Box lubrication pump

Abstract

A box lubricator that includes a pump with a piston housing and piston. The piston housing extends from a first end to a second end, and includes a bore extending through the piston housing from the first end of the piston housing to the second end of the piston housing. The piston housing also includes a recess disposed at the second end of the piston housing, the recess being concentric with the bore and comprising a diameter larger than a diameter of the bore. The piston is disposed inside the bore of the piston housing. At least one elastomeric seal is disposed inside the recess of the piston housing and around the piston. In some embodiments, a ball and socket joint connects the piston to the rocker arm assembly. In some embodiments, a fluid passage and a check valve are disposed inside the piston.

1 . A piston assembly comprising:
 a piston housing with a first end opposite a second end, the piston housing further comprising;   a bore extending completely through the piston housing from the first end of the piston housing to the second end of the piston housing;   a piston housing inlet intersecting the bore between the first end of the piston housing and the second end of the piston housing; and   a piston housing outlet disposed at the second end of the piston housing and in fluid communication with the bore; and   a piston disposed inside the bore of the piston housing and comprising a first end opposite a second end, the piston further comprising;   a fluid passage formed inside the piston and fluidly connecting the piston housing inlet and the piston housing outlet;   a first recess formed inside the first end of the piston and in fluid communication with the fluid passage and having a diameter smaller than a diameter of the piston and larger than a diameter of the fluid passage;   a check ball disposed inside the first recess; and   a retaining guide disposed inside the first recess that limits displacement of the check ball to the first recess.   
     
     
         2 . The piston assembly of  claim 1 , wherein the piston housing further comprises:
 a second recess disposed at the second end of the piston housing concentric with the bore and comprising a diameter larger than a diameter of the bore; and   at least one elastomeric seal disposed inside the second recess of the piston housing and around the piston.   
     
     
         3 . The piston assembly of  claim 1 , wherein the check ball comprises a diameter larger than the diameter of the fluid passage, smaller than the diameter of the second recess, and smaller than a depth of the second recess. 
     
     
         4 . The piston assembly of  claim 1 , wherein ribs are formed inside the first recess and extend substantially an entire depth of the first recess. 
     
     
         5 . The piston assembly of  claim 4 , wherein channels are disposed between the ribs and circumferentially space apart the channels inside the first recess. 
     
     
         6 . The piston assembly of  claim 5 , wherein the retaining guide is an annular cylinder press fitted inside the first recess against the ribs.