Abstract:
An improved personal propulsion device that generally imparts thrust directly to the user. The device allows hands free control of thrust magnitude and direction so both hands can grasp and control bicycle handlebars and brakes, watercraft paddles, ski poles or other apparatuses. The device is adjustable vertically, on the users&#39; back, higher to allow sitting in a canoe or wheelchair and lower for standing on skates, skis, kick scooters etc. A user on a bicycle may prefer to lean forward for comfort and aerodynamics, a device adjustment compensates and delivers level thrust. A user on a snowboard or skateboard stands oblique to the direction of travel, a device adjustment allows in line thrust. Both users&#39; hands and arms are free to balance, protect others by pushing off or break a fall. The present invention can be provided as separate modules that allow interchangeability and use with a direct drive mechanism.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. patent application Ser. No. 11/477,238 filed Jun. 28, 2006, which issued as U.S. Pat. No. 7,331,833 on Feb. 19, 2008. 
     
    
     FEDERALLY SPONSORED RESEARCH 
       [0002]    Not Applicable. 
       SEQUENCE LISTING OR PROGRAM 
       [0003]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0004]    A. Field of the Invention 
         [0005]    This invention generally relates to personal propulsion devices that are worn on the back of a user or attachable to a moveable object, such as a bicycle, canoe, skateboard or other human-powered vehicle, ridden by the user to propel the user and the object. More specifically, this invention relates to such devices that provide for hands-free operation and control of the device and are configured to accept adjustments for versatility. Even more specifically, this invention relates to various improvements to the configuration of such devices that improve the usefulness and functionality of the device. 
         [0006]    B. Prior Art 
         [0007]    User-worn propelling devices to propel a person riding on or in a moveable object, such as a bicycle, skateboard, canoe, pair of skates and the like, are well known in the prior art. For instance, the propelling device of Morrill, U.S. Pat. No. 2,456,440, discloses a thrust device that is supported by one arm only. Unfortunately, the user is imbalanced by the offset weight and the center of thrust is in line with the one supporting arm of the user and, therefore, misaligned or offset from the center of resistance of the user&#39;s skates, as shown in  FIG. 3  of that patent. Torque about the user&#39;s vertical axis makes straight line travel and maneuverability difficult. Support of the device by one arm will rapidly become fatiguing to that arm and long duration travel will be uncomfortable or intolerable. The support bar along the side of the user, the gas tank and the throttle appendage in front of the user become a hazard in the event of a fall. The engine is located behind the propeller, thereby increasing the distance from the support and, therefore, increasing the cantilevered weight to the user&#39;s arm. Riding a modern bicycle with only one hand is dangerous as two brake handles are provided for safety in traffic. Sitting in and operating a wheelchair requires both hands for steering. The engine would interfere with sitting in the wheelchair. In a canoe or kayak, the engine would interfere with both hands and arms being required for the paddles. An engine speed of 18,000 to 20,000 rpm is dangerous as propellers can and do shatter, which may cause serious injuries to the user and bystanders. Six pounds of thrust is low and insufficient for overcoming inclines and soft snow with heavier users, and slow in watercraft against even a light wind. 
         [0008]    The propulsion support unit of U.S. Pat. No. 4,189,019 to Zech, discloses a complex system of levers, springs, turntable and bars on both sides of the users&#39; body. Both hands and arms are required for controls. The unit described with a 25-30 lb. motor, plus frame and support unit, would weigh approximately 40 lbs with the propeller and protection shroud. The frame top terminates in rigid tube ends which during a fall may on contact with the back or sides of the head and neck cause injury to the user. The control bars at the sides of the user present a further injury hazard in the event of a fall. The unit would be impossible to operate on a bicycle, and the position on the user&#39;s body would interfere with a canoe, kayak and wheelchair. On snow skis the requirement of both hands and both arms renders the user unable to grip and maneuver the pair of ski poles essential for balance, turning and accelerating over rough terrain. The many parts, heavy weight, high cost of manufacturing, hazardous in a fall, and both hands and arms occupied, make this invention less attractive as an alternative form of transportation. 
         [0009]    Zech further discloses a propeller shroud, as shown in  FIG. 7 . A sufficient body of research has proven the thrust is reduced substantially by shrouding, compared with an open propeller, without including an “inlet lip” of 15% diameter of the shroud (see Modern Propeller and Duct Design by Martin Hollman, 1993, pg 101—incorporated herein by reference). The current invention includes a bumper/flotation device that cooperates with airflow at the inlet end of the containment ring. 
         [0010]    The propulsion means set forth in U.S. Pat. No. 5,222,569 to Martel, discloses a device that imparts thrust “solely to the rear of the pelvic area.” The propulsion device is supported by a pendulum shoulder harness on the user and must be controlled by both hands on a pair of grips and pivoting handles along both sides of the user. These side handles are an injury hazard in a fall. The device is hanging free on the pendulum harness except for the users hands on the two handle grips, so in the event of a fall when the users hands release the handles to break the fall, the unit can swing around the neck or impact the users head and neck causing injury. The foot starting cable may become entangled around the user causing further injury. The device is located below the axis centered on the pelvic region and the user may not sit in a canoe, kayak, wheelchair or bicycle. Further more the users hands would be unavailable to grasp the required maneuvering implements such as paddles, brakes, handle bars, wheels of the wheelchair etc. If the user released the handles to grasp implements the unit would swing out of control causing an impact hazard. The propulsion device does nothing to improve open propeller inefficiencies (see Modern Propeller and Duct Design by Hollman, 1993, pg. 95 and 97-incorporated herein by reference). 
         [0011]    The current invention will overcome the above referenced hand and arm requirements. It will allow hands free operation and control of a simple light weight, efficient, economical, device that is adjustable up and down the user&#39;s back. The current invention eliminates the need for any side bar for control. This will allow co-operative use with any of the well known transportation or recreational human powered vehicles (HPVs) such as bicycles, kick scooters, wheelchairs, canoes, kayaks, small sail craft, skateboards, all ice and roller skates, snow skis, and etc. In addition, the current invention anticipates use proximate to crowds of people and, therefore, has many safety and convenience improvements. 
         [0012]    The light aircraft with inflatable parachute wing propelled by a ducted propeller of U.S. Pat. No. 5,620,153 to Ginsberg, teaches that the efficiency of an aircraft propeller is reduced at low speeds and can be improved by the addition of a duct, comprising support vanes to counter act the torque of the engine, and a propeller or fan centered and mounted rotationally within. The addition of the duct improves safety, reduces noise and improves thrust to power ration. Further study teaches that a ducted fan or shrouded propeller comprises an inlet lip attached and tangent to the duct with a special fan, turbine, or propeller of greater surface area than standard open aircraft propellers of the same diameter. It is known in the art that a very close tolerance between the propeller and the interior surface of the duct, 0.015 inch maximum up to an 18 inch diameter propeller is required. This close tolerance requires stiffened duct and vane arrangement and the cost of the composites and manufacturing of them, to stiffen the unit and retain the light weight features required in aircraft is prohibitive for a personal propulsion device. The rpm is also increased in a ducted fan and results in an unacceptable blade failure risk proximate to crowd and children on bicycle paths, sidewalks, and boardwalks for ground transportation. 
         [0013]    The current invention overcomes the dangers of the ducted fan and the prohibitive cost of the rigidity required and the lack of availability of ducted fan parts in the required sizes. The inlet lip is of a complex increasing radius design which also increases design and manufacturing costs (see Modern Propeller and Duct Design by Hollman, 1993, pg 101 and 102—incorporated herein by reference). 
         [0014]    The current invention improves the efficiency of the open propeller and improves the personal propulsion device safety using commonly available materials of very low cost and weight. The manufacturing processes required are simple and inexpensive. The propellers required are commonly available for large model aircraft in wood, plastic, fiber reinforced nylon, and other materials. The diameters and pitches are diverse and can be adapted for use in the current invention for any rpm, size user, or horsepower required in a two, three or multiple blade configuration. 
         [0015]    The recoil rope type manual starters that are standard in the industry have been improved to be operable from the user position. Tezuka et. al, U.S. Pat. No. 6,776,133, discloses a starter extension that is pulled along side the operator in the standard working position. None of the prior art machines adjust slidably up high on the users back and down low on the users back. This wide variation in propulsion device positions on the user, would dispose the starter handle in the region of the arm pit at its high adjustment. This position removes the strength and leverage advantage of the operators arm, against the load, due to the inconvenient position. The various positions on the users back facilitated by the current invention, would place the fixed end of the flexible tube and its fixing bracket, as shown in  FIG. 3 , in the path of the swinging arm or elbow of a canoe paddler or snow skier. The rigorous anticipated and intended uses of this current invention require free motion and unobstructed use of arms and elbows through their full range of motion, without chance of impact or contact with any part of the propulsion device. My current invention will over come the limitations and injury hazards of the prior art recoil starters. 
         [0016]    The prior art of personal propulsion means attached directly to the user has resulted in heavy, slow and generally inefficient devices. One or both of the hands and arms are continuously required for control of these devices. There are handles and appendages that create a safety and/or injury hazard to the user in the event of a fall. The devices lack sufficient adjustments in position on user, and thrust angle to provide wide versatility in cooperation with the many HPVs available today. As a result, presently there are no personal propulsion devices that are widely available on the market, therefore, the public has benefitted little from the prior art devices. 
         [0017]    As freeway, street, and parking lot crowding increase, the demand and cost of fossil fuels are at a record high world wide. Pollution from auto emissions is an increasing concern of the public and the global warming awareness is on the increase. The dependency of the United States on foreign oil and the consumption of world wide petroleum reserves will create new record high prices. Emerging countries&#39; fuel demand in conjunction with the aforementioned pressures, point to ever increasing prices and ever tightening supplies. 
         [0018]    A need exists for a compact, extremely low fuel consumption, user friendly, hands free operation, light weight, low emissions, unlimited range (with occasional refueling at any gas station) alternative transportation device. This need for alternative transportation is recognized widely as bicycle paths and designated bicycle lanes on streets and roads are being built at great cost and prompted aggressively. This is occurring in large cities and small towns alike, as the negative impact of too many automobiles is pervasive. The popularity of HPVs is at an all time high. The range of HPVs has always been limited by the endurance of the user and thereby eliminating much of the public from benefitting from such devices. 
         [0019]    The massive competition in the lawn and garden equipment market has resulted in rapid and major improvements to the motors. The resulting improvements directly benefit the present invention. The major improvements are reliability, manufacturer&#39;s product up to 2000 hrs of trouble free use. Emissions reductions; the public and community awareness of small engine pollution (especially two-strokes where oil is pre-mixed with gas) and in co-operation with state air resources agencies, have ever tightened standards of compliance among small engine manufacturers. User friendly features are now major selling points such as lighter weight and high power. Currently a 2.2 hp totally self contained motor weighs only nine pounds. Other features include a fuel primer bulb for first pull and easy starting, all position running, quieter mufflers, regular gas required with greater fuel economy and less vibration to the user. 
         [0020]    The current invention benefits from the motor configuration of the increasingly popular string trimmer. There are many manufacturers to select from. There are many power options and option packages to select from. A size and weight range of the present invention can be offered to the public to accommodate various sizes of users. The operator of the string trimmer benefits from the vibration isolation bushing between the engine and drive shaft housing and the current invention will benefit also. 
         [0021]    For the rest of this document the term string trimmer motor is implied to comprise the standard, widely available string trimmer motor which is totally self contained. It includes a centrifugal clutch so at an idle condition the load is at rest. It includes a leak proof all position fuel tank. It includes a recoil rope starter. It includes a vibration isolation bushing between the motor and the drive shaft housing tube. It includes a muffler and or catalytic converter and or spark arrester as local regulations require. It includes a carburetor having a fuel primer squeeze bulb, a convenient choke, a throttle, and an air filter. It may be of either the two stroke, more noisy and requiring premixed oil in the gas, but is lighter, or the four stroke, quieter, less exhaust emissions, uses regular gas but is heavier per horse power. These motors have smooth exterior cowlings and are air cooled. 
         [0022]    C. Objects and Advantages 
         [0023]    Accordingly, a number of objects and advantages of my invention are readily apparent from the above and summary and detailed description set forth below. For instance, the user of the present invention enjoys hands free control of the thrust magnitude imparted generally to the users back from no thrust to full thrust and any magnitude between these limits. In addition, the user enjoys the freedom of arms and hands free movement while operating the personal propulsion device without any control bars or protrusions extruding from the frame along the users sides, thereby improving safety in the event of a fall. The present invention can be adjusted high on the users back so the user can sit comfortably in a canoe, kayak, wheelchair or other HPVs and use both hands to freely paddle or maneuver, or break each with hands and arms unencumbered. In addition, my invention is light weight balanced and comfortable and can be used for hours without fatigue or discomfort. 
         [0024]    My invention includes an impact absorbing bumper around the circumference of the propeller to cushion the shock of impact imparted to the user and device in case of a fall. The bumper is light weight and acts as a floatation feature to give the device positive buoyancy incase user falls into the water during water craft use. 
         [0025]    My invention is adjustable to the middle of the user back to allow comfortable bicycle riding with both hands free to shift gears, operate both brakes and maintain both hands on the handle bars. An adjustment allows the user to lean forward into the racing position for comfort and improved aerodynamics and the device delivers horizontal thrust. 
         [0026]    My invention is adjustable rotatably about the vertical axis of the user to allow user to stand oblique to the direction of travel as on a skateboard or snowboard and deliver thrust inline with the direction of travel. The users&#39; hands and arms are free for balance and safety to grab objects or break a fall. 
         [0027]    My invention can be configured to push the user along at 25 miles per hour or greater on a standard road bicycle while achieving 150 miles to the gallon of regular gasoline without pedaling. It is believed that the device performance and efficiency will improve with continuing research and development. 
         [0028]    My invention allows the user to start the device from the users&#39; position so user stops the motor without remorse. This saves fuel at long traffic lights and promotes good will while coasting by crowds silently on boardwalks or street fairs etc. and when the noise even at idle would be offensive. 
         [0029]    My invention allows the user of a wheelchair increased range and freedom with the assistance of thrust while hands free control facilitates both hands on the wheels for steering and braking. 
         [0030]    My invention allows the user to purchase and operate the unit for transportation at an overall cost far less than other transportation means and yet enjoy unlimited range of travel. The user benefits from economical and effortless locomotion. 
         [0031]    The above and other aspects, objects and advantages of the present invention are explained in greater detail by reference to the attached figures and the description of the preferred embodiment which follows. As set forth herein, the present invention resides in the novel features of form, construction, mode of operation and combination of the above presently described and understood by the claims. 
       SUMMARY OF THE INVENTION 
       [0032]    The current invention generally is worn on the users back to impart thrust to the user to assist traveling on any bicycle, skates, skies, canoe, kayak, wheelchair or other HPVs. The device is adjustable slidable higher and lower on the users back to accommodate the aforementioned vehicles/apparatuses. The personal propulsion device allows hand free control of thrust magnitude so the user can grasp and operate any maneuverability or safety controls of above mentioned apparatuses, continuously, while simultaneously controlling said propulsion device. Adjustments of the thrust direction of the propulsion device allow the user to stand oblique to the direction of travel as on a snowboard or skateboard and deliver thrust inline with the direction of travel. The user can lean forward on a bicycle on a racing position to improve aerodynamics and comfort and the device can be adjusted to deliver horizontal thrust. Thus the reader can see that the user can travel economically and effortlessly on any HPVs or apparatus&#39; for reducing locomotive effort. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    In the drawings which illustrate the preferred embodiments and the best modes presently contemplated for carrying out the present invention: 
           [0034]      FIG. 1  is a side view of a Personal Propulsion Device configured according to a preferred embodiment of the present invention; 
           [0035]      FIG. 2  is a side view of a Personal Propulsion Device of  FIG. 1  shown on a user; 
           [0036]      FIG. 3  is an isolated a side view of the throttle control glove shown on the hand of a user; 
           [0037]      FIG. 4  is a side view of the Personal Propulsion Device shown on a user riding a bicycle in a n upright position; 
           [0038]      FIG. 5  is a side view of the Personal Propulsion Device shown on a user riding a bicycle in a crouch or racing position; 
           [0039]      FIG. 6  is a side view of the Personal Propulsion Device shown on a user in a canoe; 
           [0040]      FIG. 7  is a side view of the Personal Propulsion Device shown on a user riding a skateboard; 
           [0041]      FIG. 8  is a side view of a user with an airfoil shaping safety bag; 
           [0042]      FIG. 9  is a top view of a human torso with an airfoil shaping safety bag; 
           [0043]      FIG. 10  is a side view of the frame of the Personal Propulsion Device of  FIG. 1 ; 
           [0044]      FIG. 11  is a perspective view of the rear end of the Personal Propulsion Device; 
           [0045]      FIG. 12  is a cross-sectional side view of an alternative embodiment of the shrouded propeller assembly of the present invention shown with an airfoil utilized therewith; 
           [0046]      FIG. 13  is another alternative embodiment of the personal propulsion device of the present invention showing a cross-sectional side view of the propulsion means module and a side view of a propulsion means module utilized therewith to provide modular capability, shown in the detached position; 
           [0047]      FIG. 14  is a side view of an alternative embodiment of the control glove, shown on the hand of a user, utilized with the personal propulsion device of the present invention; 
           [0048]      FIG. 15  is a cross-sectional side view of an alternative embodiment of the shrouded propeller assembly of the present invention shown with a plurality of air horns; 
           [0049]      FIG. 16  is a side view of an alternative configuration of the personal propulsion device of the present invention shown mounted to a bicycle with a mounting mechanism; 
           [0050]      FIG. 17  is a side view of an alternative configuration of the personal propulsion device of the present invention shown mounted to a canoe with a mounting mechanism; 
           [0051]      FIG. 18  is a side view of an alternative configuration of the present invention shown mounted to a bicycle and engaged with a tire in a direct drive position; and 
           [0052]      FIG. 19  is a side view of an alternative configuration of the present invention shown mounted to a canoe and configured to turn a propeller to propel the canoe. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0053]    As shown in  FIG. 1 , in the preferred embodiment of the personal propulsion device  11  of the present invention the motor  29  contains a vibration isolated motor mount clamp  33  and is secured to the propeller shaft housing tube  30 . The pivot block  31  slides onto the propeller drive shaft housing tube  30  and is clamped securely by tightening pivot block bolt  32 . The pivot block  31  is attached to a light weight aluminum frame  21  with the pivot block bolt  32 . As the pivot block bolt  32  is tightened it secures other parts, shown in detail in  FIG. 11 , simultaneously. A comfort pad  22  is secured to frame  21  and padded adjustable shoulder straps  17  and  18  are attached to the top of the frame  21  and secured to bottom of frame  21  with clamps  20  and  20   a . The adjustable waist belt  19  is also attached to clamps  20  and  20   a . The throttle control glove  23 , which is shown in detail in  FIG. 3 , is connected to the motor  29  using a standard throttle cable  24  and ignition switch in general use today as small engine controls. 
         [0054]    The flexible over the shoulder recoil starter extension  34  is comprised of a flexible spring like housing  14  with a friction reducing plastic tube liner  13 . The recoil starter rope  12  is extended or replaced with a new rope  12  of sufficient length to accommodate the extension  34 . The rope  12  passes through tube  13  and is attached to pull handle  16 . The extension assembly  34  is secured to the frame  21  with clamp system  15 . This flexible and extended started improvement allows the starter  34  to conform to the padded shoulder strap  18  when the starter extension  34  is attached to the strap  18 . This allows easy access to the starter handle  21  when the device  11  is adjusted high on the user&#39;s back or low on user&#39;s back, as shown in  FIG. 2 . 
         [0055]    At the bottom or motor end of the starter extension assembly  34 , open rope  12  remains open and the housing flexible to allow the motor  29  to be pivoted at the pivot block  31  and still be pull started while misaligned relative to the frame  21 . Both ends are free and flexible to allow adjustments at both ends of the starter extension assembly  34 . 
         [0056]    The flexible over the shoulder recoil starter extension  34  is an improvement that other power equipment in use today will benefit from. For example, the backpack leaf blowers of the gasoline motor type have to be removed from the user to be started but with this improvement can be started from the user position. This feature improves convenience and allows stopping the motor without hesitation or remorse which conserves fuel and reduces unnecessary emission and pollution. 
         [0057]    In  FIG. 2 , the Personal Propulsion device  11  is in the middle to lower back position and viewed from the right side of user  112  to show the throttle control glove  23  on a right handed user. The throttle cable and run/stop switch wires are bundled together and attached to the user at the throttle control glove  23 , the elbow adjustable cable strap  25  and at the right shoulder strap  18  before it enters the motor  29 . A metal screen, not shown, is attached to the rear of the propellers shroud inlet lip  123  securely. These safety screens, not shown, if removed, will open a micro switch in series with the run/stop switch and immediately disables the motor  29  so it can&#39;t be started with the safety screens removed. 
         [0058]    The shoulder straps  17  and  18  are similar to the backpacks and leaf blower available currently but with greater length of adjustment to allow the user to shorten them by buckle adjustment to raise the personal propulsion device  11  high on the back for canoe, wheelchair use or etc. The waist belt  19  is designed to attain the alignment of the unit  11  with the direction of travel and can be adjusted to fit securely to various sized users. The waist belt  19  also secures the personal propulsion device  11  in position relative to the user&#39;s body in case of accidental fall. 
         [0059]    The over the shoulder recoil starter extension  34  and recoil starter pull handle  16  are positioned for ease of starting with either hand. When operating the personal propulsion device  11  in near proximity to other people, stopping the motor and coasting silently by and easily restarting on the go is desirable. 
         [0060]    The user  112  stands or sits in or on any wheeled mode of transport or in the water in any water craft or on ice skates, snow skies or other HPVs. The user starts the personal propulsion device  11  by pulling the starter handle  16 , then flexes or curls the index finger of the throttle/control glove  23  to increase propeller speed and forward thrust until desired speed is achieved. The index finger  27  can then be relaxed slightly to reduce thrust to maintain desired speed and cruise for fuel efficiency. 
         [0061]    The right fender  26 , shown in  FIG. 2 , is attached to the frame  21  with simple clamps to help smooth the airflow around the user and draw air into the propeller  122  more smoothly. The corresponding left fender is not shown, but acts and is attached in the same manner as the right fender  26  to smooth air flow and improve the look of the unit  11  as well as provide space to advertise, affix logos, and attach night lights or reflectors for improved visibility and to display manufacturer contact information. The fenders  26  also smooth the sides of the device  11  where the user&#39;s arms and elbows are most likely to contact the device  11  during vigorous paddling etc. 
         [0062]    The shroud  124  around the propeller  122 , the inlet lip  123 , and shroud support struts  25  comprise the shrouded propeller assembly  120 . The assembly  120  is lightweight, strong, and aerodynamically efficient in horsepower to thrust ratio, and relatively economical to build. 
         [0063]    The high cost of ducted fans, turbines and the high rpm required, creates hazards in fan or turbine failure and resultant explosion of parts. This makes operating these devices in close proximity to user&#39;s body and around others undesirable. An aluminum containment ring  28  is attached around the plastic shroud  124  in line with the propeller  122  tip line of travel reinforcing the shroud  124  against penetration of propeller parts in the event of propeller failure. Common rivets or screws with aircraft type locknuts should be used here to avoid parts loosening and contacting the propeller  122  in motion and becoming projectiles. 
         [0064]    As best shown in  FIG. 3 , the user  112  slides on the throttle control glove  23  until the adjustable wrist anchor strap  127  is around the small of the user&#39;s wrist  128 . The user  112  adjusts the wrist anchor strap  127  firmly to limit motion of throttle cable housing anchor plate  121 . Placing the finger end cap  125  onto the end of the index finger  27  of the user  112  enables the curling or bending of the index finger  27  to tension and draw the throttle cable  24  through the knuckle guide bushings  113 ,  114  and  115  to advance a typical throttle plate of any typical motor carburetor. This finger flexing controls the motor, speed, torque, and propeller thrust imparted to the user. Flexing more advances the throttle farther and increases the thrust. With throttle control glove  23  on the user&#39;s hand the run/stop switch  119  is switched to the on or run position. The motor  29  can be started in the backpack position or on the floor or table top to first warm it up, usually requiring activation of a carburetor choke briefly and only during the initial start of the use as a warm motor require no choke for starting. During the rest of the warm motor use the motor  29  can be started, stopped, and restarted from the backpack user position with the over the shoulder recoil starter extension  34 . The throttle cable guide bushings  113 ,  114 , and  115  are made of low co-efficient of friction material, such as a plastic tubing which allows some flexing across the users knuckles as the index finger  27  is flexed. 
         [0065]    The throttle cable guide bushings  113 ,  114 , and  115  may be attached to the throttle control glove  23  by an epoxy adhesive  116 . The throttle cable  24  tension can be adjusted by changing the position of the throttle cable housing anchor plate  121  on the wrist anchor strap  127  with a hook and loop material attached to each of said parts to accomplish a course adjustment. To accomplish a finer throttle cable  24  tension adjustment the throttle cable housing stop tube  118  is turned through threads in the throttle cable anchor plate  121  after loosening lock nut  111  and retightening the lock nut after adjustment is satisfactory. The course adjustment described above also helps accommodate the various sized hands of users and the throttle control glove  23  will be offered in various sizes. The glove  23  is detachable at the motor wire plugs, not shown, and the cable  24  is easily detached at the throttle plate  121 . This detachability allows interchangeability for color coordination or to allow users of different sizes to use the same propulsion unit. Many gloves  23  may be retained for the winter, summer, reflective, night riding etc. 
         [0066]    The throttle cable  24  is crimped to a malleable tube  126  such as brass and swedged onto the throttle cable  24  and conformed to finger end cap  125  and maybe attached to finger end cap  125  with adhesives or brazing the tube  126  to a metal finger end cap  125  made of metal such as a sewing thimble. The finger end cap  125  may have inserts of various sizes to accommodate various users. The throttle control glove  23  may be improved to include the carburetor choke control and other functions. The throttle control glove  23  may be right or left handed and may utilized only one finger to hot weather use. The throttle control glove  23  may be of breathable material for user comfort and a stretchable material to accommodate different sized user hands. 
         [0067]    The throttle control glove  23  may employ only an electronic wireless signal transmitter with receiver servos on the motor  29  to control as many functions as desired. These wireless remote controls have been in use for many years in hobby model cars and aircraft and are currently small, lightweight, reliable and inexpensive. The throttle control glove  23  may be detachable, to allow interchanging for different users and different seasons. The glove  23  can be detached and taken with the user  112  to disable the personal propulsion device  11  to discourage theft, similar to an ignition key for an auto. As these controls continue to improve, the personal propulsion device  11  may be controlled with eye lid motion, mouth motion or other controlled inputs. With preferred embodiment of my invention the user can enjoy the use of any vehicle with full grasp of both hands and thereby be safe while operation any transport device. 
         [0068]    In  FIG. 4 , the user  112  is shown on bicycle  30  in the common upright sitting position for bicycle riding and has adjusted the personal propulsion device  11  to the middle of the back position. The user  112  may, at times, dismount from the seat to the standing position, straddling the top bar of the bicycle with feet positioned on the ground. In the standing position the propulsion device  11  will still be clear of the seat and rear tire. 
         [0069]    In  FIG. 5 , the user  112  is on bicycle  130  and the pivot block  31  is adjusted to nearly 45 degrees from the original position to apply direct thrust in the direction of travel details. The user  112  benefits from the crouched position by reducing his frontal area and therefore wind resistance. The personal propulsion device  11  benefits from less air disturbance entering the propeller  122 . The thrust remains horizontal. 
         [0070]    In  FIG. 6 , the user  112  is shown in a canoe  131  and must first adjust the propulsion device  11  to the high back position as the surrounding gun whales are at his waist level and would interfere if the device  11  were fitted any lower. The bumper  129  acts as a flotation device, in the event the user enters the water displacing sufficient water to be over all buoyant. 
         [0071]    The user  112  benefits from the low back position on a skateboard  132 , shown in  FIG. 7 , as the center of thrust is closer to the wheel resistance of the skateboard  132 . The propulsion device  11  is rotated to an oblique angle to the user  112  but thrust is retained inline with the direction of travel by the waist belt  19 . The user  112  benefits from the throttle control glove  23  in that his hands are both free to use in any position to enhance balance and therefore safety. In the event of a fall, the user  112  can use both hands to break the fall instantly and without having first to release a grip on any sort of control bar. 
         [0072]      FIG. 8  shows the side view of user  112  with the front inflatable airbag  40  that protects the user  112  from frontal impact and reduces wind resistance. The personal propulsion device  11  benefits from the aero shaping of the front airbag  40  as the air flow is separated around the user  112  more smoothly and returns to the propulsion device  11  with less disturbance than without the aero shaping airbag  40 . The user  112  attaches the adjustable airbag retention straps  41  and  42  around his torso and tightens them firmly. The front airbag  40  may be used in co-operation with the rear air bag  43  by attaching the retention straps  44  and  45  as with the front airbag  40 . 
         [0073]    Using the front and rear airbags  40  and  43  simultaneously reduces the wind resistance so significantly and with very little weight increase that bicyclists, downhill skiers, hang gliders, etc. will establish economy endurance and speed records with the improved aerodynamics created with the airbags  40 / 43 . The airbags  40 / 43  may be attached outside of the user&#39;s clothing or may utilize specially designed garments to help retain airbags  40 / 43  in position and further smooth airbag to users&#39; body transition areas for smoother airflow. In any mode, the airbags should be of attractive high visibility colors for safety of user  112  and others. Many shapes of the airbags  40 / 43  will be created for various speeds and uses. In the present embodiment a stretchable material is reinforced to allow variable geometry aero shapes. As the airbags  40  and  43  are inflated with greater pressures they elongate, as shown in  FIG. 8 , for even less wind resistance. By complete deflating the airbags they can be stored away in a small space. 
         [0074]      FIG. 9  is a top view of a user  112  showing inflatable aero shaping front airbag  40  and co-operating rear airbag  43 . When front airbag  40  is used without a personal propulsion device  11  the greatly improved aerodynamic shape is completed with the rear airbag  43 . 
         [0075]      FIG. 10  is a side view of the lightweight aluminum frame  21  attached to the pivot block  31  with pivot bolt  32 . The frame  21  can be rotated forward to accommodate the user  112  lowering the profile of his or her body by crouching, and the pivot block  31  can be pivoted by loosening pivot bolt  32  and retightening the bolt in pre-set position to produce horizontal thrust in a new frame position, shown as dashed lines in  FIG. 10 . In another embodiment, a link rod  46  is threaded at the forward end and is attached to shroud support strut  25  and allowed to pivot by link rod bolt  47 . The link rod  46  is threaded through a female thread affixed to frame  21  and when the hand wheel  48  is rotated the pivot block  31  is pivoted while the personal propulsion device  11  is in user position. In the second embodiment, the pivot block bolt  32  is set with a castle nut and cotter pin to allow pivoting at will. Bolt  49  then clamps the propeller&#39;s thrust bearing and bolt  50  secures the propeller shaft housing tube  51 . 
         [0076]    This invention may include any pivot block actuator for speed, safety, and convenience of pivoting said pivot block including but not limited to hydraulic, pneumatic, electrical solenoid, mechanical or other wireless remote controls and should be considered part of this invention. 
         [0077]      FIG. 11  is a perspective drawing viewed from the right rear of the personal propulsion device  11  and details the pivot block  31  and its various functions. When the pivot block bolt  32  is tightened it compresses slot  52  to secure propeller shaft thrust bearing  53 . The propeller  122  is attached to propeller drive shaft  54  and the shaft  54  passes through the bearing  53  to the motor  29 , not shown. Propeller shroud  124  is attached to pivot block  31  by support struts  55  with bolts  56 . The propeller shroud  124  can be adjusted to round and set propeller  122  clearance by support spokes  57  by turning spoke nuts  58 . Pivot block  31  is attached to frame ends  59  by the pivot block bolt  32 . The spoke hub  60  is held in centered position by the propeller drive shaft housing tube  51  and the tube secured when bolt  32  is tightened, this clamping force also secures the motor  29 , not shown, as the motor clamps to the propeller shaft housing tube  51 . 
         [0078]    The pivot block  31  allows the interchangeability of various motor sizes, powers and types, i.e. 4 stroke or 2 stroke, smaller power and lighter or larger horsepower and heavier etc. in the same string trimmer configuration. The pivot block  31  also allows quick interchangeability of the propeller shaft thrust bearing  53  in the event of bearing failure or shaft diameter variations when the motor  29  is changed. The pivot block  31  also allows interchangeability of modular shroud/strut/bumper combinations. 
         [0079]    This modular interchangeable feature is highly desirable because people come in all sizes. For instance, a 110 lb female may enjoy a 16″ diameter propeller and 1 hp engine with 10 lbs of thrust and an overall weight of 10 lbs, whereas a 250 lb man may require an 18″ propeller and bumper combination and a 2.2 hp motor with 20 lbs of thrust and 17 lbs overall weight. The one pivot block  31  can be utilized to interchange frame sizes with the removal of only one pivot block bolt  32 . This pivot block/motor mount/bearing mount/frame mount/strut mount is a single light weight component that attaches all modular components together. This facilitates a wide variety of option combinations for user comfort, convenience and safety. 
         [0080]    Thus the reader will see that the personal propulsion device  11  of this invention is lightweight, quiet, economical, easy to operate, hands and arms are free and unencumbered during operation, and can be made to fit users from children to large adults. The device will save fuel and reduce emissions while providing transportation, fun and allowing users to benefit from a wide variety of HPVs. 
         [0081]    An additional improvement to the personal propulsion device  11  of the present invention is shown in  FIG. 12 . As shown therein, one or more airfoils  150  are disposed in a generally horizontal configuration within the shroud  124  of the shrouded propeller assembly  120 . In a preferred embodiment, airfoil  150  is attached to the interior surface  152  of shroud  124  utilizing a commonly available adhesive, which is selected based on its ability to secure airfoil  150  to the interior surface  152 , or various other appropriate attachment mechanisms. Preferably, the airfoil  150  is of a standard National Advisory Committee for Aeronautics (“NACA”) shape to yield a lift to drag ratio of 12:1 or better at an angle of attach of approximately four degrees. The area of airfoil  150  must vary with the weight and size of the shroud propeller assembly  120  and it should lift the weight to substantially neutralize it at maximum throttle so as to provide greatly increased comfort to the user with only eight ounces, on average, of thrust lost to drag out of the approximately fifteen pounds of average thrust produced by personal propulsion device  11 . The preferred embodiment, shown in  FIG. 12  with the airflow shown by the arrows A, utilizes a single airfoil  150  in a fixed position and the trailing edge thereof will be utilized to reinforce a rear wire guard, not shown. A plurality of airfoils  150  may be utilized to further reinforce the rear wire guard and they can be easily linked to vary the angle of attack to provide more lift. On long trips, where endurance is a major concern, the increased lift benefits of airfoil  150 , which are desirable, warrant the loss of thrust due to the additional drag. A shrouded propeller has never been supported directly on the back of the user and, as a result, the need for this improvement has only become apparent after many hours of using such a device and the moderate back and neck discomfort that resulted from such use. 
         [0082]    The further aft the airfoil  150  is positioned in the shrouded propeller assembly  120  the more lift leverage it applies at a given velocity, but the more static weight leverage it imparts to the user  112  when no thrust is being applied. This is of particular importance because when the airfoil  150  is positioned at the far aft position every gram of additional weight is effectively amplified to the user&#39;s back and shoulders. 
         [0083]    Another alternative embodiment of the present invention is set forth in  FIG. 13 . This embodiment utilizes a propulsion means module  154  and a power means module  172  to provide functional modularity to the personal propulsion device  11  of the present invention. As shown in  FIG. 13 , the power means module  172  removably attaches to the propulsion means module  154 , which comprises propeller  122  attached to propeller drive shaft  54  and held in place by the propeller nut  156  that is threadably received on the threaded portion  158  of drive shaft  54 . The thrust bearing block  160 , having an integral break-away fitting male part  162 , of thrust bearing  53  (not shown in  FIG. 13 ) is retained by tightening the bearing retaining/strut mount bolt  164 . Strut mount bolt  166  is shown in  FIG. 13 , but the shroud support struts  55  are omitted for clarity. Shroud  124  is integral with shroud inlet lips  123  and shroud interior wall  152 . Propeller drive shaft  54  is driven by a male square shaft drive fitting  168  that slips into a square female driver (not shown) when the propulsion means module  154  is connected to the pivot block  31  of the power means module  172 . The shroud adjustment spokes  57 , not shown in  FIG. 13 , attach to spoke hub  170 . 
         [0084]    The power means module  172  comprises pivot block  31 , which is attached to frame  21  with pivot block bolt  32 . Pivot block  31  clamps onto one end of motor mount tube  174  and the motor  29  clamps onto the other end of motor mount tube  174 . Separation tension adjustment bolt  176  is adjusted to set the removal force required to slip break away fitting male part  162  out of the female part in pivot block  31 . Although not shown in  FIG. 13 , the power means module  172  further comprises shoulder straps  17  and  18 , comfort pad  22 , starter means  16 , waist belt  19  and control glove  23 . 
         [0085]    The broad diversity of intended uses of the personal propulsion device  11  is beneficially achieved by the interchangeability feature of the propulsion means module  154  and power means module  172 . In addition, repairing, servicing and upgrading of the personal propulsion device  11  will generally only require the propulsion means module  154  to be shipped, which typically requires a round trip. 
         [0086]    When separation adjustment bolt  176  is loosened, the propulsion means module  154  will break away by the square male shaft drive fitting  168  slipping out of the female square driver (not shown) of pivot block  31 . This feature can also be important during use of personal propulsion device  11 . For instance, during skateboarding activities, such as skateboard exhibitions where giant aerobatics are performed, it is possible, if not somewhat expected, that user  112  will fall. A light tension setting of separation tension adjustment bolt  172  allows the modules to relatively easily separate, thereby imparting less impact to the user  112 , propulsion means module  154  and shrouded propeller assembly  120  during the break-away. 
         [0087]    As shown in  FIG. 13 , motor  29  is retained in its desired position with pivot block bolt  32  during interchanging of propulsion means module  154 . If the motor  29  requires removal or adjustment pivotally, the pivot block bolt  32  is loosened, allowing motor  20  to be removed by withdrawing motor mount tube  174  or allowing the angle of thrust relative to the user&#39;s body to be adjusted, and then pivot block bolt  32  is re-tightened. 
         [0088]    The propulsion means module  154  further comprises an optional magnet  178  imbedded in or attached to magnet plate  180 . A plurality of powerful rare earth magnets may be imbedded in or attached to magnet plate  180  and an electrical coil wound around an armature (not shown) or a plurality of coils may be mounted to the pivot block  31  in a position that when the propulsion means module  154  is connected to the power means module  172 , the proximity of the magnets  178  to the electrical coils creates electricity as the magnet plate  180  rotates with propeller  122 . This electrical configuration is accomplished with no belts, gears or secondary drive apparatuses and can charge an on board battery for continued LED illumination even when the propeller  122  is not turning. The magnet plate  180  diameter can be made as large as needed and more magnets  178  attached to provide more wattage, with the attendant power diversion from the propeller  122 . Nighttime safety lighting is so important that the power diversion will be accepted my most users. As an option, the personal propulsion device  11  can also include an electric start feature for motor  29 . 
         [0089]    An optional cam lobe  182  is attached to cam lobe plate  184  and driven by propeller shaft  54 . A small, lightweight diaphragm-type compressor, not shown, can be mounted to pivot block  31  such that when propeller  122  is turning air is compressed. The compressed air can be utilized to inflate tires, inflatable shroud inlet lips  123 , inflatable shrouds  124  and/or aero shaping bags and the like. A small lightweight pressure tank may be pressurized such that even when the propeller  122  is not turning air pressure is still available. Small diameter quick couplers may connect the tank to the compressor only when needed. 
         [0090]    An alternative embodiment of the control glove  23  utilized with the personal propulsion device  11  of the present invention is shown in  FIG. 14 . The improved control glove  23  facilitates setting cruise speed, engine idle speed and/or throttle response sensitivity. The improvement is particularly desirable for use when personal propulsion device  11  is utilized with HPVs that require or are benefitted by the use of a full, strong four finger and thumb grip, such as when holding a canoe paddle or a ski pole. During a full hand grip, the index finger is flexed around a canoe paddle or ski pole, as examples, which causes the throttle to remain at full power. The improved control glove  23  resolves this issue. 
         [0091]    The improved control clove  23  has an intermediate spring  190  that is threaded onto base spring  192  such that simply turning the base spring  192  applies tension or releases tension to the throttle actuating cable  24  by applying pressure to the throttle cable housing  194  through the base spring  192 , which is threaded onto the threaded portion  196  of a cable housing termination fitting  198 . The long, finely wound and very flexible spring  200  is threaded into intermediate spring  190 , which is cooperatively sized for a tight interference fit. The flexible spring  200  allows intermediate spring  190  to rotate freely several revolutions in either direction to increase tension and, therefore, sensitivity or to decrease tension/sensitivity. This “on the fly” adjustment feature allows the user  112  to increase the idle speed when the motor is cold or at high altitudes. The user  112  may also adjust the cruise speed by turning intermediate spring  190  to the desired power setting in conjunction with a given steady grip position of the hand. By rotating intermediate spring  190  in the relaxing direction, the user  112  can flex all four fingers in a full grasp with the thumb wrapped inward and not affect the throttle until the wrist  202  is flexed slightly, which increases tension on the throttle cable  24  and increases the throttle and thrust. The widely versatile control system described above is a significant improvement to the safety of user  112  by allowing him or her to utilize both hands with a full strong grip on the HPV or other apparatus and still remain in full control of the personal propulsion device  11 . 
         [0092]    In a preferred embodiment of control glove  23 , a sleeve  204  made out of a stretchable material is stitched onto control glove  23  at the seams  206  and to form a small tube  208 , shown at the top of sleeve  204 . Alternatively sleeve  204  can be attached to control glove  23  utilizing other mechanisms or be formed integral with control glove  23 . In the preferred embodiment, one end of flexible spring  200  is inserted into the fabric forming tube  208  at the top of sleeve  204  and sewn into place at one or more stitch points  210  to anchor one end of flexible spring  200  to the control glove  23  and yet allow unrestricted flexing of the index finger  27 . 
         [0093]    The three spring assembly, comprising base spring  192 , intermediate adjustment spring  190  and flexible spring  200 , protects the small, relatively fragile strands of the ultralight cable  24  utilized in the preferred embodiment of the present invention. This protection from physical damage to the cable  24  is further improved by the use of a tension type spring so the coils of the spring are substantially closed to keep out dirt silicates and other abrasives. Where the knuckle flexing of index finger  27  opens the coils of flexible spring  200  the widest, the use of the fabric tube  208  covers and protects the cable  24  from such abrasives. 
         [0094]    An adjustment to cable housing  198  can be set and locked with lock nut  212  to cable housing stop plate  214 . A course adjustment can be made quickly by ripping cable housing stop plate  214  from wristband strap  216 , disposed around the user&#39;s wrist  202 , by releasing the hook and loop fastener  218  and repositioning the stop plate  214  relative to the strap  216 . 
         [0095]    As will be readily understood by those skilled in the art, the present control glove  23  is versatile, safe and allows the opposed thumb to be used in conjunction with all four fingers in a full, strong and safe grip. The prior art control gloves do not allow this level of gripping and do not provide for the various adjustments thereto that are available in the present control glove  23 . In addition, the present control glove  23  allows a wider variety of user sizes and intended uses with the same control glove  23 . Further, other controls can be incorporated into control glove  23 , such as wrist flexing to the right to steer a HPV or other apparatus to the right and wrist flexing to the left to steer to the left. The adjustable sensitivity control glove  23  allows steering and setting center for straight travel with similar “on-the-fly” adjustments. 
         [0096]    The adjustable sensitivity control glove  23  described above can be utilized with a propulsion device, such as the personal propulsion device  11  of the present invention, or other propulsion devices. The control glove  23  can be utilized with the cable  24  connecting to the throttle or with a variety of wireless mechanisms. In general, the adjustable sensitivity control glove will make many activities safer and more comfortable. 
         [0097]    A cross-sectional view of an alternative embodiment of the shrouded propeller assembly  120  for use with the personal propulsion device  11  of the present invention is shown in  FIG. 15 . As shown, the shrouded propellor assembly  120  comprises a shroud  124  having a shroud interior wall  152 , air exit end  220 , propellor  122  and air inlet lip  123 . The shrouded propellor assembly  120  is more efficient than an open propellor assembly of the same size due to the inlet lip  123  smoothing the air flow, shown in arrows on  FIG. 15 , to conform it to the interior wall  152  of the shroud  124  and the close tolerance of the propellor  122  to the shroud interior wall  152 . This close tolerance limits propellor tip vortices and turbulence as air continuously spills from the high pressure side to the low pressure side of any propellor tip or wing tip. 
         [0098]    With the air flow generally parallel to the interior wall  152  the highest speed portion of the propellor  122 , the propellor tip, propels clean air flow with little loss due to turbulence of the tip. The great inrush of air necessary for propulsive efficiency can draw foreign objects into the shroud  124  and propellor  122 , which can cause damage to the device  11  or injury to user  112  or other persons as the propulsion unit is in close proximity to the user  112  and any bystanders. Another issue with regard to shroud  124  is that noise awareness has increased. In fact, noise is treated as an emission by some regulatory agencies. The addition of the shroud  124  has been documented to actually increase the noise level and it is believed that this is due to the interference of the propellor  122  and/or the shroud support struts  25 . Traditional wire mesh safety guards disturb the incoming air and reduce thrust and do little or nothing to reduce the noise level. As set forth below, the present invention improves the shrouded propellor assembly  120  in three ways. 
         [0099]    As shown in  FIG. 15 , the improved shrouded propellor assembly  120  further comprises multiple inlet air horns, such as first air horn  222 , second air horn  224  and third air horn  226 , to help conform the air to its most efficient flow pattern possible, as indicated by the air flow arrows shown in the figure. The air horns  222 ,  224  and  226  are preferably molded together with spacers or the like, not shown. 
         [0100]    As set forth above, the personal propulsion device  11  of the present invention is worn on the back of the user  112 . Unfortunately, this blocks the air flow that would otherwise inflow generally parallel to the shroud interior wall  152 . In the present embodiment, the air flows around the user  112  and the multiple air horns  222 ,  224  and  226  direct the air so that it is parallel to the axis of propellor  122  and the shroud inlet wall  152  and generally parallel to the inlet lip  123  of shroud  124 . The high speed air passing air horns  122 ,  124  and  126  exert aerodynamic forces as any curved wing in an air stream, namely there is higher pressure on the inside of the curve and lower pressure on the outside of the curve resulting in “forward lift” and adding to the thrust created by propellor  122 . As shown in  FIG. 15 , the air horns  122 ,  124  and  126  are shaped like a curved wing in that their leading edges  228  are generally rounded and the trailing edges  230  are generally pointed. This configuration further helps the air flow to become generally laminar and increases the “forward lift”. In one configuration, the air horns  222 ,  224  and  226  are made out of an acoustically deadening material or sound absorbing material to absorb noise and/or reflect noise away from the ears of the user  112 . An additional benefit of air horns  222 ,  224  and  226 , provided by them being generally in close proximity to each other, is that they prevent sizable foreign objects from entering the area of propellor  122  and no arm or hand could accidently enter this area during a fall or an impact. For smaller users  112 , having smaller hands, the air horns  222 ,  224  and  226  are closer together. As will be understood by those skilled in the art, the use of air horns  222 ,  224  and/or  226  with the shrouded propellor assembly  120  adds propulsion efficiency, reduces noise to the user  112  and improves safety for the user and any bystanders. Another potential benefit of the closely spaced air horns  222 ,  224  and/or  226  is that this could eliminate the requirement for a wire mesh guard, a feature that is believed to be important for use with a wireless remote control glove  23  due to the wire mesh being a well known source of RF interference. 
         [0101]    An alternative embodiment of the personal propulsion device  11  of the present invention is shown in  FIGS. 16 and 17  with a HPV. In  FIG. 16 , a typical bicycle  130  is fitted with a standardized mounting mechanism, shown as  232 , that is configured to cooperatively engage an adapter, fitting or like device, not shown, on the personal propulsion device  11  so that the device  11  can be securely mounted to bicycle  130 , via mounting mechanism  232 , as shown in the figure. This option allows the user to ride the bicycle  130  without the weight of the personal propulsion device  11  on their back. In  FIG. 17 , the canoe  131  is fitted with the mounting mechanism  232  and the personal propulsion device  11  is mounted thereto to provide power to the canoe without the user  112  having the personal propulsion device  11  on their back. Preferably, mounting mechanism  232  when used with canoe  131  will be configured to position the personal propulsion device  11  lower toward the waterline to maintain the center of gravity as low as possible. In addition to being more comfortable for the user  112 , this configuration is also likely to be safer in case of canoe  131  capsizing and allows the user  112  to more freely move about while paddling, fishing, trolling or other activities. In addition to bicycle  130  and canoe  131 , the mounting mechanism  232  can be utilized with other HPVs. Because some governmental agencies may consider bicycle  130 , canoe  131  or other HPV configured in this manner to be a motorized vehicle, the use of this embodiment may be restricted to “open” areas. 
         [0102]    It is strongly preferred that the embodiments of  FIGS. 16 and 17  be utilized in conjunction with the wireless remote control glove  23  because the motor  29  is disposed at a greater distance from the user  112  than when it is on the user&#39;s back. It is unsafe to attach a control glove  23  to any apparatus from which the user  112  may be separated from in a crash or fall, as the tensile strength of the average throttle cable  24  is between 100 and 200 lbs. The user  112  could be entangled in or be dragged by the cable  24 , which could jerk the user&#39;s arm or hand hard enough to possibly cause serious injury. Preferably, the only time a throttle cable  24  attached to the user&#39;s hand and the apparatus can be deemed safe is when the apparatus is secured to the user  112  and cannot be dislodged by accident. 
         [0103]      FIGS. 18 and 19  show an alternative configuration of the present invention in use with a bicycle  130  ( FIG. 18 ) and a canoe  131  ( FIG. 19 ). As shown in the figures, bicycle  130  or canoe  131  is fitted with a standardized mounting mechanism  232  that is configured to attach to power means module  172 , which operatively connects to a direct drive propulsion mechanism  234  that, in  FIG. 18 , engages a tire  236  of bicycle  130  to propel bicycle  130  over a surface such as a road or the like or, in  FIG. 19 , propels canoe  131  across the water. In a preferred embodiment, the mounting mechanism  232  attaches to frame  21  by an adapter, fitting or like device, not shown, on frame  21 , which is connected to pivot block  31 . Pivot block  31  is attached to motor  29 . In this embodiment, the propulsion means module  154 , described above in conjunction with  FIG. 13 , is removed from pivot block  31  so that the direct drive propulsion mechanism  234  may be attached thereto. In the embodiment of  FIG. 18 , direct drive propulsion mechanism  234  comprises a thrust bearing block  238  and direct drive cone  240 , which is rotatably supported by a thrust bearing, not shown, and driven by a square end drive shaft, also not shown. In the embodiment of  FIG. 19 , the direct drive propulsion mechanism  234  comprises a marine-type propeller  242  at the end of drive shaft housing tube  244  enclosing a flexible drive shaft with a sealed propeller bearing (both not shown). As with the embodiment of  FIG. 13 , the direct drive module  234  inserts into the pivot block  31  of the power means module  172  and the separation tension adjustment bolt  176 , not shown in  FIGS. 18 and 19 , is tightened firmly. 
         [0104]    In the embodiment of  FIG. 18 , the friction drive cone  240  rides in firm contact with the tire  236  of bicycle  130  when pivot block  31  is rotated to bring motor  29  nearly vertical so as to dispose direct drive cone  240  against the tire  236 . The direct drive cone  240  may be adjusted relative to the tire  236  by pivoting pivot block  31  and thereby adjusting the effective gear ratio. In the embodiment of  FIG. 19 , the pivot block  31  is rotated to place marine propeller  242  in the water at the desired depth. The embodiments of  FIGS. 18 and 19  improve the comfort of user  112  by positioning the weight of the propulsion device to the frame of bicycle  130  or the canoe  131  and reduces the noise by eliminating the propellor  122 . In the embodiment of  FIG. 19 , the user  112  has more freedom of movement to paddle, fish or engage in other activities. 
         [0105]    The embodiments of  FIGS. 18 and 19  are only recommended for use in conjunction with the wireless remote control glove  23  described above. As will be readily understood by those skilled in the art, the embodiments of  FIGS. 18 and 19  allow the personal propulsion device  11  to be transformed by interchangeability to a quiet, fuel efficient direct drive system that can be easily pivoted to disengage the device to allow the user  112  to peddle or paddle freely if desired or out of fuel. It is believed that the embodiment of  FIG. 18  can achieve fuel consumption levels of 150 mpg and a catalytic converter can be added to approach zero air pollution emissions. When not used to provide power to the HPV, such as bicycle  130  or canoe  131 , the direct drive module can be pivoted out of the way and the HPV operated as normal with relatively little added weight (i.e., approximately 12 lbs.). 
         [0106]    Many other variations are possible for the present invention. For example, a stretchable fabric can be affixed over the inlet end of the propeller shroud and stretched over the round bumper and attached at the back end of the propeller shroud to add color and smooth the airflow over the device. The pivot block  31  can be mounted rotatably about a vertical axis and both horizontal and vertical rotation of thrust may be controlled by D.C. step motors and remote control switches on the control glove  23 . The glove  23  may be detached and retained with the user  112  after dismounting and leaving the device  11 . This is a disabling feature of the propulsion unit  11  to discourage theft. Without possession of the glove  23  the thief could not start or operate the device  11 . 
         [0107]    While there are shown and described herein specific forms of the invention, it will be readily apparent to those skilled in the art that the invention is not so limited, but is susceptible to various modifications and rearrangements in design and materials without departing from the spirit and scope of the invention. In particular, it should be noted that the present invention is subject to various modification with regard to any dimensional relationships set forth herein and modifications in assembly, materials, size, shape and use. For instance, there are numerous components described herein that can be replaced with equivalent functioning components to accomplish the objectives of the present invention.