US1773363A - Pressure-packed pump piston - Google Patents

Description

Aug. 19 1930. KlBELE PRESSURE PACKED PUMP PISTON Filed Aug. 5, 1929 2 Sheets-Sheet l E. KIBELE Aug. 19, 1930.

PRESSURE PACKED PUMP PISTON Filed Aug. 5, 1929 2 SheetsSheet 2 Patented Aug. 19, 1930 UNITED STATES PATENT orricn EUGENE KIBELE, DECEASED, LATE 01' SAN ANTONIO, TEXAS, BY EUGENIA KIBELE soHRoEnER, nxncurnrx,

or SAN ANTONIO, TEXAS PRESSURE-PACKED PUMP PISTON Application filed August 5, 1929. Serial No. 383,625.

This invention relates to improvements in pump pistons and more particularly to pump pistons for use in double acting pumps, such as are ordinarily employed in well drilling.

The invention is, however, not confined to this particular use.

In the operation of pumps of this character, -it is necessary to pump liquids having therein a certain amount of sand and other foreign material tending to be caught between the piston and the cylinder wall, and thus cause rapid wear between the. working parts.

It is an object of the invention to provide 16 a pump piston which will automatically be held in close engagement with the cylinder wall and serve to avoid the usual difiiculty of the entrance of sand between the packing and the cylinder.

It is another object to provide a pump piston wherein the opposite ends of the packing ring are forced into engagement with the cylinder wall, particularly on the advancing end of the piston and adapted to withstand a large amount of wear .before leakage occurs.

Other objects include the manner in which the packing ring is held in position upon the body of the piston, and the manner in which the pressure is exerted upon the packing ring at the advance end thereof. These objects and the means by which they are accom-- plished will be set out in greater detail in the specification which follows.

Referringto the drawing herewith, Fig. 1 is a central longitudinal section through a pump piston embodying the invention. Fig. 2 is, an end elevation thereof. Fig. 3 is a broken longitudinal section through a pump piston illustrating a slightly different em bodiment thereof. Fig. 4 is a transverse section on the plane H of Fig. 3. Fig. 5 is'a view similar to Fig. 1 illustrating a third embodiment of the invention. Fig. 6 is an end elevation of the Fig. 5 embodiment, and Fig. 7 is a transverse section on the plane 77 of Fig. 5. Fig. 8 is a broken section showing the piston compressed within the cylinder. Like numerals of reference are employed to designate like parts in all the views.

In constructing the invention, there is secured upon the. end of a piston rod 1,'of the usual construction, a piston body 2, shapedto fit said piston rod and having a forward cylindrical portion 3. The rearward end ofthe piston is formed with an outwardly projecting flange 4 of substantially the samediameter as the piston. The outer face may be formed with an annular recess 5 therein.

On the forward end ofthe piston is a follower plate 6 which is of the same diameter as the flange 4 and is fitted over the end of the piston rod and adapted to be clamped longitudinally along the rod by means of a nut 7 Between the follower plate and the flange 4 is thus formed an annular seat for the packing ring 8 of some compressible wear-resisting material, such as rubber. The inner face of the packing ring is formed with a rib 9 flaring somewhat toward the inner face, as shown in Fig. 1. Said rib furnishes a means for attaching the packing ring firmly upon the piston.

To engage therib 9 of the packing ring, the piston body is formed with an innerprojection 1O thereon, adapted to fit within the groove 11, formed in the packing ring, and said projection is corrugated on its forward face to more firmly grip the packing ring. The follower plate 6 is formed with a similar projection 10, also corrugated on its inner face, to engage against the packing ring.

The packing ring is formed with its forward and rearward sides projecting slightly outward to form lips 12 and 12 which project somewhat beyond the outer face of the piston so as to resiliently press against the cylinder walls at both ends. Betweenthe ends of the packing ring and the flange 4 and also adjacent the follower plate there is left a slight gap, or breathing space, 13, which serves to allow a slight circulation of fluid theret-hrough on the advancing side of the piston.

It is desired to use the force of the compressed liquid which is pumped to assist in holding the packing ring 8 against the cylinder. There is, therefore, a series of openings 14 in the flange and 15 in the follower plate to allow the entrance of fluid on the 100 under side of each end of the ring. To provide for the enga ement of the compressed fluid with the pac ing ring the said ring is beveled on each side of the inner rib, as shown at 16, and the rearward face of the projections 10 and 10' are beveled off, as shown at 18, so as to form a chamber 19 therein. v

In the operation of this piston, it will be noted that the follower plate 6 can be clamped so firmly against the packing ring 8 that no fluid can find an entrance inwardl the seat in which the ring is fitte There can, therefore,be no wear between the body of the piston and the follower plate on. the

inner side of the packing ring. When the piston is inserted within the cylinder 25, as shown in Fig. 8, the lips 12 and 12' will be crowded inwardly so as to lie approximately flush with the iston body. The material at the ends will l fe compressed so that it will bulge inwardly into the pressure chambers 19 as seen in the figure. This causes a pressure outwardly at the ends that will continue until a material amount of the ring is worn away before any trouble with leakage may occur. When the piston is moved in a forward direction, the pressure of the fluid entering through the openings 15 will allow the liquid to engage beneath the forward end of the ring and force it with some pressure against the face of the cylinder. This will tend to throw the rearward end of the packing rin against the flange of thepiston body, thus c osing the breathing space 13 at the rearward side. The suction exerted through the openings 14 will also tend to assist inthe closure of the rearward breathing space. Sand and sediment, finding its way past the outer edges of the follower plate, will be prevented from passing the packing ring 8 by the pressure of the ring against the wall ofthe cylinder. When the end of the forward stroke of the piston occurs, the space 13 at that end will be opened and any fluid or sand at that pointwill be drawn through the said gap 13 and will pass out with the liquid through the openings 15 on the backward stroke when the suction walls of the projections 10" are smoothinstead of corrugated, and under ordinary conditions the smooth face will be entirely effective to maintain a tight closure against the entrance of fluid along the surface of contact between the piston and the packing ring.

There is a further change in this modification, in that the rearward faces of the protoward jections 10 are formed with recesses or grooves, 20, adjacent the openings 14 and 15, so as to form a series of pressure chambers beneath the ends of the piston ring for the fluid so as to form a greater surface against which thefluid may act to force the ends of the packing ring outwardly. It will be noted that the operation of this construction will be practically the same as that previously described in connection with Figs. 1 and 2.

In Figs. 5 to 7, inclusive, the construction of the packing ring 8' is modified to the extent that the outer face is concave by incliningr the walls in a straight line from the forward and rearward lips to the center line of the packing ring. The outer face of the packing ring is not curved between its ends but is formed with a plurality of inclined faces forming an obtuse angle midway between the ends of the ring.

Another change in this embodiment over that disclosed in Fig. 1 is in the making of the projections 22 on the body of the piston and the follower plate, respectively, detachable from the adjacent parts of the piston head. This is accomplished by making the rings shaped to fit the seat formed between 'the flange and the follower plate and securing them in position by means of set screws 21. This allows the rings 22, thus secured in position, to be detached and replaced, if wear occurs thereon, toward the' ends of the piston where the fluid contacts therewith. Different sized rings 22 may be provided as wear on the packing ring 8 occurs if desired. In this manner the edges of the packing may be forced outwardly to better engage the cylinder wall. The shape of the assembled piston body and the means whereby the ring is clamped in position are not materially different from that shown in the Fig. 1 embodiment. a

It will also be noted that the follower plate may be recessed slightly, as shown at 23, on its outer face so as to better direct the pressure fluid into openings leading to the space below the ends of the packing ring.

In each one of these separate embodiments the packing ring itself has been shaped so that it will naturally bear outwardly toward the piston Walls at each end. The clamping of the inner rib 9 between the follower late and the body of the piston will tend to orce it outwardly at the ends, due to its compression and also to the tapered contact between the projections 10 and 10 on their outer faces, as'shown at 16.

,The use of the fluid to assist in forcing the piston ring outwardly has been disclosed in previous applications of applicant for patent thereon, but the employment of breathing spaces 13 and 13 at the ends of the packing ring whereby sand may be eliminated from I the surface of contact between the piston and cylinder is an important feature of the invention, in that it serves to avoid the usual rapid wear of the'piston, due to sand, and increases the life of both the piston and the cylinder. It is also to be noted that the manner in which the piston is formed, so that the fluid may not enter around the rib 9 of the packing ring so as to Wear the body of the piston, is a feature of advantage and of novelty.

The breathing space 13 has been shown in the drawings and described but obviously this may be dispensed with and the packing ring made of the proper length to snugly fit between the piston head and follower plate, or the follower plate may be drawn up by the nut 7 to eliminate the breather space.

Having thus described the invention, the further advantages of which will be apparent to those skilled in the art, what is claimed as new and desire to protect by Letters Patent is: a y

1. A pump piston comprising a piston rod, a piston body thereon, a follower plate adapted to be clamped to said piston body, there being an annular packing seat on said piston, a packing ring having an inner morticed rib thereon in said seat, projections on said body and said follower plate adapted to engage said rib, the inner faces of sald projections converging outwardly beneath the ends ofthe packing ring, said ring being formed to allow the passage of liquid at its advancing end, and means to allow entrance of pressure fluid beneath the said ends of said ring.

2. A pump piston comprising a piston body and a follower plate adapted to be clamped together, an annular packing ring seat between the ends of said piston, a packing ring 4 of compressible material in said seat, an inner morticed rib on said ring, projections on the ends of said seat overlying said rib, the ends of said ring outside said projections being forced outwardlythereby, and means to admit fluid beneath the ends of said ring, said ring being slightly shorter than said seat for the purpose described.

3. A pump piston comprising a piston body, an end flange thereon, a follower late, means to clamp said plate to said body orming a central annular seat between said flange and plate, a packing ring of compressible material in said seat, an inner rib on said ring, projections on said piston body and said plate overlying the ends of said rib, said projections being inclined outwardly toward the ends of the piston, there being a slight space between the ends of said ring and the sldes of said seat, and means to allow entrance of fluid beneath'the ends of said packing ring.

4. In a pump piston, a iston body aving an annular packing seat between its ends, a

, packing ring of compressible material in said seat, the ends of said seat being inclined to

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