Abstract:
This present invention provides an unconventional and proprietary flying “ground effect vehicle” or model. This vehicle features thrust propellers that generate airflow. The airflow is directed to the bottom of vehicle causing it to rise completely off the ground surface and as the airflow increases it is directed rearward so as to achieve and sustain forward “ground effect” flight. This type of flight effect occurs near the ground surface as the vehicle flies on a cushion of air that is generated between the ground surface and underside of the vehicle body with or without auxiliary horizontal stabilizers.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Ser. No. 61/305,268 filed on Feb. 17, 2010. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to remote control models, and more particularly to remote controlled ground effect model. 
         [0004]    2. Related Technology 
         [0005]    Conventional hovercrafts or air cushion vehicles are known as “vehicles which are able to lift up, hover just above the ground surface and move forward.” In order to hover or glide over the ground, these vehicles must reduce the drag from friction caused by contact with the ground surface as much as possible. Those types of vehicles, which are generally referred to as “hovercrafts,” generate airflow by propeller or fan and direct airflow evenly out from a gap between the bottom of the vehicle or skirt underneath vehicle and surface of the ground or water. However, this application still puts a portion of vehicle or skirt underneath into contact with surface of the ground or water. As a result, hovercrafts are easily caught or stuck on the ground when they encounter any surface protrusions, however small they may be. Also, hovercrafts can become easily stuck when they encounter any hollow or porous surfaces such as ditches, lawns or grasses. Those rougher terrains result in excess amount of air leakage from under the vehicle (or skirt) so overall friction drag is increased which results in slowing the vehicle down or stopping it altogether. 
       SUMMARY 
       [0006]    According to an implementation of the invention, the ground effect model includes a body having a front, a back, sides, a top and a bottom, at least one air duct having an inlet at the front of the body and an outlet positioned at the bottom of the body, at least one propeller positioned in the at least one air duct at the inlet to selectively increase air flow through the air duct from the inlet to the outlet, and at least one motor connected to the at least one propeller. 
         [0007]    According to another implementation, the ground effect model is configured to fly over a ground surface and includes a body having a front, a back, sides, a top and a bottom, a first air duct having an air inlet at the front of the body and an air outlet positioned at the bottom of the body, a second air duct adjacent said first air duct and being separated there from by a wall, said second air duct having an air inlet at the front of the body and an air outlet positioned at the bottom of the body, a first propeller positioned in the first air duct; a second propeller positioned in the second air duct, a first motor connected to the first propeller; a second motor connected to the second propeller, a first skirt positioned on the bottom of the body along an outer side of the air outlet of the first air duct opposite the wall, a second skirt position on the bottom of the body along an outer side of the air outlet of the second air duct opposite the wall, radio control electronics and a battery power source positioned on the body and connected to the first and second motors to allow independent wireless operation of the first and second motors. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    In the drawings wherein like reference numerals denote similar components throughout the views: 
           [0009]      FIG. 1  is top left side perspective view of the ground effect model according to an embodiment of the invention; 
           [0010]      FIG. 2  is bottom right perspective view of the ground effect model according to an embodiment of the invention; 
           [0011]      FIG. 3  is a sectional view of the ground effect model showing the air flow there through according to one operable state of the same; 
           [0012]      FIG. 4  is a sectional view of the ground effect model showing the air flow there through according to a second operable state of the same; and 
           [0013]      FIG. 5  is front view of the ground effect model according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The term “ground effect” flying vehicle or model, as referred to herein, is a vehicle or model capable of flying over the ground surface, yet utilizes the ground surface to maintain the desired ground flying effect. 
         [0015]    In operation, the vehicle first rises and achieves “ground effect” and secondly builds thrust to move forward by subsequent airflow in the rearward direction. The vectoring of the airflow to the bottom of the vehicle at start up (for lifting) and then vectoring immediately to the rear (for propulsion) is handled by proprietary hinged/pivoting flaps placed behind the propellers that operate passively as pressurized air or thrust flow over them. When a different rotational speed is selected for either left or right propeller, it creates a difference in thrust between left and right propellers thereby allowing the vehicle turn left or right freely. The vehicle is preferably designed to be as lightweight as possible to enhance performance and achieve “ground effect” flight more readily. 
         [0016]    In accordance with one exemplary implementation, the ground effect is achieved by a model having two propellers at left and right sides as described below, however, those of skill in the art will appreciate that the same effect can be also achieved by a vehicle with a single centrally located propeller which turns left or right by rudder. Additionally, a vehicle with more than two propellers can achieve the same effect. 
         [0017]    In accordance with one implementation of the invention, two thrust propellers can be installed diagonally in relation to the longitudinal center line of the vehicle so that propeller-generated airflow can be directed diagonally downward. The airflow can be channeled to the ground efficiently by the shape and configuration of vehicle body, so that the desired “ground effect” can be generated by increasing the air pressure between the vehicle body and the ground surface. 
         [0018]    As shown in  FIGS. 1 and 2 , the vehicle or model  10  consists of a body  12 , motors  24 , gears  26 , propellers  22 , RX PCB (receiver or printed circuit board)  28 , battery  30  and skirts  16 . The body  10  is preferably designed for efficient airflow to the ground and subsequent airflow in the rearward direction. The body  12  has a rear wing assembly which can consist of two vertical fins and a horizontal wing. The body  12  may also include auxiliary horizontal stabilizers  18  at each side. Left and right motors  24   a  and  24   b , control the rotational speed of the respective propellers  22   a  and  22   b , for thrust. The motors  24   a  and  24   b , and the thrust they generate via propellers  22   a  and  22   b , respectively, can be individually controlled by radio control (RC) or infrared rays (IR) using stepped or infinitely stepped proportional control. Furthermore, the rotational speed of the motors  24   a  and  24   b  can be reduced by gears  26   a  and  26   b , respectively, to make the propellers  22   a  and  22   b , turn more efficiently. In a preferred implementation, the configuration of left and right propellers  22   a  and  22   b , respectively, should be symmetric, and preferably counter rotate with respect to each other in order to cancel or eliminate an adverse “torque steer” condition. 
         [0019]    When a different rotational speed is selected for either the left or right propeller  22   a  or  22   b , respectively, the vehicle can be turned either to the left or to the right. Those of skill in the art will appreciate that differences in the rotational speeds of the left and right propeller will change the rotation radius of the model. For example, the larger the difference of the rotational speed between left and right propellers, the shorter the turning radius of the model will be, and vice versa. That is, the smaller the difference of the rotational speed between left and right propellers, the greater the turning radius of the model will be. Left and right air ducts,  21   a  and  21   b  (See  FIG. 2 ) in the body  12  are preferably completely separated from each other by a wall  40 , so air pressure in either duct is maintained, at their different respective levels, even in the event that either motor is stalled. 
         [0020]    As shown in  FIG. 3 , according to one embodiment pivoting flaps  32  are located just behind each of the propellers  22  inside the respective air duct  21  of the body. The pivoting flaps  32  are passively held down by gravity or by a spring biasing of the same when the propellers are not generating sufficient thrust. Rotation of the two propellers  22   a  and  22   b  at the frontal area of the body pulls air into the body ducts  21   a  and  21   b . As shown in  FIG. 3 , upon start up of the propeller rotation, inhaled air is steered by the downwardly directed pivoting flaps  32  and thereby directed toward the bottom (represented by lines A 1 , A 2 ). This airflow pushes against the ground surface G to force the frontal area of the body  12  to rise up as air pressure builds under the vehicle. 
         [0021]    As shown in  FIG. 4 , and in accordance with the increasing flow of air resulting from increased speed of the propellers  22 , the pivoting flaps  32  are pushed up by air pressure, such that the angle of the flaps becomes almost to parallel with respect to airflow A 1 , A 2 , and A 3  through the ducts  21 . In this position, airflow can be diverted to rear of the model and thereby turned into strong thrust force. The incremental velocity gain of the vehicle, will enable constant flying near the ground surface to be achieved. This ground effect flying can be further enhanced and/or stabilized when the rear wing assembly  14  and/or auxiliary horizontal stabilizers  18  are added to the body  12 . 
         [0022]    According to an alternative embodiment, the pivoting flaps  32  are removed completely from the model. With sufficient air pressure in the respective air ducts  21   a ,  21   b  as generated by propellers  22   a ,  22   b , the model can still operate as described above. The pivoting flaps  32  assist with the initial lift and flight in ground effect, but are not required for operation of the model. 
         [0023]    As shown in  FIGS. 1-5 , skirts  16  can be added to the underside of the body  12  such that they are positioned adjacent the output of the respective air ducts  21 . Skirts  16  are preferably made of flexible material and assist to prevent air leakage from both sides of the body initially as the vehicle rises at start up. As a result, the skirts  16  effectively operate to increase air pressure near the ground by containing the air enough to force the body to rise up. The skirts  16  also maintain air pressurization under the vehicle during “ground effect” flight. As shown in  FIG. 5 , the air effect resulting from the positioning and inward configuration of the skirts  16  is such that the model can fly over the ground G without physically touching the same. 
         [0024]    It is important to note that skirts  16  enhance flight over the ground surface by maintaining positive pressure area under the vehicle. However, in alternative implementations, skirts  16  are removed completely from the model. When there is sufficient air pressure in the respective air ducts  21   a ,  21   b  as generated by propellers  22   a ,  22   b , the model can still operate as described above without skirts  16 . 
         [0025]    While there have been shown, described and pointed out fundamental novel features of the present principles, it will be understood that various omissions, substitutions and changes in the form and details of the methods described and devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the same. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the present principles. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or implementation of the present principles may be incorporated in any other disclosed, described or suggested form or implementation as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.