Abstract:
A method and apparatus for attaching a valve to another device such as a device, such as a device for separating a solid from a liquid. A valve seat according to the present invention is friction fitted into an orifice defined by the device and a conduit is attached to the valve seat via a removable spline.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/364,698, filed Mar. 15, 2002, entitled “Twist-Lok Valve Seat”, herein incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to pipe joints and couplings and, more particularly, to a valve seat for use with a sand classifying tank. 
     2. Brief Description of the Prior Art 
     A sand classifying tank is a piece of equipment which receives a sand and water slurry. As particles of sand flow through the sand classifying tank, coarse sand particles settle to a bottom portion of the tank, followed by finer sand particles. By combining sand particles from different sections at the bottom portion of the tank, it is possible to make different classifications of sand. 
     Sand particles exit a bottom portion of the sand classifying tank through a valve which meters the amount of sand exiting the sand classifying tank. In the past, the valves have been attached to the tank by some sort of fastener, such as bolts or a wedge arrangement. Because the fastener is in contact with the sand and water, the fasteners have a tendency to rust or gall. This often requires that the fasteners be cut from the bottom of the sand classifying tank when the valve is replaced. Moreover, some of the valves are often sealed with silicon or another waterproof sealant, further complicating the installation and removal process. 
     Therefore, a need exists for an apparatus and method for easily installing and removing a valve from a sand classifying tank. 
     SUMMARY OF THE INVENTION 
     The present invention provides a quick way for one person to remove a valve from a sand classifying tank without having to cut a rusted or galled fastener. Furthermore, the present invention provides a fast and easy method of connecting one body to another body via a flexible spline. More particularly, the present invention helps to reduce the amount of time required to replace a pipe connected to the valve seat. 
     The present invention includes a method to attach a valve seat to a device that is used to separate a solid from a liquid and attach a conduit to the valve seat. The valve seat has an interior surface which defines a first recess and an exterior surface which defines a spline orifice that is in fluid communication with the first recess. The conduit has a first end which defines a spline groove. The preferred method includes the steps of inserting the valve seat into an orifice defined by the device that is used to separate a solid from a liquid and rotating the valve seat in a first direction with respect to the device to removably lock the valve seat in place. Other steps include aligning the first recess defined by the interior surface of the valve seat with the groove defined by the first end of the conduit to form an aligned orifice and inserting a flexible spline through the spline orifice into the aligned orifice. The conduit is removed from the valve seat by removing the flexible spline via the spline orifice. The valve seat is removed from the body by rotating the valve seat in a second direction with respect to the body to unlock the valve seat from the body. 
     A valve seat according to one embodiment of the present invention may include a hollow body that defines an internal surface and an external surface, wherein the internal surface defines a first recess and a second recess spaced away from the first recess. The external surface defines a spline orifice which extends from the external surface of the hollow body to the second recess. The internal surface may further define a third recess spaced away from the first recess and the second recess and the external surface may define a slot that is configured to receive a tab of the device that separates a solid from a liquid. A first sealing member may be positioned in the first recess and a third sealing member may be positioned in the third recess. 
     A valve seat according to one embodiment of the present invention may include a hollow body which has a first end, a second end, and defines an internal surface and an external surface. The internal surface may define a throat generally positioned at the first end of the hollow body, a channel generally positioned at the second end of the hollow body and fluidly connected to the throat, an annular ridge positioned at an intersection of the throat and the channel, a first annular recess positioned in the channel between the throat and the second end of the hollow body, and a second annular recess positioned between the first annual recess and the second end of the hollow body. The external surface may define a spline orifice which extends from the external surface of the hollow body to the second annular recess. 
     The throat may define an annular throat wall and a tapered wall which opens in a direction toward the first end of the hollow body. The taper of the tapered wall may be approximately twenty-one degrees as measured from the annular throat wall. If a taper is included, it is preferred that a first diameter of taper at the first end of the hollow body is greater than a second diameter of the taper at a first intersection of the tapered wall and the annular throat wall. The channel preferably has a larger channel diameter than the first diameter of the annular throat wall, the first annular recess has a recess diameter which is greater than the channel diameter of the channel, and the second annular recess also has a recess diameter which is greater than the channel diameter of the channel. 
     The external surface has a cap and a cylinder portion, where the cylinder portion defines one or more slots adjacent to the second end of the hollow body. The cap is positioned adjacent to the first end of the hollow body, and the cap defines a plurality of cap tabs which extend away from the cap in a direction toward the second end of the hollow body. A cap seal may be positioned between the cylinder portion of the external surface of the hollow body and the cap tabs defined by the cap. 
     Each slot generally forms an L-shape defined by a trunk and an arm and the trunk preferably extends from the second end of the hollow body to the cap. The cap further defines a plurality of indentations which act as gripper surfaces to help aid in the installation or removal of the valve seat. 
     These and other advantages of the present invention will be clarified in the description of the preferred embodiment taken together with the attached drawings in which like reference numerals represent like elements throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a cross-sectional side view of a valve seat according to a first embodiment of the present invention; 
     FIG. 1B is a cross-sectional side view of a valve seat according to a second embodiment of the present invention; 
     FIG. 2 is a side view of the valve seat shown in FIG. 1A rotated 180 degrees; 
     FIG. 3 is a top perspective view of the valve seat shown in FIGS. 1A and 2; 
     FIG. 4 is another side view of the valve seat shown in FIGS. 1A,  2 , and  3 ; 
     FIG. 5 is a top end view of the valve seat shown in FIGS. 1A and 2; 
     FIG. 6 is a partial cross-sectional side view of a sand classifying tank; 
     FIG. 7 is a top view of a bottom portion of the sand classifying tank shown in FIG. 6; and 
     FIG. 8 is an exploded view of the valve seat shown in FIGS.  1 A and  2 - 5 , the bottom portion of the sand classifying tank shown in FIG. 7, and a pipe. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention can be used in any application where a valve is attached to a device and in any application where another object is attached to the valve after the valve has been installed on the device. 
     FIG. 1A shows a cross-sectional view of a valve seat  10  according to one embodiment of the present invention. The valve seat  10  is preferably injection molded from a polymer or other suitable material. The valve seat  10  preferably has a generally cylindrically-shaped hollow body  12  which has a first end  14 , a second end  16 , and defines an internal surface  18  and an external surface  20 . The internal surface  18  defines a throat  22  generally positioned at the first end  14  of the hollow body  12 , a channel  24  generally positioned at the second end  16  of the hollow body  12  and fluidly connected to the throat  22 , an annular ridge  26  positioned at an intersection of the throat  22  and the channel  24 , a first recess, such as first annular recess  28  positioned in the channel  24  between the throat  22  and the second end  16  of the hollow body  12 , and a second recess, such as second annular recess  30  positioned between the first annular recess  28  and the second end  16  of the hollow body  12 . A spline orifice  32  extends from the external surface  20  of the hollow body  12  to the second annular recess  30 . The first annular recess  28  may receive a sealing member as discussed below. 
     As shown in detail in FIG. 1A, the throat  22  preferably defines an annular throat wall  34  and a tapered wall  36  which opens in a direction toward the first end  14  of the hollow body  12 . A taper α of the tapered wall  36  is approximately twenty-one degrees as measured from the annular throat wall  34 , such that a first diameter D1 of taper at the first end  14  of the hollow body  12  is greater than a second diameter D2 of the taper at a first intersection  38  of the tapered wall  36  and the annular throat wall  34 . 
     With continuing reference to FIG. 1A, the channel  24  preferably has a larger channel diameter D3 than the first diameter D1 of the tapered wall  36 . In turn, the first annular recess  28  and the second annular recess  30  each have a recess diameter D4 which is greater than the channel diameter D3 of the channel  24 . 
     FIG. 1B shows a valve seat  10 A which is related to the valve seat  10  shown in FIG. 1A, with like reference numeral indicating like parts. However, the valve seat  10 A shown in FIG. 1B defines a third annular recess  31  which is preferably identical to the first annular recess  28 . The third recess, such as annular recess  31 , receives a third sealing member  69  (FIG. 10) as discussed below. The addition of the third annular recess  31  is necessary in some applications where a first sealing member  68  (FIG. 10) is positioned in the first annular recess  28  is pinched or is otherwise compromised during installation of a separate conduit, as discussed below. As also shown in FIG. 1B, one or more standard hose clamps HC may also be provided to help keep the separate conduit connected to the valve seat  10 A, or the valve seat  10  shown in FIG.  1 A. 
     FIGS. 2-4 best show the external surface  20  of the hollow body  12  of the valve seats  10  and  10 A. As shown in FIG. 2, the external surface  20  has a cap  40  and a cylinder portion  42 , where the cylinder portion  42  defines one or more slots  44  adjacent to the second end  16  of the hollow body  12 , and the cap  40  is positioned adjacent to the first end  14  of the hollow body  12 . The cap  40  defines a plurality of cap tabs  46  which extend away from the cap  40  in a direction toward the second end  16  of the hollow body  12 . A cap seal  48 , such as an elastomeric O-ring made from rubber, TEFLON or other suitable material, is positioned between the cylinder portion  42  of the external surface  20  of the hollow body  12  and the cap tabs  46  defined by the cap  40 . Each slot  44  generally forms an L-shape defined by a trunk  50  and an arm  52 . The trunk  50  preferably extends from the second end  16  of the hollow body  12  to the cap  40 , but this exact configuration is not required. 
     As shown in FIGS. 2 and 3, the arm  52  of each slot  44  generally extends away from the trunk  50  in a generally perpendicular direction. As best shown in FIG. 4, the arm  52  has a first width W1 at an intersection of the arm  52  and the trunk  50 , and a second width W2 at a terminal point  54  of the arm  52 . The functions of the trunk  50 , the arm  52 , and the first and second widths W1, W2 are discussed below. 
     As shown in FIG. 5, the cap  40  further defines a plurality of indentations  58  which act as gripper surfaces to help aid in the installation or removal of valve seats  10  and  10 A. 
     FIGS. 6-8 generally show a sand classifying tank  60 , which is used as a specific example of one type of device that separates solids from a liquid. Other suitable devices which separate solids from a liquid are also clearly contemplated. The arrow in FIG. 6 shows the flow direction of sand and water slurry into the sand classifying tank  60 . FIG. 8 shows a sand classifying tank  60  having a bottom portion  62  defining a plurality of orifices  64  which receive a corresponding valve seat  10 ,  10 A according to the present invention. As shown in FIG. 9, each orifice  64  further defines one or more tank tabs  66  which extend toward an imaginary center of each orifice  64 . Each tank tab  66  preferably has a tab width W3 less than or equal to a width W4 (FIG. 10) of each trunk  50 . 
     As shown in FIG. 10, each tank tab  66  preferably has a thickness T substantially equal to the second width W2 of each arm  52  of each slot  44 . The valve seats  10  or  10 A are each fitted with the cap seal  48 , discussed above, and a first sealing member, such as first annular sealing member  68 , is positioned in the first annular recess  28 . In the case of the valve seat  10 A shown in FIG. 1B, a third sealing member, such as third annular sealing member  69  (FIG. 10) is also positioned in the third annular recess  31 . The addition of a third annular sealing member  69  is optionally required in situations where a conduit has a leading edge which dislodges the first annular sealing member  68  installed in the first annular recess  28  during installation of the pipe  72 . The third annular sealing member helps to keep a fluid-tight seal between the pipe  72  and the valve seat  10 A. 
     With continuing reference to FIG. 10, a valve is installed in either of the valve seats  10 ,  10 A through the first end  14  of the hollow body  12 . The cylinder portion  42  of the hollow body  12  is then inserted into a corresponding orifice  64  in the bottom portion  62  of the sand classifying tank, such that each tank tab  66  is aligned in a corresponding trunk  50  of each slot  44 . The valve seat  10 ,  10 A is then pushed toward the bottom portion  62  of the sand classifying tank  60 , with the cap seal  48  providing an elastic force between the cap  40  of the hollow body  12  and the bottom portion  62  of the sand classifying tank  60 . Once each tank tab  66  is received in a corresponding trunk  50  and aligned with a corresponding arm  52 , the entire valve seat  10 ,  10 A is rotated about the imaginary axis I until each tank tab  66  firmly engages a corresponding arm  52 . The engagement, caused in part by the thickness of the tank tabs  66 , the gradually narrowing width W2 of each arm  52 , and in part by the elastomeric properties of the annular sloped seal  48 , keeps the valve seat  10 ,  10 A in place and helps to prevent unwanted reverse rotation of the valve seat  10 ,  10 A once the valve seat  10 ,  10 A is installed. The cap seal  48  also provides a watertight seal between the bottom portion  62  of the sand classifying tank and the valve seat  10 ,  10 A. 
     Once the valve seat  10 .  10 A according to either embodiment of the present invention is installed in the bottom portion  62  of the sand classifying tank and a conduit is connected to the valve seat  10 ,  10 A. When the conduit is a cylindrically-shaped pipe  72 , a first pipe end  70  of the pipe  72  can be inserted into the internal surface  18  of the hollow body  12  through the second end  16  of the hollow body  12 . The first pipe end  70  of the pipe  72  or other conduit defines a groove, such as an annular pipe groove  74 . The annular pipe groove is aligned with the second annular recess  30  defined by the internal surface  18  of the hollow body  12  to form an aligned orifice. A flexible spline  76 , made from an elastomeric material, such as rubber, TEFLON, or other suitable material, is inserted into the spline orifice  32  defined by the hollow body  12  and is fed into the aligned second annular recess  30  and the pipe groove  74 . Once the flexible spline  76  is fed completely through the aligned second annular recess  30  and the pipe groove  74 , the valve seat  10 ,  10 A and pipe  72  are removably connected to one another. 
     Removal of the valve seat  10  is easily accomplished by reverse rotation of the valve seat  10  with respect to the bottom portion  62  of the sand classifying tank  60 . Removal of the pipe  72  or other type of conduit is easily accomplished by removing the flexible spline  76  from the aligned second annular recess  30  and the pipe groove  74  and sliding the pipe  72  from the valve seat  10 ,  10 A. 
     The present invention provides a quick way for one person to remove a valve from a sand classifying tank  60  without having to cut a rusted or galled fastener. Furthermore, the present invention provides a fast and easy method for one person to connect one body to another body via a flexible spline. More particularly, the present invention helps to reduce the amount of time required to replace a pipe connected to a valve seat. 
     The invention has been described with reference to the preferred embodiment. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.