Patent Application
20140124612
This disclosure relates to a multi-mode vehicle that can be used in two or more of land, water and ground effect flight.
Reference will now be made to certain embodiments and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure and the claims are thereby intended, such alterations, further modifications and further applications of the principles described herein being contemplated as would normally occur to one skilled in the art to which this disclosure relates. In several figures, where there are the same or similar elements, those elements are designated with the same or similar reference numerals.
Note that the terminal end of any numeric lead lines in the drawings, when associated with any structure, process or landmark described below is intended to representatively identify and associate the described feature. The terminal end of lead lines are not intended, nor should be inferred, to delimit or define per se boundaries of the referenced structure, process or landmark, unless specifically stated as such or facially clear from the drawings and the context of the description of the figure.
Unless specifically stated as such or facially clear from the figure(s) and the context in which term(s) is/are used, all words should be given their common commercial and/or scientific meaning consistent with the context of the below disclosure.
Referring to
Frame 102 generally includes the structural components that make-up vehicle 100, including any roll bar structures. Steering wheel 108 is linked to front wheels 104 to allow an operator to control the direction at front wheels 104 are pointing. This can be achieved by any means done in the art including, but limited to, rack and pinion system, a re-circulating ball mechanism, a worm and sector system or a capstan and bow string mechanism to name a few non-limiting examples.
Engine 112 is linked to drive rear wheels 106 through any transmission (not illustrated) known in the art including, but not limited to, belts and gears. The transmission can be a fixed ratio transmission or can be a variable transmission with multiple gear ratios. Engine 112 is controlled by a throttle (not illustrated). The throttle can take the form as a conventional foot pedal or a lever throttle or any other form of throttle may be used as desired.
Engine 114 is coupled to fan 116. In the illustrated embodiment fan 116 is coupled directly to the output of engine 114; however, a transmission system (not illustrated) could be optionally included. Any type of transmission known in the art may optionally be used including, but not limited to, a fixed ratio transmission or a variable transmission with multiple transmission ratios. Engine 114 is controlled with a second throttle (not illustrated). The second throttle may also be in the form of a foot pedal or a hand lever or any other form of throttle desired.
Fan cage 118 surrounds the operating envelope of fan 116. Fan cage 118 may optionally be augmented with mesh or netting structures to limit access to fan 116 from outside of fan cage 118.
Accessory mount supports 120 are attached to the bottom portion of front frame 102 and may be used as described below to attach accessories to vehicle 100 including, but not limited to, wings or pontoons.
Vehicle 100 is configured as a dune buggy and may be operated using either engine 112 and/or engine 114 to provide propulsion. Operating both engines 112 and 114 at full throttle provide higher velocity than operating either engine 112 or engine 114 at full throttle alone.
Referring now to
Wings 140 may also optionally include skid-arms 146 positioned under the leading edge of wings 140 near the outer tip of wings 140. Skid-arms 146 are flexible rods constructed and arranged to absorb and deflect impact of the wing tip against the ground and to push the wing upward. Use of skid-arms 146 may help prevent cart wheeling in the event a wing tip strikes the ground.
Tail assembly 150 includes tail supports 152, horizontal stabilizer 154, vertical stabilizer 156 and rudder 158. Tail supports 152 couple horizontal stabilizer 154 to frame 102 and/or fan case 118. Rudder 158 pivots on vertical stabilizer 156 and its relative pivot position is controlled by the operator (not illustrated). Any desired means to control rudder 158 may be used including, but not limited to, rudder pedals, lever, linkage by cable, a mechanical linkage and/or a motor driven fly-by-wire system with a motor pivoted rudder 158.
Wings 140 are designed for use with a particular configuration of vehicle 100 to allow vehicle 100 to fly in ground effect. Ground effect refers to the phenomenon that occurs when a wing is flying at or below an altitude that is approximately equivalent to the chord length of the wing (the shape of the airfoil also affects the maximum altitude of ground effect). In ground effect, the ground interrupts wing tip vortices and down wash behind the wing. This results in lower induced drag which increases the Lift to Drag (L/D) ratio of the wing. The influence of ground effect on induced drag decreases with altitude, so available thrust may also affect the maximum altitude a particular vehicle can travel in ground effect.
Wings 140 may include a cross section with an airfoil design optimized for operation in ground effect. As shown in
Flying kit 130 is designed to allow vehicle 100 to fly through ground effect, but at the same time being unable to lift vehicle 100 into free flight (flight out of ground effect). These design considerations also extend to the configuration of fan 116 and engine 114. That is to say that maximum thrust generated by fan 116 and/or the maximum lift generated by wings 140 are insufficient for vehicle 100 to enter free flight under normal operating conditions.
Referring now to
Canard assembly 160 includes canard supports 162 and horizontal stabilizer 164. Canard supports 162 attach horizontal stabilizer 164 to frame 102.
Rudder assembly 170 includes rudder 172 and mounting brackets 174 and 176. Mounting bracket 174 is attached to frame 102 and mounting bracket 176 is attached to fan cage 118. Together they support rudder 172 and allow rudder to pivot. Pivoting of rudder 172 is controlled by any mean known in the art including, but not limited to, a gear and pulley system, a mechanical linkage or a motor actuated system. The control interface for rudder 172 may also be any means known in the art including, but not limited to, rudder foot pedals or a hand lever. Alternatively, rudder 172 may optionally be controlled by steering wheel 108. Rudder assembly 172 may be permanently attached to vehicle 100 or may be configured to be removable.
In the embodiments illustrated in
While not illustrated, it is possible to optionally incorporate ailerons and/or elevators may optionally be incorporated into wings 140 and/or horizontal stabilizers 154 or 164 provide pitch and/or attitude control.
Referring to
In the illustrated embodiment, the combined lift capacity of wings 140 is approximately 2400 pounds (10.7 kN) of lift. While the design weight of vehicle 100 with wings 140 and either tail assembly 150 or rudder assembly 170 with canard assembly 160 attached is 650 pounds (295 kg). The design lift capacity of wings 140 far exceeds the lift capacity required to enter ground effect; however, designing excess lift capacity in wings 140 may allow use of comparably reduced thrust from fan 116 (and comparatively reduced airspeed while flying in ground effect). With 500 pounds (227 kg) of passengers and cargo capacity, the lift capacity of wings 140 is at least twice the maximum loaded weight of vehicle 100.
Engines 112 and 114 and fan 116 are configured with a specific wing 140 configuration so that fan 116 operating at maximum thrust provides insufficient velocity for vehicle 100 to enter ground effect flight (when operating on a substantially level surface). That is, in order to enter ground effect flight on a level surface, both engine 112 and engine 114 need to be operated together. Similarly, engine 112 operating alone on level ground provides insufficient velocity for vehicle 100 to enter ground effect flight. Engine 114, fan 116 and wings 140 are constructed and arranged to provide insufficient lift for vehicle 100 to exit ground effect flight and enter into free flight; however, once vehicle 100 reaches sufficient velocity to enter ground effect flight, fan 116 and engine 114 provides sufficient thrust for vehicle 100 to maintain flight in ground effect.
Vehicle 100 may operate as a ground vehicle using either engine 112 or engine 114 independently as power sources, or vehicle 100 may be operated with both engine 112 and engine 114 providing thrust. In the illustrated embodiment, engine 112 operating at maximum throttle propels vehicle 100 on level ground at approximately 35 MPH (56 km/hr). Similarly, engine 114 and fan 116 operating at maximum throttle alone propel vehicle 100 at approximately 32 MPH (51 km/hr) on level ground. Operating engine 112 and engine 114 together, both at maximum throttle, propel vehicle 100 at approximately 53 MPH (85 km/hr) on level ground. With wings 140 and either tail assembly 150 or canard assembly 160 and rudder assembly 170 attached with wings 140, vehicle 100 enters ground effect flight at approximately 40 MPH (64 km/hr). The maximum airspeed in ground effect flight with engine 114 with maximum throttle and fan 116 at maximum thrust is approximately 50 MPH (80 km/hr).
Referring to
In the case of an energetic material propellant, the propellant may include one or more reactive substance. If more than one reactive substance is used, for example, a fuel and an oxidizer, the substances may be transferred to jets 196 separately or mixed, depending upon the nature of the reactive substances used.
Tail assembly 250 includes tail support 252, horizontal stabilizer 254 and rudder 256. Tail supports 252 couple horizontal stabilizer 254 to frame 102 and/or fan case 118. Rudder 256 pivots vertically and its relative pivot position is controlled by the operator (not illustrated). Any desired means to control rudder 256 may be used including, but not limited to, rudder pedals, lever, linkage by cable, a mechanical linkage and/or a motor driven fly-by-wire system with a motor driven rudder 256.
When flying vehicle 100 with flying kit 134, altitude is controlled by varying the output of engine 198 with a throttle (not illustrated). Forward motion is generated by fan 116 and engine 114 and direction of flight is controlled by rudder 256 combined with thrust from fan 116. Tip jet rotors do not place torque on the airframe, so no counter-rotation system such as a tail rotor is required.
This disclosure serves to illustrate and describe the claimed invention to aid in the interpretation of the claims and to enable a person skilled in the art to make and use the claimed invention. However, this disclosure is not restrictive in character because not every embodiment covered by the claims is necessarily illustrated and described. The claimed invention is not intended nor should it be limited to the disclosed embodiments, but is to be accorded the widest scope consistent with the principles and features disclosed herein. All changes and modifications that come within the scope of the claims are desired to be protected, not just those embodiments explicitly described.
