Patent Application
20060254841
The present invention generally relates to road vehicles, off-road vehicles, or all-terrain vehicles (ATVs) suitable for traveling over even or uneven terrain in various environments. The present invention more particularly relates to vehicles such as, for example, automotive vehicles, recreational vehicles, snowmobiles, agricultural vehicles, utility vehicles, construction vehicles, military vehicles, or robotic vehicles.
A “zero turn” (ZT) vehicle, as is commonly known in the art, will in some embodiments typically include, for example, a frame, a power source, a body, a primary axle assembly, two drive wheels, and two dolly wheel assemblies. The power source is commonly mounted to the central or rear portion of the frame and typically includes, for example, at least one engine or motor. The body, too, is mounted to the frame and is suitable for carrying a human load, for example, the vehicle operator, and an object load as well. The primary axle assembly is also mounted to the frame. In particular, the primary axle assembly is typically mounted to the rear portion of the frame such that the primary axle assembly is aligned substantially orthogonal to the length of the frame. The two drive wheels, in turn, are rotatably mounted on the ends of the primary axle assembly such that the drive wheels are aligned substantially in parallel and are in mechanical communication with the power source. To facilitate ease in vehicle movement and travel, the two dolly wheel assemblies, lastly, are typically mounted to the front portion of the frame. In such a configuration, the two drive wheels are capable of facilitating both driving and moving interaction with the ground. The two dolly wheel assemblies, however, merely cooperate with the two drive wheels in generally maintaining the overall balance of the vehicle as the vehicle travels over the ground.
As is uniquely characteristic of a ZT vehicle, the two drive wheels are particularly rotatably mounted to the primary axle assembly so that they each have independent drive capability. That is, both the speed and the direction of rotation of the two drive wheels are controlled independently from each other as dictated by the vehicle operator through the delivery of power from the power source. In this way, steering the vehicle in a desired direction of travel is successfully accomplished by the vehicle operator through independently varying, as necessary, the rotational speed and direction of each drive wheel. As a result, a ZT vehicle is much more highly maneuverable as compared to automotive vehicles incorporating more traditional linkage or rack-and-pinion front axle steering systems. In particular, a ZT vehicle is virtually capable of “turning on a dime” and therefore has an overall vehicle turning radius of zero. The two ground-interacting dolly wheels associated with the two dolly wheel assemblies are each swivel mounted to the frame and rotatable such that they both merely cooperate with the two drive wheels in maintaining the overall balance of the vehicle as the vehicle travels over the ground. Thus, the two ground-interacting dolly wheels themselves are, by design, not capable of being directly steered by the vehicle operator.
Although a ZT vehicle has the inherent advantage and desirable characteristic of having such zero turn capability, a ZT vehicle also has some inherent disadvantages and undesirable characteristics as well. For example, if, as opposed to traveling directly up or directly down the side of a hill, a ZT vehicle is instead traveling across the side of a hill, the front portion of the vehicle naturally tends to pull the front end of the vehicle sideways and downhill. Such a tendency is due in respective part to three reasons. First, the typical ZT vehicle, as described hereinabove, is commonly weighted at its front end in order to maintain vehicle stability when driving up steep inclines. Second, the typical ZT vehicle, as described hereinabove, includes two ground-interacting dolly wheels mounted to the front portion of the frame that provide no directional stability for the front end of the vehicle. Third, since the “uphill” drive wheel of the vehicle naturally has less traction than the “downhill” drive wheel of the vehicle due to the incline of the hill effectively shifting more of the vehicle weight to the downhill drive wheel, the uphill drive wheel is prone to losing traction and therefore slipping. When such slipping occurs, the directional stability normally provided by the uphill drive wheel is lost, thereby causing the front end of the vehicle to be gravitationally pulled sideways and downhill.
To help correct the problem associated with traveling across a hillside, engineers commonly prescribe designs for ZT vehicles wherein most of the overall weight of the vehicle is shifted further back along the length of the frame. In doing so, most of the vehicle weight is thereby particularly centered just in front of and over the primary axle assembly. As a result, improved traction of the two drive wheels mounted on the ends of the primary axle assembly is realized and less pull at the front end of the vehicle is also realized whenever the vehicle travels across a hillside. However, a problem sometimes arises when the ZT vehicle attempts to travel directly up a steep hill. In particular, if the incline of a hill is sufficiently severe, the front end of the ZT vehicle comes off the ground as the overall weight and center of gravity of the vehicle shifts rearward and beyond the points of contact between the two drive wheels and the ground. Furthermore, even if the incline of a hill is not so severe, a sudden burst of acceleration by the ZT vehicle as initiated by a vehicle operator while driving the vehicle also frequently causes the front end of the vehicle to come off the ground. In extreme cases of these two types of situations, the front end of the ZT vehicle sometimes comes off the ground to the extent that the vehicle is altogether upended.
In order to remedy the problem associated with traveling directly up a steep hill, most designs for ZT vehicles include either a “wheelie bar” (sometimes simply called a “roller bar”) or a skid plate. Such a wheelie bar or skid plate is mounted to the rear end of the vehicle frame to thereby prevent the vehicle from being altogether upended whenever the front end of the vehicle comes off the ground. The inclusion of one or both such remedial fixtures is reasonably effective in facilitating vehicle travel up a hill in cases where the front end of the vehicle infrequently and merely momentarily comes off the ground. However, such remedial fixtures have proven to be undesirable in cases where the front end of the vehicle comes off the ground for prolonged periods of time, for the fixtures in such cases give rise to drag that significantly inhibits rather than facilitates uphill travel.
To help eliminate the problems associated with traveling both across and up a hill, some engineers have designed ZT vehicles that include a manually adjustable ballast system. When used, such an adjustable ballast system has to, first of all, be manually preset. Once preset, the ballast system can then be effectively utilized onboard the vehicle, especially when traveling over long stretches of anticipated or known terrain with consistent topography or grade characteristics. However, such a manually adjustable ballast system has proven to be largely inconvenient to use when traveling over unanticipated or unknown terrain with extreme and everchanging topography or grade characteristics. Furthermore, such a manually adjustable ballast system has also proven to be largely inconvenient to use whenever frequent and significant changes in the human load and/or the object load onboard the vehicle are made.
In an attempt to correct the problem associated with traveling over extreme and everchanging terrain, engineers have designed ZT vehicles that include two elongated ground-interacting track assemblies. The two track assemblies are mounted to the frame of the vehicle such that the two drive wheels, or drives associated therewith, are engaged within the two track assemblies to thereby facilitate both driving and moving interaction of the two track assemblies with the ground. In such a configuration, dolly wheel assemblies are typically not included. Although such elongated track assemblies are effective in improving the overall fore-aft stability of the vehicle when traveling over extreme and everchanging terrain, the inherent elongated nature of the track assemblies undesirably limits, in some situations, the zero turn capability of the vehicle. In addition, given the typical variation in fore-aft (i.e., front-to-back) loading of a ZT vehicle, each elongated track assembly often fails to properly interact with the ground in an even pressure-distributed manner along its respective length, thereby undesirably negating a characteristic advantage of utilizing such elongated track assemblies on terrain with, for example, sand or snow.
To remedy the problem associated with designing a ZT vehicle that successfully travels over extreme and everchanging terrain without limiting the zero turn capability of the vehicle, some engineers have designed a ZT vehicle that includes a gyroscopic sensor system. In particular, the vehicle includes a system of multiple gyroscopic sensors electrically connected to one or more electronic controllers. The electronic controllers, in turn, are electrically connected to drive wheel motors which themselves are in mechanical communication with the two drive wheels. In such a configuration, the gyroscopic sensors continuously sense the attitude or balance condition of the vehicle as the vehicle travels over everchanging terrain. While doing so, the gyroscopic sensors also continuously communicate electrical vehicle attitude or balance condition information signals to the electronic controllers. The electronic controllers, in turn, then process the electrical vehicle attitude information signals, generate electrical control signals based on the vehicle attitude information, and communicate the electrical control signals to the drive wheel motors. The drive wheel motors then mechanically operate the two drive wheels in compliance with the electrical control signals received from the electronic controllers. In this manner, the gyroscopic sensor system attempts to continuously maintain the fore-aft stability and overall balance of the vehicle by regulating the fore-aft driving rotation of the two drive wheels underneath the vehicle such that the overall weight and/or load of the vehicle is generally centered and maintained over the primary axle assembly and drive wheels. Although such a ZT vehicle with gyroscopic sensor system is reasonably effective in maintaining vehicle balance under most conditions, such is only marginally effective under conditions of reduced traction. For example, if an area of ground on a hillside is significantly covered with sand, loose gravel, mud, water, snow, or ice, a ZT vehicle with gyroscopic sensor system sometimes has difficulty in maintaining its balance while traveling thereon. Such difficulty is due to the fact that good traction necessary for drive wheel movement to quickly correct any vehicle imbalance is not always available under such reduced traction conditions.
In light of the above, there is a present need in the art for a vehicle and/or a vehicle system that (1) successfully maintains vehicle balance when traveling directly up a hill, (2) successfully maintains vehicle balance when traveling across a hillside, (3) successfully maintains vehicle balance even when a vehicle operator attempts rapid acceleration or sudden braking, (4) successfully maintains vehicle balance when traveling over terrain with extreme and everchanging topographies, (5) successfully maintains vehicle balance and optimizes traction even when there are significant and frequent changes in human load and/or object load onboard the vehicle, (6) successfully maintains vehicle balance even under reduced traction conditions, (7) does not unnecessarily limit maximum zero turn capability in a ZT vehicle, and (8) is successfully applicable to both ZT vehicles and non-ZT vehicles as well.
The present invention provides a vehicle for traveling over ground with a load. In one practicable embodiment, the vehicle includes a body, an elongate frame, at least one vehicle-stabilizing element, an adjustable axle assembly, a pair of drive wheels, an actuation system, at least one attitude sensor, and an electronic controller. The body is mounted to the frame, and the frame has front and rear ends with a fore-aft axis extending therebetween. Each vehicle-stabilizing element is mounted at the front end of the frame, and the adjustable axle assembly is mounted at the rear end of the frame substantially orthogonal to the fore-aft axis. The drive wheels are rotatably mounted opposite each other at the ends of the adjustable axle assembly. The actuation system is capable of mechanically moving the adjustable axle assembly to thereby adjust the fore-aft position of the pair of drive wheels relative to the frame. The electronic controller is mounted to the body and electrically connected to the actuation system and each attitude sensor. In this configuration, each attitude sensor is capable of communicating electrical signals representing vehicle attitude data to the electronic controller. The electronic controller, in turn, is capable of communicating electrical control signals to the actuation system to thereby adjust the fore-aft position of the pair of drive wheels as necessary to actively maintain the fore-aft stability of the vehicle. In some embodiments, the electronic controller is particularly capable of communicating electrical control signals to the actuation system to thereby adjust the fore-aft position of the pair of drive wheels as necessary to actively maintain the vehicle standing and balancing on the pair of drive wheels with each vehicle-stabilizing element lifted off the ground.
In another practicable embodiment, the vehicle may include a body, an elongate frame, at least one vehicle-stabilizing element, an adjustable axle assembly, a pair of drive track assemblies, an actuation system, at least one attitude sensor, and an electronic controller. The body is mounted to the frame, and the frame has front and rear ends with a fore-aft axis extending therebetween. Each vehicle-stabilizing element is mounted at the front end of the frame, and the adjustable axle assembly is mounted at the rear end of the frame substantially orthogonal to the fore-aft axis. The drive track assemblies are mounted opposite each other at the ends of the adjustable axle assembly. The actuation system is capable of mechanically moving the adjustable axle assembly to thereby adjust the fore-aft position of the pair of drive track assemblies relative to the frame. The electronic controller is mounted to the body and electrically connected to the actuation system and each attitude sensor. In this configuration, each attitude sensor is capable of communicating electrical signals representing vehicle attitude data to the electronic controller. The electronic controller, in turn, is capable of communicating electrical control signals to the actuation system to thereby adjust the fore-aft position of the pair of drive track assemblies as necessary to actively maintain the fore-aft stability of the vehicle. In some embodiments, the electronic controller is particularly capable of communicating electrical control signals to the actuation system to thereby adjust the fore-aft position of the pair of drive track assemblies as necessary to actively maintain the vehicle standing and balancing on the pair of drive track assemblies with each vehicle-stabilizing element lifted off the ground.
Furthermore, it is believed that still other embodiments of the present invention will become apparent to those skilled in the art when the detailed descriptions of the best modes contemplated for practicing the invention, as set forth hereinbelow, are reviewed in conjunction with the appended claims and the accompanying drawing figures.
The present invention is described hereinbelow, by way of example, with reference to the following drawing figures.
To facilitate a proper understanding of the present invention, a list of parts and features highlighted with alphanumeric designations in
As illustrated in
In addition to both the frame 22 and the body 60, the vehicle 20A also includes a first embodiment 131A of the actively adjustable axle system 131 with a pair of rear drive wheels 56L and 56R. The actively adjustable axle system 131A itself includes a first embodiment 86A of the adjustable axle assembly 86, a first embodiment 90A of the actuation system 90, and the electronic controller 96. The adjustable axle assembly 86A, as particularly illustrated in
Given the adjustable axle assembly 86A as configured, the two rear drive wheels 56L and 56R are rotatably suspended from the two swing arms 110L and 110R proximate the distal ends 114L and 114R thereof As particularly illustrated in
To facilitate adjustment of the adjustable axle assembly 86A, the actuation system 90A includes a pair of telescoping cylinders 126L and 126R serving as left and right actuators. As particularly illustrated in
In addition to the frame 22, the body 60, the actively adjustable axle system 131A, and the two rear drive wheels 56L and 56R, the vehicle 20A further includes a pair of dolly wheel assemblies 46L and 46R. The dolly wheel assemblies 46L and 46R are mounted to the front portion of the frame 22 such that they cooperate with the two rear drive wheels 56L and 56R in generally maintaining the overall balance of the vehicle 20A as the vehicle 20A travels over the ground 103. As particularly illustrated in
As illustrated in
Also, as illustrated in
As particularly suggested in
Moreover, as illustrated in
Furthermore, as illustrated in
During operation, as the vehicle 20A travels over the ground 103, the electronic controller 96 receives electrical vehicle attitude information signals from the attitude sensors 102L and 102R, electrical load information signals from the load sensors 106L, 106R, and 106B, and electrical axle assembly position information signals from the position sensors 108L and 108R on a substantially continuous basis. As all of these electrical information signals are received, the electronic controller 96 promptly processes the electrical information signals. In doing so, the electronic controller 96 thereby attempts to actively determine and monitor the position of the center of gravity 100 of the vehicle 20A together with its cumulative onboard load in relation to the ground contact points of both the two dolly wheels 48L and 48R and also the two rear drive wheels 56L and 56R.
Given that the vehicle 20A in this particular embodiment is a ZT vehicle, the vehicle 20A and its component parts are specifically dimensioned, weighted, and assembled such that the overall center of gravity 100 of the vehicle 20A together with its load is naturally predisposed to being well behind the ground contact points of the dolly wheels 48L and 48R and just in front of and over the ground contact points of the two rear drive wheels 56L and 56R when the two rear drive wheels 56L and 56R are in a position forward of the midpoint of the adjustable axle assembly movement range and the vehicle 20A is traveling over ground 103 that is substantially level. In light of such purposeful dimensioning and center of gravity predispositioning, when the vehicle 20A is traveling over substantially level ground and the electronic controller 96 actively determines that the center of gravity 100 of the vehicle 20A together with its cumulative onboard load is safely situated behind the ground contact points of the two dolly wheels 48L and 48R and also in front of the ground contact points of the two rear drive wheels 56L and 56R, the electronic controller 96 will accordingly generate situation-specific electrical control signals and communicate the electrical control signals to the actuation system 90A. In response to the electrical control signals, the actuation system 90A will then mechanically adjust (i.e., pivot) the adjustable axle assembly 86A only if and as needed to thereby position the two rear drive wheels 56L and 56R in an optimal retracted (forward) fore-aft position as generally illustrated in
In situations, for example, where a vehicle operator fully anticipates traveling up a steep hill or firmly believes that the electronic controller 96 is receiving improper electrical information signals from a suspected malfunctioning sensor, the vehicle operator may opt to utilize the operator control panel 98 to manually enter operator preference input regarding his choice for moving the pair of rear drive wheels 56L and 56R into a particular fore-aft position. Once the vehicle operator enters his particular fore-aft position preference, electrical operator preference input information signals are communicated to the electronic controller 96. In response to receiving such electrical operator preference input information signals, the electronic controller 96 then ignores all other electrical information signals and promptly communicates electrical control signals to the actuation system 90A in accordance with the particular preference of the vehicle operator. As a result, the fore-aft position of the pair of rear drive wheels 56L and 56R is ultimately adjusted to maintain the fore-aft stability of the vehicle 20A according to the vehicle operator's best judgment. Thus, in this way, a vehicle operator can utilize the operator control panel 98 to manually override the actively adjustable axle system 131A of the vehicle 20A as desired and as necessary.
In summary, the first embodiment 20A of the vehicle 20 according to the present invention realizes many advantages over other off-road or all-terrain vehicles, and particularly ZT vehicles, commonly in use today. In particular, with its purposeful dimensioning, weight distribution, and predisposed center of gravity along with the actively adjustable axle system 131A, the vehicle 20A according to the present invention (1) successfully maintains its balance when traveling directly up a hill, (2) successfully maintains its balance when traveling across a hillside, (3) successfully maintains its balance even when a vehicle operator attempts rapid acceleration, (4) successfully maintains its balance when traveling over terrain with extreme and everchanging topographies, (5) successfully maintains its balance and optimizes traction even when there are significant and frequent changes in human load and/or object load onboard, (6) successfully maintains its balance even under reduced traction conditions, (7) is not unnecessarily limited in maximum zero turn capability when suited for use as a zero turn (ZT) vehicle, and (8) may successfully be adapted or suited for use as either a ZT vehicle or a non-ZT vehicle.
This concludes the detailed description of both the structure and operation of the first embodiment 20A of the vehicle 20 according to the present invention.
An alternative embodiment 131B of the actively adjustable axle system 131 is illustrated in
Another alternative embodiment 131 C of the actively adjustable axle system 131 is illustrated in
Still another embodiment 131D of the actively adjustable axle system 131 is illustrated in
In cooperation with such an actuation system 90B, the cross arm assembly 116 of the adjustable axle assembly 86A has a third embodiment 116C, as particularly illustrated in
Within such a configuration as depicted in
A slightly alternative embodiment 20B of the vehicle 20 is illustrated in
As clearly demonstrated in
Another alternative embodiment 20C of the vehicle 20 is illustrated in
This concludes the detailed description of both the structures and operations of alternative embodiments of the vehicle 20 according to the present invention.
While the present invention as described hereinabove was initially conceived in response to particular difficulties experienced with the performance and design of ZT vehicles, it is to be understood that the present invention is largely relevant and applicable to non-ZT vehicles as well. That is, many of the basic inventive principles implemented herein to improve the overall performance and design of ZT vehicles are applicable to many non-ZT vehicles as well. In particular, upon reading this invention disclosure, it is believed that one skilled in the art would readily realize that the inventive principles taught herein, for example, (1) actively determining the center of gravity of a vehicle with its cumulative onboard load to thereby maintain vehicle balance, (2) actively responding to shifts in vehicle attitude while the vehicle travels over extreme and everchanging terrain to thereby maintain vehicle balance, (3) actively responding to significant and frequent changes in human load and/or object load onboard the vehicle to thereby maintain vehicle balance, and (4) actively extending and/or retracting a two-wheeled axle of the vehicle as necessary to thereby optimize both vehicle maneuverability and vehicle balance, may also be applied to many non-ZT vehicles as well.
While having independent front or rear 2-wheel drive is primarily characteristic of ZT vehicles, it is to be understood that a vehicle pursuant to the present invention may alternatively have dependent front or rear 2-wheel drive capability, 4-wheel drive capability, or even all-wheel drive capability. In addition, with regard to suspension systems, a vehicle pursuant to the present invention may have an independent, non-independent, or semi-independent suspension system. Also, with regard to suspension system springs, a vehicle pursuant to the present invention may, as an alternative to coil springs, instead include leaf springs, air springs, or torsion bar springs. Moreover, with regard to vehicle steering systems, a vehicle pursuant to the present invention may, as an alternative to having two dolly wheels and two wheels with independent 2-wheel drive, instead have two largely non-steerable wheels and two wheels directly steerable with a traditional linkage or rack-and-pinion steering system. Furthermore, with regard to the actuation system, it is to be understood that many different types of actuators may alternatively be utilized on a vehicle pursuant to the present invention, including, for example, hydraulic, electric, pneumatic, or mechanical linkage type actuators, or even combinations thereof. Lastly, any actuation system incorporating one or more of such actuators may optionally be designed to adjust the fore-aft positions of vehicle wheels either together in pairs or independently and individually pursuant to the present invention.
In summary, the vehicle with actively adjustable axle system for traveling over uneven terrain with a load, as described hereinabove within its various preferred embodiments according to the present invention, realizes many advantages over other off-road or all-terrain vehicles commonly in use today. In particular, the vehicle according to the present invention (1) successfully maintains its balance when traveling directly up a hill, (2) successfully maintains its balance when traveling across a hillside, (3) successfully maintains its balance even when a vehicle operator attempts rapid acceleration, (4) successfully maintains its balance when traveling over terrain with extreme and everchanging topographies, (5) successfully maintains its balance and optimizes traction even when there are significant and frequent changes in human load and/or object load onboard, (6) successfully maintains its balance even under reduced traction conditions, (7) is not unnecessarily limited in maximum zero turn capability when suited for use as a zero turn (ZT) vehicle, and (8) may successfully be adapted or suited for use as either a ZT vehicle or a non-ZT vehicle.
A vehicle having a single primary axle with independent drive and speed control of each of the two wheels provides maneuverability known by those knowledgeable in the art as zero turn capability. Such a vehicle provides significant advantages in maneuverability, but has characteristics of operation that are unique to such a vehicle having a single axle that is utilized for both traction and steering control. There are adverse characteristics for this vehicle when operated on the sides of hills. This is particularly true when a heavier weighting of the front of the vehicle, which is generally supported by dolly wheels that provide no directional stability, results in a tendency for the heavier front weight to pull the front of the vehicle sideways and downhill. With the additional characteristic of the vehicle having less traction on the uphill drive wheel due to the side slope effectively shifting weight of the vehicle to the downhill drive tire, slippage of this uphill tire allows this undesired turning of the heavier front of the vehicle weight down the hill. In consideration of the tractive capability, which has direct impact on steering stability, the optimum drive and steering capability is achieved with the most weight being balanced on the single drive axle. In a rear drive unit, however, as weight is ideally placed over the single axle, the front axle has little weight, but enough for fore-aft stability on level terrain. When the vehicle encounters an upward slope, the center of gravity shifts rearward relative to the drive wheel contact point with the ground. This can result in the front of the vehicle coming off the ground. While this is often countered by use of a wheelie bar or rear skid plate for security reasons, it is unsatisfactory if a common occurrence, so more weight is then added to the front of the vehicle, thus lessening the desired tractive capabilities of the vehicle.
It is thus an advantage of the shifting axle system illustrated in applicant's co-pending patent application Ser. No. 10/610,485 to provide a vehicle with the ability to automatically and/or by on-demand power activation effect balancing of weight generally on the single drive axle and account for changes in the location of the center of gravity relative to that single drive axle which occurs when the vehicle encounters a slope or a change in vehicle loading, and account for the lift of the vehicle front that occurs when the vehicle accelerates rapidly.
There is a personal zero-turn vehicle system available that provides balance over one drive axle. In this vehicle, balance is maintained by a system of gyroscopic sensors in communication with controllers in communication with drive wheel motors such that the wheels rotate and drive such that they stay under the load. This system suffers in conditions of limited traction, such as in snow and ice conditions, where the instantaneous traction that is necessary for drive wheel movement to correct balance changes is not always available.
It is seen in Segway products that a vehicle having two axles can be made, by weight and force transfer of its human operator, to effect a “standing” of the vehicle on its one primary axle, balancing with utilization of the auto-balancing system through fore-aft rotation of the wheels to keep the wheels under the vehicle balancing above. The operator's weight or force transfer can similarly effect a return from “standing” operation of the vehicle to having both front and rear axles of the vehicle in contact with the ground.
A vehicle of heavy weight and size relative to operator weight and force capabilities could acquire advantageous maneuverability agility with such a “standing” mode, thereby allowing agile “zero-turn” for a vehicle with either a dolly wheel second axle or a standard steering secondary axle. However, there would be required a system for placing the vehicle's center of gravity over the “standing” axle in order to initiate the balancing of the vehicle within this mode, and to effectuate the transfer of the vehicle out of this mode and back into a two-axles-on-the-ground mode.
It would thus be advantageous to have the vehicle balancing capabilities that allow maximum traction of a zero-turn vehicle, but with the mechanical stability elements that allow all-weather and all-terrain capability. It would also be advantageous to have vehicle-balancing capabilities that allow the vehicle to “stand” on one axle for the purpose of enhanced maneuver agility. It would also be advantageous to have a vehicle combination of systems such that the vehicle is able to effectuate transfer in and out of these modes of vehicle stability without requiring weight or force transfer by a human operator.
To implement such advantages, the present invention further provides a fourth embodiment 20D of a vehicle 20 for traveling over ground 103 with a load, as illustrated in
In the same or other embodiments, the vehicle 20D may further include at least one load sensor 106 for sensing the position and weight of the load onboard the vehicle 20D, wherein the electronic controller 96 is electrically connected to each load sensor 106. In such a configuration, each load sensor 106 is capable of communicating electrical signals representing vehicle load data to the electronic controller 96. The electronic controller 96, in turn, is capable of communicating electrical control signals to the actuation system 90 to thereby adjust the fore-aft position of the pair of drive wheels 56L and 56R as necessary to actively maintain the fore-aft stability of the vehicle 20D.
Also, in the same or other embodiments, the vehicle 20D may further include at least one position sensor 108 for sensing the position of the adjustable axle assembly 86 onboard the vehicle 20D, wherein the electronic controller 96 is electrically connected to each position sensor 108. In such a configuration, each position sensor 108 is capable of communicating electrical signals representing axle position data to the electronic controller 96. The electronic controller 96, in turn, is capable of communicating electrical control signals to the actuation system 90 to thereby adjust the fore-aft position of the pair of drive wheels 56L and 56R as necessary to actively maintain the fore-aft stability of the vehicle 20D.
Furthermore, in the same or other embodiments, the vehicle 20D may further include at least one impact sensor (not illustrated) for sensing vehicle impact with an obstacle. In such an embodiment, the electronic controller 96 is electrically connected to each impact sensor so that each impact sensor is capable of communicating electrical signals representing vehicle impact data to the electronic controller 96. The electronic controller 96, in turn, is capable of communicating electrical control signals to the actuation system 90 to thereby adjust the fore-aft position of the pair of drive wheels 56L and 56R as necessary to actively maintain the fore-aft stability of the vehicle 20D.
As further illustrated in
In a fifth practicable embodiment 20E (not illustrated) of the vehicle 20 somewhat similar to the third embodiment 20C discussed earlier hereinabove, the vehicle 20E may include a body, an elongate frame, at least one vehicle-stabilizing element (for example, a ski), an adjustable axle assembly, a pair of drive track assemblies, an actuation system, at least one attitude sensor, and an electronic controller. The body is mounted to the frame, and the frame has front and rear ends with a fore-aft axis extending therebetween. Each vehicle-stabilizing element is mounted at the front end of the frame, and the adjustable axle assembly is mounted at the rear end of the frame substantially orthogonal to the fore-aft axis. The drive track assemblies are mounted opposite each other at the ends of the adjustable axle assembly. The actuation system is capable of mechanically moving the adjustable axle assembly to thereby adjust the fore-aft position of the pair of drive track assemblies relative to the frame. The electronic controller is mounted to the body and electrically connected to the actuation system and each attitude sensor. In this configuration, each attitude sensor is capable of communicating electrical signals representing vehicle attitude data to the electronic controller. The electronic controller, in turn, is capable of communicating electrical control signals to the actuation system to thereby adjust the fore-aft position of the pair of drive track assemblies as necessary to actively maintain the fore-aft stability of the vehicle. In some embodiments, the electronic controller is particularly capable of communicating electrical control signals to the actuation system to thereby adjust the fore-aft position of the pair of drive track assemblies as necessary to actively maintain the vehicle standing and balancing on the pair of drive track assemblies with each vehicle-stabilizing element lifted off the ground.
In brief, the present invention generally relates to vehicles or apparatuses with motion requiring stability at both higher speeds and in difficult terrain, and also requiring “zero-turn” agility or maneuverability in lower speed motion. The present invention further relates to vehicles or apparatuses of size and weight such that transfer between modes of stability is generally not possible to facilitate only by inputs of operator weight transfer.
The present invention generally is a combination of Segway technology and the shifting-axle technology of the Jake. This allows a larger vehicle of the Jake and JAICV platforms to have the stability of four wheels, yet be able to get into and out of a single-axle balancing mode for situations where greater maneuver agility is desired. This is like the Segway Centaur, but on the Centaur, the operator/rider provides the “lift” and weight shift required for the balance shift into the condition of balancing the vehicle on a single axle. The Jake solution is to use a shifting axle to work in concert with the balancing of the wheel systems, thereby facilitating ease of a smooth transition in and out of a single-axle (i.e., standing) mode.
It is understood that on a larger vehicle, the operator's weight is unable to effectuate significant shift in vehicle balance, yet the shifting axle system can rapidly alter the center of gravity, thus placing the vehicle weight into a balancing position over a single axle, where this balanced condition can then be maintained at a desired inclination of the vehicle such that a forward or a rearward axle generally provided ground contact for stability is thus removed from contact purpose of rapid turn agility.
It is to be understood that this same technology and feature combination can be applicable to a bicycle or motorcycle for the creation of a unicycle, and the transition from use in either unicycle or bicycle stance on the road for effecting desired stability and maneuver capabilities.
It is an object of the present invention to provide a pivotally mounted drive axle system that allows powered movement of the axle system forward and rearward relative to the vehicle and that works in concert with a balancing system that is able to actively balance the vehicle on the axle system when the weight of the vehicle is shifted to be over the balancing axle system.
It is a further object of the present invention to provide a moveable balancing axle system that carries a suspension for the individual drive wheels of a vehicle.
It is to be understood by those knowledgeable in the art that the drive axle suspension could also be dependent and utilize the adjustment controls as component of the suspension.
It is further an object of the present invention that the moveable balancing axle system is in communication with an electronic controller having sensors capable of sensing change of slope, obstacle impacts, and vehicle loading such that the sensors, in electrical communication through the electronic controller, effectuates a combination of balancing movements of the moveable balancing axle system to adjust the weight balance of the vehicle above the axle such that the vehicle maintains desired fore-aft stability.
It is further an object of the present invention that the moveable balancing axle system is applicable equally to a variety of tires or tracks as the ground engaging component. It is further an object of the present invention that the moveable balancing axle system may incorporate fixed-mounted drive wheels, independent “A” arm type suspension-mounted drive wheels, utilize a knee-action swing arm suspension component integral with the pivotally mounted drive axle, or other suspension method in conjunction with the moveable balancing axle system.
It is further an object of the present invention that the activation of the movable axle may be effectuated by a variety of methods such as hydraulic cylinder, electric actuator, electric linear motor, rotary actuator, mechanical linkage, and manual changes, as known by those knowledgeable in the art.
It is further an object of the present invention that control of the path and motion of the movable balancing axle may be accomplished by a variety of methods such as a pivoting system, a sliding system, or a mechanical linkage system, as known by those knowledgeable in the art.
It is further an object of the present invention that the moveable balancing axle and the balancing stability effects within the balancing axle system resulting from the appropriate movement of the axle relative to vehicle balance and drive wheel rotation maintaining balance, is able to account for operation on slopes, sudden acceleration or braking, or for changes in vehicle loading and is seen to be advantageous for application on vehicles of utility and/or mobility such as, for example, personal transportation vehicles, turf-care products vehicles, agricultural vehicles, construction vehicles, military vehicles, utility vehicles, and/or delivery vehicles.
The present invention of a moveable balancing axle system utilizes an controller to move a drive axle forward and rearward relative to the vehicle such that the relationship of the vehicle center of gravity relative to the centerline of the axle is changed for the purpose of moving full vehicle balance onto the moveable axle, whereupon it is there balanced, and not requiring the support provided by a front stabilizing element.
The moveable drive axle system may further be in communication with an electronic controller having associated sensors capable of sensing change of slope and vehicle loading such that the sensors, in electrical communication through the electronic controller, effectuate movement of the drive axle system to adjust the weight balance of the vehicle above the drive axle such that the vehicle maintains desired fore-aft stability.
It is claimed that the moveable balancing drive axle system is shifted by one or more of many methods understood by those knowledgeable in the art, and as outlined in U.S. patent application Ser. No. 10/610,485.
It is claimed that the moveable balancing axle system balancing is accomplished with the front of the vehicle maintained in a set degree of tilt, allowing the front wheels, or stability device, to be maintained off the ground with proper ground clearance for operation.
It is further claimed that the moveable balancing axle system balancing is accomplished with the front wheels, or stability device, of the vehicle being retracted, or lifted, in a manner to allow proper ground clearance for operation.
It is further claimed that the moveable balancing axle system may provide suspension by a variety of methods known to those knowledgeable in the art.
It is further claimed that control of the path and motion of the movable balancing axle may be accomplished by a variety of methods such as a pivoting system, a sliding system, a mechanical linkage system, and manual changes, as understood by those knowledgeable in the art.
It is further claimed that the path of the moveable axle may be configured to result in a significant and generally upward or downward movement of the vehicle relative to the balancing axle such that the vehicle body, when in the balancing mode, does not require a tilt to the vehicle or method of retracting or lifting the front in order to maintain ground clearance of the front of the vehicle for operation in the mode.
A suspension system of the drive wheels of the balancing axle to provide a cushioned ride for the vehicle, with the characteristics that the vehicle's fore-aft balance is not impacted, thus maintained with a minimum of stabilizing effort required by the vehicle. It is further claimed that the suspension system may utilize an active suspension system that anticipates and rapidly accommodates, or responds to, the obstacles or bumps in operation that the suspension is required for. It is further claimed that the suspension system utilizes an active linear motor type suspension to effect desired action for providing smooth ride of the vehicle without unduly affecting the balancing system of the vehicle.
It is further claimed that other vehicle-stabilizing elements or devices may include, for example, a dolly wheel system forward of the drive axle, a steered wheel system, a stationary prop, or a retracting prop.
Furthermore, it is claimed that the vehicle having the moveable balancing axle system is a vehicle having zero turn capability, as understood by those knowledgeable in the art, which is a vehicle steered through independently varying the speed and direction of rotation of its drive wheels.
In summary, a system for combining the controlled position of a vehicle axle and a balancing system within the axle for creating and maintaining a vehicle mode of operation balancing on the vehicle's primary drive axle is disclosed herein. A drive axle and its associated suspension is moved so as to provide an improved fore-aft vehicle stability by achieving a movement of the center of gravity of the vehicle relative to the drive axle. Advantage is realized with controlled movement of the axle accounting for stability when parked, operating in difficult conditions, and at high speeds. Such a moveable axle system is combined with a balancing system within the single axle system, such that when the vehicle weight is moved over the single axle, the ability exists to transfer vehicle stability to a balancing (i.e., standing) mode over this axle alone. This mode of operation can be entered and exited with ease without requiring a human operator to shift his weight. This invention is seen to be applicable to vehicles of utility and/or mobility such as, for example, personal transportation vehicles, turf-care products vehicles, agricultural vehicles, construction vehicles, military vehicles, utility vehicles, and delivery vehicles.
While the present invention has been described in what are presently considered to be its most practical and preferred embodiments and/or implementations, it is to be understood that the invention is not to be limited to the particular embodiments disclosed hereinabove. On the contrary, the present invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims appended hereinbelow, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as are permitted under the law.
The present invention claims priority from U.S. Provisional Application Ser. No. 60/683,001, originally entitled “Moveable Axle for Vehicle Stability,” which was filed on May 16, 2005.
| Number | Date | Country | |
|---|---|---|---|
| 60683001 | May 2005 | US |
