US2786425A - Pump liner tightening attachment - Google Patents

Description

March 26, 1957 C. G. YARBROUGH PUMP LINER TIGHTENING ATTACHMENT Filed Feb. 19. 1954 ATTORNEY United States Patent PUMP LINER TIGHTENING ATTACHMENT Carl G. Yarbrough, Corpus Christi, Tex.

Application February 19, 1954, Serial No. 411,400

1 Claim. (Cl. 103-216) This invention relates to a novel attachment for a conventional liquid pump and has for its primary object to provide a structure which will maintain a constant pressure on the pump liner while the pump is in operation for compressing the packing between the liner and the pump hon-sing or casing to prevent leakage of the pumped medium between said liner and casing and past the packing.

More particularly, it is an object of the present invention to provide a novel pump attachment which will utilize a portion of the pressure of the pumped medium for maintaining a constant pressure on the pump liner packing proportionate to the pressure of the pumped medium and which accordingly will be sufiicient at all times to prevent leakage past the packing.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:

Figure 1 is an elevational view of the attachment shown in an applied position, and

Figure 2 is an enlarged longitudinal sectional view, partly in elevation and partly broken away thereof.

Referring more specifically to the drawing, for the purpose of illustrating a preferred application and use of the pump liner tightening attachment, designated generally 5 and comprising the invention, a portion of a conventional pump has been illustrated including a part of the pump casing or housing 6 having a head 7 at one end thereof for closing an end of the barrel or bore 8 of the casing 6. The casing 6 includes an outlet portion in the form of a bore 9 which extends laterally from the bore 8 adjacent the head 7 and to which an outlet conduit 10 for the pumped medium is connected, as seen in Figure 1. A sleeve 11 forming a pump liner is slidably disposed in the bore 8 and extends slidably through an internally restricted annular casing portion 12 of the bore 8 which forms an annular packing seat which faces toward the head 7. The liner 11, adjacent an outlet end 13 thereof, is provided with an outwardly projecting annular enlargement or shoulder 14 which is disposed between the packing seat 12 and the outlet passage 9. One or a plurality of packing rings P are disposed around the liner 11 within the bore 8, between the seat 12 and said enlargement 14. The open end of a conventional valve cage 15 fits over the liner end 13 and against the enlargement 14 and extends from said liner end to adjacent the casing head 7 and has an end wall 16, located adjacent said casing head. The parts 6 to 16 inclusive constitute no part of the present invention but have been illustrated and briefly described to afi'ord a better understanding of the liner tightening attachment 5.

In lieu of a bolt, not shown, which is usually threaded through the head 7 to bear against the cage end 16 for maintaining a pressure on the packing P and which is dispensed with when the attachment 5 is employed, said attachment includes a cylinder 17 having an end wall 18 which is suitably secured against the outer side of 2,786,425 Patented Mar. 26, 1957 the pump casing head 7. Said end wall 18 is provided with a stufling box 19 the bore of which aligns with an opening 20 of the pump casing head 7. A piston 21, provided with a piston ring 22, is slidably disposed in the cylinder 17 and has a piston rod 23 projecting from one end thereof. The piston rod 23 extends slidably through the stufling box 19 and opening 20 and bears against the cage end 16. The other end of the cylinder 17 is closed by an end wall or head 24 having a threaded opening 25 through which an elongated bolt 26 threadedly extends. Preferably two jamb nuts 27 are threadedly mounted on the bolt 26 outwardly of the cylinder head 24.

A small branch pipe or conduit 28 has one end connected to and communicating with the outlet conduit 10 between the pump casing 6 and a regulating valve 29 of said conduit 10. The other end of the branch conduit 28 is connected to a boss 30 of the cylinder 17 and opens into said cylinder between the piston 21 and cylinder head 24. The branch conduit 28 may also be provided with a regulating valve 31.

The bolt 26 is normally advanced inwardly of the cylinder head 24 to move the piston 21 toward the pump casing head 7 for displacing the piston rod 23 through said pump casing head and against the cage head 16 for moving the cage 15 and pump liner 11 from left to right as seen in Figure 2 for compressing the packing P to prevent leakage of the pumped medium between the liner 11 and pump casing 6 when the pump is in operation. The jamb nuts 27 are then advanced to their positions of Figure 2 to retain the bolt 26 in its advanced position. However, after the pump has been in operation for a period of time a certain amount of play or looseness will develop in the packing P allowing escape of some of the pumped medium back between the liner 11 and pump casing 6, especially when the medium is being pumped at a high pressure. To avoid this loss of pressure and to maintain the packing P tight at all times when the pump is in operation, the attachment 5 is provided. With the pump in operation and with the valve 31 open or partially open, a part of the pumped medium in the conduit 10 will flow through the branch conduit 28 into the cylinder 17 between the cylinder head 24 and piston 21 to produce a pressure in this portion or chamber 32 of the cylinder substantially equal to the pressure in the pump. This pressure will cause the piston 21 to be moved from left to right producing a movement in the same direction of the piston rod 23 for exerting a pressure against the cage 15 and liner 11 likewise from left to right as seen in Figure 2 for increasing the pressure on the packing P. It will be obvious that this additional pressure on the packing P will vary in proportion to the pressure at which the medium is being pumped and will eifectively prevent any leakage of the pumped medium through the packing. Before interruption of the operation of the pump occurs, the bolt 26 may be advanced back into engagement with the piston 21 which has been displaced out of engagement therewith by the pressure in the chamber 32, for maintaining the pressure on the packing P produced by the attachment 5 during operation of the pump.

The cylinder 17 is provided with a small drain port 33 near its end 18 for venting the cylinder between the piston 21 and cylinder end 18 and to permit escape of any of the pumped medium which might pass into the cylinder through the stuffing box 19. An excessive escape of the pumped medium through the drain 33 will indicate a worn condition of the packing of the stuffing box 19.

Various modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claim.

I claim as my invention:

The combination with a pump casing having a head at one end thereof, said casing including a bore provided with an internally restricted portion disposed adjacent the head, a liner disposed in the bore and extending slidably through said internally restricted portion, said liner having an external shoulder disposed between the casing head and said internally restricted portion, a packing disposed around the liner between said shoulder and the internally restricted portion, a valve cage loosely mounted in the pump casing between the head and liner and having an end bearing against the end of the liner disposed adjacent the head, said pump casing having an outlet passage for a pumped medium under pressure; of a pump liner tightening attachment comprising a cylinder having an inner end wall and an outer end wall, means securing said inner end wall to the outer side of the casing head for mounting the cylinder substantially in alignment with the casing bore, a piston reciprocably mounted in the cylinder, a piston rod fixed to said piston and extending slidably through the inner end of the cylinder and through the casing head, said rod having one end disposed in the casing and bearing against the cage, a conduit having one end opening into the cylinder between the outerend wall thereof and the piston, said conduit having an opposite end communicating with the outlet passage of the pump for supplying a portion of the pump medium under pressure to the cylinder between said outer end wall and the piston whereby the piston and piston rod are displaced toward the casing for exerting an axial thrust against the cage and liner in a direction away from the casing head to compress the packing between the liner shoulder and the internal restricted casing portion, and manually adjustable stop means extending through said outer end wall of the cylinder and disposed to be engaged by the piston for limiting movement of the piston toward said outer end wall of the cylinder.

References Cited in the file of this patent UNlT ED STATES PATENTS 2,198,301 Campbell Apr. 23, 1940 2,312,891 Ferris Mar. 2, 1943 2,650,868 Waldron Sept. 1, 1953 2,686,090 Leman Aug. 10, 1954

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