Abstract:
A folding canopy for a mobility device, such as a wheelchair or scooter, can be displaced, via switch activation, from a folded position behind the backrest to the operating position above the mobility device. In the folded position, the canopy and structural members are kept behind the backrest. A press of the switch located on the armrest activates an electric motor and drives a mechanical assembly comprising of: two gears a shaft and two U-shape tubular structural members attached to weather resistant upholstery. The canopy and structural members assemble directly above the vehicle. Another press of the switch retracts the canopy.

Description:
FIELD OF INVENTION 
       [0001]    The present invention is intended for the Home Medical Equipment (HME) industry and the Durable Medical Equipment (DME) market segment. DME includes traditional devices such as walkers, crutches, canes, traction equipment, beds, bedpans, special toilet seats, lifts, cushions, pads, scooters, and wheelchairs. The present invention is an accessory tailored for mobility devices driven by electric motors, such as wheelchairs and scooters. The invention optimizes the vehicle by adding a switch activated canopy that provides weather protection and also automatically retracts into a confined space. 
       BACKGROUND OF THE INVENTION 
       [0002]    Wheelchair and scooter accessory designs that provide weather protection mainly comprise of manually mounted and operated mechanisms such as the U.S. Pat. No. 6,254,116 issued to Szumlic and Gallagher on Jul. 3, 2001. This invention comprises of a telescoping shaft with an angular disposition mechanism that allows an umbrella to be manually mounted and handled by a wheelchair-bound person. This design is adequate for a handicap person with substantial upper body mobility and function. For the handicap person who is incapable of manually inserting, opening, and maneuvering an umbrella in a shaft, a more automatic mechanism is required. 
         [0003]    Another invention that allows an umbrella to be manually inserted into a fitting and mounted on a wheelchair is U.S. Pat. No. 6,711,769, issued to Jane-Prats on Mar. 30, 2004. The invention provides the means to manually control an umbrella with a mechanism that can rotate and swivel. The invention has a mechanism that clamps onto a pillow and provides a fitting for an umbrella. The invention was initially intended for sunbathers but is currently being marketed as a wheelchair accessory. Once again, this design is adequate for a handicap or elderly person who has substantial upper body mobility and function. A person with further limitation requires automation or assistance from a secondary party. 
         [0004]    Sun protection accessories for wheelchairs and scooters also consist of manually mounted canopies, such as the U.S. Pat. No. 5,168,889 issued to Diestel on Dec. 8, 1992. This invention is a manually mounted and removable canopy that provides weather and sun protection for wheelchairs. It can also be manually dismantled and stored away in a cylindrical container. The task of manually mounting, assembling, disassembling and storing the canopy is labor intense and difficult for the average handicap person. Essentially, the assembly and disassembly requires the aid of an able-bodied person. Therefore, this invention does not promote independence amongst persons with limited upper body mobility. 
         [0005]    Protective canopies are applied to different mechanisms in a variety of industries. They also range in complexity; for example U.S. Pat. No. 5,511,259 issued to Tarrara on Apr. 30, 1996 is a simple manually driven collapsible canopy for a stretcher. This invention consists of 4 U-shaped members which are pivotally joined at the same junction point on a stretcher. The purpose of this invention is to provide privacy to hospital patients that are placed on the stretcher. A comparable complex protective canopy is U.S. Pat. No. 6,336,673 issued to Rothe, Rieste, Weissmueller, and Bramsche on Jan. 8, 2002. This invention is a convertible roof for an automobile; it consists of two separate roof sections which are relocated from a stored position within the trunk space to the roof position. 
         [0006]    Another patent is U.S. Pat. No. 5,921,258, the “Adjustable Removable Weather Shield for a Wheelchair” issued to Wade Francois on Nov. 24, 1997. This invention is a collapsible weather shield for wheelchairs; it provides a manually operated or motor activated protective canopy. The structural members relocate from behind the backrest to the operating position above the wheelchair. The flaw with this design is that it is highly conceptual and impractical. For example, the motor is directly mounted to the shaft that drives the canopy structure. This assembly is prone to mechanical failure. If the canopy is lifted, pushed, or rotated to counteract the motor&#39;s rotational force, immediate mechanical damage will occur to the motor. This is likely to happen if wind loads, human tempering or mechanical impact is applied. In addition, the canopy will be highly unstable, since the motor is the only acting braking force when the canopy is in the open or operating position and the collapsed upright position. Also, the U-shaped structural members open and retract with a spring-loaded pulley mechanism driven by the same motor. This assembly results in a highly fragile canopy. The pulley mechanism will have slack in the open position, making it prone to mechanical damage. Consequently, the spring provides an inconsistent force required to maintain the canopy structurally sound in the open position. 
         [0007]    Other impracticalities exist in various aspects of the design. For example; the required rotational speed for the canopy to open is roughly one (1) RPM, which is slower than standard motors on the market. Therefore, a non-standard motor is required, since a step down mechanism is not shown in the design. Also, the location of the motor increases the overall width, which reduces maneuverability and makes the invention prone to mechanical damage by impact. 
         [0008]    In general, the history of weather protection accessories for mobility devices such as power wheelchairs and scooters does not promote independence amongst individuals with limited abilities. The majority of mechanisms require from an able-bodied secondary party to exert a significant amount of work to operate them. The only invention that provides some form of automated weather protection is the “Adjustable Removable Weather Shield”, which presents numerous flaws and is highly conceptual and impractical. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention provides an electromechanical system designed to provide automatic sun, rain, wind and weather protection for motor driven vehicles, such as wheelchairs and scooters. The operation is best explained with a brief description of the mechanical and electrical process. In the retracted position, the structural members are joined, consequently folding the upholstery as it is kept in a confined space behind the backrest. The process begins with the single press of a switch located on the armrest. An electrical signal activates an electric motor that drives a mechanical assembly, comprised of two gears, a shaft and two tubular structural members attached to a weather resistant clothe. This sequence of events results in the linkage system relocating directly above the handicap person and wheelchair to form the structure for the upholstery and transforms into the protective canopy. If weather protection is no longer needed, another press of a switch retracts and folds the canopy behind the backrest. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is an isometric view of the canopy assembly mounted to the backrest of a wheelchair in the open position; 
           [0011]      FIG. 2  is a side view of the canopy assembly mounted to the backrest of a wheelchair in the open position; 
           [0012]      FIG. 3  is a side view of a semi-open canopy assembly that is in the process of either being opened or retracted; 
           [0013]      FIG. 4  is a side view of a canopy assembly mounted to the backrest of a wheelchair in the fully retracted position; 
           [0014]      FIG. 5  is an isometric view of a canopy assembly mounted to the backrest of a wheelchair in the fully retracted position; 
           [0015]      FIG. 6  is a rear detail view of the mechanical and structural assembly mounted to the backrest of a wheelchair in the open position; 
           [0016]      FIG. 7  is a rear close up detail view of the mechanical and structural assembly mounted to the backrest of a wheelchair in the open position; 
           [0017]      FIG. 8  is a front isometric view of the mechanical and structural assembly in the open position; 
           [0018]      FIG. 9  is a close up of the front isometric view of the mechanical and structural assembly in the open position; 
           [0019]      FIG. 10  is a close up side view of the mechanical and structural assembly mounted to the backrest of a wheelchair in the open position; and 
           [0020]      FIG. 11  is an alternate embodiment with 3 ribs, isometric view of the canopy assembly mounted to the backrest of a wheelchair in the open position. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    For purpose of understanding the invention, reference will now be made to embodiments illustrated in the drawings. Whenever in general the open position or operational position is mentioned, refer to  FIGS. 1 and 2 . If the canopy assembly is being described as in the process of either being opening or retracting refer to  FIG. 3 . The generally described retracted position is shown in  FIGS. 4 and 5 . Refer to  FIGS. 6 ,  7 ,  8 ,  9 , and  10  for specific component references.  FIG. 11  illustrates an alternate embodiment. 
         [0022]    The whole operation of the canopy assembly is controlled by the user with a switch  38 . In an exemplary model this is a three-way push switch, mounted at the wheelchair arm rest, and it is either in the open, neutral, or retract position. The three-way switch allows for the canopy operation to be stopped at any position during operation with the option to then open or retract the canopy assembly after it has been stopped. This gives the user the ability to stop the operation of the canopy at any time and then either continue in the same direction or reverse back. 
         [0023]    The entire mechanism is mounted to the main mount bracket  16 . In an exemplary embodiment, all the mechanical, electrical and structural components are mounted to the main mount bracket  16 . This configuration allows simple and fast installation of the canopy assembly to the wheelchair backrest  15 . Bolts attach the main mount bracket  16  to the backrest  15 . 
         [0024]    In an exemplary embodiment, the main mount bracket  16  mounting hardware  1  and  19  is specific to one kind of wheelchair with rails on the seat backrest  15 . In general the main mount bracket  16  can be configured to mount to a different variety of wheelchairs, scooters or any other vehicles with a combination of specific or adjustable bolts, clamps or brackets. 
         [0025]    The motor  7  is mounted to the main mount bracket  16  by the motor mount plate  17  and the motor mount block  20 . In an exemplary embodiment the motor  16  is a gear motor with a low RPM and high torque. Referring to  FIG. 8 , the gear motor  7  provides rotational force about the vertical axis and transfers it, with the use of a coupling  4  and worm shaft  8 , to a worm  11 . The worm  11 , coupling  4 , and worm shaft  8  assembly remains structurally sound because of the mounted bearing  13 , which is bolted to the main mount bracket  16 . A collar  18  that connects to the worm shaft  8  also provides structural support and alignment for the worm  11  and coupling  4  assembly. The worm  11  transfers a rotational force to the worm gear  12  and the main shaft  9  and changes the force to the rotational motion along the horizontal axis. The main shaft  9  is held in place by the main mounted bearings  13 , which connect to the main bracket  16 . The collars  18  provide lateral alignment for the main shaft  9 , worm gear  12 , main mounted bearings  13  and limiter mount brackets  24 . Referring to  FIG. 7 , the limiter bolts  10  and  14  are attached to the main shaft  9  through the limiter mount brackets  24 . 
         [0026]    Referring to  FIG. 8 , the canopy assembly consists of two (2) unshaped tube ribs  3  and  5  attached to the main shaft  9 . The upholstery  22  is attached to the structural members  3  and  5 . The upholstery material  22  is vinyl in an exemplary embodiment but the upholstery  22  can be made out of any material that will satisfy these requirements: Water resistant if the canopy will be used for rain protection, ability to block the sun for sun protection, flexible and strong enough to withstand pulling and folding during operation. 
         [0027]    Rib  15  is attached to the main shaft  9  through the rod end  130  and it is pinned to the main shaft  9  by a quick release safety pin  29  constraining the movement to be dependent to the rotation of the main shaft  9 . The purpose of the quick release safety pin  29  is to be a safety device allowing manual canopy operation in case of a battery, motor or gear(s) malfunction. When the quick release pin  29  is pulled out, it allows free movement of rib  15  by removing a rigid connection between the rod end  130  and the main shaft  9 . Rib  23  is attached to the main shaft through rod end  22  and is allowed is rotate freely about the horizontal axis independent of the main shaft  9  rotation. Plain bearing  6  reduces friction between the rod end  22  and the main shaft  9 . 
         [0028]    The basic operation of the canopy assembly will now be described. The electrical power to the control switch  38  and motor  7  is provided from the wheelchair batteries. In an exemplary embodiment, a power wheelchair is used that already has a battery system onboard. If the vehicle does not have its own battery system, an add-on battery pack can be installed. When the gear motor  7  is engaged by the control switch  38  at the arm rest to open the canopy, the motor  7  and main shaft  9  turn forward and the main shaft  9  lifts rib  15  from the retracted position to the open position. Rib  15  pulls the canopy material  22  and the canopy material  22  pulls rib  23  to the open position. When the canopy assembly is close to being in the fully open position, the rib  23  comes in contact with the extend stop  31 . This locks rib  23  in the vertical position and constrains any further forward movement. Rib  15  continues to rotate and it pulls all the slack out of the canopy material  22  until the open position limit switch  23  is engaged by the open position limiter bolt  14 . That cuts the forward direction power off from the motor  7  and locks the canopy assembly in the open position. The “one way” property of worm gears, e.g., worm  11  and worm gear  12 , locks the canopy assembly and prevents any unintended movement of the assembly when the gear motor  7  is not operating. 
         [0029]    When the control switch  38  is pushed to retract and engages the motor  7  to turn in the reverse direction, the main shaft  9  turns the rib  15  again but now in the retracting direction. As the rib  15  starts to turn the first thing that happens is tension in the canopy material  22  is released. As the rib  15  continues to rotate back, it pushes back the canopy material  22 . Then the canopy material  22  pushes rib  23  back to the retracted position. Rib  23  rotates until it comes in contact with the retract stop  32 . Retract stop  32  prevents rib  23  from moving any further back. As rib  15  continues to move back, it compresses the canopy material  22  until the retracted position limit switch  21  is activated by the retracted position limiter bolt  10  which in turn cuts off the power to the gear motor  7  in the reverse direction. The limiter lock nuts  25  and limit switches  21 ,  23  combination allow manual adjustment of when the limit switches  21 ,  23  are engaged in both the extended and retracted position. This allows the final position in the fully open and retracted position of rib  15  to be adjustable. 
         [0030]    In the combination of all the components described above creates a canopy mechanical and structural assembly that is compact and simple. The combination of mechanical drive-train components and positioning of those components such as the motor  7 , worm  11 , worm gear  12  and mating to the main shaft  9  creates a compact drive-train that does not create any significant obstructions. In an exemplary embodiment, the gear motor  7  rotates at 25 revolutions per minute and then worm  11  and worm gear  12  reduce the rotational speed by a factor of 20 so that the main shaft rotates at approximately 1.25 RPM. The motor and gears combination result in the canopy movement from the retracted to open position and vice versa to last around thirty (30) seconds. This speed of operation creates the right balance of motion. If the ribs  3 ,  5  along with the canopy material  22  were to move too fast, a potentially unsafe situation could be created. On the other hand, if the operation takes too long, that would create an inconvenience for the user. 
         [0031]    A safety system can be added to stop all moving parts in case of a mechanical jam or an obstruction, such as clothing or a body part, encountered during operation. To accomplish that a potentiometer and a motor controller can be added to the motor&#39;s  7  circuit that will detect excessive electrical current draw during operation and will prevent any further movement and will either stay stopped or back off the opposite way. 
         [0032]    In an exemplary embodiment, the combination of the ribs  3 ,  5  and rod ends  2  and  30  that provide mounting to the main shaft  9  allow the canopy assembly to fit within the footprint of the wheelchair. This is a useful feature as the canopy assembly is not wider than the wheelchair itself and the wheelchair can still fit through tight spaces such as doors and narrow hallways. At the same time user space is maximized as the ribs  3 ,  5  and canopy material  22  shall not interfere with the person sitting in the chair. Also, ribs  3  and  5  are made out of hollow aluminum tubing that is light and flexible when excessive load is applied. As a result, when heavy wind gusts are experienced, the ribs  3  and  5  will tend to flex therefore absorbing the wind forces that might otherwise flip the wheelchair over to the side. To further reduce the wind drag forces, the canopy material  22  side and back sections can be made out of material that lets the air through such as a mesh material. 
       DESCRIPTION OF ALTERNATE EMBODIMENT 
       [0033]    An alternate version of the invention is a similar design, in which instead of utilizing two (2) rib assemblies  2 ,  5  there can be three (3) rib assemblies. Refer to  FIG. 11 . As far as the mechanical system is concerned, the only difference would be the additional third middle rib and associated hardware. The additional rib  3  would function as a structural member only, allowing rib  15  to extend further to the front. The advantage of 3 rib design is greater front protection against sun and rain. The disadvantage is a more complicated design and limiting of front and side visibility. Any canopy material  22  that is directly in the front and to the side of a user would have to be transparent.