US2311157A

US2311157A - Fluid operated pump with built-in governor

Info

Publication number: US2311157A
Application number: US385874A
Authority: US
Inventors: Clarence J Coberly
Original assignee: ROKO CORP
Current assignee: ROKO Corp
Priority date: 1941-03-29
Filing date: 1941-03-29
Publication date: 1943-02-16
Anticipated expiration: 1960-02-16

Description

6 Sheets-Sheet l Feb. 16, 1943. c. .1. coBERLY FLUID OPERATED PUMP WITH BUILT-IN GOVERNOR Filed March 29, 1941 Feb. 16, 1943.

C. J. COBERLY FLUID OPERATED PUMP WITH BUILT-IN GOVERNOR Filed Marchs, 1941 34 v wwwa,

, 6 Sheets-Sheet 2 n n n CLARE/VCE d. CoE/uy C, J. coBERLY Feb. 16, 1943.

FLUID OPERATED PUMP WITH BUILT-IN GOVERNOR s sheets-'sheet s Filed March 29, 1941 Feb. 16., V19.43. Q J, COBERLY l 2,311,157

FLUID OPERATED PUMP WITH BUILT-IN GOVERNOR Filed March 29, 1941 e sheets-sheet 4 /N VEN TOIQ/ CLARE/veg d. Cosa/@Ly 6 Sheets-Sheet 5 w 6 www@ W Feb. 16, 1943. c. 1. colar-:RLY

FLUID OPERATED PUMP WITH BUILT-IN GOVERNOR Filed Marchy 29, 1941 Feb. 16, 1943. c; J, COBERLY 2,311,157

FLUID OPERATED PUMP WITH BUILT-IN GOVERNOR *ib m. al? nu: F//e NITED STATES PATENT ori-lcs FLUID OPERATED PUMP WITH BUILT-1N GOVERNOR Clarence J. Coberly, Los Angeles, Calif., assignor 'to Roko Corporation, Reno, Nev., a corporation of Nevada Application March 29, 1941, Serial No. 385,874

24 Claims. (Cl. 121-157) My invention relates to a uid operated motor pump piston compresses the gas in the pocket and-more particularly, to such a device having a and strikes solid well iluid in the pump cylinder. reciprocating motor piston in which the rate of Such fluid operated pumps are ordinarily operreciprocation of the motor piston is automaticalated at relatively great depths in oil wells, and, 1y main-tamed below a predetermined maximum 5 accordingly, a large volume of operating huid regardless of changes in the working load on under high pressure is coniined in the supply such piston. tubing between the well pumping mechanism In certain respects my invention is an improveand the operating pump n the Surface 0f the ment on the device disclosed in my earlier Pat; ground which supplies the Operating 111111 Due ent No. 2,134,174, issued October 25, 1938, to to the compressibility of this large volume of opwhich reference ishereby made. erating fluid, and due to the `expansion of the Alhough my invention is of particular utilityM supply tubing under the high pressure of the in the oil industry in combination with a pumpt operating fluid exerted thereon, a large amount -for pumping oil from a well, and -for the purof energy is stored in the system under these pose of illustration is described in connection operating conditions. If for any reason the with such use, it will be apparent to those skilled pumping load on the iluid operated pump dein the art that it is susceptible of other and difcreases. due to the presence of Ysasin the well lferent uses, and, consequently, I do not intend liquid, failure of the pump valve to seat properly,

to be limited to the particular use described. or due to any other cause, the operating iluid In the oil industry it is common practice to use in the supply tubing expands as a result of the rea uld operated pump inwpumping oil from a lease of the energy of compressionvstored therein, well, such a pump generally comprising a couand the supply tubing contracts due to the repled motor and pump combination set in the well lease of the energy of expansion stored therein, at the level from which it is desired to pumpthe causing an increased rate of ow of operating oil. In such a pumping device, the motor. is norduid to the iiuid operated pump. This condition mally actuated by admitting operating fluid, such occurs even when a. positive displacement suras oil, under relatively high pressurey alternately face pump is used on the groundgsurface to conto opposite ends of a motor piston to reciprocate vey operating iluid downwardly through the supthesame, the reciprocation of the motor piston ply tubing, and such surface pump is operated being suitably communicated to a pump piston at a constant speed. As will be appreciated, an in the pump end of the device so as t0 Dump oil increase in the rate of flow of operating uid from the well. In order to conduct operating delivered through the supply tubing will cause iiuid alternately to opposite ends ofthe motor the fluid operated pump to run at increased piston, a main valve mechanism is ordinarily speed, which becomes excessive if thenrate of ow employed, such as is shown in my said Patent of operating fluid is substantially increased, as is No. 2,134,174. It is a primary object of my pres true under the conditions described'. Thus, when ent invention to provide such a mainvalve mechthe pump load decreases, the iiuid operated anism in an improved form as described hereinpump will run at excessive speed until the pump afterload is.raised by removing`\the gas from the pump In pumping oil .from a well, the well oil ire- 40 orfotherwise rectifying the condition. The pump quently contains mixed therewith or in solution may thus race for a portion of a stroke or for-a therein Varying quantities 0f natural gas pronumber of successive strokes, and in any event duced from the well together with the oil, the the pump will operate at excessive speed until quantity of such gas depending upon local condiall of the energy of compression stored in the options or particular wells. Furthermore, it is @rating fluid and energy of expansion stored in common experience in the oil industry that the the supply tubing are released, or until the pump quantity .of gas in the oil of a particular well load is again applied tothe fluid operated pump. frequently varies within wide limits at different When a uid operated pump runs at excessive times during production from the well. Since speed, it may be very\harmful -to certain parts displacement type pumps are 'most commonly 50 of the pumping equipment. This is particularly used to pump oil, considerable difiiculty has been true when the pump cylinder isonly partially experienced, particularly in pumps of the uid L'filled with well iiuid, in which case the pump operated type` as described above, with gas piston will move at extremely high speed durpockets forming' in the pump cylinder, thus reing the rst part ci' its stroke while it is comducing materially the pumping load until the pressing the gas therein and will then strike the liquid therein while moving at high velocity. This introduces a hydraulic shock load which results in abnormal stresses on the parts of the pump and may cause considerable damage in the form of excessive wear, scoring, seizing, or breakage of the parts. To prevent uneven operation of the pumping equipment, and to prevent such racing, Various expedients have been used, one of which is to provide a flow governor in the operating uid supply line which will reduce the :dow of operating fluid to the fluid operated motor in response to a reduction in pump load, such a device being shown in my Patent No. 2,119,736, issued on June '7, 1938, to which reference is hereby made for the purpose of illustration. Such flow governors are separate articles of to changes in the rate of uid ilow for regulating the rate of such fluid ilow.

equipment and'must necessarily be attached in the operating iluid supply line at a point above the pumping equipment, thus increasing the cost of the pumping installationand, because the governor must perforce be located at a point relatively remote 'from' the motor cylinder, increasing the hazards of the pump racing due to theynormal time lag in the operation of the iiow govrectly into my main valve mechanism, so as to obviate theprovision of a separate ow governor, which is another 'object of the invention.

A further object of my invention is to provide l a fluid ow governor mechanism in a well and immediately adjacent the motor cylinder of a fluid operated pumpfor controlling the ow of operating uid to the motor cylinder, so as to reduce the time lag normally incident to the use of a fluid flow governor with such pumping mechanism.

It is a further object of my invention to provide a main valve mechanism for a iluid operated pump, adapted to convey operating fluid alternately to opposite ends of the motor piston of the pump, and which is adapted to maintain the flow of operating fluid to the motor cylinder below a predetermined maximum rate when the pumping load on the pump drops below a predetermined value so as to prevent racing nof the pistons thereof.

Another object of my invention is to` provide a main valve mechanism forl a uid operated pump, adapted to convey operating fluid alternately to opposite ends of the motor piston, and to control the discharge of spent operating uid from the motor piston, and which is adapted to maintain such discharge of spent operating fluid below a predetermined maximum when the pumping load on the pump drops below a predetermined value so as to prevent racing of the pistons of the device. f'

Another object of my invention is to provide a novel type of movable main valve for a fluid operated pump, the movement of which has novel characteristics providing smoother and more efiicient operation of the valve.

As my invention may be used in connection with hydraulic equipment other than pumps such as are described hereinabove, still another object of my invention isv to' provide in a valve device -for directing a uid flow a mechanism responsive tion, carried downwardly from the lower end of Fig. 2.

Fig. 4 is a cross-sectional view taken on the line 4-4 of Fig. 1.

Fig. 5 is a cross-sectional view taken on the line 5-5 of Fig. 1.

Fig. 6 is a cross-sectional view taken on the,

line 6-6 of Fig. 1. o

Fig. 7 is a cross-sectional viewl taken on the line 1-1' of Fig. 1. a

Fig. 8 i-s a cross-sectional view-taken on the line 8-8 of Fig. 1.

Fig. 9 is al cross-sectional view taken on the line 9-9 of Fig. 1.

n Fig. 10 is a cross-sectional view taken on the line lIll-Ill of Fig. 1.

Fig. 11 is a cross-sectional 'view taken on the y line II-JII of Fig. l.

Fig. 12 is a cross-sectional view taken on the line I2-I2 ofFig. 1.

Fig. 13 is a view showing the outer surface of the main valve of my invention projected onto a vertical plane.

Fig. 14 is a verticalsectional view of my invention, showing the main valve in one position of vention, showing the main valve in another position of operation.

Fig. 19 is a vertical sectional view ofmy in I vention, showing the main valve in another position of operation. v l

Fig. 20 is a vertical sectional view of my invention, showing the main valve in another position of operation.

Fig. 21 is afgraph showing the operation of my invention under normal operating conditions.

Fig. 22 is a graph showing the operation of my invention when the pump cylinder contains only about 30% solid'fluid.

Fig. 23 is a graph showing the operation of my invention when the pump cylinder contains no solid iluid but gas.

Referring to the drawings, Figs.,1, 2, and 3 show a fluid operated pump 25 having an upper fitting 26 by which the iluid operated pump is secured to the lower end of a fluid supply tubing 21 by which operating fluid under relatively high pressure is delivered to the motor section of the fluid operated pump. The fitting 26 has an internally threaded portion 28 adapted to receive a circular channel 3| from a major bore 32 axially formedin the lower portion of the valve body 29. Substantially intermediate between the ends of the minor bore 3|) i`s an upper circular channel 33 which intersectsthe upper ends lof,primary ,Y

fluid passages 34, vas bestshownin Fig. 4, such uidpassages extending within the wall of the valve body 29 to the lower end thereof. Spaced below the channel 3| in the major bore 32 is a fluted annular channel 35 the utes of which intersect with the upper ends of secondary fluid passages 36, as best. shown in Fig. 46, each of which Aextends longitudinally to the lower end of the valve body 29, the secondary iluid passages 36 being spaced between the primary :fluid passages 34.

Connecting the circular channel 3| with the exterior of the valve body 29 is a motor discharge port 31, and an upper 'valve discharge port 38 is provided in the wall of the valve body 29 to connect `between the exterior thereof and the interior of the major bore 32. Extending upwardly from the bottom of the valve body 29 is a valve exhaust passages 39, best shown in Figs. l, 11 and l2, the exhaust passage being disposed between two of the secondary i'luid passages 36. Connecting the upper end of the valve exhaust passage 39 with the exterior of the valve body 29 is a lower valve exhaustV port 40.

The lower end of the valve body 29 is provided with a threaded portion 4| to which is threaded the upper end of a, motor cylinder 42. The motor cylinder 42 is provided at its upper end with a counterbored axial chamber 43 in which is disposed a plug body 44 held in Huid-tight engagement with the lower end of the valve body 29 and in duid-tight engagement with the upper end of a motor cylinder liner 45 when the parts are assembled as shown in Fig. l. Mounted in the upper part of the plug body 44 is a valve liner 46 having an upper sleeve portion 41 extendingl upwardly within the major bore 32 of the valve body 29 to a point a short distance below the uted annular channel 35, there being an annular space 48 formed within the major bore 32 around the uppersleeve portion 41 of the valve liner 46. The

,valve liner 46 is provided with an axial bore 49 therethrough, in which is formed an annular channel 50 communicating through a plurality of upper liner ports 5| with the annular space 48 with the parts in the position shown inuFig. 1. Below the channel 50 in the bore 49 of the valve liner 41 is an annular channel 52 which communicates through a plurality of intermediate liner ports 53 with the annular space 48. A shoulder or collar 54 is'formed on the valve liner 46 in a position to rest upon the upper end of the plug body 44, the outer periphery of the collar 54 making a fluid-tight fit with the lower end of the major portion 63 thereof andhas an externahsurface 64 which forms a substantially fluid-.tight sliding lit in the minor bore 30- of the valve body 29. The major portion 63 of the valve member 60 has an external surface 65 which forms a substantially fluid-tight sliding fit withgthe major bore 32 of the valve body 29, the major portion of the valve member extending downwardly into the annular space 48 between the major bore and the external surface of the valve sleeve 41. The uppermost part of the minor portion 6I of the valve member 60 is reduced in diameter to provide an annular channel 65a therearound in which are upper inlet -ports 66, and in the major portion 63 are lower inlet ports 61 whichcommunicate with an annular channel 88 formed on the exterior of the valve member. Formed on the external surface of the minor. portion 6| of the valve member 68 is an annular channel 69 which, when the valve member is in the position shown in Fig. 1,

-nel 65a and consequently with each of the upper inlet ports 66 isa-short vertical channel 1| formed in the outer surface of the minor portion 6| of the Valve'member 60, the channels 1| being of varying lengths. Similarly formed, in the outer surface of the minor portion I6| are a set of vertical -channels 12 communicating with the annular channel 69, and formed in the external surface of the major portion 63 ofthe -valve member 68 are vertical channels 13 also communieating with the annular channel 69. Likewise, vertical channels 14 are formed in the major portion 63 of the valve member 60 and communicate with the lower inlet ports 61. The channels comprising each of the sets of vertical channels 1|, 12, 13, and 14 are ofl varying lengths, as illustrated in Fig. 13, for a purpose to be de- `scribed hereinafter.

Formed in the bore of the major portion 63 of the valve member 68 is an annular channel 15 communicating with the lower inlet ports 61. Also formed in the major portion 63 is a helical passage 16 of relatively small cross-sectional area which communicates between the annular chan` nel 15 and a wide annular channel 11 therebelow. In between the threads of the lower end of the helical passage 16 is an upper governing port 18 which communicates with a circular chanthe major bore 32. In the bore 49 of the valve liner 46, below the annular channel 52, is formed a lower annular channel 55 which communicates through a plurality of lower liner ports 56 in the wall of the valve liner 46 with an annular space 61 surrounding a lower reduced portion 58 of the collar 54, the space 51 communicating separated by an annular shoulder 62 from a lower maior portion 63. The minor .portion 46| oi the 'valve member '60 is of a smaller diameter than v75 nel 19 formed on the exterior surface of the major portion 63 of the valve member 6D. At the lower end of the wide annular channel 11 is 'a circular channel 8B which communicates with the annular/space 48 below the valve member 6|) through valve passages 8|, and whichv also communicates through a lower governing port 62 with a circular channel 83 formed in the outer surface of the major portion 63 of the valve member. Formed in the outer surface of the upper sleeve portion 41 of the valve liner 46, above the upper liner port 5|,is an annular channel 84, and communicating between one of the secondary passages 36 and the interior, Yof the major bore 32 of the valve body 29 is anouter governing port |65. f

Slidable Within the bore of the valve liner 46 in huid-tight relation therewith, and movable within the bore of the valve member 60 in spaced relation thereto, is a pilot rod 86, the lower end of which is connected to the upper end of a motor piston 81- adapted to be reciprocated within the motor cylinder liner 45 ofthe motor cyllnder 42. A cavity 88 formed in the lower end of the plug body 44 constitutes a continuation of the bore of the cylinder liner 45, and is provided with an inwardly tapered wall portion 89 having an annular channel 90 formed therein which intersects the lower vends of a plurality of vertical passages 92 formed in the plug body 44, each of the vertical passages 92 being axially aligned with the primary passages 34, thel upper end of each of the vertical passages 92 registering with the lower end of one of the primary passages 34. The cavity 88 above the annular channel 90 forms a dashpot chamber for holding a body of iiuid to stop the upward movement of the power piston 81 with a cushioning eect, as is well known in the art. As will be noted, the secondary iiuid passages 36, which lead downwardly from the lutedannular channel 35, connect with lluid passages 93 having the form of grooves in the external face' of the plug body 44, the lower end thereof communicating with the axial chamber 43.

The lower end of the motor cylinder 42 is connected by threads 95 to an intermediate plug 96 which has an upwardly extending tubular projection 91, the upper end of which engages the lower end -98 of the cylinder liner 45 in fluidtight engagement. In the upper end of the tubular projection 91 is a dashpot cavity 99 for a purpose similar to thatl of the cavity 88, the upper end of the dashpot cavity 99 communicating through lower motor' cylinder ports |00 with an annular space around the tubular projectionv 91 and within the motorcylinder 42'the upper end of which communicates through longitudinal passages |02 formed between the motor cylinder 42 and the cylinder liner 45 with the lower f end of the axial chamber 43.

The lower portion of the intermediate plug 196 is provided with external threads |04, to which is threaded the upper end Hof a pump cylinder |05 having a cylinder liner |06 therein, similarly to the motor cylinder 42 with its liner 45v therein, vertical longitudinal'passages |01 being provided between the pump cylinder and the cylinder liner. Disposed between the lower end of the intermediate plug 96 and the upper end-ofthe cylinder liner |06 of the pump cylinder |05 is an upper pump valve device |08 which includes an upper discharge valve H0 and an upper inlet valve III. The upper discharge valve ||0 'is housed in a chamber I I2 formed in the lower end of the intermediate plug 96, which communicates through upper discharge passages ||3 with the exterio' of the intermediate plug 96, the upper discharge valve including spring-held ball members ||4 adapted to open vupwardly to permit a now of duid from the upper end of the cylinder liner |06 therethrough and through the upper discharge passages I3, but preventing a reverse ilow. The upper inlet valve is disposed in a chamber ||5 provided in a valve cage I I6, and includIes spring-held ball members ||1adapted to open downwardly to permit a flow of fluid into the upper end of the cylinder liner |06 through an upper inlet passage ||8 formed in a valve ring mediate plug 96 and the upper end of the valve cage ||6.

An intermediate piston rod |2| extends downwardly from the lower end of the motor piston 81 through the intermediate plug 96 and the upper-.pump .valve device |08, and has its lower end connectedto a pump piston |22, the pump piston being reciprocable in the cylinder liner |06..

The lower end of the pump cylinder |05 is provided with internal threads |23 by which the same is connected to a lower plug |24. Between the upper end of the lower plug |24 andthe lower end of the cylinder liner |06 is disposed a lower pump valve device |25 which includes a lower discharge valve |26 and "a lower inlet valve |21, the lower discharge and inlet valves |26 and |21, respectively, being similar in construction to the upper discharge and inlet valves ||0 and respectively. The lower discharge valve |26 communicates with the lower end oi! the cylinder liner |06 and with a lower discharge passage |28 formed in the lower plug |24, which in turn communicates with the exterior of the plug. The lower inlet valve |21 communicates between the interior of the lower end of thel cylinder liner |06 and with a space |29 between the exterior of the lower pump valve device |25 and the pump' cylinder |05, the space in turn communicating with vertical inlet passages |30 formed in the lower plug |24.

The lower end'of the lower plug |24 is connected by external threads to a lower inlet tting |3| provided with a lower conical end |32 in which an inlet opening |33 is formed. The conical end |32 of the inlet fitting |3| is adaptedl to seat in an inlet seat |34 carried by a bottom hole fitting |35 suitably threaded to the lower end of a production tubing|36 which. extendsV upwardly through the well to the surface of the ground and is adapted to convey pumped uid therethrough. I prefer to connect to the' lower end of the fitting |35 a liner |41 having a' lower Aopen end and which may-extend as far as desired below the tting into the well, although it will beunderstood that this liner may be omitted if desired.

Threaded into the lower end of the lower plug 24 is a tubular closure member |38 having its lower end closed. A lower piston rod |39 is suitably connected to the lower end of the pump piston |22 and extends downwardly through the lower pump valve device |25 and the lower plug |24 into the interior of the tubular closure member |38. As will lbe noted, the pilot rod 86, the

motorpiston 61, the intermediate piston rod |2|, the'pumpl piston |22, and the lower piston rod |39 are provided `with' axially aligned and communicating longitudinal passages |4|, |42, |43, |44, and |45,'respectively, so as to provide fluid 'communication therethrough with the interior of the tubular closure member |38 so asto` balance the fluid pressure on the upper and lower ends of the rods.v

As shown in Figs. 1 and 4, the upper end of the pllot'rod 86 is provided with a plurality of circumferentially spaced\\upper vertical channels |46, and also formed therebelow inthe external surface of the pilot rod is a set of lower vertical channels |48, as best'shown in Figs. 1 and l2,

||9 disposed between the lower end of the interinater, alternately to opposite ends of the motor ypiston 81, causing the same to reciprocate in the cylinder liner 45. Reciprocation of the motor piston 81 is communicated through the intermediate piston rod |2| to the pump piston |22,

and into the upper end of the cylinder liner |06 above th'e pump piston |22 as the same moves downwardly. During such'downward movement of the pump piston |22, fluid in the cylinder liner 86 therebelow is expelled therefrom through the lower discharge valve |26 and the lower discharge passage i 28 directly into the production tubing |33, from whence it ows upwardly therethrough to the surface of the ground. During downward movement of the pump piston |22, obviously, the upper discharge valve H8 and the lower inlet valve |21 will both remain closed. When the motor piston 81 starts its upward stroke from the position shown in Fig. 17 to'that shown in Fig. 2,

^ it carries with it the pump piston |22, and well through the lower inlet valve |21 into the lower end of the cylinder liner |88 below the pump piston |22, andat the same time iiuid in the cylinder liner |86 above the pump piston i 22 will be expelled therefrom through the upper discharge valve ili and the upper discharge passages ||3 into the production tubing |38, from whence it ilows upwardly to the surface of the ground. Thus, it will be understood that a substantially continuous flow of pumped fluid is created in the production tubing |38 during reciprocationof the pump piston |22.

The operation of the main valve member 88 will now be described, but as it operates dierently underdiierent well conditions its normal operation under normal well conditions will first be described. By normal well conditions I mean the normal situation when the pump cylinder liner |88 is iilled with substantially solid iluid, i. e., when there is little or no gas mixed with the liquid entering the cylinder liner |83 from th'e well.

With the parts in the position shown in Fig. 1, the main valve member 80 is in substantially Yits. uppermost position, and the motor and pump pistons 81 and |22, respectively, and the pilot rod 85 have reached substantially the upper end of their upward strokes. are aligned with the iluted annular channel and fullyopen, and there is an unrestricted ilow of operating uid from th'e interior of the valve body 29 through the lower inlet ports 61, the

4fluted annular channel 35, the secondary iluid 69, and the motor discharge port 31,l and during upward 'movement of the motor piston spent The lower inlet ports 81 i operating uid thereabove may thus exhaust` into the production tubing.

As the pilot rod 86 has substantially reached the upper end of its upward stroke, as shown in Fig. 1, the lower vertical channels |48 therein span the lower annular channel 55 and the annu- `lar channel 52 to open the annular space i8 beneath the main valve member to discharge pressure through the intermediate liner ports 53,

thev annular channel 52, the lower vertical channels I48, the lower annular channel 55, the lower liner ports 456, the annular space 51, the opening 59, the exhaust passage 39,' and .the lower valve exhaust port 44|). Since the pressure exerted by the operating fluid on'the upper end of the minor portion 62 of the valvemember 6U is substantially greater than the pressure exerted on the lower end of the major portion 63 of the valve member by the discharge pressure in the production tubing |36, the valve member, as shown in Fig. 1, is about to move downwardly. The valve member 8l) then moves downwardly at a relatively high rate of speed to the position shown in Fig. 14, at which time the downward speed thereof is materially reduced, the initial phase of the downward movement of the valve member being graphically represented by the portion |58 of the chart illustrates in Fig. 21. v

As the valve member 88 moves downwardly from the position shown in Fig. 1 to the position shown in Fig. 14, the lower inlet ports 81 therein pass out of registry with the luted annular channel 35, thus shutting oii the ow of operating iiuid to the lower end of the power piston 81. Similarly, the annular channel 83 formed on the exterior of the valve member 88 passes out ofv registry with the circular channel 33, thus shutting off the exhaust ow of spent operating iuid member'in communication with the discharge pressure through the valve passages 8|, the circular channel 80, the wide annular channel 11, the helical passage 16, the annular channel 15, the lower inlet ports 61, the annular channel 88, and the upper valve discharge port 38. Since y the helical passage 16 -is relatively long and is of restricted cross-sectional area, iluid from the space 48 below the valve member 60 exhausts slowly, and, consequently, the valve member 60 moves slowly until it reaches the position shown in Fig. 15, this slow phase of its movement being graphically illustrated by the portion |5| of the chart shown in Fig. 21.

During the relatively slow downward movement of the valvemember 6U between the positions shown in Figs. 14 and 15, the ow of operating fluid to the upper end of the motor piston 81 is started and increased gradually to prevent iluid shock which would otherwise occur if the full volume of operating uid were suddenly delivered to the motor piston. This gradual increase in the volume of operating uid delivered to the upper end of the motor piston 31 is controlled by the varying-length vertical channels 1 1|, shown in Fig. 13, which, as downward movement of the valve member 60 progresses, successively open restricted uid communication between the operating fluid and the circular channel 33, and, consequently, the upper end of the motor piston. Consequently, the :motor piston 81 accelerates gradually in its initial downward movement, as graphically indicated by the portion |60 of the chart of Fig. 21. Similarly, Aduring this same portion of movement of the valve member 60, the lower side oi' the motor piston 81 is gradually opened to exhaust pressure lby the varying-length vertical channels 13 successively registering with the fluted annular channel 35. It will thus be understood that during the first portion of this slow phase of the downward movement of the valve member 60 the flow of operating fluid to the upper end of the motor piston 81 is metered by the vertical channels 1|, and the discharge from below the motor piston is simultaneously metered by the vertical channels 13.

As soon as theA vertical channels 1| start to register with the upper circular channel 33 and operating fluid flows therethrough to the upper end of the motor piston 81 to start the downstroke thereof, the pilot rod 86 also moves downwardly to take the lower vertical channels |48 therein out of registryV with the annular chan-v nel 52, as shown in Fig. 15', thus shutting oil all communication between the annular channel 52 and the lower annular channel 55 during the remainder of the downstroke of the valve :member 60. However, upon the valve member 60 reaching the position shown inA Fig. l5, the circular channel 19 registers with the outer governing port |65, and the lower end of the valve member 60 is thus additionally opened to discharge pressure through the upper .governing port 18, the outer governing port |65, the secondary passage 36, the fiuted annular channel 35, the vertical varying-length channels 13, the

shallow annular channel 60, and the motor discharge port 31. Since the cross-sectional area. of this fluid path is large relative to that of the path through the helical passage 16, the valve member 60 increases its downward rate of movement until it reaches the position shown in Fig. 16, this phase of downward travel of the valve member being graphically represented by the portion |52 of the chart shown in Fig. 21. As will be noted from Fig. 2l, however, the downward speed of the valve member 60 during the portion |52 is not as great as the speed of its initial travel represented by the portion |50, which is due to the difference in lengths and cross-sectional areas of the passages. and ports through which the uid exhausts from the annular space 48 in the two portions of travel of the valve member, respectively.

It is to be noted that on the downstroke of the valve member 60, although the vertical channels 1| initially register with the circular channel 33 simultaneously with the initial registry of the vertical channels 13 with the fluted annu7 lar channel 35 so as to simultaneously throttle the initial flow of operating fluid to the upper end of the motor piston 81 and the initial discharge of spent operating nuid from below the motor piston, the annular channel 65a, on the upper end of the valve member 60 opens to the circular channel 33 before the annular channel 69 opens to the fluted annular channel 35, due to the fact that the vertical channels 1| are shorter than the vertical channels 13, as best shown in Fig. 13.

As soon as the annular channel 65a registers with the circular channel 33, a substantially uninterrupted flow of operating fluid can iiow to the upper end of the motor piston 81, and thus the vertical channels 13 continue to throttle the ow of spent operating fluid from beneath the motor piston after a free flow of operating fluid is permitted to ow to the upper end of the motor piston. This continued throttling of the spent operating fluid through the vertical channels 13 only continues, of course, until the valve member 60 has moved downwardly suiliciently to permit the annular channel 69 to register directly with the iluted annular channel 35, at which time, as shown in Fig. 16, the circular channel 33 is fully open to operating fluid through the annular channel 65a and the upper inlet ports 66, and the iluted annular channel 35 is fully open to discharge pressure through the annular channel 69 and the motor discharge port 31.

When the valve member 60 reaches the position shown in Fig. 16, it will be noted that the circular channel 19 has passed downwardly out of registry with the outer governing port |65, and, consequently, uid from the annular space 48 must again exhaust through the helical passage 16 and the upper valve discharge port 38, which, due to the relatively small cross-sectional area of this path of flow, produces a small amount of end movement of the valve member at the same rate `as represented by the portion |5| of the graph of Fig. 21. This slow end action of the valve member is designed to protect it against undesirable hammering, and for the purpose of simplification has been omitted from the graphs of Figs. 21 and 22, although it will be understood that it will be present under all conditions of operation where the valve member completes its stroke. So far as a general understanding of the action of the valve member 60 is concerned. however, the valve member may be regarded as remaining substantially in the position shown in Fig. 16 until it starts its upstroke, this stationary phase of the valve members action being shown by the portion |53 of the chart of Fig. 2l. As will be noted, when the valve member 60 reaches the position shown in Fig. 16, operating fluid unrestrictedly flows to the upper end of the motor piston 81 from the upper fitting 26 through the annular channel 65a and the upper inlet ports 65, through the circular channel 33, the primary fluid passages 34, the passages 02, and through the annular channel 00 into the upper end of the cylinder liner 46. In this position, also, the lower end of the motor piston 81 is unrestrictedly opened to exhaust pressure through the'lower motor cylinder ports |00, the longitudinal passages |02, the axial vchamber 43, the uid passages 93, the secondary fluid passages 36, the fluted annular channel 35, the annular channel 69, and the motor discharge -port 31. The motor piston 81 then completes its downward stroke, graphically represented by the portion |54 of the chart of Fig. 2l, reaching the piston shown in Fig. 17.

When the motor piston 81 land pilot rod 86 approach their lower position, shown in Fig. 17,

the upper longitudinal channels |46 in the pilot rod register with the annular channel 50 in the upper sleeve portion 41 of the valve liner 46, so as to open fluid communication between the operating fluid in the supply pipe 21 and the lower end of the space 48 through the annular channel 50, the upper liner ports 5|, the wide annular channel 11, the circularchannel 80. and the valve passages 8|. Since the cross-sectional area of the lower end of the valve member 60 is greater than that of its upper end, and since the valve member 66 is so designed that when in this position the total upward force exerted by the operating fluid thereon exceeds the total downward force exerted thereon by the operating uid and the discharge pressure, the admission of operating fluid beneath the valve member 60 .causes the same to move upwardly at a relatively high rate of speed to the position shown in Fig. 18, this first phase of the upward movement of the valve mem-ber being graphically illustrated by the portion |55 of the chart shown in Fig. 21. It will be understood that the area ratio between the pressure ends of the valve member 60 'which includes the areas open to exhaust can be altered to. vary the action of the valve member as desired.

'Upon its arrival at the position shown in Fig. 18, the lower end of the valve member 66 has just closed the upper liner ports but considerably previous thereto the annular channel has opened iiuid communication between the operating uid and the annular space 48 through the helical passage 16, the wide annular channel 11, the circular channel 86, and the valve passages 8l. Thus, closure of the upper liner ports 5| does not stop the upward movement of the valve member 66, but due to the restricted crosssectional area of the helical passage 16 the ow of operating uid to the underside of the valve member is retarded, and, consequently, the valve member moves relatively slowly to the position shown in Fig, 19, this,second phase of the upward movement of the valve member being graphically illustrated by the portion |56'of the chart of Fig. 21. It is -to be noted that the distance the valve member 66 must travel on its upstroke during which the lower inlet ports 61 are out of communication with the upper valve discharge port 38 and with the operating uid above the valve liner 46 is very small. This is an important feature, as occasionally the pilot rod 86 may move upwardly slightly so as to move the upper longitudinal channels |46 therein out of registry with the annular channel 50, which stops the cw of operating uid to the lower end of the annular space 48 through the upper liner ports 5|, and if the annular channel 15 has not device by providing only a small travel of the` valve member 60 during which the lower inlet ports 61 are out of iiuid communication with either the upper valve discharge port 38 or the operating fluid above the valve liner 46. If the pilot, rod 86 moves upwardly slightly so as to move the upper longitudinal channels |46 out of registry with the annular channel 56 while the lower inlet ports 61 are still in iiuid comfmunication withl the upper valve discharge 38 through the annularchannel 68, since uid communication still existsl between the lower end of -the space 48 and the discharge pressure through the helical passage 16, the uid from below the valve member will slowly exhaust therethrough, permitting the valve member to move downwardly to the lower end'of its stroke, following which it will again start its upstroke, and since by the time the valve member reaches the lower movedthe motor piston to the lower endof its stroke, a normal upstroke of the valve member can be performed. Similarly, if the pilot rod moves upwardly slightly so as to move the upper longitudinal channels |46 out of registery with the annular channel 50 after the upper end of the annular channel 15 has moved above the upper end of the valve liner 46, operating fluid is then in direct communication with the lower end of the valve member through the helical passage 16, and it can complete its upstroke at the rate indicated by the portion |5| of the graph of Fig. 21. The same feature to reduce the tendency of the valve member 66 to stop on dead Vcenter is provided in the downstroke of the valve member when the lower inlet ports 61 move doWnwardly out of communication above the valve liner 46 with the operating uid and before the vannular channel 68 registers with the upper valve discharge port 38, the tendency of the valve member to stop on dead center being thus reduced to a minimum.

During the relatively slow upward movement of the valve member 60 between the positions shown in Figs. 18 and 19, the ow of operating finid to the lower end of the motor piston 81 is started and increased gradually to prevent uid shock which would otherwise occur if the full volume of operating uid were suddenly delivered to the motor piston, 'Ihis gradual increase in the volume of operating fluid delivered to the lower end of the motor piston 81 is con trolled by the varying-length vertical channels 14, best shown in Fig.v 13, which progressively register with the uted annular channel. 35, to meter the flow therethrough as described above in connection with the vertical channels 1| upon the downstroke of the valve member. Consequently, the motor piston 81 accelerates gradually in its initial upward movement, as graphically represented by the portion |61 of the chart-shown in Fig. 21. Simultaneously with the initial registry of the vertical channels 14 with the uted annular channel 35,the vertical channels 12 register with the circular channel 33 to gradualinitial admission of operating fluid to the lower end 'of its stroke operating'iiuid will again have 7B end of the motor piston. Since the vertical channels 14 are shorter than the vertical channels 12, on the upstroke of the valve member 6U the annular channel 69 fully registers with the circular channel 33 to permit uninterrupted discharge from the upper end of the motor piston 81 while the vertical channels 14 are still throttling the ow of. operating fluid therethrough to the fluted annular channel 35 and to the lower end of the motor piston.

When the valve member 60 reaches the position shown in Fig. 19, the circular channel 83 and the lower governing port 82 register with the outer governing port |65, and the lower end of the valve member 60 is thus additionally opened to operating fluid through the lower inlet ports 61, the uted annular channel 35, the secondary passage 36, the outer governing port L65, the lower governing port 82, and the valve passage 8|, and thereupon the valve member continues its upward movement at an increased rate of speed until it reaches the position shown in Fig. 20. This phase of upward movement of the valve lrn'ember 60 is graphically illustrated by the portion |51 of the chart shown in Fig. 2l.

When the valve member 60 reaches the position shown in Fig. 20, the upper end of the motor piston 81 is unrestrictedly opened to discharge pressure from the primary fluid passages 34, the circular channel 33, the annular channel 69, the circular channel 3|, and the motor discharge port 31. Also, the lower end of the motor piston 81 is unrestrictedly opened to operating iluid through the lower motor cylinder ports |00, the

longitudinal passages |02, the axial chamber 43,l

the fluid passages 93, the secondary uid passages 36, the fiuted annular channel 35, and the lower inlet ports 61. Consequently, from the position shown in Fig. 20 the motor piston 81 moves upwardly to the position shown in Fig. l. When the valve member 60 has moved upwardly to the position shown in Fig. 20, it will be noted that the upper end of the valve member has not yet engaged the fitting 26 and that the annularv channel 83 has just; moved out of registry with the outer governing port |65. Consequently, in this position operating iiuid can still flow to the lower end of the valve member 60 through the helical passage 16, which causes a slight further end movement of the valve member at a reduced rate of speed which is the same as that 4indicated by the portion |56 of Fig. 2l, and which provides a small amount of upward end movement of the valve member similar to the lower end movement thereof described hereinabove. So far as a general understanding of the operation of the valve member 60 is concerned, the valve member may be regarded as remaining substantially stationary in the position shown in Fig. 20, as graphically indicated by the portion |58 of the chart of Fig. 2l, the remaining upward movement of the motor piston being represented by the portion |59 of the chart. When the parts reach the positions shown in Fig. 1, a complete cycle of operation has been completed, and a new cycle starts, as described hereinabove.

In they operation of a iiuid operated pump', such as described herein, it is desirable to maintain the iiow of operating fluid to the motor piston at a substantially uniform rate. If, however, the pump load is suddenly decreased, the rate of ilow of operating fluid normally would increase, as pointed out hereinabove, with an attendant excessive increase in the speed of the motor and pump. To prevent this condition occurring, my invention' includes governing'means adapted to operate in response to a decrease in pump load to maintain the ow of operating uid to the motor piston 81 below a predetermined maximum rate, so `as to prevent undesired acceleration of the moving parts, and the operation of such governing means is now described.

The governing means of my invention' includes the upper and lower governing ports 18 and 82, respectively. and the outer governing port |65 communicating between one of the secondary fluid passages 38 and the annular space 48, as shown in Fig. l0.

When the pump cylinder liner |08 ahead of the pump piston 22 contains only about 30% well liquid and the balance gas, the governing action of my device is as follows: The valve member 60 moves downwardly from the position shown in Fig. 1 to the position shown in Fig. 14 at a rapid rate, this portion of its movement being illustrated graphically by the portion |82! of the chart of Fig. 22, which action is exactly the same as the action thereof shown by the portion |50 of Fig. 21. The valve member 60 then continues its downward movement et a slow rate, this portion of its travel being illustrated by the portion |83 of the chart of Fitz-22, which action is exactly the same as the action thereof shown by the portion |5| of Fig. 21. At the beginning of the slow downward movement of the valve member 60, in which it is in the position shown in Fig. 15, the vertical channels 1| begin to register with the circular channel 33 to permit an initial restricted ilow of operating fluid from the supply pipe 21 to the upper end of the motor piston 81, and simultaneously during this portion of the movement of the valve member 60 the vertical channels 13 successively register with th fiuted annular channel 35 to permit a restricted flow of spent operating fluid to exhaust from below the motor piston 81. After the vertical channels 13 begin to register with the fluted annular channel 35 and the annular channel 65a is fully open to the circular channel 33, the circular channel 19 registers with the outer gov` verning port |65. Since the pump cylinder liner |06 below the pump piston |22 is lled largely with compressible gas, the force needed to move the pump piston downwardly to compress this gas is relatively small compared with the force required to move the pump piston when it is engaging solid liquid, and, consequently, even a restricted ilow of operating iiuid to the upper end of the motor piston 81 is suicient to start the downward movement of the motor and pump pistons at a greater rate of speed than would be the case if the pump piston were engaging solid liquid. The increased rate of speed of this initial downward movement of the motor piston 81 is graphically illustrated by the portion |66 o f the.

chart shown in Fig. 22, which can readily be compared with the initial downward movement of the motor piston under normal conditions by referring to the portion |60 of Fig. 21. Due to this increased initial velocity of the pump piston |22, and due to the i act that the discharge from below the pump piston is throttled by the restricted cross-sectional areas of some of the vertical channels 13 communicating with the iluted annular channel 35, huid pressure quickly builds up in the secondary passages 36, and this rise in iluld pressure is communicated to the lower end of 'the valve member 60 through the outer goveming port |65 and the upper governing port 18,

'which prevents further downward movement of the valve member until the uidgpressure therebelow is reduced, as the valve member is so designed that a predetermined rise in pressure therebelow will stop its continued downward movement, due to the difference in areas of its upper and lower ends, and due to the fact that fluid under such increased pressure is supplied from the secondary passage 36 through the outer governing port to the bottom of the annular space 48 faster than it can exhaust through the helical passage 16. It is also to be noted that the proper relation must be maintained in deesign between the cross-sectional .area of the outer governing port |65, the helical passage 16, the annular channel 19, the port 18, the wide annular channel 11, the annular channel 80, and the parts 8|, as the outer governing port |65 must admit iiuid to the lower end of the valve member 60 faster than the helical ,passage 16 will permit ,it to exhaust through the upper valve discharge port 38.

Thus, the valve member 60. under such operating conditions, will remain stationary, as graphically illustratedrr by the portion |64 of the chart of Fig. 22, and the motor piston 81 will move at slightly increased but controlled velocity,

as indicated by the portion |61 of Fig. 22, until plished in a slightly different manner.

the pump piston strikes solid liquid. When this occurs, the downward rate of movement of the pump piston |22, and the motor piston connected thereto, is materially reduced, and consequently the uid discharge pressure in the secondary passages drops due to the reduction in speed of the pistons, thus allowing the fluid beneath the valve member 68 in the annular space 48 to exhaust into the secondary passages 36 through the outer governing port |65 to permit the valve member to resume its downward movement from the position shown in Fig. to that shown in Fig. 16, which movement is represented by the portion |68 of the graph of Fig. 22, and which is exactly the same as the corresponding valve movement under normal conditions as represented by the portion |52 of the graph of Fig. 21. During the movement of the valve member 60 from the position shown in Fig. 15 to that shown in Fig. 16, the annular channel 69 registers with the uted annular channel 35 to open fully the discharge from the lower end of the pump piston |22. Prior to the governing or metering action through the vertical channels 13, the annular channel 65a has registered with the circular channel 33 to open the upper end of the power piston 81 to operating fluid, as described hereinabove in connection with the operations shown in Fig. 21. As soon as the pump piston |22 hits solid liquid in the pump, the balance of the stroke of the motor piston 81 is at a velocity reduced below normal, as indicated by the portion |69 of the graph of Fig. 22, the change in speed of the piston from high velocity tov low velocity being gradual as the valve member is 'in the throttling or controlling position shown in Fig. 15 when the pump piston strikes solid liquid and the valve has to'open before the piston can assume normal speed under load, which, plus the compression of the gas below the pump piston, tends to round oil? the curve shown in Fig. 22 and make a gradual transition from governed high speed to low speed of the piston. As soon as the valve member 68 reaches the position shown in Fig. 16, it remains substantially stationary until the motor piston 81 completes its downward stroke, this portion of the action of the valve member being represented by the portion ,|1| of the graph of Fig. 22,

The same type of governing action takes place upon the upward movement of the valve member 60, asis shown by Fig. 22, but is accom- When the pump cylinder liner |06 above the pump piston |22 is similarly iilledwith a mixture of gas and iiuid, the upward movement of thevalve member 60 is the same as the upward movement thereof under normal conditions of operation as shown in Fig. 21 until the valve member reaches the position shown in Fig'. 19. When the valve member 60 reaches the position shown in Fig. 19, the upper end of the motor piston 81 is fully open to exhaust pressure by registry of the annularchannel 68 with 4the circular channel 33, but operating iluid is still metered through the vertical channels 14 which have :lust started to register with'the iluted annular channel 36, thus throttling the ow of operating iiuid to the lower endo! the motor piston 81,l as described hereinabove. and the circular channel 88 oi' the lower novernmgport 82 has ,lust registered with the outer governing port |66. As will also be noted fromFlg. 1 9-, the motor piston 81 has started its upward movement, and the vertical channels |46 are out of registry with the annular channel 50. Due to gas in the pump cylinder above the pump piston |22, the iiuid pressure of the operating iluld in the secondary passages 36 remains relatively low as the iiow is throttled through the vertical channels 14 until the pump piston strikes solid liquid, and while the pressure in the secondary passages is thus relatively low, operating uid which 'would be normally supplied to the lower end of the valve member 66 through the helical passage 16 is permitted to 'discharge from the wide annular channel 11 through the lower governing port 82, the circular channel 83, and theouter governing port |65 into the secondary passages 36, thus keeping the full pressure of the operating iuid off the lower end of the valve member 60 which causes it to remain stationary, as illustrated by the portion |12 of the chart of Fig. 22. As the valve member 60 thus hangs up until the pump piston |22 again strikes solid liquid, the ow of operating uid to the lower end of the motor piston 81 is metered through the vertical channels 14 while the valve member remains stationary. As soon V.as the pump piston strikes solid liquid, the iuid pressure inthe secondary passages 36 rises due to a decrease in the throttling action of the vertical channels 14 because of the resulting lower pump piston speed. and, consequently, the discharge of operating iiuid from the lower governing port 82 stops, and operating uid then flows to the lower end of the valve member 60 from the secondary passages 36, causing the valve member 60 to resume its upward movement represented by the portion |13 of the graph shown in Fig. 22. The'upstroke of the motor piston 81 is.

both ends of the pump piston.|22 is the same.

Fig. 23 graphically illustrates the operation of the motor piston 81 and the valve member 60 in the special case when the pump is operating at zero eiiiciency, i. e., when the pump is not pumping any fluid from the well. This curve assumes that the uid operated pump has been operating at zero eiciency for a sumcient length of time so that the stored energy of compression of the operating uid and the stored energy of expansion of the supply tubing have been entirely released, and, therefore, the pistons will operate at the normal number of strokes per minute as determined by the rate of ow` of operating iiuid delivered through the supply tubing to the uid operated pump by the surface pump. This condition of zero emciency may be caused by the upper and lower inlet valves and |21, respectively, becoming cloggedv with foreign material so that they will not unseat, or may be caused by other operating conditions. Under these conditions of operation, the valve member 60 performs its rst two functions, illustrated by the -portions and |8| of the'graph of Fig. 23, normally, as .will be .seen by a comparison with the chart of Fig. 21, but hangs up and remains in the throttling position shown in Fig. 15 and graphically indicated by the portion |82 of Fig. 23 for the remainder of the downstroke of the motor piston 81. 'I'he 'valve member 60 hangs up due to of illustrated in Fig. 22. At the end of the downstroke of the motor piston 8l, the valve member 60 then resumes substantially normal operation for its rst two functions, as graphically indicated by the portions |83 and IM of Fig. 23, on the start of the upstroke of the motor piston, but hangs up in the throttling position shown in Fig. 19 and graphically shown by the portion |85 of Fig. 23 for the balance of'the upstroke of the motor. piston. It will therefore be appreciated that under such conditions of operation the piston motion is almost exactly normal and the energy of the operating'fluid, which would normally be used to operate the uid operated pump to lift well liquid, is all consumed in the throttling action of the valve member 6B. I

It will be appreciated -that the conditions of operation graphically illustrated by Figs. 21,` 22, and 23 are not mutually exclusive or typical, but are merely examples of the operation of my invention-under selected different operating conditions. The movement ofthe valve member 60 under other operating conditions may vary substantially, but in every case will be such as to meter the ow to the motor piston 81 on the upstroke of the valve member and to meter the ow from the motor piston on the downstroke of the valve member, to prevent racing of the pistons. Those skilled in the art will readily understand that the ow governing action'of my valve construction occurs whenever the pump piston |22 strikes gas instead of solid liquid, and that the upward or downward movement of the valve member 60 stops until the pump piston strikes solid liquid, thus providing an automatic throttling action to maintain the ow of operating fluid to the motor piston4 81 below a predetermined maximum rate, thus preventing racing of the pump with the attendant danger of damage to the moving parts. It will thus be apparent that the number of strokes per minute of my pump will be maintained below a predetermined maximum, regardless of the presence of gas in the pump liner |06 and regardless of the amount of such gas, in spite of the ing said valve member at a materially reduced uniform rate of speed from said first point to a second point at which said valve has fully opened said passage; and means for moving said valve member from said second point to said secondary position at a materially increased rate of speed.

2. A valve mechanism for opening a passage adapted to carry a flow of fluid, including: a valve member movable between primary and secondary positions to open said passage at a point intermediate said primary and secondary positions; throttling means associated with said valve member for gradually opening saidpassage as said valve member approaches said point so as to meter the ow of fluid through said throttling means; means for moving said valve member between said point and said' secondary position; and means for maintaining said valve member in said metering position when the rate of flow of fluid through said throttling means tends to rise above a predetermined maximum.

3. A valve mechanism for opening a passage adapted to carry a flow of uid, including: a valve member movable between primary and secondary positions'to open said passage at a point intermediate said primary and secondary positions; throttling means associated with said valve member for gradually opening said passage as said valve member approaches said point so as to meter the ow of uid through said throttling means; means for moving said valve member between said point and said secondary position; and means for stopping said valve member in said metering position when the pressure of said uid in said passage drops below a predetermined minimum and retaining saidl valve member in said metering position until the pressure of said fluid in said passage rises above a predetermined maximum.

4;. A valve mechanism fora fluid motor of the character described having a motor piston operable in a motor cylinder and having a passage for exhausting spent operating fluid from one end of said cylinder, including: a valve member movable between primary and secondary positions to open'said passage at a point intermediate said primary and secondary positions; throttling normal tendency of the pistons to speed up under such circumstances. It will also be appreciated that any sudden increase in the speed of the prime mover in the surface pump supplying the operating fluid will likewise fail to cause vthe piston 81 to race, as any momentary increase in the rate of flow from whatever cause will be governed in the same manner as described hereinabove.

Although I have described my invention as applied to a fluid operated pump, in which it may be used to particular advantage, it is to be understood that my device may be used in. other capacities without departing from the spirit of my invention. Consequently, I do not intend to be limited to the particular lconstruction described, but desire to be afforded the full scope of the following claims.

I claim as my invention: l

l. A valve-mechanism for a uid motor of the character described having a motor piston operable in a motor cylinder and having a passage for supplying operating fluid to one end of said cylinder, including: a valve member movable between primary and secondary-positions to open said passage; means for moving said valve member at a relatively high rate of speed from said primaril position to a first point at'which said valve memmeans associated with said valve member for gradually opening said passage as said valve member approaches said point so as to meter the exhaust ow of spent operating fluid through said throttling means; means for moving said valve member between said second point and said secondary position; and means for stoppingsaid valve member in said metering position when the pressure of said exhausting operating fluid rises above a predetermined maximum and retaining said valve member in said metering position until the pressure of said exhausting operating Il uid drops below a predetermined minimum.

5. A valve mechanism for a fluid motor of the character described having a motor piston operable in a motor cylinder and having a passage for ber is about to open said passage; means for movwith said valve member for gradually opening Y said passage as said valve member moves from said first point to said intermediate point so as to meter the ilow of operating fluid through said passage; means for moving said valve member from said intermediate point to said secondary position at a materially increased rate of speed; and means for maintaining said valve member in said metering position between said iirst point .and said intermediate point when the -rate of flow of operating fluid. through said throttling means tends to rise above a predetermined maximum.

' 6. In a fluid operated motor device, the combination of: a motor cylinder having a motor piston therein: a iluid passage communicating with one end of said motor cylinder; a valve member in the line of said uid passage and movable between primary and secondaryk positions to open fluid communication through said fluid passage; means for' moving said-t valve member between said primary and secondary positions; and means for controlling said movement of said valve member in response to variations .in fluid pressure in 'said fluid passage between said valve member and said motor cylinder.

7. In a iluid operated motor device, the combination of: a motor cylinder having a motor piston therein; a fluid passage communicating with one end of said motor cylinder; a source of operating fluid under pressure; a valve member movable between primary and secondary positions to alternately connect saiduid passage with said operating iluid under relatively high pressure or with a point of discharge at relatively low pressure, said valveimember being of the differential area type having a small face continuously subjected tojthe pressure of said operating iluid and having a large face alternately subjected to the pressure of said operating fluid;

throttling means for metering the flow of fluid through said passage as said valve means apy tions to alternately connect said fluid passage proaches said primary and secondary positions; r

and port means for connecting said iiuid passage .with said large end of said valve member in both of said metering positions.

8. In a fluid operated motor device; the combination of: a motor cylinder having a motor piston therein; a iirst iluid passage communieating lwith one end of said motor cylinder; a sec--l ond fluid passage communicating with the other end of said motor cylinder; a source of operating fluid under pressure; a valve member movable vbetween primary and secondary positions and constructed and arranged so that when in said.

primary position it connects said ilrst fluid passage wlth said operating fluid under relatively high pressure and said second fluid passage with a point of discharge at relatively low pressure, and when in said secondary position it connects said ilrst fluid passage with said point of discharge and connects said second fluid passage with said operating fluid, said valve member being of thedifferential area type having. a small face continuously subjected to the pressureoi' ne end of said motor cylinder; a source of opwith said operating iluid under relatively high pressure or with a-point of discharge at relatively low pressure, said valve member being of the differential area type having a small face continuously subjected to the pressure of said operating fluid and having a large face alternately communicating with said 'operating fluid and said low pressure discharge point through a. restricted iluid flow passage; throttling means for metering the flow of fluid through said passage as said valve means approaches said primary and secondary positions; and port means for connecting said fluid passage with said restricted lflow passage in both of said metering positions.

10. In a fluid operated motor device, the combination of: a motor cylinder having a motor piston therein; a iirst fluid passage communicating with one end of said motor cylinder; a second fluid passage communicating with the other end of said motor cylinder; a source of operating fluid under pressure; a valve member movable between primary and secondary positions and constructed 4and arranged so that when in said primary position it connects said first fluid passage with said operating iluid under relatively high pressure and said second fluid passage with a point of discharge at relatively low pressure, and when in said secondary position it connects said ilrst fluid passage with saidpoint of discharge and connects said second fluid passage with said operating iluid, said valve member being of the differential area type having a Small face continuously subjected to the pressure of said operating fluid and hav-ing a large face alternately communicating with said operating fluid and said low pressure discharge point through a restricted fluid flow passage throttling means for metering the flow of fluid through said passages as said valve means approaches said primary and secondary positions; and port means for connectingone of said uid passages with said restricted flow passage in both of said metering positions.

ll. In a. valve device, the combination of: a housing having an inlet and a discharge port; a `first passage in said housing; a second passage in said housing; valve means in said housing adapted to move between primary and secondary positions so as to alternatively connect said first passage with said inlet and said second passage with said discharge port or to connect said first passage with aid discharge port and said second passage with said inlet; and means for connecting said first passage with said inlet before said second passage is connected with said discharge port. y

12. In a valve device, the combination of: a housing having an inlet and a discharge port; a iirst passage in said housing; a second passage in said housing; valve means in said housing adapted to move between primary and secondary positions so asto alternatively connect said first*-l passage with said inlet and said second passage with said discharge port or to connect said first passage with said discharge port and said second passage with said inlet; means for connecting said ilrst passagewith said inlet before said second passage is connected with said discharge port; and means for connecting said ilrst passage with said discharge portbefo're said second passage is connected to said inlet. y Y

13. In a valve device, the combination of: a

housing having an inlet and a discharge port; a rst fluid passage in said housing; a second fluid passage in said housing; a valve member movable between a primary position in which said valve member connects said iirst passage with said inlet and connects said second passage with said discharge port and a secondary position in which said valve member connects said first passage with said discharge port and connects said second passage with said inlet; throttling means for metering a iiow of fluid through said second passage at is opens to communication with said discharge port through said valve member; and means for causing said valve member to open communication between said first passage and said inlet before it opens communication between said second passage and said discharge port, so that when said valve member is in said metering position communication Will be fully open between said inlet and said iirst passage.

14. In a valve device, the combination of: a housing having an inlet and a discharge port; a first iluid passage in said housing; a second iiuid passage in said housing; a valve .member movable between a primary position in which said valve member connects said rst passage with said inlet and connects said second passage with said discharge port and a secondary position in which said valve member connects said first passage with said discharge port and connects said second passage with said inlet; throttling means for metering a flow oi fluid through said second passage as it opens to communication with said inlet through said valve member; and means for causing said valve member to open communication between said iirst passage and said discharge port before it opens communication between said second passage and said inlet, so that when said valve member is in said metering position communication will be fully open between said discharge port and said first passage.

l5. A valve mechanism for a fluid motor of the character described having a motor piston operable in a motor cylinder and havingy a first passage for supplying operating fluid to one end of said cylinder and a second passage for supplying operating fluid to the other end of said cylinder, including: a valve movable from a primary position to a secondary position to open said first passage, and movable from said secondary position to said lprimary position to open said second passage; means for moving said valve member at a relatively high rate of speed from said primary position to a rst point at which said valve member is about to open saidfirst passage; means for moving said valve member at a materially reduced rate of speed from said first point to a second point at which said valve member has fully opened said first passage; means for moving said valve member from said second point to said secondary position at a materially increased rate of speed; means for moving said valve member at a relatively high rate ofrspeed from said secondary position to a third point at which said valve member is about to open said second passage; means for moving said valve member at a materially reduced rate of speed from said third point to a fourth point at which said valve memberhas fully opened said second passage; andv means for moving said valve member from said fourth point to said primary position at a materiallyincreased rate of speed, to complete a cycle of operation of said valve member.

16. A valve mechanism for opening a passage gaines? adapted to carry a dow of fluid, including: a valve member alternately movable in either of two directions between primary and secondary positions to open said passage at a zone intermediate said primary and secondary positions;

thottling means associated with said valve member for gradually opening said passage as said valve member approaches said zone in either of said directions so as to meter the flow of fluid through said throttling means; and means for maintaining said valve member in said metering position so long as the rate of now of fluid through said throttling means tends torise' above a predetermined maximum.

17. A valve mechanismfor opening a passage adapted to carry a flow of fluid, including: a valve member movable between primary and secondary positions, said valve member opening said passage at aninterinediatezone of movement between said positions; throttling means associated with said valve member for gradually opening said passage as said valve member passes through said zone to meter` the flow of iiuid through said throttling means; and means for maintaining said valve member in said metering position so long as the pressure of fluid in said passage varies from a prescribed value.

18. A valve mechanism for opening a passage adapted to carry a iiow of iiuid, including: a valve member movable between primary and secondary positions, said valve member opening said passage at an intermediate zone of movement between said positions; throttling means associated with said valve member for gradually opening said passage as said valve member passes through said zone to meter the flow of fluid through said throttling means; means for maintaining said valve member in said metering position so long as the pressure of fluid in said passage varies from a prescribed value; and means for completing the movement of said valve member between said positions when the pressure of fluid in said passage returns to said prescribed value.

19. In a fluid operated motor device, the combination of a, motor cylinder having a motor piston therein; a iirst fiuid passage communicating with one end of said motor cylinder; a second iiuid passage communicating with the other end of said motor cylinder; a valve member movable between primary and secondary positions, said valve member when in said primary position opening said rst passage to a source of operating fluid under pressure and said second passage to a low pressure discharge, said valve member when in said secondary position opening said first passage to said discharge and said second passage to said source; means for moving said valve member between said primary and secondary positions; and means for controlling said movement of said valve member in response to variations in uid pressure in one of said fluid passages between said valve member and said motor cylinder.

20. In a valve mechanism for opening a passage adapted to carry a flow of iiuid, including: a source of operating fluid under pressure; a point of discharge at relatively low pressure; a valve member movable between first and second operating positions to alternately connect said fluid passage with said operating fluid under relatively high pressure or with said point of discharge, said valve member being of the difierential area type having a .small face continuously subjected to the pressure of said operating fluid and having a large face alternately subjected to the pressure of said operating fluid; and means for Acontrolling said movement of said valve member in response to variations in lluid pressure in said iluid passage.

21. In a valve mechanism for opening a passage adapted to carry a ilow of uid, including:

a source of operating fluid under pressure; a

point of discharge at relatively low pressure; a valve member movable between first and second operating positions to alternately connect said uid passage with said operating uid under relatively high pressure or with said point of discharge, said valve member being of the diierential area type having a small face continuously subjected to the pressure of said operating fluid and having a large face alternately subjected to the pressure of said operating uid; and port means for connecting said uidpassage with said large face of said valve member as said valve member approaches each of said positions.

22. In a valve device, the combination of: a housing having an inlet port and a discharge port; a rst passage in said housing; a second passage in said housing; valve means in said housing adapted to move between primary and secondary positions so as to alternately connect said iirst passage with said inlet port and said second 'passage with said discharge port or to connect said iirst passage with said discharge port and said second passage with said inlet port, said valve means being so constructed and arranged that it connects said first passage with said inlet port before said second passage is connected with said discharge Jport; throttling means for alternately gradually opening said second passage to said inlet port or said discharge port to meter a ow of fluid through said second passage; and means for controlling the operation of said valve member in response to variations in iiuid pressure in said second passage.

23. In a valve device, the combination of: a valve housing having an inlet adapted to be connected to' a source of operating iiuid under relatively high pressure, and having rst and second exhaust ports adapted to be connected to a point at relatively low pressure; 'a valve member in said housing and of the differential area type having a small end adapted to be subjected to the iluid pressure in said inlet and a large end adapted to be opened to said low pressure to move said valve member from a primary position to a secondary position; movable auxiliary valve means adapted to open uid communication between said large end and said first exhaust port to permit a first zone of movement of said valve member from said primary position toward said secondary position; means adapted to open iiuid communication between said large end and said second exhaust port to permit a completion of said movement of said valve member from said primary position to said secondary position; and means for returning said valve member to said primary position in the event that said auxiliary valve means closes fluid communication between said large end and said iirst exhaust port during said first zone of movement of said valve member.

24. In a valve device, the combination of: a valve housing having an inlet adapted to be connected to a source of operating fluid under relatively high pressure; a valve member in said housing and of the diierential area type having a small Yend adapted to be subjected to said inlet pressurev and a large end adapted to be alternately subjected to said inlet pressure to move said valve member from a primary position to a secondary position; ilrst port means communieating with said large end and adapted to be opened to iiuid communication with said inlet to admit operating uid to said large end to cause a ilrst zone of movement of said valvemember from said primary position toward said secondary position; second port means adapted to be subsequently opened to uid communication with said inlet to admit operating uid to said large end' to complete said movement of said valve member to said secondary position; -movable auxiliary valve means adapted to open said communication between said rst port means and said inlet; and means for returning said valve member to said primary position in the event that said auxiliary valve means closes fluid communication between said rst port means and said inlet during said rst zone of movement of said valve member. e

CLARENCE J. COBERLY.

-CERTIFICATE oF Col'zcaion, Patent 'ljo 2,511,157. l -'February 16, 1%5.4

-CLARENCE jJ. 'coBERmr -It is hereby certifiedthaterior appear; in the printed specification of the-above numbered' patet 'e'quiztng coixectijon as follows; Page 1|., sek:-

ond column, line 5.6,' for ."iinerlldfead --linerfl'-q page 6, 'eoon column, line 65, for 'ptston'liead --pos'ition---gv page 7, second coluum, 1111140 '26, for "fluid" '.read --flui'z'--g page 11,-second column, line 55, claim 11,

this orreotion therein that the dsangle may conform to-the 'recordof the case 1n t patent-office.

signed me 'sealed this .mauri day of Apr11,-A. D. 19lp5.'

I' Henry Van Arsdale, (SealV Y `ming Gommi'asioner-of Patents.