Abstract:
A diving stick of the type that, after being tossed into a swimming pool, sinks to the bottom while maintaining an upright posture so that it be can easily grasped by a diver. The stick includes a soft hollow shank designed to prevent accidental impalement. The stick also includes means for swapping components to vary the number of subsets of sticks within a set.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to a diving stick, and in particular to a set of diving stick with a body made of interchangeable colored end caps and soft and decorative fabric sleeves. 
     BACKGROUND AND OBJECTS OF THE INVENTION 
     A “diving stick”, or a “dive stick”, is an amusement device used in swimming pools. Such a stick will generally comprise a long thin buoyant body having a weight at one end that is sufficient to cause the body to sink in water and to stand upright, weight side down, on the bottom of a swimming pool. 
     Dive sticks are thrown into the water of a swimming pool, where they sink to the bottom and stand vertically on-end. During pay with these sticks in various games and exercises, several swimmers competing either individually against each other or as members of competing teams, dive into the pool and retrieve one or more sticks standing at the pool&#39;s bottom. Besides being a form of amusement, such games and exercises improve the abilities of the swimmers to hold their breaths, and improve their underwater swimming skills. 
     In one dive stick game, differing point values are assigned to each stick, and swimmers obtain a score according to the total value of the sticks they have retrieved. In another game, swimmers or teams are assigned individually sticks and obtain a score equal to the number of their sticks they have retrieved in a single dive. Several of the many other dive stick games are disclosed in U.S. Pat. No. 6,220,599. In many games, the ability for a diver to readily visually recognize the value or type of stick is critical to success in the game. 
     Originally, such sticks were rigid. Because certain of these long thin rigid sticks, when standing straight up from the pool bottom, posed an impalement risk to divers, the United States Consumer Products Safety Commission imposed a broad recall and subsequent ban of rigid dive sticks. Since that ban, only dive sticks that are flexible and/or malleable have been sold in the United States. According to the Final Rule of the Consumer Product Safety Commission (CPSC) as recited in the Federal Register on Mar. 7, 2001 (Volume 66, Number 45 at pages 13645-13652) “. . . dive sticks and similar articles that maintain a compressive force of less than 5-lbf under the test at Sec. 1500.86(a)(8) are exempt from this banning rule.” Flexible and malleable sticks such as those that are exempted are exemplified in U.S. Pat. Nos. 6,332,822 and 6,220,599. 
     However, such flexible and malleable sticks are still found to have certain disadvantages. Even though passing the 5-lbf compressive force test and posing less of a hazard, those sticks can still pose a certain hazard to a diving swimmer. While being somewhat softer than the original rigid dive sticks, such sticks as disclosed in the &#39;822 and &#39;599 patents are still relatively rigid in comparison to other swimming pool toys. For Instance, the diving sticks shown in FIGS. 1 through 3C and described at Column 3 Line 66 to Column 4 Line 44 of U.S. Pat. No. 6,332,822 employs a body made of polyvinyl chloride or “any material of similar properties of softness and malleability”. While such a softness and malleability may pass the current CPSC regulations, there remains in this inventor&#39;s opinion a significant likelihood of injury, or at least pain, should a swimmer impact an upstanding diving stick made of such a material during a dive. 
     And while the body of the diving stick embodiments shown in FIGS. 4 and 5 and described at Column 4 Line 45 to Column 5 Line 6 of that same &#39;822 patent may be made of a fabric, these bodies are filled with a soft stuffing material such as foam or polyfill or “any materials having properties of softness and pliability corresponding” thereto. While such a softness and pliability may pass the current CPSC regulations, there remains in this inventor&#39;s opinion a similarly significant likelihood of injury, or at least pain, should a swimmer impact an upstanding diving stick made of such a material during a dive. 
     Additionally, although they are somewhat bendable, such sticks as taught in the &#39;822 patent and elsewhere in the prior art must be packaged and stored in a straight shape or else they are prone to becoming permanently bent and disfigured. 
     And, such sticks are relatively expensive to manufacture. 
     It is therefore an object of the present invention to provide a diving stick which overcomes the above described drawbacks of the prior art and is safer, less expensive to manufacture, and less susceptible to damage by packaging. 
     Further, it is an object of the present invention to provide a set of diving sticks that more easily enable recognition between the sticks of the set by allowing using materials that offer greater ornamental flexibility, a wider range of color and decorative combinations, and easy interchangeability between the visible components. 
     Further, it is an object of the present invention to provide diving sticks whose opposite ends are more similarly shaped and weighted so that the sticks may be grasped at either end and still be properly balanced for throwing while still having the desired imbalance of buoyancy when in the water. 
     Additional benefits and objects will become apparent to those skilled in the art upon review of the following description of the present invention. 
     SUMMARY OF THE INVENTION 
     The drawbacks of the prior art are overcome and the objectives of the present invention are achieved by providing a diving stick made of similarly shaped and substantially similarly weighted end cap portions connected by a soft tubular fabric sleeve. 
     In the preferred embodiment, the present invention comprises a sleeve made of a decorative and resilient fabric material that is removably attached at both ends to polymeric spherical end cap portions, to form a long thin diving stick. 
     The dive stick is initially buoyant as it enters the water, but is adapted through the permeability of the fabric and through holes in the end cap portions to quickly intake water, whereby the sticks sink towards the pool bottom. 
     The end cap portions are similarly shaped and substantially similarly weighted to allow grasping at either end for balanced throwing, and externally visible surfaces of the end caps on a given stick are similarly colored to ease visual identification above or below the water. While the end cap portions at each end of the stick have substantially similar weights to ease throwing above the above the water, one end cap portion of each stick is more buoyant to cause the stick to stand upright when submerged in water as it arrives at the pool bottom. 
     The fabric sleeves of a set of diving sticks may be of different colors and have different decorative patterns to ease visual recognition while underwater. The fabric sleeves are easily interchangeable among sets of sticks to allow users to mix and match the decorative arrangements of the stick to more easily create sub-sets of team-owned or player-owned sticks. Such arrangements ease visual recognition of different sticks while above or under water. Additionally, a set of diving sticks may include sticks having end cap portions of different colors to ease visual recognition of different sticks while underwater. 
     The soft fabric sleeves may be folded or crumpled up for reduced volume during packaging, yet are able to retake their original tubular shape without damage or disfigurement upon unpacking. 
     The air-filled tubular fabric provides the softest and most pliable, and therefore safest, diving stick assembly yet invented to provide the least risk heretofore discovered for impalement or injury to users, while the weights and buoyancies of the end cap portions provide the requisite qualities for throwing and underwater use. 
     Further advantages and improvements are described in the following drawings and description of the preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view of a swimmer retrieving a dive stick according to the preferred embodiment of the present invention, 
         FIG. 2  is an exploded view of the dive stick of  FIG. 1 , and 
         FIG. 3  is a broken cross-sectional view through the dive stick of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As illustrated in  FIGS. 1 through 3 , the diving stick  100  of the preferred embodiment of the invention includes a tubular elongate body  102 , an upper end cap portion  104 , and a lower end cap portion  106 . Preferably, the sticks are sold in sets comprising an even number of sticks, one half of the number being decorated and/or colored differently than the other half, so that each half may be assigned to a different team of users when using the sticks in a team-competing game. 
     Tubular elongate body  102  comprises a soft, flexible and resilient fabric sleeve  112  that is 6¾ inches long and approximately ⅝ inches in diameter and preferably made of a porous cloth material. 
     The cloth is preferably a polyester knit material, chosen for its softness, its ability to be easily woven, painted or dyed with decorative patterns, its porosity and water permeability, and its resilience to recover its shape after long periods of folding or crumpling such as during packaging. Other “wrinkle-free” synthetic fabric materials, such as nylon or rayon, may be used in cases where the sticks will be folded or crumpled into a shipping package, or a natural fabric material, such as cotton may be acceptable such as in the case where the stick will be packaged in a flat and unwrinkled state, such as in a display pack. 
     The cloth is preferably painted, printed or woven with a decorative pattern or design on its external surface that is both bright and attractive. Preferably, a water-based non-lead paint is used to apply the pattern to the cloth prior to being formed into the sleeve, which paint and method of application are found to avoid blocking of the fabrics pores to thereby enhance permeability. Aside from their ornamental value, the patterns are intended to aid in visibility by swimmers searching for the sticks underwater, and to ease identification in comparison to sticks bearing different patterns or designs, so that for instance during team-competitive games, players can readily recognize the sticks that are “owned” by their team. As an example, one half of the sticks in a set might have a fine yellow pattern on a dominating red background while the other half may have a fine red print on a dominating yellow background. The terminal ends  114  of sleeve  112  are folded inwardly and sewn to form drawstring-retaining channels  116 , through which are inserted drawstrings  118 . 
     End caps  104  and  106  are molded of a plastic, preferably ABS, which is less dense than water, in a bright and decorative color that both compliments the coloring of sleeve  112  and eases visibility and identification of the sticks comparison to sticks bearing differently colored end caps. For instance the half of the sticks in the set that has the red sleeve background color may have yellow-colored end caps while the half that has the yellow sleeve background may have red-colored end caps, so that sticks of either half of the set are both readily visible to swimmers, and can be easily and quickly distinguished from the other sticks during play. 
     Both upper end cap  104  and lower end cap  106  comprise bulbous portion  122  and neck portion  124 . Bulbous portions  122  of both end caps are substantially identical in external diameter of approximately 1 3/16 inches and substantially spherical shape and are thereby adapted for comfortable grasping by the user, and to provide both balance for throwing and mass for sinking when the stick is thrown into the water of a swimming pool. Neck portions  124  both comprise a shaft  126  having a diameter of approximately ⅝ inch for inserting into one of the terminal ends  114  of sleeve  112  and a groove  128  thereon adapted to receive the tightened drawstring  118  after the shaft has been so inserted, to ensure that the end caps cannot inadvertently slip out of the sleeve during use of the stick. 
     Drawstring  118  is preferably tied in a knot after tightening to semi-permanently affix the end caps to the sleeve, however, it is one inventive aspect of this diving stick that the user may “mix and match body portions and end caps by untying and loosening the drawstrings and swapping end caps of one color into sleeves of another color. This enables an increase in the number of subsets of sticks for games wherein more than two teams are competing. For example, a first team may “own” sticks that have a dominantly red sleeve and yellow end caps, and a second team may “own” sticks that have a dominantly yellow sleeve and red end caps, while a third team may “own” sticks that have a dominantly red sleeve and red end caps, and a fourth team may “own” sticks that have a dominantly yellow sleeve and yellow end caps. All of these coloring arrangements are very visible, yet easily and instantly distinguishable, and all may be readily arranged for the two end cap color variations and two sleeve pattern variations provided in the stick set. 
     Lower end cap  106  further comprises ballast  132 , which is preferably made of a non-corrosive metal and which causes lower end cap  106  to be only insignificantly heavier than upper end cap  104  when above the water to thereby cause no significant imbalance during throwing, yet which causes lower end cap  106  to be substantially denser than upper end cap  104  so that the stick will always sink in the water with the lower end cap sinking first and pulling the stick  100  down in the water and the stick  100  will always come to rest with the lower end cap  106  on the pool bottom. 
     Initially as stick  100  is cast into the water, the hollow interior of the sleeve  112  is filled with air and the stick is positively buoyant and floats at the water surface  202 . Lower end cap  106  further comprises water intake channel  134 , which allows water to enter the hollow interior portion of the sleeve and the stick to thereby become negatively buoyant and gradually sink towards the bottom surface  200  of the pool. 
     Upper end cap  104  is only insignificantly less heavy than upper end cap  106  when above the water to thereby cause no significant imbalance during throwing. Upper end cap  104  comprises temporary air-holding cavity  136  which communicates to the outside of the stick through air escape channel  138  and permanent air-holding cavity  142 , which is adapted to hold just enough air to render the upper end cap slightly positively buoyant when the temporary air-holding cavity  136  has filled with water, but which does not hold enough air to render the entire stick positively buoyant even when temporary air-holding cavity  136  and the sleeve  112  have filled with water. 
     Regardless of the specific material used to make the end caps, it is an important aspect of the invention that upper end cap  104  is less dense than water and that lower end cap  106  is not only denser than water, but also heavy enough to overcome any positive buoyancy of the remainder of stick  100  as the stick becomes water-filled. This ensures that the stick  100  will be pulled to the floor  200  of the pool  208  by the weight of lower end cap  106 , and will assume a standing posture on the pool floor with lower end cap  106  on the pool floor and upper end cap  104  aiming upwardly and ready for grasping by a swimmer  206 . 
     The sinking process of stick  100  begins immediately after the stick is cast into the pool water, as water begins to enter the stick&#39;s interior through water intake channel  134  and sleeve  112 , and air begins to exit the stick through air escape channel  138 . This flow pattern of water only coming in through channel  134  and sleeve  112  and air escaping through channel  138  is caused by the tendency of denser lower end cap  106  to immediately start to sink while buoyant upper end cap  104  remains at the water surface  202 . As the sleeve becomes more and more water-filled, the stick begins to sink in the pool, with the lower end cap  106  sinking first. 
     Upper end cap  104  is substantially less dense than lower end cap  106 , particularly when first thrown into the water and temporary air-holding cavity  136  is filled with air, so that the stick will always sink in the water with the upper end cap raised towards the water surface  202 . And because the permanent air-holding cavity  142  renders the upper end cap slightly positively buoyant, the stick  100  will always come to rest with the upper end cap directed upwardly from the pool bottom and the stick  100  standing vertically as shown in  FIG. 1 . 
     Numerous games of play and exercises are well-known for use of diving sticks, generally requiring a swimmer  206  to dive into a swimming pool  208  and collect one of more sticks which have previously been cast into the water and which stand on the pool&#39;s bottom surface. It should be appreciated that the porosity of the fabric of sleeve  112  of sticks made according to the present invention provides a safety system for allowing the stick to be easily compressed when impacted under water. When so impacted, water flows rapidly out through the sleeve&#39;s fabric and this renders the stick far more easily and instantly compressible that sticks of the prior art, so that even if a diver is to impact an upstanding stick straight-on, he cannot be impaled and is far less likely to be injured. 
     It should also be appreciated that the foregoing is merely one of numerous possible embodiments of the present invention, is meant only to teach that embodiment currently preferred by the inventor, and is not intended to limit the scope of the invention in any way. Such limitations should be determined by the elements of the following claims, including equivalents thereto.