Abstract:
A fence surrounds a trampoline and extends above the rebounding surface, reducing the risk of injury. Shock absorption is aided by a support system of independent poles, linked at their tops by a flexible strap or line which is attached directly to a protective cap at the top of each pole. Also disclosed are a method and apparatus for attaching a pad to a trampoline frame either with or without an enclosure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 60/914,312, filed Apr. 26, 2007. 
    
    
     BACKGROUND AND SUMMARY 
     The present invention concerns wall structures used with trampolines to protect trampoline users and to provide new uses for trampolines. 
     In the past, trampolines have been used for a variety of athletic and recreational purposes. However, injuries have sometimes resulted when a person jumping on a trampoline would land too near the boundary of the rebounding surface and strike the trampoline frame or fall from the trampoline to the ground. An article in the Mar. 3, 1998 , New York Times  reports that trampoline-related emergency room hospitalizations of children doubled between 1990 and 1995 (to nearly 60,000), and that the rate of injuries shows no sign of abating. Some in the medical community have called for a ban on the sale of home trampolines. While stopping short of a ban, the U.S. Consumer Products Safety Commission has called for safety improvements to home trampolines. 
     One approach to reducing such injuries has been to form a wall around the perimeter of a trampoline bed so that when a jumper lands too near the edge, the wall prevents the jumper from falling off. For example, U.S. Pat. Nos. 6,261,207 and 6,053,845 illustrate a perimeter wall that forms a resilient enclosure. 
     While using a trampoline, there is also danger that the person may fall onto the frame or into the area between the bouncing surface and the trampoline frame. Consumer protection safety laws require trampolines to have some type of pad on the trampoline frame. Trampoline safety pads cover the trampoline frame and trampoline springs so as to satisfy these regulations and provide a safer trampoline. 
     Ties, cords or straps are used to attach the safety pads to the trampoline frame. A common method of attaching the pad to the frame is the use of narrow straps or cords. These straps are wrapped around the frame, pass through an opening in the pad and are then tied off or secured on the outside surface of the pad. 
     The means currently employed to secure safety pads to the trampoline frame have shortcomings. First, current ties have a very small amount of surface contact with the frame. Consequently, the ties are able to slip and shift quite easily along the frame. This is undesirable because the pad may interfere with the bouncing surface. Second, ties are secured to the trampoline frame itself, which does not keep them in the proper position relative to the trampoline rebounding surface, which can shift inward and expose a gap between the edge of the rebounding surface and the edge of the trampoline. 
     Improved trampoline safety enclosure systems and construction methods are described herein. 
     As described herein, a trampoline safety enclosure system has a novel protective cap. The configuration of the protective cap enables a flexible strap or line at the upper edge of the netting material to be attached directly to it so that the top surface of the protective cap is nearly even with the upper edge of the netting material. In this way, protrusion of the protective cap and potential for injury to the jumper are minimized. 
     A trampoline pad and a method and apparatus for attaching the trampoline pad to a trampoline frame are described, wherein a cord is attached to the pad by means of an assembly having an upper disk with a hole or plurality of holes on top of the pad and a lower disk with a hole or plurality of holes below the pad. The cord is looped through the upper disk, the pad, the lower disk, and is then attached to the ring of the bouncing surface by means of a rigid connector which forms a “T” at the end of the cord. This arrangement may be utilized for a trampoline either with or without a trampoline safety enclosure system. 
     Also described are a trampoline pad and a method and apparatus for attaching the trampoline pad to a trampoline frame, wherein a cord is attached to the pad by means of a two-piece assembly having an upper part on top of the pad, a lower part below the pad, and a fastener connecting the two by means of a hole or other opening in the pad. The cord is looped through the lower part and then attached to the ring of the bouncing surface by means of a rigid connector which forms a “T” at the end of the cord. This arrangement also may be utilized for a trampoline either with or without a trampoline safety enclosure system. 
     A trampoline pad and a method and apparatus for attaching the trampoline pad to a trampoline frame using a cord with a rigid connector which forms a “T” at one end also is described. A cord is attached to the pad by means of a two holes or an attachment point. The cord is looped around the frame of the trampoline and attached to a rigid connector. This arrangement may be utilized for a trampoline either with or without a trampoline safety enclosure system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an oblique view showing a trampoline apparatus including an enclosure system. 
         FIG. 2  is an enlarged vertical cross-sectional view of the protective cap at the top of the pole. 
         FIG. 3  is a cross sectional view of a first apparatus for attaching a pad to a trampoline frame. 
         FIG. 4  is an exploded oblique view showing the individual components used in the attachment apparatus of  FIG. 3 . 
         FIG. 5  is an oblique view of the apparatus of  FIG. 3 , showing the attachment of a cord to a bed ring. 
         FIG. 6  is an enlarged vertical cross-sectional view of a second apparatus for attaching a pad to a trampoline frame. 
         FIG. 7  is an exploded oblique view showing the individual components used in the attachment device assembly of  FIG. 6 . 
         FIG. 8  is an enlarged vertical cross-sectional view of a third apparatus for attaching a pad to a trampoline frame. 
         FIG. 9  is a bottom plan view showing the assembly used in the attachment device assembly of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     A general description of a suitable trampoline is provided below in order to establish a context in which to understand the present invention. However, it should be noted that the applications in which the present invention may be used are not limited to the trampoline described below. 
     Generally, a trampoline, as shown in  FIG. 1 , consists of a frame  10 , a bouncing surface  14  and springs  12 . The frame  10  provides support for the bouncing surface  14 , and is linked to the bouncing surface  14  via the trampoline springs  12 . The frame  10 , springs  12  and bouncing surface  14  are conventional. 
     The trampoline frame  10  is supported by U-shaped legs  19 . In a preferred embodiment, these frame members are cylindrical steel tubes. In  FIG. 1 , the horizontal frame members  6  are attached to form a circle-shaped trampoline frame  10 . However, the trampoline frame members could be joined to form a variety of shapes including a hexagon, rectangle, octagon and an ellipse. 
     In  FIG. 1 , the bouncing surface  14 , like the frame  10 , is circular in shape. Also, like the frame  10 , the bouncing surface  14  can have a variety of shapes such as hexagonal, elliptical, rectangular or octagonal. The bouncing surface  14  provides an elasticized area for individuals to perform activities such as acrobatics, flips and various exercises. It is attached to and held by the trampoline frame  10  using trampoline springs  12 . It is preferred to use trampoline springs  12 ; however, the bouncing surface  14  may be secured by any means capable of attaching the bouncing surface  14  to the frame  10  and creating a biased, resilient connection between the bouncing surface  14  and the frame  10 . The trampoline springs  12  are attached at one end to the bouncing surface  14  and are attached at the other end to the frame  10 . 
     The bouncing surface  14  is disposed within the circumference of the frame  10  and the frame  10  is situated radially outward of the bouncing surface  14 . With this frame of reference, in the following description horizontal movement towards the bouncing surface  14  is referred to as “radially inward” and horizontal movement away from the bouncing surface  14  is referred to as “radially outward.” 
     The basic elements of the trampoline enclosure system work to prevent the user from bouncing beyond the edges of the trampoline surface. The system includes fence poles  15  which attach to the U-shaped legs  19  of the trampoline. Above the surface of the trampoline bed these poles are covered by padding  6 . The fence poles support netting material  4 , which extends from the surface of the trampoline bed  14  to protective caps  17 . The upper edge of netting material  4  is further reinforced by a flexible line  2  which runs along its upper edge. Flexible line  2  is also connected to the protective caps  17 . 
     One arrangement of an enclosure protective cap is shown in  FIG. 2 . Protective cap  17  fits on the top of fence pole  15 . The protective cap defines an upwardly opening slot  13  proportioned such that its lower edge may be aligned with and fit into cutouts  11  at the top of fence pole  15 . With this arrangement, a solid connection made between the fence pole  15  and protective cap  17  which does not allow the cap to rotate. The protective cap is further reinforced by the edge of the fence pole so that it can better withstand forces applied by the flexible line  2 . The protective cap slot is narrowed at its upper region and widens at its base, such that the flexible line may be passed into the slot, and then tends to remain within the lower region of the slot during normal use. The top surface of the protective cap is nearly even with the upper edge of the netting material reducing potential for injury to the user. The upper region of the protective cap is domed to create a large surface area. This also helps to prevent injury to the user in case of impact with the protective cap. The mid section  18  of the cap is narrowed so that its inner diameter conforms to the outer diameter of fence pole  15  to provide a snug fit. The lower section  19  of the protective cap widens such that its inner diameter conforms to the outer diameter of padding  16  to provide a snug fit. 
     The protective caps  17  on the ends of the fence poles can have various forms. For example, a domed cap can be used as shown in  FIG. 2 , manufactured of a somewhat soft material to dampen impacts, while still providing protection from the top end of the support pole. The cap can be filled with foam or caulk for increased shock absorbency. The cap can also be provided with an accordion-type wall configuration, to enhance its shock absorbing ability. The size of the cap can be increased, to enlarge the surface area that an impacting body hits, and the cap can be bent (typically outwardly) to provide more ready deformability. Combinations of the above-described protective cap features also may be used. 
     As shown in  FIG. 1 , one or more trampoline safety pads  20  are attached to a trampoline frame  10 . The pad  20  is placed on the frame so as to cover the springs  12  and frame  10  and provide protection to the user from impact. Each trampoline safety pad  20  partially or completely covers trampoline springs  12 , which hold a bouncing surface  14  to the trampoline frame  10 . The safety pad  20  may be comprised of closed cell polyethylene foam and/or comprised of materials such as cross-linked polyethylene, open celled polyurethane and rim molded polyurethane. Best results are achieved when the foam used to construct the pad  20  is high density foam. 
     In the arrangement seen in  FIG. 3 , an upper disk  40  is attached on the upper surface of the safety pad  20  and a lower disk  42  is attached to the lower surface of the safety pad  20  and connected by means of a cord  34  passing through a trampoline safety pad hole  22  and tied in a knot on both sides. In the illustrated arrangement, safety pad hole  22  consists of a larger opening of material cut out from the foam pad as well as a smaller opening of material cut out from both the upper and lower cover of the pad. The opening of the hole is reinforced with a sewn grommet of PVC or other similar elastomeric material which binds the upper and lower cover of the pad together. Another arrangement of the safety pad hole is an opening which is reinforced with a sheet metal grommet. The other end of the cord  34  is connected to a rigid connector piece  32 .  FIG. 4  shows the relationship between the components mentioned in this arrangement. The rigid connector piece  32  is then attached to a bouncing surface ring  30  as shown in  FIG. 5 . 
     The following explains a method of attaching the trampoline safety pad  20  to a trampoline frame  10 . The trampoline safety pad  20  is positioned so that trampoline pad holes  22  match with bouncing surface rings  30 . For each trampoline pad hole  22 , either the upper disk  40  and lower disk  42  or upper assembly part  50  and lower assembly part  52  should be attached to the safety pad  20  and connected to the rigid connector piece  32  with the cord  34 . The rigid connector piece  32  is then attached to the bouncing surface ring  30 . The foregoing steps should be repeated until all holes  22  in the trampoline safety pads  20  have been used. 
     The arrangement seen in  FIG. 6  shows upper assembly part  50  and lower assembly part  52  that are attached to the safety pad  20  and fastened by a bold  54  passing through the trampoline safety pad hole  22  and secured at the other end by a nut  56 . Cord  34  passes through a hole  56  in the lower assembly part  52  and is connected to the rigid connector piece  32 .  FIG. 7  shows the relationship between the components of this arrangement. The rigid connector piece  32  is then attached to the bouncing surface ring  30  as shown in  FIG. 5 . 
     An additional arrangement is seen in  FIG. 8 . Cord  34  is attached to the rigid connector piece  32 . It begins on one side of trampoline frame  10 , passes through hole  60  in the lower safety pad cover and exits hole  62  in the lower safety pad cover. It then passes back around trampoline frame  10  and is looped over the rigid connector piece  32 .  FIG. 9  shows the relationship between the components of this arrangement. 
     Through use of the rigid connector to the bed of the trampoline, the connection between the pad and the bouncing surface is easily and quickly removable without the use of tools. The use of the elastic type cord keeps the pad centered over the springs to provide the required protection, but absorbs the shock and energy of impact. This serves to prevent damage to the pads caused when the user bounces onto the pads. One consideration is the length of elastic cord connecting the safety pad to the bouncing surface ring. It is advantageous to allow a slack length of elastic cord such that the pad must be displaced prior to the cord being engaged. This serves to prolong the life of the cords by reducing the forces and strain during normal use. 
     It should be understood that many changes and modifications can be made to the arrangements described above. For example, although some of the methods and apparatus described herein relate to attaching a pad to a trampoline, such methods and apparatus are useful for other devices in which one must attach a pad to a frame. It is therefore intended that the foregoing detailed description be understood as an illustration of embodiments, and not as a definition of the invention. It is only the following claims, including all equivalents that are intended to define the scope of this invention.