WO2008039196A1

WO2008039196A1 - Ergonomically improved rowing motion-propelled convertible wheelchair using retractible fifth wheel

Info

Publication number: WO2008039196A1
Application number: PCT/US2006/038014
Authority: WO
Inventors: Stephen A. Barker
Original assignee: Bayne, Christopher, J.
Priority date: 2006-09-29
Filing date: 2006-09-29
Publication date: 2008-04-03

Abstract

The present invention solves many of the problems for the wheelchair bound individual who wants an ergonomically sensible, convenient, yet powerful and stable wheelchair. The Trike's unique power source is provided by a rowing-type motion of the user rather than the less efficient 'hand rim' grip or wrist propulsion. The rowing motion significantly reduces the chances for repetitive stress injuries, like carpal tunnel. Furthermore, the rowing motion and movements, are designed to facilitate efficient propulsion and steering in combination, to be effected simultaneously. The rowing motion allows the user's full arm strength and full range of motion to assist in the powering of the vehicle. The wheelchair also has a retractable fifth or propulsion wheel that allows the chair to be used in a confined space without sacrificing performance.

Description

ERGONOWIICALLY IMPROVED ROWING MOTION-PROPELLED CONVERTIBLE WHEELCHAIR

USING RETRACTIBLE FIFTH WHEEL

Invented by Christopher John Bayne, Los Gatos, CA; Stephen A Barker, Sheridan, OR

REFERENCE TO PRIORITY DOCUMENTS

[001.] This Application claims priority under 35 USC §119(e) and all other applicable US and International laws to 60/721,779 to US Application, filed September 29, 2005 and entitled ERGONOMICALLY IMPROVED ROWING MOTION PROPELLED CONVERTIBLE WHEELCHAIR USING RETRACTIBLE FIFTH WHEEL, which is incorporated by reference for all purposes.

BACKGROUND

[002.] [0002.] Many of the existing hand-propelled wheelchairs designed for improved power efficiency do not account for certain repetitive motion injuries that are particularly problematic for the wheelchair-bound population. While power may be the focus of these devices, the potential damage to even the most hearty of those who use such devices is catastrophic to the mobility of the wheelchair-bound, should injuries even as innocuous as tendonitis. Such injuries are often overlooked in wheelchair design, because they are not so devastating to the mobility of an able- bodied person.

[0003.] Furthermore, wheelchairs designed for high-speed use, may not account for the day-to-day needs of the wheelchair-bound individual either with regard to comfort, ease of use, or maneuverability in small spaces such as restrooms, common carriers, and commercial offices. Thus, generally the more rugged or powerful the wheelchair, the less appropriate it is for convenient everyday use. Other vehicles, such as US Patent 6,352,274 (which is incorporated by reference for all purposes) to Brian Redman may be designed for certain-aspects of human-powered mechanical efficiency, but do not address the needs of the disabled, such as use in a confined space, and are therefore not appropriate for adaptation for use in a wheelchair.

[0004.] A regular wheelchair with only "hand rim" propulsion provides no mechanical advantage (MA) and are therefore it is hard work to propel long distances, and especially difficult up hill. It is also has the disadvantage that power is interrupted and energy is wasted every time the hand rim is gripped and released because the mechanism is not continuous. For many wheelchair users, to propel over long distances can be strenuous and stressful on the shoulders and wrists. Hand cycles are limited mainly to outdoor use because they lack maneuverability. [0005.] SUMMARY OF THE INVENTION

[0006.] The present invention, the TRIKE™, solves many of the problems for the wheelchair bound individual who wants an ergonomically sensible, convenient, yet powerful and stable wheelchair. The Trike's unique power source is provided by a rowing-type motion of the user rather than the less efficient "hand rim" grip or wrist propulsion. The rowing motion significantly reduces the chances for repetitive stress injuries, like carpal tunnel. Furthermore, the rowing motion and rowing movements, are designed to facilitate efficient propulsion and steering in combination, to be effected simultaneously. The rowing motion allows the user's full arm strength and various range(s) of motion to assist in the powering of the vehicle. Other advantages of the present invention are included in table 1 below:

[0007.] Table 1: Main Features and Benefits summary of the "Trike" Feature Benefit

[0008.] The propulsion system of the present invention is only one of the many innovative features that allow the user to convert the vehicle from a high-performance tricycle with improved center of gravity to highly-versatile wheelchair for everyday use. For example, the TRIKE™ may be converted, on the fly, from a three-wheeled vehicle to a more conventional four-wheeled chair with the power (rowing) handle stored in the interior of the chair with a retractable third wheel. [0009.] The "Trike" uses a rowing type action which is bio-mechanically better and does provide significant Mechanical Advantage (see calculations below). It also has a cyclical mechanism which lends itself to gearing. Cyclical mechanisms are "low impact" and therefore reduced risk of injury to joints and ligaments. [00010.] The present invention is a hand propelled vehicle which quickly and easily "transforms" from

TriCycle Mode (extended) into Wheelchair Mode (retracted). It also provides a significant "mechanical advantage" which means that the rider can enjoy traveling quickly and easily over considerable distances. Then upon reaching their destination and while remaining comfortably seated, can convert to wheelchair mode for the essential maneuverability inside a building, restroom, office or home

"Trike" performs these functions all in the same vehicle with no need to transfer.

[0011.] Although the present invention retains the "hand rim propulsion" as a secondary means of propulsion because of its maneuverability in confined spaces, its primary motive power is provided by the rider with a "rowing motion" with what's called the "Power Steering" assembly. The "rowing motion" is a more natural and is bio-mechanically more efficient, regardless of the rider's size and strength. The other big advantage of the rowing style is the "range of motion" which lends itself ideally to exploitation of mechanical advantage afforded by the basic simple lever principle

[0012.] The present invention has suspension that "tilts" into the corners, like a regular bicycle. This means that unlike a "tricycle" the rear wheels remain parallel, reducing rolling resistance and tire wear. The tilting suspension also means that stability is maintained at the regular seat height of 20" which facilitates ease of "transfer" and increased visibility for and of the rider.

[0013.] The present invention may be used for exercise to maintain cardiovascular fitness which is essential to good health and well being and is particularly important for wheelchair users, since a user is able to combine exercise with the mobility needs. For this reason the present invention combines the bio-mechanical efficiency with simple mechanical advantage resulting in easier propulsion with versatility and practicality to provide the rider with fun, exercise and convenience combined.

[0014.] Embodiments of present invention may be configured to different end uses in various models will become available to suit many different types of users. For example, for the rider who wants the

"Deluxe" version there imay be a 7-speed (or higher) speed gearing and all the optional extras included; for the everyday user the "Standard" version is made without gearing and reasonably light weight; for the enthusiast, who just wants to go very fast, the light weight model which does not transform to "wheelchair configuration".

[0015.] BRIEF DESCRIPTION OF THE DRAWINGS

[0016.]

FIG. 1 illustrates in the component systems of particular embodiments of the invention;

FlG. 1 B illustrates the linear footprint of the retractable and extendible modes;

FIG. 1C illustrates the "rotational footprint" of the retractable and extendible modes;

FIG. 2A illustrates a first embodiment of the invention in extended mode from a side view;

FIG. 2B illustrates a first embodiment of the invention in extended mode from a top view;

FIG. 2C illustrates a first embodiment of the invention in extended mode from an underside view; FIG. 2D illustrates

FIG. 3A illustrates a first embodiment of the invention in extended mode from the front view;

FIG. 3B illustrates a first embodiment of the invention in extended mode from the rear view;

FIG. 4A illustrates a first embodiment of the invention in a retracted mode from a side view;

FIG. 4B illustrates a first embodiment of the invention in a retracted mode from a top view;

FIG. 4C illustrates a first embodiment of the invention in a retracted mode from a underside view;

FIG. 5A illustrates a first embodiment of the invention in a retracted mode from a front view;

FIG. 5B illustrates a first embodiment of the invention in a retracted mode from a rear view;

FIG. 6A illustrates the details of a propulsion system

FIG. 6B illustrates the details of the propulsion system

FIG. 6C illustrates the details of the propulsion system or drive from the underside;

FIG. 6D illustrates the operation of the propulsion system in a first embodiment;

FIG. 7A illustrates an embodiment of the hand-propelled vehicle in transition before extension;

FIG. 7B illustrates an embodiment of the hand-propelled vehicle in transition to extension mode;

FIG. 8A illustrates features of the suspension system of an embodiment of the hand-propelled vehicle from a rear view;

FIG. 8B illustrates optional features of the suspension system of a first embodiment;

FIG. 8C illustrates the features of the suspension system from a front angled view;

FIG 8D, illustrates the principle of the tilting independent suspension for each wheel in a sample embodiment;

FIG. 9A illustrates the detail of the differential gear and axle features for a first embodiment from a rear view;

FIG. 9B illustrates the detail of the differential gear and axie features for a first embodiment from a angled view;

FIG. 1 OA illustrates how a brake may operate in an embodiment;

FIG. 10B illustrates details of a roller brake as it may be implemented in particular embodiments of the invention;

FIG. 11A illustrates a second embodiment of the invention in full extension mode;

FIG. 11 B shows the second embodiment of the invention from a side view;

FIG. 12A illustrates the components of a second embodiment of the invention from a frontal view;

FIG. 12B illustrates the components of the second embodiment from a rear view;

FIG. 13A illustrates details of the components of the propulsion and clutch system of second embodiment;;

FIG. 13B further illustrates the details of the propulsion and clutch system; FIG. 14 illustrates the details of the rear portion of the rolling and securing mechanism for the retraction mechanism;

FIG. 15A shows an alternate embodiment of the hand-propelled vehicle in a retraction mode; FIG. 15B illustrates a side angle view of an alternate embodiment of the hand-propelled vehicle; FIG. 16 illustrates the details of the present invention from the rear view, including many features of the safety and suspension system; and

FIG. 17 illustrates detail of an alternate configuration of a braking system, [0017.] DETAILED DESCRIPTION OF THE DRAWINGS

[0018.] Figs 1A and 1B illustrate general conceptual groups of the components systems of several configurations of the present invention as it may be understood in terms of "systems." ►I. Propulsion System 100 (indices 101-199) Handlebar 113 T-bar 112

First prop elbow 115 Second prop elbow 117

Gear system 101 uses free wheels gears and idler sprokets Protective cover 998 Gear 120 First Axle 120(ax)

Drive Chain 1 122 (connects gears VT) Drive Chain 2 124 (connects gears 1/3) Drive Chain 3 126 (connects gears 2/3) Gear 130 Drive Chain Second Axle 130(ax) Main Gearing 140 (7-speed hub gear) Output sprocket 145 Drive Chain 155 Differential Gear 160(a/b)

II. Frame and retractable telescope and supports 200 (indices 201-299)

HA. Telescoping tube 230 Inner telescoping part 230(i) Outer telescoping part 230(o) Locking pin 232 HB. Frames from retractable wheels Jockey H frame 235 Jockey H frame foot rest 235(fr) III. Steering and Braking systems 300 (indices 300-399);

IHA: Steering 301-349 Cable 301

Steering knuckle 302 Cable Guide 305 Steering halo 307 Cable guide 305

IHB Braking 350-399 Braking handle 351 Bearing brakes 355 Braking cable 353 (not shown) IV Seat and sitting features 400 (indices 401-499); V. Wheels 500 (indices 501-599); Front wheel (extended 505(e) Front wheel retracted 505(r) Front wheel axle 505(ax) Rear wheels 510(a/b) Rear wheel axles 510(a(ax))/510(b(ax) Quick-release hubs 512(a/b) Drive shafts 515(a/b) Jockey wheels 597 and brackets 595 Vl Shocks and Suspension 600 (indices 601-699) 620 Shocks

Independent suspension a frame 602/605(a/b)

[0019.] Each one of the "systems" includes features that may be understood by skilled artisans to have its own innovative implementations that are independent of embodiments of the hand-propelled vehicle as a whole. Thus, skilled artisans should understand that not only does the TRIKE™ contain innovative features as a whole, but includes innovative components and configurations that may be applied to other human-powered vehicles or even partially human-powered vehicles. For example, the telescoping support frame may be thought of as an invention that may be applied to conventional wheelchairs as well as the hand-propelled vehicles discussed herein. [0020.] FIG. 1B illustrates the benefit of the retractable and extension feature of the hand-propelled vehicle from a linear or "wheelbase" perspective. Although, once again, the retractable/extendible feature should be thought of as both part of the hand-propelled vehicle and as an application that may be applied to conventional wheelchairs as well. FIG. 1C illustrates the advantage of having the "rotational" footprint, as wheelchairs need to operate in three-dimensional space, and the ability of a wheelchair user to reduce the rotational footprint in a small space by converting from the extended "travel" mode to the indoor "retracted" mode provides for a great degree of versatility for the wheelchair bound individual.

[0021.] Referring now to FIGS. 2A-2C, side, top and underside views of the 'extended' mode of a first embodiment of the invention are shown. Figs. 2a-2c illustrate the first embodiment from side, top and underside views respectively in an "extended" mode. The "retracted" mode of the first embodiment is shown in Figs. 4a-5c below. The convertible hand-propelled wheelchair is supported on a frame system 200, of which the primary structure is a telescoping support tube or frame 230, that has an outer portion 230(o) and an inner portion 230(i), which is "lockable" in either an extended or retracted position by a pin 232, which can take a variety of securing structures without departing from the scope of the invention. The telescoping support tube 230, supports a jockey frame, or jockey H frame 235 is configured such that it supports the jockeys wheels (597(a)/b) when the hand-propelled vehicle is in a retracted mode, and allows the user to rest their feet comfortably the vehicle is in an extended position, The telescoping support tube 230 also provides structural support for the fifth wheel forks 245 which operatively support the front or fifth wheel 505(e) and its axle 505(ax). [0022.] Figs. 2a-2c illustrate the innovative hand-propelled propulsion system 100 in the first embodiment. A handle bar 113, designed for easy gripping moves a "t-bar" or t-handle 112 propulsion lever or drive. The t-handle 112 moves forward and backward (indicated by z+ (front of the trike) and z- (rear of the trike)) with a slight arc (indicated by the theta+ or theta -,), but can vary based on the needs of the end user. The t-handle moves a first prop elbow 115, that also serves as a steering rotation around a plane. A cable (not shown) which extends from cable link structure 305 allows the t-handle 112 to turn the front wheel 505(e) at the steering knuckle 302. A two-way gear system 101 include a three gear configuration that allows the propulsion handle 112 to create forward motion by both the pushing and pulling motion.

[0023.] Fig. 2b shows a top view of the extended first embodiment, illustrates how a user turns the handle bars 113, so that the t-bar 112 is moved around an axis formed by the XZ plane (the rotations indicated by a phi(+) phi(-)) to steer the first embodiment of the hand-propelled. The cable guide 305 allows a standard bicycle cable to steer the fifth wheel 505(e).

[OO24.]Fig. 2c illustrates the underside of the first embodiment, which more clearly details the gear system of the propulsion system 101. The second prop elbow 117 drives the first gear 120 when the propulsion handle 112 is moved both forward and backward. The propulsion system is discussed further in Figs 6a-d below. Figs. 2d and 2e provide additional views of a first embodiment in an extended position.

[0025.] Fig. 3A provides a front view of a first embodiment in an extended position. In Fig. 3a, it is clear that the jockey wheels 597(a/b) are off the surface of the ground a few inches. Additionally the steering knuckle 302 for the fifth retractable wheel can be seen. There may be several mechanisms by which the TRIKE may be efficiently and safely turned along the fifth wheel pivot 307. [OO26.]Fig. 3b provides a rear view of the first embodiment of the invention and many of the suspension and support features can be seen. The independent suspension system 600 and the differential gearing 160a/b allow for the hand-propelled vehicle to be safely used in high-performance racing and made with standardized parts. The shocks 620 also provide the rider with additional safety and comfort. The independent wheel suspension is also detailed in Figs 8a-d below. [0027.] Fig. 4a illustrates a first embodiment of the hand-propelled vehicle in a retracted mode. The jockey wheels 597(a/b)(down) touch the surface of the ground, and the fifth wheel is raised 505(r) a few inches off of the ground. The folding part 111 of the handlebar 113 folds into the t-bar 112, so that there is nothing in front of the wheelchair user. Fig. 4b illustrates a top view of the retracted mode of a first embodiment. Fig. 5A provides a front view of the retracted mode of the first embodiment and Fig. 5b provides a rear view of the retracted first embodiment.

[0028.] Referring now to FIGS. 6A-6C, a propulsion or drive system 100 is shown in a first embodiment from top angle, side and underside views. The propulsion system 100 allows the TRIKE to be powered by the rider by moving the propulsion handle in both the forward rotation θ(+) and the reverse rotation θ(-). The "rotation" is not a pure circular "arc" but rather an ergonomically designed movement in both the x and y planes that will resemble a natural "rowing motion." Although, in certain embodiments, pure linear (Z+/-) may be more desirable for certain aspects of physical therapy (such as arm or elbow rehabilitation) rather than ergonomic advantages. Thus, skilled artisans should understand that different motions of the hand-propulsion drive may be used without departing from the spirit and scope of the invention, The t-handle 112 drives the vehicle forward by The primary drive gear 140 drives the output sprocket 145 which is connected to the differential 160(a/b) by a drive chain, allowing the rear wheels to safely turn corners by moving at different speeds.

[0029.] FIG. 6D shows the propulsion system in operation, and also shows that particular embodiments of the hand-propelled vehicle may take advantage of the use of standard bicycle parts by using gearing which emulates that of cycling.

FIGS 7A and B show the hand-propelled vehicle being converted from retracted mode (7A) to extendible mode (7B). [0030.] FIGS. 8A-C shows features of the suspension and support system from the rear view of a first embodiment, including independent rear suspension, differential gearing (see Figs. 9A/B), independent drive shafts (See Figs. 9A/B) and roller brakes (see FIGS. 10A/B). Referring now to FIG 8D, a sample of the tilting independent suspension system for each of the rear wheels 510A/B is shown. FIG. 8D is a schematic of how the suspension system allows the rear wheels 51 OA/B to "tilt" into corners. A sample right turn is shown in FIG. 8D1, as the sample left turn is shown in FIG. 8D2 [0031.] Fig. 9A shows the differential gears 160a/b that allow the rear wheels of the cycle 510a/b to [0032.] Fig. 9b illustrates the differential gears 160a/b from a side view.

[0033.] Fig.10a illustrates the sample placement of a brake handle 351 in a first embodiment of the hand-propelled vehicle.

[0034.] Figs. 11A-17 refer to the alternate embodiment of the invention and the indices should be considered separately from the first embodiment discussed above. Referring now to FIGS. 11A and 11 B, two different views of a second embodiment of the inventive convertible wheelchair from front angle and side angles respectively are illustrated. The wheelchair 10 may be broken down into several set of components for the purposes of organization. The first set of components is the propulsion system 100', which include the propulsion handle 110, the propulsion latch 120, the propulsion pivot 125, the engagement arm 130, the primary gear and drive system 140, and the wheel gear 150.

[0035.] In the alternate embodiment, the foldable propulsion handle 110 is made up of several components, which include the top portion 112, a bottom or engagement portion 114 and a pivot 115. The top portion 112 includes a grip 113. The grip 113 also has features that are part of the clutch system 180 which is discussed below.

[0036.] In the alternate embodiment, the next set of components shown in FIGS. 11A and 11B is the retractable wheel and storage system 200, which includes the third or propulsion wheel 210 and the retraction and latch mechanism, usually in the form of a pin 255. Other features of the first embodiment are shown, which include two additional retractable stabilization wheels 297A and 297B, which are connected to the secondary stabilization bars 290A and 290B, respectively. [0037.] One of the features of the present invention include the main retractable arm 230 that is extended at an angle downward to create a lower center of gravity for the TRIKE™. The third wheel 210 is supported by the main retractable arm 230 (described below) which supports the third wheel at a downward slope (moving towards the front of the wheelchair) and includes a rotation pivot 235 in the arm for steering the wheelchair. The downward slope of the retractable arm 230 has important advantages. First, the chair has a lower center of gravity while being propelled by the rowing motion, which allows for greater control. Second, the downward slope of the retraction arm 230 allows the stabilization wheels 297A/B to move off of the ground (approximately 2 inches in a first embodiment) while the vehicle is being propelled by the rowing motion, allowing for reduced drag of the stabilization wheels.

[0038.] The main part of the retraction mechanism 250 is located in a housing or "diamond tube" 251 which is housed underneath the riding platform or seat support 401. The retraction mechanism 250 allows the main retractable arm 230 to slide into and out of the retractable housing 251, when the retraction pin 255 is removed by the rider. Other features of the retractable arm 230 and housing 251 are discussed in FIGS. A and B, below.

[0039.] In the alternate embodiment, the next set of components include the safety and suspension system 300, which include the braking system 310 and the suspension systems 320. The braking system 310 includes a braking lever 312, which may be located in several places on the TRIKE™, but is preferably located on the in the center of the TRIKE™, right underneath the seat 405, which allows the rider to pull the brake lever 312 with the force of their weight. In the first embodiment the brake shoes 314A and 314B engage a brake disc(s) 316A and 316B which are located on the interior of the individual axles 375A and 375B. The alternate braking system is detailed below in FIG. 17... -[0040.] Referring now to FIGS. 12A and 12B direct front and rear views of the second embodiment in the extended mode are shown. Other important features of the innovative wheelchair may be seen. [0041.] It is important to the second embodiment of the invention that when the retraction arm 230 is extended and the third wheel 210 is engaged that the support wheels 297A and 297B are off the ground approximately two inches. This can be seen more clearly in FIG. 1 B as well as FIG. 2A, discussed below. In general the third wheel 210 is slightly off center, to allow the propulsion gears to be activated and used in the center of the TRIKE™. Thus, the user's rowing is more efficient that if the third wheel 210 were located in the center and the propulsion was off center. However, to compensate for the slight off center position of the third wheel, the rear wheels 402A/B can be slight adjusted to compensate for the off-center positioning. This compensation is discussed at FIG. 16 below.

[0042.] FIG. 13A illustrates further detail of the propulsion system 100' in the second embodiment. As can be seen the gears are configured such that the front wheel derives power from both a forward and a return stroke of the propulsion arm 110.

[0043.] Referring to the alternate propulsion system shown in FIG. 13A and 13B, a detail view of the lever system as engaged by the rowing motion propulsion arm 110 is shown. In considering the propulsion system 100, the lever (see indexes 110 and 120) and gears (see indexes, 130, 140 and 150) ratios may vary from embodiment to embodiment depending on the needs of the end-user, however, in a particular embodiment, given an average riders ability to deliver 50lbs force at a rate of 44 cycles/min (1 push/pull = 1 cycle) x 4ft of lever travel/cycle = 176ft/min. This equates to 50 x 176 = 880/ft-pounds/min. For conversion to kilowatts we must multiply 880ft-pound/min by 0.0000226 which = 0.2 kilowatts. (200W). Given a constant output from the rider of 200W applied to the mechanical advantage of the Trike's propulsion mechanism we have the following result:-

[0044.] Mechanical Advantage is defined as MA = L-÷ E where:-

(L) = load output force; (E) = effort or applied force (l-|) = handle length of the lever above the fulcrum(l2) = shorter length of the lever below the fulcrum

Using the law of levers (I₁) ÷ (I2) E x li L x I₂

Hence L÷ E 0i) ^÷ (l2)

Trike Propulsion lever or arms (110) Leverage = ₂0" ÷ 4"

20" (I₁) and 4" (120) (I₂)

MA 5:1

Example:- Applied force = 50lbs

(E)

MA 5

Output force L = 50 x 5 =

250IbS [0045.] Applying the.work rate of 200W to the alternate Trike propulsion mechanism at a cycle rate of

44/min x the mechanical advantage of 5:1 this yields a constant output sufficient to travel at approx 8mph (20" wheel Diameter x π (3.14) = 62.8" circumference x 3 for the gear ratio of Large (140) to small sprocket (150) « 188" x 44 cycles/min = 8,290'/min = 690ft/min = 7.85 mph or approx 2x walking speed.).

[0046.] Referring now to FIGS. 13A and B, details of the alternate propulsion 100 and clutch systems 170 are shown. FIG. 13A illustrates a block diagram of how the clutch system 170 works. The clutch system 170 includes a clutch 175, is located on the handle 113 and is grip-activated (clutch) or thumb-activated (button) which "pulls" a cable 174 located in the interior of the propulsion handle 110, which pulls or lifts a pin 176 located at the bottom on the propulsion handle 110 which engages the rocker arm 135 which drives the second or drive lever 120. The clutch system 170 is also an important safety feature as the rider can choose to engage the clutch 170 when traveling at high speeds to slow the vehicle down with the rowing motion of the propulsion arm 110. [0047.] Also referring now to FIG. 13B₁ a detailed view of the alternate propulsion gear 140 can be seen. The drive arm 130 is connected to the propulsion gear 140 through a rotating catch 133. The details of how propulsion gear 140 may be configured will vary from embodiment depending on the end use requirements of the user. However, in a primary embodiment, the rotating catch 133 allows the propulsion gear 140 to generate forward motion when the drive lever 120 moves in either direction from the "push" and "pull" rowing motion of the user. In other embodiments of the invention, the clutch 175 may engage or disengage the catch 133 that drives the propulsion gear, allowing the user a different type of control provided by the rowing motion of the propulsion arm 110. [0048.] Referring now to FIG. 16 a reverse view of the interior of the alternate embodiment TRI KE™ is shown. The housing 251 of the retractable mechanism 250 has 4 slots 255A, B, C, D, which in a preferred embodiment that allow the extendible arm 230 to slide back into the housing 251 in the retracted mode. Discussed below, each wheel 402A and B has its own axle and suspension system (360A and B, respectively).

[0049.] FIG. 16 also shows the two base plates or gussets 350(1) and 350(2) support the structures that generally comprise the suspension system for each of the wheels (402A and B). These include the shock absorber systems for each wheel 360A and B, the upper axle suspension or tie rod sets (357A(1) and (2) and B(1) and (2), respectively), the lower axle suspension or bushes (355A and B, respectively), which are both attached to the axles support plates 372A and B, respectively. One of the important features of the innovative wheelchair is that the independent suspension for each rear wheel (402A/B) allows the rear wheels to "tilt" independently into the turns. This is illustrated in FIGS. 9A-C, which is discussed below.

[0050.] Also shown in FIG. 16 is the handle storage 352, in which the propulsion arm 110 can be folded and stored in the interior of the TRIKE™ and underneath the diamond tube 251. The handle 113 runs horizontally along the back of the wheelchair.

[0051.] The bushings 355A/B can be adjusted to compensate for the off-center position of the third wheel 210. Each bushing 355A/B has an adjustment arms 354A/B which allow for fine adjustment of each of the axles 375A/B, respectively. The bushing 355A/B adjustment is particularly important as the off-center placement of the drive wheel 210 to maintain the centrality of the user's propulsion force(s) requires a very slight adjustment.

[0052.] In the alternate embodiment, FIG. 14 illustrates the detail of the front part of the retraction arm 230 as it collapses into the retraction housing or diamond tube 251. The retraction arm 230 slides along small wheels 232(1), 232(2) and 232(3) which are housed inside brackets 233(1), 233(2), and 233(3), respectively.

[0053.] FIG. 5B illustrates further detail of the interior of the retraction mechanism 250 and housing 251. The housing 251 is generally referred to as the "diamond tube" in a preferred embodiment. The diamond tube 251 has at least two slots 282(1) and 282(2) in the rear portion of the tube 251. The slots 282(1 and 2) may be located on the same side, but in a preferred embodiment, the front slot 282(1) is located on top of the tube 251 and the rear slot is located on the bottom. When the retraction arm 230 is pushed back into the diamond tube, two or more wheels 253(1) and 253(2) attached to the rear of the retraction arm 230, roll along the inside of the tube 251 until they reach the respective slots 282(1) and 282(2). A teeter 285 rotates the front wheel 253(1) up into the top slot 282(1) and the rear wheel 253(2) down into the bottom slot 282(2), securing the retraction arm 230 into the diamond tube 251. [0054.] FIGS. 15A and 15B illustrate the alternate embodiment of invention in retraction mode from angle and side views respectively. An important feature of the present invention is that the third wheel 210 is lifted off the ground in the retracted mode and the two support wheels 297A and B touch the ground. In general the third wheel is lifted about 2 inches to provide easy turning and clearance, as the front edge of the third wheel 210 generally only protrudes a couple of inches beyond the users' feet, which rest on the heel plates 481(A) and 481(B).

[0055.] Referring now to FIG. 17, a detail of some of the alternate of the braking components is shown. A braking cable (not shown) is connected to the brake lever (not shown, 312 in FIG. 1A) at one end, and to the equalizer plate EP at the other end. The equalizer plate EP is located on the top of the diamond tube (not labeled). The braking cable pulls the equalizer plate EP which, in turn, pulls the cables (not shown) that are each connected to the respective brake shoes (not shown, 316A and B, in FIG. 1B). The braking components, such as the cable, the shoes, and the discs, may be standard high-performance bicycle components, which reduce the cost of the vehicle.

[0056.] The engagement portion of the propulsion handle 114 slides over the propulsion latch 120, such that the user can drive the vehicle by moving the top portion 112 of the handle back and forth in a "rowing motion." In various embodiments the "rowing motion" can be adjusted to the needs of the wheelchair users, but is generally a back and forth motion (discussed below) and extends a total of approximately 60 degrees in a preferred embodiment. This includes 30 degrees towards the user from the "normal" z-axis position and 30 degrees away from the user (See FIG. 11B). The engagement portion 114 may also include an optional pin or latch 117 which locks the propulsion handle 110 into place over the engagement arm 120, preventing slipping or the propulsion handle 110 from getting stuck on the engagement arm 120 during strenuous use of the TRIKE™. [0057.] The front wheel gear and axle 150 may have optional multiple gears (not shown), such as would be desirable for various activities in the chair, such as racing (high gear ratio), climbing hills (low gear ratio) or city use (medium gear ratio).

[0058.] An optional clutch system 170 is present in an alternate embodiment, through a hand-pulled lever or button 182 and located in the handle 113. The clutch system is described below in FIGS. 13A and 13B.

Claims

CLAIMSI claim:

1. A hand-propelled vehicle comprising: a frame with a telescoping support bar, said bar supporting a rider seat and wheel supports for five wheels, including two front jockey wheels, two rear wheels and a retractable front wheel; a rowing-motion propulsion system including a t-bar lever connected to an elbow, said t-bar moving in forward and reverse direction, said elbow driving a gear wheel when said t-bar is moved either forward or backward; said t-bar lever pivoting at a point on said telescoping support bar; said gear wheel driving said two back wheels; said t-bar being rotatable; wherein when said telescoping support bar is extended, said retractable front wheel is touching a road surface, and two front jockey wheels are lifted off of said surface.

2. The hand-propelled vehicle as recited in claim 1 , wherein when said telescoping support bar is retracted, said retractable front wheel is lifted off of said road surface and said front jockey wheel are lowered onto said surface.

3. The hand-propelled vehicle as recited in claim 1, wherein said frame includes a h-shaped jockey frame, wherein when said h-shaped jockey frame includes an extension that lowers said retractable wheel onto said surface, when said extension is pushed.

4. The hand-propelled vehicle as recited in claim 1, wherein said gear wheel is connected to a differential gear that is operatively connected to each of said two rear wheels.

5. The hand-propelled vehicle as recited in claim 1, wherein a brake lever is located on said handle bars, said brake lever connected to a brake cable for operating a brake, said brake connected to brake means for braking said rear wheel.

6. The hand-propelled vehicle as recited in claim 1, wherein said t-bar

7. The hand-propelled vehicle as recited in claim 1 , wherein said t-bar is connected

8. A hand-propelled vehicle, including: a frame supporting a front wheel and two rear wheels; a drive propulsion system in which a lever configured to move front to back to front driving an elbow across a fulcrum, said elbow moving a first gear that moves in rotation in only one direction and drives a second gear in one direction when lever is either moved forward or backward; said second gear connected to a drive gear; said drive gear propelling said vehicle forward.

9. The hand-propelled vehicle as recited in claim 8, wherein said front wheel is supported by a retractable telescoping bar, wherein said telescoping bar includes a sliding inner portion and a stationary outer portion , configured such that when said inner portion is at least partially retracted within said outer portion, said front wheel is lifted off the surface of the ground, wherein said inner portion may be locked into said extended or retractable positions.

10. The hand-propelled vehicle as recited in claim 9, further including two rotatable jockey wheels, said rotatable jockey wheels each connected to a frame, said rotatable jockey wheels configured to lower onto said surface when said inner portion of said telescoping bar is retracted, and raised off of said surface when said telescoping bar is extended.

11. The hand-propelled vehicle further including a fork supporting said front wheel, the top of said fork ending in a steering knuckle, said front wheel rotated by a steering said rotatable lever, said lever connected to a cable that rotates said front wheel in order to steer said hand-propelled vehicle.

12. The hand-propelled vehicle as recited in claim 8, further including a braking system, said braking system including a brake handle on said lever, said brake handle operating a brake cable, for operating a brake for braking said rear wheels.