Abstract:
A basketball goal support structure includes a support base and a pneumatic cylinder coupled to the support base. A pneumatically operated rod is extendably disposed insure the pneumatic cylinder. The rod is adapted to couple a basketball goal assembly to the end of the rod. The structure includes means for controllably applying pneumatic pressure to the interior of the cylinder to lift the rod out the cylinder, and means for self-propelling the base to a selected location.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Priority is claimed from U.S. Provisional Application No. 60/557,328 filed on Mar. 29, 2004. 

   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not applicable. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates generally to the field of sporting equipment. More specifically, the invention relates to portable support structures for basketball goals which have adjustable goal backing height. 
   2. Background Art 
   Basketball goal structures known in the art include various height adjusting mechanisms, and various devices to make the basketball goal portable. Representative prior art basketball goals are described below. 
   U.S. Pat. No. 6,554,243 issued to Davis et al. Discloses a rollable sports ballast base for supporting a sports apparatus support member. The ballast base includes a base member having a top and bottom surface. The bottom surface contacts a ground support surface such as a driveway or other playing surface. There is at least one wheel assembly, retractable from a lowered position to a raised position. The wheel assembly includes a pivoting connector coupled to the base member and a wheel bracket coupled to the pivoting connector. The wheel bracket includes an axle, at least one wheel, and a handle extending outwardly from the wheel bracket. The handle is used to pivotally rotate the wheel assembly about a transverse axis. When the handle is rotated away from the base member, the wheel assembly is placed in a lowered position whereby the wheel contacts the support surface, thus separating the bottom surface of the base member from the support surface. 
   U.S. Pat. No. 6,488,599 issued to Nye relates to quick-release locking mechanisms for adjustable basketball goal systems, and methods for using the same to adjust the height of a basketball goal above a playing surface. An adjustable basketball goal system may include basketball goal connected to a rigid support via a deformable goal support structure. A second arm may be coupled to the rigid support. A first arm may be coupled to the deformable goal support structure and may slidably engage the second arm. Locking plates may selectively bind the second arm with respect to the first arm to selectively lock relative motion of the arms. Locking relative motion is performed to maintain the basketball goal at a desired height. In an alternative embodiment, an engagement grip maybe attached to the first arm, and may contain multiple locking members configured to pivot to simultaneously engage openings formed in the second arm to prevent movement of a first arm relative to the second arm. In another alternative embodiment, an engagement grip may have only a single locking member configured to slide into one of a plurality of openings disposed along the length of the second arm. 
   U.S. Pat. No. 6,432,003 issued to van Nimwegen discloses a portable basketball goal system having an adjustable wheel assembly. The portable basketball goal system may comprise a rigid pole, a support base, an adjustable wheel assembly, and an engaging member. The support base is configured to maintain the rigid pole in a generally elevated position. The adjustable wheel assembly is connected to the support base and has an engaged and disengaged position. In the engaged position, the wheel assembly supportably engages a playing surface. In the disengaged position the wheel assembly does not supportably engage the playing surface. The adjustable wheel assembly may be slidably coupled to the support base. The adjustable wheel assembly may be operated by an engaging member coupled to a cam surface. The cam surface may interact with a follower to move the adjustable wheel assembly between the engages and disengaged positions. 
   U.S. Pat. No. 6,155,938 issued to Mower relates to a push button height adjustment mechanism for a basketball goal assembly. The mechanism is for adjusting the height of a basketball goal above a playing surface. The basketball goal assembly includes a deformable goal support structure interposed between a rigid support member and a basketball goal. A first end of an extension arm pivotally connects to an extension that protrudes from the back side of the goal support structure. A second end of the extension arm is pivotally connected to the support member. An adjustment mechanism disposed in relation to the extension arm allows the length of the extension arm to be adjusted. The adjustment of the length of the extension arm selectively deforms the goal support structure, thereby adjusting the height of the basketball goal in relation to the playing surface. A counterbalance member is operably disposed in relation to the goal support structure to facilitate counterbalancing between the weight of the basketball goal and a tensile force applied to the extension arm. The adjustment mechanism may comprise a spring-biased push button mechanism. With the use of the spring-biased push button mechanism, a user is capable of adjusting the height of the basketball goal in relation to the playing surface using only a single hand. 
   U.S. Pat. No. 5,879,247 issued to Winter et al. discloses an adjustable basketball goal system for adjusting the height of a basketball goal above a playing surface. The basketball goal includes a deformable parallelogram structure attached at one end to a rigid support. A basketball goal is attached to the other end of the parallelogram structure. An adjustment lever is pivotally mounted to the rigid support below the parallelogram structure. An extension arm is positioned between the parallelogram structure and the adjustment lever such that movement of the adjustment lever deforms the parallelogram structure which repositions the basketball goal to a different height above the playing surface. A lockable piston assembly is attached to the rigid support and to the adjustment lever. The piston assembly includes a switch which locks the piston assembly preventing the parallelogram structure from deforming. An actuation trigger pivotally connected to the adjustment lever can be engaged to move the switch to an unlocked position thereby allowing the height of the basketball goal to be adjusted. The piston assembly also serves to counterbalance the weight of the basketball goal such that the height of the basketball goal can be adjusted with minimal force. 
   U.S. Pat. No. 5,919,102 issued to Smith et al. discloses a mobile or permanently fixed basketball goal system. In the system disclosed in the Smith et al. &#39;102 patent, the backboard and hoop can be adjusted to a desired height by a user. The goal system has a vertical support member having a base end, a backboard end and an intermediate portion, and a backboard including a hoop. Crossmembers pivotally connect the backboard to the vertical support member on one side of the backboard end, to form an adjustable parallelogram. At least one of the crossmembers extends beyond the vertical support member to an extension end. A clamp is mounted on a brace for the vertical support member or directly on the vertical support member. The clamp is fixedly adjustable within a continuous range and connects with the counterbalanced extension end via an extension member. When the clamp is moved, it acts to rotate the extending crossmember to raise or lower the backboard and hoop. 
   SUMMARY OF THE INVENTION 
   One aspect of the invention is a basketball goal support structure. A support structure according to this aspect of the invention includes a support base and a pneumatic cylinder coupled to the support base. A pneumatically operated rod is extendably disposed insure the pneumatic cylinder. The rod is adapted to couple a basketball goal assembly to the end of the rod. The structure includes means for controllably applying pneumatic pressure to the interior of the cylinder to lift the rod out the cylinder, and means for self-propelling the base to a selected location. 
   Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows one embodiment of a basketball goal structure according to the invention. 
       FIG. 2  shows a cross section of an upper portion of a pneumatic cylinder used to adjust the goal height. 
       FIG. 3  shows an external drip port for the upper cylinder section of  FIG. 2 . 
       FIG. 3A  shows a spill port cover in greater detail. 
       FIG. 4  shows one example of a self-propulsion device with retractable wheels. 
       FIG. 5  shows a stake retainer used to hold balance stakes to retain the goal base. 
       FIG. 5A  shows a detail of a stake retainer. 
       FIG. 5B  shows another detail of a stake retainer. 
   

   DETAILED DESCRIPTION 
   An embodiment of a pneumatically height-adjustable, self propelled basketball goal support structure is shown in cutaway view in  FIG. 1 . A goal support base  10  may be made from heavy-gauge sheet metal, such as from carbon steel or stainless steel. Heavy gauge sheet metal is preferred to provide suitable weight, so as to reduce the possibility of tipping the goal support structure during use. Preferred dimensions for the base are about 4 feet in length, about 3½ feet in width and about 1 foot height. A pneumatic cylinder  12  is affixed to the base  10 . The pneumatic cylinder  12  may be supported laterally by braces  12 A, which may be welded or otherwise affixed to the base  10 . Materials from which the base  10 , cylinder  12  and braces  12 A are made is a matter of discretion, however considerations of strength, resistance to corrosion, ability to withstand internal pressures inside the cylinder  12 , and mass are desirable when selecting such materials. As will be readily appreciated, using dense, high strength materials such as steel will provide the goal support structure with suitable mass to prevent undue movement during play. 
   A pneumatic piston  42  and rod assembly  14  are disposed inside the pneumatic cylinder  12 . As will be further explained with reference to  FIG. 2 , the rod  14  and piston are suitably sealed with respect to the interior of the cylinder  12  such that application of pneumatic pressure to the lower portion of the cylinder  12  will cause the piston  42  and the rod  14  to move upwardly, out of the cylinder  12 . In  FIG. 1 , the rod  14  is shown as being made from a single tubular element and having essentially a right-angle bend in its upper portion, such that a goal support plate  18  may be affixed at an end of the rod  14 . However other suitable structures for forming the rod  14  to as to both lift vertically out of the cylinder  12  and include provision for affixing the support plate  18  will occur to those of ordinary skill in the art. The configuration shown in  FIG. 1  is intended to place the goal support plate  18  in a position extended outwardly from the base  10  to avoid interference during play. 
   The support plate  18  may be suitably configured to affix thereto a conventional basketball goal backboard, hoop and net assembly (not shown). The rod  14 , as shown in  FIG. 1 , or alternatively the cylinder  12  itself, may include a pressure relief valve  16  set at a suitable safe pressure such that seal bursting is avoided and that excessive lifting pressure is not applied to the piston  42  and rod  14 . The relief pressure which actuates the relief valve  16  can also be selected to lower any person(s) hanging on the rim of the goal for an extended period. 
   Propulsion of the base  10  from one location to another may be performed by a self propulsion system  51  having retractable wheels  38 . The self propulsion system  51  will be explained with reference to  FIG. 4 . The purpose of including retractable wheels is to provide the base  10  with additional stability against tipping when the goal support is in use. 
   The goal support structure may include a manual or foot-operated air pump (not shown). The present embodiment includes a battery  20  or similar electric power storage for remotely operating an air compressor  24 . The compressor  24  may be a conventional rotary, positive displacement pump driven by an electric motor  24 A, or may be a foot or hand operated pump as previously explained. The compressor  24  provides pneumatic pressure to raise the rod  14  as needed, and may also be used to provide air pressure such as for inflating basketballs or inflatable toys. The motor  24 A may be controlled by a controller  22 . The controller  22  may include a microprocessor, and typically includes any well known type of motor control to operate the motor  24 A as needed. The controller  22  may be operated by a foot switch  32  disposed on the base  10 , thereby operating the compressor  24  to raise the rod  14 , or the controller  22  may in addition, be operated by a remote control  44 . The remote control  44  may be hard-wired to the controller or may use any well known control link such as infrared or radio telemetry. The controller  22  may also be configured to operate the self propulsion system  51  (see  FIG. 4 ). The motor  24 A may in some embodiments drive the self-propulsion system  51  under control of the controller  22 . In other embodiments, the self propulsion system  51  may include a separate motor. In some embodiments, the controller  22  may include suitable circuits (not shown separately) for conditioning ordinary house current to charge the battery  20  and/or to operate the motor  24 A. House current may be supplied through a suitable cord and plug assembly  26 . 
   When actuated, the compressor  24  pumps air into the lower end of the cylinder  12 . A check valve  30  may be included in the pneumatic connection between the compressor  24  output and the lower part of the cylinder  12  such that air pressure is maintained therein after the compressor  24  is stopped. The compressor  24  output may also be coupled to a utility port  28 . The utility port  28  may be used for general compressed air purposes, as explained above, including ball and toy inflation. Pressure within the cylinder  12  may be monitored by a pressure gauge  36 . If, during use the pneumatic pressure drops such that the rod  14  may drop into the cylinder  12 , the compressor  24  may be actuated so as to restore the pressure to a suitable level. If the pressure drop has occurred because a person was hanging on the goal, actuating the compressor should only be performed when the person stops hanging on the goal and the relief valve has stopped discharging. 
   The present embodiment of the base  10  includes provision for retaining balancing stakes  40  at the end of the base  10  opposite to the location of the cylinder  12  and rod  14 . The stakes  40  which may be hammered into suitable ground surface, for maintaining balance and stability of the goal support structure during play. 
   In use, the goal support structure may be moved to a selected location for play by actuating the self propulsion unit  51  (see  FIG. 4 ), which includes lowering the wheels  38  to their movement position and driving the goal support structure to the selected location. At the selected location, the wheels  38  may be retracted, such that the base  10  rests entirely on the ground surface. In suitable ground surface conditions, the balancing stakes  40  may be hammered into the ground to further support the goal support structure. The compressor  24  may then be actuated by operating the foot switch  32  to the “up” position, which closes an electrical switch  32 B such that the compressor  24  is actuated. Operating the compressor  24  continues until the rod  14  is raised such that the goal support  18  is moved to a desired height. Measurements of selected heights, such as 4, 6, 8, 10 and 12 feet should be clearly scribed on the rod  14  to enable the user to set the goal at a known, selected height. If too much height is attained, or at the time the goal is desired to be lowered, the foot switch  32  may be operated in the “down” position, so as to operate a valve  32 A to release pressure from inside the cylinder  12 . Alternatively, the compressor  24  may be operated by the remote control  44 . Similarly, the valve  32 A may include a suitable electrical actuation device (not shown) such that the remote control  44  may be used to raise and lower the rod  14 . The arrangement of pneumatic and electrical connections in  FIG. 1  is provided to illustrate the principle by which the goal support structure of the invention operates, and is not strictly intended to limit the scope of the invention. 
   The upper portion of the cylinder  12 , including detail of the piston  42  and rod  14  are shown in  FIG. 2 . The cylinder  12  includes on its interior wall, at a suitable position near the longitudinal end, a stop or limit  21 , which prevents the piston  42  from moving beyond a selected position. The rod  14  may be sealed to the inner surface of the cylinder  12  by o-rings  19  or the like. Similar sealing may be included on the exterior surface of the piston  42 . A generally conically shaped weather seal  15  may be included on the top of the cylinder  12  and seal against the outside of the rod  14 , to deflect rain and water from entering the interior of the cylinder  12 . A secondary weather seal  13  may be included below the weather seal  15  and above the limit  21 . A spill port  17  may be located above the secondary seal  13  to enable and moisture that does bypass the weather seal  15  to exit the cylinder  12  and thus reduce the chance of harming the components inside the cylinder. 
     FIG. 3  shows a preferred position of the spill port  17 .  FIG. 3A  shows one embodiment of the spill port  17  as including a rounded-head cap  23 , a weather seal  25 , and a drip hole  27 . The embodiment of  FIG. 3A  is designed to avoid creating a safety hazard where at the spill port  17 , to generally exclude rain water from entering the spill port  17 , and enabling relatively free discharge of water from the spill port  17 . 
     FIG. 4  shows an embodiment of self-propulsion system and retraction system for one of the wheels  38 . The wheel  38  is fixedly supported on a drive shaft  38 A. The drive shaft  38 A is rotatably supported by a bearing  49 B disposed in the end a pneumatic lift rod  41 , and by another bearing  49 A disposed in a lateral actuation linkage  49 . 
   The pneumatic lift rod  41  is disposed in a lift cylinder  39 . The lift cylinder  39  may be pneumatically coupled (with suitable controlled valves) to the compressor ( 24  in  FIG. 1 ) such that actuation of the compressor pressurizes the upper part of the lift cylinder  39 , thus extending the lift rod  41  from the cylinder  39 . This has the effect of lowering the wheel  38  to the ground. After the wheel  38  reaches the ground, continuing to extend the lift rod  41  has the effect of raising the base  10  from the ground to enable free movement. The lift system can also aid in the removal of the balancing stakes  40  from their anchored position, by lifting the base  10  from the ground. Lifting the base  10  from the ground will pull the balancing stakes  40  at least partially out of the ground. 
   The lateral actuation linkage  49  may be used to laterally extend and retract the drive shaft  38 A and the wheel  38  from the base  10 . In the retracted position, the drive shaft  38 A is free to rotate, and thus the wheel  38  may freely rotate as well. In such position, the base  10  may be moved manually, if desired. If the linkage  49  is operated to extend the wheel  38  laterally outward from the base  10 , a driven gear  43  on the end of the drive shaft  38 A engages with a drive gear  45  disposed on the end of a motor drive shaft  47 . A drive unit  51  may include a motor (not shown separately) for rotating the motor drive shaft  47 , typically when so operated by the controller ( 22  in  FIG. 1 ), and for operating the lateral linkage  49 , such as by a worm and sector assembly (not shown separately) coupled to a suitable motor (not shown separately). In some embodiments, the lateral linkage  49  may be omitted entirely. In some embodiments, the lift cylinder  39  and lift rod  41  may be substituted by, for example, a worm and sector operated by a suitable motor, or by a hand crank. The foregoing examples are meant to illustrate the principle, and are not strictly intended to limit the scope of the invention. In some embodiments, only two of the four wheels  38  are coupled to the self propulsion system, and the other two wheels  38  may be 360 degree rotatable casters, such that under self propulsion, the goal support system may be easily steered by the used to the selected location. A manual version of the wheel assembly may be installed where the goal is moved by a stirring rod. 
     FIG. 5  shows the back end of the base  10  in detail to illustrate a convenient means for storing the balancing stakes  40  on the back of the base  10 . The stakes  40  may be held in place by storage retaining clips  51  formed into or otherwise affixed to the back of the base.  FIG. 5A  shows one of the storage clips  51  in detail.  FIG. 5B  shows a balance retaining clip  55  affixed to the back of the base  10 . The stake  40  is inserted through the balancing clip  55  and is driven into the ground  57  to provide balancing support for the base  10  when the goal assembly (not shown) is affixed to the goal support ( 18  in  FIG. 1 ). 
   While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.