, the arm rests 32 are supported
on plates 89 which, in turn, are pivotally mounted at the tops of
posts 84. The posts 84 are secured to front and rear shafts 85 and
86 which are rotatable on the frame 12. Thus, the posts 84 and plates
83 together form a parallelogram structure to pivot together. An
arm 88 carried on one of the shafts 86 is pivotally secured to the
end of a piston rod 90 which is driven by a hydraulic ram 92. Hence,
when the hydraulic ram is operated to retract the piston rod 90,
the arm 88 moves to the position shown in phantom to pivot the arms
down and bring the arm rests 32 to depressed positions at or below
the level of the seat 18 to enable side entry to the wheel chair
10.
The Back Support Assembly
Referring now to FIGS. 8 to 10 the back support assembly 20 includes
a rigid sub-frame 94, which includes the upright posts 28 which
carry the hand grips 26. The sub-frame 94 is pivoted at 96 about
the vehicle frame 12 and is adapted to be pivoted to a selected
position by operation of the hydraulic ram 98 which is pivoted to
a depending arm 100 on the sub-frame 94.
Secured to the back side of the back support 102 are two series
of sleeves or bushings 104, which are slidable on verticle posts
106, which are secured at their lower ends to the sub-frame 94,
and at their upper ends to cross braces 107 welded to the hand grip
posts 28.
A link 108 is pivoted between the back support 102 and the vehicle
frame member 38 so that as the back rest assembly swings back, the
back support 102 is pulled to slide down the rods 106 and maintain
the same position relative to the pivot 112 on the vehicle frame
member 38. This is designed to cause the back rest 102 to swing
approximately about the hip axis of the patient, so that the back
support 102 remains relatively fixed with respect to the patients
back being supported. Hence, the chair can be designed to provide
optimum back support for the particular patient and such support
remains relatively fixed throughout movements of the back support
assembly 20.
The Head Rest
Referring to FIGS. 8 and 10, the padded head rest 22 is, as previously
described, carried on a pair of posts 24 which are slidably carried
in sleeves 114 secured to the back of the back support 102.
In upright position, the head support 22 is held in its lower,
retracted position against the action of springs 116 by means of
a suitable tension member 118 which is pulled down by lever 120
pivoted on the back of the back support 102. The lever is in turn
normally held in its lower position by engagement of a pin 122 thereon
against the top of a slot 124 at the upper end of a bar 126 which
is secured at 128 to the sub frame 94.
In operation, as the back support sub frame is pivoted back from
the position shown in FIG. 8, the back support 102 is pulled down
the rods 106 so that the pin 122 on lever 120 tends to slide down
the slot 124. During initial movement of the back assembly 120 this
movement is taken up by the springs 116 and, with the pin 122 located
on the lever 120 so that the end of the lever moves through an arc
of about twice the length, considerable movement of the wire 118
and head rest is enabled in the first increment of movement of the
sub-frame 94. Accordingly, the head rest 122 is immediately projected
to its extended position to give maximum support to the head throughout
movement of the back support 122.
As illustrated particularly in FIG. 9 when the back support assembly
is moved to its lowered position, the leg support assembly may also
be raised to horizontal position, or anywhere intermediate, and
the patient may take a nap directly on the wheel chair. If it is
desired to move the patient to a bed, the arm rests 32 may be depressed
to their lower positions shown in FIG. 9 and the patient lifted
or rolled directly onto the bed.
When it is desired to return the patient to upright position from
prone position on the chair 10, the hydraulic ram 98 is again actuated
to raise the back rest, and the ram 82 (FIG. 5) is operated to swing
the leg support down. These operations may be done simultaneously,
but the control switch is preferably conditioned to enable only
one mode change at a time in order to lessen the likelihood of the
patient becoming disoriented.
In any event, as the back support assembly 20 approaches its upright
position, the pin 22 will have reached the top of the slot 124 and,
thereafter, the pull bar 126 will commence to pull the lever 120
down to retract the head rest 22, again at about a 2 to 1 ratio,
against the action of the springs 116. With the headrest so retracted
the patient can look back over his shoulders with view unobstructed.
While this invention has been described in conjunction with a preferred
embodiment thereof, it is obvious that modifications and changes
therein may be made by those skilled in the art to which it pertains,
without departing from the spirit and scope of this invention, as
defined by the claims appended hereto. |