Abstract:
An amusement ride vehicle capable of generating a natural “wheelie” motion with minimal acceleration is provided. Air springs are used to balance the vehicle about a predetermined center of gravity after passenger loading. The amount of balancing required is minimized by using a link, such as a pivoting control arm, to connect the front wheels of the vehicle to the front end of the chassis, thus enabling the chassis to be automatically balanced independent of the weight of the front wheels, without the need for computer control. Upon acceleration of as little as 0.5 Gs in a forward direction, the front end of the chassis rises smoothly and naturally into a upward arc while the front wheels remain engaged with the trackway. The amount of upward movement is limited by the length of the control arms, and can be further limited using stops, such as jounce and rebound bumpers. Passengers are loaded into the vehicle, and then the front end of the vehicle is levelled to compensate for the added weight of the passengers, for example by filling air springs mounted between the chassis and the front wheels. When the vehicle is levelled, the vehicle is accelerated to cause the front end of the chassis to rise up, “popping a wheelie.” As the ride decelerates, the front end drops down to a design height. Since vehicle acceleration causes the wheelie, it is by definition a natural force. This natural wheelie motion transmits the correct feel to the passengers.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to the field of amusement rides. More particularly, the present invention relates to dragster-type amusement rides. 
     BACKGROUND OF THE INVENTION 
     The sport of dragster racing typically involves two vehicles racing against each other on two straight, parallel racing tracks. At one end of the track is a designated starting line and at the opposite end of the track is a designated finish line. A winning vehicle is one that reaches the finish line within the shortest time period. The race commences with the vehicles accelerating from a stationary start. During the sudden acceleration of the vehicles from the starting line, the front ends of the dragsters often raise from the ground. The action which results when the front end lifts during acceleration is commonly referred to as a “wheelie”. The rapid acceleration combined with a wheelie makes dragster racing a thrilling experience. Unfortunately, a dragster is an inherently dangerous vehicle during a “wheelie” because the entire front end is lifted off the roadway, making the vehicle unstable, very difficult to control, and a hazard to its occupants and any bystanders. 
     In a continuing quest to provide thrilling and unique experiences, others have created amusement rides which attempt to simulate the sensation of being in a drag race while eliminating the danger inherent in operating a dragster. None of these rides have been successful in generating an authentic feeling “wheelie.” 
     For example, U.S. Pat. No. 5,522,321, issued to MOSLEY et al. discloses a dragster ride featuring bungee cord acceleration and deceleration structures. 
     U.S. Pat. No. 4,991,514, issued to POWELL et al. discloses a ride simulating a drag race in which each vehicle is accelerated by a linear induction motor. 
     U.S. Pat. No. 5,361,705 to POWELL discloses an electrically powered drag racing ride, including a special effects generator for generating sound, hydraulic shaking, and smoke at appropriate times. 
     Although each of these patents attempts to simulate the thrill of a real dragster race, none of them discloses a means by which to incorporate the “wheelie” motion into the ride. U.S. Pat. No. 3,840,241 to HOCK discloses a sled for sliding on low friction surfaces, such as snow or ice, provides a mechanism for manually raising the front frame of the sled off the ground, generating a sensation similar to that experienced with a “wheelie”. However, this sensation is created by the rider pushing against a control bar, and is thus expected, and not as thrilling as a wheelie which is automatically generated by acceleration. 
     Accordingly, the need exists for a dragster-type amusement ride which permits the front end of the vehicle to rise up automatically to generate a wheelie when a predetermined acceleration occurs, without the accompanying hazards of a dragster vehicle. 
     SUMMARY OF THE INVENTION 
     The present invention is a dragster-type amusement ride that simulates a wheelie automatically during acceleration. An objective of the present invention is to achieve this result at a much lower acceleration than would normally be possible with conventional vehicles. Further objectives of the present invention include creating a vehicle that can provide the same “wheelie” effect independent of the passenger loading conditions. 
     In one embodiment, the present invention provides an amusement ride vehicle for riding along a trackway. The vehicle includes a chassis with a front end and a rear end, a passenger compartment mounted on the chassis for seating at least one passenger, a guidance means for engaging the trackway and for guiding the vehicle along the trackway, a means for accelerating the vehicle in a forward direction along said trackway; and, a means for automatically levelling the chassis (i.e., balancing the chassis about a predetermined center of gravity located at or near the rear end of the chassis) after passengers have been seated in the passenger compartment, so that a natural feeling “wheelie” will be automatically induced when the vehicle is accelerated in a forward direction above some minimal value, such as at least about 0.5 Gs. 
     In another, more preferred, embodiment the present invention provides an amusement ride simulating a dragster race, including a trackway having a guide rail defining a ride path, and a vehicle for traveling on the trackway, the vehicle including a chassis having a front end and a rear end, a passenger compartment mounted on the chassis for seating at least one passenger, a guide rail engagement means mounted to the vehicle for engaging the guide rail, two drive wheels mounted to a drive axle for rotation, the first drive wheel located at a right rear end of the chassis and the second drive wheel mounted for rotation at a left rear end of the chassis, the drive wheels for propelling the vehicle along the trackway, a motor means mounted to the chassis for rotating the drive wheels about an axis, an automaticlevelling mechanism mounted between the guide rail engagement means and the chassis for raising the front end of the chassis to balance the chassis about a center of gravity located at or near the drive axle to compensate for passenger loading conditions so that wheelies can be generated independent of passenger loading, and without affecting the engagement between the guide rail and the guide rail engagement means. A means for limiting the upward movement of the front end of the chassis during a “wheelie” is also most preferably provided for safety reasons. When the vehicle is accelerated on the trackway to a predetermined level, the front end of the chassis rises up automatically in a natural arc about the axis of the rear wheels until it reaches an uppermost limit. The front end of the chassis will remain at this uppermost limit for so long as the vehicle continues to accelerate above the predetermined minimum value. When the vehicle decelerates below this value, the front end of the chassis will automatically return to its starting position. 
     These and other objects of the invention will become apparent from the Detailed Description of the Invention, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partially sectioned, side view of a vehicle and track of the present invention; 
     FIG. 2 is an exploded, perspective view of a preferred vehicle and track of the present invention; 
     FIG. 3 is an exploded, perspective view of an alternative vehicle and track of present invention; 
     FIG. 4 is a cut away side view of a front end of the vehicle shown in FIG. 1; 
     FIG. 5 is a different cut away side view of a front end of the vehicle shown in FIG. 1; 
     FIG. 6 is a schematic of a pneumatic system for leveling a vehicle of the present invention; and, 
     FIG. 7 is a side view of a vehicle of the present invention illustrating the wheelie motion. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention simulates the “wheelie” motion experienced by a dragster driver during rapid acceleration, without the danger inherent in operating a dragster. 
     The Trackway 
     A vehicle of the present invention is preferably mounted for acceleration along a trackway, such as the conventional, single support or load rail  8  as shown in FIGS. 1-3. Load rail  8  can be any suitable, conventional rail. We prefer a rail having a substantially circular cross-section as is typically used in modern roller coasters. Support rail  8  is supported conventionally above a surface, typically concrete, to which the rail  8  is mounted, using conventional rail support brackets  16 . In the preferred embodiment, two driving surfaces  9 ,  9 ′ are provided along each side of the support rail  8  to form a roadway. Support rail  8  is preferably positioned so that its longitudinal central axis is located in or near the plane of driving surfaces  9 ,  9 ′ as shown in FIG.  1 . In addition, in the preferred embodiment, where vehicle  1  is provided with an electrical propulsion system, one or more electrical conductors can be provided along load rail  8 . In the preferred embodiment, shown in FIG. 2, a conventional electric bus bar  3 ,  3 ′, is mounted along each side of the load rail  8 . However, a single bus bar mounted along one side of the load rail, or any other conventional conductor mounted at any position where it can be accessed by a vehicle in motion along the roadway, will also work. The trackway may be conventionally laid out with a loading station at one end and an unloading station at an opposite end, or in an endless loop with one or more loading and unloading stations positioned alongside the loop for loading and unloading passengers. 
     Less preferably, the trackway may be constructed in any conventional manner designed to keep a vehicle on the roadway during operation. For example, a conventional roadway formed from substantially smooth asphalt or concrete path like a roadway can be provided with guide rails, ridges, or similar barriers extending upwards from the roadway (for coacting with the inside surface of the vehicle wheels), or alongside the roadway (for coacting with the outside surface of the vehicle wheels or vehicle body) for preventing the wheels of the vehicle from moving laterally off the roadway. See, e.g., U.S. Pat. No. 5,595,121, which is incorporated herein by reference, for other possible configurations. 
     The Vehicle 
     As shown in FIGS. 1-3, vehicle  1  includes a front end  5 , a rear end  6 , and a chassis  15  to which is attached a vehicle body  13 , including a passenger compartment having one or more passenger seats  14 ,  14 ′,  14 ″,  14 ″′. Passenger seats  14 ,  14 ′,  14 ″,  14 ″′ are preferably provided with conventional passenger restraints. Passenger restraints which automatically lower or lock to secure each rider in the seat at the beginning of the ride, and raise or unlock as the vehicle comes to a stop at the end of the ride to permit unloading of passengers are preferred. However, manually engageable and disengageable passenger restraints, such as seat belts, may also be used. While passenger restraints are not required for generating a wheelie, they are preferred for obvious safety reasons. 
     As shown in FIGS. 1-3, chassis  15  preferably includes, near each end  5 ,  6  of vehicle  1 , a wheel assembly for moving the vehicle  1  on the load rail  8 . The front wheel assembly  17  and the rear wheel assembly typically include a pair of load wheels  11 ,  11 ′ for running along the top surface of the load rail  8 , transmitting a substantial portion of the load of the vehicle and passengers to the load rail  8 . More preferably, the weight of the rear end  6  of the vehicle is carried by drive wheels  7 ,  7 ′, eliminating the need for load wheels  11 ,  11 ′ in the rear wheel assembly. 
     Each wheel assembly also most preferably includes four guide wheels  12 ,  12 ′,  12 ″,  12 ″′, mounted so that two guide wheels  12 ,  12 ′ are located along a first side of the load rail  8  and two guide wheels  12 ″,  12 ″′ are located along an opposite, second side of load rail  8 . The purpose of the guide wheels  12 ,  12 ′,  12 ″,  12 ″′ are to guide the vehicle  1  along the load rail  8 , and to prevent the load wheels from slipping laterally off the load rail  8 . While less preferable, it would be possible to reduce or increase the number of load wheels or the number of guide wheels to achieve a similar result. 
     Chassis  15  also preferably includes a pair of drive wheels  7 ,  7 ′ at or near the rear end  6  of the vehicle for propelling the vehicle  1  along the driving surface  9 ,  9 ′. Drive wheels  7 ,  7 ′ are preferably mounted to an axle extending across the rear portion of the chassis  15  from right to left, with drive wheel  7  mounted to the right end of the drive axle, and drive wheel  7 ′ mounted to the left end of the drive axle. Drive wheels  7 ,  7 ′ are driven by motor  2 , which is most preferably an electric motor. Alternatively, motor  2  could be any conventional propulsion means, such as an impulse, gasoline or diesel motors. Less preferably, drive wheels  7 ,  7 ′ could each be mounted to a separate axle, as shown in FIG. 3, and vehicle  1  could be propelled by a plurality of motors. 
     Drive wheels  7 ,  7 ′ are preferred because they simulate the appearance and action of the rear end of a dragster. While less preferable, it would be possible to eliminate the drive wheels altogether and adopt another conventional drive system such as, for example, that disclosed in U.S. Pat. No. 5,595,121, or to use a more conventional vehicle like an automobile with four wheels operated on a trackway with guide rails, ridges or other barriers to prevent the wheels from leaving the trackway. 
     In the preferred embodiment, two or more conventional bus bar shoes  10 ,  10 ′ can be mounted to the chassis in a position to place them in contact with bus bars  3 ,  3 ′ when the vehicle  1  is positioned for movement along the load rail  8 . To transfer electricity from the bus bars  3 ,  3 ′ of the preferred embodiment,. Bus bar shoes  10 ,  10 ′ are connected conventionally to transfer electricity to motors  2 ,  2 ′. 
     To achieve a natural wheelie motion at a low acceleration, the weight distribution of the vehicle is an important consideration. Weight must be allocated so that a reasonably small acceleration will allow the front end  5  of vehicle  1  to easily and naturally pivot upward, most preferably about an axis  18  (shown in FIGS. 2-3) passing through the drive wheel axles. To help achieve a proper distribution of mass which will enable an easy generation of a wheelie during relatively low acceleration, the vehicle components are preferably arranged so that, when average passenger loading is taken into consideration, the vehicle is balanced about the axis  18  passing through the drive axle. To adjust for the differences between the average passenger loading and the actual passenger loading, the present invention contains a means for balancing or levelling the vehicle about the longitudinal axis  18  passing through the center of the drive axle. 
     The levelling process is most preferably carried out using at least one air spring  20 , shown in FIG. 2, located near the front end  5  of vehicle  1 , most preferably over the front wheel assembly  17 , for adjusting the position of the chassis  15  relative to the front wheel assembly  17 . Air springs preferred for use in this invention are those typically used on semi-tractor trailers, such as, for example, Firestone Part No. 1T12E-3. While one airspring is preferred, it would also be possible to use two or more airsprings for achieving the same result. Likewise, devices other than airsprings, such as mechanical torsion springs, although not preferred can be used to adjust the front end of the vehicle and should, accordingly, be considered as within the scope of the present invention. 
     As shown in FIGS. 2 and 6, air spring  20  is charged using compressed air to level the chassis. Preferably, air is supplied by the compressor  21  at about  120  pounds per square inch (“psi”) to air receivers  25  for storing compressed air for use during leveling in addition to air supplied directly by the compressor  21 . Receivers  25  supply high volumes of air to reduce the leveling sequence time. During the leveling process, air is passed from compressor  21  and air receivers  25  to air spring  20 . Initially, a lower limit valve  22  (a mechanical limit valve) can be actuated allowing air to pass into spring  20 . As the air pressure in each air spring  20 ,  20 ′ is increased, the front end  5  of vehicle  1  raises. When vehicle  1  reaches a predetermined level, an upper limit valve  23  (also a mechanical limit valve) can be activated. This valve  23  stops the flow of air. If the level of the front end  5  is initially too high (i.e. passenger loading is too light), the upper limit valve  23  should exhaust enough air to lower vehicle  1  to its proper height. The trip point position of upper and lower limit valves  23 ,  22  (respectively) can be subsequently adjusted to provide the sufficient leveling pressures to air spring  20  such that the chassis raises just off its jounce bumpers when properly leveled. Jounce and rebound bumpers provide stops for limiting the wheelie motion generated after balancing vehicle  1  when vehicle  1  is subjected to acceleration and cushion ends of travel stops. 
     Upper and lower limit valves  23 ,  22  (respectively) are preferably connected to a first solenoid valve  26 , which will only allow limit valves  22 ,  23  to function during the leveling process, and will turn them off so that they cannot function during the ride. Deactivating valves  22 , 23  will prevent further adjustment as the vehicle begins moving down the track and generates a wheelie. Once the ride is completed, the passengers have been unloaded, and new passengers have been loaded, solenoid valve  26  receives an electrical signal, reactivating the lower and upper limit valves  22 , 23  to again initiate the leveling process. 
     Preferably, an expansion tank  25 ′ is connected to the two air springs  20  in the preferred embodiment. The purpose of expansion tank  25 ′ is to increase the effective volumetric air capacity of air spring  20 . By increasing the effective air volume, the force generated by air spring  20  remains more constant during the wheelie. If expansion tank  25 ′ was not used, the wheelie motion would be less natural under some loading conditions. 
     While air spring  20  is most preferred, other conventional means for raising and lowering the front end  5  of the vehicle chassis to compensate for actual passenger loading which differs from average passenger loading can also be used. 
     As shown in FIGS. 2 and 5, one or more shock absorbers or dampers  33  can be installed in series with the air spring  20 . Shock absorber  33  dampens the wheelie motion making vehicle  1  raise and lower smoothly. Shock  33  can be tuned to finely adjust the feel of the wheelie motion. This “tuning” can be accomplished through initial shock design, or by using a conventional, externally adjustable shock to adjust the damping rates relative to the jounce and rebound bumpers. 
     As shown in FIGS. 2-5, two control arms  30 ,  30 ′ are preferably provided for control of the wheelie. Control arms  30 ,  30 ′ can be pivotally mounted at one end ( 30   a ) to the chassis  15  at the front end  5  of vehicle  1 , and at the other end ( 30   b ) to the front wheel assembly  17 . More preferably, the front end of chassis  15  is formed by a spring perch  19  and yoke  24 , as shown in FIG. 3, and end  30   a  is pivotally mounted to chassis  15 , while end  30 ( b ) is mounted to spring perch  19 . The control arms  30 ,  30 ′ control the upward movement of the front end of vehicle  1 , while the front wheel assembly  17  remains in engagement with rail  8 . The amount of vertical travel is limited by the length of control arms  30 ,  30 ′ and can be further limited in the preferred embodiment by the position of the jounce and rebound bumpers. This control arm configuration is particularly preferred for functional and safety reasons, since the front end of passenger compartment  13  of vehicle  1  moves upward during the wheelie, but the relatively heavy front wheel assembly  17  remains on track  8 , as shown in FIG.  7 . Since front wheel assembly  17  does not move upward during the wheelie motion, its weight is not included in the levelling/weight balancing which is required to place the vehicle in condition to perform a wheelie at low acceleration rates. 
     Spring perch  19  and yoke  24 , shown in FIG. 3, are preferred because they provide additional degrees of freedom in the vertical and horizontal axes. If vehicle  1  travels on a vertically or horizontally curved track  8 , these additional degrees of freedom enable vehicle  1  to negotiate compound curves in the vertical and horizontal axes. While preferred, spring perch  19  and yoke  24  not necessary to produce a natural wheelie motion upon acceleration, and are not needed if vehicle  1  moves along a straight track. 
     The present invention does not require computer control or sensing for normal operation of the air spring balancing mechanism. However, in the preferred embodiment electrical signals will typically be needed to activate the means for balancing the chassis (i.e., the airsprings and associated solenoids, limit valves, compressor and air receivers) during the leveling sequence, to run and stop the vehicle, for discharge/unloading and/or preparing the vehicle for loading. Such electrical signals can, of course, be generated by any conventional means such as, for example, conventional ride control switches controlled manually by a ride operator, a central ride controller for automatically transmitting the correct signal to the appropriate component on the vehicle, or by a vehicle controller in electrical communication with the solenoids. Where a vehicle controller is used, communication may be established using any conventional transmitter/receiver capable of communicating with the ride controller for controlling the movement of multiple vehicles on a single track. See, e.g., U.S. Pat. No. 5,595,121 for examples of how this can be accomplished. In the preferred embodiment, once the means for balancing the chassis has been activated by an electrical signal, it operates to automatically balance the front end of the vehicle to a position between the limit valves and then shut off (before the vehicle begins to move down the track). A ride computer will then preferably control the speed of the vehicle on the track, braking, and the spacing between multiple ride vehicles where more than one vehicle is mounted for movement along the track. 
     Operation of the Ride 
     Vehicle  1  of the preferred embodiment is positioned at a loading platform so that the load wheel assembly  17  engages rail  8  and drive wheel  7  rests atop driving surface  9  and drive wheel  7 ′ rests atop driving surface  9 ′. Passengers are seated in one or more of seats  14 ,  14 ′,  14 ″,  14 ″′, and a restraining system is most preferably engaged to secure each passenger to his or her seat. Once the passengers are all seated and secured, the front of the vehicle is balanced to compensate for the differences, if any, between the actual passenger loading and the average passenger loading used initially to balance the vehicle about the longitudinal axis  18  passing through the drive axle. To start this process, an electrical signal is generated either manually (e.g., by an operator throwing a switch), or automatically (e.g., by a controller), to open the solenoid valve  26 . The position of the vehicle chassis relative to the front wheel assembly actuates the limit valves. Therefore, actual passenger loading is compensated for by precharging the air spring by allowing air to pass into the air spring (and expansion tank if present) from an air receiver and/or a compressor. As the air spring&#39;s pressure is increased, the front of the vehicle raises until it reaches an upper limit determined by the upper limit valve (a mechanical limit valve), at which point the air flow is stopped by the upper limit valve. The upper and lower limit valves can be adjusted so that the chassis raises just off the jounce bumpers. 
     Once the vehicle has been levelled, the first solenoid shuts off the upper and lower limit valves to prevent their operation during the ride. A signal is sent to activate motor  2  which rotates drive wheels  7 .  7 ′, moving vehicle  1  away from the loading platform along rail  8 . As shown in FIG. 7, when a predetermined acceleration is reached, front end  5  automatically rotates upwardly about axis  18  to pop a “wheelie” as the vehicle continues moving down the track  8 . For example, an acceleration rate of 0.5 g, which is much lower than the several g&#39;s of acceleration required for normal drag race cars, should easily cause vehicle  1  to wheelie. The upward movement of front end  5  of the preferred embodiment is dampened by shock absorber  33  to create a very smooth and natural feeling motion, and is limited by jounce and rebound bumpers, although the length of the control arms will also limit and control the upward movement of front end  5 . The vehicle  1  continues along the track, accelerating to pop a wheelie, and decelerating to allow the front end to drop down, until the end of the ride is reached. At the end of the ride, the vehicle comes to a stop, the passenger restraint system is released/deactivated, and the passengers step out of the vehicle. 
     Of course, it would be possible to provide an acceleration control inside vehicle  1  to allow one or more passengers to manually accelerate the vehicle to a predetermined value sufficient to cause a wheelie when desired. Alternatively, where an on-board controller is provided, the controller can be programmed to produce sudden and unexpected accelerations (and their accompanying wheelies) to increase thrill. Furthermore, it would be possible to lay out multiple parallel trackways to allow passengers to “race” their vehicle along their trackway against passengers on other trackways, as is done in a real drag race. 
     The present invention has been described in terms of the preferred embodiment. One skilled in the art will recognize that it would be possible to modify the arrangement of the components in a variety of ways. One skilled in that art will also recognize that equivalent elements could be used to achieve the same results of the present invention.