O US005280936A United States Patent (19) 11) Patent Number: 5,280,936 Schmidlin (45) Date of Patent: Jan. 25, 1994

(54)54 SYSTEMHUMAN POWERED D WEHICLE AND DRIV E FOREIGN PATENT DOCUMENTS 76 Inventor: Dennis Schmidlin, 1002 W. College 2455540 l/1981 FranceaCe ...... 280/240/ Ave., Woodville, Ohio 43469 Primary Examiner-Margaret A. Focarino (21) Appl.1. No.: 56.4756,471 Assistant Examiner-Vitor E. Johnson (57) ABSTRACT (22 Filed: May 3, 1993 A two wheeled human powered vehicle, having a frame (51) Int. Cl* ...... B62M 1/12 with seating arrangement resembling a long wheelbase sits.ci..."20/326/44280/252 parallelrecumbent operating . lever The armsdrive supportingmechanism aincludes steering two as: 58) Field of Search ...... 280/230, 233,23,240, sembly on their upper end, fulcramed in the middle, and 280/242. 244, 246, 252,253, 255, 258, 263 operably connected at their lower end to a linearly ' ' ' " " " 's reciprocable footrest assembly. The operator forces the footrests forward directly with the legs while assisting (56) References Cited with the arms by drawing the handlebar, thereby pro U.S. PATENT DOCUMENTS viding a rowing motion that utilizes arm and leg power - independently. Linear motion is converted to rotational 3,769,905 9/1973 Power ...... 280/233 X motion and power is transferred to the drive wheel via E. 2. SE dez. .283%; a jackshaft, including an overrunning clutch, along with 4,508,358v was 4/1985 Erelendez ...... 280/234 a and an endless chain, operably connected to 4,632,414 12/1986 Ellefson ...... 280/246 the drive wheel. Steering is accomplished through flexi 4,639,007 1/1987 Lawrence ...... 280/234 ble sleeved cables, controllably connecting the handle 4,700,962 10/1987 Salmon ...... 20/20 bar to the front steering fork. 4,796,907 1/1989 Geller...... 286/20 4,928,986 5/1990 Carpenter ...... 280/234 17 Claims, 3 Drawing Sheets

U.S. Patent Jan. 25, 1994 Sheet 1 of 3 5,280,936

U.S. Patent Jan. 25, 1994 Sheet 2 of 3 5,280,936

U.S. Patent Jan. 25, 1994 Sheet 3 of 3 5,280,936

5,280,936 1. 2 offers a smooth ride and stability, in addition to HUMAN POWERED VEHICLE AND DRIVE good aerodynamics and ease in mounting or dis SYSTEM mounting. Further objects and advantages are to provide a vehi BACKGROUND-DISCUSSION OF PRIOR ART 5 cle that is highly adaptable to different drive train modi Many variations of human powered vehicles attempt fications, the simplest of which being a pedal crank for to independently combine arm and leg power. This is an use in hill climbing, to provide a vehicle which is adapt advantage for transportation purposes and also pro able to performance enhancers, such as spring biasing, a duces better overall exercise than is possible with pedal vehicle which is simple to use, inexpensive to manufac crank . The rowing motion is the most natural O ture, and uses standard bicycle components and after form for coordinating arm and leg power, but has never market products. been successfully incorporated into a genuinely practical Still further objects and advantages will be apparent land vehicle. after a consideration of the ensuing description and U.S. Pat. No. 4,632,414 discloses a three-wheeled drawings. land vehicle that does a good job of simulating rowing. 15 The same may be said for the vehicles disclosed in U.S. SUMMARY OF INVENTION Pat. Nos. 4,700,962 and 4,796,907. The vehicle of U.S. In accordance with the invention there is provided a Pat. No. 4,305,600 uses rowing motion on a simpler two-wheeled human powered vehicle with an im two-wheeled vehicle. Unfortunately, for all of these proved drive system, simulating a rowing motion, while vehicles, the arm and leg forces are not truly additive. 20 allowing the legs to drive the vehicle directly. On the All of the power delivered to the drive wheel must be upper end of a levering assemblage, a handlebar, which transferred through the arms, which fatigue quickly. is in steerable communication with the front wheel U.S. Pat. Nos. 4,928,986 and 4,508,358 disclose vehi through flexible sleeved cables, serves as the oar han cles that are two wheelers in at least one embodiment dles for the rowing device. Reciprocation of the handle and use arm and leg power independently. Unfortu 25 bar imparts a linear reciprocation of the footrest assem nately, they are encumbered by heavy, inefficient mech anisms resulting from essentially separate drive systems bly in the opposite direction. The leg and arm motions for the arms and legs. are coordinated in the optimum rowing form, with the All vehicles that have attempted to combine arm and accumulated force conveyed to the drive wheel via an leg power have proved too awkward in handling, and 30 overrunning clutch operatively connected to the drive too inefficient due to weight and complexity or poor wheel to effect a forward rotation thereof. conservation of kinetic energy. Most are also hindered DRAWING FIGURES by poor impedance matching between the operator and machine through less than optimum leverage, stroke In the drawings, closely related figures have the same amplitude, or gearing. 35 number but different alphabetic suffixes. Figures that It is well known that rowing is one of the best mo are identical but located on opposite sides of the vehicle tions for exercising all the major muscle groups. It is less are designated with an L suffix for left side and an R well known that this motion can produce more horse suffix for right side. power than that of turning a pedal crank; thereby, mak FIG. 1. Full length side view of preferred human ing the human body a more powerful engine for driving 40 powered vehicle embodiment. a vehicle. What has never before been created is a vehi FIG. 2. Isometric view detailing steering assembly, cle that can utilize this motion in a light weight, energy footrest assembly, drive mechanism, primary drive efficient system, while at the same time providing a train, and frame. comfortable body position and easy handling for an FIG. 3, Side view shows rear most position of steer overall superior Human Powered Vehicle. 45 ing assembly. FIG. 4. Side view shows simpler embodiment of main OBJECTS AND ADVANTAGES drive mechanism, pedal-crank embodiment, and seat Accordingly, several objects and advantages of my embodiment. invention are: FIG. 5. Isometric view of simplified drive mecha a) To provide a Human Powered Vehicle which 50 S. simulates the linear reciprocating motion of row FIG. 6. End view of steering assembly, illustrating ing, or sculling, with a sliding seat. steering cable stops and large diameter drum with b) To provide a drive mechanism that improves upon mounting technique. standard rowing by permitting the legs to drive the FIG. 7. Side view shows a second embodiment of the "oars' directly. This results in a type of "forced 55 fork assembly with steering method. rowing' that uses arm and leg power indepen dently. DESCRIPTION OF INVENTION c) To provide a human powered vehicle that exer A typical embodiment of the human powered vehicle cises every major muscle group to a high degree of of the present invention is illustrated in FIG. 1 and FIG. efficiency, through proper impedance matching 60 2. Referring to these two figures; The vehicle includes and a motion which feels ergonomically correct. a frame 10 comprising a front end 12 and a rear end 14, d) To provide a vehicle that is comfortable, allowing a right side 16, (not shown in left side views), and a left a panoramic view and easy handling characteris side 18. Frame 10 is symmetrical from left to right along tics. its longitudinal axis and resembles that of a long wheel e) To provide a narrow vehicle that is relatively safe 65 base, two wheeled recumbent bicycle, which is known in traffic. to the art. Frame construction may be of any suitable f) To provide a vehicle with a medium length wheel frame material but preferably of welded square cross base, and a medium low center of gravity which sectional steel tubing and of an 'A' framed, double 5,280,936 3 4. truss design as shown, providing a high degree of rigid ulated parallelogram of identical symmetry on each side ity to the frame structure. of drive mechanism 4.0. Steering assembly 34 forms the The top of frame 10 embodies a left and right footrest upper side of each parallelogram as shown in FIG. 2. assembly guide member (designated 20L and 20R). This double parallelogram configuration maintains sup Guide members 20 L&R support the main drive mecha port of steering assembly 34 at a more operable attitude nism 40 and are essential to the function of the linear with respect to the rider throughout the stroke of drive motion element of drive mechanism 40. mechanism 4.0. While not vital to the operation of the Guide members 20 L&R consist of a suitable material vehicle, this configuration increases comfort and en to guide footrest assembly guide rollers 22T, 22B, and hances steering control for the rider. 22C, and serve as structural support members as well. 10 FIGS. 4 and 5 illustrate an embodiment of drive The preferred embodiment utilizes square cross-sec mechanism 40 which does not include upper linkage tional stainless steel tubing in a parallel side-by-side members 36 L&R, or a "floating' steering assembly. configuration and is of welded construction to form an Another embodiment may utilize a cantilever steering integral part of the frame. and footrest assembly, supported by a monolevering FIG. 2 shows a left guide member 20L partially cut 15 assembly and be within the spirit and scope of this in away to detail a footrest assembly 24, comprised of vention. three solid pieces of aluminum or other lightweight The vehicle utilizes a standard 38 material such as plastic, of which the center piece con and a standard bicycle front fork assembly 42, as shown tains center guide rollers 22C. Footrest assembly 24 is in FIG.1. This permits the use of standard removeably joined together by bolting, to facilitate the 20 systems (not shown) and standard handlebar mounted removal of footrest assembly 24 from guide members 20 gear shifters, also not detailed as these components are L&R, and allow the disassembly of center rollers 22C well known to the art. from footrest assembly 24; center rollers 22C being held Handlebar 38 is attached to a steering column or shaft in place by axles, which are constrained by the top and 44 via a standard bicycle 39, modified to enable bottom portions of footrest assembly 24. Four top rol 25 fixedly mounting to shaft 44. Shaft 44 is rotatably lers 22T and four bottom rollers 22B are journaled from mounted in steering assembly 34, which is preferably footrest assembly 24 and all rollers are of a suitable composed of lightweight materials, such as aluminum of plastic material or steel ball bearing to permit footrest welded construction, and may utilize flanged bushings assembly 24 to guidedly roll in a linear reciprocating of a suitable bearing material, or ball bearings for shaft movement between guide members 20 L&R. 30 rotation. Also fixedly mounted on shaft 44 is a drum 46, Included on footrest assembly 24 are pivotally at which may take the form of a disk. Operably connecting tached pedals, or footrests 26L and 26R for placement steering assembly 34 to front fork assembly 42 are flexi of the rider's feet and receiving force from the rider's ble, sleeved cables 48, such as those used for motorcycle legs. clutch or brake control. Cables 48 are wrapped over Located below footrests 26 L&R on footrest assem 35 drum 46 and affixed to it. Cable sleeve stops 49 are part bly 24 are rigid linkage members 32L and 32R, (32R not of steering assembly 34 as detailed in FIG. 6. Cables 48 shown) pivotally attached at pivot 28, which transmit cross each other under steering assembly 34 with their force from the rider's arms to footrest assembly 24 via other ends being affixed at opposite sides of fork assem lever arms 30L and 30R. Linkage members 32L&R are bly 42, in such a manner that cable routing will not identical, and journaled from opposite sides of footrest interfere with the motion of drive mechanism 4.0. Ad assembly 24 on the same axis; thus, operate together as justable cable sleeve stops, 41L and 41R on frame 10, one unit. maintain tension on cables 48, thereby enabling steering Similarly, lever arms 3OL&R, along with upper link assembly 34 to impart rotation to fork assembly 42, in age members 36L and 3.6R, are also identical. Lever the same direction as handlebar 38 is turned. arms 3OL&R are bent forward at a predetermined angle 45 FIGS. 6 and 7 detail how a more rigid steering con below their fulcrum pivot 31 for clearance of other trol is accomplished using a larger diameter drum 46 on vehicle parts, as well as to enhance mechanical advan steering assembly 34 and a large diameter drum 45 on tage characteristics throughout the motion range of the fork assembly 42, allowing more leverage of cables 48 device. Lever arms 3OL&R function as a single lever on fork assembly 42. ing means, pivotally linked with and journaled on the 50 FIG. 1 shows a drive chain 50, removably connected same shaft 29 as linkage members 32 L&R. Best shown to footrest assembly 24 by a hooking device 52, being in FIGS. 2 and 3, shaft 29 extends across the width of affixed through a hole in footrest assembly 24. Drive drive mechanism 40 and contains a roller 33 in the cen chain 50 is traversed over an over-running clutch 54 and ter, Roller 33 rotates on the axis of shaft 29 and is made extends forward to be extensively affixed to the front of of a plastic or suitable material. Roller 33 acts as a 55 frame 10 via retracting spring 56. Overrunning clutch spacer to keep linkage members 32 L&R located prop 54 is fixedly mounted to a jack shaft 53 which is jour erly on shaft 29 and also reduces friction when shaft 29 naled from frame 10 on bearing blocks 58L and 58R. contacts drive chain 50 at the end of the drive stroke. (Right bearing block is not shown.) Jack shaft 53 also Lever arms 30 L&R are constructed of similar materi contains thereon a sprocket 60 which could be substi als as frame 20 and pivotally support a steering assembly tuted by a standard chainring cluster and transmission 34 in conjunction with upper linkage members 36 L&R. as would be used on the pedal crank of a standard bicy Members 36 L&R may be of lighter materials than lever cle. As illustrated in FIG. 1, sprocket 60 is fixedly lo arms 30 L&R. The pivots on steering assembly 34 are cated on jack shaft 53 to be in the same orientation with two sets of journals, projecting coaxially from opposite rear wheel 62 and transmission 64 as the orientation of sides of steering assembly 34 as are the pivots on left and 65 and wheels on standard bicycles. Rear wheel right guide members 20 L&R. Guide members 20 L&R, 62 and transmission 64 are mounted to frame 10, and together with the upper portions of lever arms 30 L&R sprocket 60 is driveably linked with rear transmission 64 and linkage members 36 L&R, form essentially an artic using endless chain 65, in the same manner as utilized on 5,280,936 5 6 standard bicycles. This provides the same gearing op foot on its corresponding footrest 26L or 26R. Rider tions to the vehicle of the present invention, as is possi then pulls back on handlebar 38 while bracing one foot ble with standard bicycle components, known to any on its footrest and "shoving off from the ground with one in the field. the other foot. Steering the vehicle is done simulta As shown in FIG. 2, the ends 57 of jackshaft 53 may neously with drawing the handlebar or "rowing". The extend through bearing blocks 58 and be formed to rider places the other foot on its footrest while main accept standard bicycle pedal crank arms, affixed by taining balance of the vehicle in a manner similar to the bolting in the standard way of better bicycles. FIG. 4 way starting is accomplished on a two wheeled recum illustrates an embodiment of the vehicle with crank bent bicycle with top steering. Stability is quickly arms 55 L&R, and pedals 59 L&R attached, establishing 10 achieved and the rider may begin up-shifting and accel essentially a standard bicycle foot pedal crank and drive erating with full rowing strokes. train conjoined with the drive train of drive mechanism The form and motion are essentially that of sculling 40. In this embodiment, the rider can stand to crank with a sliding seat, but they are derived in a different pedals, Bit and row? or coast, as desired. manner. Rather than the fixed footrests and sliding seat Also detailed in FIG. 4 is a simpler embodiment of 15 of a scull, seat 66 and backrest 68 are rigidly mounted to drive mechanism 40, as previously described, and an frame 10 while footrests 26 L&R slide (or roll) to obtain embodiment of seat 66 with no back rest. It should be the leg motion. The legs brace while the arms row, but noted that these embodiments may be incorporated with my drive system, this can be done in reverse, with together as a high performance version of the vehicle, the legs driving the "oars' directly. This allows the separately, or in any combination, 20 arms to do very little work if desired, aside from steer In the preferred embodiment of the vehicle, as illus ing the vehicle. The "oars' in this case being handlebar trated in FIG. 1 seat 66 and backrest 68 are separately 38 which is operably connected to drive mechanism 40, mounted to facilitate individual adjustment of each, or and steerably connected to the front fork via flexible the complete removal of backrest 68 while retaining sleeved cables 48. seat 66. Bolting seat 66 from underneath and bolting 25 It is natural for a rower to pull with the arms only backrest 68 from the sides accomplishes this. Backrest while pushing with the legs. Only the force applied support member 70 can be made of square cross-sec should be independent and infinitely variable for each, tional steel tubing, while seat and backrest cushions are to provide rest for the arms while still powering the upholstered board of suitable materials. A standard vehicle with the legs. recumbent bicycle seat well known to the art could be 30 Arm and leg power also complement each other substituted here. through the way the forces are vectored. The non-lin FIG. 3 illustrates with phantom lines a front footrest ear angle of force applied by linkage members 32 L&R assembly stop 72, and a rear stop 74. These stops are to footrest assembly 24 opposes the non-linear angle of located between guide members 20 L&R. Their purpose force applied by the legs. Force vectors are focused in is to limit the travel of footrest assembly 24 in either 35 a linear direction, parallel to the longitudinal axis of direction and cushion the stop. They are made of suit guide members 20 L&R. This results in very low fric able material such as rubber and are held in place by tional losses in the linear motion of footrest assembly 24. fitting tightly between guide members 20 L&R, and by Along with the doubling of the drive mechanism sym an adhesive. metrically on each side of the vehicle, the system yields From the description above, a number of advantages 40 very little energy loss from frame flex, low frictional of my human powered vehicle become evident: losses from side loading, and a smooth overall action. a) The vehicle has similar frame geometry as that of My vehicle addresses, conservation of energy in a a long wheelbase, two wheeled recumbent bicycle; number of ways. FIGS. 1 and 3 show the forward most a proven design for superior comfort, safety, and and rear most positions of handlebar 38. From the for handling characteristics, as well as very good aero 45 wardmost position, the riders arms have a high mechan dynamics. ical advantage enabling rapid acceleration of the mech b) The vehicle uses mostly standard bicycle or re anism and a smooth, early link-up with the drive train. cumbent bicycle components, available at many As the power stroke progresses, mechanical advantage parts outlets. w of the arms decreases to approximately the center of the c) The vehicle is adaptable to many standard after SO stroke where the rider's strength is greatest. Mechanical market products such as lights, horns, storage advantage then begins to increase again as the angle racks, , car racks, and stationary exercise between linkage members 32 L&R and lever arms 30 converting mechanisms. L&R straightens. From approximately the middle of the d) The vehicle is highly adaptable to different gearing power stroke, the velocity of the rider's arms begins to and drive train modifications. 55 increase. Approaching the end of the power stroke, the e) The main drive mechanism is extremely compact, upper part of drive mechanism 40 and the rider's arms lightweight, and efficient due to its small number of are moving relatively fast, producing more kinetic en moving parts. ergy. This is precisely the time roller 33 on pivot shaft f) The vehicle is easy and economical to manufacture. 29 contacts drive chain 50 and begins to deflect it, as 60 illustrated in FIGS. 2 and 3. OPERATION OF PREFERRED EMBODIMENT As drive chain 50 is deflected, the rider's arms and FIG. 1 illustrates the vehicle at rest with steering drive mechanism 40 are decelerated, transferring the assembly 34 in its most forward position. This offers kinetic energy to drive chain 50. This energy, along comfortable, easy mounting by a rider. At this time the with the high mechanical advantage available to the vehicle is shifted to a low gear for easy starting. In this 65 rider again at this point, provide a burst of power to be embodiment, there are no crank arms 55 L&R attached; delivered to the drive wheel at the end of the power therefore, the rider would sit on seat 66, grasp handle stroke. Additionally, the rider's strength is not wasted bar 38 with both hands, and place either left or right in decelerating the mechanism. 5,280,936 7 8 In the return (non-power) stroke, acceleration of Thus, the scope of the invention should be determined motion is aided by retracting Spring 56. The only work by the appended claims and their legal equivalents, done in the return stroke is that of compressing the legs. rather than by the examples given. Compression of the legs decelerates the system at end of What is claimed is: the return stroke, and energy is stored in the legs to be 5 1. A human powered vehicle comprising delivered in the next power stroke. a. a frame having a longitudinal axis and a seat for a A number of methods are available for biasing drive rider facing parallel to said longitudinal axis, mechanism 40 in the power stroke direction. This b. a steerable front wheel operably journaled on said would utilize the return stroke motion to store more frame and a rear drive wheel journaled from said energy for the driving the vehicle, and add heavier 10 frame including variable drive means for receiving bench-press and stomach crunch exercises to the vehi power to said drive wheel cle. c. a drive mechanism comprising footrests in front of Other methods of enhancing the mechanical advan said seat, mounted together on reciprocable linear tage of the device include: motion means whereby the motion of said footrests a) making lever arms, linkage members or footrests 15 is parallel to said longitudinal axis of said frame, adjustable. and a reciprocable hand operated levering means in b) changing the diameter of roller 33, position of harmony with said linear motion means, said lever pivot 28, or position of chain connection 52 to ing means pivoted on said frame and extending modify the deflection of drive chain 50. below said pivot, and having an upper end and a c) replace the round sprocket on overrunning clutch 20 lower end, said lower end of said levering means 54 and drive chain 50 with a grooved cam and pivotally connected by a rigid linkage member to cable similar to those used on overhead garage said footrest linear motion means whereby a recip doors. rocating rotational motion of said levering means Operation of the vehicle embodiment utilizing a pedal defines a reciprocating linear motion of said foot crank on jackshaft 53 would be the same except the 25 rests and vice-versa, said upper end of said levering rider would have the option to stand and pedal, as on a means including standard upright bicycle. This would aid in starting the d. a steering means in operative connection with said vehicle from a stopped position, or in climbing hills. steerable front wheel via flexible sleeved cables, Another option available with a pedal crank installed said steering means including thereon a handlebar, concerns tandem riding. If a second seat were posi- 30 wherein rotation of said handlebar effects steering tioned over rear wheel 62, a second tandem rider could the vehicle, and drawing said handlebar effects said pedal while the driver of the vehicle rows, with all rotational motion of said levering means, and said power being combined to drive the vehicle. Jack shaft linear motion of said footrests, thereby producing a 53 could be positioned forward in frame 10 to better power stroke, the power being transferred to said accommodate various pedal crank uses. A tandem seat 35 drive wheel through a could take the form of a storage rack with a cushion. e. drive train comprising an overrunning clutch, a jackshaft, and an elongated flexible drive means, SUMMARY, RAMIFICATIONS, AND SCOPE one end of which is attached to said linear motion Accordingly, the reader will see that the human pow portion of said drive mechanism, and the other end ered vehicle of this invention is a highly efficient and 40 to said frame via a biasing means, positioned to bias versatile machine. Its efficiency results from a light said drive mechanism through a return stroke, said weight, low friction design, conservation of kinetic flexible drive means traversing said overrunning energy, and excellent aerodynamics. The toggle style clutch, said overrunning clutch operably attached design of the drive mechanism yields excellent impe to said jackshaft to effect rotation of said jackshaft dance, matching of the arms and legs, high mechanical 45 in the forward direction, said jackshaft also con advantage, and an ergonomically correct motion. It is taining thereon a sprocket, said drive wheel with simple, yet extracts power from virtually every major said variable driving means driveably connected to muscle group of the body. It is economical to manufac said sprocket by an endless chain. ture and uses standard bicycle components. It is conve 2. The vehicle of claim I further including a roller nient to mount, and it has comfortable, easy handling 50 journaled at said lower end of said levering means characteristics. wherein said flexible drive means is deflected from a In addition, the basic drive mechanism can be supple straight course by said roller as said drive mechanism mented with a bicycle style crank arm with no addi approaches the end of said power stroke, thereby decel tional weight penalty other than the crank arms and erating said drive mechanism, and forcing higher rota pedals themselves. 55 tional energy into said drive train to assist said power Although the description above contains many spe stroke. cifics, these should not be construed as limiting the 3. The vehicle of claim 1 further including a crank scope of the invention, but instead as merely providing arm and pedal affixed at each end of said jackshaft and exemplifications of some of the presently preferred oppositely disposed, thereby enabling the pedaling of embodiments thereof. For example, the main drive 60 said vehicle as a standard bicycle. mechanism could be a separate unit from the frame. It 4. The vehicle of claim 1 whereby said frame approxi could take many forms and configurations. It could mates the form generally associated with standard two even take the form of a stationary exercise machine for wheeled recumbent bicycles. its excellent aerobic benefits. The frame could be made 5. The vehicle of claim 1, wherein said steering means to fold, and stair-climber type lever arms could be used 65 is a steering assembly, including: in place of the optional pedal-crank on jack shaft 53. a. cable sleeve stops Frame designs, steering assembly, and footrest assembly b. a drum on which the flexible steering cables are configurations are too numerous to attempt to list. wound and affixed. 5,280,936 9 10 c. a handlebar, and connected to form an upper side of the parallelograms, d. a short steering column, journaled in said steering thereby supporting said steering means in a more opera assembly on which said handlebar and said drum ble orientation in relation to a rider, throughout said are mounted. power stroke. 6. The vehicle of claim 1 wherein said linear motion 5 11. The vehicle of claim 1 wherein said elongated means is a footrest assembly, guidedly supported by flexible drive means is a chain. rollers between two square cross-sectional guide mem 12. The vehicle of claim 1 wherein said biasing means bers in a parallel, side-by-side configuration. is a spring. 7. The vehicle of claim 6 wherein said parallel guide 13. The vehicle of claim wherein said variable drive members contain therein front and rear stops to restrict O forward and rearward motion of said footrest assembly. means is a standard bicycle derailer. 8. The vehicle of claim 1 wherein said levering means 14. The vehicle of claim I wherein said steerable front consist of two lever arms pivoted from said frame, sub wheel utilizes a standard assembly for stantially alike, and parallelly disposed between which steering movement about a predetermined steering axis, are positioned said linear motion means and said steer 15 15. The vehicle of claim I wherein said handlebar is a ing means. standard bicycle handlebar utilizing standard compon 9. The vehicle of claim 8 wherein said steering means entry contained thereon. is rigidly mounted to said lever arms. 16. The vehicle of claim 1 wherein said seat is adjust 10. The vehicle of claim 8 further including two simi able along said longitudinal axis of said frame. lar linkage members pivoted from opposite sides of said 20 17. The vehicle of claim 16 wherein said seat is in frame in conjunction with said lever arms, forming two conjunction with a backrest, said backrest being sepa corresponding, modified, articulated parallelograms, rately adjustable from said seat. parallelly disposed with said steering means pivotally k k

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