Breakaway basketball goal
BACKGROUND AND SUMMARY 
     The invention relates to a basketball goal assembly which will give or breakaway in response to a given threshold force on the rim such as a slam dunk. 
     A need has arisen for a breakaway basketball goal in order to protect the player by absorbing energy in order to reduce wrist, hand and arm injuries. There is a further need to protect the backboard to which the rim is mounted from breaking or shattering, especially in the case of fiberglass backboards. 
     In one type of known breakaway basketball goal, a pivot point is provided at the back edge of the rim assembly in the horizontal plane of the rim. A rocker arm assembly extends downwardly and rearwardly into a hydraulic cylinder or shock absorber at an angle which permits downward pivoting of the rim in response to a certain force collapsing or retracting the cylinder or shock absorber. 
     In another type of breakaway goal, a hinge point is provided with a fastener, and a sheer pin which breaks when the goal is overloaded, after which a new sheer pin is inserted in order to resume play. 
     The present invention provides a simple and effective breakaway basketball goal with releasable mounting structure. The rim is automatically returned, without manual intervention, upon removal of the overload force. User adjustable control means varies the threshold overload force for breakaway. A protective pinch gap shroud is provided covering a gap between mounting plates when the rim is released, to prevent a player from pinching his fingers in such gap. The shroud also extends between the mounting plate and the backboard to dampen oil canning. The mounting plate has a universal aperture mounting configuration. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a breakaway basketball goal assembly constructed in accordance with the invention. 
     FIG. 2 is a top view of a portion of the structure in FIG. 1. 
     FIG. 3 is a sectional view taken along line 3--3 of FIG. 2. 
     FIG. 4 is a view like FIG. 3 but showing the assembly in a released position. 
     FIG. 5 is a sectional view taken along line 5--5 of FIG. 3. 
    
    
     DETAILED DESCRIPTION 
     There is shown in FIG. 1 an automatic return slam dunk breakaway basketball goal assembly 2 for mounting to a backboard 4. The assembly includes a basketball goal rim 6 having a plurality of rams 8 for holding net 10. Mounting plate means 12, FIG. 3, is mounted to backboard 4 by a plurality of bolts such as 13-16, FIG. 5. Means 16 is provided for releasably mounting rim 6 to mounting plate 12 and releasing the rim for movement from a first to a second position to absorb force on the rim greater than a given threshold, and automatically returning the rim to the first position without manual intervention upon removal of the force. Resilient biasing means is provided by compression spring 18 biasing rim 6 to its first position. User adjustable control means is provided by nut 20 on threaded stud 22 for varying the bias of biasing means 18 for changing the noted given threshold force. 
     As seen in FIGS. 1, 3 and 4, means 16 pivotally mounts rim 6 to mounting plate 12. Rim 6 has a first horizontal position, as shown in solid line in FIG. 1, and has a second downwardly pivoted position, as shown in dashed line in FIG. 1 at arrow 24, responsive to a slam dunk or other overload downward force on the rim. Biasing means 18 biases rim 6 to the horizontal position and yields in response to the given threshold downward force on the rim to permit pivoting of the rim to the downward position. 
     Pivotal mounting means 16 includes a second mounting plate 26 rigidly mounted to rim 6 and pivotally mounted to first mounting plate 12. Second mounting plate 26 is an inverted generally L-shaped member having a horizontal leg 28 secured to rim 6 at weldment 30, and having a generally vertical leg 32 pivotally mounted at its lower end to the lower end of first vertical mounting plate 12 at pivot point 34. Biasing means 18 is operatively coupled to the first and second mounting plates 12 and 26 to bias such plates in a given direction relative to each other. 
     As seen in FIG. 4, second mounting plate 26 pivots rightwardly and downwardly away from mounting plate 12 at pivot point 34. Pivot point 34 is below the horizontal plane of rim 6. Spring 18 extends in a generally horizontal plane below the plane of rim 6 and above pivot point 34. The biasing means includes horizontal stud 22 having its left end formed with a T-shape or cross bar 36 retained on the left side of a rightwardly raised boss 37 formed in vertical mounting plate 12. Stud 22 extends righwardly from head 36 through an aperture 38 formed in raised boss 37. The stud is trapped in the raised boss but does have some free play therein to allow pivoting of stud 22 slightly downwardly as mounting plate 26 and rim 6 pivot downwardly. Besides passing through aperture 38 in raised boss 37, stud 22 also extends rightwardly through an aperture 40 in a rightwardly raised boss 41 of vertical leg 32 of mounting plate 26. Aperture 40 is wider, i.e, greater vertical extent as seen in FIG. 3, than aperture 38 to enable the noted up-down pivoting of stud 22 therein. Vertical slots, such as shown at 43 and 45, FIG. 5, are formed in the mounting plates to facilitate formation of bosses 37 and 41. 
     Compression spring 18 encircles stud 22. The left end of compression spring 18 bears against boss 41. The right end of stud 22 is threaded and receives nut 20 and retaining washer 42. The right end of compression spring 18 bears against washer 42. A plastic bellows 44 is provided around spring 18 between retainer 42 and vertical leg 32 to provide a flexible expansible cover for the spring and to protect the players. Pivoting of vertical leg 32 of support plate 26 away from vertical support plate 12 at pivot point 34 compresses spring 18 when the downward force on rim 6 is greater than a given threshold or overload. Turning nut 20 clockwise or inwardly compresses spring 18 and increases the amount of force on rim 6 necessary to cause release and breakaway for pivoting to the downward dashed line position in FIG. 1. Conversely, turning nut 20 outwardly or counterclockwise reduces the amount of threshold force necessary for release and breakaway. This mechanism thus provides user adjustable control means for varying the bias of spring 18 for changing the given threshold. 
     Rim 6 has a pair of supports 46 and 48, FIGS. 1 and 5, extending downwardly from opposite undersides of the rim, at weldments such as 50, and joined at a central portion 34 forming the noted pivot point adjacent backboard 4. Vertical mounting plate 12 includes means 52 engaging and pivotally mounting central portion 34 of the supports. Vertical leg 32 of second support plate 26 is rigidly secured to the central portion 34 of supports 46 and 48 at weldments 54 and 56. Portion 52 of vertical mounting plate 12 is curled around central portion 34 of the supports and coined to provide a snug interference type fit substantially eliminating vertical and horizontal free play at pivot point 34. Vertical leg 32 of the pivoted mounting plate extends downwardly and slightly rightwardly at 51 away from plate 12 and has a central aperture 53 therethrough, FIGS. 3 and 5. The portions 55 and 57 on opposite sides of central portion 51 and slot 53 of vertical leg 32 extend substantially straight downwardly behind, as viewed in FIG. 5, central portion 34 of supports 46 and 48, which is left of central portion 34 in FIG. 3, and are attached thereto at the noted weldments 54 and 56. Portion 52 of mounting plate 12 extends forwardly, FIG. 5, through aperture 53, which is rightwardly through aperture 53 in FIG. 3, and then curls around central portion 34 downwardly and rearwardly and again slightly upwardly at end segement 59 of curled portion 52. Aperture 53 continues downwardly through the bottom of vertical leg 32 to accommodate curled portion 52 therein. 
     A protective pinch gap plastic shroud 58 has a top portion 60 and side portions 62 and 64 covering the top and sides of the first and second mounting plates 12 and 26 and the gap 66 therebetween, FIG. 4, when mounting plate 26 is pivoted away from mounting plate 12, to prevent a player from pinching his fingers in such gap. Shroud 58 also includes a rear portion 68 extending vertically between backboard 4 and mounting plate 12 to dampen oil canning against the backboard and minimize the noise caused thereby. 
     Mounting plate 12 has a plurality of apertures therethrough, some of which such as 70 and 71, FIG. 5, have an extended slot configuration, and others such as 72 and 73 have an extended slot configuration oblique to the first extended slots and which also may be triangular, to provide a universal mounting aperture configuration to fit many different backboards. Mounting plate 26 has counterpart slots 74-77 of comparable shape to slots 70-73 but of larger cross section to accommodate the heads of bolts 13-16 therethrough when plate 26 is in its first position against plate 12. 
     It is recognized that various modifications and alternatives are possible within the scope of the appended claims.