US2933043A - Well pump - Google Patents

Description

April 19, 1960 E. c. FURRER 2,933,043

WELL PUMP Filed May 26, 1955 4 Sheets-Sheet 2 INVENTOR. mrg C .gwner 66 BY Mwdaya ATTORNEYS April 19, 1960 E. c. FURRER 2,933,043

WELLPUMP Filed llay 26, 1955 4 Sheets-Sheet 5 IN V EN TOR. 4 merg zwrer A TT O12 NEYS April 19; 1960 E. c. FURRER 2,933,043

WELL. PUMP Filed May 25, 1955 4 Sheets-Sheet 4 inited States Patent WELL PUMP Emery C. Furrer, near Frankfort, Ill.

Application May 26, 1955, Serial No. 511,315

12 Claims. (Cl. 10S-46) This invention relates to improvements in well pumping apparatus, and particularly to such apparatus for use in oil wells.

One object of the invention is to provide an improved pumping apparatus for use in an oil well for pumping oil from the well which comprises a pump and a pump actuating motor that are lowered into a well casing within pumping range of the oil therein and which motor is actuated by a column of oil under pressure, the pressure being supplied by a source of power at the surface. The

, pumping apparatus in the well comprises a pump which is actuated by a reciprocating, huid-pressure-aetuated motor, and both are suspended within the well casing at or near the bottom of the well by two pipe lines, one of which lines conveys oil from a power source at the surface for actuating the uid actuated motor which operates the oil pump, and the other of which receives the oil from the pump as well as the exhaust oil from the motor and delivers it from the well. A portion of the oil recovered from the well is used as the pressure uid for actuating the `pump motor within the well during the operation of the apparatus.

Another object of the invention relates to the provision of a reciprocal motor which is actuatable by fluid pressure and which eiects actuation of a pump, the motor mechanism comprising a piston to which a pump plunger is connected for actuation, the reciprocal piston of the motor being provided -with a shiftable sleeve which delivers pressure lluid selectively to pressure chambers in the pump casing at the ends of the piston for effecting actuation of the piston, and whichsleeve is `shiftable within the piston during the terminal portion of each stroke thereof for cushioning the terminal portions of the strokes and for reversing the direction of operation of the piston.

Still another object of the invention is to'provide a novel reciprocating motor which is actuated solely by a continuous ow of fluid into the motor.

A further object of the invention is the provision of a new and improved reciprocating motor which is actuated by a single pressure uid attachment to the motor with a means within said motor to reverse the uid ilow to effect the reciprocal movement of the motor.

A still further object of the invention is to provide a novel compact reciprocal pump that will pump fluid upwardly onboth the upward and downward stroke of the pump piston.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, when taken in connection with the accompanying drawings, disclose a preferred embodiment thereof.

In the drawings:

Figure 1 is a broken elevational view of a pumping apparatus embodying the invention in position in the casing of an oil well;

Fig. 2 is an enlarged vertical section on line 2--2 of Fig. 1 illustrating theV uid motor and pump;

Fig. 3 is a plan view of the fluid motor and pump casing as viewed on line 3-3 of Fig. 2;

assauts Patented Apr. 19, 1960 vice Fig. 4 is a vhorizontal sectional view taken on line 4-4 of Fig. 2. and illustrating the two chambers of the pump and the two oil delivery ducts or passages communicating therewith;

Fig. 5 is a broken vertical sectional View taken on line 5-5 of Fig. 4;

Fig. 6 is a transverse sectional view of the motor piston taken on line 6 6 of Fig. 2 as viewed in the direction of the arrows;

Fig. 7 is a horizontal sectional view of the motor piston taken on line 7-7 of Fig. 2;

Fig. 8 is a vertical sectional view in the form of a development taken along the lines 8 8 of Figs. 6 and 7 to illustrate in a single view the relation of the sleeve valve of the motor piston to the intake duct of the actuating pressure uid line and the exhaust line;

Figs. 9, 10, and 1l are broken vertical developed sectional views of the uid motor during final positions of the up-stroke of the piston showing the path of iiow of pressure uid to the lower pressure chamber below the piston and the paths for the exhaust of iluid from the upper pressure chamber;

Fig. 12 is a similar View showing the .relationship of the piston, sleeve valve and parts at the end of the upstroke;

Fig; 13 is a view similar to Figs. 9-12 but showing the sleeve valve actuated from the position of Fig. 12 to a reverse position for directing actuating fluid above the piston to effectuate the down-stroke thereof; and

Fig. 14 is a horizontal sectional view of the sleeve valve keying means taken on line 14--14 of Fig. 2.

Generally, one embodiment of the invention consists of a pressure and discharge means A, a motor B and a pump C (Fig. 1). When iluid pressure is applied from the uid and discharge means A to the motor B, the pump C, through a common connection, will be actuated to pump fluid upwardly. The fluid pumped upwardly by pump C will return up through motor Bs discharge systern and then up through the discharge means of iiuid pressure and discharge means A.

In Figure 1, the improved pumping apparatus is illustrated in operative position within a casing 14 of a well. In said figure, an electrical motor 15 is shown for operating a pump 16 which forces oil thro-ugh a pipe 1'7 down into the well, and the pipe 17 is connected to the upper end of a iiuid motor casing 18. To the lower end of the casing 1S is connected a pump casing 19 from which into casing 18 the .pump discharges oil which passes from the .upper end of casing 18 into a delivery pipe 21 which conveys the oil to a tank 2?. at the surface. vFrorn this tank 22 the pump 16 draws oil through pipe 23 which is lforced under pressure into the pipe 17. The pipe 21 is of greater diameter than pipe 17 inasmuch as the pressure fluid which .passes down through pipe 17 to actuate the fluid motor which activates the pump, is exhausted into the pipe 2.1 which also carries the ground oil or petroleum discharged from the pump.

In Fig. 1, a pipe section 2,4 is shown extending from the lower end of the pump casing 19 and is proivded with a sieve 25 at the lower end for excluding extraneous substances from the petroleum or ground oil drawn into the pipe by the suction of the pump in casing 19. Actually the ground oil in the well may be at a level substantially above the sieve 2.5, in fact the normal level of the oil (petroleum) in the well may be at such height as to immerse the casing sections 18 and 19 or partially By the operation of the electrical motor 15, the pump 16 is actuated to draw oil from the tank 22 and force it down the pressure pipe 17. Normally both pipes 17 and 21 will be filled with oil and the columns of oil in the pipes, being of substantially equal height, will exert a similar pressure per square inch at the lower ends. In other words, the two columns of oil will be in balance, normally, and pump 16 need supply oil to the line 17 only ata suitable pressure for actuating the pump motor within the well. Thus, if the per square inch pressure ofthe two columns of `oil in the pipe lines 17 and 21. is 1,000v lbs., for example, the pump 16 should deliver oil to line 17 at from 1,000 to 1,200 lbs. per square inch for procuring ehicient operation of the pump motor within the well and the dischargeof` oil from the exhaust line 21. It `will be appreciated that where the well is deeper and the static pressure of the two columns of oil in lines 17 and 21 are greater, increased pressure of oil delivered to the line 17 by pump 16 may be required.

As shown inl Fig. 2 and Fig. 8, the casing 18 has an upper header 26 and a common lower header 27. This forms an upper casing chamber 23. The pressure oil line 17 and oil discharge line 21 are rigidly secured' to header 26. Within upper casing chamber 2S is slidably mounted a motorV piston 29, having piston rings 30. Secured at the upper end of this -motor piston are an oil pressuresleeve'31 and an oil discharge sleeve 32. As shown in Fig. 8, these sleeves are slidable through header 26 and pipes 17 and 21. Communicating with pressure sleeve 31 is a pressure passage 33 which extends longitudinally within'motor piston 29. Communicating with discharge sleeve 32 isa discharge passage 34 which extendsv longitudinally within motor piston 29. Also within motor piston 29 isa valve passage 35 which is eccentric to the axis of piston 29, extends completelyl through motorpiston 29 and is parallel with pressure passage 33 and discharge passage 34. Pressure passage 33 isconnected with valve passage 35 at 36, whereas discharge passage34 is connected with valve passage 35 at 37 and 33;. Reciprocally mounted within valve passage-35 is avalve sleeve 39. This valve sleeve has fixedly mounted at either end two ange stops 41 and y42. As will be explained later, ange stop 42 is keyed'so as to prevent rotation of'sleeve 39 with' respect to motor piston 29. Valvesleeve 39 has a partition 43 dividing the valve sleeve 39 into upper and lower sleeve chambers 44 and 45. The upper sleeve chamber 44 has a pressure port 46, a discharge port 47 and a discharge bypass port 48. On the outer surface and adjacent the upper end of valve sleeve 39 is a discharge bypass recess 49. The lower valve sleeve chamber 45` has a pressure port 51, a discharge port 52 and a'discharge Y bypass port 53. On its outer surface and adjacent the lowerv end ofl valve sle'e've 39 'is a discharge reces`s1-54. As can be seen, the motor piston, 29y divides the upper casing chamber 28 into an upper motor chamberV 55 and a lower motor chamber 56. The upper' header 26 has a recess 57 in its lower surface, and the common header 27 has a similar recess 50 in its upper surface. These recesses 57, 50 are employed'to accommodate the ends of valve sleeve 39, and their function will be explained later.

Viewing Fig. 8, the motor piston 29 is shown inits midposition with fluid under pressure coming through pressure passage 33 into lower sleeve chamber 4S and then into lower motor chamber 56. In this position, valve sleeve 39 will be kept in its uppermost position by duid pressure applied to partition 43 insleeve 39. In

this position, fluidunder pressure will be forced into thelower motor chamber, vand fluid will be forced from upper motor chamber yS through upper sleeve chamber 44, port 47 and into discharge passage 34. As aresult', uid pressure appliedthrough pipeAV 7'an'd pressurepas'- sage 33 will` force motor piston 29 upwardly solong'as to. header 26. This movement continuesby virtue of pressure port 51 being open, with the discharge from upper motor chamber 55 going through upper bypass port 48 through port 47 and then upwardly through discharge passage 34. As can be seen, as motor piston 29 continues its movement upwardly, the pressure passage through port 51 and the discharge through bypass port 48 are decreasing.

When the motor piston 29" in its upward movement reaches a position-1 as shown inf-Fig. lllthefpressure fluid going into lower motor chamber 56 continues its ow through port 51', although" the amount'of iiowv has been greatly decreased.y by partition .43;substantially blocking outlet 36. On the other hand, the discharge from upper motor chamber 55 then goes solely through discharge bypass recess 49, since bypass port 48 has at this point been fullycoveredby motor. piston. duetol its upward travel.

By virtue of the above conditions, the motori piston: 29 will continue its. travelv upwardly untilreachingthe position, shown iny Fig. 1l. At this proint,iiuicl` discharge from upper sleeve chamber 44 isV completely. blocked, with pressure fluid entering through a small opening in port A46. Consequently, the pressure in the upper sleeve chamber 44 is much greater than the pressure in sleeve chamber 45, since lower motor chamber 56, receiving iluid through a small` opening inA port. 51, can discharge its tluid through'` lower discharge bypass recess 54.-` Due to thisg-.and also a venturi actioncaused .by rapid iluid ow into' lower sleeve chamberAS; the :valve sleeve 39 wil-l be lowered` tothe position as shownzinFig. 12.-

'lny the: position. as shown` in Fig. 1-2,.which1V is reached due .to the. action disclosed in` the. previous paragraph. the u'idfzpressre .from pressure passage 33 .willfthenf enter uppensleeve chamber 44 only-through. a small opening in upper. pressure port 46.-V Since' theupperssleeve.chamber 44. at this timey has no discharge,y theivalvesleeve 39 will continue its movement downwardrelative-to motor piston 29 .because of` uid pressurel upon partition-43,. until it reachesa position as shownimFig'.VVV 13.

Whenthe valve sleeve39 reachesthe position. as .shown in Fig. 13, theziluid pressure through pressure passage 33 will bereceived solely by uppermotor chamber'SS. This will-' causemotor piston129 to move downwardly;` rlhis force'rcausing motor piston 29.tomove downwardly will forceY thee iluid in lower motor. chamber 56 upwardly through lower sleeve 'chamber 45,; pti-H252` and; upwardly tlnfoughJ dischargepassage 34.v

Asf-can be: seen, the motori piston 2.9-willlcontinue its downward travel` until valvesle'eve 39` engagesr'ecess. At this point, the'ow offpressure iluidv through pressure passagef33 will be reversed upwardly by .the same sequence of events whichv have beenfpreviously .described vrigidly connected to motor'lpiston29`. Connecting pipe fcommunicates with discharge passage 34 through conmeeting passage v60v (.Figs.. Z-.and 7).y As shown in Fig. 14', stoplnge 42,!mountedfon valvesleeve 39, ist` keyed to connecting pipe 58 by virtue of keying recess-59 inl a laterally extended portion of the'ngeslidably engaging tlie'pipje.l This',` ofcourse, will prvent 'rotati of valve' slevef39iandfwill"irsureitslpro f Casing-reforms 'a tower eas p y with common header 27 at one endiandf at Athe other Vfendi.. f Connsctingrod 58 f werendlto a puhinpiston 63'. ThepilInppistoa 63I consists' of a"circular"body'portionl'with'upper piston plate- 6,5 and a ,lower piston ,platef The plates 655 and 66A are secured tothegcirciilarbo'dyportioriV 65 through soniesuitable means such lbbl't'sY 67. A Secured between plates 65 and circular portion *are* assaoas gaskets 68 made of leather or some other suitable material. As can be seen in Fig. 2, connecting pipe 58 is rigidly secured to upper plate 65 by a threaded connection. Similarly secured to plate 66 is a pump pipe 69 which is slidable through an aperture in header 62 having sealing rings 70, and enters into pipe 24 giving access to the lluid to be pumped upwardly through sieve 25. The interior of the pump piston consists of an upper piston chamber 71 and a lower piston chamber 72. 'Extending between these two chambers are piston passages 73 and 74. Within each of these passages are two check valves 75, 76, and 77, 7S, respectively. The placement of these check valves form an intermediate piston chamber 79 in passage 73 and an intermediate piston chamber 81 in passage 74. Pump piston 63 divides lower casing chamber 61 into upper pump chamber 82 and lower chamber 83. Intermediate piston chamber 79 is connected to a laterally extending pump passage 84 which is in turn connected to a downwardly extending pump passage 85 (Fig. 4). Passage 85, as shown in Fig. 5, extends through piston plate 66, thus affording a direct communication between intermediate piston chamber 79 and lower pump chamber S3. intermediate chamber S1 is connected to a laterally extending pump passage 86 (Fig. 4) which is in turn connected to an upwardly extending pump passage 87. Pump passage 87, as shown in Fig. 5, extends upwardly through plate 65 and, consequently, affords a di rect communication between upper pump chamber 82 and intermediate piston chamber 81.

In the operation of the pump, the connecting pipe 58 is given a reciprocating motion by the operation of the motor, as described above. This motion in turn is communicated directly to the pump piston 63, because connecting pipe 5S is rigidly connected to pump piston 63. As the pump piston travels upwardly from the position shown in Fig. 2, the fluid in upper pump chamber 82 is forced downwardly through passages 87 and 86 and into intermediate chamber 81. The pressurel of the fluid in intermediate chamber 8i will hold check valve 78 closed and, consequently, the fluid will travel upwardly through check valve 77, upper piston chamber 71, connecting pipe 58, then through discharge passage 34 and eventually into tank 22. The pressure from the fluid going through upper piston chamber 71 will hold check valve`75 closed.

4At the same time that fluid is being forced in this manner from upper piston chamber 82 upwardly through connecting pipe 58, lower pump chamber 83 is enlarging and thus drawing fluid downwardly from intermediate chamber 79 by way of passages 84 and S5, Since check valves 75 and 78 are held closed due to the fluid being drawn from upper pump chamber 82 into connecting pipe 58, the drawing of fluid into lower pump chamber 83 will open check valve 76 and draw the iluid in pumping pipe 69 (and pipe 24) through lower piston chamber 72, past check valve 76, through passages 84 and 85 and into lower pump chamber 83. Thus it is seen when the pump piston travels upwardly two actions occur simultaneously. Fluid in upper pump chamber 82 is pumped up through connecting pipe 58 and fluid in pumping pipe 69 is drawn into lower pump chamber S3.

When motor piston 29 reverses its travel and moves downwardly due to the action of valve sleeve 39 is previously described, pump piston 63 will also reverse its travel and. move downwardly. When this occurs, lower pump chamber 83 will be made smaller and consequently fluid will be forced from pump chamber 83 through passages 85 and 84 into intermediate piston chamber 79. -At this point, the fluid pressure will force check valve 76 closed and will travel upwardly through check valve 75, upper piston chamber 7l, into connecting pipe 58 and eventually through discharge passage 34 into tank 22. `This tluid flow will cause check valve 77 to stay closed. At the same time that this iluid action is occurring, upper pump chamber 82 is enlarging, causing the lliuid in pumping pipe 69 (and pipe 24) to be drawn upwardly through lower piston chamber 72, past check valve 78 (check valve 76 being forced closed), into intermediate piston chamber 81. Since check valve 77 is forced closed the fluid will then travel through passages 86, 87 and into upper pumping chamber 82. Thus it is seen that on the downward stroke of pump piston 63, iluid in lower pump chamber 83 is forced up through connecting pipe 58, while lluid in pipes 69 and 24 is drawn into upper pump chamber 82. Hence on both upward and downward strokes of pump piston 63, fluid is pumped from one of the pump chambers upwardly through connecting pipe 58 while simultaneously the fluid in pumping pipe 69 is drawn into the other pumping chamber. Thus is disclosed a highly efcient double-acting pump.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and the scope of the invention or sacrificing all of its material advantages, the form hereinbeforc described being merely a preferred embodiment thereof.

I claim:

l. A well pump, comprising an upper casing chamber and `a lower casing chamber; a fluid motor in said upper casing chamber comprising a motor piston having a fluid pressure passage, a fluid discharge passage, and a single valve passage therein communicating with both said pressure and discharge passages, and a unitary sleeve valve mounted for limited reciprocal movement in said valve passage to control the direction of flow of lluid delivered under pressure from said pressure passage alternately to opposite ends of said motor piston and also from the others of said opposite ends alternately to said discharge passage to actuate said piston for reciprocal movement within said upper chamber; a reciprocating, double-acting pump within said lower casing chamber comprising a pump piston having Huid passages therethrough, ball valves controlling the ilow of iluid through said passages, and a pumping pipe connected to said pump piston for receiving iluid to be pumped upwardly, and a connecting pipe interconnecting said pump piston and said motor piston for reciprocating the pump piston and conducting the fluid discharge of said pump to said fluid discharge passage of said motor.

2. A Well pump, comprising a casing divided into upper and lower casing chambers, a motor in said upper casing chamber comprising a motor piston actuated for reciprocal movement by fluid pressure, a fluid pressure supply pipe and a liuid discharge pipe connected to the upper end of said casing, iiuid discharge means extending through said motor piston and communicating with said discharge pipe, a reciprocating, double-acting pump in said lower casing chamber, said pump having a pumping pipe for receiving `fluid to be pumped upwardly, and a connecting pipe connecting said pump to said motor piston for re- Y ciprocal movement, said connecting pipe connecting the discharge of said pump to said uid discharge means.

3. A well pump, comprising a casing divided into an upper and a lower casing chamber, a motor in said upper casing chamber comprising a piston actuated for reciprocal movement by lluid pressure, a fluid pressure passage and a fluid discharge passage within said piston, a lluid pressure means connected to said iluid pressure passage and a lluid discharge means connected to said `tluid discharge passage, a single sleeve valve mounted for reciprocal movement relative to said motor piston to alternately direct said lluid pressure to the upper and lower surfaces of said motor piston and connect said fluid discharge passage With opposite ends of said upper casing chamber to automatically effect continuous reciprocating movement of said motor piston, a reciprocal pump in said lower chamber, said pump having a pumping pipe for receiving fluid to be pumped upwardly, and a connecting pipe connecting said pump to said motor piston and connecting the discharge of said pump -to said `fluid discharge .passage of said motrl piston.-

' `4. yA wellfpumpas setiforthin claim 3, wherein said sleeve valve is'vm'ountedfor `reciproca-l movementin .said motor pistoneccentric to theaxis thereof.

5. Awallpump, comprisingaLcasinghaving an upper casingchamber ywith anupperheader at one endend -a common .headerat the other end, a'motor in said upper chamber ycomprising ya f motor piston dividing said .upper casing chamber into an upper' and a llower motor'chamber,luid `pressure meansfor applyingilnid pressure and fluid discharge ymeans for-discharging said fl'iuid pressure mountedfon said upper header -to actuate said motor-pis ton for reciprocalmovement'within said upper casing chamber, a fluid pressure Vpassage and a fluid discharge passagewithin said motorl piston, means for establishing communication between said fluid pressure: passage and said fluid pressure means and said fluid discharge passage and'said fluid discharge'means, a valve passage extending within saidmotor piston and communicating with said pressurepassage at one point and communicatingwith said discharge passage at two points, a valve' sleeve mounted for reciprocal movement relative to said motor piston in said valve passage, a sleeve partition dividing said sleeve into an upper anda lower sleeve chamber, an upper pressure port, an upper discharge port andan upper discharge bypass means in said upper sleeve chamber, `a. lower pressure port, a lower discharge port and a lower discharge bypass rneansin said lower sleeve chamber, said pressure ports communicating with said pressurel passage, said discharge ports communicating with said `discharge passages and said discharge bypasses, and'means com.

and said fluid discharge means in such a sequence, due to Vthe application of pressure by said fluid kpressure means andv the abutment of said sleeve with the ends of said upper casing chamber, as to automatically reverse the flow ofthe pressure iluid from one motor chamber to the other.

6. A well pump as set forth in claim 5, wherein said upper dischargeV bypass means comprises an. upper-bypass port in said sleeve and an upper bypass recess on the eX- terior of said sleeve, and. said lower discharge bypass means comprises a lower bypass port in said sleeve and a lowerbypass recess on the exterior of said sleeve. v

7. A Well pump as set forth in claim5, wherein said upper discharge bypass means comprises an upper bypass port in the upper sleeve chamber that in certain positions communicates with the upper motor chamber, and an upper bypass recess on the exterior of said sleeve that in certain positions alords communication between said upper motor chamber and said discharge passage, while the lower discharge bypass means comprises a lower bypass port in theflower sleeve chamber that in certain positions communicates with the lower motor chamber, and ay lower bypass'recess on theexterior of said sleeve that in certain positions affords communication between said lower motor chamber and said discharge passage.

8. well pump asset forth in claim 5, wherein said 'casing has a lower casing chamber with said common header at one end and a lower header at the other end, a

pump in said lower casing chamber comprising a pump piston dividingsaid-lower casing chamber into upper and lower pump chambers, said pump piston having an upper and lower piston chamber, said pump piston being rigidly connected with saidmotor 'piston by a connecting pipe slidably Vmounted vin said common header'and connecting lsaidupper pumpchamber with said tluid discharge pas- -ing chambers,..lone vofifsaid :intermediate pumping charnbers being in commumcation-with said upper pumping chamber andthe other intermediate `pumping: ,Chamber being inv communication with; said lower` pumping chamber.

9. AIn a wellpurnp, a ,uzd .motorv comprising a casing chamber, a, motor. pistonmounted for reciprocahmove, ment within ysaid'chamber and .dividing saidf casing; chamf berV into upper, and; lower; motor chambers, fluid `p :essure means and lfluddischargemeans, and a valve sleeve mountedfor reciprocal movement in said .motor piston, said ,valve sleeve having afpressureport, a discharge port and .a @discharge bypass means, saidgpressure port being in registry with said uid Pressure means in certain positions, said discharge port being in registrywith said iluid dischargerneansin certain positions, and said discharge bypass means-affording communicationghetween one of said Amotor chambers and ,saiddischarge bypass means in Certain p0sitions, said fluid pressure means actuating said sleeve so asto reverse the Yflow of said pressure means from` one end ,of said motorpiston to the other to effect a reciprocal movement of said motor piston.

10. A fluid motoras forth in claim 9, wherein said discharge bypass rmcflns comprises a bypass vrecess on the exterior of said, sleeve `and .a bypass port through said sleeve.

11. Foruse ina well bore, a, pump comprising a casing adapted to be Ydisposed adjacent4 the lower end of said bore, means dividing the Ainterior of said casing into an upper motor chamber and a `lower pump chamber, a doubleactingypurnpdisposed in` said pump chamber, a motor piston disposediin` saidmotor chamber and having a fluid supply passage, a separateuid ,discharge passage, and a` valve passage extending therethrough, with said valve passage interconnecting said supply and dischargepassages,r a pipe interconnecting said pump :and said piston for imparting movement of the latter tosaid pump and transmitting fluid discharge from said pump to said discharge passage, a supply pipe extending down said bore-and connected at its lower end to the :upper end of said casing for supplying fluid under pressure, means interconnecting said supply pipe'and said supply passage, a discharge pipe of larger diameter than said supply pipe extending down said bore and connected at its lower end to theupper end of saidgcasing, means interconnectingy said1discharge; pipe and, said discharge passage, anda sleeve valve mounted in said valve passage to block communication;` between said ysupply and. discharge passages andreciprocable -to Ialternately rstdirect iluid from said supply passage into said motor chamber below said lpiston and to connect saidmotor chamber above said piston with saiddischargepassage and, second, to direct fluid from -said supply passage into said motor chamber abovesaid piston and connect said motor cham.- ber below said piston withsaid discharge passage, whereby to elect reciprocal movement of said piston.

12. A pump according to claim l1, wherein said Vsleeve valve is provided with, a central partition of slightly less *Y thickness vthan the vertical dimension of the interconnection betweensaidguid supply and valve passages, and ports in said valve directly above and below ysaid partition,; whereby aVe'nturi;action is effected duringeach relativereciprocation between said valve andsaid piston to insure Ireversal of movement of the latter.4

f References Citedin theile `of this patentv UNITED STA7l` `PAl`ENTS i

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