Pump type wheelchair and conversion kit

Abstract

A pumped wheelchair includes one or more pump arms. Driving wheels are arranged on each side of the wheelchair. The pump boom is connected to two drive mechanisms which are connected to a drive shaft for driving the wheels. The handle lever may be connected to the pump boom. The handle lever may be lowered to allow an operator to sit in a wheelchair more easily and then raised to an operating position prior to performing a pumping action. In response to rotation of the handle lever, different forces may be applied by the drive mechanism to the drive wheels to steer the wheelchair. A reversing mechanism may be provided to reverse the wheelchair. The conversion kit can convert a traditional wheelchair into a pumping wheelchair. The footrest may be connected to the pump arm to move forward and rearward in response to a pumping action.

Description

[0001] Cross Reference to Related Applications

[0002] This application is a PCT application of and claims priority to U.S. Patent Application Serial No. 18 / 369,494, filed September 18, 2023, the contents of which are incorporated herein in their entirety by this reference. TECHNICAL FIELD

[0003] The present invention relates generally to motorized vehicles. More particularly, the present invention is primarily concerned with motorized vehicles, such as wheelchairs and the like, that are specifically designed to provide enhanced mobility and therapy for the handicapped. BACKGROUND

[0004] The Applicant is the inventor of U.S. Patent Nos. 5,829,772; 6,179,314; 6,932,370; 10,479,439; and 11,447,204, which are related to pump-action vehicles, the contents of each of which are incorporated herein in their entirety by this reference. Pump-action vehicles have been used as toys for children as well as therapeutic devices for handicapped (including learning or developmental handicapped) children and adults. Such devices have also been proposed for use as transport devices for adults.

[0005] Conventional, manually operated wheelchairs, such as Figure 1 and Figure 2 the depicted wheelchair, require the placement of a hand on or near the dirty drive wheels to propel the wheelchair forward or in reverse. These large, manually operated drive wheels are cumbersome and difficult to operate for many people. Electrically powered wheelchairs do not provide exercise for the operator. In addition, conventional wheelchairs do not provide a mechanism for exercising the legs of the individual while operating.

[0006] It is desirable to provide a pump-action wheelchair that allows movement based on simple arm movements and provides enhanced convenience, comfort, accessibility, and therapeutic movement for the user of the wheelchair, including the handicapped. It is also desirable to have a kit for converting a conventional wheelchair to a pump-action wheelchair. SUMMARY

[0007] In accordance with various embodiments and principles of the present inventive concepts, a pump-action wheelchair can be provided that has numerous improvements over the related art, such as including a smaller footprint and a smaller turning radius, as well as an improved drive system and increased rehabilitative advantages. The pump-action wheelchair can also be easily transportable.

[0008] In particular, the principles of the inventive concept provide a pump-action wheelchair that can be driven using simple arm movements, such as a pump action or a rowing action. For example, a pump (or pump-action) arm can be provided that propels the vehicle through a simple pump action. The pump arm can include a handlebar that can be lowered for the operator to sit into the chair and subsequently raised to an operating position to allow pumping. Alternatively, row (or rowing) arms can be provided along both sides of the wheelchair that propel the vehicle based on a simple rowing action. Motors can also be provided to provide assisted power. The front wheels can be similar to the front wheels of a conventional wheelchair and can be free to pivot to move in the direction of drive.

[0009] The pump-action wheelchair according to the principles of the inventive concept can further include one or more footrests that engage the operator's feet and move forward and backward during operation of the pump arm or rowing arm. For example, the footrests can be mounted on struts, bars (or other mechanical links) that are connected to the pump arm. Stops or limiters can be provided to limit the forward and backward movement of the footrests.

[0010] In one embodiment, a footrest is disposed on each side of the wheelchair to accommodate each foot of the operator. Each footrest is preferably connected to the pump arm by a mechanical link, such as an arm, bar, strut, or other transfer link. When the pump arm is actuated, each of the footrests moves forward and backward in opposition to the movement of the handlebar. More specifically, when the handlebar is pulled back (or toward the operator), the footrests move forward. When the handlebar is pushed forward (away from the operator), the footrests move backward. Alternatively, one footrest can accommodate both feet of the user.

[0011] The footrests have one or more guards that help keep the operator's feet in place within the footrests during operation. The guards can be, for example, raised edges of the footrests themselves or other attached ridges or structures to prevent the operator's feet from slipping out of the footrests. During operation of the wheelchair, the operator's feet can be moved forward and backward with the footrests connected to the pump or rowing arms and provide rehabilitative exercise for the operator's legs.

[0012] The operator can also use their leg muscles to move the footrests to assist the pump action. The footrests can include treads and / or friction surfaces that help maintain traction between the operator's feet and the footrests. For example, treads can be formed directly on the footrests or rubber or other gripping surfaces can be provided on top of the footrests.

[0013] In embodiments having two paddle arms instead of a single pump arm, two independent footrests can be provided and independently connected to individual ones of the paddle arms. In this embodiment, the footrests can move forward and backward in opposition to the movement of the respective paddle arms.

[0014] The pump or paddle arms can further be connected to a drive mechanism of the wheelchair, which is arranged in communication with the drive wheels. In one embodiment, each drive wheel includes a separate drive mechanism. Each drive mechanism can include a drive shaft connected to a drive wheel that is selectively driven based on the orientation and pumping action of the handlebar (or other steering control mechanism). The drive mechanisms can each be configured to selectively operate in forward and reverse directions.

[0015] In one embodiment, to steer the wheelchair, a steering mechanism can be provided to the pump arm to selectively engage and disengage the drive mechanisms based on the orientation of the handlebar, steering wheel, or other steering control mechanism. More specifically, in this embodiment, when the handlebar is straight, the drive mechanisms for both drive wheels are driven in the forward direction due to the pumping action. When the handlebar is turned slightly to the right, the drive mechanism for the left wheel is engaged to drive the left wheel forward, while the drive mechanism for the right wheel is disengaged so that the right wheel is not driven forward. In this manner, the wheelchair can be steered to the right. When the handlebar is sharply turned to the right, the drive mechanism for the left wheel is engaged to drive the left wheel forward, and the drive mechanism for the right wheel is engaged in the reverse direction to drive the right wheel backward, thus causing the wheelchair to make a sharp right turn or spin to the right. Alternatively, the right wheel can remain stationary during the right turn action.

[0016] Similarly, when the handlebar is turned slightly to the left, the drive mechanism for the right wheel is engaged to drive the right wheel forward, while the drive mechanism for the left wheel is disengaged so that the left wheel is not driven forward. In this manner, the wheelchair can be steered to the left. When the handlebar is sharply turned to the left, the drive mechanism for the right wheel is engaged to drive the right wheel forward, and the drive mechanism for the left wheel is engaged in the reverse direction to drive the left wheel backward, thus causing the wheelchair to make a sharp left turn or spin to the left. Alternatively, the left wheel can remain stationary during the left turn action.

[0017] In alternative embodiments, the orientation of the steering control mechanism can determine the degree of driving of the individual drive mechanisms by the pumping action. For example, a gear or other force control device (not shown) can be used to control the amount of pumping force that drives the drive mechanisms based on the orientation of the handlebar. When the handlebar is straight, equal force can be applied by each drive mechanism. When the handlebar is rotated, a proportional force can be applied to the appropriate drive mechanism based on the degree of rotation, such that a more sharp rotation of the handlebar produces a more sharp turn, while a lesser rotation produces a more gradual turn.

[0018] In embodiments of the rowing (rower) arms, steering can be provided by selective operation of the rowing arms. Each rowing arm can independently control one of the drive mechanisms. Operating one rowing arm without the other, or operating one rowing arm more forcefully than the other, can cause the wheelchair to turn in the direction away from the rowing arm that is operated more forcefully.

[0019] The pumping arm can further include a lever or other actuator, such as a squeeze lever, that reverses the direction of drive of the wheelchair. When the lever is pulled, the pumping action drives the drive mechanisms and connected wheels in the reverse direction. As the lever is pulled, the steering operation described above is also reversed.

[0020] Each of the drive mechanisms can include a drive belt that travels in a loop around two wheels. Of course, the belt and wheels can be readily replaced with a chain and sprocket, or with a rope or cable and pulley, gears or wheels, or other drive mechanisms. The drive mechanisms can be arranged substantially horizontally, with the first idler wheel arranged toward the front (or rear) of the wheelchair. The second drive wheel is fixedly attached to the drive axle to force the drive axle to rotate in the direction of rotation of the drive wheel. Alternatively, the drive mechanisms can be arranged substantially vertically, with the idler wheel arranged above (or below) the drive wheel.

[0021] A drive assembly can be arranged above the belt and moves forward and backward in response to the action of the pumping arm. The drive assembly can include a base, a bracket, and a drive member, such as a latch, pivotally mounted in the bracket. The drive latch can be spring biased into a forward drive position, or it can be activated into the forward drive position by a squeeze lever on the handle or other mechanism or any other mechanical or electrical assisted activation device.

[0022] In the forward drive position, the first engagement end of the drive latch engages the teeth in the belt. The first engagement end of the latch is designed to engage the teeth of the belt when moving in the first (forward) direction, and to slide past the teeth without engaging when moving in the opposite second direction. In this way, when the drive mechanism moves forward in response to the pumping action, the first engagement end of the latch engages the teeth of the belt to drive the belt forward. As it does so, the drive wheel is driven forward, also driving the axle (together with the connected drive wheels) in the forward direction. Thus, the wheelchair is driven forward in response to the movement of the pumping arm assembly.

[0023] A reverse mechanism can also be provided, enabling operation in a reverse direction. The reverse mechanism can operate by pivoting the drive member into a reverse position against the force provided by the spring. This can be achieved, for example, using a squeeze handle arranged on the handlebar, or by using some other lever or switch that can be connected to the drive mechanism by a cable. When the reverse mechanism is actuated, the drive member (latch) is pivoted so that the opposite, second engagement end of the drive member engages the belt. The second engagement end of the drive member is configured to engage the teeth of the belt when moving in the rearward direction, while sliding freely without engaging the belt when moving in the forward direction. In this way, with the reverse mechanism engaged, the drive mechanism engages and drives the belt in the rearward direction, causing the drive wheels, axle and drive wheels to move in the reverse direction. The wheelchair is thus driven backwards in response to a pumping action.

[0024] Alternatively, the drive mechanism can be configured to engage the drive belt, chain, rope, gears, etc. in the appropriate direction during forward and rearward movement of the pumping arm, to drive the wheelchair in the desired direction during the pushing and pulling action of the pumping arm.

[0025] In an alternative embodiment, two drive assemblies can be provided to drive each belt or chain. This embodiment can be useful, for example, when using a draw arm instead of a pumping arm.

[0026] The drive wheels can each comprise an inflatable tire having a tread pattern designed to engage the ground and provide sufficient grip for the vehicle to move over any terrain.

[0027] The wheelchair can be collapsible for transport or storage. More specifically, the wheelchair can be capable of being collapsed in a manner similar to a conventional wheelchair, with the additional pumping components designed to collapse with the wheelchair.

[0028] According to yet another embodiment, a conversion kit can be provided to convert a conventional, manually driven wheelchair or other wheelchair into a pumping wheelchair. In one embodiment, the conversion kit can be designed to be secured to a conventional wheelchair at one or more anchor points using a clamping system or other connection mechanism.

[0029] For example, the conversion kit can be designed to connect to a conventional wheelchair at three (or more) points along each side of the wheelchair frame, using clamps or other connection mechanisms. These connection points can be common to many, if not all, conventional, manually driven wheelchairs. The conversion kit can be a universal conversion kit designed to convert any type of conventional wheelchair into a pumping wheelchair.

[0030] In one embodiment, the wheels of a conventional wheelchair are removed and then reattached to drive shafts on a conversion kit. The conversion kit provides one or more pump-action arms that are connected to the drive shafts by a drive mechanism to propel the wheels in response to the pump-action arms. The drive mechanism can drive movement of the drive shafts and connected wheels in response to forward and backward movement of the pump-action arms or in response to movement of the pump-action arms in a forward or backward direction. A steering mechanism can be provided to selectively drive the left and right drive shafts in a desired amount by responding to turning of a steering handle to turn the wheelchair. A reverse mechanism can also be provided to allow pump-action to reverse drive the wheelchair when the reverse mechanism is activated.

[0031] In another embodiment, a small electric motor can be provided as an assist mechanism to help propel the wheelchair. In one embodiment, one or more sensors can be provided that sense resistance when an operator attempts to operate the pump-action arms and propel the wheelchair. If a significant amount of resistance is detected, such as on a hill or for a user with less arm activity or strength, the sensors can detect this and engage the electric motor. The electric motor is preferably connected to the drive shafts to provide an assist drive force to the vehicle when needed. The electric motor can also be controllable to drive the shafts in a forward or reverse direction and thereby provide differential force to the drive shafts to turn the wheelchair based on rotation of the handlebar.

[0032] A user-selectable switch or other user-selectable control can be provided to enable the user to select the amount of assist force from the electric motor that is desired. For example, the user can select to operate the vehicle completely manually or the user can select up to a maximum amount of assist from the electric motor. Preferably, the switch or other user-selectable control allows a wide range of selection between minimum assist and maximum assist.

[0033] Various aspects, embodiments and configurations of the present inventive concept are possible. Therefore, the present inventive concept is not limited to any specific aspect, embodiment or configuration disclosed herein. BRIEF DESCRIPTION OF DRAWINGS

[0034] The foregoing and additional objects, features and advantages of the present inventive concept will become more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein:

[0035] Figure 1 is a perspective view of a conventional wheelchair;

[0036] Figure 2 is a side view of a conventional wheelchair;

[0037] Figure 3 is a schematic side view of a wheelchair constructed in accordance with the principles of the present inventive concept;

[0038] Figure 4A is a schematic view of a drive mechanism for driving the drive wheels of a wheelchair. Figure 3

[0039] Figure 4B is a schematic view of a drive mechanism for driving the drive wheels of a wheelchair. Figure 3 Figure 4A

[0040] Figure 4C is a schematic view of a drive mechanism for driving the drive wheels of a wheelchair according to an alternative embodiment, wherein two drive assemblies are provided in a single drive mechanism. Figure 3

[0041] Figure 5 is a partial view of a conversion kit for converting a conventional manually driven wheelchair into a pump driven wheelchair according to yet another embodiment of the inventive concept.

[0042] Figure 5A is a schematic view of a conversion kit for converting a conventional wheelchair into a pump driven wheelchair according to aspects of the inventive concept.

[0043] Figure 6 is a schematic view of a conventional manually driven wheelchair having a conversion kit attached thereto to provide a pump driven wheelchair. DETAILED DESCRIPTION

[0044] Various features, advantages, and configurations of embodiments in illustrative embodiments in connection with the principles of the inventive concept are described in the following detailed description and in the appended claims. It is to be understood that the claimed invention is not limited to the specific configurations described in this detailed description and in the appended claims. Rather, the claimed invention is intended to cover all alternatives, modifications, and equivalents falling within the scope of the claimed invention. As shown throughout the drawings, various features are now described in more detail.

[0045] Reference is first made to Figure 1 and Figure 2 ​​​​The conventional wheelchair 10 includes drive wheels 52 that must be manually operated by the user. The drive wheels 52 are mounted on opposite sides of a frame 44 that holds a seat 30 for the user to sit on. The user grasps the drive wheels 52 or connected drive rims 53 with his or her hands and either advances or retreats the drive wheels 52 or causes them to remain stationary to control the forward, rearward and turning motion of the wheelchair 10. Unfortunately, these drive actions can be difficult for some individuals and can also require the user to have his / her hands in contact with the dirty wheels 52. The front wheels 50 are arranged to pivot to allow them to freely move in the direction that the wheelchair 10 is traveling. Arm rests 40 arranged on the arm supports 38 provide a place for the user to rest his / her arms. Guards 42 help prevent unwanted contact of the user or their clothing with the wheels 52. Handles 34 arranged on the bars 32 provide a means for an attendant to push or pull the wheelchair 10 to assist the user. Back rests 36 can also be arranged on the frame 44 to support the back of the user. Brake mechanisms 54 can be provided for each wheel 52 to lock the wheel 52 in place to prevent unwanted movement of the wheelchair 10. Other frame members and wheelchair components 12, 14, 16, 18, 20, 22, 26 along with other features provide stability to the wheelchair 10.

[0046] The conventional wheelchair 10 also provides foot support members 56 that include foot rests 48 mounted on leg bars 46 that extend from the frame 44. Unfortunately, however, these foot rests 48 remain stationary during operation of the wheelchair 10 and are unable to provide any therapeutic exercise for the legs of the operator of the wheelchair 10.

[0047] Figures 3 to 4C A pump-action wheelchair 100 and drive mechanisms 120, 120A are shown in accordance with the principles of the inventive concept. Figure 5 and Figure 5A A conversion kit 500 is shown for converting a conventional, manually driven wheelchair 10 into a pump-action wheelchair 100 in accordance with further principles of the inventive concept. And Figure 6 A conventional wheelchair 10 is shown with a conversion kit 500 attached thereto to provide a pump-action wheelchair 100 in accordance with the principles of the inventive concept.

[0048] Reference is made to Figures 3 to 6 In accordance with the various embodiments and principles of the inventive concept, a pump-action wheelchair 100 can be provided that has many improvements over the related art. The pump-action wheelchair 100 can also be easily stored and transported. The pump-action wheelchair 100 can be initially constructed as a pump-action wheelchair 100 or can be converted from a conventional, manually driven wheelchair 10 using an adapter or conversion kit 500.

[0049] In particular, the principles of the inventive concept provide a pump-action wheelchair 100 that can be driven using simple arm motions, such as a pump-action or a rowing action. For example, a pump (or pump-action) arm 110 can be provided that propels the vehicle 100 through a simple pump-action. The pump arm 110 can include a handlebar 112 that can be lowered for an operator to sit in a seat 130 of the wheelchair 100 and subsequently raised to an operating position to allow pumping. Alternatively, a rowing arm (not shown) can be provided along an opposite side of the wheelchair 100 that propels the vehicle 100 based on a simple rowing action. Motors (not shown) can also be provided to assist in providing power.

[0050] The front wheels 150 can be similar to the front wheels 50 of the conventional wheelchair 10 and can be freely pivoted to conform to the direction of drive. The drive wheels 152 can be substantially smaller than the drive wheels 52 of the conventional wheelchair 10 as they do not need to be operated by the wheelchair occupant. However, they can also be substantially the same or identical in size to the wheels 52 of the conventional wheelchair 10.

[0051] The pump-action wheelchair 100 according to the principles of the inventive concept can also include one or more footrests 148 that engage the operator's feet during operation of the pump arm 110 or rowing arm and move forward and backward. The footrests 148 can be mounted, for example, on struts, bars or other mechanical linkages 146 that are connected to the pump arm 110. Alternatively, fixed footrests similar to the fixed footrests 48 of the conventional wheelchair 10 can be used.

[0052] In one embodiment, the footrests 148 are arranged on both sides of the wheelchair 100 to accommodate each foot of the operator. Each footrest 148 is preferably connected to the pump arm 110 by a mechanical linkage 146, such as to an arm, bar, strut or other transfer linkage. When the pump arm 110 is actuated, the footrests 148 each move forward and backward in opposition to the movement of the handlebar 112. More specifically, when the handlebar 112 is pulled back (or back toward the operator), the footrests 148 move forward. When the handlebar 112 is pushed forward (away from the operator), the footrests 148 move backward.

[0053] The footrests 148 can have one or more guards 148a that help keep the operator's feet in place within the footrests 148 during operation. The guards 148a can be, for example, raised edges of the footrests 148 themselves or other attached ridges or structures that prevent the operator's feet from slipping out of the footrests 148. With the footrests 148 connected to the pump arm or rowing arm 110, the operator's feet can move forward and backward during operation of the vehicle 100 and provide rehabilitative exercise for the operator's legs.

[0054] The operator can also use their leg muscles to move the footrest 148 to assist the pumping action. The footrest 148 can include treads and / or friction surfaces (not shown) that help maintain traction between the operator's feet and the footrest 148. For example, treads can be formed directly on the footrest 148, or a rubber or other gripping surface can be provided on top of the footrest 148.

[0055] In embodiments having two rowing arms instead of a single pumping arm (not shown), the footrest 148 can be independently connected to a single one of the rowing arms. In this embodiment, the footrest 148 can move forward and backward in opposition to the movement of the corresponding rowing arm.

[0056] The pumping or rowing arms can be further connected to a drive mechanism 120 of the wheelchair 100 that is arranged in communication with the drive wheels 152. As noted above, the drive wheels 152 can be substantially smaller than the drive wheels 52 of the conventional wheelchair 10, as they need not be operated by the occupant. However, the drive wheels 152 can also be the same size or substantially the same size as the drive wheels 52 of the conventional wheelchair 10 to enable the operator to operate by hand, as an alternative operating mode or to facilitate manufacturing.

[0057] In one embodiment, each drive wheel 152 includes a separate drive mechanism 120. Each drive mechanism 120 can selectively drive a drive shaft 122 connected to the drive wheel 152 based on the pumping action or rowing action of the pumping or rowing arm 110 and the orientation of the handlebar 112 (or other steering control mechanism). The drive mechanisms 120 can each be configured to be selectively operated in a forward or reverse direction, and can also be configured to provide an adjustable amount of drive force.

[0058] In one embodiment, to turn the wheelchair 100, a turning mechanism 106 can be provided to the pump arms 110 to selectively engage and disengage the drive mechanisms 120 based on the orientation of a turning control mechanism 112, such as, for example, a handlebar or steering wheel. More specifically, in this embodiment, when the handlebar 112 is straight, the drive mechanisms 120 for both drive wheels 152 are driven in a forward direction by the pumping action. When the handlebar 112 is turned slightly to the right, the drive mechanism 120 for the left wheel of the wheels 152 is engaged to drive the left wheel 152 forward, while the drive mechanism 120 for the right wheel 152 is disengaged so that the right wheel of the wheels 152 is not driven forward. In this manner, the wheelchair 100 can be turned to the right. When the handlebar 112 is sharply turned to the right, the drive mechanism 120 for the left wheel is engaged to drive the left wheel of the wheels 152 forward, and the drive mechanism 120 for the right wheel is engaged in a reverse direction to drive the right wheel of the wheels 152 backward, thus causing the wheelchair 100 to make a sharp or right about turn. Alternatively, the right wheel can remain stationary during the right turning action.

[0059] Similarly, when the handlebar 112 is turned slightly to the left, the drive mechanism 120 for the right wheel of the wheels 152 is engaged to drive the right wheel forward, while the drive mechanism 120 for the left wheel of the wheels 152 is disengaged so that the left wheel is not driven forward. In this manner, the wheelchair 100 can be turned to the left. When the handlebar 112 is sharply turned to the left, the drive mechanism 120 for the right wheel is engaged to drive the right wheel of the wheels 152 forward, and the drive mechanism 120 for the left wheel is engaged in a reverse direction to drive the left wheel of the wheels 152 backward, thus causing the wheelchair 100 to make a sharp or left about turn. Alternatively, the left wheel can remain stationary during the left turning action.

[0060] In an alternative embodiment, the orientation of the turning control mechanism 112 can determine the extent of the pumping action to the individual drive mechanisms 120. For example, a gear or other force control device (not shown) can be used to control the amount of pumping force applied to the drive mechanisms 120 based on the orientation of the handlebar 112. When the handlebar 112 is straight, each drive mechanism 120 can apply an equal force to each of the drive wheels 152 to drive the wheelchair 100 in a straight line. When the handlebar 112 is rotated, a proportional force can be applied to or from the appropriate drive mechanism 120 to the drive wheels 152 based on the extent of the rotation, such that in the direction indicated by the orientation of the handlebar 112, more acute rotations of the handlebar 112 produce more acute turns, while smaller rotations produce more gradual turns.

[0061] In embodiments of the pump arm, steering can be provided by selective operation of the pump arm. Each pump arm can independently control one of the drive mechanisms. Operating one pump arm without the other, or with more force than the other, can cause the wheelchair to turn in the direction away from the pump arm with more force.

[0062] The pump (or pump) arm can further include a lever or other actuator 112a, such as a squeeze bar, that reverses the direction of drive of the wheelchair 100. When the lever 112a is pulled, the pumping action drives the drive mechanism 120 and connected wheels 152 in the reverse direction. As the lever 112a is pulled, the steering operation described above is also performed in reverse.

[0063] The pump arm 110 can include a handlebar 112 (or other steering control mechanism) that is connected to the frame 144 of the wheelchair 100 and / or the pump arm 110 such that the handlebar 112 is allowed to lower for an operator to sit into the seat 130 and raise to operate the wheelchair 100. The bottom end 110a of the pump arm 110 can be connected to the footrest 148.

[0064] The pump arm assembly 110 propels the wheelchair 100 through a simple pumping action. The footrest 148 can engage the operator's feet and move forward and backward during operation of the pump arm assembly 110. The footrest 148 can include two independent footrests 148 that are each mounted on opposite sides of the wheelchair 100. Alternatively, the footrest 148 can be a single footrest 148 that accommodates both feet. A stop (or limiter) (not shown) can be provided to limit forward and / or backward movement of the footrest 148.

[0065] The footrest 148 can be connected to the bottom end 110a of the pump arm assembly 110 by a rod or bar or other mechanical connection that provides a transfer arm or transfer link 146. The length of the transfer link 146 can be adjustable to fine tune the relationship between the pump arm assembly 110 and the footrest 148. When the pump arm 110 is actuated, the footrest 148 moves forward and backward in opposition to the movement of the pump arm handlebar 112. More specifically, when the handlebar 112 moves backward, the footrest 148 moves forward. When the handlebar 112 moves forward, the footrest 148 moves backward.

[0066] The footrest 148 can have one or more guards 148a that help keep the operator's feet in place within the footrest 148 during operation. The guards 148a can be, for example, raised edges of the footrest 148 itself or other attached ridges or structures that prevent the operator's feet from sliding out of the footrest 148. With the footrest 148 connected to the pump arm assembly 110, even when the footrest is not being used to help provide driving force, the operator's feet can be moved forward and backward during operation of the vehicle 100 and provide rehabilitative exercise to the operator's legs.

[0067] However, the operator can use their leg muscles to move the footrest 148 itself to assist the pumping action. The footrest 148 can include treads and / or friction surfaces (not shown) to help maintain traction between the operator's feet and the footrest 148. For example, treads can be formed directly on the footrest 148, or rubber or other gripping surfaces can be provided on top of the footrest 148.

[0068] The steering mechanism 106 can be provided in which the pump arm handlebar 112 (or other steering control mechanism) turns the wheelchair 100 by selective activation of the drive mechanisms 120. For example, the pump arm assembly 110 can include an actuation mechanism 106 that actuates the individual drive mechanisms 120 based on the orientation of the handlebar 112. When the handlebar 112 is facing straight ahead, both drive mechanisms 120 are driven equally by the pumping action. However, when the handlebar 112 is turned, one or more of the drive mechanisms 120 is driven by a proportionate force, disabled, or reversed in operation to effect a turning operation of the wheelchair 100 by differentially driving the drive wheels 152.

[0069] Although various possible drive mechanisms 120 are described below, any desired drive mechanism 120 can be used so long as it is capable of driving the drive wheels 152 in response to the pumping action or the pumping action of the pump arm 110 or the pumping action of the pump arm 110.

[0070] In one embodiment, each of the drive mechanisms 120 can include a drive belt 410 that travels in a loop around two wheels 402, 404. With particular reference to Figure 4A and Figure 4B In one such embodiment, the first idler wheel 402 is disposed toward the front (or rear) of the wheelchair 100. The second drive wheel 404 is fixedly attached to the drive shaft 122 to force the drive shaft 122 to rotate in the direction of rotation of the drive wheel 404. Of course, the belt 410 and wheels 402, 404 can be readily replaced with a chain and sprocket.

[0071] A drive assembly 420 can be arranged above the belt 410 and moves forward and backward in response to the action of the pumping arm 110. The drive assembly 420 can include a base 422, a bracket 424, and a drive member 426, such as a latch, pivotably mounted in the bracket 424. The drive latch 426 can be biased to a forward drive position by a spring 428, or it can be activated to the forward drive position by a squeeze lever 112a on the handle 112 or other mechanism or any other mechanical or electrical assisted activation device.

[0072] With particular reference to Figure 4A In the forward drive position, a first engagement end 426a of the drive latch 426 engages the teeth 410a in the belt 410. The first engagement end 426a of the latch 426 is designed to engage the teeth 410a of the belt 410 when moving in the first (forward) direction, but to slide past the teeth 410a without engaging when moving in the second, opposite direction. In this way, when the drive mechanism moves forward in response to the pumping action, the first engagement end 426a of the latch 426 engages the teeth 410a of the belt 410 to drive the belt 410 forward. As it does so, the drive wheel 404 is driven forward, driving the axle 122 (along with the connected drive wheels 152) in the forward direction as well. Thus, the wheelchair 100 is driven forward in response to the movement of the pumping arm assembly 110.

[0073] A reverse mechanism can also be provided, enabling operation in the reverse direction. The reverse mechanism can operate by pivoting the drive member 426 into a reverse position against the force provided by the spring 428. This can be achieved, for example, using a squeeze handle 112a arranged on the handle bar 112, or by using some other lever or switch that can be connected to the drive mechanism 120 by a cable, for example. With particular reference to Figure 4B When the reverse mechanism is actuated, the drive member (latch) 426 is pivoted so that an opposite, second engagement end 426b of the drive member 426 engages the teeth 410a of the belt 410. The second engagement end 426b of the drive member 426 is configured to engage the teeth 410a of the belt 410 when moving in the backward direction, but to slide freely without engaging the belt 410 when moving in the forward direction. In this way, with the reverse mechanism engaged, the drive mechanism 426 engages and drives the belt 410 in the backward direction, causing the drive wheel 404, the axle 122, and the drive wheels 152 to move in the reverse direction. The wheelchair 100 is thus driven backward in response to the pumping action.

[0074] In Figure 4C In the alternative embodiment shown, the drive mechanism 120A includes two drive assemblies 420a, 420b to drive each belt 410 or chain. This embodiment can be useful, for example, when a draw arm is used instead of a pumping arm.

[0075] In addition to forward and reverse gears, a neutral gear can be provided in which movement of the drive wheels 152 does not move the pump arm 110 or footrest 148. For example, the neutral gear can be provided with the pump arm 110 not engaging the drive mechanism 120, the drive mechanism 120 not engaging the belt 410, or the drive wheels 152 not engaging the drive shaft 122. The neutral gear can be selected by the service provider or the rider, and can be provided to disengage the pump action when the service provider wishes to push or pull the wheelchair 100 without possible interference from the rider, or when the rider of the wheelchair 100 wishes to coast without movement of the pump arm 110 or footrest 148.

[0076] In another embodiment (not shown), the drive mechanism can include a drive chain that travels in a loop around two sprockets. A first idler sprocket can be disposed in front of (or behind) the second drive sprocket, near the front (or rear) of the wheelchair. Alternatively, the first sprocket can be disposed above (or below) the second drive sprocket. The second drive sprocket can be fixedly attached to the drive shaft, to force the drive shaft to rotate in the direction of rotation of the drive sprocket.

[0077] The forward drive catch can be disposed above the chain, and moves forward and backward (or up and down) in response to the pump action. The forward drive catch catches on the chain above, and as the footrest is moved forward, it catches and pulls on the top section of the chain. As the top of the chain is driven forward, the rearward drive sprocket is also driven forward with the shaft and attached wheels. Thus, the wheelchair is driven forward in response to the pump arm movement. The forward drive catch can be configured to catch by default, or it can be activated by a squeeze lever on the handle or other mechanism or any other mechanical or electrical assisted activation. In embodiments with an activation mechanism, the forward drive catch can only catch on the chain and catch the chain when activated, and the drive mechanism can default to a neutral position.

[0078] The forward drive catch can provide a ratchet-like action that catches the chain and drives it forward during forward movement of the catch, and is free to slide backward without catching the chain. For example, this can be achieved by providing an engagement edge on the forward end of the catch that catches on the chain as the forward drive catch is moved forward. However, the rearward end of the catch can be open, or angled away from the chain, so that the forward drive catch is free to slide backward without engaging the chain.

[0079] The reverse mechanism can be presented in a similar manner. Specifically, a rearward drive latch can also be provided over the bottom section of the chain and move forward and backward (or up and down) in response to a pumping action. The rearward drive latch can be activated by a squeeze handle or other activation device. When activated, the rearward drive latch snaps over the chain and catches on the bottom of the chain and pulls forward as the rearward drive latch moves forward as the pumping arm is pulled. As the bottom of the chain is pulled forward, the drive sprocket and drive shaft are driven in reverse, causing the wheelchair to move backward. When the reverse drive latch is activated, the forward drive latch should also be deactivated. The reverse drive latch can have a ratchet-like configuration similar to the forward drive latch such that it catches and pulls the chain during forward motion, but slides freely along the chain during backward motion.

[0080] In another alternative embodiment (not shown), the chain can be replaced by a belt, rope, cable, cord or other drive system that wraps around an idler wheel or pulley and a reverse drive shaft. The belt, rope, cable or cord can be configured to provide drive force to the shaft, and a forward drive latch and a reverse drive latch can be configured to pull the shaft in a forward direction along the top or bottom of the belt, rope, cable or cord, respectively, to drive the shaft in a desired direction for forward or backward motion of the wheelchair.

[0081] In another embodiment (not shown), each drive mechanism includes one or more sprockets arranged on the shaft with a drive wheel. The sprocket receives a chain connected to a pumping or paddle arm, such as by a footrest, and rotates in response to arm motion. The gears on the sprocket mesh with a drive gear connected to the drive wheel to drive the drive wheel.

[0082] In yet another embodiment (not shown), two sprockets are provided on the drive assembly to selectively allow the wheelchair to move forward or backward based on pumping arm action. A first sprocket is connected to a forward drive gear, both of which are rotatably and slidably mounted on the shaft on one side of the drive wheel. A second sprocket is connected to a reverse drive gear, and both are rotatably and slidably mounted on the shaft on an opposite side of the drive wheel from the first sprocket. The first and second sprockets drive their corresponding gears in only one direction (forward or reverse, respectively), while freely spinning in the opposite direction.

[0083] A chain and spring assembly can be provided for each sprocket. A first chain is arranged such that a first end of the first chain is connected to the pump assembly. The first chain extends from the pump assembly to the top of the first sprocket and then around the first sprocket. A second end of the first chain that extends below the first sprocket is connected to one end of a first spring, the other end of the first spring being connected to the frame. When the pump arm is actuated (pulled back), the pump arm pulls the first chain along with it. When the first chain is pulled, it drives the first sprocket and the connected forward drive gear in the forward direction and stretches the first spring. When the pump arm moves forward again, the first spring pulls the first chain back to its original position.

[0084] A second chain is arranged such that a first end of the second chain is connected to one end of a spring, the other end of the spring being connected to the frame. The chain extends from the spring to the top of the second sprocket and then around the sprocket. A second end of the second chain that extends below the second sprocket is connected to the pump assembly. When the pump arm is actuated, the second chain drives the second sprocket and the connected reverse drive gear in the reverse direction. When the pump arm moves forward again, the second spring pulls the second chain back to its original position.

[0085] A chain retention system can be provided for one or both chains to reduce the length of spring needed to retract the chain to its original position. The chain retention system can include a pulley mounted on the end of a lever arm that is pivotably mounted to the frame. Rather than attaching the spring to the end of the chain, the spring is attached to the lever arm so that the lever arm is biased in the extended position. The chain is connected to the frame at a first end near the chain retention system and extends around the pulley to the sprocket and then around the sprocket to the footrest connection point. When the pump arm is retracted and the footrest moves forward, the chain pulls the pulley and lever arm down and stretches the spring. When the pump arm moves forward, the spring pulls the lever arm to lift the lever arm back to its extended position and return the chain to its starting position.

[0086] In this embodiment, the drive wheel hub can be rotatably mounted at the center of the axle. The drive wheel gear can be rotatably arranged on the hub and the drive wheel can be rigidly affixed to the drive wheel gear to rotate with the drive wheel gear. The drive wheel gear preferably includes teeth on both the right and left sides of the drive wheel gear.

[0087] The first and second sprockets can be connected to each other by the drive wheel hub using one or more pins or other mechanical connectors to maintain them at a constant predetermined distance from each other. The mechanical connectors between the sprockets preferably maintain the constant distance between the first and second sprockets (and their associated gears) as they slide back and forth along the axis. One or more springs arranged on the axis preferably bias the sprockets to a position in which the forward drive gear connected to the first sprocket is in mesh with the first side of the drive wheel gear, which is on the same side of the drive wheel as the first sprocket. With the forward drive gear in mesh, as the pump arm is operated, the drive wheel is driven to rotate forward, causing the wheelchair to move forward.

[0088] A squeeze lever (lever) is preferably provided on one side of one of the pump arm handles or paddle handles. The squeeze lever can be connected to the actuator lever or transfer mechanism by a cable system. The actuator lever (or arm) is preferably connected to the sprocket assembly. When the squeeze lever is squeezed, the cable tightens and activates the actuator arm or transfer mechanism to move the sprocket assembly. More specifically, in response to the squeezing of the squeeze lever, the actuator arm or transfer mechanism slides the sprocket assembly into the reverse position against the spring bias. For example, the actuator arm can be a curved rod or lever that communicates with the second sprocket.

[0089] For example, the squeeze lever can be configured so that a squeeze of ¾ inch or less is sufficient to move the sprocket assembly between its forward and reverse positions. When the sprocket assembly is slid into the reverse position, the forward drive gear disengages from the drive wheel gear, and the reverse drive gear connected to the second sprocket engages the drive wheel gear on the opposite side from the forward drive gear. In this position, as the pump arm is operated, the drive wheel is driven in the reverse direction, causing the vehicle to move backward.

[0090] Of course, any other desired actuation mechanism (whether mechanical, electrical, or a combination of the two) can be used, such as a lever, button, dial, slider, or other device to switch the sprockets from their forward drive engagement to their reverse drive engagement. Once the actuation or transfer mechanism is deactivated, the biasing spring drives the first sprocket and forward drive gear back into engagement with the drive wheel gear and out of engagement with the reverse drive gear, so that operating the pump arm will again drive the vehicle to move forward. The teeth of the drive gear and drive wheel gear can be beveled or angled on their non-driving edges to allow for automatic alignment as the drive gear is moved into place.

[0091] Similar drive systems can also be applied to pedal and other vehicles to switch from forward to reverse. In embodiments with two handles, such as a paddle design, additional sprockets can be provided on each side of the drive wheel. The additional sprockets facilitate relative forward and backward movement of the two handles.

[0092] Although various specific drive mechanisms have been described above, any other type of drive mechanism can also be envisioned, so long as it drives the drive wheels based on a pumping, stroking, or similar type of motion.

[0093] A braking system (not shown) can also be provided. The braking system can include a brake lever that pushes against one or more of the drive wheels when the brake is actuated. The brake can be actuated using a squeeze lever disposed on the handlebar opposite the reverse actuation mechanism. The squeeze lever can be connected to the brake lever by a cable system. When the brake squeeze lever is squeezed, the cable tightens and pulls the brake lever upward against the drive wheels. The braking system can be lockable to lock the brake in place and prevent the vehicle from moving. For example, the brake locking system can be a toggle-type system in the squeeze lever, or a separate latch that folds over the squeeze lever and locks it in place. Of course, the braking system can be actuated in any other desired manner, and include any other desired type of braking system. For example, the handlebar connected to the frame can be used to actuate and release the brake.

[0094] The drive wheels can each include an inflatable tire having a tread pattern disposed thereon that is designed to engage the ground and provide sufficient traction for the vehicle to move over any terrain.

[0095] The wheelchair can be foldable to facilitate transport or storage. More specifically, the wheelchair can be able to be collapsed in a manner similar to a conventional wheelchair.

[0096] Referring now to Figure 5 , Figure 5A and Figure 6 , according to one embodiment, a conversion kit 500 can be provided to convert a conventional, manually driven, or other wheelchair 10 into a pump-driven wheelchair 100. The conversion kit 500 can be a universal conversion kit designed to retrofit any of a variety of different conventional wheelchairs 10 into a pump-driven wheelchair 100. For example, the conversion kit 500 can be designed to be secured to a conventional, manually driven wheelchair 10 at one or more anchor points 502 using a clamp system 504 or other connection mechanism. In the illustrated embodiment, the conversion kit 500 is designed to be connected to a conventional wheelchair 10 using clamps 504 or other connection mechanisms at three or more points 502 along each side of the wheelchair 10. These connection points 502 can be common to many, if not all, conventional, manually driven wheelchairs 10.

[0097] In these embodiments, the wheels 52 of a conventional wheelchair 10 are removed and then reattached to the drive shafts 122 on the conversion kit 500. The conversion kit 500 clamps to the conventional wheelchair 10 at the desired attachment points 502. The conversion kit 500 provides one or more pump arms 110 that are connected to the drive shafts 122 by a drive mechanism 120 to propel the wheels 152 in response to the pumping action of the pump arms 110. The drive mechanism 120 can drive the movement of the drive shafts 122 and the attached wheels 152 in response to forward and backward movement of the pump arms 110 or in response to movement of the pump arms 110 in the forward or backward direction. A neutral gear can also be provided in which the pump arms 110 are disengaged from driving the wheels 152.

[0098] A steering mechanism 106 can be provided with a steering control mechanism 112 to steer the wheelchair 100 by selectively driving the left and right drive shafts 122 in the desired amount in response to turning of the steering control mechanism 112, as previously described. A reverse mechanism 112a (see Figure 3 ) can also be provided that allows the pumping action to drive the wheelchair in reverse when activated.

[0099] The conversion kit 500 can further provide pump footrests (not shown) connected to the pump arms 110 or the conventional fixed footrests 48 can be retained.

[0100] Various other designs and embodiments can also be contemplated without departing from the spirit and scope of the inventive concepts, and numerous variations to the specific designs described above are possible. For example, the belt or chain can be a belt, chain, rope, cable, or any other structure or material that winds around a pulley or gear. The drive mechanism can have a clamp, actuator, or catch on one or both sides of the belt, chain, rope, cable, or other material. If arranged on both sides, the mechanism can be configured to snap on opposite sides and move in opposite directions. The principles of these inventive concepts can also be used for motorized vehicles other than wheelchairs.

[0101] In another alternative embodiment (not shown), a small electric motor can be provided as an assist mechanism to help propel the wheelchair. In one embodiment, one or more sensors can be provided to sense resistance when the operator attempts to operate the pump arms and propel the wheelchair. If a significant amount of resistance is detected (such as on a hill or for a user with less arm strength or dexterity), the sensors can detect this and engage the electric motor. The electric motor is preferably connected to the drive shafts to provide an assistive driving force to the vehicle when needed. The electric motor can also be controllable to drive the shafts in the forward or reverse direction.

[0102] A user selectable switch or other user selectable control means can be provided to enable the user to select the amount of assistance from the motor that is desired. For example, the user can select to operate the vehicle entirely manually, or the user can select up to the maximum amount of assistance from the motor. Preferably, the switch or other user selectable control means allows a wide range of selection between minimum assistance and maximum assistance.

[0103] Having described and shown the principles of the inventive concept in various preferred embodiments thereof, it is to be understood that the application can be modified in arrangement and detail without departing from the principles thereof. CLAIM (MODIFIED IN ACCORDANCE WITH ARTICLE 19 OF THE TREATY) 1. A conversion kit for converting a conventional wheelchair comprising a frame into a pump-action wheelchair, the conversion kit comprising: a pump-action arm configured to be connected to the frame and further configured to pivot rearward and forward about a pivot point to provide a pump-action or a stroke-action to the wheelchair; a first drive mechanism configured to be connected to a drive wheel arranged on a first side of the wheelchair to drive a first one of the drive wheels in response to the pump-action or the stroke-action; a second drive mechanism configured to be connected to a drive wheel arranged on a second side of the wheelchair to drive a second one of the drive wheels in response to the pump-action or the stroke-action; an attachment mechanism configured to attach the conversion kit to the conventional wheelchair; and a steering mechanism having a steering control mechanism, wherein a driving force applied to the drive wheels by the first and second drive mechanisms is controlled based on an orientation of the steering control mechanism such that rotation of the steering control mechanism causes the force applied by the first drive mechanism to differ from the force applied by the second drive mechanism to cause the wheelchair to steer. 2. The conversion kit of claim 1, wherein the conversion kit is collapsible with the frame of the conventional wheelchair to reduce an amount of storage space and to facilitate easy transportation of the pump-action wheelchair. 3. The conversion kit of claim 1, further comprising a handlebar disposed on the pump-action arm, the handlebar being lowerable to allow an operator to more easily sit into the wheelchair and subsequently raised to an operating position prior to performing the pump-action. 4. The conversion kit of claim 1, further comprising a footrest connected to the pump-action arm such that the footrest moves forward and rearward in response to the pump-action. 5. The conversion kit of claim 1, wherein the steering mechanism comprises a handle that can be rotated. 6. The conversion kit of claim 1, wherein the steering mechanism is configured to cause the drive mechanism to provide a proportional force to each of the drive wheels in accordance with the extent to which the steering control mechanism is rotated. 7. The conversion kit of claim 1, wherein when the steering control mechanism is rotated in one direction to a maximum amount, the steering mechanism causes an appropriate one of the drive mechanisms to operate in reverse. 8. A conversion kit for converting a conventional wheelchair comprising a frame having a seat disposed between two drive wheels into a pump-action wheelchair, the conversion kit comprising: one or more pump-action arms each configured to be connected to the frame and each configured to pivot rearward and forward about a pivot point to provide a pump-action or a rowing action to drive the drive wheels of the wheelchair; a first drive mechanism configured to drive a first one of the two drive wheels in response to the pump-action or rowing action; a second drive mechanism configured to drive a second one of the two drive wheels in response to the pump-action or rowing action; one or more removable attachment mechanisms configured to attach the first and second drive mechanisms to the conventional wheelchair; and a steering mechanism having a steering control mechanism, wherein drive forces applied to the drive wheels by the first and second drive mechanisms are controlled based on an orientation of the steering control mechanism to cause the force applied by the first drive mechanism to differ from the force applied by the second drive mechanism to cause the wheelchair to turn. 9. The conversion kit of claim 8, wherein each drive mechanism is driven by a separate pump-action arm. 10. The conversion kit of claim 8, wherein a single pump-action arm drives both the first and second drive mechanisms. 11. The conversion kit of claim 10, further comprising a handlebar disposed on the pump-action arm that can be lowered to allow an operator to more easily sit into the wheelchair and subsequently raised to an operating position prior to performing the pump-action. 12. The conversion kit of claim 10, further comprising a footrest connected to the pump-action arm such that the footrest moves forward and rearward in response to the pump-action. 13. The conversion kit of claim 10, wherein the steering control mechanism is disposed on the pump arm, wherein a driving force applied to the drive wheels by the first and second driving mechanisms is controlled based on an orientation of the steering control mechanism such that rotation of the steering control mechanism causes the force applied by the first driving mechanism to differ from the force applied by the second driving mechanism to cause the wheelchair to steer. 14. A conversion kit for converting a traditional wheelchair to a pump-action wheelchair, the conversion kit comprising: an attachment mechanism configured to secure the conversion kit to the traditional wheelchair at one or more points along a frame of the traditional wheelchair; a pump arm configured to allow an operator to drive the wheelchair using a pump action or a sweep action; a drive shaft configured to be secured to a drive wheel of the wheelchair and further configured to drive the drive wheel secured to the drive shaft in response to a pump action or a sweep action of the pump arm; and a steering mechanism having a steering control mechanism, wherein the steering mechanism is configured to control an amount of driving of each of the drive wheels as a function of an amount of rotation of the steering control mechanism. 15. The conversion kit of claim 14, wherein the conversion kit is a universal conversion kit configured to be attached to many different types of traditional wheelchairs. 16. The conversion kit of claim 14, wherein the attachment mechanism comprises three or more clamping mechanisms configured to secure the conversion kit to a frame of the traditional wheelchair. 17. The conversion kit of claim 14, further comprising one or more footrests configured to move forward and backward in response to the pump action or the sweep action. 18. The conversion kit of claim 14, wherein the steering mechanism comprises a rotatable handle. 19. The conversion kit of claim 14, wherein the steering mechanism is configured to cause the drive shaft to provide a proportional force to each of the drive wheels as a function of an amount of rotation of the steering control mechanism. 20. The conversion kit of claim 14, wherein when the steering control mechanism is rotated to a maximum amount in one direction, the steering mechanism causes an appropriate one of the drive shafts to move in reverse.

Claims

1. A conversion kit for converting a conventional wheelchair comprising a frame into a pump-action wheelchair, the conversion kit comprising: a pump arm configured to connect to the frame and further configured to pivot rearward and forward about a pivot point to provide a pump action or a stroke action to the wheelchair; a first drive mechanism configured to connect to a drive wheel disposed on a first side of the wheelchair to drive a first one of the drive wheels in response to the pump action or stroke action; a second drive mechanism configured to connect to a drive wheel disposed on a second side of the wheelchair to drive a second one of the drive wheels in response to the pump action or stroke action; and an attachment mechanism configured to attach the conversion kit to the conventional wheelchair. The conversion kit is capable of being collapsed with the frame of the conventional wheelchair to reduce the amount of storage space and to facilitate easy transportation of the pump-action wheelchair.

2. The conversion kit of claim 1, wherein, 3. The conversion kit of claim 1, further comprising a handlebar disposed on the pump arm, the handlebar being capable of being lowered to allow an operator to more easily sit into the wheelchair and subsequently raised to an operating position prior to performing the pump action.

4. The conversion kit of claim 1, further comprising a footrest connected to the pump arm such that the footrest moves forward and rearward in response to the pump action. The drive force applied to the drive wheels by the first and second drive mechanisms is controlled based on the orientation of the steering control mechanism such that rotation of the steering control mechanism causes the force applied by the first drive mechanism to differ from the force applied by the second drive mechanism to cause the wheelchair to turn.

5. The conversion kit of claim 1, further comprising a steering mechanism having a steering control mechanism, wherein, The steering mechanism is configured to cause the drive mechanisms to provide a proportional force to each of the drive wheels according to the extent to which the steering control mechanism is turned.

6. The conversion kit of claim 5, wherein, When the steering control mechanism is turned in one direction to a maximum amount, the steering mechanism causes an appropriate one of the drive mechanisms to operate in reverse.

7. The conversion kit of claim 5, wherein, 8. A conversion kit for converting a conventional wheelchair comprising a frame into a pump-action wheelchair, the frame having a seat disposed between two drive wheels, the conversion kit comprising: one or more pump arms each configured to connect to the frame and each configured to pivot rearward and forward about a pivot point to provide a pump action or a stroke action to drive the drive wheels of the wheelchair; a first drive mechanism configured to drive a first one of the two drive wheels in response to the pump action or stroke action; a second drive mechanism configured to drive a second one of the two drive wheels in response to the pump action or stroke action; and one or more removable attachment mechanisms configured to attach the first and second drive mechanisms to the conventional wheelchair. Each drive mechanism is driven by a separate pump arm. ​ 9. The conversion kit of claim 8, wherein, ​ 10. The conversion kit of claim 8, wherein, A single pump arm drives both the first drive mechanism and the second drive mechanism.

11. The conversion kit of claim 10, further comprising a handlebar disposed on the pump arm, the handlebar being lowerable to allow an operator to more easily sit into the wheelchair and subsequently raised to an operating position prior to performing the pump action.

12. The conversion kit of claim 10, further comprising a footrest connected to the pump arm such that the footrest moves forward and backward in response to the pump action.

13. The conversion kit of claim 10, further comprising a steering mechanism having a steering control mechanism disposed on the pump arm, wherein, The drive force applied to the drive wheels by the first and second drive mechanisms is controlled based on the orientation of the steering control mechanism such that rotation of the steering control mechanism causes the force applied by the first drive mechanism to differ from the force applied by the second drive mechanism to cause the wheelchair to steer.

14. A conversion kit for converting a traditional wheelchair into a pump-action wheelchair, the conversion kit comprising: an attachment mechanism configured to secure the conversion kit to the traditional wheelchair at one or more points along a frame of the traditional wheelchair; a pump arm configured to allow an operator to drive the wheelchair using a pump action or a rowing action; a drive shaft configured to be secured to drive wheels of the wheelchair and further configured to drive the drive wheels secured to the drive shaft in response to a pump action or a rowing action of the pump arm.

15. The conversion kit of claim 14, wherein, The conversion kit is a universal conversion kit configured to be attached to many different types of traditional wheelchairs.

16. The conversion kit of claim 14, wherein, The attachment mechanism comprises three or more clamping mechanisms configured to secure the conversion kit to a frame of the traditional wheelchair.

17. The conversion kit of claim 14, further comprising one or more footrests configured to move forward and backward in response to the pump action or the rowing action.

18. The conversion kit of claim 14, further comprising a steering mechanism having a steering control mechanism, wherein, The steering mechanism is configured to control an amount of drive of each of the drive wheels as a function of an amount of rotation of the steering control mechanism.

19. The conversion kit of claim 18, wherein, The steering mechanism is configured to cause the drive shaft to provide a proportional amount of force to each of the drive wheels as a function of an amount of rotation of the steering control mechanism.

20. The conversion kit of claim 18, wherein, When the steering control mechanism is rotated to a maximum amount in one direction, the steering mechanism causes an appropriate one of the drive shafts to move in reverse.

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