US2237303A

US2237303A - Pumping mechanism for oil wells

Info

Publication number: US2237303A
Application number: US211181A
Authority: US
Inventors: Ingram X Calhoun
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-06-01
Filing date: 1938-06-01
Publication date: 1941-04-08
Anticipated expiration: 1958-04-08

Description

M 1. x. CALIHUN 23mm PUMPING MECHANISM FOR OIL WELLS.

Filed. June 1, 1938 m 41 Slwets-Sheet l ill/mm ATTORNEY.

TH 1:. x. CAM-HUN asmm PUMPING MECHANISM FOR OIL WELLS Filed June 1, 1.938 4 Sheets-Sheet 2 8M INVENTOR. 6.5, IN GRAN Kim/100w BY 1 i V W ATTORNEY.

PUMPING MECHANISM FOR OIL WELLS Filed June 1, 1938 4 Sheets-Sheet 3 {w NM a! {y p a 1 INVENTOR.

//ve RAM )i. CALHOUN ATTORNEY.

11 9 2. m ALHUN PUMPING MECHANISM FOR OIL WELLS 4 Sheets-Sheet 4.

Filed June 3., 1938 INVENTOR. lNGRAM XML/100m L 1mm? ATTORNEY.

Patented Apr. 8 1941 UNITED STATES PATENT OFFICE PUMPING MECHANISM FOR OIL WELLS Ingram X. Calhoun, Oklahoma City, Okla.

Application June 1, 1938, Serial No. 211,181

15 Claims.

This'invention relates to a pumping mechanism for oilwells, being applicable to wells of various depths including wells having a depth of several thousand feet. In mechanisms for pumping oil from oil wells, great difiiculty has been experienced in breakage of the sucker rods, necessitating' considerable expense and long shut downs. In a well having a depth of about 6,000 feet, the weight of the dead load approximates 14,000 lbs. and that of the live load (column of oil) approximates 10,000 lbs., totalling 24,000 lbs., which, under practical conditions, is lifted about six feet in each power stroke of the power mechanism. As it is usual for the power mechanism to eifect from 10 to 16 pumping strokes per minute, it will be seen that the change in direction of movement of this heavy mass of materials (the sucker rods) subjects them to undue strains, especially at the end of the down stroke and on the start of the up-stroke when the live load is picked up, with the result that the sucker rods or connections between them break and hence necessitate frequent shut downs. Furthermore, additional strains are imparted to the sucker rods during movement thereof in either direction due to obstructions and disalinement in the tubing in which they reciprocate and impurities in the oil. Obviously, where greater output of oil is desired, the number of strokes per minute is increased, the effect of which is to increase the danger of breakage of the sucker rods.

One object of the invention is toprovide an improved load distributing means between the power means and the sucker rods of an oil well her, operable to compensate for variations in the weight of the, load in the lift strokes of the sucker rods and traveling valve in the oil barrel and to relieve strains on the sucker rods during movement thereof in either direction.

Another object of the invention is to provide an improved load distributing mechanism of this "character having a chamber in which an atmosphere is compressed by forcing liquid thereinto and having means for preventing the escape of liquid and for supplying both atmosphere and liquid when required.

Another object of the invention is to provide an improved mechanism of this character having a chamber in which an atmosphere is compressed by the supply of, liquid thereto and in which provision is made to automatically maintain the supply of atmosphere in the compression chamber.

Another object of the invention is to construct an improved load distributing mechanism having an atmosphere compression chamber provided with means for controlling the pressure in the chamber due' to variations in the weight of the load and changes in the exterior atmosphere conditions.

Another object of the invention is to provide an improved mechanism of this character having a chamber in which an atmosphere is compressed by the delivery of liquid thereinto from a liquid chamber and incorporating a liquid reservoir into which escaping liquid flows and provision is made to supply liquid to the liquid chamber from the reservoir to insure an adequate supply thereof in the liquid chamber.

A further object of the invention is to provide an improved load distributing means having a piston operable to compress a fluid and wherein provision is made to automatically control the length of the piston stroke to prevent undue movement of the piston due to variations in the weight of the load.

Other objects of the invention will be apparent to those skilled in the art to which my invention relates from the following description taken in connection with the accompanying drawings, wherein Fig. 1 is an elevation of an oil well and the operating mechanism therefor (the latter being substantially diagrammatic) and having incorporated in it load distributing means embodying my invention.

Fig. 1a is a fragmentary view on the line lala of Fig.1.

Fig. 2 is a fragmentary elevation showing a modified form of construction.

Fig. 3 is a longitudinal section through the load distributing means shown in Fig. l, enlarged.

Fig. 4 is a fragmentary section on the line 4-4 of Fig. 3.

Fig. 5 is a detail sectional view of certain valve mechanisms.

Fig. 6 is a sectional view of a different embodiment of the invention.

Fig. '7 is a longitudinal section through the load distributing means shown in Fig. 2.

Fig. 8 is a fragmentary section similar to Fig. 7,

but showing the parts in operated position.

In the drawings, I indicates the well from which projects the usual tubing 2 having a cap 3 through which the upper section 4 of the sucker rods reciprocates in making the pumping strokes, the tubing 2 having connected to it a discharge pipe 5 which conveys the supplied oil to a suitable reservoir (not shown). The tubing 2 leads into the casing and downward to a point below the oil level and encloses the traveling valve which is connected to the lower end of the sucker rods in the usual way and is operated vertically to effect pumping of the oil up through the tubing 2, this portion of the well and the mechanism therein not being shown, as it may be of any desired construction and forms no part of my invention.

The operating mechanism consists of a motor or driven member (not shown) transmitting power preferably through a belt 6 and pulley 1 to a shaft 8, the latter being suitably mounted in a housing 9. The housing 9- encloses a suitable gear reducing mechanism, operating to drivingly connect the shaft 8 to a shaft l also suitably mounted in the housing. The shaft I0 is provided with a crank l which is connected through a link |2 to one end of a walking beam 13, suitably fulcrumed on a standard or post H. The other end of the walking beam I3 is preferably bifurcated to form a support for the opposite ends of a shaft l4, which forms the pivot for a depending link I (see Fig. 1a). The upper end portion of the sucker rod 4 is operatively connected to the link I5 by a load distributing means indicated as an entirety at I6, whereby the walking beam serves to raise and lower, that is, reciprocate the sucker rods in the'usual manner to effect the pumping operation. The crank II is provided with a counterbalance l1 which is preferably equal to the weight of the dead load plus one-half of the live load, so that the load on the gearing and motor is substantially equal in rocking the walking beam in opposite directions.

Referring particularly to Figs. 1, 3, 4 and 5,

l8 indicates a cross bar through which'extends the'rod 4, the latter being provided with a collar l9 suitably bolted or clamped to the rod and arranged to rest on the cross bar. I8 is connected by bars 20 to an upper cross bar 2|, the bars 20 being preferably threaded at their lower ends in the cross bar l8, and their upper ends extending throughopenings formed in the cross bar 2| and provided with nuts 22 on their upper end to engage the cross bar 2|.

The load distributing means l8 comprises two members indicated as an entirety at 23, 24, relatively movable substantially axially of the sucker rods, one thereof being connected to the cross bar 2| and the other connected to the link l5. In the form of construction now being referred to the member 23 consists of a casing of circular contour connected at its lower end to the adjacent cross bar 2| and having a, transverse wall 25 to divide the casing into an upper chamber 26 in which an atmosphere (preferably air) is compressed and a lower chamber 21 for a body of liquid A (such as light oil). The member 24 consists of a piston 28 which slidably engages the walls of the chamber 21 to force the liquid into the chamber 26, whereby the atmosphere The cross bar therein is compressed, as later set forth, and a piston rod 29 preferably formed integrally with the piston 28 and connected at its upper end to the link l5. The piston rod 29 is provided at its upper end with a bifurcated fitting 29a. in which fits a depending lug on the link I5, a pin 3|] extending through the lug and bifurcations to pivotally connect these parts together. The dividing wall 25 is provided with an integral, upstanding sleeve 3|, through which the piston rod 29 slidably extends, the rod being guided by the inner walls of the sleeve, and the latter is provided at its upper end with an integral annular plate or wall 32, which cooperates with a shell 33 and dividing wall 25 to form the chamber 26, these parts being preferably welded together in liquid and atmosphere tight relation to insure a sealed chamber. The upper end of the sleeve 3| is recessed at 3|a. to provide for a suitable gland. Below the dividing wall 25 and preferably welded thereto is a cylinder 34 with which the periphery of the piston 28 engages, a suitable sealing ring 35 held in position by an annulus 36 being provided to prevent undue leakage past the piston. The lower end of the cylinder 34 is connected (preferably by screw threads) to a bottom wall 31 and surrounding the cylinder 34 and bottom wall 31 is a shell 38, the walls of which are spaced from the cylinder 34 and bottom wall 31 to form a reservoir 39 for liquid (similar to that employed in the chamber 21) into and from which the liquid is conveyed as later set forth. The upper end of the shell 38 is held in engagement with the dividing wall 25 in the manner later set forth. The bottom walls of the closure Wall 31 and shell 38 are formed with alined openings 40, 40a, respectively, in which is mounted the upper portion of a tubular member 4| opening at its upper end into the space within the wall 31 and below the piston 28 for a purpose later set forth. The tubular member 4| is welded to the wall 31, whereas the opening 40a therefor through the shell 38 is sealed by a suitable gland 42 between the tubular member and a collar 38a on the bottom wall of the shell, to insure closing of the reservoir 39. As shown, a ring nut 4|a threaded on the tubular member 4| and tight ened against the collar 38a serves to support the shell 38 in position with its upper end in rigid engagement with the wall- 25. The tubular member 4| extends below the shell 38 and through an opening 43 formed in the adjacent cross bar 2| and carries at its lower end a head 44 which engases the lower side of the cross bar to connect the casing member 23 thereto. By preference,

. the head 44 consists of a plug threaded into the lower end of the tubular member 4| to close it (except as hereinafter pointed out), the tubular member 4| and plug 44 serving as a cylinder for a piston 45 to provide an auxiliary pump for supplying air to the chamber 26 and liquid to the chamber 21, as will later be set forth.

The lower end of the sleeve 3| is recessed at 48 and communicates through a plurality of ports 41 formed in the sleeve with ducts each formed in a plate 48, the outer ends of the ducts forming seats for inlet valves 49 to permit flow of the liquid into the chamber 26 when the wall 25 and piston 28 move one toward the other. In the form of construction shown (Fig. 3), the outer end of each duct leads through the top wall of the plate 48 and the valve element of the valve 49 consists of a plunger 50 slidably mounted in a tube 5| rigidly connected to and depending from the wall 32. The wall 32 is formed with threaded openings to removably receive plugs 52 each of which forms an abutment ior an expansion spring 53, the spring in turn being arranged to engage the upper end of the adjacent plunger 50 and normally tends to force the latter into engagement with its seat. The valves 49 serve to choke the flow of the fluid from the chamber 21 into the chamber 26. bviously, the movement of the plungers may be controlled by an adjustment of the springs; by preference I limit the movement of each plunger by a stop, consisting of a rod 54 which is adjustably threaded through the adjacent plug 52, so that its inner end may serve as an adjustable stop to limit the unseating movement of the adjacent plunger 50. Each rod 54 is sealed by a suitable gland 55. The inner end of the piston rod 29 adjacent the piston is enlarged as shown at We, so as to fit into the recess 46, to shut on the flow of the liquid into the chamber it before the wall 25 and piston 28 reach the end of their movement toward each other. The olfset at the upper end of the enlargement 29a. is of conical shape so as to effect a gradual cut-off oi the liquid as the enlargement approaches the recess. When the flow of liquid through the ports ii is cut-off by the enlargement 29a, at quantity of liquid is confined in the chamber 2i between the piston 2d and wall 25 to act as a dash-pot and hence prevents contact of the piston or parts carried thereby with the wall 25. As shown, the enlargement extends to a point above the annulus it and bolts which secure the latter in place. The outlet for the liquid from the chamber it to the chamber Zll when the wall Zii and piston move away from each other is provided by one or more fittings Ed preferably having a capacity substantially equal to the capacity of the inlet ducts and valves 49. Each fitting tit (only one being shown) consists of a hollow, angular member the vertical portion of which is fixedly mounted in an opening 5i formed in the dividing wall til so as to discharge the liquid into the chamber 2i. The horizontal portion of the fitting 56 is elevated above the wall 25 and its upper and lower walls are formed with aligned openings, the lower opening forming a seat for a choke valve element 58 which projects through the upper opening and slides in a tube 5la rigidly connected to and depending from the wall 32. The Wall 32 is formed with threaded openings to removably receive plugs 52a and between each plug 520. and the adjacent plunger or valve element is an expansion spring 53a normally tending to maintain the valve element in engagement with its seat. The unseating movement of each valve element 58 is limited by a rod 54a the upper portion of which extends through an opening formed in the adjacent plug and has threaded engagement therewith to permit adjustment of the rod endwise, the rod being sealed by a suitable gland 55a.

It will be noted that the valve elements 50 and 5B are shaped at their lower ends so that pressure of the liquid thereon will eifect unseating of the valves. As shown, in Fig. 4, the inlet choke valves and outlet choke valves are arranged alternately around the sleeve 3|, and the movement of each may be regulated independently of the other valves. in the inlet and outlet ducts, flow of the liquid from either chamber to the other is retarded to prevent undue sudden movements between the

members

23, 24.

By preference I provide in the chamber 26 in By providing choke valves close relation to the inlet choke valves 49 a baflie 26a arranged to prevent surging of the oil in streams into and through the body of liquid in this chamber when forced thereinto. The baiiie 2801. consists of a plate extending around the sleeve 3| and formed with a plurality of openings to permit the rise and fall of the liquid therethrough. The plate may fit upon the sleeve 3| and be suitably secured thereto as by welding.

When the operating mechanism is not running, the parts of the load distributing means l6 may occupy the position shown in Fig. 3, the

liquid A filling the chamber 21 and also filling.

the chamber 26 to a level above the inlet and outlet valves 49 and 53, with the atmosphere in the chamber 26 compressed to the desired degree. In the arrangement and construction shown having a piston of 0 inches in diameter and operating in a well having a depth of about 6000 feet, the pressure in the chamber 26 would be approximately 280 lbs. per square inch. In the operation, in the up-stroke or the piston to raise the traveling valve and sucker rods 4, the piston 23 will move relative to the wall 25 and force the liquid through the inlet choke valves 49 into the chamber it to approximately the level indicated by the line a and compressing the atmosphere thereinto approximately 480 lbs. per square inch, thereby relieving sudden strains on the sucker rods. In the down-stroke oi the piston, the built-up pressure in the chamber 2% forces the liquid A through the outlet choke valves 50 into the chamber ti, thereby causing relative movement or the piston iii and wall tit away from each other, so that the weight oi the dead load is distributed during a part oi or throughout the down-stroke. At the end of the down strolre and in starting the up-stroke, the piston til will move relative to the casing lit, and thus force the liquid A into the chamber it and again compress the atmosphere therein, thereby distributing the load on the sucker rods. The forcing of the liquid A into the chamber 26 and therefrom also takes place during the movement or the sucker rods upwardly or downwardly in the event resistance to their travel takes place, so that the load distributing means relieves any and all sudden strains on the rods during their movement. It will thus be noted that in the start of each up-stroke of the sucker rods, the atmosphere in the chamber is put under higher compression and upon release of the applied force or load, the atmosphere expands to force the liquid A back into the chamber 21, the

valves

49 or 58 serving to choke the flow of the liquid in each direction to relieve the rods of sudden strains; also the same operation takes place during movement of the sucker rods in either direction in the event their movement is retarded for any reason. The increase in compression of the atmosphere in each up-stroke of the sucker rods is dependent on the amount of oil taken in by the traveling valve.

Means are provided for automatically supplying liquid A to the chamber 21 and discharging the liquid from the chamber for automatically controlling the level of the liquid in the latter chamber and thus controlling the volumetric capacity of the chamber above the liquid level, the purpose being (a) to maintain a minimum variation in the range of movement of the piston 28 relative to the member 23, notwithstanding changes in the weight of the load (particularly the live load in succeeding up-strokes of the sucker rods) and expansion and contraction of the atmosphere in 3. aeenaoe the chamber 2G due to changes in temperature of the weather, and (b) to insure operation of the load distributing means over a long periodof time without Servicing. These means include the auxiliary pump already referred to. As shown, the piston 65 is provided with an integral rod 58', which is preferably integrally connected to the piston 28, whereby the piston 65 is reciprocated therewith. The piston 35 is formed with a port 69, normally closed by a spring operated ball valve, which in the upstroke of the piston, permits the oil supplied into the cylinder or tubular member 4| due to leakage of liquid past the seal ring 35 or supplied by a pipe 60, as later set forth, to. flow to the lower side of the piston. The rod 58' is formed with a longitudinal opening 6| which leads from the space below the piston 45 as later set forth and is connected at its upper end to a duct 62 leading into the chamber 21 above the piston 28. While the opening GI and duct 62 and the space below the piston 45 are always filled with liquid, at least to a predetermined level therein for a purpose later set forth, the liquid cannot escape past the ball valve for the valve port 59 and in the down stroke of the piston 45 excess oil in the space below the piston will be forced up through an opening 63 formed in the piston, past a ball valve 64a therefore and through the opening 6| and duct 62 into the chamber 21. The ball 64a is normally held seated by the pressure thereon of the liquid in the opening 6| to close the opening 63 in the up-stroke of the piston 45. The reservoir 39 is provided with a supply of liquid A when pumping operations are to start. The supply of liquid A in the reservoir 39 is supplemented at intervals by the operation of a valve mechanism indicated as an entirety at 65, controlled by the relative movement of the

members

23, 24. The liquid A supplied to the reservoir 39 is taken from the chamber 26, such discharge being co-operatively related to the supply of liquid into and through the chamber 21 to control the liquid level in the chamber 26. The valve mechanism 65 is preferably mounted in the reservoir 39 so that its discharge outlet opens thereinto, the upper end of the housing 65' for the valve mechanism terminating in a threaded boss which is screwed into an openingformed in the bottom portion of the wall 3'! to support the mechanism thereon. The inlet port 65a of the valve mechanism is connected to a pipe 66, which in turn is connected to a passage 66a preferably formed in the wall 25 and controlled by an adjustable needle valve 66b to regulate the flow of the liquid to the valve mechanism 65. The inlet port 65a is normally closed by a spring operated ball valve 61 (see Fig. The valve housing 65' is formed with a through opening 68 which communicates with the inlet port 65a and serves as the outlet for the valve mechanism into chamber 39. The upper portion of the opening 68 and the opening through a plug 689: forms a guide for a thrust rod 69 having an enlargement or cam 69a, which, when the rod is moved endwise downwardly, engages with a ball mounted in the inlet 65a in contact with the valve 61 and through the ball 10 operates the valve 61 to permit discharge of the liquid in the pipe 68 into the reservoir. The thrust rod 69 extends upwardly into the path of movement of the piston 28, so that when the relative movement between the wall 25 and piston 28, one away from the other, is sufficient to effect engagement of the piston with the rod 69, the valve 61 will be opened to admit liquid to the reservoir 39. As shown, the plug 69:: is

threaded into the opening 68 to provide a suitable formed by enlarging the lower portion of the opening $6, the rod 69 being normally biased upwardly by a coiled spring interposed between the head ii and a cup-shaped member lib mounted in the lower end of the opening 68. The valve mechanism 65 is operated by the piston 28 when the relative movement between it and the wall 25, one away from the other, is increased, and such operation serves to reduce the quantity of liquid A contained in the chamber 26 to control the liquid level therein. In the event the piston 28 moves away from the wall 25 to approximately its extreme position, the cam 69a will ride past the valve 61 and permit the latter to close so as to prevent an undue quantity of the liquid being discharged from the chamber 26.

92 indicates a nipple mounted in the side wall of the shell 39 above the liquid level therein and arranged to permit the suppl of liquid to the reservoir when necessary. The nipple 92 is preferably closed by a cap 92a. The shell 38 may be provided with a gage (not shown) to indicate the level of the liquid therein or such level in the event it drops to or below a predetermined height.

To prevent the range of movement of the piston 28 and wall, one toward the other, increasing to its extreme limit of movement I provide means, indicated as an entirety at 13, for automatically supplying liquid through the chamber 21 to the chamber 26 to increase its volume therein, that is, raise the liquid level therein in relation to the volume of that portion of the chamber 26 above the liquid level, the effect of which is to reduce the range of relative movement between the piston 28 and wall 25.

The liquid supply means 13 consists in providing on the rod 58 a shoulder 14 which, in the upward movement of the rod 58, engages one end of a lever 15 suitably fulcrumed on the wall 31, and a valve mechanism, indicated as an entirety at 16, arranged to be operated by the lever 75,

to admit liquid tothe pipe 60, which discharges the liquid into the tubular member 4|, whereby the auxiliary pump may force the liquid from the tubular member 4| into the chamber 21, the effect of which is to increase the volume of liquid in the chamber 26. The shoulder 14 preferably comprises a collar slidably mounted on the rod 58' and fixed thereto by a set screw, which permits the collar to be arranged in any adjusted position longitudinally of the rod 58' to effect the operation of the lever 15 at any predetermined position of the rod 58' in the up-stroke of the piston 45, and to thereby regulate the range of relative movement between the

members

23, 24. The valve mechanism 16 comprises a tubular fitting l6 screw threaded at its upper end into an opening formed in the wall 3'! and closed at its lower end by a cap TI and provided intermediate its ends with a valve seat for a valve element 18 (preferably a ball valve), which is normally biased to its seat by a spring 18a. The side wall of the fitting 16' below the valve is formed with an inlet 18b to admit liquid from the reservoir 39 and above the valve with an opening into which the inner end of the pipe is suitably secured. The upper portion of the opening through the fitting 16' forms a. guide for a plunger 19, the upper end of which is disposed in operative relation to the opposite end of the lever 15, so that when said lever is operated, as already set forth,

the plunger 18 unseats the valve element 18 and permits the liquid to flow into the tubular member II.

The liquid delivered from the pipe 88 into the tubular member II will then be forced by the auxiliary pump through the opening 8| and duct 82 into the chamber 21.

The atmosphere is automatically supplied to the chamber 28, the eflfect of which is to gradually increase the range of relative movement of the piston 28 and wall 25, one away from the other, and to then automatically discharge the atmosphere from the chamber 28, the effect of which is to reduce the range of relative movement between the piston 28 and wall 25. The cycle of movement takes place in succeeding movements of the piston to compensate for variations in the load weight and changes in temperature oi the weather.

The atmosphere is supplied to the chamber 28 by operation of the auxiliary pump in the following manner: the head 44 is formed with a through opening 12 shaped to provide a seat tor a ball valve element 12', which is normally closed by the pressure of liquid above it. The lower end of the opening 12 is threaded to receive a plug Ma which is formed with a small opening to limit the intake of air in each up-stroke of the piston 45. In the down-stroke of the piston it, the air which is drawn through the opening it, is iorced up through the opening 63 into the opening 6! where the air will follow along with the liquid forced therethrough or bubble up through the liquid and likewise bubble through the liquid in the chamber 21 and finally pass into the chamber 26. Sufiicient liquid is maintained in the tubular member ll below the piston 45 so that the latter will engage with the liquid in each down stroke of the piston, this liquid being supplied through a very small opening 121) formed in the piston I5, the purpose being to effect pressure on the liquid and air by the piston in its downstroke, whereby the air sucked in through the opening l2 and liquid flowing through the valve it may be forced up through the opening formed in the piston into the opening Bl, As the piston 45 nears the end of its down stroke, a. pin ht, provided on the head 44, operates to substantially close the opening 83, so that the liquid remaining in the bottom portion of the tubular member ill acts as a dash-pot for the piston 45. The supply of atmosphere into the chamber 26 will have the effect of gradually increasing the pressure therein, so that in the succeeding relative movements of the piston 28 and wall 25 one away irorn the other, such movements will progressively increase and ultimately cause the piston it to engage the thrust rod 68 and also operate a valve mechanism, indicated as an entirety at 82, to permit a small quantity of atmosphere to escape in each stroke of the piston 28 to relieve the pressure in the chamber 28 and prevent the piston and casing 23 moving to a position wherein the fitting 29a will engage the wall 32 or a cap 32a thereon. The valve mechanism 82 is preferably associated with the valve mechanism 85. As shown in Fig. 5. the housing 85' is formed with a valved inlet 83 connected to a pipe 83a leading from the upper portion of the chamber 26 and a valved outlet 88 connected to a pipe 84o which extends upwardly through the reservoir 38, its upper end opening thereinto above the level of the liquid A therein, a vent 85 being provided in the shell 38; but obviously the pipe 8M1 may be extended to a point outside the shell.

The housing 65 is formed with a through opening 88 in communication with the outlet port of the inlet 83 and inlet port of the outlet 84, and between these ports the opening 88 is enlarged to form a receiver 88a. A thrust rod 81 extends through the opening 86, being guided in openings formed in plugs 88, 88a, threaded into recesses formed in the upper and lower ends of the opening 88 and providing suitable glands in said recesses. The thrust rod 81 extends upwardly into the path of movement of the piston 28, being normally biased upwardly by the spring operating through rod 69 and bar 1211:. Since the bar 12:1: connects the rods 89 and 81 together, the upward movement of the latter is limited by the head II. The rod 81 is provided with an enlargement or cam 98, which in the normal upper position of the rod is above the outlet port for the inlet 83, so that in the downward movement of the piston 28, the cam 98 will, through a ball mounted in the inlet 83 in engagement with the valve element therefor, open the inlet and permlt atmosphere to flow into the receiver or chamber 860, and in the event the rod 81 is moved downwardly by the piston 28 far enough to effect engagement of the cam 88 with a ball mounted in the outlet 84 in contact with the valve element therefor, the valved outlet will be opened to permit escape of the atmosphere from the receiver 86a, thus reducing the pressure in the chamber 28 to limit the relative movement between the

members

23, 24, one away from the other, so that the fitting 29a. will not engage the cap 82a. Since the receiver 86a is normally closed by the valve for the outlet 84 leading therefrom, the valved inlet 83 may be opened by the cam 98 without danger of the atmosphere escaping and reducing the compression in the cham ber 26.

From the foregoing description it will be seen that in each lip-stroke of the piston 28 air is sucked into the tubular member 4i and then pumped into the chamber 26 and that the resulting increase in pressure therein serves to increase the relative movement between the piston 23 and wall 25 one away from the other and that when this movement increases to an undue extent, the pressure is reduced in the chamber it, as already described, to limit it at approximately a predetermined position.

Due to the fact that I provided for the discharge of liquid from the chamber 28 due to the movement of the piston 28 away from the wall 25, and operation of the valve mechanism 85, as above described, so that the liquid level in the chamber 26 is lowered with each operation of the valve mechanism 65, the volumetric capacity of the chamber above the liquid level is increased, and hence the relative movements of the piston 28 and wall 25, one toward the other, is increased, until the shoulder 14, operates the liquid supply mechanism N. The operation of the mechanism l3 serves to supply the liquid into and through the chamber 21 to the chamber 26, thereby raising the liquid level in the latter and thus reducing the volumetric capacity thereof above the liquid level and re-establishing in the chamber 26 sufiicient atmosphere pressure to limit the movements of the piston 28 and wall 25 one toward the other.

It will thus be seen that the limit of movement of the piston 28 and wall 25 in either direction, one relative to the other, is controlled automatically by the

valve mechanisms

85, 82 and 13 in connection with the auxiliary pump, the desired ,range of relative movement being dependent upon the adjustment of the collar I4. It will also be seen that the range of relative movement of the

members

23, 24, is maintained within substantially predetermined limits, not withstanding the changes in the applied loads and temperature of the weather. It will also be noted that I incorporate in the casing 23 a reservoir for a supply of liquid from which the liquid is automatically drawn to raise the liquid level in the chamber 26, and to receive liquid automatically discharged from said chamber, as required from time to time in the operation of the mechanism.

It will further be noted that the mechanism is self contained and capable of operating over a long period of time without servicing of atmosphere or liquid, or adjustment.

I provide means for throwing out the operation of or disconnecting the

valve mechanisms

65 and 82, when any part of the mechanism is being tested or when, due to the leakage in the traveling valve or other abnormal condition, flow of oil from the well ceases. These means consist in extending the rod 91 through the bottom wall of the shell 38 and providing thereon below the shell a collar 93 adapted to be fixed to the rod in diiierent positions by a thumb screw 94. By moving the rods 69 and 81 downwardly with their cams 69a and 90 below the valves 61 and 84, respectively, and positioning the collar 93 in engagement with the plug 95 which closes the opening through the shell for the rod, these valve mechanisms will be made inoperative, so that atmosphere cannot be supplied to or discharged from the chamber 25 and the liquid level therein will remain substantially constant, and any liquid supplied by the valve mechanism I3 will not afiect the operation of the

members

23, 24, under these conditions.

Fig, 6 illustrates a different embodiment of the invention wherein the construction is somewhat simplified. Referring to this view, 23, 24', indicate the two relatively movable members, the former member comprising a casing I and a compression chamber I00, in which an atmosphere is compressed, having a liquid connection I000, with the casing I00. The bottom wall of the casing I00 is provided with a depending lug I00b fitting into a recess IOI formed in the cross bar 2| and pivotally connected to the side walls of the recess by a pin I02. a cylindrical side wall I03, an upper end wall I04 and a lower end wall I05, the end walls having lateral lugs I06 to which rods I01 are secured to clamp the end walls to the opposite ends of the side wall I03, suitable means being provided to seal the joints between these parts. -The relatively movable member 24' comprises a piston I08 arranged to reciprocate within the casing I00 and a rod I09 for the piston extending through an opening I I0 formed in the end wall I04 and connected to the link I5, preferably in a manner similar to that shown in Fig. 3. The piston I08 is provided with a suitable seal ring III held in position by an annulus H2. The piston I08, wall I03 and end wall I04 form a chamber for the liquid utilized to compress the atmosphere in the chamber I00. The liquid connection I00a consists of a pipe II3 threaded at its inner end into an opening formed in the end wall I04, and connected at its outer end to a fitting H4 and a pipe II leading from the fitting II4 into the lower end of the compression chamber I00, that por tion of the pipe II5 within the chamber preferably being formed with a plurality of ports through which the liquid flows into and out of the chamber. With the piston I08 at substantially The casing I00 consists of the end of its movement away from the wall I04, as shown in Fig. 6, the liquid A fills the cylinder or casing I00 above the piston, the connection I 00a and the lower portion of the chamber I00, and in the relative movement of the members 23', 24', that is, movement of the piston I08 and wall I04 one toward the other, due to a load on the sucker rods, the liquid is forced into the chamber I00 to raise the level therein and thus increase the compression of the contained atmosphere; and upon release of the load the piston I08 and wall I04 move in the opposite direction and the liquid is forced back into the liquid chamber. The

fitting H4 is provided with a valve seat for a valve element 411, which is adjustable by a handle H412 to control or check the flow of the liquid A to and from the chamber I00. The connection I000. preferably serves to rigidly support the chamber I00 on the casing I00.

The end wall I04 is provided on its inner side with an annular boss I04a, which surrounds the rod I09 and co-operates with the inner side wall of the annulus I I 2, in the movement of the piston I08 and wall I04, one toward the other, to form a dash-pot to prevent contact of the piston and boss, The annulus H2 is formed with a circumferential recess II2a. in communication with the liquid chamber and the upper wall of the recess is provided with a plurality of normally closed, spring operated valves IIG (two valves being shown). which release the resulting suction eflfect in the event the boss I040. projects into the space within the annulus II2, as above set forth, upon movement of the piston and wall one away from the other.

The piston rod I09 extends downwardly below the piston I08 and is provided at its lower end with a piston III reciprocatable in a cylinder II8, the latter being closed at its lower end by an end plate I23a, to provide an auxiliary pump. The lower end of the piston rod I09 is formed with an inwardly extending opening 8' and a duct H9, in connected relation, the latter communicating with the liquid chamber above the piston I08. The piston II! has bolted on its lower side a plate I which secures a suitable seal ring I2I in position. The plate I 20 is formed with an opening I22 forming a seat for a valve element I22 which is normally biased to its seat by a spring I22a, but is unseated in the downward movement of the piston by an up-standing pin I23 provided on the plate I230, whereby liquid in the cylinder II8 below the piston is pumped through the opening H8 and duct I I9 into the liquid chamber. The pin I23, after unseating the valve I22 to permit a quantity of liquid to flow through the adjacent opening, serves to close the opening to prevent further flow of the liquid therethrough, so that the remaining liquid in the cylinder II8 may serve as a dash-pot. For this purpose a predetermined quantity of liquid having a level above the end of movement of the piston in making its shortest stroke relative to the wall I05 is maintained in the cylinder. Oil is supplied to the cylinder II8 below the piston II'I through a relatively small opening I24 formed in the plate I20, also by leakage past the seal ring III and seal ring I2I, and/or supplied through a fitting I25, mounted in an opening I25 formed in lower end wall I05, the opening being closed by a removable screw plug I26. The liquid leaking past the seal ring III and/or supplied through the fitting I25, gravitates to the well I21 formed in the end wall I; the liquid in the well is sucked into the cylinder H8 through a plurality of valves I28 (two valves only being shown) formed in the Dlate I23a.

The plate I 23a is interposed between the end wall I05 and the adjacent end 01 the cylinder IIB, and the latter is provided with lugs Ill, engaged by bolts I29 screwed intothe end wall I05 and operating to rigidly clamp these parts together, the joint between the plate Illa-and cylinder II8 being liquid andair-tight. when it is found desirable to increase the volume of air or atmosphere in the compression chamber I00, the plug I2Ii is removed to permit the air to flow into the casing I00, which is under partial vacuum due to the operation of the auxiliary pump. Such supplied air is drawn in through the valves I20 and then pumped through the opening I22, into the opening Ill, so that it may bubble up through the body of liquid into the chamber I00. The pump will continue to supply air to the chamber I00 until the required pressure therein is built up, following which the plug I26 is replaced. If the air becomes incorporated in the liquid in the cylinder III, it will be carried along with those portions of the liquid pumped therefrom. 4

If it is found necessary to increase the amount of liquid in the chamber I00 at any time, the

plug 11126 is removed and the liquid introduced through the fitting I25 and this oil will gravitate into the Well i2! from which it will be pumped through the opening II! duct H9, and liquid chamber into the chamber Ill. The liquid level in the chamber I00 may be lowered by opening the valve I30, and air pressure therein may be reduced by opening a valve Ill connected to a pipe I32 in communication with the upper portion of the chamber.

Figs. 2 and 7 illustrate another embodiment oi the invention which is adapted to be interposed between the uppermost section of the connection between thev rods and the walking beam ll. In this form of construction the relatively movable members consist of an inverted cylinder, indicated as an entirety at 200 with its end wall in engagement with a collar 20! becured to the upper portion of the rod I by bolts fill and a piston, indicated as an entirety at till, supported on the side wall of a cup-shaped member 204, the bottom wall of which rests on the cross bar it. By preference, the cylinder 20W, piston 2'03 and member 204 surround the suclrer rod 4, the cylinder being provided with an axially disposed sleeve 205 fitting the rod l and extending downwardly from its end wall and preferably formed integral therewith; The lower end of the sleeve is provided with screw threads to support a collar 205a, whereby the collar may be adjusted endwise of the sleeve. The purpose of the collar will be later set forth. The piston is formed of related sectionswhm'eby the chambers, recesses, openings or ducts hereinafter referred to may be provided for when the sections are assembled and positioned in the cylinder. gagement with the outer wall of the sleeve 205 and inner wall of the cylinder side wall. the walls of the piston having annular recesses 205 for seal rings 201. The space within the cylinder 200 is filled with a quantity of liquid A (such as light oil) to form an atmosphere or air seal between the piston and the cylinder and the remaining space is filled with atmosphere under any desired pressure. The piston 202 is Gil The piston 203 has sl ding enformed in its side wall with an inlet 208 having a vertical section communicating with an enlarged recess 200 to accommodate a ball valve. Theball normally engages the outlet port of the inlet 208 to serve as a valve element to close the inlet. The recess 209 communicates with the inlet end of a duct 2I0 the outlet end of which communicates with a chamber 2. The upper end of the chamber 2 is closed by a screw plug 2I2 having a valved controlled opening 2|! through it opening into the cylinder. 2| I indicates a piston mounted in the chamber 2 and provided with a rod 2l5, which extends downwardly through the piston 203 and is connected at its lower end to the collar 200a. The collar 205a is provided with an annular shoulder 2001) on which the rod rests and an annular rib So which projects into a recess formed in the rod so as to connect the collar and rod together, whereby relative movement between the cylinder 2" and piston 203 will efiect a like movement of the piston 2 relative to the walls of the chamber 2I I. The upper end of the piston 2I0 is formed with a recess M6 and an opening leading therefrom downwardly through the rod and laterally of the latter to communicate with the chamber 2| I. i l valve 2H0: normally closes the opening leading into the recess 2I8. Since the piston 2N reciprocates in the chamber 2, it will be seen that it operates as a pump to suck air in through the inlet 208 and duct 2I0 and to force it to the upper side of the piston and in turn to pump it through the valved opening 213 into the cylinder 200. The recess H6 and space above the piston M0 is partially filled "with liquid supplied through an opening 2W. the size of which permits liquid to drip into this space to maintain a small quantity of the liquid therein at all times. In the down stroke of the piston 2, a partial vacuum is formed above the liquid in the recess 2H6 and air flows through the piston into this recess past the valve 2M: and rises into the space above the liquid. In the tip-stroke of the piston 2 ll, this air together with excess liquid in the recess W6, is forced through the openinn lid into the cylinder 200 It will be noted that the annular recesses 208 communicate through ducts 220 wi the chamber 2H so that liquid leaking irom the recesses and accumu ating in the chamber 2M will be pumped by the piston 2 through the opening 2I3 into the cylinder 200. The rod 2! 5 is sealed by a suitable gland 22 l.

222 indicates an opening extending through the piston 203, the intermediate portion thereoibeing enlarged at 223 to form a receiver or chamber and the upper end of the lower smaller portion of the opening forming a seat for a valve 224 to close the opening. 225 indicates a tube which slides n the upper smaller portion of the opening 222 and an opening formed in a hollow plug 2 6 screwed into the upper end of the opening 222. which is enlar ed to accommodate a suitable gland to seal the tube 225. The tube 225 is closed at its op os te ends. but adlacent to its ends it is formed w th lateral ports communicating "with the nt ri r of the tube. the port at the upper end of the. tube permitting the atmosphere in the cylinder to flow into the tube. The tube 225 is normally biased upwardly by a spring 221, within the receiver 223. acting through a device 2230 (preterablv a ball) in engagement with the lower end of the tube 225, so as to dispose the upper end of the tube in position to be engaged by the end wall of the cylinder 200 and moved endwisc.

When the tube 225 is biased to its uppermost postion (see Fig. 7), the port in the lower end portion thereof is above the upper end wall of the chamber 223 and closed by the adjacent walls of the opening 222, but upon relative movement of the cylinder and piston far enough in the direction to eifect engagement with and operation of the tube 225, the atmosphere in the cylinder will flow through the tube and be admitted to the chamber 223 (see Fig. 8) and in the movement of these parts in the opposite direction to the position shown in Fig. 7, a thrust pin 228 mounted on the shoulder and loosely fitting the lower portion of the opening 222 will unseat the valve 224 and permit the escape of the atmosphere from the chamber 223, sufllcient clearance between the pin 228 and walls of the opening being provided for this purpose. By preference, the spring 221 which normally tends to move the tube 225 upwardly is utilized to normally maintain the valve 224 in engagement with its seat.

Fig. 7 shows this form of construction when the parts are at rest, but in operation atmosphere is constantly being pumped into the cylinder 20!! by the piston 2, as already set forth, so that unless the pressure therein is relieved, the collar 205a would engage the piston 203. To prevent this engagement I provide the tube 225 and dispose its upper end in the path of movement of the cylinder end wall, so that the latter will operate the tube and permit it to discharge atmosphere into the receiver 223,.and I provide between the receiver and a portion of the cylinder (that is, the collar 205a thereon) an escape means, so that in the movement of the collar toward the piston the atmosphere is allowed to escape and thus reduce the pressure in the cylinder. Accordingly, the pressure in the cylinder is automatically controlled.

The ball 223a yieldingly seats against the lower end of the adjacent portion of the opening 222 to close it, when the tube 225 is biased to its uppermost position.

To those skilled in the art to which my invention relates many changes in construction and widely diifering embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. My disclosures and the description herein are purely illustrative and not intended to be in any sense limiting.

What I claim is:

1. In a well pumping mechanism, the combination with 'power means and sucker rods arranged to reciprocate in the well, of load distrlbuting means forming the operating connections btween said power means and said sucker rods for reciprocating the latter, said load distributing means comprising relatively movable members connected to said power means and sucker rods, respectively, one of said members includ ing a closed space for atmosphere under pressure and the other member being mounted to move within said first mentioned member, whereby the atmosphere is compressed in the relative movement of said members in one direction and expanded in their relative movement in the opposite direction, and means automatically actuated by said members due to excessive relative movement thereof in one direction for discharging atmosphere from said closed space.

2. In mechanism for well operations, the combination with power mechanism and sucker rods, of a pair of relatively movable members eonnected to said power mechanism and said sucker rods, respectively, one of said members comprising a piston and the other member comprising a casing forming a closed chamber for a fluid in a gaseous state under pressure and walls which cooperate with said piston to form a chamber filled with fluid in a liquid-state, and connections between said chambers, the relative movement of said members due to an increased load on said sucker rods or inertia serving to force liquid from said liquid chamber into said compression chamber to compress the atmosphere therein, and means automatically opera-ted by the relative movement of said members for varying the volume of liquid in said chambers.

3. In mechanism for well operations, the combination with power mechanism and sucker rods, of a pair of relatively movable members connected to said power mechanism and said sucker rods, respectively, one of said members comprising a piston and the other member comprising a casing forming a closed chamber for an atmosphere under pressure and walls which cooperate with said piston to form a separate chamber connected to said compression chamber, said separate chamber and a portion of the compression chamber being filled with liquid, the relative movement of said members due to an increased load on said sucker rods or inertia serving to raise the level of the liquid in said compression chamber and compress the atmosphere therein, and means for con-trolling the level of the liquid in said compression chamber to compensate for variations in the weight of the load or changes in temperature.

4. In mechanism for well operations as claimed in claim 3 wherein said controlling means comprlses a reservoir, means for discharging the liquid from said compression chamber into said reservoir, and separate means for pumping liquid from said reservoir into said separate chamber.

5. In mechanism for well operations, the combination with power mechanism and sucker rods, of a pair of relatively movable members connected to said power mechanism and said sucker rods, respectively, one of said members comprising a piston and the other member comprising a casing forming a chamber for an atmosphere under pressure and Walls which cooperate with said piston to form a separate chamber connected to said compression chamber, said separate chamber and a portion of the compression chamber being filled with liquid, the relative movement of said members due to an increased load on said sucker rods or inertia serving to raise the level of the liquid in said compression chamber and compress the atmosphere therein, means actuated by each relative movement between said members for supplying air .to said compression chamber and simultaneously discharging liquid therefrom to lower the level of the liquid therein, means permitting the escape of :air from said compression chamber to limit the travel of one member relative to the other in one direction, and means for supplying liquid into said compression chamber to limit the travel of said member relative to the other memher in the opposite direction.

6. In a mechanism for well operations, the combination with power means and sucker rods reciprocatable in the well, of operating connections between said power means and said sucker rods comprising a cylinder and a piston therein, said cylinder being charged with air under pressure, means operated by the relative movements between said cylinder and piston for supplying air into said cylinder and means operated by a predetermined relative movement between said cylinder and piston permitting the escape of air from said cylinder.

7. In mechanism for well operations, the combination with power means and sucker rods reciprocable in the well, of operating connections between said power means and said sucker rods for operating the latter and comprising relatively movable members connected to said power means and sucker rods, respectively, one of said members consisting of a cylinder and the other member consisting of a piston in said cylinder arranged to form a closed space therein partially filled with iiquid, the space above the liquid being filled with air under pressure, an auxiliary pump, means for supplying to said pump liquid escaping past said piston, and an air inlet connected to said pump, said pump being carried by one of said members and arranged to be operated by the other member, whereby said auxiliary pump is operable [to force the air and iiquid into said cylinder above said ston.

8. In mechanism for well operations, the combination with power means, a frame connected to said power means and provided with a cross bar formed with an opening and sucker rods adapted to reciprocate in a well, the upper portion of said rods slidably extending through the opening in said cross bar, of an inverted cylinder and a piston therein forming between them a closed chamber filled with atmosphere under pressure, means for securing said cylinder to said sucker rods, said means including an axially disposed tubular memher into which said sucker rods extend and said piston surrounding said tubular member and mounted on said cross bar.

9. In mechanism for well operations, the combination with power means, a frame connected to said power means and provided with a cross bar, which is formed with a vertical opening, and sucker rods adapted to reciprocate in a well, the upper portion of said rods extending through and reciprocatable in said opening and provided with an abutment, of a cylinder and a piston therein formed with axially disposed openings through which the sucker rods extend and interposed between and engaging with said cross bar and said abutment, said cylinder and piston forming between them a closed chamber filled with air under reciprocatable in said opening and provided with an abutment, of an inverted cylinder engaging said abutment and a piston in said cylinder and engaging said cross bar, said cylinder and piston forming between them a closed chamber filled with air under pressure, said cylinder being provided with an axially disposed tubular member through which said sucker rods extend and said piston surrounding and sl-idably fl tting said memher.

11. In mechanism for well operations, the combination with power means, a frame connected to said power means and provided with a cross bar formed with an opening and sucker rods adapted to reciprocate in a well, the upper portion of said rods slidably extending through the opening in said cross bar, of an inverted cylinder and a piston therein forming between them a closed chamher filled in its lower portion with liquid and above the liquid with atmosphere under pressure, means for securing said cylinder to said sucker rods, said means including an axially disposed tubular member into which said sucker rods extend and said piston surrounding said tubular member and mounted on said cross bar.

12. In a well pumping mechanism, the combination with power means and sucker rods arranged to reciprocate in the well, of load distributing means forming th operating connections between said power means and said sucker rods for reciprocating the latter, said load distributing means comprising relatively movable members connected to said power means and sucker rods, respectively, one of said members comprising a cylinder and the other member comprising a piston forming with the cylinder a chamber for a body of liquid, the upper end of the cylinder being closed and forming a space above the liquid for atmopshere under pressure, whereby the atmosphere is compressed in the relative movement of said members in one direction and expanded in their relative movement in the opposite direction, and means actuated by the relative movement of said members for injecting iiquid escaping past said piston into said chamber.

:13. In a well pumping mechanism, the combination with power means and sucker rods arranged to reciprocat in the well, of load distributing means forming the operating connections between said power means and said sucker rods for reciprocating the latter, said load disitributing means comprising relatively movable members connected to said power means and sucker rods, respectively, one of said members comprising a cylinder and the other member comprising a piston forming with the cylinder a chamber for a body of liquid, the upper end of the cylinder being closed and forming a space above the liquid for atmosphere under pressure, whereby the atmosphere is compressed in the relative movement of said members in one direction and expanded in their relative movement in the opposite direction, and means operated by the relative movement of said members for increasing or decreasing the compression in said closed chamber.- 1

14. In a well pumping mechanism, the combination with power means and sucker rods arranged to reciprocate in the well, of load distributing means forming the operating connections between said power means and said sucker rods for reciprocating the latter, said load distributing means comprising relatively movable members connected to said power means and sucker rods, respectively, one of said members comprising a cylinder and the other member comprising a piston .forming with the cylinder a chember for a body of liquid, the upper end of the cylinder being closed and forming a space above the liquid for atmosphere under pressure, where. by the atmosphere is compressed in the relative movement of said members in one direction and expanded in their relative movement in the opposite direction, means actuated by said members due to excessive relative movement thereof in one direction to reduce the compression in said compression chamber and separate means actuated by said members due to the relative movement thereof for supplying air into said chamber.

15. In a well pumping mechanism, the combination with power means and sucker rods arranged to reciprocate in the well, or load distributing means forming'the operating connections between said power means and said sucker rods for reciprocating the latter, said load distributing means comprising relatively movable members connected to said power means and sticker rods, respectively, one of said members comprising a cylinder and the other member comprising a piston forming with the cylinder a chamber for a body oi. liquid, the upper end of the cylinder being closed and forming a space 10 above the liquid for atmosphere under pressure, whereby the atmosphere is compressed in the relative movement of said members in one direction and expanded in their relative movement in the opposite direction, air intake means for supplying atmosphere into said cylinder, and means operated by a predetermined relative movement 01' said members in one direction for discharging atmosphere from said cylinder.

INGRAM X. CALHOUN.