Adjustable removable weather shield for a wheelchair

A detachable and collapsible weather shield for a wheelchair may be user-disposed in a user-selected orientation. The weather shield includes first and second generally inverted "U"-shaped frames, in which the distal leg ends of the second frame are pivotally joined by a coupler to a leg portion of the legs of the first frame. A flexible moisture resistant canopy extends over at least the top portion of the frames and preferably also extends downward to also cover a portion of the legs. A releasable pivotable anchor is secured to one and preferably both wheelchair push arm regions, and permits releasably and rotatably attaching the distal leg ends of the first frame to the wheelchair. The anchor permits user-adjustment of the relative angular orientation of the first frame (and thus of the weather shield) and/or the vertical height (including complete removal) of the weather shield relative to the ground. The anchor unit may be manually operable, or may be motorized. If motorized, user-generated control signals may be wirelessly transmitted to a receiver associated with the motor, or hardwiring may be provided.

FIELD OF THE INVENTION 
The present invention relates generally to wheelchairs and apparatus to 
shield a wheelchair user from rain and sun, and more particularly to such 
apparatuses as are user adjustable and removable. 
BACKGROUND OF THE INVENTION 
Wheelchair users are often exposed to inclement weather including rain, 
fog, wind, and/or excessively sunny weather while occupying a wheelchair. 
If the wheelchair is manually propelled, the user's hands are occupied and 
are not free to hold an umbrella or the like to protect the user in 
inclement weather. Even if the wheelchair is motorized, the user is often 
occupied in maneuvering the wheelchair. Also, some wheelchair users simply 
lack arm strength to hold an umbrella or the like in inclement weather. 
Several attempts have been made in the prior art to try to protect 
wheelchair users from inclement weather. For example, U.S. Pat. No. 
4,389,057 to Spence, Jr. (1983) discloses a transparent wheelchair cover 
comprising a number of clear panels removably attached to the front of the 
wheelchair. The cover is supported by a frame having a pair of 
substantially vertical members joined at the top by a horizontal member. 
When deployed, Spence's cover appears to have been locked in a static 
position, as though incoming rain or sunshine always fell perpendicularly 
to the ground. U.S. Pat. No. 4,949,740 to Friday (1990) discloses a 
transparent rain hood apparatus for wheelchair users. Friday provides a 
symmetrical collapsible tubular structure removably attached to the 
wheelchair undercarriage, and topped by a plastic covering. The support 
frame includes a rectangular shaped portion of four tubular members 
hingedly joined at two front and two rear corners. Like Spence's device, 
the device disclosed by Friday appears to assume that rain and sunshine 
will fall perpendicularly to the ground. 
U.S. Pat. No. 4,643,479 to Servi (1987) discloses a wheelchair canopy shade 
having a frame mountable to the handle grips of the wheelchair. The frame 
includes at least two vertically disposed posts that are braced by at 
least one transverse member. Roof-forming members are connected to the top 
ends of the two vertically disposed posts, and a vinyl or canvas parasol 
shade snaps on to the frame. However, Servi's vertical members appear to 
be static vertical, although the roof portion seems pivotable rearward 
toward the vertical posts. 
U.S. Pat. No. 5,168,889 to Diestel (1992) discloses a wheelchair removable 
weather breaker cover that is removably secured by a cover support clamp 
bracket. A tubular extension may be fitted to the clamping bracket to 
promote stability of Diestel's wheelchair cover. The cover is attached by 
two short tubular members that releaseably clamp to vertical posts that 
are positioned adjacent the wheelchair handles. Not unlike several of the 
prior art designed described above, Diestel's structure is essentially 
disposed statically horizontally and vertically. Unfortunately, such 
static structure does not permit varying the cover orientation should rain 
or sunshine fall other than perpendicularly to the ground. 
Thus, there is a need for an adjustable wheelchair shield that can be 
oriented in other than a purely horizontal-vertical configuration. Such 
shield should be user adjustable with respect to orientation, and 
preferably should be collapsible so as to not require removal from the 
wheelchair when not in use. Such shield should, however, be readily 
removable. Further, such shield should be mechanically reconfigurable for 
use by wheelchair users who lack sufficient arm strength to manually 
adjust the shield. Finally, to promote wide spread use of such a shield, 
the shield should be readily and economically manufacturable. 
The present invention provides such a wheelchair shield. 
SUMMARY OF THE INVENTION 
The present invention provides a detachable and collapsible weather shield 
for a wheelchair that may be user-disposed in a user-selected orientation. 
The weather shield includes first and second generally inverted "U"-shaped 
frames, in which the distal leg ends of the second frame are pivotally 
joined by a coupler to a leg portion of the legs of the first frame. A 
flexible moisture resistant canopy extends over at least the top portion 
of the frames and preferably also extends downward to also cover a portion 
of the legs. The spaced-apart width of the frames is substantially the 
spaced-apart distance between the push arm portions of the wheel chair. 
A releasable pivotable anchor is secured to one and preferably both 
wheelchair push arm regions, and permits attaching the distal leg ends of 
the first frame to the wheelchair. The anchor permits user-adjustment of 
the relative angular orientation of the first frame (and thus of the 
weather shield) and/or the vertical height of the weather shield relative 
to the ground. The anchor unit may be manually operable, or may be 
motorized. If motorized, user-generated control signals may be wirelessly 
transmitted to a receiver associated with the motor, or hardwiring may be 
provided. 
User-adjustment of the anchor permits orienting the canopy to a desired 
height and angle to shield against rain, wind, sun, and the like. The user 
may also collapse the second frame into the first frame, thus folding the 
canopy, and then rotate the first frame rearward 180.degree. to store the 
weather shield in a vertical downward orientation, just behind the 
wheelchair seat. Of course, the user may simply remove the first frame 
from the anchor(s) to remove the weather shield from the wheelchair.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1A depicts a generic wheelchair 10 whose left and right handle push 
arm portions 20 provide removable attachment for an detachable adjustable 
weather shield 30, according to a first embodiment of the present 
invention. Weather shield 30 includes a flexible and preferably water 
resistant canopy or tarpaulin 40 that is supported by first and second 
inverted "U"-shaped frame members 50 and 60 (see also FIGS. 2A and 2B). 
Canopy 40 may be a plastic material and preferably removably attaches to 
the framework provided by frame members 50 and 60 with snaps or the like 
(not illustrated). Members 50 and 60 preferably are a lightweight material 
such as metal, e.g., aluminum, plastic, fiberglass, epoxy, among other 
materials. 
As shown, the distal end of the two legs of second frame member 60 are 
rotatably secured to a portion of two legs of first frame member 50 by a 
coupling unit 70. The lower portion of first frame member 50 exits 
coupling unit 70, continuing downward. The distal ends 80 of first frame 
member 50 are releasably clamped by an anchor unit 90 that preferably is 
mounted to the push arm portions 20 of the wheelchair. Preferably one 
anchor unit 90 is located near the right push arm portion of the 
wheelchair, and another anchor unit is located near the left push arm 
portion. While two anchor units 90 are preferred for stability and 
strength, it is possible to implement the present invention with a single 
adjustable anchor unit 90. In such a configuration, a passive member would 
loosely capture the distal end 80 of frame member 50 on the other push arm 
side of the wheelchair. 
An exemplary anchor unit 90 is described later herein with respect to FIGS. 
3A and 3B. In the embodiment of FIGS. 1A and 3A, anchor unit 90 is 
manually adjusted, for example with a lever 100. Operation of lever 100 is 
somewhat analogous to operation of a lever on a quick-release type 
mechanism such as may be found on a mountain bicycle. By contrast the 
embodiment of FIGS. 1B and 3B depict an anchor unit 90 that is adjusted 
with a motor. 
As noted, members 50 and 60 are rotatably coupled via coupler 70. Thus, 
FIG. 1A depicts member 50 angled completely forward through an angle 
.PHI.1 of perhaps 60.degree., and in phantom lines member 50 is shown at a 
lesser angle .PHI.1'. Note that as angle .PHI.1 decreases toward 
0.degree., flexible canopy 40 essentially folds up. Unit 70 may be 
implemented with rotation detentes that permit angular orientation every 
10.degree. for example, or may provide a frictional control permitting 
essentially continuous change in angle .PHI.1. 
In addition to permitting the extent of canopy 40 to be controlled by 
rotating member 60 relative to member 50, the user can also rotate the 
entire weather shield 30. Thus, in FIG. 1B, the angle .theta.1 defined 
between the horizon and the vertical orientation of the weather shield is 
shown as being varied from .theta.1 to .theta.1'. Such adjustment is made 
by the user loosening anchor 90 such that first frame member 50 can be 
rotated through various angles .theta.1. Of course, the user may 
simultaneously vary angle .PHI.1 and angle .theta.1. Indeed, as shown by 
FIGS. 1C and 1D, angle .PHI.1 may be user adjusted to essentially 
0.degree. and angle .theta.1 may be user adjusted to essentially 
-90.degree.. Further, FIG. 1C depicts a change in vertical adjustment 
(shown in phantom lines) of the weather shield, relative to the push arm 
regions of the wheelchair. If desired, the weather shield could be removed 
from the anchor unit, as described with respect to FIG. 3A, later herein. 
The -90.degree. configuration shown in FIG. 1D represents stowing the 
weather shield while leaving it attached to the wheelchair. 
It will be appreciated from FIGS. 1A and 1B that the user can bring about 
different weather shield orientations. For example, if the sun were 
directly overhead, or if it were raining essentially vertically, the 
orientation of FIG. 1A might be beneficial. However, if the sun or wind or 
rain were originating from behind the wheelchair, the orientations 
indicated by FIG. 1B would be more useful. This flexibility in orienting 
the weather shield is in contrast to what can readily be changed in prior 
art devices. 
The embodiment of FIG. 1B recognizes that not all wheelchair users may have 
sufficient arm strength or mobility to manually adjust mechanism(s) 90 
with levers 100 (or other mechanical devices). Accordingly, the embodiment 
of FIG. 1B provides a motor 110 whose power supply may be an on-wheel 
chair battery (shown in FIG. 1B as BATT), perhaps the battery that may be 
present to power a motorized wheelchair 10. It will be appreciated that 
the orientations shown in FIGS. 1A, 1C, 1D may also result from user 
adjustment made with a motor 110 to operate each anchor mechanism 90. 
Motor 100 may be hardwired (wiring not shown) to a controller unit 120 
conveniently disposed, perhaps near the arm rest portion of the wheel 
chair. Such controllers could be operated by moving a joystick, by 
pressing one or more buttons, by beaming light upon a sensor, even with 
user voice command, if desired. If desired, hardwiring could be eliminated 
by providing controller 120 with a short range transmitter 130, and by 
providing motor 110 with a receiver 140. Transmitter-receiver 130-140 may 
operate with radio frequencies, optical frequencies including infrared, 
and/or acoustic frequencies. Low sensitivity transmission-reception is 
preferred to avoid extraneous signals controlling motor 110, and thus from 
undesirably reorienting weather shield 30. 
FIGS. 2A and 2B depict views of canopy 40 and supporting frame members 50, 
60 viewed along the section line 22 indicated in FIG. 1A. Note in the 
motorized embodiment of FIG. 2B, it is unnecessary that a receiver 140 be 
associated with each motor 110. Thus, if the right-side motor 110 is 
associated with a single receiver 140, control signals from receiver 140 
can also command operation of the left-side motor as well. 
FIG. 3A is an end view of an exemplary anchor unit 90 that is manually 
operated using lever 100. By contrast, the embodiment of FIG. 3B depicts a 
motorized anchor unit 90. 
As shown in FIG. 3A, anchor unit 90 includes a two legged clampable member 
200 that defines a through opening 210 sized to surround a portion of the 
push arm region 20 of wheelchair 10. Understandably, if a cross-section of 
the push arm region 20 is other than circular, then opening 210 will 
preferably be similarly shaped. A shaft 220 passes through both legs of 
member 200, and is secured at one end by a bolt or wingnut 230 and at the 
other end by a clamp unit 240. 
Clamp unit 240 can act to compress the legs of member 200 such that opening 
210 is reduced in cross-section to securely anchor mechanism 90 to the 
push arm region 30 of wheelchair 10. Thus, one function of clamp unit 240 
is to controllable clamp and secure anchor mechanism 90 to wheelchair 10. 
Further, clamp unit 240 secures the distal end 80 of first frame member 
50, to attach the present invention to anchor unit 90, and thus to 
wheelchair 10. More particularly, anchor unit 90 includes a frame rod 
retaining member 270 that includes a through opening 280 sized to admit 
the distal end 80 of first frame unit 50. Thus, a second function of clamp 
unit 240 is to controllably clamp the distal end of the first frame member 
to anchor unit 90 (and thus to the wheelchair), so as to permit user 
vertical adjustment relative to the height of the wheelchair push arm 
region. 
Note in FIG. 3A that the outer leg portions of member 200 preferably 
include friction surfaces 250. These friction surfaces can frictionally 
engage facing friction surfaces 260 associated with distal portion 80 of 
first frame member 50, and with a facing portion of clamp unit 240. 
Thus, if mechanism 240 is sufficiently loosened, angular rotation of 
weather shield 30 from anchor unit 90 may be accomplished. More 
specifically, in FIG. 3A if unit 240 is loosened, e.g., by rotation of 
lever 100, or by loosening nut 230, it becomes possible to rotate first 
frame 50 about the axis of shaft 220, to produce the angular rotation 
.theta.1 indicated in FIGS. 1B-1D. Thus, a third function of anchor unit 
90 is to permit user adjustment of the angular orientation of the weather 
shield, e.g., to an angle .theta.1 most suitable to shield against 
incoming rain, sun, wind, etc. In a minimal compression or friction 
condition, unit 90 permits sliding distal end 80 of first member 50 up, 
down, or through opening 280 in member 260. Such vertical re-positioning 
is shown in phantom in FIG. 3A, and by the double vertical arrows at the 
bottom of the figure. 
In the embodiment of FIG. 3B, controllably energizing motor 110 (e.g., 
under wired or wireless control from a controller/transmitter 120/130) can 
similarly vary compression exerted by member 200 upon the push arm region 
30, and can vary friction between first frame member 50 and anchor unit 
90. For example, motor rotation in one direction can reduce compression 
slightly, permitting the above noted angular orientation through various 
angles .theta.1. In a slightly reduced compression state the opposing 
frictional surfaces 250, 260 can rotate relative to one another, to define 
a user-selected angle .theta.1. Once a desired angle is attained, 
controller/transmitter 120/130 causes motor rotation in the opposite 
direction, whereupon anchor unit 90 re-compresses, the lock the present 
configuration. In the embodiment of FIG. 3A, rotating lever 100 (or 
equivalent) facilitates reduction and increase of compression to permit 
varying angular rotation .theta.1, as well as vertical adjustment of the 
weather shield. 
It will be appreciated that motor 110 could also cause folding of canopy 40 
as depicted in FIG. 1A. For example, as shown in FIG. 1B, a spring 300 or 
the like disposed between frame members 50 and 60 could normally bias the 
frame members apart, fully opening canopy 40 as shown in FIGS. 1A and 1B. 
Cables 310 from the left and right sides of frame members 60 could 
traverse left and right pulleys 320 mounted on frame member 50 such that 
the cables then travelled downward, parallel to frame member 50. A cog 
rotatable by motor 110 could then "wind in" the cables, essentially 
producing the decrease in angle .PHI.1 shown in FIG. 1A. When the motor 
110 (or a clutch mechanism or the like) releases the wound in cable, the 
normal expansion bias from spring 300 would fully deploy canopy 40, as 
shown in FIG. 1B. 
Modifications and variations may be made to the disclosed embodiments 
without departing from the subject and spirit of the invention as defined 
by the following claims.