Abstract:
A basketball goal includes an upright member and a backboard assembly and connecting members for mounting the backboard assembly to the upright member. A pivoting member is used to pivot the backboard assembly to raise or lower the rim. Locking members are also provided to secure the backboard into position after pivoting.

Description:
BACKGROUND OF THE INVENTION 
     A. Field of Invention 
     This invention pertains to a goal useful in playing basketball, and more particularly to a goal having an adjustable height. 
     B. Description of the Prior Art 
     Because the game of basketball is very popular, many families, as well as various institutions or organizations catering to the needs of families, install basketball goals on their property. In regulation basketball the height of the basketball must be exactly 10 feet. However, for many children and even adults, this height is not convenient. Therefore, it has been recognized in the art that it would be advantageous to provide a basketball goal having a rim or backboard with an adjustable height. One such goal structure disclosed in U.S. Pat. No. 4,465,277 consists of a vertical member supporting a cantilevered boom with a backboard at one end. However, this structure is large, complicated and too expensive for the home market. 
     Another goal structure shown in U.S. Pat. No. 4,881,734 consists of a parallelogram disposed on the top of an upright and supporting a backboard and a rim. However, this structure has a number of disadvantages. It relies on a complicated latching mechanism which allows the rim to be set only at certain pre-selected heights. Moreover, the mechanism wears out due to friction and has to be serviced frequently, or even replaced. Due to its complexity, the latch cannot be replaced in the field and must be returned to a shop. In addition, a special tool must be used to engage and disengage the latch for height adjustment. 
     OBJECTIVES AND SUMMARY OF THE INVENTION 
     In view of the above-mentioned disadvantages of the prior art, it is an objective of the present invention to provide a basketball goal having a backboard with a height which is easily adjustable. 
     A further objective is to provide a goal having components which do not need replacement whereby the goal is maintenance free. 
     Yet another objective is to provide a goal which is relatively simple and inexpensive to manufacture. 
     Other objectives and advantages of the invention shall become apparent from the following description. Briefly, an adjustable goal constructed in accordance with this invention includes an upright member with an upper end, backboard means, including a backboard and a rim, and upper and lower members arranged to form, with said upright member and said backboard means, a pivotable parallelogram. The goal also includes pivoting means disposed between one of said upper and lower members and said upright member for pivoting said parallelogram thereby raising or lowering the backboard means. The goal further includes locking means for locking said backboard into position so that it remains stable during play. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a side elevational view of a basketball goal constructed in accordance with this invention; 
     FIG. 2 shows a top view of the goal of FIG. 1; and 
     FIG. 3 shows a partial front view thereof. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the Figures, a basketball goal 10 constructed in accordance with this invention includes an upright member 12. This member may have either a square or a round 10 cross section. The lower end of member 12 may be anchored into the ground, or may be mounted securely on a platform 14. Platform 14 has wheels 16 which permit the platform to be moved at will. Of course, during play the platform is firmly anchored by locking wheels 16, or by other similar means. 
     At the top, upright member 12 is formed with a vertical elongated slot 18 communicating with the side walls of the member 12 by pin holes 20, 22. Pin hole 20 holds a pin 20&#39; for rotatably mounting an outrigger 24 as shown. Outrigger 24 may have a square or round cross section. Similarly pin hole 22 is used to hold another pin 22&#39; for rotatably mounting a sleeve 26. This sleeve 26 is coupled to a second sleeve 28 by a threaded rod 30. Mounted on rod 30 there is a lock nut 32. 
     Goal 10 also includes a backboard assembly consisting of a backboard 34, a frame 36 disposed behind, and secured to the backboard, and a rim 38. A conventional net 40 hangs down from rim 38. Secured to frame 36 there is a bracket 42 in pivotal engagement with the distal end of sleeve 28. Below bracket 42 there is an adapter 44 for pivotally coupling the distal end of outrigger 24 to frame 36. The threaded bar 30 may be turned to adjust the distance between the two sleeves 26, 38 such that a parallelogram is defined by the sleeves, outrigger 24, the top portion of upright member 12, and frame 36. The position of the rod is secured by tightening lock nut 32 against sleeve 28. By pivoting the sides of this parallelogram, the height H of rim 38 may be adjusted by pivoting the parallelogram around pins 20&#39; and 22&#39;. Importantly, during this process the backboard 34 is maintained parallel to member 18 and therefore remains vertical. 
     Goal 10 also includes a vertical sleeve 46 slidably engaged by a threaded rod 48. A lower end of rod 48 is engaged by a pin 50 pivoting in a bracket 52. A lock nut 54 is mounted on rod 48. Bracket 52 is secured to upright member 12. Another bracket 56 also secured to upright 12 is used to hold a cylinder assembly including a cylinder 58. The top of the cylinder 58 is open to receive and engage telescopically a second cylinder 60. These two cylinders 58, 60 cooperate to form a spring chamber for a coil spring 62 to keep the two cylinders 58, 60 separated. A threaded rod 64 is secured to upper cylinder 60, and is disposed concentrically within the two cylinders. The rod, furthermore, protrudes through the bottom of cylinder 58. Lock nut 66 is mounted on rod 64 below cylinder 58 as shown. 
     Cylinder 60 is pivotally secured at the top to the top of sleeve 46 by a pin 68. A bracket 70 is mounted on outrigger 24 and is pivotally secured to the top of cylinder 60. 
     The goal 10 may be provided with a single cylinder assembly, or with two assemblies disposed in parallel as shown in FIG. 3, each having a lower cylinder 58, 58&#39;, an upper cylinder 60, 60&#39;, a threaded rod 64, 64&#39; and so on. Moreover, as shown in FIG. 3, backboard 34 may be either rectangular, or may have the shape indicated in dashed line as at 34&#39;. 
     The goal described above may be adjusted as follows. Normally the backboard assembly is locked into position by lock nuts 54 and 66. Lock nut 54 stops cylinder 60, and therefore the backboard assembly from moving downward. Lock nut 66 stops cylinder 60 from moving upward. This feature of the invention insures that the backboard remains stable even under extreme conditions, for example when a person performs a dunk shot. In order to move the backboard assembly up, lock nut 60 is turned clockwise (assuming that rod 64 is threaded in the normal direction). This action allows the threaded rod 64, and cylinder 60 to move upward. The upward movement of cylinder 60 forces the parallelogram to pivot clockwise (as viewed in FIG. 1) thereby raising the backboard assembly. The movement of the cylinder 60 upward also forces sleeve 46 to move upward, away from lock nut 54. When the desired position of the backboard assembly is reached, lock nut 54 is turned counter-clock wise to move up until it re-engages sleeve 46. Thus, the backboard is once again locked into its position. 
     To lower the backboard assembly, the sequence is reversed. The lock nut 54 is turned clockwise to move it downward along threaded rod 48. This allows the sleeve 46 to move downward pulling cylinder 60 with it, and forcing the parallelogram to pivot counter-clockwise. This pivoting action lowers the backboard assembly. 
     One skilled in the art will appreciate that the position of the backboard and rim is continuously adjustable to any desired height. 
     Preferably the spring 62 is selected so that its coupling moment exceeds the coupling moment of the weight of the backboard assembly, the sleeves 26, 46 and outrigger 24. Under these conditions, the backboard will move upward unassisted, however, an extra force must be applied to it by hand or other means to make it move downward. 
     Obviously numerous modifications may be made to this invention without departing from its scope as defined in the appended claims.