Piston bore undercut and methods of manufacturing a piston bore undercut for a series progressive divider valve

Abstract

A series progressive divider valve comprises a valve body and pistons. The valve body comprises a fluid inlet, piston bores, outlet bores, porting and undercuts. The fluid inlet extends into an exterior of the valve body. The piston bores extend through the valve body from a first end to a second end. Each piston bores includes a piston. The outlet bores extend into the valve body, each outlet bores comprises a first set of outlet bores and a second set of outlet bores. The porting forms a plurality passageways connecting the piston bores to each other and with the outlet bores such that when high pressure fluid is applied to the inlet each of the pistons reciprocates from the first end to the second end in sequence. An undercut is located at an intersection between each passageway and piston bore.

1 . A method of manufacturing a series progressive divider valve, the method comprising:
 drilling a plurality of piston bores from a first end to a second end into a parallelepiped valve block;   machining a plurality of undercuts in the plurality of piston bores between the first and second ends; and   machining a plurality of passages connecting the piston bores to each other, each of the passages extending from an end of a piston bore to an undercut.   
     
     
         2 . The method of manufacturing a series progressive divider valve of  claim 1  wherein the step of machining the plurality of undercuts comprises using a Woodruff tool to machine the undercuts. 
     
     
         3 . The method of manufacturing a series progressive divider valve of  claim 1  wherein the step of machining a plurality of undercuts comprises:
 machining a void adjacent a piston bore to increase a cross-sectional area of the piston bore. 
 
     
     
         4 . The method of manufacturing a series progressive divider valve of  claim 3  wherein the void comprises a cylindrical void surrounding the piston bore along an axial length to increase a diameter of the piston bore at right angles. 
     
     
         5 . The method of manufacturing a series progressive divider valve of  claim 1  wherein the step of machining a plurality of passages comprises:
 machining a first length having a first diameter that extends from an end of a first piston bore into the valve body; and 
 machining a second length having a second diameter smaller than the first diameter that extends from the first length to the undercut of a second, adjacent piston bore. 
 
     
     
         6 . The method of manufacturing a series progressive divider valve of  claim 5  wherein the axial length of the undercut is greater than the second diameter.