Patent Publication Number: US-6212999-B1

Title: Automatic throat packing torque clip

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 60/070,367, filed Jan. 2, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     Reciprocating piston pumps for use in pumping paints and other viscous materials have been well known. Some of these pumps, are non-adjustable and thus when they start to leak must be repacked. Current adjustable designs are also susceptible to mis-assembly in variations in torque which lead to substantial variations in packing life. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to provide a pump which is easily manufactured and further which may be consistently manufactured thereby leading to increased packing life. 
     In the instant invention, the torque clip is made from precision music wire which gives the design a tight wire diameter tolerance to be re-used indefinitely without requiring cylinder assembly externally which makes it easily accessible for removal once the pump begins leaking in the throat area. 
     With this design, the manufacturing consistency is improved greatly by taking the possibility of over-torqueing out of the equation. With the instant design, the operator installs the clip on the throat nut and then screws the throat nut into the cylinder housing until it sets on to the clip thereby resulting in no variance in packing squeeze which was formally induced by the throat nut. Testing has shown that packing squeeze can decrease the pump life by up to one half of its normal life if it is done improperly. 
     The same reasons that provide consistency in original manufacture also provided to the end user when the pump is repacked. 
     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 
     FIG. 1 shows the instant invention generally designated  10  and comprised of a pump rod  12  and cylinder  14 , a retaining clip  16  and a throat nut  18 . In the preferred embodiment, the clip  16  is made of music wire which has both very high tolerances (plus or minus 0.001 inches) and is a type of spring steel. In particular, depending on the size pump, the diameter of the wire may range from 0.095 to 0.138 inches. 
     It is contemplated that various changes and modifications may be made to the torque clip without departing from the spirit and scope of the invention as defined by the following claims.