Abstract:
A vertically adjustable backboard support includes a fixed position structure to which a shiftable backboard structure is sliding attached for vertical adjustment between several selectable elevations. A torsion spring counterbalance apparatus on the fixed position structure facilitates manual shifting of the adjustable backboard structure to any of its vertically adjusted positions. A vertically disposed outer tube of the fixed position structure includes vertically spaced openings in one of its side walls for receiving a cam secured to a vertical operating rod rotatably mounted to the shiftable backboard structure for selecting and maintaining desired vertical positions of backboard adjustment.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Vertically adjustable basketball backboards facilitate use of a basketball court by different age groups. The support for the backboard and rim needs to be structurally sound because of the tendency of players to hang on the rim during a slam dunk. Slide mechanisms affording vertical adjustment of the backboard have been commonly used, some with screw drives to effect the desired adjustment. Screw drives require considerable torquing effort, require lubrication, tend to wear and need to be replaced when they become worn. The screw in such construction carries the full weight of the adjustable backboard and its attachments, thus accelerating wear. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0002]    The vertically adjustable backboard assembly herein disclosed includes a fixed position structure and a vertically adjustable backboard structure supported on the fixed position structure. The fixed position structure includes a centrally positioned vertical rectangular section outer tube with a pair of vertically spaced horizontal beams rigidly secured at their mid sections to the outer tube near its top and bottom. The laterally outer ends of the beams have slide blocks with cylindrical openings rigidly secured thereto. The vertically adjustable structure includes a backboard, a rim, a pair of laterally spaced vertical guide rails rigidly secured to the backside of the backboard and an inner tube with a rim mounting plate on its lower end secured to a lower central part of the backboard. A cam operating rod is supported in the inner tube and includes a cam secured to its upper end and a combined torque and vertical thrust transmitting coupler at its lower end in the form of an eye rigidly secured thereto. The outer tube includes a series of vertically spaced openings which are individually engageable by the cam, upon rotation of the cam rod, to establish the desired height of the backboard. The vertically adjustable backboard assembly of this invention uses a torsion spring counterbalancing apparatus to counterbalance the weight of the backboard and parts secured thereto. In a preferred embodiment, a force balancing condition occurs when the backboard is near its mid point of vertical adjustment. When vertically adjusting the backboard a person uses a pivot and linear thrust tool in the form of a push pull pole with a connecter on its upper end to hook the eye on the lower end of the cam operating rod. Rotation of the rod in one direction engages the cam on its upper end in an aligned notch or slot in the vertically extending outer support tube of the fixed position structure. Rotating the rod in the opposite direction disengages the cam from the notch. The person then adjusts the adjustable backboard structure to a new vertical position using the push pull pole by first physically moving the counterbalanced backboard structure upward or downward to a desired height and next by rotating the cam operating rod to engage the cam in the newly selected opening in the outer support tube. The stationary support structure includes the before mentioned outer vertical support tube, a pair of vertically spaced horizontal upper and lower support beams rigidly secured at their midsection to the upper and lower ends of the outer support tube, vertically aligned slides secured to opposite ends of the beams and a torsion spring apparatus supported on the upper support beam and the upper end of the outer support tube. A support bracket is rigidly fixed to the rear midsection of each of the beams, the support brackets being adapted for connection to a rigid stationary vertically extending support. The vertically shiftable backboard structure includes a pair of laterally spaced vertical rails slidingly received in the slides. Each of the rails is rigidly secured to the backboard by vertically spaced upper and lower connectors or brackets. The rim supporting inner tube is telescopically fitted in to the outer tube with the rim mounting plate on its lower end connected to the central lower rear of the backboard and to the rim. A pair of laterally spaced support cables extend downward from the torsion spring counterbalancing apparatus and connect, respectively, at laterally spaced points to the upper brackets used to secured the rails to the backboard. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    A preferred embodiment of the invention is illustrated in the drawings, in which: 
           [0004]      FIG. 1  is a front view of the adjustable backboard and support assembly installed on a rigid support; 
           [0005]      FIG. 2  is a top view of the structure shown in  FIG. 1 ; 
           [0006]      FIG. 3  is a perspective view of the adjustable backboard assembly shown in  FIG. 1  removed from the rigid support and with the backboard and rim also removed; 
           [0007]      FIG. 4  is a side view of the backboard and support assembly shown in  FIG. 1 ; 
           [0008]      FIG. 5  is an exploded perspective view of the fixed position structure of the adjustable backboard assembly together with an inner tube adapted for connection to a backboard and a rim; 
           [0009]      FIG. 6  is a front view of the inner tube; 
           [0010]      FIG. 7  is a rear view of the assembled inner and outer tubes; 
           [0011]      FIG. 8  is a side view of the tubes shown in  FIG. 7 ; 
           [0012]      FIG. 9  is a front view of the tubes shown in  FIGS. 7 and 8 ; 
           [0013]      FIG. 10  is a partially sectioned view of the inner tube, cam and cam operating rod; 
           [0014]      FIG. 11  is an enlarged section taken on line  13 - 13  in  FIG. 8 ; 
           [0015]      FIG. 12  is an enlarged bottom view of the assembled tubes shown in  FIG. 8 ; 
           [0016]      FIG. 13  is a partial rear view of the lower end of the inner tube showing the thrust end of a push pull tool poised for insertion into the eye of the cam rod; 
           [0017]      FIG. 14  is a side view of the push pull tool; 
           [0018]      FIG. 15  is an exploded view of the counterbalancing mechanism; 
           [0019]      FIG. 16  is a perspective view of the vertically adjustable backboard structure in its highest position of vertical adjustment and the backboard and rim shown in broken lines for illustration purposes; 
           [0020]      FIG. 17  is a view similar to  FIG. 16  showing the adjustable backboard structure in its middle position of vertical adjustment, and 
           [0021]      FIG. 18  is a view similar to  FIGS. 16 and 17  showing the backboard structure in its lowest position of vertical adjustment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    The drawings illustrate a support assembly for a vertically adjustable basketball backboard which includes a fixed position structure  21  adapted for attachment to a fixed support; which may, for instance, be a vertical metal tube extending downwardly from the ceiling trusses of a gymnasium facility, now shown. The fixed position structure  21  includes a pair of vertically spaced horizontal beams  22 ,  23  with semi-circular mounting brackets  24 ,  26  rigidly secured to the mid section of their respective rear sides. As illustrated, the fixed position structure  21  is rigidly secured to a downwardly extending six inch cylindrical pipe  30  by fasteners  27  securing semicircular retainers  28 ,  29  to the brackets  24 ,  26  thereby preventing relative movement between the support pipe  30  and the fixed position structure  21 . The fixed position structure  21  also includes a vertical support member in the shape of rectangular section outer tube  37  rigidly secured adjacent its upper and lower ends as by welding to the upper and lower horizontally beams  22 ,  23 , respectively. A first pair of slides  41 ,  42  are rigidly secured by fasteners  43  to first corresponded ends  46 ,  47 , respectively, of the beams  22 ,  23 , and a second pair of slides  51 ,  52  are rigidly secured to second corresponding ends  53 ,  54 , respectively, of the beams  22 ,  23 , by fasteners  43 . A torsion spring counterbalancing assembly  61  is securely mounted on the top of the upper beam  22  and the outer tube  37 . 
         [0023]    The vertically adjustable basketball backboard structure  71  includes a rectangular backboard  72 , a rim  73 , a pair of laterally spaced vertical cylindrical guide rails  76 ,  77  rigidly secured by brackets  78 ,  79 ,  81 ,  82  bolted to the rear of the backboard  72  near its four corners and an inner tube  91  which has a cylindrical interior surface  93  and a vertically disposed rim mounting plate  92  rigidly secured thereto adjacent to its lower end. As shown in  FIG. 3 , a pair of laterally extending horizontal struts  96 ,  97  have laterally inner ends secured to the rim mounting plate  92  and laterally outer ends rigidly secured, as by welding, to the brackets  79 ,  82  bolted to the backboard at its lower rear corners. The inner tube  91 , as shown in  FIGS. 6 ,  10  and  11 , has a rectangular position collar or guide  101  connected near its upper end by snap rings  102  engaging annular grooves in the outer surface of the inner tube  91 . The position collar  101  maintains the inner tube  91  in central alignment with the outer tube  37 . A cam rod  113  is rotatably mounted in the cylindrical interior  107  of the tube inner  91  and extends above the upper end of the tube  91 . A cam  116  is rigidly secured to, and extends radially from the upper end of rod  113 . The cam rod  113  has a combined torque and axial thrust transmitting coupler  117  with a horizontal opening in the shape of an eye, the coupler being formed by welding an eye bolt to the lower end of the rod  113 . A snap ring  94  mounted in an annular groove in the cam rod  113 , near its lower end serves as an axial thrust bearing preventing upward axial movement of the rod  113  relative to the inner tube  91 . A cam  116  rigidly secured to and extending radially from the upper end of the cam rod  113  prevents downward movement of the cam rod  113  relative to the inner tube  91 . The cam rod  113  is rotationally biased in relation to the inner tube  91  toward a slot engaging position, as shown in  FIG. 11 , by a coil spring  114  coiled about the upper end of the inner tube  91  with opposite ends inserted into openings in the cam  116  and the position collar  101 , respectfully. 
         [0024]    When the vertically adjustable backboard structure  71  is vertically positioned to horizontally align the cam  106  with a selected one of three vertically spaced horizontal slots or openings  121 ,  122 ,  123  in the rear wall  126  of the outer tube  37 , the cam rod  113  and its cam  116  may be rotated into the selected opening in the outer tube  37 , thereby vertically positioning the backboard  72  at a selected height. As shown in  FIG. 15 , the counterbalance mechanism  61  includes a housing having a support frame  131  and a cover  132 . The counterbalance mechanism  61  also includes a shaft  133  supported in aligned bearings  134 ,  135 ,  136 ,  137  mounted on vertical walls  138 ,  139 ,  140 ,  141 , respectively, of the support frame  131  and a coil spring  142  having one end secured to the wall  140  and its other end secured to the shaft  133  through a tensioner  151 . Cable drums  152 ,  153  nonrotatably secured to the shaft  133  have backboard support cables  143 ,  144  coiled thereon. As shown in  FIG. 3 , the lower ends of the cables  143 ,  144  are secured to the bracelets  78 ,  81  secured to the upper rear of the backboard  72  and apply equal counterbalancing force to the adjustable backboard support structure  71 . The counterbalancing force applied through the spring biased cables  143 ,  144  can be adjusted by the tensioner  15  so as to be sufficient to elevate and maintain the adjustable backboard support structure  71  at a midpoint position in its range of vertical adjustments. In the midpoint position, the cam  116  is aligned with and is insertable in the central opening  122  in the outer tube  37 . 
         [0025]    Rotation of the cam  116  and vertical adjustment of the backboard  72  is achieved by use of an elongated operating tool or pole  161 , shown in  FIGS. 13 and 14 , which has a spherical shaped hook  162  extending radially from its upper end. The hook  162  is sized to pass through the eye or opening of the eye shaped coupler  117 . As shown in  FIGS. 7 ,  8  and  11 , the cam  116  has been inserted into the opening  121 . The cam  116  is resiliently biased toward its locking or latching position shown in  FIG. 11  by the coil tension spring  114  interconnected between the cam  116  and the position collar  101 . Thus the cam  116  is prevented from drifting out of the engagement with a selected opening. Vertical adjustment of the counterbalanced backboard from its central balanced position to its top or bottom position is easily achieved by manually pushing or pulling on the pole  161  with the hook  162  engaged in the eye of the coupler  117 . 
         [0026]      FIG. 16  shows the backboard structure  71  adjusted to its highest position in which event the cam  116  engages the opening  121 .  FIG. 17  shows the backboard structure  71  adjusted to its intermediate position wherein the cam  116  engages the opening  122  and the  FIG. 18  shows the backboard structure  71  adjusted to its lowest position with the cam  116  engaging the opening  123  in the outer tube  37 . 
         [0027]    The herein illustrated and described adjustable backboard assembly utilizes torsion spring counterbalancing of the vertically adjustable backboard structure which permits direct manual force to be used to quickly and easily move the backboard between three different vertical positions. A drive mechanism is not needed to change the height of the backboard to facilitate use of the court by different groups of players, such as players of different age groups.