Double acting piston pump

Aug. 13, 1935.

J. M. SHARP

DOUBLE ACTING PISTON PUMP

Filed April 18, 1934

2,011,304

Sheets-Sheet 1

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INVENTOR

JEFFERSON M- SHARP

ATTORNEY

Aug. 13, 1935.

J. M. SHARP

2,011,304

DOUBLE ACTING PISTON PUMP

Filed April 18, 1934 2 Sheets-Sheet 2

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FIG FIG. 2 &amp; FIG.&lt;5.

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’•Y

ATTORNEY

Patented Aug. 13, 1935

2,011,304

UNITED STATES PATENT OFFICE

2,011,304

DOUBLE ACTING PISTON PUMP

Jefferson M. Sharp, Oil City, Pa., assignor to National Transit Pump and Machine Company, Oil City, Pa., a corporation of Pennsylvania

Application April 18, 1934, Serial No. 721,094

Claims. (Cl. 103—175)

The primary object of this invention is, to provide a double acting piston pump having a higher degree of volumetric efficiency than other pumps . of this type heretofore produced.

The other objects are: '

To provide a general service pump suitable for pumping volatile liquids of various kinds of which gasoline is a common example.

To provide a pump which may be readily con10· verted into a compressor or vacuum pump having a volumetric efficiency approximately equal to machines primarily constructed for these specific purposes.

Still another object is to provide a pump cylin15' der in which the axes of all of the valve ports extend vertically and the faces of the valve decks adjacent to said ports respectively extend in parallel horizontal planes so that they maybe machined at a' single setting of the cylinder cast20 ing, whereby-a material reduction in cost and increase of facility of manufacture, together with greater accuracy are attainable.

The practical embodiment of my inventive ideas whereby said objects are attained is clear 25 ly illustrated in the accompanying drawings in which:

Fig. 1 is a central, vertical longitudinal section through a pump cylinder organization constructed in accordance with my inventive idea.

This section is taken on line I—I of Fig. 2.

Fig. 2 is a vertical transverse section on line II—II of Fig. 1.

Fig. 3 is an enlarged, vertical transverse section of that portion’ of the pump cylinder which 35, includes,'and is adjacent to, the suction and discharge valves; the, point at which this section is taken is also on line II—II of Fig. 1.

-Fig. 4 is an enlarged view partly in side elevation and partly, in central, vertical section, of 40 the ' type of valve shown in Fig; 2.

- Fig. 5 is a central, vertical section of the type of suction valve shown in Fig. 3.

^: The'construction shown in said drawings, is a double acting pump, the details of which are sub45 stantially as follows:

The cylinder organization or main casting comprises a cylinder I in the bore of which a piston 2 reciprocates, with a stroke of sufficient length to cause the respective end faces of said piston 50 to approach very nearly into contact with the respectively adjacent end walls of the cylinder bore; a tubular suction member is shown at 3; the inlet port of which is indicated by the numeral 4; two oppositely disposed, laterally ex55 -tending, arcuate tubular branches 5, 5, lead from.

the duct of said suction chamber to the ports in which the suction valves 6, 6, are mounted; the suction valve deck is indicated at 7, 7; this deck forms a horizontally disposed floor or lower wall of the valve chamber 8—8 into which the upper 5 portion of said valves extend and in which said upper portions are housed; a port 9 leads from each of said valve chambers, respectively, into the adjacent side of the bore 10 of said cylinder I. The extreme wall of each of said ports 9 is in 10 substantial coincidence with the inner face of its respectively adjacent cylinder head 11 or 12; the lower wall or line of said ports being in proximity: to the bottom wall of the cylinder bore.

Any suitable type Of valve may be mounted in 15 said inlet valve ports, and the particular type chosen will depend upon the class of service in which the pump is used; the type of valves shown in the drawings, Figs. 2 and 3, also as details in Figs. 4 and 5, are well known types of commercial 20 valves which are both largely used in pumping liquids, both hot and cold, including water, the more viscous liquids, also volatile liquids; a suitable type of valves for use in compressors may be substituted when the pump is being used as a 25 compressor. , As shown in Fig. 3, the axial line A—A of said valves is spaced laterally outside of the structural limits, that portion of the cylinder organization which extends above the suction valve housing, as indicated by the dimension X, 30 thus providing the freedom of access to the suction valve decks for the purpose of machining them, as well as for inspection and replacement of suction valve element when necessary.

The arrangement of the cylinder organization 35 in all of its parts from, the inlet passage 3 upwardly, including the arcuated passages 5, the concentric position of suction valves 6 at the upper ends of said passages, the close proximity of said valves to and below the center of the bore 40 (0 of the cylinder, the position of the discharge valves 17 directly above the center of said bore at their respective ends of the cylinder organization are all so constructed and relatively positioned as to cooperatively produce a substantial- 45 ly direct upward flow of fluid through the pump, which flow is not impeded by either abrupt turns or reversals of direction. This attainment is in advance of any thing of which applicant is aware in this type of a pump, and is conducive to both 50 volumetric efficiency and reduction of the power requirement of the pump.

For the purpose of aiding in the attainment of the efficiency above mentioned by the construction of the cylinder organization proper (in addi- 55

2,011,304 tion to the employment of supplementary elements for this purpose), the upper faces 13 of the suction valve housings are formed at an outward, downward trend of substantially 45 de5 grees; the valve chambers of said housings are of circular form and their assumed axes extend perpendicularly to said angle. In order to eliminate the surplus volume or space which this construction produces in the chambers 8 of said housings, 10 (and which would otherwise lower the volumetric efficiency of the pump) there is introduced into each of said chambers an insert filler or clearance reducing member, as indicated at ί 4 in Fig. 2 or (5 in Fig. 3, in conformity to the type of 15 valve employed.

The chamber wall-contacting faces of said fillers are so formed as to be a contacting counterpart of the walls of said chamber, which walls may or may not consist partially of a portion of 20 the periphery of the cylinder liner; the portions of said fillers which are in juxtaposition, respectively to a valve, are a spaced counterpart or enlarged entaglio of the valve structure except that portion of said fillers which is open to afford 25 unrestricted passage of fluid to and through the cylinder ports 9. Said spaced relation is maintained by means of the shoulders 84' or 8 5' respectively, and said fillers are secured in position by means of the cover plates IS, and these 30 plates may in turn be secured in position in any suitable manner. The construction thus produced affords the utmost facility of insertion and removal of said fillers, since both of these functions may be performed by the simple movement 35 of the filler in the direction perpendicular to the face 13.

Said clearance reducers are retained in their service position by means of the cover plates 8 S, which plates may be secured in position in 4θ any suitable manner, as by screws, bolts, or a yoke such as commonly employed for like purposes.

In respect to the arrangement and mounting of the discharge valves 17—17, it will be readily 45 noted by reference to Fig. 1 that the ports 18—88, at both ends of the cylinder extend directly through the wall of the cylinder; that the upper face of the decks 89, 89, of said ports is horizontally disposed, thus causing said faces to be 50 parallel with the corresponding faces of the decks, 7, 7, of the inlet valves; the axial line of all of these ports are true vertical, also· parallel lines; this arrangement is materially conducive to. facility and economy of manufacture of this pump, 55 because machining operations upon all of these ports and their deck faces may be accomplished at a single setting up of the casting.

The discharge passage 20 in conjunction with its wall 21, form a housing for the discharge ⁶⁰ valves; said passage also functions as an outlet for the pumped fluid, which is finally discharged from the pump through the outlet 22.

The pump shown' is adapted to be operated by any suitable power appliance, (such as a direct⁶⁵ acting steam cylinder) to which it may be connected by means of the tie rods 23, 23.

The cylinder head 8 8 is provided with a stuffing box 25 through which the piston rod 20 operates. ₇₀ The working limits of the cylinder are defined by the inner faces 27, 27, of the cylinder heads, and the extreme walls of all the valve ports are caused to coincide with said faces so that no portion of the actuated fluid can be entrapped be75 tween the juxtaposed faces of said heads and the piston, at the instant of extreme limit of the piston stroke in either direction.