Abstract:
Disclosed herein is a childproof valve for a swimming pool. In one embodiment, the valve may include a valve body having an inlet and an outlet and a flow-passage extending therebetween, a plunger movable within the valve body between closed and open positions to either close or open the flow-passage, a tap mounted to the valve body, and a clutch device interposed between the tap and the plunger and co-operating with the tap such that rotation of the tap will not move the plunger unless the tap is first moved axially.

Description:
BACKGROUND  
         [0001]    Water in an above-ground swimming pool is recirculated by a pump for filtration. It is sometimes necessary to undertake maintenance on the filter or the pump. If the pump and filter are lower than the pool water level, it is advisable to close a valve in each of the draw pipe and return pipe prior to removal of the filter or the pump, to prevent unwanted drainage of the pool. Similarly, if the filter and pump are located higher than the pool water level, the valves should be closed to prevent drainage of the filter and pump, as many pumps can be damaged if they are run unprimed.  
           [0002]    To prevent such damage, close-off valves are commonly provided in the draw and return pipes connecting the pump and filter to the pool. It is important that these valves are not closed during operation of the pump, as the pump or the pipes themselves could be damaged by excessive back-pressure. However, above-ground swimming pools are often used by children, and inquisitive or naughty children might be tempted to play with the valve taps.  
         SUMMARY  
         [0003]    Disclosed herein a is childproof valve for a swimming pool. As used herein, the word “childproof” is intended to convey the idea of presenting difficulty to a child, not necessarily absolute prevention.  
           [0004]    In one exemplary embodiment, the childproof valve may comprise a valve body having an inlet and an outlet and a flow-passage extending therebetween, a plunger movable within the valve body between closed and open positions wherein the flow-passage is either closed or opened thereby, a tap mounted to the valve body, and a clutch device interposed between the tap and the plunger, the clutch device co-operating with the tap such that upon axial displacement of the tap, rotational motion of the tap is selectively converted to axial motion of the plunger between the closed position and the open position.  
           [0005]    In another exemplary embodiment, the plunger may be substantially cylindrical and may comprise a thread to effect axial movement of the plunger upon rotation thereof by the clutch device.  
           [0006]    In another exemplary embodiment, the plunger may be situated within an elbow of the valve body.  
           [0007]    In another exemplary embodiment, there may be an intermediate member co-operating with the clutch device and being substantially cylindrical and comprising thread co-operating with the thread of the plunger.  
           [0008]    In another exemplary embodiment, the clutch device may comprise a plurality of radially extending arms and the intermediate member comprises a plurality of radially extending slots into which the arms can be received. Alternatively the intermediate member comprises a plurality of radially extending arms and the clutch device comprises a plurality of radially extending slots into which the arms can be received.  
           [0009]    In another exemplary embodiment, the clutch device may comprise a non-circular shaft to which the tap is attached.  
           [0010]    In another exemplary embodiment, safety screen may be attached to the pipe.  
           [0011]    In still another exemplary embodiment, the childproof valve may comprise a pipe having an inlet and an outlet; a plunger within the pipe, the plunger having a plunger thread and being movable between an open position and a closed position such that when the plunger is in the open position, water may flow through the pipe, and when the plunger is in the closed position, water flow through the pipe is blocked; an intermediate member having an intermediate member groove co-operating with the plunger thread; a tap mounted to the pipe; and a clutch plate, interposed between the tap and the intermediate member, having a shaft, wherein axial pressure on the tap causes the tap to engage the clutch plate via the shaft, causing the clutch plate to engage the intermediate member. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0012]    These and other features and advantages of the childproof valves disclosed herein will be more fully understood by reference to the following detailed description, in conjunction with the attached drawings in which like reference numerals refer to like elements through the different views. The drawings illustrate principles of the apparatus disclosed herein, and are not to scale.  
         [0013]    [0013]FIG. 1 is a schematic cross-sectional elevational view of an exemplary valve unit, shown with the valve closed;  
         [0014]    [0014]FIG. 2 is a schematic cross-sectional elevational view of a clutch;  
         [0015]    [0015]FIG. 3 is a schematic plan view of the clutch of FIG. 2;  
         [0016]    [0016]FIG. 4 is a schematic elevational view of an intermediate member;  
         [0017]    [0017]FIG. 5 is a schematic inverted plan view of the intermediate member of FIG. 4;  
         [0018]    [0018]FIG. 6 is a schematic plan view of a tap; and  
         [0019]    [0019]FIG. 7 is a schematic perspective illustration of the tap. 
     
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS  
       [0020]    To provide an overall understanding, certain illustrative embodiments will now be described; however, it will be understood by one of ordinary skill in the art that the devices and methods described herein can be adapted and modified to provide devices and methods for other suitable applications and that other additions and modifications can be made without departing from the scope of the systems described herein.  
         [0021]    Unless otherwise specified, the illustrated embodiments can be understood as providing exemplary features of varying detail of certain embodiments, and therefore, unless otherwise specified, features, components, modules, and/or aspects of the illustrations can be otherwise combined, specified, interchanged, and/or rearranged without departing from the disclosed devices or methods. Additionally, the shapes and sizes of components are also exemplary, and unless otherwise specified, can be altered without affecting the disclosed devices or methods.  
         [0022]    In the accompanying drawings there is schematically depicted a valve  10 , with parts typically fabricated from PVC plastics material. However, the parts could be brass, stainless steel, HDPE or any other suitable material known in the art of swimming pool plumbing fixtures.  
         [0023]    Referring now to FIG. 1, the valve  10  comprises an elbow-shaped valve body  15  which may comprise extensions of circular cross-section. Attached to and inlet side of the valve body  15  is a pipe  12  that is externally threaded to receive a safety cage  11 . Safety cage  11  may be positioned on the inside surface of a swimming pool wall. To this end, there may be provided a collar  13  having internal thread engaging with external thread on a narrower portion  6  of the pipe  12 . The narrower portion  6  of the pipe  12  may pass through a hole in the swimming pool wall (not shown). The collar  13  may be tightened toward a shoulder  7  of the pipe  12 , pinching the pool wall between the collar  13  and the shoulder  7 , and securing the pipe  12  in place. There may be a retaining ring  14  through which any overhanging pool-lining material might pass.  
         [0024]    The valve body  15  may include a port  21  from which a pipe may extend to a pump. The interior of port  21  and the interior of pipe  12  form a flow-passage that is (in the configuration depicted in FIG. 1) closed by a valve plunger  16 .  
         [0025]    In the illustrated embodiment, the plunger  16  is cylindrical, fitting smoothly within the valve body  15 , and has a sealing ring  6  to seal against the inside surface of the valve body  15 . The valve plunger  16  may include inwardly projecting thread  17 , which in some embodiments may be a high pitch thread. In an exemplary embodiment, the thread  17  projects into the hollow interior of the valve plunger  16  as shown in the cutaway view of FIG. 1.  
         [0026]    Extending from the valve plunger  16  is an approximately cylindrical intermediate member  9 . The intermediate member  9  has a thread groove  8  to co-operate with the interior thread  17  of the valve plunger  16 , as shown in FIGS. 1 and 4. In the illustrated embodiment, the intermediate member  9  may include a cowling  24  that surrounds a clutch plate  18 . As shown in FIG. 5, there may be radially extending slots  25  formed in the underside of the intermediate member. Axial motion of the intermediate member  9  is restrained b a cap  20  and a shoulder  29  in the pipe  15 . The intermediate member  9  is free to rotate, however, and upon rotation imparts axial translational motion to the plunger  16 , via the cooperation of the thread groove  8  and the plunger internal thread  17 . For example, the threads may be oriented so that right handed rotation of the intermediate member  9  advances the plunger  16 , while left handed rotation causes the plunger  16  to retreat, or vice versa.  
         [0027]    The clutch plate  18  may include a shaft  23  which may be of non-circular hollow cross-section. In the embodiment illustrated in FIG. 2, the cross-section of the shaft  23  is square. There is a screw hole  27  at the end of the shaft through which a screw can extend downwardly into a pre-formed hole  5  in a tap  19 . The tap  19  is illustrated schematically in FIGS. 6 and 7. In an alternate embodiment, the shaft  23  may be integral with the tap  19  instead of with the clutch plate  18 . In such an embodiment, there may be a screw hole at the end of the shaft through which a screw can extend upwardly into a pre-formed hole  5  in the clutch plate.  
         [0028]    The clutch plate  18  is free to move vertically within the downwardly depending end portion of the valve body  15 , but is constrained by a cap  20 . In some embodiments, the cap  20  is threaded onto the valve body  15  as shown in FIG. 1. Alternatively, the cap may be affixed to the valve body via press fit, screws, bolts, or other suitable means.  
         [0029]    In the position depicted in FIG. 1, an upward force F must be applied to the tap  19  so that the clutch plate  18  engages with the intermediate member  9 . However, when the force F is not applied, gravity draws the tap  19  and the clutch plate  18  downwardly against the cap  20  to disengage the radial arms  22  from the radial slots  25 . In such a position, rotation of the tap  19  and therefore the clutch  18 , will not rotate the intermediate member  9 .  
         [0030]    When it is desired to open or close the valve, applying an upward force F on the tap  19  allows the clutch plate  18  to engage the intermediate member  9 . Turning the tap  19  while the clutch plate  18  is so engaged rotates the intermediate member  9 . This rotational motion of the intermediate member  9  is converted to axial translational motion of the valve plunger  16  as described above. In this manner, the arrangement of the tap  19  and clutch plate  18  may, upon axial displacement of the tap, selectively convert rotational motion of the tap to axial motion of the plunger between the closed position and the open position.  
         [0031]    In some embodiments, a feature such as a key-way may be provided on the external surface of the plunger  16  and the internal surface of the valve body  15  to prevent rotation of the plunger.  
         [0032]    To enable the device to be used in other orientations wherein the tap  19  does not necessarily extend downwardly, a spring might be provided between the clutch plate  18  and the intermediate member  9  to bias the clutch plate away therefrom.  
         [0033]    In addition to swimming pools, the valve disclosed herein can be used with spa pools, spa baths, or other applications requiring water-filtration or childproof valve.