HK1078761B - Manually propelled vehicle and control assembly thereof - Google Patents

Description

Manually propelled vehicle and control assembly thereof

Technical Field

The present invention provides a propulsion, braking, anti-rollback and control assembly for a manually propelled vehicle, such as a wheelchair. In one embodiment, the invention provides a control lever assembly, seat actuation auxiliary brake system and associated force transfer system that propel, brake and steer a wheelchair in a safe and mechanically advantageous manner while minimizing rollback of the vehicle. In addition, the present invention provides a selective anti-rollback disengagement system that facilitates selective and controlled rearward movement in situations where some vehicle rollback is desired.

Background

Almost all wheelchairs include a rear wheel lock that prevents the wheelchair from rolling when a passenger attempts to sit in or stand up from the chair. Many wheelchairs also employ anti-rollback apparatus because many occupants are often prevented from engaging these locks by their fragile physical or mental state. Anti-rollback apparatus, including clutches and rack and pinion systems, such as those described in U.S. patents 6371503, 63471088, 6203041 and 4538825, prevent unintended backward movement of the wheelchair when passengers attempt to enter and exit the chair or propel it uphill.

However, sometimes passengers need to be able to move the wheelchair backwards in order to best manoeuvre the wheelchair, and ingress and egress to and from an elevator is an example of such a situation where selective disengagement of the anti-rollback apparatus is desirable.

Pushing a hand propelled wheelchair up an incline has proven difficult even if the chair is equipped with anti-rollback means. The passenger must use both hands to generate enough force to accelerate by the rapid rotation of the drive wheels, pushing the combined weight of the passenger plus chair up the ramp, not all passengers are strong enough to do so, and it is also unsafe or inconvenient for the passenger to use both hands entirely to propel the chair. Some wheelchair occupants may not have hands available and thus the amount of force they can generate is limited. Even if the occupant is strong enough to push the wheelchair up the incline a considerable distance, the inherent mechanical disadvantage of current chair designs prevents an effective conversion of linear acceleration forces to thrust forces up the incline, and thus the chair may roll backwards, even if equipped with an anti-rollback apparatus.

Braking while descending a slope is another problem. Current wheelchairs are designed to rely on wheel mounted brakes to slow the chair as it travels down the slope, and these designs have also proven to be inefficient in slowing the chair to a safe speed. These systems may require the passenger to divert their attention away from controlling the direction of the chair and require him to transfer one or both of his hands from the steering device to the braking device, the wheelchair being temporarily out of control during a dangerous downhill descent.

While motorized wheelchairs address these problems to some extent, many users cannot afford to purchase such chairs, and thus, it is desirable to provide a means for propelling, steering and braking a hand-propelled wheelchair with a single hand to provide safe transport to those who cannot afford or use the motorized wheelchair. The foregoing solutions should be equally applicable to any type of manually propelled vehicle, including hand trucks and toy vehicles. Although the occupants of these vehicles may not be handicapped or infirm, they may lack the dexterity and strength to propel, brake and steer manually propelled vehicles.

Disclosure of Invention

It is an object of the present invention to provide an improved manually propelled vehicle and an improved control assembly for such a manually propelled vehicle.

It is another object of the present invention to provide an improved manually propelled vehicle, such as a wheelchair, which provides one-handed steering, propulsion, braking, and minimal rollback.

It is another object of the present invention to provide an improved manually propelled vehicle, such as a wheelchair, which provides one-handed steering, propulsion and braking and selective rollback.

It is a further object of the present invention to provide an improved manually propelled vehicle, such as a wheelchair, which provides one-handed steering, propulsion and braking, facilitates selective rollback, and provides a seat actuated auxiliary drive wheel braking system.

In accordance with the above objects, the present invention provides an improved manually propelled vehicle, such as a wheelchair, that provides one-handed steering, propulsion and braking, facilitates selective rollback, and provides a seat actuated auxiliary drive wheel braking system.

The present invention includes a novel control arrangement including a control lever assembly for steering, propelling and braking a manually propelled vehicle and enhancing rollback prevention. The present invention also provides an auxiliary braking system that is actuated by an occupant of a manually propelled vehicle by moving a vehicle seat along a support frame. Additionally, the present invention, in one embodiment, comprises a system that facilitates selective rollback. The system and apparatus of the present invention have proven to be particularly useful for wheelchair applications.

In one embodiment of the invention, a wheelchair includes a frame, a front steering wheel assembly having at least two pivotable steering wheels connected to steering wheel shafts, and a rear drive wheel assembly including at least one drive wheel mounted on a rear drive wheel shaft. The rear drive wheel assembly further includes an anti-rollback apparatus and a one-way engagement apparatus, both of which are axially mounted on the rear drive wheel shaft. The front steering assembly and the rear drive wheel assembly support the frame and enable movement of the vehicle. An adjustable footrest is located horizontally within the frame above the front steering wheel assembly, and a front steering wheel shaft is pivotally connected to the bottom of the footrest. A seat configured and oriented to support an occupant is also provided, the seat being mounted for limited horizontal sliding movement (e.g., a few inches) on the frame by known means such as roller and rail or linear bearing connection systems. The seat is connected by means such as a lever engaged to a friction pad to brake the drive wheel, or by a hydraulic brake actuator connected to a rear drive wheel brake actuation system, whereby movement of the seat in a forward direction actuates the brake system.

The wheelchair has a control device that includes a control lever assembly having a plurality of engagement points, such as slotted holes, that extend along the length of the control lever assembly. The control lever assembly is pivotally affixed at its bottom end to the top of the footrest for limited fore and aft movement along the pivot axis from a vertical orientation. A sleeve arranged to move over the exterior of the control lever assembly, a plurality of engagement points, such as slotted holes, extending along the length of the sleeve; these engagement points may be positioned to overlap one or more of the engagement points of the control lever assembly. The control lever assembly is connected by a standard brake actuation system (e.g., a hydraulic brake actuation system) to a drive wheel braking system that includes a brake disc that is axially mounted on the rear drive wheel shaft. A force transmitting connector, such as a rigid rod, cable or chain, is connected at one end to a single direction engagement means, such as a single direction rotating disc axially mounted on the drive wheel shaft, and affixed at the other end to the sleeve. When engaged, the one-way clutch helps prevent rollback.

In one embodiment, the force transfer linkage is connected to a single direction rotating disc that is axially mounted on the rear drive wheel shaft and has a ratchet and pawl mechanism that engages the rear drive wheel shaft for propulsion and ensures single direction movement. The engagement of the ratchet with the pawl ensures unidirectional rotation. The axially mounted single direction rotating disc is also resiliently connected to the frame, for example by a spring, to limit disc rotation. In one embodiment, the anti-rollback apparatus comprises a circumferentially apertured disc axially mounted on the drive wheel shaft and locked in position by connection with a retractable locking pin mounted on the frame for connection with the disc aperture. In another embodiment, the one-way engagement means is a one-way ratchet wheel mounted for engagement on the rear drive wheel shaft. Those skilled in the art will appreciate that other variations of the one-way engagement devices and force transfer connections may be employed.

The control device also includes a rotating steering column that (i) extends through and is arranged to move within the control lever assembly, and (ii) ensures that one of the front steering wheel shafts turns and steers through a flexible joint or universal joint. The steering column includes an engagement member, such as a locating pin, which can be positioned to simultaneously engage an engagement point (say a slotted hole) of the sleeve and the control lever assembly by movement of the steering column, thereby locking the sleeve in a fixed position along the control lever assembly. The steering column may be used to turn and steer the front steering wheel(s) simultaneously and has a handle to facilitate engagement by the chair occupant.

The control lever assembly may be used to propel the vehicle as follows. The occupant manipulates the steering column handle to adjust the bushing, and thus the force transfer linkage, to a position that facilitates propulsion in a particular environment. By noticing the resistance he is subjected to when propelling the vehicle, the passenger will intuitively determine the most advantageous position. By manipulating the steering column, the occupant pushes the control lever assembly in a forward direction from a vertical orientation, thereby transmitting a propulsive force through the force transmitting linkage that causes the one-way clutch to rotate in the forward direction, and thus the drive wheel shaft, in the forward direction. For example, where the single direction engagement means is a disc, when the lever assembly is pushed forwardly, the disc rotates in a forward direction to an extent limited by the tension exerted on the single direction rotating disc by the resilient coupling, e.g. a spring, thereby transferring the forward propulsion force to the rear drive wheel shaft. The most efficient transfer of propulsion occurs when the steering column is adjusted to lock the sleeve in a position along the control lever assembly closest to the footrest, such as closest to the pivot mounting the control lever assembly to the frame. The anti-rollback apparatus and the one-way clutch apparatus help prevent the rear drive wheel from rolling backward.

When used in conjunction with known anti-rollback mechanisms, the control device of the present invention provides up to ten times or more of the mechanical advantage in transferring the propulsive force applied by an occupant pushing the control lever assembly in a forward direction to the drive axle.

The control lever assembly may be used to brake the vehicle as described below. As mentioned, the control lever assembly is connected by standard brake actuation equipment and linkages (e.g., a hydraulic brake actuation system) to a drive wheel braking system including a brake disc axially mounted on the rear drive wheel shaft. Pulling the control lever assembly rearward from the vertical orientation activates the brake actuation device and causes the brake disk to engage the drive wheel shaft.

The auxiliary braking system is activated by displacing the seat forward, either by weight deflection of the occupant or by gravity in downhill motion, as described below. In one example, the top end of a lever pivotally mounted on the frame engages the bottom of the seat via a flexible or rigid linkage, and as the seat slides forward along the frame, the seat moves causing the lever to pivot and engage or disengage contact between a brake pad rotatably mounted on the bottom of the lever and the rear drive wheel. Thus, by forward seat displacement, additional braking is applied to the rear drive wheels during downhill motion, and the passenger's hands are freed for steering during downhill, since the auxiliary braking system can be engaged by gravity only.

The anti-rollback disengagement system of the present invention includes a handle mounted on the frame or control lever assembly, the handle being connected by a release cable in a manner to effect engagement and disengagement of either or both of the anti-rollback apparatus and the one-way engagement apparatus. For example, in the aforementioned example of a disc-type one-way engagement device and an anti-rollback device, the disengagement cable may disengage the anti-rollback locking pin and the pawl of the pawl-and-ratchet mechanism, allowing the mechanism to rotate in both directions to a limited extent.

Each of the foregoing features of the present invention may be used in conjunction to provide safe and efficient vehicular transport in various modes of operation.

Drawings

FIG. 1 shows a side view of a wheelchair employing the control assembly of the present invention and depicting the interrelationship of the control lever assembly with a seat-actuated auxiliary brake system;

FIG. 2 shows a perspective view of the control lever assembly, the sleeve and the steering column, further illustrating the connection of the control lever assembly to the pivot and the connection of the steering column to the drive axle via the flexible joint;

FIG. 3 illustrates the control lever assembly advance and brake strokes;

FIG. 4 shows a perspective view of a one-way splice tray, anti-rollback mechanism, and force transfer cable;

FIG. 5 shows a perspective view of the cable anti-rollback disengagement mechanism, the one-way clutch discs, and the circumferentially apertured anti-rollback discs;

FIG. 6 shows a perspective view of a release handle used in the mechanism of FIG. 5 and the engagement of the handle with a vehicle frame to which the locking tab is mounted;

FIG. 7 shows a side view of the hydraulic seat actuation supplemental brake system;

FIG. 8 shows a perspective view of the hydraulic anti-rollback disengagement mechanism;

FIG. 9 shows a perspective view of a one-way engagement device in the form of a ratchet drive connected to a force transfer linkage in the form of a rigid rod.

Detailed Description

The following detailed description is directed to a wheelchair employing the control assembly, seat actuated auxiliary brake system and anti-rollback disengagement system of the present invention. Manually propelled vehicles, such as toy carts or cars, golf carts or other recreational vehicles, hand propelled equipment for security personnel, or work vehicles such as messenger carts used in a factory environment, can also employ these systems or components and are within the scope of the present invention.

A wide variety of components may be used in the control assembly, seat actuation supplemental brake system, and anti-rollback disengagement system described below. For example, the axially mounted anti-rollback apparatus locked with a pin is one of the various anti-rollback apparatuses that can be employed. The force transfer connection can take many forms, such as a wire, cable, chain or rod that can withstand the propulsive and anti-rollback stresses associated with operation of an occupied vehicle, such as a wheelchair. The engagement points and engagement members may be detents and grooves or other suitable engagement members. The control lever assembly can be connected to drive the wheel brake system after activation by various known brake actuation systems, including hydraulic systems. The seat actuation auxiliary brake system includes the lever and hydraulic system described below, as well as other components that will be apparent to those skilled in the art.

In one embodiment, the force-transmitting linkage is a chain that engages the teeth of an axially mounted one-way sprocket. In another embodiment, the force transfer connector is a cable that can be welded, soldered or threaded or secured to the single direction engagement means in many other possible ways, and thus, the present invention includes various combinations of force transfer connectors, single direction engagement means and axially mounted anti-rollback means, the adaptation of these separate components to the vehicle and the system of the present invention will be apparent to those skilled in the art, for example, standard clutch, gear or rack and pinion systems may be modified or improved for use in the system and vehicle of the present invention.

Referring to fig. 1, the wheelchair 15 includes a frame 40, a front steering wheel assembly including at least two pivoting steering wheels, such as steering wheel 8 connected by steering wheel shaft 35 to the bottom of footrest 23, and at least one rear wheel(s) mounted on shaft 66; at least one of the rear wheels is a drive wheel, such as rear drive wheel 18. A one-way engagement device 9 in the form of a rotating disk is axially mounted on the shaft 66 for engagement in the manner described below in the discussion of fig. 4 and 5. The seat 20 with the armrest 30 is mounted on wheels 47 to slide along rails 45 on top of the frame 40. Brake lever 50 is pivotally mounted to frame 40 at pivot point 57 and is coupled at its top end by spring 55 to link 52, link 52 being affixed to the bottom of seat 20, brake lever 50 having brake pad 60 rotatably affixed at its bottom end for engagement with rear drive wheel 18. Thus, when the seat 20 is displaced forward during downhill movement, the brake lever 50 pivots, bringing the brake pad 60 into contact with the drive wheel 18. The adjustable footrest 23 is positioned horizontally within the frame 40 and is connected to the front steering axle 35.

The wheelchair has a control assembly including a control lever assembly 10, which control lever assembly 10 is mounted to frame 40 near footrest 23 by a rotational connection with a pivot 25 mounted to frame 40 (more details of control lever assembly 10 are described below in the discussion of fig. 2). As shown in fig. 1, control lever assembly 10 includes a steering column 1 and a sleeve 2, and is connected to a force-transmitting linkage 3 (which is a cable in fig. 1), and control lever assembly 10 is secured by a pivot 25 to pivot in forward and rearward directions. The steering column 1 is arranged to move within the control lever assembly 10, as discussed below in the description of fig. 2, the steering column 1 being flexibly secured at its bottom end to the front steering wheel shaft 35 by a flexible joint or universal joint, the flexible connection of the steering column 1 to the front steering wheel shaft 35 enabling the steering column 1 to move within the control lever assembly 10 while still maintaining the connection to the front steering wheel 8. The sleeve 2 is arranged to move along the steering column 1 and can be affixed at different positions along the control lever assembly 10 by manipulation of the steering column 1 (as described in more detail below in the discussion of fig. 2). The force transfer coupling 3 engages at one end with the axially mounted one-way rotating disc 9 and at the other end with the sleeve 2, the axially mounted one-way rotating disc 9 being connected to the frame 40, the fastener 29, the spring 21 and the fastener 27, the fasteners 27 and 29 being any standard fastening means such as screws, bolts, welds or clamps.

By manipulating the steering column 1 to push or pull the control lever assembly 10, the wheelchair occupant is able to steer, brake and propel the wheelchair 15. Steering column 1 can be manipulated to move sleeve 2, and thus force transfer link 3, along control lever assembly 10, engaging sleeve 2 and force transfer link 3 at different locations along control lever assembly 10. When steering column 1 is adjusted to lock sleeve 2 in a position relatively close to pivot 25 along control lever assembly 10, an increased propulsive force is applied by force transfer linkage 3 to drive wheel shaft 66 through single direction rotating disc 9.

Referring to fig. 2, the control lever assembly 10 has a plurality of slotted holes 11 extending along the length of the control lever assembly 10, the control lever assembly 10 being secured at its bottom end to a pivot 25, the pivot 25 including a lever pivot 5, the lever pivot 5 enabling the control lever assembly 10 to pivot in forward and rearward directions. (pivot 25 is mounted on frame 40 proximate footrest 23 shown in fig. 1.) in fig. 2, sleeve 2 is arranged to move over the exterior of control lever assembly 10, sleeve 2 having a plurality of slotted holes that extend along the length of sleeve 2 and may be positioned to overlap one or more of slotted holes 11 of control lever assembly 10. In fig. 2, each hole on the sleeve 2 overlaps a corresponding hole 11 of the control lever assembly 10.

A force-transmitting coupling member 3 in the form of a cable is secured to a clamping member 4, which clamping member 4 is in turn secured to the bottom outer surface of the casing 2. Grip 33 is affixed to the top exterior surface of sleeve 2 and frictionally engages the exterior surface of control lever assembly 10 during movement of sleeve 2 along control lever assembly 10, thus grip 33 prevents slippage of sleeve 2 that could cause failure of sleeve 2 and control lever assembly 10 engaged in the manner described below.

Steering column 1 has a locating pin 7 extending horizontally from its outer surface, and by movement of steering column 1, locating pin 7 can be positioned to simultaneously engage the slotted holes of sleeve 2 and control lever assembly 10, thereby locking sleeve 2 in a fixed position along control lever assembly 10. When a wheelchair occupant depresses steering column 1 to engage sleeve 2 and control lever assembly 10 at a position closest to the footrest, i.e., closest to pivot 25, the maximum propulsive and anti-rollback forces, which are equal to a mechanical advantage of ten or more times greater, are transferred by force-transmitting linkage 3 through the axially mounted one-way engagement means. The steering column 1 engages a steering wheel shaft 35 for steering by connection of a flexible joint or universal joint 37.

Referring to FIG. 3, when control lever assembly 10 is pulled rearward from a vertical orientation by pivoting at pivot 25, it actuates brake actuation device 44 such that brake 41 engages brake disc 49, thereby applying a braking force to rear drive wheel shaft 66. In the critical period of downhill movement, the passenger has two complementary braking systems at his discretion, neither of which requires hand movement from one device to the other, but instead, the passenger can steer and brake by manipulating the steering column 1 and thus the control lever assembly 10. If desired, the seat 20 is displaced forward to activate the auxiliary braking system previously described in the discussion of FIG. 1 to apply an auxiliary braking force.

Referring to fig. 4, the rear drive axle 66 is secured for rotation relative to the frame 40 by an axle fastener 99, the rear drive wheel 18 is axially mounted on the rear drive axle 66, the seat frame 72 is affixed to the frame 40, and the anti-rollback locking pin 70 extends through an aperture in the seat frame 72 to engage and disengage the aperture 74 of the circumferentially open anti-rollback apparatus 68. The single direction rotating disc 9 is axially mounted on a shaft 66 and comprises an axially engaging ratchet 62 and a pawl 64, the pawl 64 engaging ratchet 62 to ensure single direction rotation. Ratchet 62 and pawl 64 are mounted to engage on the outer surface of single direction rotating disk 9, and force transfer link 3 is also affixed to the outwardly facing portion of single direction rotating disk 9 by pin 77. Spring 21 is secured at one end to frame 40 by fastener 27 and at the other end to single direction rotating disc 9 by fastener 29, so that, during the forward advance stroke of control lever assembly 10 shown in fig. 3, force transfer link 3 and spring 21 are attached to single direction rotating disc 9 and the engagement of ratchet 62 with pawl 64 enables single direction rotating disc 9 to rotate to a certain extent in a single direction. During this forward propulsion stroke, the propulsion force transmitted through the force transmission link 3 is transferred to the drive wheel shaft 66 through the ratchet 62, and the vehicle incrementally (incementally) moves forward.

In normal anti-rollback mode operation, anti-rollback locking pin 70 engages a hole 74 in anti-rollback apparatus 68, and anti-rollback apparatus 68 inhibits rollback through resistive engagement with shaft 66. When unidirectional movement is set by engagement of the pawl 64 with the ratchet 62, the unidirectional rotary disc 9 also enhances the anti-rollback action by its engagement with the shaft 66 and its resistance to movement in the rearward direction.

Fig. 5 shows the anti-rollback member of fig. 4 in relation to an anti-rollback disengagement system including anti-rollback disengagement handle 102. Anti-rollback disengagement handle 102 has a grip 100 on its top end, anti-rollback disengagement handle 102 is pivotally mounted to frame 40 or control lever assembly 10 (not shown in fig. 5) at pivot point 103, anti-rollback disengagement handle 102 is also engaged to frame 40 by return spring 91. The disengagement cable 79 is affixed at one end to the bottom of the anti-rollback disengagement handle 102; the disengagement cable 79 is divided into (1) a pawl disengagement cable 83 secured to the pawl 64 by a securing pin 85 and (2) a rollback prevention disengagement cable 81 secured to a disengagement bar 87, the disengagement bar 87 engaging and disengaging the locking pin 70.

As shown in fig. 6, anti-rollback disengagement handle 102 is normally locked in an upright position by locking tab (tab)89 mounted on frame 40 or control lever assembly 10 (neither of which are shown in fig. 6) such that a pulling force is exerted on return spring 91 affixed to frame 40. Releasing the handle 102 from the tab 89 and pulling the handle 102 back pulls the release cable 79 with the following result. Referring to FIG. 5, when the handle 102 is disengaged from the tab 89 (FIG. 6) and pulled rearward, it pulls the release cable 79, and the release cable 79 disengages the pin 85 from the pawl 64, allowing the pawl 64 to disengage from the ratchet 62. Pulling the handle 102 rearwardly also pulls the rod 87 to disengage the locking pin 70 from the aperture 74 in the anti-rollback apparatus 68. This mode of operation allows rollback to facilitate selective rearward movement in situations where temporary disengagement of the anti-rollback apparatus is desired, such as where a wheelchair occupant maneuvers the wheelchair up and down an elevator. Moreover, it allows the occupant to selectively adjust the propulsive force transmitted through the control assembly to optimize the vehicle's movement pattern.

Referring to fig. 7, the seat 20 with wheels 47 is connected by a link 52 to a hydraulically assisted brake actuation device 122 (the installation of the seat 20 with wheels 47 has been previously described in the discussion of fig. 1). Sliding seat 20 forward activates brake actuation device 122, engaging brake disc 49 with the engaged shaft 66. Fig. 7 also shows hydraulic actuation of brake actuation device 44 by movement of control lever assembly 10, and the resulting engagement of hydraulic auxiliary brake actuation device 121 with brake disc 49 to apply a braking force to shaft 66.

In the illustrative embodiment shown in fig. 8, anti-rollback disengagement handle 102, having pivot point 103, is hydraulically connected to hydraulic cylinders 137 and 139 by actuator 133 and hydraulic link 135. Actuation of cylinder 137 disengages locking pin 70 from the anti-rollback apparatus, such as anti-rollback apparatus 68 shown in fig. 5, and actuation of cylinder 139 disengages pawl 64 from engagement with a ratchet, such as ratchet 62 shown in fig. 5, so that the system shown in fig. 8 provides an alternative to hydraulic actuation for the cable anti-rollback disengagement system shown in fig. 5.

Fig. 9 shows another embodiment, in which the force-transmitting linkage 3 is in the form of a rigid rod connected to a one-way engagement means 97 in the form of a one-way ratchet, the ratchet 97 engaging the shaft 66. Through the one-way engagement means 97 in the form of a one-way ratchet, a propulsive force is applied by the force transmitting linkage 3 in the form of a rigid rod to the drive axle 66 in the manner described previously in the discussion of figure 1.

Claims (18)

1. A propulsion, braking and steering control assembly for mounting on a manually propelled vehicle, the vehicle comprising: a frame; a front steering wheel assembly having at least two pivotable steering wheels with front steering wheel axles; a rear drive wheel assembly including at least one drive wheel mounted for rotation on a rear drive wheel axle; a one-way clutch axially mounted on the rear drive axle to transfer propulsive force; the anti-back-rolling device is axially arranged on the back driving wheel shaft and is axially arranged on a brake disc arranged on the back driving wheel shaft, and the front steering wheel component and the back driving wheel component support the frame and can enable the vehicle to move; a footrest located within the frame above the front steering wheel assembly, the front steering wheel shaft being pivotally attached to the frame below the footrest; a seat constructed and oriented to support a passenger, the seat being mounted for limited horizontal sliding movement on the frame by means of a roller and rail or linear bearing arrangement; a control assembly for propulsion, braking and steering, the control assembly comprising:

(a) a control lever assembly pivotally mounted to the top of the footrest having a plurality of engagement points extending along the length thereof, the control lever assembly being connected to the brake disc by a brake actuating member;

(b) a sleeve arranged to move over the exterior of the control lever assembly, the sleeve having a plurality of engagement points extending along the length of the sleeve, the engagement points being positionable to overlap one or more of the engagement points of the control lever assembly;

(c) a force transmitting connector affixed at one end to the sleeve and affixed at the other end to the one-way engagement means; and

(d) a rotating steering column extending through and arranged to move within the control lever assembly and which (i) engages and turns one of the front steering wheels by being connected to the front steering wheel axle by a flexible joint, and (ii) has an engagement member which, by movement of the steering column, can be positioned to simultaneously engage the engagement points of the sleeve and the control lever assembly, thereby locking the sleeve in a fixed position along the control lever assembly, wherein:

(1) by pushing the control lever assembly forward from the upright position when the steering column is adjusted to lock the sleeve along the control lever assembly at a position relatively close to the pivot mounted near the footrest, increased propulsive force is transferred from the force transmitting linkage through the one-way engagement means to the rear drive wheel shaft,

(2) pulling the control rod assembly in a rearward direction from a vertical orientation applies a braking force to the drive axle and

(3) during propulsion or braking, the vehicle can be steered by movement of the steering column.

2. The control assembly of claim 1, wherein the control lever assembly engagement point and the bushing engagement point are slotted holes and the steering column engagement member is a pin extending horizontally from an exterior of the steering column.

3. The control assembly of claim 2, wherein the force-transmitting linkage is a rigid rod, cable, or chain.

4. A control assembly as claimed in claim 1, wherein the anti-rollback apparatus comprises a circumferentially apertured disc mounted on the rear drive wheel shaft, wherein the disc is held in position by insertion of a locking pin through one of the apertures, the locking pin being mounted on a support for insertion into and withdrawal from the aperture, the support being fast to the vehicle frame.

5. The control assembly of claim 1, further comprising a grip portion at a top portion of the outer surface of the sleeve, the grip portion compressively engaging the outer surface of both the sleeve and the control lever assembly to prevent the sleeve from sliding as the sleeve moves along the control lever assembly.

6. The control assembly of claim 1, wherein the brake actuating member is a hydraulically actuated member.

7. A manually propelled vehicle comprising:

a frame; a front steering wheel assembly having at least two pivotable steering wheels with steering wheel shafts; a rear drive wheel assembly including at least one drive wheel mounted for rotation on a rear drive wheel axle; a one-way clutch axially mounted on the rear drive axle to transfer propulsive force; an anti-rollback apparatus axially mounted for engagement on the rear drive axle; an axially mounted brake disc mounted on the rear drive wheel shaft, said front steering wheel assembly and rear drive wheel assembly supporting said frame and enabling movement of the vehicle; a footrest located within the frame above the front steering wheel assembly, the front steering wheel shaft being pivotally attached to the frame below the footrest; a seat constructed and oriented to support a passenger, the seat being mounted for limited horizontal sliding movement on the frame; an auxiliary braking system activated by sliding the seat along the frame, said auxiliary braking system comprising a lever pivotally mounted on the frame, the lever being flexibly engaged to the bottom of the seat such that forward movement of the seat along the frame causes the lever to pivot and engage or disengage contact between a brake pad rotatably mounted on the bottom of the lever and the rear drive wheel; and a control assembly, the control assembly comprising:

(a) a control lever assembly pivotally mounted to the frame adjacent the footrest and having a plurality of engagement points extending along the length thereof, the control lever assembly being connected by a brake actuating member to a rear drive wheel braking mechanism which engages the rear drive wheel shaft for braking;

(b) a sleeve arranged to move over the exterior of the control lever assembly, the sleeve having a plurality of engagement points extending along the length of the sleeve, the engagement points being positionable to overlap one or more of the engagement points of the control lever assembly;

(c) a force transmitting connector affixed at one end to the sleeve and affixed at the other end to the one-way engagement means; and

(d) a rotating steering column extending through and arranged to move within the control lever assembly and which (i) engages and turns one of the front steering wheels by being connected to the front drive axle by a flexible joint, and (ii) has an engagement member which, by movement of the steering column, can be positioned to simultaneously engage an engagement point of the sleeve and the control lever assembly, thereby locking the sleeve in a fixed position along the control lever assembly, wherein:

(1) by pushing the control lever assembly forward from the upright position when the steering column is adjusted to lock the sleeve at a position along the control lever assembly relatively close to the pivot shaft mounted adjacent the footrest, increased propulsive force is transferred from the force transmitting linkage through the one-way engagement means to the rear drive wheel shaft,

(2) pulling the control lever assembly in a rearward direction from a vertical orientation applies a braking force to the drive axle, an

(3) During propulsion or braking, the vehicle can be steered by movement of the steering column.

8. The vehicle of claim 7, wherein the vehicle is a wheelchair, the control lever assembly engagement point and the bushing engagement point are slotted holes, the seat is affixed to the frame by wheels fastened on a bottom of the seat, the wheels are mounted on a top of the frame for horizontal movement along the track, the steering column engagement member is a pin extending horizontally from an exterior of the steering column, the unidirectional engagement device is a unidirectional rotating disk having a clutch and a pawl affixed to an outer surface of the disk, the clutch is axially mounted for engagement with the rear drive wheel shaft, the pawl engages the clutch to ensure unidirectional rotation by the disk.

9. The vehicle of claim 8, wherein the force-transferring coupling is a cable, wire, chain, or rigid rod.

10. The vehicle of claim 9 wherein the anti-rollback apparatus comprises a circumferentially apertured disc mounted on the rear drive wheel shaft, the disc being held in place by insertion of a locking pin through one of the apertures, the locking pin being inserted into and withdrawn from the aperture by means of a support secured to the frame.

11. The vehicle of claim 10, wherein the control assembly further includes a grip portion atop the outer surface of the sleeve, the grip portion compressively engaging the outer surface of both the sleeve and the hand control lever assembly to prevent the sleeve from sliding as the sleeve moves along the hand control lever assembly.

12. The vehicle of claim 10, further comprising a system for selectively engaging and disengaging the anti-rollback apparatus and the one-way clutch, the system comprising:

(a) a disengagement handle pivotally mounted on said frame at a location convenient for engagement by a vehicle occupant, the handle being locked in an upright position relative to said frame by a locking tab mounted on the frame when not in use, said disengagement handle also being connected to the frame by a spring connected to a bottom portion of the handle; and

(b) a release cable connected at one end to the bottom of the release handle and at its other end divided to connect to two fasteners, the first of which is adapted to disengage or engage contact between the pawl and the clutch, the second of which is adapted to disengage or engage contact between the detent pin and the aperture in the anti-rollback apparatus,

wherein when the disengagement handle is disengaged from the locking tab, the handle can be pulled rearwardly to pull the release cable, thereby disengaging contact between the pawl and the clutch and disengaging and engaging contact between the locking pin and the aperture in the anti-rollback apparatus.

13. A manually propelled vehicle comprising:

a frame; a front steering wheel assembly having at least two pivotable steering wheels with steering wheel shafts; a rear drive wheel assembly including at least one drive wheel mounted for rotation on a rear drive wheel axle; a one-way clutch axially mounted on the rear drive axle to transfer propulsive force; an anti-rollback apparatus axially mounted for engagement on the rear drive axle; an axially mounted brake disc mounted on the rear drive wheel shaft, said front steering wheel assembly and rear drive wheel assembly supporting said frame and enabling movement of the vehicle; a footrest located within the frame above the front steering wheel assembly, the front steering wheel shaft being pivotally attached to the frame below the footrest; a seat constructed and oriented to support a passenger, the seat being mounted for limited horizontal sliding movement on the frame; an auxiliary braking system activated by sliding the seat along the frame, said auxiliary braking system comprising a hydraulic piston connected to an auxiliary brake disc mounted on the rear driving wheel, said piston actuating the auxiliary brake disc when the seat is slid forward; and a control assembly, the control assembly comprising:

(a) a control lever assembly pivotally mounted to the frame adjacent the footrest and having a plurality of engagement points extending along the length thereof, the control lever assembly being connected by a brake actuating member to a rear drive wheel braking mechanism which engages the rear drive wheel shaft for braking;

(b) a sleeve arranged to move over the exterior of the control lever assembly, the sleeve having a plurality of engagement points extending along the length of the sleeve, the engagement points being positionable to overlap one or more of the engagement points of the control lever assembly;

(c) a force transmitting connector affixed at one end to the sleeve and affixed at the other end to the one-way engagement means; and

(d) a rotating steering column extending through and arranged to move within the control lever assembly and which (i) engages and turns one of said front steering wheels by being connected to said front drive axle by a flexible joint, and (ii) has an engagement member which, by movement of the steering column, can be positioned to simultaneously engage the engagement points of the sleeve and the control lever assembly, thereby locking the sleeve in a fixed position along the control lever assembly, wherein,

(1) by pushing the control lever assembly forward from the upright position when the steering column is adjusted to lock the sleeve at a position along the control lever assembly relatively close to the pivot shaft mounted adjacent the footrest, increased propulsive force is transferred from the force transmitting linkage through the one-way engagement means to the rear drive wheel shaft,

(2) pulling the control rod assembly in a rearward direction from a vertical orientation applies a braking force to the drive axle and

(3) during propulsion or braking, the vehicle can be steered by movement of the steering column.

14. A manually propelled vehicle, comprising:

a frame; a front steering wheel assembly having at least two pivotable steering wheels with steering wheel shafts; a rear drive wheel assembly including at least one drive wheel mounted for rotation on a rear drive wheel axle; a one-way clutch axially mounted on the rear drive axle to transfer propulsive force; an anti-rollback apparatus axially mounted for engagement on the rear drive axle; an axially mounted brake disc mounted on the rear drive wheel shaft, said front steering wheel assembly and rear drive wheel assembly supporting said frame and enabling movement of the vehicle; a footrest horizontally positioned within the frame above the front steering wheel assembly, the front steering wheel shaft being pivotally attached to the frame below the footrest; a seat constructed and oriented to support a passenger, the seat being mounted for limited horizontal sliding movement on a frame of the vehicle, the vehicle further comprising:

(a) an auxiliary brake system that applies a braking force to the rear drive axle, the auxiliary brake system being activated when the seat slides forward along the frame,

(b) a control assembly that (i) transmits propulsion to a rear drive axle through a force transmission linkage when pushed forward, (ii) transmits braking force to a rear drive axle through a force transmission linkage when pulled rearward, and (iii) ensures steering to a steered axle, the control assembly comprising: (a) a control lever assembly pivotally mounted to the top of the footrest having a plurality of engagement points extending along the length thereof, the control lever assembly being connected to the brake disc by a brake actuating member; (b) a sleeve arranged to move over the exterior of the control lever assembly, the sleeve having a plurality of engagement points extending along the length of the sleeve, the engagement points being positionable to overlap one or more of the engagement points of the control lever assembly; (c) said force transmitting connector secured at one end thereof to the sleeve and at the other end thereof to said one-way engagement means; (d) a rotating steering column extending through and arranged to move within the control lever assembly and which (i) engages and turns one of the front steering wheels by being connected to the front steering wheel axle by a flexible joint, and (ii) has an engagement member which, by movement of the steering column, can be positioned to simultaneously engage the engagement points of the sleeve and the control lever assembly, thereby locking the sleeve in a fixed position along the control lever assembly, wherein: (1) when the steering column is adjusted to lock the sleeve at a position along the control lever assembly relatively close to the pivot shaft mounted near the footrest, increased propulsive force is transferred from the force transmitting linkage to the rear drive wheel shaft through the one-way engagement device by pushing the control lever assembly forward from the vertical position, (2) pulling the control lever assembly in a rearward direction from the vertical orientation applies a braking force to the drive wheel shaft, and (3) during propulsion or braking, the vehicle can be steered by movement of the steering column,

(c) an anti-rollback disengagement system mounted to the frame or the control assembly for selectively disengaging the one-way engagement device and the anti-rollback device.

15. The vehicle of claim 14, wherein the vehicle is a wheelchair and the auxiliary braking system and the anti-rollback disengagement system are hydraulically actuated.

16. The vehicle of claim 14, wherein the vehicle is a wheelchair, the auxiliary braking system is hydraulically actuated, and the force-transmitting linkage is a cable, wire, chain, or rigid rod.

17. The vehicle of claim 14, wherein the vehicle is a wheelchair, the auxiliary braking device includes a lever connected to the seat, the lever having a brake pad at a bottom end thereof for engagement with the rear drive wheel, and the control assembly device includes a cable force transmitting linkage.

18. The vehicle of claim 14, wherein:

(a) the one-way engagement means is a one-way rotating disc having a clutch mounted axially for engagement with the rear drive axle and pawls affixed to an outer surface of the disc, the pawls engaging the clutch to ensure one-way rotation by the disc; and

(b) the anti-rollback apparatus comprises a circumferentially apertured disc mounted on the rear drive wheel shaft and secured in position by insertion of a locking pin through one of the apertures, the locking pin being mounted on a support for insertion into and withdrawal from the aperture, the support being fast to the vehicle frame.