Abstract:
A three wheeled wireless controlled toy stunt vehicle capable of both highly elastic impact and less elastic impact with obstacles struck while the vehicle is in motion is disclosed. Two wheels are separately driven, and have tires with interiors that are vented to atmosphere. The third wheel has a tire with an interior that is sealed and pressurized. The pressurized tire is capable of highly elastic impact when it strikes obstacles while the toy vehicle is in motion. The non-pressurized tires are characterized by a less elastic impact with obstacles. The third wheel has a diameter that is larger than a diameter of the drive wheels. All components of the vehicle are contained within the two planes tangent to the three wheels, such that the toy vehicle may be operated on either of its two major sides.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit of U.S. Provisional Patent Application No. 60/340,112, “Three Wheeled Wireless Controlled Toy Stunt Vehicle”, filed Oct. 26, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to wheeled toy vehicles, and, more particularly, to wireless controlled two-sided toy vehicles capable of performing stunt maneuvers. 
     Toy wheeled vehicles are well-known. Toy vehicles, like the full-sized vehicles they often replicate, typically have a top side with a vehicle body portion and a bottom side with wheels, and generally are capable of operation only when the top portion is oriented upwards. Toy vehicles often flip over during play activities, and the user must interrupt his or her play to upright the vehicle. It is thus advantageous for a toy vehicle to be capable of operation with either its “top” or “bottom” side in the upright position. The prior art does disclose vehicles capable of operating with either of the vehicle&#39;s two sides oriented upwards. Specifically, U.S. Pat. No. 5,667,420, incorporated by reference herein in its entirety, discloses a six wheeled wireless controlled toy stunt vehicle in which the six wheels are sized and positioned around the vehicle chassis in a way such that the vehicle chassis is fully surrounded by the wheels and is capable of operating on any adjoining two pairs of the wheels. U.S. Pat. Nos. 5,887,985, 5,919,075, and 6,095,890, incorporated by reference herein in their entireties, all disclose a four wheeled wireless controlled toy stunt vehicle in which the four wheels are positioned at the corners of the vehicle chassis and are of such a size that the outer perimeters of the wheels define a volume fully enclosing the remainder of the toy vehicle so that the vehicle can operate on either of two major sides. 
     Children at play with toy vehicles like those described in the above-identified patents are prone to crash such toy vehicles into obstacles. A toy vehicle that is capable of a wide variety of responses to such collisions should be more engaging to a user than a toy vehicle with less varied responses. A collision response may be characterized by the degree of elasticity of the collision: a highly elastic collision results in a pronounced rebound of the toy vehicle, a less elastic collision results in a less pronounced rebound. One factor affecting the elasticity of a collision of the toy vehicles described in the above-identified patents with an obstacle is the elastic characteristics of the toy vehicle tires. Pneumatic tires typically result in more highly elastic collisions, while non-pneumatic tires generally result in less elastic collisions. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is directed to a three wheeled wireless controlled toy stunt vehicle which comprises a chassis having a first major side and a second major side opposite the first major side; two independently controlled drive motors within the chassis; a battery power source connected to the chassis, the drive motors receiving power from the battery power source; two drive wheels located on opposite lateral sides of the chassis proximal one longitudinal end of the chassis, each drive wheel being operably coupled with a separate one of the two drive motors; a third wheel located at an opposite longitudinal end of the chassis generally centered with respect to a longitudinal central plane through the chassis and through the major sides of the chassis, the longitudinal central plane separating the two drive wheels from one another; and the two drive wheels and the third wheel being of a size with respect to a remainder of the vehicle such that outer perimeters of the three wheels define a volume fully enclosing the remainder of the vehicle. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. 
     In the drawings: 
     FIG. 1 is a perspective view of a three wheeled toy stunt vehicle of the present invention; 
     FIG. 2 is an isometric top plan view of the vehicle of FIG. 1; 
     FIG. 3 is a partial broken away isometric side elevation of the vehicle of FIGS. 1 and 2; 
     FIG. 4 is a isometric view from the right end of the vehicle of FIG. 3; and 
     FIG. 5 is a exploded view of the vehicle of FIGS. 1-4. 
     FIG. 6 is a block diagram of the electrical components of the vehicle of FIGS.  1 - 5 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment three wheeled toy stunt vehicle of the present invention is shown in the various figures and is indicated generally at  10 . The vehicle  10  includes a chassis  12 , with first and second major opposing sides  14  and  16 , two wheels  18 , each located on opposite lateral sides  15  and  17  of the chassis  12  at one longitudinal end  19  of the chassis  12 , and a larger third wheel  20  located at an opposite longitudinal end  21  of the chassis  12  along a central longitudinal plane  22 . The central longitudinal plane  22  extends through the chassis  12  and major sides  14  and  16 , and divides the vehicle  10  in half, separating the drive wheels  18  from one another. The chassis  12  includes a main body portion  24  housing motors  26   a  and  26   b  (FIG. 5; the motors  26   a  and  26   b  are herein identified both as individual motors  26   a  and  26   b  and are also identified generically simply as  26 ), a preferably rechargeable battery power source  28  (FIGS. 1,  4 ) and control electronics (the general location  30  of which is indicated in phantom in FIG.  5 ). Extending outwardly from the main body portion  24  along the sides of the third wheel  20  to approximately the center of the third wheel  20  and first and second support arms  32  and  34 , respectively. The arms  32 ,  34  support the third wheel  20  for free rotation on the chassis  12 . 
     Referring to FIG. 5, the vehicle  10  is shown in an exploded view. The chassis  12  includes two independently controlled preferably reversible, electric drive motors  26   a  and  26   b , each driving a separate one of the drive wheels  18  on opposite lateral sides  15 ,  17  of the chassis  12 . A reduction drive indicated generally at  36  operably couples one motor  26  and one drive wheel  18  and will be described with the understanding that a mirror image reduction drive  36  exists between the other motor  26  and the other drive wheel  18 . An axle  38  extends transversely completely through the chassis  12  and supports at each end for free rotation a drive member  40  of each reduction drive  36 . The drive member  40  includes a drive gear portion  42  and a splined shaft portion  44 , which is received in the hub  46  of the drive wheel  18 . A separate reduction gear axle  48  is provided in each drive train and supports a combination reduction gear  50 . A motor pinion  52  is mounted on drive shaft  54  of the motor  26 . The various gears of the reduction drive  36  are seen assembled in FIG.  3 . 
     The chassis  12  preferably is formed by a bottom housing  56 , a top panel  58 , a pair of mirror image gear box covers  60  and  62  and a battery box  64 . Within the chassis, heat sinks  66  and  68  surround the motors  26 . The location of a PCB board  70 , which includes the electrical components for a radio receiver  72  and antenna  74 , signal processor  76  and motor controller  77  (see FIG.  6 ), all of which are conventional, is indicated generally at  30 . As best seen in the exploded view, the hub  46  of each drive wheel  18  is keyed to slidingly receive and engage the splines on the shaft portions  44  of the drive members  40 . Arms  32 ,  34  extend outwardly from one end of the main body portion  24  or remainder of the chassis  12  on either side of the third wheel  20  to about the middle of the third wheel  20  to rotatably support that wheel. The third wheel  20  preferably includes a tire  78  and a pair of conical hubs  80  and  82  and is supported for free rotation between the arms  32  and  34  on axle  84 . A cover  86  is provided on arm  34  for decorative purposes. A pair of “shock absorbers”  88 , each formed of halves  88   a  and  88   b  (FIG.  5 ), are further provided on cover  86 , also for decorative reasons only. Arms  32  and  34  are generally rigid so that all cushioning from impact of the third wheel  20  with an obstacle comes from the third wheel  20 . 
     It should be noted that tires  90  of the drive wheels  18  are hollow and resilient and have an interior space open to atmosphere in order that they may resiliently collapse upon impact and absorb kinetic energy. On the other hand, the tire  78  of the larger third wheel  20  is hollow and sealed and includes a pin valve  92  operably coupled with its interior space enabling the user to adjust the pressure within that tire  78  to modify the performance of the vehicle  10 . 
     The three wheels  18 ,  20  are sized with respect to the chassis  12 , which is the remaining portion of the vehicle  10 , such that the outermost periphery of the three wheels  18 ,  20  define first and second tangent planes  100  and  102  which bound the remaining portion of the vehicle  10 . This permits the vehicle  10  to be operated on either of its two major sides  14  or  16 . It further enables the vehicle  10  to be driven back and forth in a way that enables the chassis  12  and third wheel  20  to rotate about the drive wheels  18  and the axle  38  from one side of the drive wheels  18  to an opposing side of the drive wheels  18  thereby exposing either of the major sides  14  or  16  of the vehicle  10 . It further permits the vehicle  10  to be driven on planar surfaces towards planar obstacles and rebound from those obstacles, always landing on its wheels, even when initially landing on a lateral side  15  or  17  of the vehicle  10 , for continued stunt performance. Furthermore, because of the different construction of the drive wheels  18  and third wheel  20  (uninflated and inflated, respectively), the vehicle  10  will perform differently from the prior art four and six wheeled vehicles in which the wheels of the vehicle are identical to one another. The vehicle  10  may be balanced to foster movement of the third wheel  20  over the drive wheels  18 . For example, the rechargeable battery power source  28  may be located at least proximal to the one longitudinal end  19  of the chassis  12  and, preferably, at the one longitudinal end  19  of the chassis  12  on an opposite side of the common axis of rotation of the drive wheels (i.e. the central axis of axle  38 ) from the third wheel  20 . It is thus located as far away from the third wheel  20  as possible to counterbalance the weight of the third wheel  20 , moving the center of gravity of the vehicle  10  longitudinally closer to axle  38 . The three wheel design also adds to play value as the longitudinal end  19  with the third wheel  20  effectively has only a central area of contact which is relatively narrower than that of the opposite end  17  with the two spaced areas of contact provided by drive wheels  18 . There is a greater tendency for the vehicle  10  to rotate in its major plane (i.e. horizontal plane between major sides  14 ,  16 ) when the third wheel  20  strikes an obstacle in other than a perpendicular orientation to the obstacle than if the drive wheels  12  were to strike the same obstacle. The rebounding characteristics can further be changed by varying the pressure of the tire of the third wheel  20 . 
     The vehicle  10  is used with a hand operated remote control unit  11  (typically having a pair of manual controls  112 , one for each motor, and control and radio transmission circuitry, which is conventional as shown in U.S. Pat. No. 5,667,420. Independent motor control permits “tank steering” of the vehicle including the ability to essentially spin in place about an axis centered between the drive wheels  18  due to the balance of the vehicle. 
     The tires  90  of the drive wheels  18  are preferably formed from Kraton™ rubber (a styrene-butadiene-styrene polymer) and the tire  78  of the third wheel  20  is preferably formed from natural rubber. The chassis  12  components, including the support arms  32 ,  34 , the bottom housing  56 , the top panel  58 , the gear box covers  60  and  62 , and the battery box  64  are preferably formed from ABS plastic. Likewise, the hubs  46  of the drive wheels  18  and the conical hubs  80 ,  82  of the third wheel  20  are preferably formed from ABS plastic. All of these aforementioned plastic components are preferably formed by injection molding techniques well known to those skilled in the art. From this disclosure, it would be obvious to one skilled in the art to substitute other materials (e.g., other plastics, rubber, or metal) and other fabrication techniques (e.g., machining or stamping) for the materials and fabrication techniques preferably used. Similarly, from this disclosure, it would be obvious to one skilled in the art to substitute other proportions (e.g., a wider or longer toy vehicle  10 ) for those shown in the preferred embodiment. 
     It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.