Patent Publication Number: US-6656065-B2

Title: Wheel mounted adjustable roller support assembly for a basketball goal system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates portable basketball goal systems. More specifically, the present invention relates to an apparatus for selectively engaging wheels to a surface to transport a portable goal system. 
     2. Description of Related Art 
     The game of basketball has become a popular sport in the United States and throughout the world. The number of professional and recreational basketball players has steadily increased through the past several decades. Unfortunately, in previous years, playing basketball has been limited to gymnasiums and outdoor courts, where expensive basketball equipment was available. However, as the popularity of the sport increased even more, the demand for access to basketball courts has increased. 
     For many players, the desire for basketball playing facilities has led to an increase desire for home basketball goal systems installed near a drive way or other playing surfaces. Home basketball goal systems typically are comprised of a backboard fastened to a wall, such as a garage, or fastened to a large metal pole anchored in the ground. 
     Unfortunately, installation of these basketball goal systems is difficult and obtrusive. For example, fixing a basketball goal to a wall often involves reinforcing that wall as well as making large holes in the wall to place the supporting fasteners. Often these walls are made of brick or stone which cannot be easily repaired when the basketball goal system is removed. Similarly problematic, a pole mounted basketball system involves digging a large hole adjacent to a playing surface, then filling that hole with cement while maintaining the pole in a vertical orientation. 
     Because of the amount of work and cost of obtaining a home basketball system, many potential players were unable to obtain easy access to a basketball goal system. Thus, only a selective ambitious few were able to play the sport of basketball at home. However, recent acknowledgment of these problems has produced a new line of freestanding basketball goal systems that are easy to install and relatively inexpensive. 
     Freestanding and portable goal systems are typically purchased in kit form and can be installed without mounting the system to a wall or into the ground. Instead, the freestanding goal systems are self supporting and can be assembled by a person having minimal mechanical skills. Typically, portable basketball goal systems comprise a base member, a pole, and a goal system. The base member is generally weighted to provide stability and support for the pole and goal system. 
     In efforts to increase the shipability and portability of the basketball goal systems, fillable ballast systems that receive a large massive water or sand to provide a weighted base were introduced. The water and sand ballast systems allow the base to be inexpensively shipped and easily transported. Furthermore, once the system was assembled at the home, the user could position the basketball goal system to any location in the yard and then fill the ballast system. 
     Unfortunately, these systems are only portable to the extent that they may be positioned to any location in yard when first assembled. Once the ballast is filled, the portable goal system becomes very difficult to move. Thus, portability within the yard or home playing surface is not as practical. In order for the player to move the goal system once the system is set up, the entire ballast must be emptied and then refilled when moved to the desired location. Such limitations have prevented true portability for home basketball systems. 
     A highly portable home basketball goal system may have many applications and uses for the everyday basketball player. For example, playing basketball in the morning and evening may often involve the sun hindering the view of the goal during one of the times. Players may desire to position that goal in one location for the morning at another location for the evening. However, players may be unwilling to go to extreme efforts to accomplish this. 
     Additionally, players may wish to move a basketball goal system to avoid temporary obstacles in the playing surface, such as a wet driveway or a parked car. Other basketball goal systems may need to be moved periodically for service or cleaning of the adjacent areas. For example, a basketball goals system positioned on grass may need to be moved periodically to cut the grass around the system as well as to provide the grass under the base member with sun and water. 
     Furthermore, some basketball players may not be inclined to have an entire goal system constantly located in their yard. It may be desired for the system to be placed in a garage or other storage area overnight, during poor weather, for the winter, or when entertaining guests. Unfortunately, the chore of breaking down the basketball system and emptying the ballasts to transport the basketball goal system is typically too burdensome for most people. As a result, basketball systems often remain in yards and driveways for months, while not being used. 
     To provide increased portability for some basketball systems, wheels have been introduced at the edges of a base. These wheels are often fixed to the base member and engage the playing surface when the entire basketball goal system is tilted back and the player balances the long pole during transportation. Unfortunately, these fixed wheel systems are difficult to use and have made little practical change with the portability problem. 
     Often the ballast of the base member contains 40 to 50 gallons of water or sand. The associated weight makes it very difficult to tilt back the goal system and maneuver the base to the desired location. Furthermore, the use of the pole as a lever arm to tilt the base, creates a high level of stress on the pole and also presents the possibility of the goal system falling and damaging the goal or injuring the player. Because of these and other shortcomings, basketball goal systems providing simple and rapid portability are not presently available. 
     Therefore, there is a need in the art for a portable basketball goal system that may be easily transported with minimal operations by the user. Such a system would be preferably inexpensive and provide simple user controls and adjustments. 
     SUMMARY OF THE INVENTION 
     The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available basketball goal systems. Thus, it is an overall objective of the present invention to provide a portable basketball goal system that may be transported with minimal effort by the user. 
     The portable basketball goal system comprises a pole, a base member, an adjustable wheel assembly, and an adjustment assembly. The pole is configured to support a basketball goal above a playing surface and the base member is configured to support the pole in a generally upward direction. The pole may be any number of cross-sectional shapes and configurations. The adjustable wheel assembly attaches to the base member, such that the wheel assembly can transition between a supported position and an unsupported position. In the supported position the wheel assembly selectively engages the playing surface. In the unsupported position the base member selectively rests on the playing surface. 
     The adjustable wheel assembly can transition between the supported and unsupported position by an adustment assembly. The adjustable wheel assembly transitions between the positions by the adjustment assembly comprised of a cam pivotally connected to the wheel assembly and an adjustment member to pivot the cam. The cam is configured to raise the base member relative to the axle as the cam pivots. As the base member elevates off of the playing surface the wheels become in supported contact with the playing surface. Once the wheels are in a supported position with the playing surface, the basketball goal system may be moved to various locations on the playing surface or in storage locations. 
     The cam of the adjustment assembly may pivot on the same axle as the wheels of the adjustable wheel assembly. The adjustment assembly may further comprise a second cam that is coaxial to the first cam. The additional cam or cams may be present to provide more contact area between the cam and the base member. The base member may also have a follower member that the cam contacts as the cam transitions with the base member between the lowered position and the elevated position. The follower may have varying shapes that provide the cam with a contact location to control the motion of the base member. 
     The cam may also have varying geometries to control the operational characteristics. In one implementation, the cam may have a stop that selectively engages the base member. The stop may prevent the cam from over rotating, such that the adjustment member does not contact the playing surface or the pole. Additionally, the cam may have multiple stable positions that allow the adjustment mechanism to snap to two or more positions. The two positions may correspond to the supported and unsupported positions of the wheel assembly or the elevated and lowered position of the base member. 
     The adjustable wheel assembly may also comprise a clevis. The clevis may be positioned under the base member, such that the axle of the wheels and the cam is coupled to the clevis. The clevis may be pivotally attached to the base member. The pivotal attachment allows the wheels to turn relative to the base member, allowing the portable basketball system to be steered around the playing surface. Furthermore, the adjustment member may be rigidly attached to the adjustable wheel assembly to control the pivoting of the clevis. 
     The adjustment member may be a lever having a handle position at one end to provide a gripping location while moving the portable basketball goals system. Alternatively, the adjustment member may be a foot pedal that transitions the adjustable wheel assembly from the unsupported position to the supported position. 
     The basketball goal system may also comprise a second set of wheels positioned at an opposing end of the base member. The second set of wheels may be fixed relative to the base member. The second set of wheels may further be in partial contact with the playing surface. As the adjustable wheel assembly transitions to the supported position, the elevation of the base member will cause the second set of wheels to also come in contact with the playing surface. 
     These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the manner in which the above recited and other advantages and objects of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
     FIG. 1 is a perspective view of a basketball goal system having a cut out section. 
     FIG. 2 is an exploded assembly view of an adjustable wheel assembly. 
     FIG. 3 is a cross-sectional view of an adjustable wheel assembly. 
     FIG. 4 is a cross-sectional view of an adjustable wheel assembly in another position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The presently preferred embodiments of the present invention will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the apparatus, system, and method of the present invention, as represented in FIGS. 1 through 4, is not intended to limit the scope of the invention, as claimed, but is merely representative of presently preferred embodiments of the invention. 
     Referring now to FIG. 1, a perspective view of a basketball goal system  100  is illustrated. The basketball goal system  100  is generally comprised of a base member  112 , a pole  116  or other supporting structure, and a basketball assembly goal  120 . To overcome the problems associated with previous basketball goal systems  100 , the present basketball goal system incorporates an adjustable wheel assembly  124 . 
     The adjustable wheel assembly  124  provides a mechanism whereby the base member  112  may be raised up and down in the vertical direction  4  to enable transport of the system  100 . The base member  112  has a lowered position and an elevated position. In the lowered position, the base member  112  is substantially in contact with the playing surface  128 . The playing surface  128  may be a basketball court made of any number of materials, such as wood, cement, asphalt, etc. Furthermore, the playing surface  128  may also include surfaces adjacent to the surface on which the game is played, such as grass or dirt. 
     The wheel assembly  124  provides a mechanism for transitioning the base member  112  from the lowered position to the elevated position. The wheel assembly  124  may comprise one or more wheels  132  that are selectively in contact with the playing surface  128 . The transition of the wheel assembly  124  from the lowered position to the elevated position may be operated by a lever  136 . The lever  136  may provide a method of using mechanical advantage from the length of the lever  136  to pivot about the wheels  132 . 
     The operation of lever  136  may be further assisted by the presence of a handle  140  disposed at the end of the lever  136  opposite the wheel assembly  124 . The handle  140  may provide a convenient location for grasping the lever  136  and controlling the movement of the basketball goal system  100 . 
     Once the base member  112  is in the elevated position, the lever  136  may be used to pull or push the basketball goal system  100  to a desired location or orientation. It may be preferred for the lever  136  to be a relatively strong rigid member, sufficient to maintain large tensile and compressive forces. This increased strength requirement is important where the lever  136  and the handle  140  are used to drive and pull the basketball goal assembly  100 . 
     The movement of the basketball goal system  100 , may require the lever  136  to be pushed in order to drive the basketball goal system  100 . In some situations in which the lever  136  is used to push the base member  112 , the handle  140  may provide a convenient and ergonomic location from which the user may apply the pushing force. Additionally, the handle  140  may provide a member that is easy to grab while pulling on the lever  136  to move the basketball goal system  100 . 
     The base member  112  may also comprise a second set of wheels  144 , as can be seen in the cut out section of FIG.  1 . The second set of wheels  144  may or may not be adjustable relative to the playing surface  128 . In one application, it may be preferable for the second set of wheels  144  to maintain contact with the playing surface  128 , even when in the lowered position. However, while in the lowered position a substantial portion of the base member  112  will be resting on the playing surface  128 , despite the presence of the second set of wheels  144 . Such an application may be preferred because of the increased cost associated with a second adjustable wheel assembly. However, if desired, the second set of wheels  144  may be adjustable. 
     Alternatively, the second set of wheels  144  may not be in contact with the playing surface  128  when the base member  112  is in the lowered position and the adjustable wheel assembly  124  is in the unsupported position. Rather, the second set of wheels  144  will come into contact with the playing surface  128  as the adjustable wheel assembly  124  transitions from the unsupported position to the supported position. 
     The second set of wheels  144  cooperate with the wheels  132  of the adjustable wheel assembly  124  to elevate a portion of the base member  112  above the playing surface  128 . Once the base member  112  is elevated on the wheels  132 ,  144 , the player may move or orient the basketball goal system  100  to the desired location and orientation. To assist in controlling the movement of the base member  112 , the adjustable wheel assembly  124  may be pivotally attached to the base member  112 . 
     The pivotal attachment to the base member  112  provides the basketball goal system  100  with steering capabilities. By having a rigid attachment of the lever  136  at the front of the base member  112 , the adjustable wheel assembly  124   112  can be turned to guide the base member  112  in a fashion similar to pulling a wagon. The range of the pivotal motion will depend upon the structure and position of the adjustable wheel assembly  124  in relation to the base member  112 . In one application, the adjustable wheel assembly  124  may have pivoting range up to about 90°. Other applications of the adjustable wheel assembly  124  may have pivoting range greater than about 90°. In yet another application, the pivoting range may be up to about 165°. Other ranges greater than 165° may be possible by controlling the structure of the base member  112 . 
     Referring now to FIG. 2, an exploded assembly view of an implementation of the adjustable wheel assembly  124  is illustrated. The adjustment of the wheels  132  of the adjustable wheel assembly  124  may be accomplished through one or more cams  150 ,  152 . A first cam  150  and a second cam  152  may be pivotally mounted on the axle  156  of the wheels  132 . In order to receive the axle  156 , the first and second cams  150 ,  152  may have a pivoting hole  160 . The pivoting holes  160  provide a location from which the cams  150 ,  152  may pivot relative to the wheels  132 . 
     The cams  150 ,  152  and the wheels  132  may be situated within a clevis  164 . The clevis  164  is a mounting structure configured to maintain an axle  156  and is often “U” shaped. The clevis has a plurality of slots  168  for receiving the axle  156 , while the axle  156  is maintaining the wheels and the cams  150 ,  152 . The slots  168  allow the axle  156  to be rotatably and slidably coupled to the clevis  164 . The purpose for this slideable attachment of the axle  156  in the clevis  164  will become evident in the discussion of subsequent figures. 
     In one assembled embodiment, the first cam  150  and the second cam  152  are positioned within the clevis  164 . The axle  156  is then placed through the slots  168  as well as through the pivoting holes  160 . Once the cams  150 ,  152  are positioned within the clevis  164 , the wheels  132  may be attached to the axle  156  on the outside of the clevis  164 . The first cam  150  may be spaced at a distance from the second cam  152  by a spacing member  172 . The spacing member  172  may simply be a rigid pin or other structure configured to hold the first cam  150  and the second cam  152  at a fixed distance. Multiple spacing members  172  may be used with the cams  150 ,  152  to reinforce the structure. Alternatively, the spacing member  172  may be a large solid member sandwiched between the cams  150 ,  152 . 
     In general, the spacing member  172  allows the first cam  150  and the second cam  152  to function as a single member. However, the two cams  150 ,  152  may be replaced by a single cam of a determined thickness. The single cam would be positioned and operated in much the same fashion as the two cam  150 ,  152  configuration. Conversely, more than two cams may be employed as well. 
     The structure of the cams  150 ,  152  may also be reinforced by attaching the lever  136  or other adjustment member. The attachment end  176  may be position between the drive arms  180  of the two cams  150 ,  152 . The width of the lever  136  would then provide a rigid spacing member to maintain the first cam  150  and the second cam  152  in a spaced relationship. The lever  136  may be attached to the cams  150 ,  152  through a number of fasteners  184  or other similar mechanisms. 
     While FIG. 2 illustrates one configuration of the adjustable wheel assembly  124 , it is only one exemplary embodiment. Multiple variations of the adjustable wheel assembly  124  may be possible by varying one or more of the components. For example, the clevis  164  is simply one method of retaining the cams  150 ,  152  and the wheels  132 . Structures performing the same function as the clevis  164  may be incorporated into the base member  112  as structural components of the based member  112 , but not a separate mechanism. 
     Similarly, the adjustable wheel assembly  124  may include varying number of cams  150 ,  152 . For example, a single cam  150  may be used in place of the first cam  150  and the second cam  152  or alternatively additional cams may be used with the first and second cams  150 ,  152 . The cams  150 ,  152  may be various materials, including plastic or metal. Furthermore, the shape of the cams  150 ,  152  may vary depending upon the geometry of the clevis  164  and base member  112  as well as the desired operation of the cam  150 ,  152 . 
     Referring now to FIG. 3, a cross-sectional view of the base member  112  and the adjustable wheel assembly  124  is illustrated. Portions of the pole  116 , the lever  136 , and the base member  112 , where the base member is in the lowered position, are illustrated. In the lowered position, the base member  112  is in direct contact with the playing surface  128  or similar adjacent surfaces. When the base member  112  is in the lowered position, the wheel assembly  124  is in an unsupported position. In the unsupported position, the wheels  132  of the wheel assembly  124  may or may not be in contact with the playing surface  128 . 
     While the wheels  132  may be in contact with the playing surface  128  when the base member  112  is in the lowered position, the wheels  132  and the wheel assembly  124  are not supporting the base member  112 . In the lowered position, the frictional contact between the base member  112  and the playing surface  128  will maintain the basketball goal system  100  in a determined location. Thus, in some configurations the wheels  132  may be resting on the playing surface  128  but not in a supported position. 
     In the embodiment illustrated, the lever  136  is in a substantially vertical  4  position. The vertical  4  position of the lever  136  corresponds to the lowered position of the base member  112  and the unsupported position of the wheel assembly  124 . However, the lever  136  may be positioned to correspond to any number of positions of the cam  152  and the base member  112 . The position of the lever  136  may correspond to the configuration and various embodiments of the adjustable wheel assembly  124 . 
     A function of the lever  136  in the present embodiment is to provide an actuation force or driving force for the cam  152 . The lever  136  may be attached to the drive arm  180  of the cam. In the cam  152  of FIG. 3, the drive arm  180  provides a location where the cam  152  may be rotated about the axle  156 . Thus, by applying a rotational force  184  to the lever  136 , the cam  152  may be made to rotate. 
     However, the drive arm  180  may be positioned in various locations on the cam  152 . For example, the drive arm  180  may not face the front of the basketball goal system  100 , as shown. In one implementation, the drive arm  180  may be positioned to face towards the rear of the basketball goal system  100 . 
     Alternatively, the drive arm  180  may not be the same layer of material as the other portions of the cam  152 . The cam  152 , as illustrated, is a single layer of material that may be cut out of a sheet of material having a desired thickness. However, the cam  152  may be made of several layers of material or of a three dimensional structure depending upon the needs of the embodiment. Thus, the drive arm  180  may be part of a second layer that is attached to a first layer of the cam  152 . 
     Furthermore, a lever  136  may be attached to the cam  152  through various other mechanisms besides the drive arm  180 . For example, the cam  152  may be rotated by an adjustment member pivotably coupled to the cam  152 . The pivotal connection would be located at a distance offset from the axle  156 , such that a vertical  4  motion of the adjustment member would produce a tangential force on the cam  152 . A force on the cam  142  that is tangential to the axle  156  will produce a rotation in the cam  152 . Because the adjustment member would be pivotally attached to the cam  152 , the cam  152  could rotate relative to the adjustment member. 
     Additionally, the cam  152  could be rotated by fixedly coupling the cam  152  to the axle  156  and then applying rotational force to the axle  156 . The rotational force on the axle  156  may be induced by a motor, crank, gear mechanism, or other similar device attached to the axle  156 . Similarly, a lever  136  could be connected to the axle  156  whereby pivoting the lever  136  would rotate the axle  156 . A rotational mechanism attached to the axle  156  could be implemented without requiring the need to reposition or adjust the wheels  132 . The wheels  132  could be attached to the axle in a rotational fit where the diameter of the axle  156  is smaller than the corresponding holes in the wheels  132 . Thus, the wheels  132  may rotate independently of the axle  156 . 
     Alternatively, the cam  152  may not pivot on the same axle  156  as the wheels  132 . In some applications, the wheels  132  and the cam  152  may be connected by a common structure, such that the cam  152  and the wheels  132  may move relative to the base member  112 . For example, such a structure could be comprised of a clevis  164  having two axles, where the wheels  132  pivot on one axle and the cam  152  pivots on the other axle. However, providing the wheels  132  and the cam  152  with a common axle  156  can reduce the overall part count as well as the manufacturing costs of the basketball goal system  100 . 
     While the present disclosure and the associated examples have illustrated the cam  152  as being rotated by a lever  136 , other mechanisms may be employed to rotate the cam  152 . For example, the drive arm  180  could be attached to a foot pedal or similar device where a downward force on the pedal could cause the cam  152  to rotate. The rotational force of the foot pedal could be applied to the drive arm  180 , the axle  156 , a pivotal attachment on the cam  152 , or other mechanism. The foot pedal could be made to lock into two positions corresponding to the supported and unsupported positions. However, a lever  136  does provide a large degree of mechanical advantage with minimal structure. Also, a lever  136  provides a location where a user may control the basketball goal system  100  while pushing and pulling the system  100  to the desired location. 
     Numerous other methods of rotating a cam  152  may be employed in the adjustable wheel assembly  124 . Similarly, multiple mechanisms for controlling the rotation of the cam  152  may also be employed without departing from the scope of the invention. 
     Regardless of the mechanism employed, the operation of the cam  152  will transition the base member  112  from the lowered position to the elevated position. Referring now to FIG. 4, the cross-sectional view of the adjustable wheel assembly  124  is illustrated in the supported position. The supported position of the wheel assembly  124  is achieved by rotating the cam  152  about the axle  156 . 
     The cam  152  elevates the base member  112  through the use of its geometric shape, having points at varying distances from the axle  156 . In general, a cam  152  is a structure having edges that are at varying distances from a central, pivotal location. The edges at the varying locations drive a follower that is displaced according to the shape of the cam. 
     The cam  152  employed in the present adjustable wheel assembly  124  similarly employs a perimeter or edge that has different distances from the axle  156 . To illustrate the function of the cam  152 , two radiuses referenced from the axle  156  are provided, a first radius  188  and a second radius  190 , as shown in FIG.  4 . 
     The first radius  188  is the point on the cam  152  that is in contact with a surface  194  of the clevis  164  when the base member  112  is in the lowered position. In the present embodiment, the surface  194  of the clevis  164  functions as a follower for the cam  152 . A follower can be described as a mechanism that responds to the rotation of a cam  152 , such that the varying geometries of the cam  152  drive the follower. 
     While the follower in FIG. 4 is the surface  194  of the clevis  164 , other members and devices may also function as a follower. For example, the cam  152  may be in direct contact with a portion of the base member  112 , driving the base member vertically  4  as the cam  152  rotates. Alternatively, the follower may be a point or small structure on the clevis  164  or base member  112 . The point or small structure would then be aligned to the cam  152 , such that the geometry of the cam  152  would drive the follower. Furthermore, the follower may be a rigid structure that extends laterally  6  into contact with the cam  152 . 
     Regardless of the type of follower used, the base member  112  will respond to the rotational motion of the cam  152  by traveling in a vertical  4  direction. In order for the base member  112  to obtain a vertical  4  motion relative to the wheels  132 , the wheels  132  must be capable of sliding relative to the base member  112 . In order to allow the wheels  132  to slide relative to the base member  112 , the wheels  132  are slidably coupled to the clevis  164 . The slidable attachment is achieved through slots  168  (shown in FIG. 2) in the clevis  164 . The slots  168  allow the axle  156  to not only rotate within the slot  168 , but also allows the axle  158  to slide vertically  4  relative to the clevis  164  and the base member  112 . 
     The length of the slots  168  will depend upon the amount of travel required to elevate the base member  112 . The distance that the base member  112  will be elevated above the playing surface  128  is the function of the difference between the lengths of the first radius  188  and the second radius  190 . The elevated distance  198  in illustrated in FIG. 4 as the distance between the playing surface  128  and the base member  112 . 
     In the embodiment illustrated in FIG. 4, the first radius  188  corresponds to the base member  112  being in the lowered position and the adjustable wheel assembly  124  being in the unsupported position. The second radius  190  corresponds to the base member  112  being in the elevated position and the adjustable wheel assembly  124  being in the supported position. The difference between the two radiuses  188 ,  190  is equal to the distance that the base member  112  is elevated above the ground  198 . 
     Because the second radius  190  is longer than the first radius  188 , the rotating cam  152  will elevate the base member  112  as the edges of the cam  152  slide along the surface  194  of the clevis  164 . The first radius  188  and the second radius  190  establish the distance between the axle  156 , on which the cam  152  pivots, and the surface  194  of the clevis  164 . Thus, as the base member  112  and the clevis  164  are displaced further from the axle  156 , the base member will elevate above the playing surface  128 . 
     Because the shape of the cam  152  will control the movement of the base member  112  relative to the wheels  132 , the shape of the cam  152  can be varied to provide a wide range of movement. For example, the length difference between the first radius  188  and the second radius  190  may be increased or decreased to change the lifting characteristics of the base member  112 . If the difference between the two radiuses  188 ,  190  is increased then the base member  112  will elevate higher off of the playing surface  128 . Conversely, if the difference between the two radiuses  188 ,  190  is decreased the elevation  198  will be smaller. 
     Additionally, the rate of change between the radiuses  188 ,  190  will control the responsiveness of the base member  112  to the cam  152  and the lever  136 . For example, if the rate of change between the radiuses  188 ,  190  is increased, then a small movement of the lever  136  will raise the base member  112  substantially. Conversely, if the rate of change between the radiuses  188 ,  190  is decreased, then a large movement of a lever  136  will be required to elevate the base member  112 . 
     Furthermore, the cam  152  may have a plurality of stable locations, such that an increase of force is required to rotate the cam in either direction. The stable locations may be produced by various geometries of the cam  136 . For example, the cam  152  may have various flat locations which will align with the surface  194  of the clevis  164 . The flat locations will have a locking-type effect on the lever  136 . As the flat location aligns with the surface  194  of the clevis  164 , the lever  136  will have an increased resistance to rotation in either direction from the flat location alignment. 
     Thus, flat locations may be placed in the cam  152  corresponding to the lowered position and the elevated position, such that the level  136  locks to the two positions. A variation of the flat location embodiment may be accomplished by replacing the flat location with a notch and protrusion, where the protrusion locks into the notch at determine orientations. 
     The cam  152  may also incorporate a stop to limit the travel of the cam  152  to a determine range. A stop may be implemented to prevent the lever from striking the pole  116  when lowering the base member  112 . Additionally, a stop may be implemented to prevent the cam  152  from striking the playing surface  128  when the base member  112  is in the elevated position and when the system  100  is being moved. The stops may be a protrusion on the cam  152  that butt against an interference structure in the clevis  164  or on the base member  112 . As a stop contacts an interference structure, the cam  152  and the lever  136  can no longer rotate. Thus, stops may control the motion of the lever  136 . 
     While the cam  152  may have many geometries and features, generally the cam  152  is a mechanism that is pivotally attached to the axle  156  of the wheel  132 . The cam  152  is operable by a lever  136  attached to the cam  152 . As the cam  152  rotates, the varying radiuses  188 ,  190  will vertically  4  displace the clevis  164  or the base member  112 . The vertical  4  displacement of the base member  112  will bring the wheels  132  into supported contact with the playing surface  128 . The basketball goal system  100  may then be transported to the desired location on the playing surface  128 . 
     The present invention may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.