Wheel chair abstract
An auxiliary drive means removably mountable to a wheel chair.
An auxiliary frame includes a wheel rotatably thereto which is driven
by a hand crank and chain combination. A hand crank is mounted to
a pivotally and telescopically adjustable steering post. A pair
of chains connect the hand crank to the wheel. The auxiliary frame
is mounted to the vertical posts of a wheel chair and includes a
pair of threaded members to adjust mounting brackets provided on
the auxiliary frame facilitating mounting of the frame to different
configured wheel chairs.
Wheel chair claims
The invention claimed is:
1. An auxiliary drive apparatus mountable to a wheel chair comprising:
an auxiliary frame removably mountable to a wheel chair, said auxiliary
frame including a first pair of posts engaging brackets spaced apart
a maximum distance when mounted to said wheel chair, said brackets
being movably mounted to said frame and movable apart to a second
distance less than said maximum distance to allow mounting and unmounting
of the frame to said wheel chair;
a wheel rotatably mounted to said frame;
a hand crank movably mounted to said frame;
connecting means engaged with said wheel and said hand crank and
operable to drive said wheel to move said wheel chair as said hand
crank is moved;
adjustment means on said frame and operably associated with said
brackets being operable to adjust spacing between said brackets
to change the maximum distance said brackets may be spaced apart
allowing mounting of said frame to different wheel chairs, said
frame including a first telescopically constructed rod with opposite
ends upon which said brackets are mounted, said adjustment means
including a threaded member having an end fixedly connected to one
of said opposite ends and also including a tubular assembly with
an end fixedly connected to the other of said opposite ends, said
tubular assembly includes a captive, internally threaded, rotatable
fastener in meshing engagement with said threaded member which projects
into said tubular assembly, said rotatable fastener upon rotation
changes the distance between said opposite ends, and wherein:
said frame includes a steering post with a proximal end pivotally
mounted to said frame and a distal end with said hand crank mounted
thereon; said connecting means includes sprocket means rotatably
mounted at said proximal end, a first continuous chain operably
connected to said wheel and said sprocket means, and a second continuous
chain operably connected to said hand crank and said sprocket means,
said steering post is telescopically constructed;
said tubular assembly includes a pair of tubes with adjacent ends
joined together forming a knee action joint located between said
pair of tubes and also between said threaded member and said other
opposite end with said tubular assembly further includes a sleeve
movably mounted to one of said pair of tubes to hold said pair of
tubes straight when positioned around said joint keeping said brackets
spaced apart said maximum distance, said sleeve movable to a position
allowing said joint to bend moving said brackets apart said second
distance, said threaded rod and said pair of tubes extend in a straight
line when said sleeve is positioned around said joint, said tubular
assembly further includes a helical spring extending around one
of said pair of tubes and in contact with said sleeve urging said
sleeve to a position extending around said joint; and
said tubular assembly being constructed to position said sleeve
at all times apart from said threaded member and said internally
threaded rotatable fastener.
2. The drive apparatus of claim 1 wherein said sprocket means includes
a cylindrical bearing rotatably mounted to said frame and having
fixedly secured thereto a pair of sprockets rotatable together with
one sprocket in meshing engagement with said first chain and another
sprocket in meshing engagement with said second sprocket, said cylindrical
bearing including a plurality of axially extending grooves formed
on the circumference thereof receiving said sprockets and limiting
relative motion between said bearing and said sprockets, said sprocket
means further includes an axle mounted to said frame having said
bearing rotatably mounted thereto, said sprocket means including
a bolt threadedly received by said axle and securing said bearing
thereon.
Wheel chair description
BACKGROUND OF THE INVENTION
This invention is in the field of wheel chair construction and
more particularly auxiliary drive means and the mounting thereof
to wheel chairs. Wheel chairs are not particularly designed for
use over long distances. As a result, various auxiliary drive means
have been provided to increase the range of the wheel chair. In
one form, a hand crank is provided which is operatively associated
with the wheels by means of a chain. Three different versions are
shown in the U.S. Pat. Nos. 3,485,510, issued to J. Merlan on Dec.
3, 1969; 3,994,509, issued to J. Schaeffer on Nov. 30, 1976 and
4,274,651, issued to H. H. Dumont on June 23, 1981. A similar tricycle
arrangement is shown in the U.S. Pat. No. 4,109,927, issued to R.
L. Harper on Aug. 29, 1978.
Typically, the drive means is designed to be removably mounted
to the front vertical post of the wheel chair with a hand crank
provided for use by the operator. Such a type is shown in the aforementioned
U.S. Pat. No. 3,485,510 and is also available from Orthopedic Systems,
Inc., Route 1, Box 136A, Nelsonville, Ohio 45764 and Fabrique Par:Unicycle
Inc., 2143, Rue St.-Patrick, Montreal, Quebec, Canada.
Disclosed herein is an improved drive means over the latter mentioned
drive means. The improved version disclosed herein is particularly
advantageous in that it is easily mounted to and removed from a
variety of different sized and configured wheel chairs. In U.S.
Pat. No. 3,485,510, the drive means in an alternate embodiment includes
a telescopic rod adjustable to fit different spacings of the vertical
wheel chair posts. The adjustment means of the mounting structure
disclosed herein includes an adjustable in line threaded member
to facilitate different spacing of the wheel chair vertical post.
Further, the steering post of the drive means may be pivoted and
telescoped to the exact position of the person sitting in the wheel
chair facilitating ease of use. A pair of continuous roller chains
are used in lieu of the prior approach of using a single roller
chain thereby enabling the hand crank to be more accurately positioned
with respect to the user's hands.
SUMMARY OF THE INVENTION
One embodiment of the present invention is an auxiliary drive apparatus
mountable to a wheel chair comprising an auxiliary frame removably
mountable to a wheel chair, the auxiliary frame including a first
pair of posts engaging brackets spaced apart a maximum distance
when mounted to the wheel chair. The brackets are movably mounted
to the frame and are movable apart to a second distance less than
the maximum distance to allow mounting and unmounting of the frame
to the wheel chair. The apparatus further includes a wheel rotatably
mounted to the frame, a hand crank movably mounted to the frame,
connecting means engaged with the wheel and the hand crank and operable
to drive the wheel to move the wheel chair as the hand crank is
moved, and adjustment means on the frame and operably associated
with the brackets being operable to adjust spacing between the brackets
to change the maximum distance the brackets may be spaced apart
allowing mounting of the frame to different wheel chairs with the
frame including a first telescopically constructed rod with opposite
ends upon which the brackets are mounted and the adjustment means
including a first threaded member rotatably mounted and connected
to one of the opposite ends and a second threaded member connected
to the other of the opposite ends with the first threaded member
in meshing engagement with the second threaded member and the adjustment
means operable upon rotation of the first threaded member to change
the distance between the opposite ends.
Another embodiment of the present invention is an auxiliary drive
apparatus mountable to a wheel chair comprising an auxiliary frame
removably mountable to a wheel chair, the auxiliary frame including
a first pair of posts engaging brackets spaced apart a maximum distance
when mounted to the wheel chair, the brackets being movably mounted
to the frame and movable apart to a second distance less than the
maximum distance to allow mounting and unmounting of the frame to
the wheel chair, a wheel rotatably mounted to the frame, a hand
crank movably mounted to the frame, connecting means engaged with
the wheel and the hand crank and operable to drive the wheel to
move the wheel chair as the hand crank is moved, and the frame includes
a steering post with a proximal end pivotally mounted to the frame
and a distal end with the hand crank mounted thereon, the connecting
means includes sprocket means rotatably mounted at the proximal
end, a first continuous chain operably connected to the wheel and
the sprocket means, and a second continuous chain operably connected
to the hand crank and the sprocket means.
It is an object of the present invention to provide a new and improved
means for mounting an auxiliary drive means to a wheel chair.
A further object of the present invention is to provide a wheel
chair auxiliary drive means having a steering post accurately positioned
relative to the user's hands.
Yet another object of the present invention is to provide a new
and improved auxiliary wheel chair drive means.
Related objects and advantages of the present invention will be
apparent from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the auxiliary drive means shown mounted
to a wheel chair.
FIG. 2 is an enlarged fragmentary end view of the auxiliary frame
mounted to the wheel chair looking in the direction of arrows 2--2
of FIG. 1.
FIG. 3 is a fragmentary top view of the portion of the auxiliary
frame shown in FIG. 2.
FIG. 4 is an enlarged fragmentary top view of the steering post
looking in the direction of arrows 4--4 of FIG. 1.
FIG. 5 is an enlarged perspective view of the bearing mounting
the two chain sprockets to the top of the steering post.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For the purposes of promoting an understanding of the principles
of the invention, reference will now be made to the embodiment illustrated
in the drawings and specific language will be used to describe the
same. It will nevertheless be understood that no limitation of the
scope of the invention is thereby intended, such alterations and
further modifications in the illustrated device, and such further
applications of the principles of the invention as illustrated therein
being contemplated as would normally occur to one skilled in the
art to which the invention relates.
Referring now more particularly to FIG. 1, there is shown an auxiliary
drive apparatus 10 mounted to wheel chair. Apparatus 10 includes
a main frame 12 having a wheel 13 rotatably mounted thereto and
driven by a pair of continuous roller chains 14 and 15 engaged respectively
by sprocket mechanism 16 and hand crank 17. The rearward portion
of frame 12 is provided with a pair of clamps for removably engaging
vertically extending posts of the wheel chair.
The wheel chair includes a pair of forwardly positioned and vertically
extending posts 18 and 19 (FIG. 2) having at their bottom ends a
pair of rotatably mounted wheels 70 and 71. Four C-shaped clamps
20-23 are releasably engaged with posts 18 and 19. Clamps 20 and
21 are aligned and open outwardly being fixedly mounted respectively
to a pair of tubes 24 and 25 in turn mounted to rod 26. One end
of rod 26 is fastened by a conventional bolt 28 to tube 24 whereas
the opposite end of the rod extends freely into tube 25. Likewise,
C-shaped clamps 22 and 23 open outwardly and engage respectively
tubes 18 and 19 being fixedly mounted to a pair of aligned tubes
27 and 48 with a second rod 29 being secured to tube 27 by bolt
30 and with the opposite end of the rod extending freely into tube
48.
A pair of mutually opposed and opening tubes 31 and 32 are mounted
respectively to tubes 27 and 24 and receive and are bolted to upstanding
rod 33. Likewise, a second pair of mutually aligned and opening
tubes 34 and 35 are respectively mounted to tubes 48 and 25 and
are bolted to rod 36. A threaded rod 37 is fixedly mounted to sleeve
38 in turn fixedly mounted to tube 36. Means are provided to prevent
rotation between rod 37 and sleeve 38 with the outer end of rod
37 extending freely through a hollow cap 39 in turn mounted to tube
40 connected by means of a knee action pivot joint 41 to a second
tube 42 fixedly mounted by tube 43 to tube 33. Threaded member 37
extends freely into tube 40 and is in meshing engagement with an
internally threaded member 44 held captive in hollow cap 39. Rotation
of internally threaded member 44 causes cap 39 along with tubes
40 and 42 to move toward or away from tube 36 thereby shortening
or increasing the distance between clamps 20-21 and 22-23 to facilitate
mounting of the frame to wheel chairs having different spacing between
vertical posts 18 and 19.
Knee joint 41 is provided to facilitate the installation of the
frame to a wheel chair. When mounted, tubes 40 and 42 are aligned
and sleeve 45 extends around joint 41 preventing the joint from
bending. Sleeve 45 is slidably mounted to tube 42 and may be provided
with a helical spring to normally position the sleeve around joint
41. In order to remove the frame from the wheel chair, sleeve 45
is moved to uncover joint 41 as shown in FIG. 2 with the joint then
being pulled toward the person sitting in the wheel chair such as
shown by the dashed lines in FIG. 3. Movement of tubes 40 and 42
outwardly by bending joint 41 causes clamps 20 and 22 to move toward
clamps 21 and 23 thereby disengaging the C-shaped outer ends of
the clamps from vertical posts 18 and 19.
Frame 12 (FIG. 1) includes a front tubular housing 50 bearingly
receiving a conventional mounting post 51 having wheel 13 rotatably
mounted thereto. Post 51 extends through housing 50 having at its
top end two upwardly facing spaced apart axle seats 52 receiving
axle 56 in turn connected to rod 62 having the hand cranks 17 mounted
to the outer end thereof allowing the operator to both steer and
propel wheel 13. A pair of axle mounting members 60 and 61 are bolted
by fasteners 77 and 76 to seats 52 and have downwardly facing and
radially formed recesses to complementarily receive axle 56 allowing
axle 56 and rod 62 to pivot about the longitudinal axis of axle
56. A conventional sprocket 54 is operatively engaged with wheel
13 and is in meshing engagement with chain 14 in turn in meshing
engagement with sprocket 57 (FIG. 4) mounted to rod 56 by bearing
80 so as to turn with adjacent sprocket 55, also mounted by bearing
80, in turn in meshing engagement with continuous roller chain 15.
Hand crank 17 includes a pair of oppositely arranged handles mounted
to a sprocket 58 rotatably mounted to steering post 53 with sprocket
58 in meshing engagement with chain 15. Thus, rotation of hand crank
17 causes rotation of chain 15, sprocket 55, sprocket 57, bearing
80, chain 14, sprocket 54 and wheel 13. Bearing 80 includes a cylindrical
main body interrupted on its outer surface by three grooves 81,
82 and 83 to lockingly receive internally projecting tabs from sprockets
55 and 57 to insure rotation of sprockets 55 and 57 along with bearing
80 rotatably mounted to axle 56. Bearing 80 is mounted to axle 56
by a shoulder screw extending through internal sleeve 84 of bearing
80 and threadedly received by axle 56. Rib 85 is formed on the outer
end of bearing 80 whereas a C-shaped wire clip is removably mounted
to a groove extending around the inner end of the bearing adjacent
axle 56 limiting movement of the sprockets 55 and 57 relative to
bearing 80. Steering post 53 includes a pair of rods 62 and 63 telescopically
connected together allowing the hand cranks to be pushed towards
or away from the operator depending upon the configuration of the
wheel chair. Roller chain 15 must be shortened or lengthened in
the event the total length of the telescopic steering post 53 is
decreased or increased. In one embodiment, a multiple gear drive
mechanism is provided for wheel 13. Such a gear mechanism is conventional
in design with the shifting mechanism mounted to steering post 53.
Fixedly mounted to housing 50 are a pair of rearwardly extending
main posts 64 and 65. One end of post 64 is fixedly secured to tube
29 whereas one end of post 65 is slidably received into tube 66
secured to tube 26 and having a mounting pin 67 extending through
tube 66 and post 65 locking the post and tube together.
When installing the auxiliary drive apparatus to the wheel chair,
the clamps 20-23 are first mounted to posts 18 and 19 by pivoting
joint 41 to the outward position thereby decreasing the distance
between the clamps, then the clamps are aligned with the posts and
joint 41 is pivoted to the straight position securing the clamps
to posts 18 and 19. Sleeve 45 is then moved over joint 41 locking
the joint and clamps in the mounting position. Best results are
obtained by disengaging the wheels attached to the bottom ends of
post 18 and 19 from the ground. Thus, once clamps 20-23 are engaged
with posts 18 and 19, the wheel chair is caused to pivot slightly
on its rearward wheels thereby lifting wheels 70 and 71 (FIG. 2)
from the ground. Post 65 is provided with a series of holes through
which pin 67 may be extended. Once wheels 70 and 71 are disengaged
from the ground, pin 67 is extended through tube 66 and the particular
hole provided in post 65 which will ensure continued disengagement
of wheels 70 and 71 from the ground. One of the holes provided in
post 65 may be an elongated slot thereby eliminating the necessity
for removal of pin 67 during the initial mounting of clamps 20-23
to posts 18 and 19. As the wheel chair is pivoted, tubes 27 and
48 (FIG. 2) will be pivoted with the wheel chair with tube 29 tending
to remain stationary since the tube is fastened directly to post
64. Thus, tube 29 may be slotted to receive bolt 30 preventing undue
stress between tubes 27 and 29.
Threaded members 37 and 44 provide an adjustment means on frame
12 operable to adjust the spacing between clamps 20 and 21 and between
clamps 22 and 23. With tubes 42 and 40 aligned as shown in FIG.
2, clamps 20 and 21 will be spaced apart a maximum distance equal
to the distance between clamps 22 and 23. This maximum distance
may be changed by rotating threaded member 44 allowing mounting
of the auxiliary frame to different wheel chairs. By pivoting joint
41, the clamps may be moved apart to a distance less than the maximum
distance.
While the invention has been illustrated and described in detail
in the drawings and foregoing description, the same is to be considered
as illustrative and not restrictive in character, it being understood
that only the preferred embodiment has been shown and described
and that all changes and modifications that come within the spirit
of the invention are desired to be protected. |