Abstract:
A pump riser provided with recesses positioned and configured to receive and frictionally engage the legs of a septic system pump. The riser may support the pump above a support surface such as the bottom of the tank of a septic system. The riser body may include legs for supporting the riser body. The lower surface of a pump body may be supported above the upper surface of the riser body as the result of engagement between legs of a pump and the recesses.

Description:
TECHNICAL FIELD 
     The present method and apparatus relate to the field of supports for pumps. 
     BACKGROUND 
     One method of treating waste water is by use of a septic system. The prior art septic system shown in  FIG. 1  may include a tank  10  that may comprise a single chamber  11 . The tank may be capped with a lid  12  that has at least one access port  13  formed in it. The access port or ports  13  may be located proximate to an end of the lid  12  or may be centered in the lid  12  as desired. In  FIG. 1 , the access port  13  is shown as located adjacent one end of the lid  12 . The tank  10  may be buried in the ground  14 . 
     Access to the septic tank  10  may be available through a septic tank cover  16  which may allow access to the septic tank through a conduit or septic tank riser  17  that may be mated to the access port  13  in the lid  12  of the septic tank  10 . 
     Two kinds of septic systems are currently in use: in one, the effluent flows out of the tank  10  under the influence of gravity. Alternatively, as shown in  FIG. 1 , an electric pump  18  is used to pump the effluent up the discharge pipe  19  and out into the drain field (not shown). 
     As building codes and the like may require that the pump  18  be elevated above the bottom of the tank  10 , the current practice is to position a concrete paver or block  21  having a thickness, in some cases, of 4 inches (10 cm) or greater on the bottom of the tank  10 , and position the pump  18  on top of the block  21 . Unfortunately, the the block  21  is frequently mispositioned in the tank  10 , and correcting the positioning of the block  21  from the surface through the septic tank riser  17  can be difficult or impossible. If one or more of the legs of the pump are not seated on the paver or block  21 , the torque of the pump  18  starting up and shutting down may apply a tortional force to the discharge pipe  19  that may ultimately lead to its structural failure. 
     In addition, particulate matter may settle in the tank to form a layer of sludge  22 , the upper surface of which slopes generally up and away from the location of the pump  18 . When excessive sludge has accumulated, it may be necessary to pump the tank  10  out. 
     SUMMARY 
     A pump riser may be used to elevate a pump  18  above the bottom of a septic tank  10  or other support surface. Such a riser may frictionally engage the legs of a pump  18  to facilitate installation and removal. Legs of varying lengths may be provided or fabricated for the pump riser to adjust the height of the pump  18  above the support surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional schematic view of a prior art septic tank system buried in the ground. 
         FIG. 2  is an isometric view of a pump mounted on a pump riser, with an outlet pipe shown in phantom. 
         FIG. 3  is an isometric view of a pump riser. 
         FIG. 4  is a sectional view of the pump riser of  FIG. 3 . 
         FIG. 5  is a top plan view of the pump riser of  FIG. 3 . 
         FIG. 6  is a side elevation of the pump riser of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIG. 2  many pumps  18  useable in septic systems may be formed with three generally-frustoconical legs  26  disposed about, and depending from, the housing  27  of the pump  18 . In one embodiment, the pump  18  may also include an inlet (not shown) at the bottom of the pump housing  27  through which effluent may be drawn, and an outlet  28  at one side of the pump that may be attached to an outlet pipe  29  (shown in phantom) such as the discharge pipe  19  shown in  FIG. 1 . 
     In one embodiment, a pump  18  may be mounted on a pump riser  31  to support the inlet of the pump  18  above the bottom of a septic tank  10 , or paver or block  21 . The riser  31  may be made of any of a variety of materials, including polymeric materials such as PVC (polyvinylchloride) or ABS (acrylonitrile-butadiene-styrene) plastics. Referring to  FIGS. 2 and 3 , a pump riser  31  may comprise a body  32 . Recesses  33 , such as the cylindrical recesses  33  in the upper surface  34  of the pump riser  31 , may be formed in the upper surface  34  of the body  32  of the riser  31  and may be spaced so that they are coaxial with the legs  26  of a pump  18 . The dimensions of the cylindrical recesses  33  may be chosen such that the legs  26  of the pump  18  are constrained from extending completely down into the recesses  33 , and so that the legs  26  of the pump  18  frictionally engage a wall or walls of the recess  33 . In one embodiment, the legs  26  of the pump may be frustoconical and the recesses  33  may be cylindrical. Other configurations of leg  26  and recess  33  shape and size may be chosen in other embodiments. Fasteners, clamps or the like might also be used to secure the pump  18  to the body  32  of the pump riser  31 , but this would add to the complexity of the riser  31 . The diameter of the recesses  33  may be such that the outer surfaces of the legs  26  engage the inner surface of the recesses  33  after a certain percentage, which may be 50%, of the length of each of the legs  26  has entered the recess  33 . In such an embodiment, the lower surface of the pump  18  may be supported above the level of the upper surface  34  of the pump riser  31 , providing a gap through which effluent may flow toward the inlet of the pump  18 . 
     In one embodiment, the engagement of the outer surface of the frustoconical legs  26  and the inner surface of the recesses  33  may be pushed into contact sufficient that the pump  18  and the pump riser  31  have a sufficient frictional engagement that lifting the pump  18  results in the riser  31  being lifted along with it. 
     Referring to  FIGS. 2-6 , in an embodiment intended for use with a pump  18  that has three frustoconical legs, a pump riser  31  may be generally triangular in shape when viewed from above. Each of the sides  36  of the riser  31  may be generally planar and of equal height along its length. In one embodiment, a series of vents  37  may be provided. These vents  37  may be vertically oriented and spaced apart from one another along the length of the sides  37 . The upper ends  38  of the vcnts  37  vents  36  may be located at a position below the upper surface  34  of the pump riser  31 , and may extend downward toward the lower edge  39  of the sides  36 . The riser  31  may be provided with a shelf  41  that extends horizontally inward of the body  32  of the riser  31  at its lower edge  39 . In such case, the vents  37  may extend around the lower edge  39  of the riser  31  and extend across a portion of the shelf  41 . 
     Referring to  FIGS. 2-6 , in an embodiment intended for use with a pump  18  that has three frustoconical legs, a pump riser  31  may be generally triangular in shape when viewed from above. Each of the sides  36  of the riser  31  may be generally planar and of equal height along its length. In one embodiment, a series of vents  37  may be provided. These vents  37  may be vertically oriented and spaced apart from one another along the length of the sides  37 . The upper ends  38  of the vents  36  may be located at a position below the upper surface  34  of the pump riser  31 , and may extend downward toward the lower edge  39  of the sides  36 . The riser  31  may be provided with a shelf  41  that extends horizontally inward of the body  32  of the riser  31  at its lower edge  39 . In such case, the vents  37  may extend around the lower edge  39  of the riser  31  and extend across a portion of the shelf  41 . 
     The vents  37  may have a width selected to restrict the flow of larger particulates into the pump  18  while still allowing the flow of effluent through them. In one embodiment, the width of the vents  37  may be selected as ¼ inches (0.64 cm). This may be varied according to the size of the particles intended to be blocked by the vents  37 . Such particles may comprise organic material such as clumps of tissue paper or inorganic material such as small pebbles. As is known in the art, such large particulates in effluent fed to a drain field may compromise the drain field. Such filtering may be particularly important as sludge builds up in a septic tank. 
     Referring particularly to  FIGS. 2 and 4 , in one embodiment the riser  31  may be provided with legs  42  extending downward below the lower edge  39  of the body  32  of the riser  31 . These may support the body  32  of the riser  31  at a level above a support surface, such as the bottom of a septic tank  10  or paver or block  21  positioned at the bottom of a septic tank  10 . In one embodiment, the legs  42  may be made of short sections of polymeric pipe, such as ABS or PVC pipe, and may fit snugly into cylindrical channels or bores  43  in the body  32  of the riser  31 . 
     In another embodiment, as shown in  FIG. 4 , the diameter of the bore  43  may be chosen such that the legs  42  fit snugly in them. The bores  43  may extend upward into the body  32  of the riser  31 . The bores  43  may be formed to be coaxial with cylindrical recesses  33  in the upper surface  34  of the body  32  of the riser  31 . In such case, in one embodiment, the bores  43  may have a diameter greater than that of the recesses  33  and a shoulder  44  may thus be formed that may limit the depth to which the legs  42  may be inserted into the bore  43 . In one embodiment, 1 inch PVC Schedule 40 pipe may be used for the legs  42 . This material is easily cut with hand tools to a desired length, and is sufficiently strong and rigid for this purpose. The lengths of the legs  42  may be selected such that the pump  18  may be supported above a support surface such as the bottom of a septic tank  10 . As PVC pipe is readily cut, the length of the legs  42  may be selected and the legs  42  may be cut in the field. Of course, the bores  43  and recesses  33  do not have to be coaxial, and their shapes need not be cylindrical. 
     As mentioned above, the dimensions of the bores  43  and legs  42  may be chosen such that they form a frictional engagement when assembled together. This frictional engagement may be sufficiently strong so that an assembly of pump  18  and riser  31  may be lowered into a septic tank  10  without the pump  18  disengaging from the body  32  of the riser  31  and without the legs  42  disengaging from the bores  43  in the body  32  of the riser  31 . Of course, the legs  42  could be secured by adhesive in the body  32  of the riser  31  if desired. 
     The body  32  of the riser  31  may be made by any of a variety of known techniques, such as by machining, fastening together of various components using fasteners or adhesives, and the like, but molding provides an inexpensive and rapid method for such manufacture. 
     Although the present invention has been described in considerable detail with reference to various embodiments, other embodiments are possible. Therefore, the spirit or scope of the appended claims should not be limited to the description of the embodiments contained herein.