US2307451A - Hydraulic pump with mechanically actuated intake valve - Google Patents

Description

Jan. 5,1943. lc. J. COBERLY HYDRAULIC PUMP WITH MECI-IANICALLY ACTUATED INTAKE VALVE 2 sheets-sheet 1 Filed Aug. 2, 1940 /NVe/vTo/Q, 6 CLA/Qe/VCE d. Cosa-RLY'- y HA Ave/5 K/chg Fos 71s@ a HAR/ef; f L

c. J. coBERLY 2,307,451' HYDRAULIC PUMP WITH MECHANICALLY ACI-UATED INTAKE VALVE Filed Aug. 1940 2 sheets-sheet 2 Jan. 5, 1943.'

Patented Jan. 5, 1943 HYDRAULIC PUMP WITHMECHANICALLY i Ac'rUA'rED INTAKE VALVE ,y

Clarence J. Coberly, Los Angeles, Calif., assignor to Roko Corporation, Reno, Nev., a corporation of Nevada Application August 2,1940, serial No.,35o,o11

7 claims.r (c1. 10s-16s) My invention relates to the pump art, and more particularly to a fluid operated pumping device Y adapted to be used in wells.

Although my invention is capable of many uses, it is of particular utility in connection with a iiuid operated pump for use in oil wells, and, consequently, for the purpose of illustration will be described in connection therewith, although it is to be understood that I do not intend to be limited to such use of the invention.

This invention is an improvement over the construction shown and claimed in my Patent No. 2,081,222, issued on May 25, 1937, to which reference is hereby made.

In the hydraulic pump art it is standard practice to provide a iiuid operated pump having a fluid operated motor operatively connected to a pumpingunit adapted to pump fluid from a well to the surface of the ground. Such a device :is shown and described in my Patent No. 2,134,174, issued October 25, 1938, and since the fluid operated motor of such device is not a part of the present invention, it is not described in detail herein, reference being made to said earlier patent for the construction thereof. y* K In such prior art devices as shown in my said Patent No. 2,134,174, it is standard practice to provide a pump cylinder having a cylinder liner rigidly held therein, by shrinking or otherwise,

within which a pump piston is moved to pump fluid from the Well through suitable intake and discharge valves provided at each end of the pump cylinder. Such valves, as shown in my said Patent No. 2,081,222, are ordinarily formed of a number of parts which are expensive to manufacture and inconvenient to assemble. It is therefore a primary object ofthe present invention to provide an intake valve construction for such a pump which is relatively cheap to manufacture, easy to assemble, and yet positive in operation. I prefer to accomplish this by providing a movable cylinder liner in the pump cylinder adapted to actuate mechanically by its movement the intake valves of a pump cylinder, movement of the cylinder liner being accomplished by movement of the pump piston. 1

By mechanically operating the intake valves of my device, I am able to provide intake valves having ports of large area, thus adapting a pump equipped with my invention to handle uids of high viscosity so as to readily permit the pump cylinder to ll with the well fluid, an advantage not normally enjoyed by pumps having intake valves of the suction type as shown in my said Patent No. 2,081,222, in which the area. of the portsis limited bythe general space limitations existing in oil wellpumps andy with which it is impractical to pump fluids ofY high viscosity. -A further advantage of my improved type intake valves-is that theiroperation is positive because it is mechanical, thus preventing sticking which frequently occurs in the suctionv valves of the prior art when a viscous fluid is pumped.

It is also standard practice in the hydraulic pumping artwhere hydraulic pump unit is actuated by operating fluidconveyed to the pump unit under pressure through power tubing, to provide a special tubing bleeder in thev line of the power tubing4 adjacent the pump unit which -iriaygbe opened from the surface of therground when desired toV permit uid in the power tubing to draininto the well. Y Such tubing bleeders are normally used when the pump unit is to be. pulledto prevent what is known in the oilindustrylas a' wet job, such a tubing bleeder beingillustrated in my Patent No. 2,053,602, issued September 8, 1936. pensive to make and install, and, since they must be installed in the line of the power tubing above the pump, are never effective kto-drain the tubing'v 1 completely. It is therefore a further importantv object of my present invention to provide a fluid operated pumpunit in which a simple and practical power tubingbleeder is built intothe pump unit so that when the pump unit is raised from its pumping position in a well, substantiallyV all of the uid inthe power tubing may be drained therefrom into the well. Y

I haveV discovered that in operating a fluid operated pump in a well it is frequently desirable'or necessary to treat the well fluid in the well prior. to conveying it to the pump so as to render it suitable for pumping by such a fluid operated pump. Such treatment of the well uid may be to' cure avariety of defects in the characteristics of the well fluid. For example', in new oil Wells it frequently occurs that the well oil carriesarela-V eign materials pass through the pump fairly well,

Such prior art tubing bleeders are eX- rapid that frequent cleaning jobs on the pumping equipment are required, which is uneconomical and impractical in commercial operations. I have discovered that where oil to be pumped from a well contains high quantities of such foreign materials such as would render it impossible to pump it with standard pumping equipment, the percentage by volume of such foreign materials in the oil can be maintained below a predetermined maximum by diluting the well oil with clean oil during operation of the pumping equipment, which is a further object of my present invention. I prefer to accomplish this by diverting a portion of the clean oil normally used to operate the uid operated pump directly into the well oil in the well to dilute the; same .to

reduce the percentage of foreign materials by volume to a point at which the same will pass through the pumping equipment without clogging the same.

Another diiiculty occurs in deep well pumping whenthe ,well fluid, such as oil, is of high viscosity, in thata very viscous well fluid also tends to clog and gumY the moving parts of the pumping equipment, and isdifcult to handle therein, even with a uidoperated pump having a valve designed as illustrated, andL described herein. Accordingly, it is still another 'object of my invention to reduce the viscosity of well uid to be pumped from a wellbefore the same is conveyed to the pump. I prefer to accomplish this by diluting the well uid inthe well with a thinner during operation of the pumping equipment, such as, for example, keroseneA or other thin hydrocarbon wherean oil well is to be pumped which contains highly viscous oil. InA my preferred embodiment, such a thinner is added directly to the operating fluid normally used to'operateia uid operated pump, a portion thereof being diverted and mixed with the well oil during pumping.

Still another difficulty in pumping well oil from wells is that the well oil is of such a nature as to produce a high headv of foam on the top of the column of well oil, thus causing a pump inserted therein to pump substantial quantities of gas. This is ineicienty and otherwise undesirable, sometimes causing gas locks inl the pumping equipment. Therefore, it is another Aobject of my invention to treat well fluid in a well during pumping of the same with a de-foaming agent, ,such as, for example, kerosene, so as to break up the gas oil emulsion of such a foam. I prefer to accomplish this by conveying the de-foaming agent downwardly with the operating fluid normally used to operate a fluid operated pump, and to divert and discharge a part of such operating fluid directly into the well oil so as to reduce the foam therein.

Further objects and advantages of my invention will be evident from the specication and the drawings,l which are for the purpose of illustration only and in which:

Fig. 1 is a diagrammatic. utility view, partly in section, of my invention disposed in a well.

Fig. 2 is a vertical sectional view of the vmotor and main valve construction of my device.

Fig. 3 is a verticalsectional view of my device, continued downwardly from the bottom of Fig..1.

Fig. 4 isavertical sectional view of my device, continued downwardly from the bottom of Fig. 2.

Fig. 5'is a cross-sectional view taken on the line 5-5 of Fig. 3.

Fig. 6 is a cross-sectional view taken on theline 6 6 ofFig. 3.

Fig. 7 is a cross-sectional View taken on the line 'l--T of Fig. 4.

Fig. 8 is a cross-sectional View taken on the line 8 8 of Fig. 4.

Fig. 9 is a vertical sectional view of an alternative form of pump intake valve.

Fig. 10 is a cross-sectional view taken on the line I0-I0 of Fig. 9.

Referring to the drawings, Fig. l shows a cas-- ing ID set in a well, the lower end of which is lled with well fluid as indicated at I I, the upper end of the casing having a casing head I2 connected thereto on which is rigidly positioned a tubing head I3. The casing head I2 and the tubing head I3 may be of any type well known in the art.

Suspended from the tubing head I3 is a production tubing I4 provided at its lower end with a conical seat member I5, and also suspended from the tubing head is a power tubing l5 on the lower end of which is a fluid operated pump unit I1 which includes a motor unit and a pump unit, generally designated as I8 and I9 respectively. The conical seat member is provided with a port I5a for a purpose to be described hereinx after. The lower end of the pump unit I9 is provided with a tapered seat surface 28 adapted to seat in the conical seat member I5, making a fluid-tight joint therewith. Suitably connected to the tubing head I3 is a supply pipe 2l cornmunicating between the power tubing I6 and a source of supply of operating fluid under pressure (not shown), and also connected to the tubing head is a production pipe 22 communicating between the production tubing I4 and a point of discharge or storage (not shown). The casing head I2 is provided with a vent pipe 23 communicating with the interior of the casing I8 through which gas may bev taken off from the top of the casing.

Referring to Figs. 2 and 3, I show the motor unit I8. and valve mechanism 25 therefor, the specic'construction and operation of which are not apart of the present invention, being fully illustrated and described in my earlier Patent No. 2,134,174, to which reference has been made. The main parts of the motor unit construction, however, are a motor cylinder 28 closed at its upper end by a head2? and closed at its lower end by a central Yhead 28, and having a motor piston 29 adapted to be actuated therein by operating uid under vpressure delivered through the power tubing I6 and through the valve mechanism 25' alternately to opposite ends of the motor cylinder. `The motor piston 2? is provided with'an upper piston rod Sil which is connected to thel motor piston and extends upwardly through theupper head 2l and into the path of the operating uid delivered through the power tubing I6. Also connected to the motor piston 29 is an intermediate piston rod 3l which passes downwardly through the lower head 28 of the motor cylinder 26.

The pump unit I9 generally comprises a pump cylinder 33 threaded at its upper end to the central head 28 and threaded at its lower end to a lower head 34,- there being a cylinder liner 3S provided in the pump cylinder 33 so as to'be slidable relative thereto, the liner being supported as described hereinafter so as to provide a iluid space 35 therearound. A pump piston 3l is provided in the cylinder liner 3%, being connected to the lower end of the intermediate piston rod 3l, and has connected to its lower end a lower piston rod 38 which extends downwardly through the lower head 34. Ihe pump piston 31 is provided with piston rings 18 held in suitable annular piston ring grooves formed in the outer surface of the pump piston, which operate to form a sliding fluid-tight fit between the pump piston and the interior of the cylinder liner 36. The piston rings 18 are adjusted to create more friction between the pump piston 31 and the cylinder liner 36 than exists between the cylinder liner and the inner walls of the pump cylinder 1|) 33, for a purpose to be described later, but it will be apparent that the use of the piston rings is preferable only, and that any other suitable means may be used to provide friction between the liner and the pump piston without departing A from the spirit of my invention.

The lower end of the central head 28 is provided with a reduced diameter 39 and has formed therein an upper discharge valve means 49a, including an annular discharge valve chamber 4), 20 there vbeing an upper valve cage 4| abutting against the lower end of the central head 28 so as to close the valve chamber 49, being held in fluid-tight relation with the central head by means of a sleeve 42 threaded into the central 25 head 28 and having a iiange 43 engaging an annular shoulder 44 formed on the valve cage 4|.

A plurality of ball valve seats 45 are formed in a valve seat ring 46 set in a recess 41 in the valve cage 4|, each of which is adapted to seat a ball 30 valve element 48, all of the ball valve elements normally being held in seated position by an upper ring 49 held in yielding engagement therewith by a compression spring 59. Formed in the central head 28 and communicating be- 35 tween the upper portion of the valve chamber 4|) and the exterior of the central head is an upper discharge passage 5I. Formed in the upper portion of the valve cage 4| are passages 52, each of which communicates between the valve seats and the interior of the valve cage.

Cooperating with the lower end of the upper valve cage 4I is an upper poppet valve device 55, which includes an annular seat ring 56 rigidly set into the lower interior of the valve cage 4| 45 and provided with an outwardly directed beveled seat 51 adapted to cooperate with an internally beveled seat 58 formed on a valve member 59 threaded to the upper end of the cylinder liner and having upper intake ports 60 therein, 50 formed in a sleeve portion 6I telescoping over the lower outer end of the valve cage 4| and forming a sliding duid-tight t therewith and supporting the upper end of the liner in the pump cylinder 33. The upper intake ports 60 communicate at 55 all times with the upper end of the fluid space 35.

The lower hea-d 34 is provided with a lower discharge valve means 63 similar in construction to the upper discharge valve means 40a but inverted in position, which is adapted to discharge pumped 60 :duid through a lower discharge passage 64. Threaded on the lower end of the cylinder liner 36 is aA lower poppet valve device 65, similar in construction to the upper poppet valve device 55HV but inverted in position, and having lower intake ports 66. Also formed in the lower head 34 is an intake passage 61 communicating aroun-d the lower discharge Valve means 63 and the lower poppet valve device 65 with the uid space 35 around the cylinder liner 36. As will be noted, the pump piston 31 is provided with upper and lower tubular heads 31ar and 31h, respectively, which enter `the valve cages of the upper and lower poppet valve devices 55 and 65, respectively,

at opposite ends of the pump piston stroke to reduce the clearance volumeof the piston rods 3| and 38 at such times, so as to render the pumping device more ecient if the 'pumped ilui'd contains relatively high percentages of gas.

As will be noted, the lower piston rod 38 extends downwardly through the lower head 34 and is provided with suitable packing 68 therearound, and projects downwardly into a closure tube-69 threaded into the lower end of the lower head 34. Abutting against the lower end of the lower head 34 is a spacer element 16 having an inlet groove 1| formed therein which is adapted to be aligned with the intake passage 61 by means of a dowel pin-12 projecting into suitable registering openings in boththe lower head and spacer element. Engagingthe lower end of the spacer ele,- ment 10 is a guar-d sleeve v13 concentric with and spaced from the closure tube 69 -to protect the same, and which is adapted to be rigidly positioned relative to the spacerjelement by lock nuts' 14 threaded on the lower,- end of .the closure tube 69 and engaging an end ring 15 which in turn engages the guard sleeve.

Through the upper piston rod 30, the motor piston ,'29, the intermediate` piston rod 3l, the pump piston 31, and the lower piston rod 3B, is a longitudinal passage 16 communicating at its upper'endwith the interior of the power tubing I6 and communicating at its lower end with the interior` of the closure tube 69. Formed in the lower head 34 is a bleeder port 11 which communicates between the interior of the closure tube 69 and asemicircular groove 16a vformed in the exterior of the lower head at the approximate center of the'tapered seat surface 20 thereon.

In" operation, operating iiuid under relatively high pressure is conveyed downwardly through the powerV tubing I6 to the motor unit I8 through the valve 'mechanism 25 to reciprocate the motor piston 29 in the motor'cylinder 26, as described in my said Patent No.- 2,134,1'14. Reciprocation of the motor piston 29 causes a corresponding reciprocation of the pump` piston 31 in the pump cylinder ,"33. y The parts ofthe device are so de-V signedthat when the .upper poppet valve device 55 is'inits open position as shown in Fig. 3, the lowerpoppet valvedevice will be in its closed position as` shown in Fig. 4. When'in such position, well fluid mayk flow from the well through the inlet grooves 1| and the intake passage 61 into 'and Yupwardly through the fluid space 35 of 'the pumpunit I9, and may flow therefrom through the upper` intakeports 60 Vof the upper poppet valve device 55 into the upper end of the cylinder liner 36 above the pump piston 31. When the parts are in such( position, iiuidbelow the pump piston 31 may not now out through the lower poppet valve device 65, since the same is closed,l but iiows downwardly through the lower dischargevalve means 63'to discharge from the pump lunit ythrough the lower discharge passage 64. With the ypump piston 31 in the position shown in Fig. 4, it is just completing its downstroke. *When it starts its upstroke, friction created between the pump piston and the cylinder linerr'36 Yby the packing rings` 18 on the pump pistonwill-cause the cylinder liner to move upwardly j'with the pump piston until the valve member 59 of the upper `poppet valve device 55 seat's'o'n the beveledseat 51 of the annular seat ring 5B, at which time the upper poppet valve device'will be closedand the lower poppet valve devicewill be open. As soon as the valve member 59-"eiigages the annular seat ring 56, upward movement ofvlthecylinderliner 36 will b e stopped, y

the pump piston 31, the pump pistonfwillv move relative to the cylinder liner. Upon reversal of the direction of movement of the pump piston 3'I, the cylinder liner S6 will vthen move downwardly with the pump piston by reason of the friction created therebetween by the packing rings 'I8 to open the upper poppet valve device 55 and close the lower poppet valvel device 65. As will be understood, the upper vand lower poppet valve devices 55 and 65 comprise inlet valvemeans for the pump unit I9. By using ths'type of inlet valve construction, it is possible to make the area of the inlet ports as large as may be desired, so as to enable a hydraulic pump of my'present construction to be used satisfactorily in pumping fluids having high viscosity, which is a particular advantage of my invention.

During normal operation, the uid operated pump unit I'I is seated in the conical seat` member IES-of the production tubing I4, sothatthe groove 16a is out of registry with the port 15a so that the seat effectively closes the outerend of the bleeder port 'I'I. When the power tubing I6 is pulled from the well, to repair the fluid operated pump unit I'I, or for other reasons, it is desirable to permit the operating'uid therein to drain therefrom so as to prevent the operating fluid from flooding the area around the casing head I2 as the tubing joints are broken, known in the industry as a wet job. This is accomplished in my present construction by the bleeder port TI, which is open to the well as soon as the fluid operated pump unit II is raised from the conical seat member I5, thus" permitting the operating fluid in the power tubing I6 to drain therefrom through the longitudinal passagelfi of the piston rod, the closure tube 69, vand the mitted to drain downwardly through the conical.

seat member I5 and back into the well. so that the production tubing may ialso be pulled free` from the oil which would otherwise be therein. By providing this bleeder construction at the lower end of the uid operated. pump unit, substantiallyv all of the oil in both the production tubing I4 and the power. tubing I6 may be drained therefrom, which is a distinct advantage over.

the bleeder devices of the prior art. By incorpo'- rating my bleeder construction in my fluid oper-` ated pump unit, I also obviate the necessity of providing a separate bleeder., device above thed uid operated pump unit in the line of the production and power tubing, which would other-A wise be necessary, thus materially decreasing the cost of such installation and simplifying the assembly thereof.

In the event thatmy invention is intended to be used in a well in which the Well fluid has characteristics normally detrimental to the operation of the pump, such as, for example, unduly high foreign matter content or viscosity, or an unclesirable foam or emulsion condition, all as pointed out hereinabove, I provide means whereby the well fluid may be treated to render it suitable for pumping during the normal operation of my fluid operated pump unit II and prior to the timewhen the well fluid passes into the inlet of the pump unit through the groove 'I I This isaccomplished by relative rotation of the production tubing I4 and during the remainder-of the upward stroke of andthe power tub-ing I6 so as to cause the groove 16a to register with the port I5a, thus permitting a small portion of the operating fluid to discharge outwardly through the bleeder port 'II and the port IEa directly into the iiuid in the well. This discharge of operating fluid is preferably continued as long as necessary-during the operation of the fluid operated pump unit I'I. Due to the relatively small cross-sectional area of the port I5a, only a small proportion of the operating iiuid may be discharged therethrough, although, obviously, the size of the port I5a may be varied as desired, depending upon the pressure of the operating fluid and the amount of flow desired throughthe port I5a. Since the operating fluid is normally clean oil, or clean uid of the same type Vas that to be pumped, if it is desired to merely reduce the percentage by volume of foreign material in the pumped well fluid, a portion of the operating fluid may be diverted directly through the bleeder port TI and the port I5a to dilute the well fluid in the well, and thus reduce the percentage by volume of foreign material therein. If other types of treatment of the well fiuid are necessary, 1a treating substance may be added to the operating fluid at its source (not shown), as is well known in the art, and the treating substance maythus be discharged with the'diverted operating fi'uid directly through the bleeder port 'il and the port I5a into the well fluid in the well during operation of the fluid operated pump I'I. Thus, if the well fluid naturally hlas such a high viscosity as to prevent proper operation of the fluid operated pump I'I, a treating agent comprising a thinner, such as, for example, light oil, may be used as the operating iiuid or may be added to the operating fluid, which, when mixed with the well iiuid, causes a material reduc- ,tion of the viscosity of the well iiuid before the same enters the pump unit through the groove lI. Again, if the well fluid in the Well is comprisedlargely of a foam, emulsion, or gas-liquid mixture containing large quantities of gas, a deioaming or `de-emulsifying agent may be added to the operating uid at its source, so that as a portion of the operating fluid is discharged into the well uid through the port I 5a, the defoaming or de-emulsifying agent will act on the foam or emulsion comprising the well iiuid to break the same, thus permitting liquid substantially free of gas to enter the pump unit through the grooveII. It is to be noted that in practicing all of these'methods of treating the Well fluid, the treatment may be carried on continuously during thev operation of the fluid operated pump unit I'l, which is an important feature of my invention. Obviously, if at any time during operation of the uid operated pump unit I'I it is desired to discontinue the treatment of the well iiuidin the well, relative rotation of the production tubing .I4 `and the power tubing I6 may be used to move the port |50, out of registry with the groove ia, thus sealing closed the port I5a.

Figs. 9 and l0 show an alternative form of l pump intake valve construction comprising an upper slide valve device 86 adapted to be substituted for the upper poppet valve device 55 of Fig. o. This embodiment also'contemplates the substitution of a lower slide valve device (not shown) for the lower poppetvalve device 65 of Fig, 4, but as 'the lower slide valve device is of the same construction as the upper slide valve device S-ibut inverted in position, only the Vupper slide i--valve devicegwill be'described in detail.

The upper slide valve device 80 includes a valve cage Il la, of the same general construction as the upper valve cage 4l, but having a depending sleeve portion 8l of smaller diameter than the .diameter of the lower portion of the upper valve cage 4|, the sleeve portion 8| being of such a diameter that it telescopes into the upper end 82 of the liner 35a, forming a Huid-tight sliding t therewith. Provided in the upper end 82 of the liner 35a are intake ports 83 adapted to be disposed below the lower end of the sleeve portion 8| when the liner 36a is in its lower position, and adapted to be closed by the sleeve portion 8l when the liner is moved upwardly to its upper position. The liner 36a is moved between upper and lower positions, as described hereinabove in connection with the operation of the liner 36, and, as will be appreciated, when the liner 36a is in its lower position, as shown in Figs. 9 and l0, the upper slide valve device 80 will be open to permit well iluid to iiow into the upper end of the liner through the intake ports 83, and at the same time the lower slide valve device (not shown) will be closed, and when the upper slide valve device is closed, by upward movement of the liner 35a, the lower slide valve device will be opened. The construction of the upper slide valve device 80 is somewhat simpler than the construction of the upper poppet valve device 55, requiring less parts, but the operation is substantially the same.

Although I have shown and described a preferred embodiment of my invention, it will be understood that I do not intend to be limited thereby but intend to be aiorded the full protection of the following claims.

I claim as my invention:

1. In a pump for use in a well, the combination of: a pump cylinder having heads closing each end thereof; a pump piston in said cylinder; an upper piston rod connected to said pump piston and extending upwardly through said upper head; means for reciprocating said upper piston rod to reciprocate said piston; a lower piston rod connected to said piston and extending downwardly through said lower head and therebelow; a relatively thin sleeve, closed at the bottom and surrounding said lower piston rod projecting below said lower head; and a relatively heavy sleeve rigidly secured relative to said lower head and surrounding said thin sleeve.

2. In a device of the character described, the combination of: a pump cylinder; a cylinder liner in said pump cylinder and adapted to move axially therein, there being a longitudinal iiuid passage between said cylinder and said liner; a pump piston slidably disposed in said cylinder liner; a sleeve member rigidly positioned relative to said pump cylinder and telescoping into said cylinder liner, said cylinder liner having port means adapted to be closed by said sleeve member when said liner is in an upper position and open when said liner is in a lower position, said port means when open communicating between said passage and the interior of said liner; and frictional means between said piston and said liner for moving said liner between said upper and lower positions in response to movement of said pump piston to alternately open and close said port means.

3. In a well pump, the combination of: an upper head member having an upper discharge passage communicating between the lower end of said head member and the exterior thereof; a pump cylinder having its upper end secured to the lower end of said upper head member; a lower head member secured tothe lower Vend of saidV pump cylinder and having a lower discharge passage communicating between the upper end of said lower headmember andthe exterior thereof, and having an inlet passage extending longitudinally therethrough; means in each of said discharge passages; an axiallymovable cylinder liner in said pump cylinder and spaced therefrom to provide an inlet space therebetween communicating with said inletv passage, said liner being axially movable from a i'lrstposition in which said space communicates with the interior of the upper end of said liner to a second position in which said space communicates with the interior of the lower end of said liner; a pump piston in and frictionally engaging said liner; andmeans for reciprocating said pump piston, said liner moving between said positions in response to axial movement of said pump piston and .byvreason of said `frictional engagement between said liner and said piston.

4. Ina well pump, the combination of: an upper head member having any upper discharge passage communicating between the lower end of said head member and the exterior thereof; a

pump cylinder having its upper end secured to the4 lower end of said upper head member; a lowerl head member secured to the lower end of said pump cylinder and having a lower discharge pas-y of, and having an inlet passage extending longitudinally therethrough; outwardly opening valve means in each of said discharge passages; an upper tubular valve member extending downwardly from said upper head member; a lower tubular valve member extending upwardly from said lower head member; an axially movable cylinder liner in said pump cylinder and spaced therefrom to provide an inlet space therebetween communicating with said inlet passage, said liner being axially movable from an upper position in which it telescopes over said upper Valve member to a lower position in which it telescopes over said lower Valve member; a pump piston in and frictionally engaging said liner; and means for reciprocating said pump piston, said liner moving between said positions in response to axial movepassage communicating between the upper end of said lower head member and the exterior thereof, and having an inlet passage extending longitudinally therethrough; outwardly opening valve means in each of said discharge passages; an axially movable cylinder liner in said pump cylinder and spaced therefrom to provide an inlet space therebetween communicating with said inlet passage, said liner being axially movable from a rst position in which said space communicates with the interior of the upper end of said liner 'to a second position in which said space communicates with'the interior of the lower end of said liner; a pump piston in and frictionally engaging said liner; an upper piston rod secured to `said pump piston and extending upwardly Y.

outwardly opening valveA through said upper head member; and a lower piston rod-secured to said piston and 4 extending downwardly through said lower head member, said liner moving between said positions in'respense to axial movement of said pump piston by means of said frictional engagement between said liner and said piston.

6. In a well pump, the combination of: an upper head member having an upper discharge passage communicating between the lower end of said head member and the exterior thereof; a pump cylinder having its upper end secured to the lower end of said upper head member; a lower head member secured tothe lower end of said pump cylinder and having a lower discharge passage communicating between the upper end of said lower head member and the exterior thereof,- and having an inlet passage extending longitudinally therethrough; outwardly opening valve means in each of said discharge passages; an upper tubular valve member extending downwardly from said upper head member; an upper annular valve seat carried by said upper tubular member; a lower tubular valve member extending upwardly from said lower head member; a lower annular valve seat carried by said lower tubular member; an axially movable cylinder liner in said pump cylinder and spaced therefrom to provide an inlet space therebetween communicating with said inlet passage, said liner being axially movable from an upper position in which it telescopes over said upper valve 4member to a lower position in which it telescopes over Asaid lower valve member, said liner having an annular valve member-at each end thereof, said valve membersv being adapted to alternately engage said valve seats in seating relation; a pump piston in and frictionally engaging said liner; and means for reciprocating ,said pump piston, said liner moving between said positions in response to axiall movement of said pump piston and by reason of said frictional engagement between said liner and said piston.

'7. In a Well pump, the combination of a pump cylinder; an upper head closing the upper end of said cylinder; a lower head closing the lower end of said cylinder, said lower head having a longitudinal uid passage therein; a pump piston in said cylinder; an uppervpiston rod connected to said pump piston and extending upwardly through said upper head; means for reciprocating said lupper piston rod to reciprocate said piston; a lower piston rod connected to said piston and extending downwardly through said lower head and therebelow; sleeve means adapted'to enclose the lower end of said lower piston rod andadapted to be secured to said lower head, said sleeve means having a uid port therein adapted to communicate with said longitudinal passage; and means for insuring alignment of said port and passage when said sleeve means is connected to said lower head.

CLARENCE J. COBERLY.

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