Patent Publication Number: US-2015059276-A1

Title: Shock absorber for sports floor

Description:
BACKGROUND 
     1. Field of the Inventive Concepts 
     The inventive concepts disclosed herein relate generally to a shock absorber, and more particularly, but not by way of limitation, to a shock absorber for a sports floor. 
     2. Brief Description of the Related Art 
     It is known to provide cushioning pads under a sports flooring system to provide resiliency to the floor. In such systems, the amount of cushioning provided by the pads is generally controlled by the hardness of the pads. Advantages and disadvantages exist to using either hard or soft pads. 
     Specifically, in sports such as basketball and racquetball, it is important that the floor be relatively stiff so that the ball bounces easily and uniformly throughout the floor. High durometer (hard) resilient pads produce a floor having preferred ball response characteristics. However, hard pads provide little shock absorption and have a greater potential to cause injury to the athlete. This problem is especially severe when heavy loading occurs from a number of athletes performing in close proximity to each other. 
     Low durometer (soft) resilient pads provide greater shock absorption and hence provide a higher level of safety or protection to the athlete. However, floors employing soft pads do not produce desirable ball response characteristics under normal loading conditions, and thus are not suitable for sports such as basketball and racquetball. Furthermore, soft pads are prone to “compression set” which is a permanent change in profile after the pad has been subjected to high loads for an extended period of time. Such compression set can occur in areas where bleachers, basketball standards, or other gymnasium equipment are likely to be placed for periods of time. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is an exploded, perspective view of a sports floor utilizing a shock absorber constructed in accordance with the inventive concepts disclosed herein. 
         FIG. 2  is a perspective view of the shock absorber of  FIG. 1 . 
         FIG. 3  is a cross-section taken along line  3 - 3  of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present). 
     In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the inventive concept. This description should be read to include one or more and the singular also includes the plural unless it is obvious that it is meant otherwise. 
     Further, use of the term “plurality” is meant to convey “more than one” unless expressly stated to the contrary. 
     Finally, as used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
     Referring now to the drawings, and more particularly to  FIG. 1 , a floor assembly  10  having a floor surface  11  made out of a plurality of strips of material, such as strips of wood  12 , is illustrated. The floor assembly  10  illustrated is the type that would be suitable for playing basketball or other sports. The strips of material are typically manufactured from maple or other suitable wood, but could be manufactured from other suitable materials. Resting directly under and in contact with the underside of the floor surface  11  is a sub-flooring  14 . The sub-flooring  14  supports the strips of wood  12 . The sub-flooring  14  typically includes a first layer of plywood  16  and a second layer of plywood  18 . The first layer of plywood  16  is often oriented in one direction while the second layer of plywood  18  is oriented in a second direction which is often 45° (not shown) or 90° ( FIG. 1 ) relative to the first direction. A cement slab is generally provided as a rigid support base  20  for the floor surface  11  and the sub-flooring  14 . 
     A plurality of shock absorbers  22  constructed in accordance with the inventive concepts disclosed herein are illustrated supporting the sub-flooring  14  in a spaced apart relation with respect to the support base  20 . The shock absorbers  22  are connected to the bottom surface of the first layer of plywood  16  at a substantially equal center-to-center distance. For a basketball court, the shock absorbers  22  are generally required to be spaced at 9 13/16 inch center-to-center intervals, by way of example. For a multi-purpose floor, the shock absorbers  22  would generally be required to be spaced at 12 inch center-to-center intervals to provide additional flex in the playing surface. In one embodiment, the shock absorbers  22  are aligned with one another and positioned with substantially the same orientation as one another. 
     Referring now to  FIGS. 2 and 3 , the shock absorber  22  has a base  24  and a plurality of teeth  26 . The base  24  has a substantially rectangular configuration with a first side  28  and an opposing second side  30 . In one embodiment, the width of the base  24  is about two inches and the length of the base  24  is about two and one half inches. The base  24  may be attached to the sub-flooring  14  with the second side  30  of the base  24  positioned adjacent to the sub-flooring  14 . The base  24  may be connectable to the sub-flooring  14  with a fastener (not shown), such as a staple, nail or adhesive. 
     In  FIGS. 2 and 3 , the shock absorber  22  is illustrated as having six teeth  26   a - 26   f  extending from the base  24 . It will be appreciated, however, that a lesser or greater number of teeth  26  may be used. Each of the teeth  26  is characterized as having a base portion  34  and a tapered portion  36 . The tapered portion  36  has a first face  38  and a second face  40  with the first face  38  being angled relative to the second face  40  such that the intersection of the first face  38  and the second face  40  defines a linear contact edge  42 . When assembled in the floor assembly  10 , the linear contact edge  42  of the shock absorber  22  is placed in contact with the rigid support base  20 . The teeth  26  are compressible under pressure and provide varying resistance dependent on the amount of compression such as providing more resistance as the compression increases. In one embodiment, the linear contact edge  42  is rounded, but the linear contact edge  42  may be formed in a variety of configurations, such as flat or pointed. 
     In one embodiment, the teeth  26  are arranged in a spaced apart relationship with respect to one another. The spacing between the teeth  26  may be equal or variable. In the example shown in  FIGS. 2 and 3 , the teeth  26   c  and  26   d  are spaced a distance apart that is different than the spacing between the other teeth  26   a - 26   c  and  26   d - 26   f . More particularly, the teeth  26   c  and  26   d  are spaced a distance apart to facilitate insertion of a fastener, such as a staple, between teeth  26   c  and  26   d  when attaching the shock absorber  22  to the sub-flooring  14 . 
     In one embodiment, the teeth  26  may be in a parallel relationship with respect to one another, and the teeth  26  may traverse the base  24  from a first edge  50  of the base  24  to an opposing second edge  52 . As described above, the shock absorber  22  may have a substantially rectangular configuration. In such instance, the teeth  26  may be arranged to traverse the base  24  along the width of the base  24 . Also, the outermost teeth  26   a  and  26   f  may be formed to be coextensive with a third edge  54  of the base  24  and an opposing fourth edge  54 , respectively. 
     It will be appreciated that the shock absorber  22  may be formed as a one piece unit using conventional manufacturing processes, such as extrusion or molding processes, and that the shock absorber  22  can be formed from a variety of elastomeric materials, such as rubber, vulcanized rubber, synthetic rubber, PVC, neoprene, nylon, plastisol, or polyurethane. As discussed above, high durometer (hard) resilient shock absorbers  22  produce a floor having preferred ball response characteristics; however, hard shock absorbers  22  provide low shock absorption, and thus have a greater potential to cause harm to the athlete. Yet, floors employing soft shock absorbers  22  do not produce desirable ball response characteristics. By way of example, desirable results have been obtained by constructing the shock absorber  22  from an elastomeric blend having a durometer Shore hardness of about 60. However, durometer Shore hardness in a range between about 50 to about 100 may be suitable. 
     The teeth  26  are dimensioned so that the combination of the base  24  and the teeth  26  provides the desired shock absorbing characteristics that cause the floor assembly  10  to absorb a significant percentage of the impact force of an individual&#39;s foot while maintaining a firmness which controls the deformation of the floor surface  11  and results in a desirable ball response off the floor surface  11 . It should be understood that the number of the teeth, the width to height ratio of the teeth, and the spacing of the teeth may be varied to configure the shock absorber  22  in a way that provides the desired floor characteristics. By way of example, for a ⅜ inch thick shock absorber  22 , desirable results have been obtained when the shock absorber  22  employs six teeth  26  and the teeth  26  having a height in a range of about 9/32 inch to about ¼ inch and a width to height ratio of about 0.75. 
     The strips of wood  12 , the sub-flooring  14 , and the shock absorbers  22 , may cooperate to provide the floor assembly  10  with shock absorbing characteristics that enable the floor assembly  10  to meet flooring standards, such as the “EN Standards.” The EN Standards were developed to ensure that aerobic athletes received a greater degree of safety and performance from a flooring surface when participating in aerobic exercise. The EN Standards focus on three test areas: vertical deflection, shock absorption, and ball deflection. Vertical deflection measures the floor system&#39;s downward movement during the impact of an athlete landing on the surface. Shock absorption measures the floor system&#39;s ability to absorb impact forces normally absorbed by the athlete when landing on a hard surface such as concrete or asphalt. Finally, ball deflection measures the ball&#39;s response off the sports floor system as compared to the ball&#39;s response off concrete. 
     To meet the EN 14904 (2006) Standard, the floor assembly  10  must absorb between about twenty-five and seventy-five percent of an impact force applied to the floor surface  11  while maintaining a firmness that limits vertical deflection of the floor surface  11  of at most about 5.0 mm, and producing a ball response off the floor surface  11  of at least ninety percent. 
     A test pod incorporating the shock absorber  22  illustrated herein having a thickness of about ⅜ inch, in a sample of the floor assembly  10  described above, was tested utilizing the test methods described in the EN 14904 (2006) Standard. The test pod had the shock absorbers  22  spaced at 9.6 inches and aligned to the same orientation. The results of those tests are as follows: 
     
       
         
           
               
            
               
                   
               
               
                 EN 14904 (2006) Standard - Performance Data by Test Point 
               
            
           
           
               
               
               
               
            
               
                   
                 Ball Rebound 
                 Force Reduction 
                 Vertical Deflection 
               
               
                   
                 Required: 
                 Required: 
                 Required: 
               
               
                 Point 
                 Minimum 90% 
                 Minimum 25% to 75% 
                 Minimum &lt;5 mm 
               
               
                   
               
               
                 1 
                 97% 
                 47% 
                 1.8 mm 
               
               
                 2 
                 98% 
                 42% 
                 1.7 mm 
               
               
                 3 
                 98% 
                 41% 
                 1.6 mm 
               
               
                 4 
                 99% 
                 39% 
                 1.4 mm 
               
               
                 5 
                 98% 
                 48% 
                 2.0 mm 
               
               
                 6 
                 95% 
                 47% 
                 2.1 mm 
               
               
                 7 
                 95% 
                 48% 
                 1.9 mm 
               
               
                 8 
                 98% 
                 43% 
                 1.8 mm 
               
               
                 Average 
                 97% 
                 44% 
                 1.8 mm 
               
               
                 Max 
                 99% 
                 48% 
                 2.1 mm 
               
               
                 Min 
                 95% 
                 39% 
                 1.4 mm 
               
               
                   
               
            
           
         
       
     
     From the above description it is clear that the inventive concepts disclosed herein are well adapted to carry out the objectives and to attain the advantages mentioned herein as well as those inherent in the invention. While several embodiments of the invention have been described for purposes of this disclosure, it will be understood that numerous changes may be made which will readily suggest themselves to those skilled in the art and which are accomplished within the spirit of the inventive concepts disclosed and as defined in the appended claims.