Human powered vehicle

A human powered vehicle of the pedal-driven type having three or more wheels, a frame and seat for supporting one or more riders in a generally supine position, and a streamlined shell enclosure with a transparent canopy which is openable for entry and egress of the rider. The preferred embodiment for a single rider has two steerable wheels located forward of the rider at approximately the widest part of the streamlined shell, and a single fixed drive wheel centrally positioned behind the rider. The drive wheel is equipped with a multi-sprocket gearing arrangement, and a large pedal-equipped sprocket wheel is mounted in a position slightly forward and above the common axis of the front wheels for ready engagement by the rider's feet. A single drive chain extends from the drive sprocket to the sprocket cluster and passes around idler rollers which direct the chain beneath the rider.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to human powered or pedal-type vehicles, such as 
bicycles or tricycles, and more particularly relates to such vehicles 
having a streamlined shell for reducing wind resistance and improving 
performance. 
2. Description of the Prior Art 
Conventional fixed-gear bicycles have been in existence since around the 
turn of the century. During that time the basic design has changed very 
little. The only significant improvements have been in the chain/gearing 
system. The most successful of these improvements has been the 
now-familiar derailleur gear-changing system. Other improvements include 
the coaster brake, the multi-ratio planetary hubs, and the elliptical 
front sprocket. All of these drive train improvements have added to the 
roadability and cruising capability of the bicycle, culminating in the now 
conventional multi-geared (typically ten-speed) bike which is an elegant 
design having a drive mechanism perfected to nearly 95% efficiency. 
Because the basic power source of a human powered vehicle is limited, the 
speed such a vehicle can obtain is a function of the total drag presented 
at different speeds. The higher the total drag characteristics of the 
man/machine combination, the more limited the speed. 
Total drag on any rolling vehicle is equal to rolling wheel drag plus aero 
drag. Despite its sophistication in mechanical design, the present 
conventional design and development have not addressed the problem of aero 
drag. At best, the conventional bicycle provides a layout of frame, seat 
and handle bars which calls for the rider to assume a rather severely 
humped-over position. While this reduces drag to a slight extent, it is 
also quite uncomfortable and is acceptable only to racers and the more 
serious cycling afficionados. 
With the current trend of increasing scarcity and cost of fuels for vehicle 
propulsion, it becomes appropriate to seriously consider the feasibility 
of human powered vehicles as commuting vehicles. However, despite the 
clear need for such use of human powered vehicles, the commuter field has 
scarcely been penetrated. While bicycles are more popular now than ever 
before, they are still used mainly for recreation and exercise. Only a few 
of the more serious bicycling enthusiasts use such vehicles for commuting 
to and from work, and then only for short distances of ten miles or less. 
There is a real need for a breakthrough which will render human powered 
vehicles more attractive and feasible as commuter vehicles. 
The conventional unstreamlined bicycle has a fairly large aerodynamic 
frontal area and a high drag coefficient. The drag due to wind resistance 
increases nonlinearly with speed and becomes a substantial limiting factor 
for the expenditure of less than extreme effort at speeds above 15 or 20 
mph. There have been a number of efforts at trying to reduce bicycle/rider 
wind resistance in order to reduce the effort required to develop better 
vehicle speeds. Some of the resulting arrangements involve adding a 
streamlined shell to a bicycle, which has the effect of reducing stability 
and making the vehicle actually dangerous in cross winds of any noticeable 
magnitude. Other developments have produced three-wheeled streamlined 
vehicles in which the rider pedals lying on his stomach with his head 
forward, a relatively uncomfortable and unsafe arrangement. A suitable 
combination of rider position, propulsion and wheel arrangement with 
improved streamlining is needed before a truly acceptable human powered 
commuter vehicle is realized. 
SUMMARY OF THE INVENTION 
The present invention is characterized in the accompanying Abstract, 
incorporated herein by reference. In brief, a basic arrangement in 
accordance with the present invention is a fully streamlined tricycle 
having the rider in a supine position. The vehicle includes a fixed rear 
drive wheel, two steerable front wheels, a set of foot cranks mounted on a 
drive sprocket for rotational engagement by the rider's feet, a 
multi-sprocket drive cluster affixed to the rear wheel and linked by a 
chain to the front sprocket, a mechanism such as a derailleur for shifting 
the chain to different sprockets in the cluster, freewheeling rollers 
which direct the chain beneath the rider, a braking mechanism, and a 
streamlined shell with an openable transparent canopy for providing entry 
and egress to the vehicle. The rider sits leaning back, facing forward 
with his feet extending forward. The rider steers and controls functions 
such as braking and gear shifting with his hands. 
The position of the rider with feet forward and head nearly erect is more 
comfortable than a stomach-down position and is much safer in a collision 
than a head-forward position. In addition, the rider can exert greater 
pedalling force than is possible in the position used with a conventional 
bicycle. This position also affords the rider excellent visibility to the 
front and sides. Mirrors can be placed on the inside of the transparent 
canopy to provide excellent visibility to the rear. 
The power train is relatively simple and uses available bicycle components, 
such as cranks, sprockets, shifters and chain. The three-wheeled 
arrangement provides considerably more stability than is possible with a 
bicycle, particularly with a bicycle which is equipped with a streamlined 
shell. In addition, the placement of the rider on the underslung frame at 
or below the wheel axles greatly lowers the center of gravity. 
The aerodynamic design of the streamlined shell dictates that the fairing 
is widest at a point approximately 30 to 60% of the total length back from 
the nose. The placement of the two front wheels at this point 
advantageously develops the optimum compromise of maximum stability with 
minimal drag. The forward part of the body can be characterized as bullet 
shaped with a drooped nose. The sides and top of the shell are gently 
rounded in continuous curvature at their respective junctures. Aft of the 
widest part of the body, the shell is smoothly tapered to a vertical 
blade-shaped edge at the rear. The location of the single rear wheel just 
forward of this rear edge also accords with the compromise of stability 
and streamlining. The result is a superior combination of vehicle 
structure--running gear, drive train, rider position, etc.--with a 
streamlined shell enclosure which develops improvements in vehicle 
stability, rider comfort and safety, pedalling effort, aerodynamic drag, 
and other features which are important to the realization of a 
satisfactory human-powered commuter vehicle. This improved combination 
also achieves the capability of higher top speeds, superior to those of 
vehicles designed by others in attempts to solve the common problem. 
Preferred embodiments in accordance with the present invention presently 
hold world speed records for vehicles of this type, having set records in 
excess of 55 mph for a single-rider vehicle, in excess of 60 mph for a 
two-rider vehicle, and an average speed of better than 50 mph for a 
distance of 41 miles in a two-rider vehicle. 
The sides and top of the shell constitute a symmetrical low-drag airfoil. 
The bottom of the shell enclosure includes a central flat section which is 
curved and faired to meet the side portions. The shell totally encloses 
the tricycle structure except for slots in the bottom through which the 
lower portions of the wheels extend. With a rider placed in such a 
vehicle, the machine/rider combination has a center of gravity so 
positioned that all three wheels have approximately equal loading, thus 
adding to stability and optimum tire wear. 
Standard state-of-the art low-drag airfoils are able to maintain laminar 
fluid flow up to the widest point of their shape. However, if there is any 
disturbance of the smooth shape of the vehicle's nose, this laminar flow 
will be lost, and an increase in drag will result. A preferred embodiment 
of the present invention has no wheels or other disturbing protrusions in 
the body until nearly the widest point, the place at which the flow is 
expected to transition naturally from laminar to turbulent flow. Thus, the 
low drag achieved by this design more closely approaches theoretical low 
limits. Moreover, the underflow body with curved, faired side edges allows 
more ground clearance than a straight-sided design of the prior art which 
extends virtually to the ground in an effort to reduce drag. The present 
body shape increases roadability without the drag increase associated with 
a straight-sided design having reasonable road clearance. 
In alternative arrangements of the present invention, the shell may be 
stretched aft of the single rider position with the essential duplication 
in front-to-back juxtaposition of the frame, seat and drive sprocket to 
accommodate a second rider. In this configuration, the riders are seated 
essentially back-to-back, and the first rider's drive sprocket is coupled 
via a first drive chain and a second sprocket mounted on the second 
rider's pedal shaft to a common drive sprocket also mounted on that shaft. 
The common drive sprocket in turn drives the variable speed gear cluster 
mounted on the rear wheel. The first chain traverses a figure 8 
configuration while the second chain is threaded through a direction 
reversing mechanism so that both riders can pedal in conventional fashion 
to drive the rear wheel in the forward direction. 
In another alternative arrangement, a pair of rear wheels, located side by 
side, is provided for added stability. These two rear wheels are closer 
together than the front wheels in accordance with the streamlined shape of 
the shell. Other drive arrangements may be utilized, such as hand-powered 
or linear drives, for example. A small internal combustion engine may be 
added, as in powered hang gliders, for higher performance without unduly 
increasing the weight.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As particularly shown in FIGS. 1 and 2 illustrating one preferred 
embodiment of the invention, a single rider vehicle 10 comprises a 
streamlined shell 12 having a removable, transparent canopy portion 15 
mounted on a body portion 16. The upper forward part of the body 16 is a 
transparent shell 14 which is adhered to the lower part of the body 16 and 
shaped in accordance with the aerodynamic design of the overall shell. The 
vehicle running gear comprises a pair of front wheels 18 and a single rear 
wheel 20. The vehicle drive train comprises a drive sprocket 22 bearing a 
pair of pedal cranks 24 to which pedals 26 are affixed and mounted forward 
of the front wheels on the cantilevered forward portion 28 of a unitary, 
longitudinal tubular frame member 30. The frame member 30 is underslung 
along its central portion 32 and is curved upwardly at a rear portion 34 
which supports a padded headrest 36. A foam-padded reclining seat 38, 
shown partially broken away in FIG. 2, is mounted on the frame 30 to 
support the rider in a supine position. The drive train further comprises 
a gear cluster 40 mounted on the hub of the rear wheel 20. The gear 
cluster 40 provides a six-speed transmission system of the derailleur 
type. Respective pairs of idler pulleys 42 and 44 serve to guide the drive 
chain 46 along the frame underneath the seat between the drive sprocket 22 
and the gear cluster 40. For rider protection, a roll bar in the form of 
an inverted U-shaped member 50 is attached to the frame by a cross member 
52 and mounted adjacent the headrest 36. The rear wheel is mounted by 
means of fork members 39 to points of attachment on the frame 30. 
Control of the vehicle is effected by means of a "joy stick" 54 which is 
held by the rider while driving. This joy stick incorporates steering, 
braking and gear shifting controls and has mounted thereon a toggle-type 
gear shift lever 56, a hand grip 58 and a hand brake lever 60. The brake 
lever 60 is coupled by conventional cable means 62 to conventional 
caliper-type rim brakes (not shown) which may be mounted on the rear 
wheel, the front wheels, or on all three wheels if considered necessary. 
Hub brakes may be provided, if desired. An instrument cluster 64 is also 
shown mounted near the joy stick 54 and may include a speedometer and 
other instruments as desired with, in these days of microprocessors, a 
route computer. The joy stick column 66 is mounted to the frame 30 to 
permit rotation about its axis, and steering is effected by rotating the 
joy stick 54 about the frame axis, thus pivoting the steering rods 68 
which extend from each front wheel 18 and are coupled by ball joints to a 
steering arm (not shown) attached at the base of the column 66. The front 
axle 70 is underslung to accommodate the rider position and its attachment 
to the frane 30, and extends upwardly at its outer extremities to the hubs 
of the front wheels 18. 
The outer ends of the rear cross member 52 and a downwardly depending 
support rod 72 provide a 3-point mounting arrangement to support the lower 
shell portion 16 from the frame 30. Resilient mounting pads 73 of soft 
rubber or the like material serve to absorb road vibration transmitted by 
the frame and isolate the shell therefrom. This serves to prevent 
vibration of the shell which would interfere with free air flow along the 
shell and is particularly effective at the forward support rod 72, which 
is ahead of the point where air flow transitions naturally from laminar to 
turbulent. This mounting is readily releasable by removable pins (not 
shown) so that the shell and the internal structure can be easily 
separated, when desired, as for effecting repairs to the wheels, tires, 
running gear, etc. The unbreakable plastic canopy 15 is set in place and 
may be latched by a pair of latches 74 at the sides near the rider 
position. One or more stiffeners or cross braces 76, 77 may be provided 
for the body 16 and to support the upper portion 14. The canopy 15 may be 
removed, for operation as a roadster if desired, and stowed inside the 
vehicle. The canopy position is aft of the point at which turbulence 
develops naturally from the aerodynamic shape, so the open cockpit 
develops less drag than would a similar opening located farther forward. 
FIGS. 3 and 4, schematic views of a side elevation and plan, respectively, 
of the vehicle 10, are presented to show further details of the vehicle 
drive arrangement. In these views, the chain 46 is shown extending about 
the drive sprocket 22 and passing rearwardly along the idler or guide 
pulleys 44, 42 to the derailleur shifting system 40 with its jockey 
pulleys 41 affixed to the rear tricycle wheel 20. As it passes from the 
drive sprocket 22 to the gear cluster 40, the chain 46 passes along one 
pair of idler wheels 42, 44--say the pair to the right of the vehicle 
10--which on its return traverse to the drive sprocket 23, it passes along 
the leftmost pair of idler wheels 42, 44. 
Referring now to FIGS. 5 and 6, in which the shape of the streamlined shell 
is detailed, it will be noted (also see FIG. 1) that the forward portion 
of the shell resembles a bullet shape with what may be characterized as a 
drooped nose. In other words, the forward portion of the shell departs 
from symmetry about a central longitudinal axis represented by the dash 
line 80. The locus of points constituting the centers of respective 
transverse sections such as 82 in the forward portion of the shell is 
represented by the dotted line 84, shown curving downwardly from the 
longitudinal axis line 80. Along a mid portion of the shell, the 
circumferential shape departs from symmetry about the central longitudinal 
axis 80 by virtue of a flat bottom portion 85 generally extending between 
the front wheels 18 and toward the rear wheel 20. Slots 86 and 88 are 
provided for the wheels 18, 20, respectively, the forward slots 86 having 
extended transverse openings at their front and rear to accommodate 
steering movement of the front wheels 18. As is most apparent in FIGS. 5 
and 6, the shell is faired gently inwardly as it progresses from the mid 
portion to the rear section, accommodating to the narrowness of the 
internal chassis at the rear wheel 20 and continuing the gentle 
streamlining to a vertical blade-like termination at the rearward edge 90. 
This not only accommodates to the streamlining of the shell about the rear 
wheel 20 but also provides an added element of stabilization at higher 
operating speeds. The shell is symmetrical about a vertical plane through 
the central longitudinal axis 80. 
The preferred streamlined shape of the shell represents an adaptation of a 
particular computer-developed symmetrical airfoil. The principal 
modifications involving the drooped nose and the flattened bottom portion 
are incorporated to accommodate the ground effects encountered by virtue 
of operation near the ground surface. Theoretical aspects of the design 
are developed by considering the shell as though it were reacting in an 
airstream to a mirror image of itself, with the ground being the plane of 
the mirror. The shell develops an "underflow" body which allows more 
ground clearance than a straight sided design of certain particular prior 
art vehicles. This not only increases roadability without the drag 
increase associated with a straight-sided design having large road 
clearance, but also improves the streamlining for air flow under the body. 
Good aerodynamic design calls for the fairing of the shell to be widest at 
a point approximately 30 to 60% of the total length back from the nose. It 
also calls for the body to be smoothly tapered to a line or point in the 
rear. The tricycle arrangement of the present vehicle having two front 
wheels positioned at or near the widest point of the body and one rear 
wheel in the center at the back produces a natural fit between the 
theoretically ideal body shape and the chassis. The vehicle has no wheels 
or other disturbing protrusions in the body forward of the widest point in 
the shell airfoil, thus avoiding any interference with the natural laminar 
fluid flow until near a point where the laminar flow of a smooth airfoil 
naturally transitions to turbulence. The advantageous combination of 
tricycle chassis and streamlined shell of the present invention is such an 
improvement over prior art vehicles of the type involved that the initial 
embodiment of the invention ran more than 10% faster than the previous 
year's record in its first competition. Furthermore a single seater 
version of the design set a new record for distance cruising of over 36 
miles pedalled in one hour. 
Variants of the preferred embodiment depicted in FIGS. 1-4 may include 
variations in the propulsion mechanism. One such alternative arrangement, 
shown schematically in FIG. 7, incorporates pedal members 102 adapted to 
slide along a support surface 104 and coupled via links 106 to pedal 
cranks 108 on a drive sprocket 110. The remainder of the drive arrangement 
and chassis is similar to that already described for the principal 
embodiment. Other forms of linear drives are also possible. 
Another alternative arrangement, shown schematically in FIG. 8, 
incorporates the drive arrangement of the principal embodiment of FIGS. 
1-4, but further includes an auxiliary drive mechanism utilizing hand 
cranking. Thus, FIG. 8 shows a main drive sprocket 120 coupled to the rear 
drive gear cluster 40 via a chain 46 carried along idler wheels 42, 44 as 
already described, together with a secondary drive sprocket 122 having 
pedal cranks 124 and hand grips 126. The secondary drive sprocket 122 is 
coupled to the main drive sprocket 120 via a secondary drive chain 128 and 
a coupling sprocket 130 affixed to the main drive sprocket 120. Although 
not shown in detail, the hand grips 126 will be understood to include 
mechanism for controlling the vehicle, for example, to effect the braking, 
shifting and steering of the vehicle. These control mechanisms are coupled 
to their associated actuating mechanisms via flexible cables (not shown). 
Other modifications may be incorporated to improve the safety and comfort 
of the rider, thus making the vehicle more acceptable as a general 
human-powered commuter vehicle. For example, FIG. 9 which is a side view 
of a vehicle 10, partially broken away to show the interior details, shows 
fairing members 140 and 142 extending downwardly from the lower portion of 
the body 12 and about the front wheels 18 and rear wheel 20, respectively, 
to further reduce the aerodynamic drag developed by the wheels. Inside the 
vehicle 10, enclosures 144 provide wheel wells or fenders, thus both 
protecting the driver from inadvertently contacting the wheels, and also 
serving to keep road dirt, water, etc. from being taken up into the rider 
compartment by the rotating wheels. Thus, vehicles in accordance with the 
present invention are rendered suitable for travelling in all kinds of 
weather, the occupant being protected against rain and the like to 
essentially the same extent as though he were riding in a conventional 
automobile. Air intakes 146 with internal vent controls may be 
incorporated to provide selectively variable ventilation to the rider, 
with inlet air being drawn out the tail via a narrow slot 148. Ventilating 
air may also be drawn in through an opening 149 (see FIG. 1) at the nose 
of the vehicle. This position is a stagnation point and thus does not 
interfere with the laminar air flow around the shell. 
A further alternative arrangement is illustrated by the bottom view of FIG. 
10 in which a pair of spaced-apart rear wheels 20A, 20B is substituted for 
the single rear wheel 20 of FIGS. 1-4. These are principally provided to 
achieve additional stability for the vehicle and may be moved slightly 
forward of the position of the wheel 20 in the single-rear-wheel version, 
partially extending on either side of the occupant position. 
FIG. 11 is a schematic view particularly showing details of the drive 
arrangement and rider positions in a tandem version of the vehicle of the 
present invention. In FIG. 11, a vehicle 150 is shown set up to 
accommodate two riders in back-to-back position. The vehicle has a pair of 
front wheels 152 and a single rear wheel 154. The portion for the forward 
rider, having a first seat 156, is essentially the same as the 
corresponding portion shown and described in connection with FIGS. 1-4. A 
second rider position is shown having seat 158 for positioning the second 
rider between the first rider and the rear wheel 154. A central 
longitudinal frame member 160 extends underneath the rider positions to 
support the respective chain sprockets and, by axle and spindle mounting 
members, the wheels 152, 154. These mounting members have been omitted 
from FIG. 11 for simplicity, but correspond to the wheel mounting members 
shown in FIG. 2. First drive sprockets 162 and 164 are mounted in hubs 166 
at the ends of the tubular frame member 160. Pedals 168 are mounted on 
shafts which rotate within the hubs 166. In the rearward section, a main 
drive sprocket 170 is affixed to the same shaft as the sprocket 164 and is 
positioned between the pedals 168, being located to the right side of the 
rear wheel 154, while the sprocket 164 is located to the left side of the 
wheel 154. 
The sprocket 164 is provided for the purpose of coupling the forward drive 
sprocket 162 to the main drive sprocket 170. A first drive chain 172 
extends between the first drive sprockets 162 and 164, and is threaded in 
figure-eight fashion about the two sprockets 162, 164. Between these 
sprockets, it is directed underneath the rider positions and along the 
frame 160 via respective pairs of side-by-side pulleys 174, 176 and 
through parallel chain tubes 178. With the chain 172 arranged in this 
fashion, both riders are able to pedal in conventional fashion; that is, 
the forward rider pedals to turn the sprocket 162 counterclockwise as 
shown in FIG. 11, while the rear rider pedals to drive the sprocket 164 in 
a clockwise direction. Thus the pedalling effort from both riders is 
effectively applied to turn the main drive sprocket 170 in a clockwise 
direction. A second drive chain 180 is threaded along the sprocket 170 
over only a partial sector at the lower edge thereof, being guided and 
held in position on the sprocket 170 by means of guide rollers 182, 183. 
The chain also extends over a conventional derailleur 184 at the rear 
wheel 154. Thus, rotation of the main drive sprocket 170 in a clockwise 
direction results in force being applied to drive the rear wheel 154 in a 
counterclockwise direction. A headrest 186 is positioned centrally to 
accommodate both riders. 
The shell 190 is essentially a stretched version of the shell shown in FIG. 
1, and has essentially the same nose and tail portions with an elongated 
mid-section. Thus the aerodynamic shape in accordance with the present 
invention is preserved, materially reducing the aerodynamic drag of the 
vehicle. Such an embodiment of the invention has attained speeds in excess 
of 60 mph. It is also feasible to provide the second rider position with 
an auxiliary hand cranking mechanism as shown in FIG. 8, coupled to an 
additional sprocket mounted alongside the sprocket 164 for additional 
driver input. All controls are mounted adjacent the forward rider 
position, with the possible exception of auxiliary braking controls for 
the rear rider. 
There have thus been disclosed herein various embodiments of a human 
powered vehicle which give promise of satisfying the need for a suitable 
commuter vehicle which can take the place of the automobile, motorcycle or 
other motor driven vehicle over reasonable commuting distances. Although 
pedal-driven and constructed mostly of various parts adapted from the 
bicycle industry, the vehicle provides safety, comfort, speed and 
effective range far exceeding the capabilities of the conventional 
bicycle. The vehicle has demonstrated its superiority over other attempts 
to develop human powered vehicles capable of supplanting the standard 
bicycle. When brought into mass production, vehicles of the present 
invention are expected to penetrate substantially the market for commuter 
vehicles. 
Although there have been described above specific arrangements of a 
human-powered vehicle in accordance with the invention for the purpose of 
illustrating the manner in which the invention may be used to advantage, 
it will be appreciated that the invention is not limited thereto. 
Additional features may be incorporated as, for example, small auxiliary 
power sources such as gas engines or electric motors for longer distance 
cruising, mechanisms, for regenerative braking and energy storage, and the 
like. Also a mechanism may be included for canting the rear wheel when 
crosswinds are encountered, thus developing some forward drive from a sail 
effect. Accordingly, any and all modifications, variations or equivalent 
arrangements which may occur to those skilled in the art should be 
considered to be within the scope of the invention as defined in the 
annexed claims.