Abstract:
The trampoline with inflated base includes a generally toroidal shaped inflatable tube having an open center area. A mesh rebound member extends over the open center area and is secured around its entire periphery to the tube on the upper surface of the tube member. The tube includes a singular air duct or a plurality of air ducts extending radially which allow communication of air between the space interior to the tube and the space exterior to the tube.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to the US provisional application, having Ser. No. 61/021,603 for a “Trampoline with Inflated Base”, which was filed on Jan. 16, 2008, and which is incorporated herein by reference 
     
    
     BACKGROUND OF INVENTION 
       [0002]    The present invention relates to recreational trampolines, and in particular trampolines having an inflated base so they are capable of floating on water. 
         [0003]    Water trampoline devices are well known in the art. Examples of such water trampolines are shown in U.S. Pat. No. 4,576,375 to Roberts; U.S. Pat. No. 5,810,695 to Sass; and U.S. Pat. No. 7,150,699 to Roth, among others. 
         [0004]    Typically, the devices include an inflatable tube in the shape of a ring or doughnut, but other variations include square or rectangular shapes. The device also includes a central rebounding or bed portion, which is typically a tightly woven mesh, and is connected around its outer periphery to the inflatable tube, typically near the top of the tube. This bed portion extends over the central opening of the tube wherein the mesh or a comparable elastic surface member forms the rebound member. Various securing/attaching elements are known to connect the rebound member and the tube, including rubber strands, such as shown in the &#39;375 patent, or more typically, springs or bungee-type devices, such as shown in the &#39;695 patent and in U.S. Pat. No. 5,385,518 to Turner. Generally, those devices having metal springs have a greater efficiency in absorbing and returning the energy of a jumper, and thus provide a higher performance bounce. The device is commonly referred to as a water trampoline because the inflatable tube can float on water, but may also be used on land if so desired. 
         [0005]    However, such water trampolines are still inferior in rebounding efficiency to larger trampolines that are extended off the ground by a heavy metal frame. 
         [0006]    It is therefore a first object of the present invention to provide a water trampoline of superior rebounding efficiency. 
       SUMMARY OF INVENTION 
       [0007]    In the present invention, the first object is achieved by providing a trampoline with inflated base that comprises a generally toroidal shaped inflatable tube having an open center area, a rebound member configured to extend over the open center area of the inflatable tube, the rebound member providing a trampoline effect for a user when the rebound member is operatively secured to the tube. The tube includes a singular air duct or a plurality of air ducts extending radially between the central open area within the tube and the outside of the tube which allow communication of air between the space interior to the tube and the space exterior to the tube. 
         [0008]    The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of the trampoline of the present invention. 
           [0010]      FIG. 2  is a plan view of the top and cross-section of the trampoline of  FIG. 1 . 
           [0011]      FIG. 3  is an elevational view of the front of the trampoline of  FIG. 1 . 
           [0012]      FIG. 4  is a perspective view of a second embodiment of the trampoline of the present invention. 
           [0013]      FIG. 5  is a plan view of the top and cross-section of the trampoline of  FIG. 4 . 
           [0014]      FIG. 6  is an elevational view of the front of the trampoline of  FIG. 4 . 
           [0015]      FIGS. 7A-D  are four perspective views, each of a different embodiment of the air duct reinforcement. 
           [0016]      FIG. 8  is a perspective view of a third embodiment of the trampoline of the present invention. 
           [0017]      FIG. 9  is a partial perspective view of an inflation valve feature of the trampoline of  FIG. 1-3 . 
           [0018]      FIG. 10  is a cross-sectional view of the inflated base for the trampoline showing the air duct. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring to  FIGS. 1 through 10 , wherein like reference numerals refer to like components in the various views, there is illustrated therein a new and improved trampoline with inflated base, generally denominated  10  herein. 
         [0020]    It has not been completed appreciated by those of ordinary skill in the art that another significant factor determining the performance of these rebounding devices is energy which is lost in the movement of the bed. One of the components of this factor include the density of the weave of the mesh fibers and how they restrict airflow as the bed moves up and down. Most recreational based trampolines utilize a bed with a relatively densely woven mesh, which greatly restricts airflow. Another component of bed performance is the ability for the surrounding air to move in the space directly above and below the bed. Normally the inflatable tube surrounding the periphery of the space below the bed is a confined closed space or chamber. Because of this, the bed must compress air in the chamber as it travels downward, and the bed must pull against a partial vacuum in the chamber as it travels back upward. The net effect on the bed is energy loss, which results in decreased bounce performance. 
         [0021]    In light of the foregoing discoveries and in accordance with the present invention it is desirable that a water trampoline has a vented lower chamber, to allow for greater airflow and increased bounce performance.  FIGS. 1-3  show the complete water trampoline of an embodiment of the present invention in which water trampoline  10  includes an inflatable tube  12  in the shape of a toroid, which has a circular perimeter. Additional embodiments of the invention include tubes  12  with perimeter shape of a square, rectangle, pentagon, hexagon, octagon, decagon, or dodecagon. The tube  12  itself can be of various cross-sectional diameters; and the diameter of the toroid configuration can also vary. In one embodiment, the toroid has an outside diameter of 15 feet, while the tube has a cross-sectional diameter of approximately 3 feet. In the embodiment shown, tube  12  is 28 ounce 1000 denier polyester reinforced PVC material, which is a heavy-duty plastic and resistant to puncture. Again, however, different materials can be used. 
         [0022]    At the upper surface portion of tube  12  is a resilient rebound element  16 . In the embodiment shown, rebound element  16  is preferably a polypropylene mesh fabric, in the shape of a dodecagon, and covers the central opening of the toroidal tube at the upper surface thereof. In additional, rebound elements  16  and tube  10  may be configured in numerous shapes including, but not limited to, a hexagon, octagon, decagon, and a circle. The mesh material is well known and therefore not described in more detail. 
         [0023]    In the embodiment shown, for a 15 foot toroidal tube, rebound element  16  is preferably about 10 feet in diameter. Rebound element  16  is sufficiently suspended by springs  20  attached to a frame  18  provide a trampoline effect when jumped on by a user. The frame  18  is secured along its outer peripheral edge  19  to the inflatable toroidal tube  12 , near the upper or top edge of the tube  12 . 
         [0024]    Water trampoline  10  will typically, but not necessarily, include additional (accessory) elements not shown, including an anchor with an anchor rope attached to the tube  12 . In one embodiment, the anchor rope is approximately 12 feet long and the anchor is a PVC bag with a 20-pound weight therein. Although not shown in the embodiment, water trampoline  10  may include at least one ladder, which extends downwardly into the water from inflatable tube  12  from attachment points on the outer periphery of the tube. A ladder can be made, for instance, of lengths of rope with horizontal wood slats or rods extending therebetween. The ladder is used by a swimmer to ascend onto the water trampoline. 
         [0025]    In the embodiment shown, inflatable tube  12  has air ducts  22  which allow air to pass between the space interior to the inflatable tube and the space exterior to the inflatable tube. As shown, the ducts are channels with a generally circular cross section, arranged radially on the horizontal plane at the midpoint of the height of tube  12 . Although the ducts of the preferred embodiment are have a generally circular cross section, ducts having rectangular, triangular, elliptical, or other cross sections may be used in alternative embodiments. When a user jumps and falls downward into rebounding surface  16 , the rebounding surface travels downward. The volume of air contained in the space defined between the surface of the water and the rebounding surface  16  and within the inner diameter of toroidal tube  12  decreases as the rebound surface moves downward. Air is pushed out through the air ducts  22  to the ambient air exterior to the inflated tube  12 . As the user bounces back upward, the rebounding surface travels upward. The volume of air contained in the space defined between the surface of the water and the rebounding surface  16  and within the inner diameter of toroidal tube  12  then increases as the rebounding surface moves upward. Air is drawn in through the air ducts  22  from the ambient air exterior to the inflatable tube. By allowing the air to travel through the ducts  22 , the bed is able to move more rapidly and freely. This decreases the energy loss associated with the movement of the bed, thus increasing the bounce performance of the trampoline. 
         [0026]    Because toroidal tube  12  is inflated, its internal pressure will naturally have a tendency to force the walls  13  of the ducts together at the midpoint if they are unsupported. This is clearly illustrated in the plan view shown in  FIG. 2 . Because of this effect, the ducts may be sized with a larger diameter at both ends  11  and the material of the inflated tube may be cut accordingly to provide a corresponding minimum diameter at the midpoint  15  through the toroidal tube. 
         [0027]    In a second embodiment of the water trampoline shown in  FIGS. 4-7  the ducts  22  maintain a circular cross section of consistent diameter along their length. This embodiment includes means of reinforcing the walls of the ducts to counteract the compressive forces applied by the internal pressure of inflated tube  12 . The function of the ducts is similar to the embodiment shown in  FIGS. 1-3 . Air is allowed to travel through the ducts, thereby improving bounce performance as previously described.  FIGS. 7A-D  illustrate four different embodiments of wall reinforcement elements.  FIG. 7A  shows a cylindrical reinforcement tube  40  with a solid wall having exterior surface  42  and interior surface  44 . Reinforcement tube  40  is inserted into duct  22  prior to inflation of the tube  12 . As tube  12  is inflated, the internal air pressure within the tube forces duct wall  13  against the exterior surface of the reinforcement tube  42 . The resulting friction between the two surfaces causes reinforcement tube  40  to be securely held in place. When installed, the inner surface  44  becomes the open duct which allows airflow between the inner and outer space of inflatable tube  12 . The reinforcement embodiments shown in  FIG. 7B-D  may be installed in a similar manner. 
         [0028]      FIG. 7B  shows inflatable reinforcement tube  50  having outer surface  52  and inner surface  54 . An uninflated reinforcement tube  50  is inserted into duct  12  and inflated to a pressure higher than inflatable tube  12 . Inflatable tube  12  is then inflated as previously described. Because of the pressure is higher tube  50  than in tube  12 , it is able to resist the inward forces of the duct wall  13 . 
         [0029]    As shown in  FIG. 7C , reinforcement tube  60  has a plurality of rigid annular support rings  62 . The rings are connected by tubing material  64  which in the preferred embodiment is flexible. Alternate embodiments include the use of a rigid tubing material  64 .  FIG. 7D  shows reinforcement tube  70  composed of helically wound rigid material  72 . 
         [0030]      FIG. 8  illustrates an alternative embodiment of the present invention. It utilizes an inflatable toroidal tube  12 . Rebounding surface  16 , springs  20  and upper frame  19  are supported by vertical supports  82  and lower frame  80 . The separation between upper frame  19  and lower frame  80  create openings  84  between each vertical support  82  about the circumference of the frame. These openings  84  allow air to pass between the space interior to the inflatable tube and the space exterior to the inflatable tube. The function of these openings  84  is similar to the ducts  22  shown in the embodiment of  FIGS. 1-3 . Air is allowed to travel through the openings  84 , thereby improving bounce performance as described in each of the previous embodiments. An additional variation of the invention which functions in an identical manner would be an inflated toroidal tube having diameter which varies in a pattern alternating between a maximum and a minimum diameter, such that the areas having the minimum diameter provide an openings between the tube and the lower frame  80  of the trampoline. The openings thus created provide a means for air to bass between the interior and the exterior of the inflatable tube as previously described. 
         [0031]    An additional feature of the invention of  FIG. 1-3  is shown in  FIG. 9 . Inflation valves are commonly used in the art for both inflation and deflation of inflatable devices. A disadvantage of these devices is that they are manufactured of rigid plastic material which may become damaged when the device is impacted, or may cause injury to users when they come in direct contact with the valve. The air ducts  22  afford additional advantages of durability and safety with respect to said inflation valves. The perspective view through air duct  22  illustrates inflation valve cap  92  and inflation valve seat  90 . The valve is located on the wall  13  of the duct  22 , at the midpoint  15  through the toroidal tube. This location of the inflation valve within the air duct  22  is advantageous in preventing damage to the valve as a result of impact during use or transportation of the invention. In addition, because its location is removed from the areas of the device that users will conduct their activities, this valve location prevents bodily injury through inadvertent contact. 
         [0032]      FIG. 10  shows a cross sectional view of an alternative means of construction to those shown in  FIGS. 7A-D . The toroidal tube outer wall  90  has openings  94  for air duct  92 , which is defined by duct wall  98 . Duct wall  98  is supported by vertical walls  96 , which prevent the duct from collapsing inward under pressure from inflated chamber  100 . Note that vertical walls as viewed from above form concentric rings which are internal to toroidal tube outer wall  90 . 
         [0033]    Thus, the disadvantages of poor performance, poor durability, and poor safety seen in prior art water trampolines are corrected by the present invention through the use of the novel features previously described. 
         [0034]    While the invention has been described in connection with various preferred embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.