Abstract:
A frameless portable suspension system includes a tensional two-dimensional material having a frameless perimeter, opposite upper corners, and a bottom secured to ground, the tensional two-dimensional material located in a vertical plane perpendicular to the ground; a pair of adjustable spring mechanisms coupled to the upper corners and providing the upper corners in tension in an upward vertical direction and a outward horizontal direction, and wherein the tension in the tensional two-dimensional material is adjustable with the adjustable spring mechanisms while the tensional two-dimensional material is under tension and the tensional two-dimensional material is positionable in a vertical plane perpendicular to the ground upon adjustment of the tension in the tensional two-dimensional material with the adjustable spring mechanism.

Description:
FIELD OF THE INVENTION 
   The present invention is in the field of portable sport rebounders and portable sign suspension assemblies. 
   BACKGROUND OF THE INVENTION 
   Sports nets and rebounders have been devised in the past to catch sports balls and/or to rebound sports balls delivered (e.g., thrown, kicked, hit, etc.) at the net/rebounder by a user. These sports nets/rebounders have suffered from a number of drawbacks, one or more of which include: 1) the rebounder does not adequately rebound the sports ball to the user, 2) the sports net/rebounder is difficult and/or time consuming to assembly, 3) the sports net/rebounder is not portable, 4) the sports net/rebounder includes a perimeter frame made of numerous and/or lengthy poles or other supports. 
   SUMMARY OF THE INVENTION 
   The frameless portable suspension system of the present invention represents an improvement over sports nets and rebounders of the past, and may be used in other applications, such as, but not limited to, portable sign suspension. 
   An aspect of the present invention involves a frameless portable suspension system. The frameless portable suspension system includes a tensional two-dimensional material having a frameless perimeter, opposite upper corners, and a bottom secured to ground, the tensional two-dimensional material located in a vertical plane perpendicular to the ground; a pair of adjustable spring mechanisms coupled to the upper corners and providing the upper corners in tension in an upward vertical direction and a outward horizontal direction, and wherein the tension in the tensional two-dimensional material is adjustable with the adjustable spring mechanisms while the tensional two-dimensional material is under tension and the tensional two-dimensional material is positionable in a vertical plane perpendicular to the ground upon adjustment of the tension in the tensional two-dimensional material with the adjustable spring mechanism. 
   Another aspect of the present invention involves a frameless portable suspension system. The frameless portable suspension system includes a tensional two-dimensional material having a frameless perimeter, opposite upper corners, and a bottom secured to ground, the tensional two-dimensional material located in a vertical plane perpendicular to the ground; a pair of adjustable length resilient poles coupled to the upper corners of the tensional two-dimensional material and including a longitudinal center; a pair of tension connectors including ends connected to the pair of adjustable length resilient poles below the longitudinal center to provide flex in the pair of adjustable length resilient poles and opposite ends secured to the ground. 
   A further aspect of the present invention involves a frameless portable suspension system. The frameless portable suspension system includes a tensional two-dimensional material having a frameless perimeter, opposite upper corners, and a bottom secured to ground, the tensional two-dimensional material located in a vertical plane perpendicular to the ground; a pair of adjustable length resilient poles including upper ends coupled to the upper corners of the tensional two-dimensional material and lower ends freely pivotal relative to the ground, and wherein the pair of adjustable length resilient poles provide the upper corners in tension in an upward vertical direction and a outward horizontal direction. 
   Further objects and advantages will be apparent to those skilled in the art after a review of the drawings and the detailed description of the preferred embodiments set forth below. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a rear perspective view of an embodiment of a frameless portable suspension system. 
       FIG. 2  is a rear elevational view of the frameless portable suspension system illustrated in  FIG. 1 . 
       FIG. 3  is a front elevational view of the frameless portable suspension system illustrated in  FIG. 1 . 
       FIG. 4  is a left side elevational view of the frameless portable suspension system illustrated in  FIG. 1 . 
       FIG. 5  is a rear perspective view of an embodiment of a ground anchor of the frameless portable suspension system taken from area  5  in  FIG. 1  and shows the ground anchor connected to a bottom corner of a net of the frameless portable suspension system. 
       FIG. 6  is a rear perspective view of an embodiment of a top end of a telescoping pole assembly of the frameless portable suspension system taken from area  6  in  FIG. 1  and shows the top end of a telescoping pole assembly connected to a top corner of the net of the frameless portable suspension system. 
       FIG. 7  is a rear perspective view of an embodiment of a telescoping connection of the telescoping pole assembly of the frameless portable suspension system taken from area  7  in  FIG. 1 . 
       FIG. 8  is a rear perspective view of an embodiment of a bottom end of the telescoping pole assembly, a ground anchor, and a high-strength strap of the frameless portable suspension system taken from area  8  in  FIG. 1 . 
       FIG. 9  is a top plan view of the frameless portable suspension system illustrated in  FIG. 1 . 
       FIG. 10  is a rear perspective view of an embodiment of a connection section of the telescoping pole assembly and a top end of an adjustable length strap of the frameless portable suspension system taken from area  10  in  FIG. 1 . 
       FIG. 11  is a rear perspective view of an embodiment of a ground anchor and a bottom end of the adjustable length strap of the frameless portable suspension system taken from area  11  in  FIG. 1 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   With reference to  FIGS. 1–11 , and initially  FIG. 1 , a frameless portable suspension system  20  constructed in accordance with an embodiment of the invention will now be described. Although the frameless portable suspension system  20  will be described in a soccer ball rebounding application, the frameless portable suspension system  20  may be used for other sports ball rebounding applications. Further, the frameless portable suspension system  20  may be used for non-rebounding applications such as, but not limited to, portable sign suspension for advertising signs (e.g., advertising new housing/rental developments, advertising political causes/candidates, or other advertising purposes). 
   The frameless portable suspension system  20  generally includes a tensionable two-dimensional material or net  30 , a pair of telescoping pole assemblies  40 , a pair of adjustable length straps  50 , a pair of high strength straps  60 , and multiple ground anchors  70 . Each of these components will be described in turn below. 
   In the embodiment shown, the tensionable two-dimensional material  30  is a sport net that is tensionable in both vertical and horizontal directions to be taught yet flexible enough to withstand and repel large impact forces such as those produced by various sports balls traveling at high velocity that contact the net  30  or high velocity wind. In the embodiment shown, the net  30  is rectangular and includes the same dimensions as the goal opening in a regulation soccer goal (8 ft. in height×24 ft. in length). As used herein, “two-dimensional material” refers to materials such as flexible signs, nets stretchable into a flat configuration, and the like that when placed in tension have a configuration that is substantially in two main dimensions (i.e., substantial length and substantial width compared to thickness). The net  30  includes an upper right corner  80 , an upper left corner  90 , a bottom right corner  100 , and a bottom left corner  110 . As used herein, “frameless” means the two-dimensional material  30  does not have a frame along a substantial portion of the perimeter. In the frameless portable suspension system  20 , the vertical and horizontal tension placed on the net  30  at the upper corners  80 ,  90  by the telescoping pole assemblies  40  maintains the net  30  in the configuration shown in  FIGS. 1–3 . Although the tensionable two-dimensional material  30  is shown and described as a soccer sports net, in alternative embodiments, the tensionable two-dimensional material  30  may be other tensionable materials such as, but not limited to, a flat fabric panel such as that used for an advertising sign. 
   With reference to  FIGS. 1 and 7 , the telescoping pole assembly  40  is a two-piece adjustable-length fiberglass pole and includes an 82 in., 1.00 in. outer diameter upper pole member  120  slidably received in a 82 in., 1.25 in. outer diameter lower pole member  130  for conveniently increasing and decreasing the length of the pole assembly  40 . When the pole assembly  40  is set to the desired length (i.e., when the upper pole member  120  is moved to the desired position in lower pole member  130 ), the length of the pole assembly  40  is fixed using a plastic compression fitting including a threaded collar  140  and an externally threaded connector  150 . The length of the pole assembly  40  is locked by rotating and tightening internally threaded collar  140  onto externally threaded connector  150 . 
   With reference to  FIG. 6 , the pole assembly  40  includes an upper end  160  with a cap  170  fixed thereto. The cap  170  carries a circular connector  180  that couples the upper end  160  to the upper corners  80 ,  90  through a carabiner  190 . Although the connection of the upper end  160  of the pole assembly  40  is shown as including a cap  170 , a circular connector  180 , and a carabiner  190 , in alternative embodiments, the connection may include one or more of these connector elements or one or more different connector elements. 
   With reference to  FIG. 8 , the pole assembly  40  includes a lower end  200  with a cap  210  fixed thereto. Spaced above the cap  210  is a stop  220  (with circular lip) circumferentially and longitudinally fixed to the circumference of the lower pole member  130 . The high strength strap or connector  60  is made of 1 in. nylon webbing rated at 600 lb. breaking strength and is connected at one end portion to the lower pole member  130  between the stop  220  and the cap  210  and connected at an opposite end portion to a head  230  of ground anchor  70 . The stop  220  prevents the strap  60  from sliding past the stop  220  on the pole assembly  40 . In the embodiment shown, the ground anchor  70  is a plastic ground stake with a shaft  240 . In alternative embodiments, one or more of the ground anchors  70  may have the same or a different construction/configuration from that shown in  FIGS. 1–8  or may have the same or a different construction/configuration from the other ground anchors  70 . For example, but not by way of limitation, the ground anchor  70  may be a ground auger. When inserted into or connected to the ground, the ground anchors  70  form anchor points with the ground. Further, in an alternative embodiment of the suspension system  20 , especially where the ground is a hard surface (e.g., wood, cement, etc.), the ground anchors  70  may be replaced with permanent anchor points (e.g., in an inside environment with a hard floor, in an outside environment with a hard support surface). 
   Utilizing a flexible connection between the lower end  200  of the pole assembly  40  and the ground anchor  70  allows the lower end  200 , when not under load, to move in a 360 degree arc, at a maximum radius equal to the distance of the high strength strap  50 , relative to the ground anchor  70  and allows the pole assembly  40  to pivot freely within a possible 180 degree range at the lower end  200  relative to the ground. When under load and in response to dynamic loads, the pole assembly  40  pivots freely at the lower end  200  relative to the ground, adding to the flexibility of the frameless portable suspension system  20 . 
   With reference to  FIGS. 1 ,  10 , and  11 , the adjustable length strap or tension connector  50  is made of 1 in. nylon webbing rated at 600 lb. breaking strength and connects below a longitudinal center  270  of the pole assembly  40  to a ground anchor  70 . An upper end of the adjustable length strap  50  is connected below the longitudinal center  270  of the pole assembly  40 , above a stop  280  (with circular lip), which is circumferentially and longitudinally fixed to the circumference of an upper part of the lower pole member  130 . The stop  280  prevents the strap  60  from sliding past the stop  280  on the pole assembly  40 . The adjustable length strap  50  is connected at an opposite lower end to the head  230  of ground anchor  70 . The adjustable length strap  50  includes a strap length adjustment mechanism  290  (e.g., adjustable cam lock rated at 600 lbs.) for quickly and easily adjusting the length of the strap  50 . 
   The length of the strap  50  may be decreased to increase the pull rearwardly on the pole assembly  40  below the longitudinal center  270 . This causes the pole assembly  40  to bow or flex upwardly and rearwardly as shown in  FIG. 4 , and causes the pole assembly  40  to pull the upper corner  80 ,  90  of the net  30  rearwardly. To increase the vertical and horizontal tension in the net  30  (increase the rebounding effect of the net  30  and the frameless portable suspension system  20 ) while maintaining the net  30  in a vertical plane perpendicular to the ground shown in  FIG. 4 , the length of the pole assembly  40  is increased and the length of the adjustable length strap  50  is decreased. Increasing the length of the pole assembly  40  causes the pole assembly  40  to push the upper corner  80 ,  90  of the net  30  forward; however, decreasing the length of the adjustable length strap  50  causes the pole assembly  40  to bow upwardly and rearwardly as shown in  FIG. 4 , and causes the pole assembly  40  to pull the upper corner  80 ,  90  of the net  30  rearwardly so that the net  30  is maintained in a vertical plane perpendicular to the ground. The bent pole assemblies  40  in combination with the adjustable length straps  50  stretch the net  30  vertically and horizontally. The bowed pole assemblies  40  (in combination with the adjustable length straps  50 ) effectively form adjustable spring mechanisms that pull vertically upward and horizontally outward at the upper corners  80 ,  90 , and greatly enhance the rebounding properties of the stretched net  30 . In an opposite manner, to decrease the vertical and horizontal tension in the net  30 , the length of the strap  50  may be increased to decrease the pull rearwardly on the pole assembly  40  below the longitudinal center  270  and the length of the pole assembly  40  may be decreased. Because the pole assemblies  40  are able to pivot freely while the net  30  is under tension, a user may easily vary the tension in the net  30  in both vertical and horizontal directions while the net  30  is under load and maintaining the net  30  in a vertical plane perpendicular to the ground. 
   With reference to  FIGS. 1 and 5 , the bottom corners  100 ,  110  are secured to the ground at anchor points with the ground anchors  70 . In the embodiment of the ground anchor  70  shown in  FIG. 5 , the ground anchor  70  has a different configuration than the ground anchors  70  that hold the pole assemblies  40  and adjustable length straps  50  to the ground. The ground anchor  70  illustrated in  FIG. 5  includes a head  300  with a crook  310  that catches the corner  100 ,  110  of the net  30  for securing the corner  100 ,  110  to the ground at anchor points. As shown in  FIGS. 1–3  and  9 , additional ground anchors  70  similar to that shown in  FIG. 5  may be utilized at various positions along the bottom of the net  30  to secure the bottom of the net  30  to the ground at anchor points. 
     FIG. 9  illustrates the frameless portable suspension system  20  in an assembled configuration. In this configuration, the net  30  is in a vertical plane perpendicular to the ground, the lower ends  200  of the telescoping pole assemblies  40  extend inwardly and rearwardly relative to the upper corners  80 ,  90 , and the adjustable length straps  50  extend rearwardly and inwardly from below the longitudinal center  270  of the pole assemblies  40  to the ground anchors  70 . The inner anchors  70  are generally aligned and a line drawn therethrough is generally perpendicular to the vertical plane of the net  30 . 
   An exemplary method of assembling the frameless portable suspension system  20  will now be described. To assemble the frameless portable suspension system  20 , the net  30  is first unrolled/unraveled and spread out in the desired location (i.e., the net  30  is positioned). Next, the bottom corners  100 ,  110  of the net  30  are secured to the ground with ground anchors  70  (See  FIG. 5 ). The back ground anchors  70  are then installed behind the net as shown in  FIG. 9 . The upper ends  160  of the telescoping pole assemblies  40  are connected to the upper corners  90 ,  100  of the net  30  (See  FIG. 6 ). The lower ends  200  of the telescoping pole assemblies  40  are then connected to the ground anchors  70  via the high strength straps  60  (See  FIG. 8 ). Next, the right pole assembly  40  (when looking at the front of the net  30  as in  FIG. 3 ) is pre-tensioned (i.e., the right pole assembly  40  is adjusted to a desired initial length). Then, the left pole assembly  40  is pre-tensioned and the adjustable length strap  50  is pre-tensioned (strap  50  is adjusted to desired initial length). The right pole assembly  40  is then final tensioned (i.e., the right pole assembly  40  is fine-tuned to the final desired length that provides the desired amount of rebound in the net  30 ) and the right adjustable length strap  50  is tightened/shortened to a length that causes the net  30  to be within a vertical plane perpendicular to the ground as shown in  FIG. 9 . The left pole assembly  40  is then final tensioned or fine-tuned to the final desired length that provides the desired amount of rebound in the net  30  and the left adjustable length strap  50  is tightened/shortened to a length that causes the net  30  to be within a vertical plane perpendicular to the ground as shown in  FIG. 9 . The bottom of the net  30  between the bottom corners  100 ,  110  is then secured to the ground with the intermediate ground anchors  70 . The frameless portable suspension system  20  is then ready for use. 
   An exemplary method of using the frameless portable suspension system  20  as a sports ball rebounder, and, in particular, a soccer ball rebounder, will now be described. A user faces the soccer net  30  of the frameless portable suspension system  20  in the orientation shown in  FIG. 3 . The user kicks a soccer ball at the net  30 . The soccer ball hits the net  30 , causing the net  30  to move rearward, especially the area of the net  30  where impact occurs. Because the net  30  is in a high state of tension (in both the vertical and horizontal directions) by the pole assemblies  40  and adjustable length straps  50 , and the pole assemblies  40  effectively function as spring mechanisms, a high percentage of the energy absorbed by the frameless portable suspension system  20  when the soccer ball hits the frameless portable suspension system  20 , is returned to the soccer ball and the soccer ball is rebounded back towards the user. It should be noted, not only is the frameless portable suspension system  20  ideal for use as a soccer rebounder practice device  20 , but because the net  30  is the same dimension as the opening of a regulation soccer goal, the soccer rebounder practice device  20  also ideally functions as a portable soccer goal, which can be set up on any field. 
   Because the frameless portable suspension system  20  lacks a perimeter frame and only uses two telescoping pole assembly  40 , one net  30 , two adjustable length straps  50 , two high strength straps  60 , and anchors  70 , the frameless portable suspension system  20  is very light-weight, very easy to assemble, and inexpensive to manufacture (especially in view of the relatively short pole length of the pole assemblies  40  compared to prior art nets/rebounders where perimeter pole frames or other pole-intensive assemblies were used). The frameless portable suspension system  20  also allows a user to easily vary the tension in the net  30  in both vertical and horizontal directions while the net  30  is under load and keeps the net  30  in a vertical plane perpendicular to the ground. The frameless portable suspension system  20  absorbs the blow of large forces such as those produced by a high-velocity soccer ball or a player accidentally running into the net  30  while also exhibiting exceptional rebounding properties. 
   Different-sized nets  30  may be used with the same frameless portable suspension system  20 . For example, but not by way of limitation, a user may replace the net  30  with a different-size net  30  (e.g., for another size goal such as a smaller youth dimension) without having to change out the remainder of the frameless portable suspension system  20 . Also, the surface and contour of the net  30  may be shaped by changing the position of where the ground anchors  70  for the central portion of the net  30  secure the central portion of the net  30  to the ground. For example, by placing these central ground anchors  70  aft of the line formed by the corners  100 ,  110 , the shape of the net  30  will become partly concave so that rebounds from the sides of the net  30  are directed towards the center of the playing area in front of the net  30 . 
   Another advantage of the frameless portable suspension system  20  is the large amount of vertical and horizontal tension that the pole assemblies  40  (in combination with the adjustable length straps  50 ) are able to put on the net  30 . This is a main reason why the frameless portable suspension system  20  functions so well as a sports ball rebounder and is able to return such a large amount of the energy imparted on the frameless portable suspension system  20  with the sports ball. A series of vertical and horizontal tension tests were conducted near the upper corners  80 ,  90  of the net  30 . At a pole assembly length of 139.75 in., the vertical tension near the upper corners  80 ,  90  was 8.5 lbs. to move this portion of the net  30  down 1 in. At a pole assembly length of 142.75 in., the vertical tension near the upper corners  80 ,  90  was 14.5 lbs. to move this portion of the net  30  down 1 in. At a pole assembly length of 145.75 in., the vertical tension near the upper corners  80 ,  90  was 16.5 lbs. to move this portion of the net  30  down 1 in. At a pole assembly length of 148.75 in., the vertical tension near the upper corners  80 ,  90  was 18.0 lbs. to move this portion of the net  30  down 1 in. At a pole assembly length of 142.75 in., the horizontal tension near the top center of the net  30  was 10.5 lbs. At a pole assembly length of 145.75 in., the horizontal tension near the top center of the net  30  was 11.5 lbs. At a pole assembly length of 148.75 in., the horizontal tension near the top center of the net  30  was 12.5 lbs. 
   It will be readily apparent to those skilled in the art that still further changes and modifications in the actual concepts described herein can readily be made without departing from the spirit and scope of the invention as defined by the following claims.