Patent Publication Number: US-6212998-B1

Title: Packings on pump rod

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. Provisional Application No. 60/070,353, filed Jan. 2, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     Reciprocating piston pumps have been well known for many years for paint and other viscous materials. While current designs are generally satisfactory for their intended use, users are always desirous of increased packing life so as to prevent interruption of jobs and productivity. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to provide a pump which is easily and inexpensively manufactured. 
     This invention serves to eliminate parts and assembly time, provide a nonadjustable packing cluster and with an increased stack height which provides more load carrying capabilities and running true to the cylinder which will result in an increase of as much as 50% over standard packing life and eliminate torque sensitive packing adjustments. 
     The pump rod is machined to allow relief with a shoulder that provides an area where the packings and glands slide on to the rod. This provides exact alignment and runout to the upper portion of the rod and to which throat packings and glands align as well. This allows for minimal side loading or twisting between the two sets of packings and glands. It also provides a one piece piston that can be screwed into the end of the rod to compress the packing cluster to a predetermined compression tolerance and eliminates multiple assembly pieces and torque settings for the packings. 
     An additional leather and UHMWPE packing are added to the piston to eliminate any rocking of the piston which causes gland wear against the cylinder which may lead to reduced life. Using the various features of the instant invention, a packing life increase of greater than 50% has been observed compared to current designs. 
     Piston life is increased by over 50% to the precise alignment of the rod and upper throat packings and glands and precise tolerancing. The packings are preloaded to a predetermined compression tolerance for ease of installation and maintenance. Current assemblies include a piston with a torque nut to assemble the head of the piston and a rod. This leaves the runout tolerances to be determined by threads on the piston and piston head along with torque nuts and LOCTITE®. Such designs can result in premature piston failure. 
    
    
     These and other objects and advantages of the invention will appear more fully from the following description made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views. 
     A BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view detailing the instant invention. 
     FIG. 2 is a cross-sectional view of the pump incorporating the instant invention. 
     FIG. 3 is an exploded view of the pump incorporating the instant invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The instant invention generally designated  10  is comprised of a cylinder  12  having a sleeve  14  thereon, a piston rod  16  having a shoulder  16   a  and a packing gland  20  along with a throat packing gland  22 . 
     It is contemplated that various changes and modifications may be made to the pump design without departing from the spirit and scope of the invention as defined by the following claims.