Abstract:
An apparatus and method to attach a sand tank discharge elbow to a valve in a sand classification tank using a removable spline and an optional hose clamp.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Serial No. 60/365,377, filed Mar. 15, 2002, entitled “Sand Tank Discharge Elbow”, herein incorporated by reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention generally relates to pipe joints and couplings and, more particularly, to a discharge elbow for use with a sand classifying tank.  
           [0004]    2. Brief Description of the Prior Art  
           [0005]    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.  
           [0006]    Sand particles exit a bottom portion of the sand classifying tank through a valve which meters the amount of exiting sand particles. The sand continues through a pipe attached to the valve and exits through a discharge elbow fluidly attached to the pipe.  
           [0007]    Known discharge elbows are attached to the pipe by a bolted flange connection or a clamp assembly. When sand abrasion causes the discharge elbow to wear, the bolted flange connection or clamp assembly must be removed. Rust and corrosion makes the process of removing the bolted flange connection or clamp assembly more difficult. The process is further hampered because it is difficult to rotate the discharge elbow with respect to the pipe with the rusted and corroded bolted flange or clamp assembly partially fused to the discharge elbow.  
           [0008]    Therefore, a need exists for an apparatus and method for easily installing and removing a sand classification tank discharge elbow.  
         SUMMARY OF THE INVENTION  
         [0009]    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 provides a quick way of removing a discharge elbow from a pipe in a sand classifying tank without having to cut a rusted or corroded bolted flange.  
           [0010]    A discharge elbow according to one embodiment of the present invention generally includes a hollow body which has a first end, a second end, and defines an interior surface and an exterior surface. The interior surface defines a pipe receiving recess positioned adjacent to the first end of the hollow body, an annular spline receiving recess having a first width positioned in the pipe receiving recess, and a fluid conduit portion extending between the pipe receiving recess and the second end of the hollow body. The exterior surface defines a spline receiving orifice in fluid connection with the annular flange receiving recess defined by the interior surface of the hollow body. Stiffening fins may be added to the exterior surface of the hollow body. The hollow body may generally form a curved shape, and the hollow body may be formed from an injected molded polymer.  
           [0011]    The first embodiment discharge elbow may be added to a sand classifying tank having a bottom portion defining a plurality of orifices which receive a corresponding valve, a pipe having a first pipe end and a second pipe end connected to the valve via the first pipe end. More specifically, the discharge elbow is preferably connected to the second pipe end of the pipe, wherein the second pipe end preferably defines an annular pipe recess having a second width approximately equal to the first width of the annular flange receiving recess defined by the interior surface of the hollow body of the discharge elbow.  
           [0012]    One method of installing the first embodiment discharge elbow onto a pipe having a first pipe end and a second pipe end, wherein the second pipe end defines an annular pipe recess having a second width approximately equal to the first width of the annular flange receiving recess defined by the interior surface of the hollow body of the discharge elbow, may include the steps of (a) positioning the second pipe end of the pipe in the pipe receiving recess defined by the second end of the pipe, (b) aligning the annular spline receiving recess with the annular pipe recess, (c) inserting a flexible spline into the spline receiving orifice, and (d) feeding the flexible spline through the aligned combination of the annular spline receiving recess and the annular pipe recess to mate the pipe and the discharge elbow together.  
           [0013]    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  
       [0014]    [0014]FIG. 1 is a front view of a discharge elbow according to a first embodiment of the present invention;  
         [0015]    [0015]FIG. 2 is a side view of the discharge elbow shown in FIG. 1;  
         [0016]    [0016]FIG. 3 is a side view of a sand classifying tank; and  
         [0017]    [0017]FIG. 4 is an exploded view of a bottom portion of the sand classifying tank shown in FIG. 3, a pipe, and the discharge elbow shown in FIGS. 1 and 2. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]    The present invention generally contemplates using a discharge elbow in a sand classifying tank. However, the invention is not limited to this specific application.  
         [0019]    A discharge elbow  10  according to a first embodiment of the present invention includes a hollow body  12  which has a first end  14 , a second end  16 , and defines an interior surface  18  and an exterior surface  20 . The interior surface  18  defines a pipe receiving recess  22  positioned adjacent to the first end  14  of the hollow body  12 , an annular spline receiving recess  24  having a first width W1 positioned in the pipe receiving recess  22 , and a fluid conduit portion  26  extending between the pipe receiving recess  22  and the second end  16  of the hollow body  12 . The exterior surface  20  defines a spline receiving orifice  26  in fluid connection with the annular spline receiving recess  24  defined by the interior surface  18  of the hollow body  12 . One or more stiffening fins  30  may also be added to the exterior surface  20  of the hollow body  12  to provide strength to the hollow body  12 . A recess  25  can be included at the first end  14  to receive a standard hose clamp  50  (FIG. 2).  
         [0020]    As shown in FIG. 2, the hollow body  12  and the stiffening fins  30  generally form a curved shape. Moreover, the hollow body  12  and stiffening fins  30  are preferably made from injected molded polymer or other suitable material.  
         [0021]    [0021]FIG. 3 generally shows a sand classifying tank  32 . The sand classifying tank  32  generally has a bottom portion  34  defining a plurality of orifices  36  which each receive a corresponding metering valve  38 . A pipe  40  having a first pipe end  42  and a second pipe end  44  is connected to the metering valve  38  via the first pipe end  42 . The discharge elbow  10  is attached to the second pipe end  44  of the pipe  40 .  
         [0022]    As shown in FIG. 4, the second pipe end  44  defines an annular pipe recess  46  having a second width W2 approximately equal to the first width W1 of the annular flange receiving recess  24  defined by the interior surface  18  of the hollow body  12 .  
         [0023]    With continuing reference to FIG. 4, one method of installing the discharge elbow  10  includes positioning the second pipe end  44  of the pipe  40  in the pipe receiving recess  22  defined by the first end  14  of the hollow body  12 . The next step is aligning the annular spline receiving recess  24  defined by the interior surface of the hollow body  12  with the annular pipe recess  46 . Next, a flexible spline  48  is inserted into the spline receiving orifice  28  defined by the hollow body  12  and fed through the aligned combination of the annular spline receiving recess  24  and the annular pipe recess  46 . With the flexible spline  48  properly installed, the pipe  40  and the discharge elbow  10  are mated together and the standard hose clamp  50  can be clamped around the first end  14  of the hollow body, preferably using recess  25 . Removal of the discharge elbow  10  is easily accomplished by removing the optional hose clamp  50  and removing the flexible spline  48  from the aligned annular spline receiving recess  24  and the annular pipe recess  46  via the spline receiving orifice  28 .  
         [0024]    In summation, the present invention allows quick and convenient replacement of a discharge elbow. The flexible spline can be easily inserted or removed without a need for cutting rusted or corroded parts.  
         [0025]    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.