Patent Publication Number: US-7708012-B2

Title: Dry top snorkel having a locking device to prevent inadvertant closure

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to the field of snorkels and more specifically to an improved dry top for snorkels. 
   2. Background Art 
   This invention is an improvement of the snorkel dry top disclosed in issued U.S. Pat. No. 6,994,085 to Chih-Cheng Shiue and assigned to the assignee hereof. Snorkel dry tops comprise devices configured to prevent water from entering the open top of a snorkel tube. Typically they include a rubber-like diaphragm and a float or buoyant device. The diaphragm is positioned in proximity to the top opening for relative movement thereto for opening and closing the opening. Movement of the diaphragm is controlled by the float and its response to whether the water level is sufficiently high on the snorkel to make the float buoyant. When the float is immersed, its buoyancy forces it toward the top opening thereby forcing the diaphragm to close the opening and prevent the entry of water into the snorkel tube. When the float is above the water, gravity forces the float away from the opening, pulling the diaphragm from the opening as well and thereby allowing air to pass freely into and out of the snorkel tube. Some such snorkel dry tops also provide splashguards to resist entry of water droplets while the snorkel top is above the water surface and the diaphragm is pulled away from the opening. Such droplets of water come from splashing waves and the like and can otherwise enter the open top even while the top of the snorkel is above the water surface. One such snorkel dry top is described in U.S. Pat. No. 6,994,085 and includes both a diaphragm and float assembly as well as a splashguard referred to therein as a mask. Other such dry tops are disclosed in issued U.S. Patents such as U.S. Pat. No. 5,960,791 to Winefordner et al and U.S. Pat. Nos. 6,904,910 and 7,077,127 to Christianson. 
   An inherent problem associated with snorkel dry tops that depend on a combination of buoyancy and gravity is that they&#39;re subject to inappropriate operation when they&#39;re tilted above the surface. When they&#39;re above the surface, gravity should keep the tube top open so that air can pass freely into and out of the snorkel. However, if the top is tilted, the effect of gravity can inadvertently close the opening by forcing the diaphragm against the opening, thereby preventing the free-flow of air into and out of the snorkel tube. Even a rather modest tilting of the snorkel combined with a suction effect of air rushing into the opening while the snorkeler is breathing in, can inadvertently close the opening at an inappropriate time and thereby interfere with normal operation of the snorkel. 
   Therefore, there is a need to improve such dry top snorkels by configuring them so that they are more likely to stay open while they&#39;re above the water surface even when they are tilted. 
   SUMMARY OF THE INVENTION 
   The present invention is designed to provide the aforementioned improvement. More specifically, the improved snorkel dry top of the present invention has a fulcrum to which a float member and a diaphragm yoke are attached. The fulcrum has a blocking tab that rests in an aperture in the float member attaching hook when the snorkel is above the surface of the surrounding water. The diaphragm yoke cannot rotate the diaphragm when the blocking tab is in the hook aperture. Therefore, even when tilted, the snorkel uses a unique locking device to remain open allowing free flow of air into the snorkel tube. 
   Another significant improvement of the preferred embodiment of the present invention is the connection of the float member, diaphragm and yoke to the snorkel top&#39;s splashguard mask. This improvement assures that the delicate structures of these components are not exposed to potentially destructive impact forces in the event that the splashguard mask is removed from the snorkel tube. In the improved snorkel dry top of the present invention, when the snorkeler removes the splashguard mask, he or she also removes the float member, diaphragm and yoke at the same time so that the remaining snorkel can be used without a dry top. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The aforementioned objects and advantages of the present invention, as well as additional objects and advantages thereof, will be more fully understood herein after as a result of a detailed description of a preferred embodiment when taken in conjunction with the following drawings in which: 
       FIG. 1  is a view of a fully assembled snorkel having the improved dry top of the present invention; 
       FIG. 2  is an enlarged view of the dry top of the snorkel of  FIG. 1 ; 
       FIG. 3  is an exploded view with the splashguard mask shown in phantom to enable a clearer view of the diaphragm and float member of the preferred embodiment; 
       FIG. 4  is a side view of the diaphragm, yoke and float member; 
       FIG. 4A  is a view of the diaphragm and yoke taken along  4 A of  FIG. 4 ; 
       FIG. 4B  is a view of the float member taken along  4 B of the  FIG. 4 ; 
       FIG. 5  is an enlarged view of the yoke and float member interface shown while the float member is subjected primarily to buoyancy forces; 
       FIG. 6  is an enlarged view similar to that of  FIG. 5 , but shown while the float member is subjected primarily to gravity; 
       FIG. 7  is a side partially cross-sectioned view of the improved dry top shown oriented straight up; 
       FIG. 8  is a view similar to that of  FIG. 7 , but showing the improved dry top shown tilted about 15° from vertical; 
       FIG. 9  is a view similar to that of  FIG. 7 , but showing the improved dry top tilted about 45° from vertical; and 
       FIG. 10  is a plan view of the splashguard mask interior showing the connected diaphragm, yoke and float member. 
   

   DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
   Referring to the accompanying drawings, it will be seen that the preferred embodiment of a snorkel  10  in accordance with the principal features of the present invention, comprises a main tube  12 , a flexible portion  14 , a mouthpiece section  16  and a dry top  20 . Mouthpiece section  16  provides a mouthpiece  18  to enable a snorkeler to breath through snorkel  10  as long as the dry top  20  is above the water surface. A dive mask hook  24  allows the snorkel  10  to be secured to a dive or swim mask strap (not shown) as is typical for snorkels. The dry top  20  provides a splashguard  22  which, as will be seen hereinafter, serves the dual functions of resisting entry of splashed water into the top opening of the snorkel and providing a protective connection to critical components of the dry top  20 . 
   As seen best in  FIGS. 2 and 3 , the dry top  20  including splashguard  22  comprises a diaphragm  30 , a yoke  38  and a float member  32 , all of which are interconnected at a fulcrum  37 . Diaphragm  30 , held by yoke  38 , is designed to rotate with fulcrum  37  to open and close airflow opening  28  at the end of top tube  26 . Fulcrum  37  is controlled by the position of float member  32  depending upon whether the float member is above or below the water surface. If it&#39;s above the water surface, gravity causes the float member weight to pull down on the yoke  37  and pull the diaphragm  30  away from opening  28 . If it&#39;s below the water surface, the buoyancy effect of the water on the float member causes the float member to push up on the yoke and push the diaphragm against the opening. The yoke is elevated through its side members  34  and its axles  39  which are rotatably connected into receptacles  31  of guard  22 . The yoke  38  is permanently affixed to the fulcrum  37  while the float member  32  is merely hooked onto the fulcrum  37  so that the float member is free to swing in a limited fashion about the fulcrum. 
   As also shown in  FIGS. 2 and 3 , splashguard  22  is configured to releasably mate with the remaining structure of dry top  20 . Each side of guard  22  has a pair of receptacles  27  and  29  configured to receive corresponding cylindrical tabs  35  and  36  extending from each side of top tube  26 . In addition, the top of guard  22  has a receptacle  21  designed to receive an extending tab  23  above opening  28  on top tube  26  to firmly attach splashguard  22  in the manner shown in  FIG. 2 . A plurality of louvers  25  permit air to pass through guard  22  on its path through opening  28 . 
   Referring now to  FIGS. 4 ,  4 A,  4 B,  5  and  6 , it will be seen that the diaphragm yoke  38  comprises a pair of arches  40  attached at two spaced apart locations along fulcrum  37 . At the center of fulcrum  37  and between arches  40 , resides a blocking tab  42  extending upwardly therefrom. It will also be seen that extending from the top surface  33  of float member  32  is a hook member  44  having an aperture  46  at the uppermost portion thereof. Aperture  46  has an appropriate shape and size to receive blocking tab  42 . When the floating member  32  is buoyant, hook member  44  and blocking tab  42  are disengaged so that diaphragm yoke  38  is free to rotate diaphragm  30  into sealing engagement with opening  28 . However, when floating member  32  is not buoyant (i.e., out of the water) hook member  44  engages blocking tab  42  which is then trapped in aperture  46 . As shown in  FIGS. 7-9 , because of the proximity of the float member to the interior surface of the splashguard, it cannot rotate more than a few degrees before contacting that interior surface. Therefore, while blocking tab  42  is trapped in aperture  46 , the diaphragm also cannot rotate more than a few degrees before the float member hits the splashguard interior surface. Thus, when the dry top  20  is out of water (i.e., above the water surface) any extent of tilting of snorkel  10  will not permit diaphragm  30  to close the opening  28 . Even the 45° tilt shown in  FIG. 9  will not produce a closure of the snorkel dry top while it is above the water surface. Therefore, a significant disadvantage of the prior art is overcome by the locking device shown herein. 
   Another improvement of the dry top of the present invention is depicted in  FIG. 10 . More specifically, as shown in  FIG. 10 , the crucial components of the dry top (i.e., float member, diaphragm, yoke, fulcrum) are connected to the splashguard  22  and not to the top tube  26 . This equates to a form of protection of those critical components whenever the splashguard is removed. Therefore, unlike the prior art, there&#39;s no easy way to remove the splashguard and gain access to the float member and diaphragm while they&#39;re still configured for functional operation in conjunction with the snorkel top tube. 
   Having therefore disclosed improvements to prior art dry top snorkels, it will now be apparent that various modifications and additions may be made to the described embodiment without deviating from the inventive features of such improvements. Accordingly, the scope hereof is not to be deemed to be limited by the disclosed embodiment, but only by the appended claims and their equivalents.