US2351398A

US2351398A - Hydrovacuumatic balance

Info

Publication number: US2351398A
Application number: US424761A
Authority: US
Inventors: Conrad R Buchet
Original assignee: DARRELL MARSDEN DOWDING; JOHN CUMMINGS TYLER
Current assignee: DARRELL MARSDEN DOWDING; JOHN CUMMINGS TYLER
Priority date: 1941-12-29
Filing date: 1941-12-29
Publication date: 1944-06-13
Anticipated expiration: 1961-06-13

Description

June 13, 1944. c. R. BUCHET v HYDROVACUUMATIC BALANCE 6 Sheets-Sheet 1 Filed Dec. 29, 1941 IN VENTOR C. R. Buc/Ief; BY k 'ATTORA/Ey June 13, 1944. I c, ug- ET 2,351,398

' HYDROVAGUUMAIIC BALANCE Filed Dec. 29, 1941 e SheetS -Shee t 2 Pig- E 1N VENTOR.

C. R. Buchet BY Won/ v A TTORNEY June 13, 1944. I Q R C T HYDROVACUUMATIC BALANCE Filed Dec. 29, 1941 6 Sheets-Sheet 5 Fig 5 7.x was! 0 I 1 INVENTOR.

June 13, 1944. I c. R. BUCHET HYDROVAGUUMAT I C BALANCE e Sheets-Sheet .4

Filed Dec. 29, 1941 INVENTOR. BY C. R. Bus/wet AT TOR/YE June 13, 1944. c. R. BUCHET HYDROVACUUMATIC BALANCE 6 Sheets-Sheet 5 Filed Dec. 29, 1941 mvawron C. R. Buche't June 13, 1944. c, uc 2,351,398

I HYDROVA'CUUMATIG BALANCE 'Filed Dec. 29, 1941 6 Sheets-Sheet 6 lFi lU INVENTOR. .6. R. Bucket Patented June 13, 1944 HYDROVAGUUMATIC BALANCE I Conrad R. Buchct, Los Angeles, Calif., assignor of one-third to Darrell Marsden Dowding and one-third to John Cummings Tyler, both of Los Angeles, Calif.

Application December 29, 1941, Serial No. 424,761

4 Claims.

This invention relates to hyd rovacuumatic balances.

The general object of the invention is to providea novel balance or lifting member which is particularly adapted for use in pumping wells such asoil wells,

A more specific object of the invention is to provide a novel cylinder apparatus which is particularly adapted for reciprocating the walking beam of a pump jack.

Another object of the invention is to provide a well pumping apparatus wherein a walking beam supported by a hollow Samson post is employed and wherein the beam is reciprocated by a piston and cylinder construction which is actuated by fluid which passes to and from the interior of the Samson post during the pumping operation.

Another object of the invention is to provide a novel Samson post for an oil well pumping l apparatus.

' Another object of the invention is to provide 'a' cylinder construction for operating a walking beam, wherein the cylinder is actuated by different fluids under pressure.

A further object of the invention is to provide a cylinder construction for operating a pump jack walking beam and wherein the device may be operated by liquid under pressure, and/ or com- "pressed air and/or by a partial vacuum, all acting simultaneously.

A further object of the invention is to pro- 'vide' a pump jack including an operating mem- I ber operable by liquid under pressure and wherein a continuously moving pump is employed to move the fluid to and from the operating mem- 'ber Another object of the invention is to provide a pump jack including a liquid operated cylinder and piston device, whereby liquid is pumped to and from the device and wherein the movement Another object of the invention is to provide a novel valve control; for operating a hydraulic actuated cylinder member.

Other objects and advantages of my invention 1 is a side elev'ation partly in section showing a well pumping apparatus embodying the 3 features of my invention;

' Fig. '2 is a side elevation partly in section on an enlarged scale showing the sucker rod operating end of theapparatus;

of the liquid serves to compress a fluid which aidsin thepumping operation.

Fig. 3 is a section taken on line 3-30: Fig. 2; Fig. 4 is a section taken on line 4-4, Fig. 2; Fig. 5 is a view similar to' Fig. 3 showing the operating end of the apparatus;

, acters, I have shown my invention as embodied in an oil well pumping device which is indicated generally at H). As shown, the device includes a supporting Samson post II which pivotally supports a walking beam l2 on a pivot l3. The walking beam includes a saddle M which supports a cable l5 which is adapted to be connected to the polish rod of an oil well pump.

At the end of the walking beam, which is remote from the saddle I4, I provide a nut member l6 which is slidably'mou'n'ted on ways I! on the walking beam and is movable by means of a hand wheel I8 operating a screw H! which enages the nut member l6.

Beneath the member I 6, I arrange a large cylinder 20. The entire apparatus is shown as V mounted on a base 2| which supports an engine,

such as an internal combustion engine, 22. The intake manifold of the engine 22 between the carburetor andthe enginev communicates through a conduit 23 with the lower portion of the cy inder 20 while the exhaust from the, engine 22 communicates through a conduit 24 with the upper portion of the cylinder.

The conduit 24 includes a cooling fin 25 and a check valve 26 which permits passage of ex- 'of the present invention, since valves of the character mentioned are'old and well known.

, The construction-is such that when the engine 22 is operating a partial vacuum is produced in the lower portion of the cylinder and at the same time heated products of combustion under pressure are introduced into the upper portion of the cylinder 20 through the conduit I4. If the pressure in the upper portion of the cylinder becomes excessive, it is relieved through the valve In order that the cylinder 29 may pivot during its slight forward and backward movement, the cylinder is provided with a lower closure 23 which engages a flange 29 on the cylinder and is held in place by bolts 30 (see Fig. 6). The closure 28 includes a plate 3| having a pairjof depending ears 32, which are apertured as at 33. The base 2| includes stirrup members 34 which include spaced arms 35 receiving the cars 32. The arms 35 include apertures 36 and in the apertures 33 and 33 I arrange pins 31 which serve to pivotally support the cylinder 20.

To accommodat movement of the cylinder 23,

the conduit 23 includes a flexible portion 38 which communicates with an inlet nozzle 39 to the cylinder 29.

Mounted within the cylinder '25, I show a piston construction which is indicated generally at 40. As shown, the construction includes a piston head portion 4| and a tubular piston rod portion 42 welded thereto as at 43. The upper end of the tubular portion 42 is provided with a closure 44 which is held in place as by bolts 45. The closure 44 includes ears 46 which receive an arm 41 shown as integral with the sliding nut Ni. A pin 48 pivotally connects the

members

46 and 47. i

The piston head 4| is provided with a face portion 59 which engages a peripheral packing 5| so that a-tight joint is provided. The piston includes a hole 52 which is shown as closed by a one way ball Valve 53which is provided with an apertured guard cap 54.

In operation, when the piston 49 moves to a location 'adjacentto the lower-end of the cylinder 29, surplus liquid in the lower portion of the cylinder will pass through the hole 52 into the upper portion of the cylinder.

In order to prevent liquid in the lower portion of the cylinder from entering the nozzle 39, the latter is shown as extended upwardly into the cylinder and thus its upper end is above the level of any liquid which might be in the lower end of the cylinder. A recess 55 in the lower end of the piston receives 'theprojecting portion of the conduit nozzle 39. A .ga'sket .56which may be made of soft material and arranged in the recess 55 closes the end of thenozzle when the piston is in the fully lowered position. This prevents liquid from splashing into the nozzle end.

Th base 21 is 'apertur'ed at 51 '(Fig. 6) to receive a hollow column '5'8which'extends into the cylinder'zll. 'In order'to support this column fixed with respect to the cylinder 20, the column is provided with a'collar 59 which engages a gasket 69. A nut 6| threaded onto the column 58 serves to hold the parts assembled.

The column 58 is spacedfromthe tubular member 42 and passes through 'an aperture 62 in the piston head portions 4| "and 50. A packing gland 63 on the piston serves to provide 'a tight joint. The upper end of the hollow column 58 has a closure 64 thereon on which a piston head 65 is secured as by bolts 66. A packing member 6'! is provided on the piston head '65 and slidably engages the interior of thetubularmember 42.

i As shown, theengine 22 drives a V-belt pulley 69 which through the belt '10 drives a pulley 1| on a pump T2. This pump '12 "has its inlet connected to a conduit 13, while its outlet is connected to a conduit 14.

The conduits 13 and 14 are connected to a four-way valve 15. The valve includes a valve member 15 adapted to be rocked by a rod 11 to be presently described. The valve 15 includes four ports one of which communicates with the conduit 13 and another of which communicates with the conduit 14, the third port communicates and beneath the partition includes a pipe 82 which communicates with a pipe 83 the latter communicating with the interior of the Samson post above the partition 8|. The pipe 82 includes a check valve 84 which permits upward flow of fluid but prevents downward flow. The Samson post just below the partition 8| contains a check valve 85 which permits flow of air into the'Samson post but prevents flow therefrom. Above the partition 8|, the Samson post includes a pressure operated safety valve -86 which relieves excessive pressure within the Samson post.

The pipe 83 communicatesw'ith a flexibletube 91 which in turn communicates with 'a pipe '88 which communicates with the upper portion of the cylinder 20. The pipe 88 includes an overload, safety valve 89 which opens under excessive pressure in the pipe "88.

The pipe 83 includes a valve 90 which includes a valve stem 9| which extends upwardly. The valve stem 9| is normally urged to 'valve closing position by a spring 92. The valve stem passes through a slot 93 in the walking beam |'2 and the valve is adapted to be moved from its seat by a nut 94 threaded onto the stem 9|. The stem 9| and nut 94 pass through ahole 95 in the walking beam. The construction is such that the valve '90 is normally closed.

When the walking beam l2 approaches .itsextreme upper position, the walking beam engages the nut 94 andlifts the valve stem '9 thus .opening theva'lve 99 and allowing passage .fromthe upper portion of the Samson post through "the

pipes

83, 81 and 88 to the cylinder 29 .so that fluid under pressure in the upper portion of the .Samson post will pass to the space betweenlthe tubular member 42 and the cylinder '20 and willact upon the portion of the piston 40 Which is exposed in the space mentioned andthus will urge the piston downwardly.

The system including the lower portion .of the Samson post, the pipes'13,.'14,"|3 and 19,.the valve l5, pump 12,, hollow 'colmn 58-and=space 95 between the hollow column .58 and the tubularzfmember 42 contain a liquid such as .oil. .A hole 95' affords communication toathe-space 95 andthe relation'of the variousparts and the amount'ofoil in the system is such lthat when the pump 12 operates and the rod TI .is actuated up and down, oil will be pumped'from-the Samson post to the space 95 and vice versa. 'When the oil .is pumped into the space 95 it acts upon .the portion .of'the piston 4| which is aligned with thelspace 95, thus forcing the piston downwardly. .-As the piston moves downwardly, it moves thetu'bular member 42 downwardly thus rocking the walking "beam and pulling the cablenpwardly.

The rod 11 extends upwardly and across the walking beam I2 and the upper end is threaded as at 96 and 96and receives an upper nut 91 and a lower nut 98 thereon. The nuts 91 and 98 are .spaced apart and the portion between the threads .98 and 96'; passes through aligned slots 98' in the walking'beam. As a result of the construction, when the connecting beam approaches the maximum lift of the cableIS, the walking beam will engage. the nut- 98 and push the rod 11 down- .wardly thus, reversing I the direction of flow through thevalve I6. I

When the walking beam approaches the position of maximum lowering of the cable I5, the walking beam will engage the nut 91 and thereby reverse the direction of flow through the valve Asa result of this construction, the liquid in .the' lower portion of the Samson post will be forced to and from the space 95 as described.

The amount of liquid which is preferably oil,

in the system will be such that when the pump is operating to transfer liquid to the Samson post, and the liquid is rising in the Samson post, the maximum height of liquid will preferably be just below the location where the conduit 82 enters the Samson post just below the partition 8|.

As the liquid rises in the Samson post, the valve 99 being closed, the air above the liquid in .the Samson post is compressed and is not released until the valve 90 is opened by the engagement of the nut 94 with the walking beam at which time the air which has been compressed .in the Samson post passes from the valve 90 through the tube 81 and pipe 88 and into the cylinder 20 where it reacts downwardly against the exposed portion of the piston 42. At the same time liquid is being forced into the space 95 and is also engaging a portion of the piston 42 to move the latter downwardly and thereby the sucker rod and the oil in the well are raised.

The lower face of the piston 40 in the cylinder 20 while this is occurring is subject to the partial vacuum in the cylinder which partial vacuum has been produced partially by the movement of the piston in the cylinder and partially by the action of vthe' engine, 22 in withdrawing air through the conduit 23. The action of the compressed air not only increases the efiiciency of the apparatus, but it also tends to cushion the effect caused by the pumping'of the oil from the container to the cylinder and vice versa. This oil is under considerable pressure and as it is not compressible, there is an interval when the valve member I6 changes its position from one direction to another during which more or less strain is thrown upon the operating parts and with the air cushion, not only is this strain somewhat relieved, but some lifting effect is produced from the compressed air which has reduced the strain.

In order that the amount of compressed air' available to pass into the cylinder 20 may be increased I show an air compressor 99 which is driven by a V-belt I from a pulley II shown as mounted on the shaft IUI of the pump I2. The air compressor has its inlet conduit I 02 communioating' with the lower portion of the cylinder 29; The conduit I02 includes a one way valve J03 which opens when thepartial vacuum in the lower portion of the cylinder increases above a desired amount and allows the compressor to draw air directly from the atmosphere. The outlet I94 from the compressor communicates with a valve I which valve permits flow to a pipe IIII5 which leadsto the pipe 82 on the Samson post below-the partition 8| or with a pipe I01 which discharges into a compressed air receiver I08. The valve includes an operating portion I09 which is operated by a pin III] on an arm 11 which is arranged on the rod 11 previously described. The construction issuch that as the liquid level in the Samson post is beingv lowered, the valve I05 will direct compressed air from the pipe I04 through the pipe I06 in the Samson post and will react upon the liquid therein tending to thereby force the liquid from the Samson post. I i

Whenthe, valve I6 is reversed by the rod 11 and the liquid is caused to rise in the Samson post, the valve I95 will also be reversed and will cut off the pipe I04 from the pipe IBSand place it in communication with the receiver I 08 so that air pressure is stored in the receiver I08.

Thereceiver I08 has anoutlet I II which communicates through a valve H2 with the pipe I I3 which extends to the pipe 83. The valve H2 includes an operating portion II 4 which is connected to the lower portion II5 of the stem 9| of the valve 99 so that when the valve 99 is operated, the valve I I2 will also be operated. A suitable packing gland II5 on the valve prevents leakage about the stem H5.

The construction is such that when the valve 93 releases the air :compressed in the upper portion of the Samson post, the valve II2 will re lease the air in the tank 598 and this air will pass through the pipe II3 into the pipe 83 where it will be free to enter the cylinder 20 to thus aid in pushing down the piston. The pipe I 04 includes a safety valve III which opens to the atmosphere whenpressure in the pipe I04 becomes excessive. I

Above the piston head 4!! and between the outer cylinder 29 and the tubular piston 42, a liquid such as oil is provided to serve as a lubricant and also as a seal. The upper level of this liquid is indicated at 42*. In the Samson post liquid such as oil, is maintained above the partition 81. The upper surface of this liquid is indicated at 42 A drain valve 42 is provided in the Samson post above the partition 8i.

In the operation of the device, when the motor 22 is operated the intake to the motor causes a partial vacuum to be produced in the lower end of the cylinder 29 while the products of combustion from the motor pass to the upper portion of the cylinder. Thus the piston 40 is urged downwardly in the cylinder 20. At the same time, the pump I2 is operated and liquid is pumped back and forth'between the space 95 (between the column 58 and the tubular member 42) and the lower portion of the Samson post. This liquid acts upon the top of the inner portion of thepiston head 4| and urges the same downwardly.

The liquid in the Samson post compresses air below the partition 8| and this compressed air finds its Way to the upper portion of the cylinder 20'. Air is also compressed .by the compressor '99 and this compressed air (when the liquid level is falling in the Samson post) enters the Samson post and thus increases the action of the pump I2. At another time the compressed air of the compressor 99 enters the container I 08 to be released therefrom so that it may act upon the upper surface of the piston 4| as previously described.

In Figs. 7, s and 9 inclusive, I Show a modification of m invention which is indicated'general W at I50. In this modification, the walking beam 4-51 is provided'a't one-end with a saddle I52 inder I61.

engaging a cable I53 which is adapted to be connected to the polish rod of the well pump. At its other beam, the walking beam is provided with a saddle I54 over which a cable I55 extends. This cable I55 is connected by a turnbuckle I56 to a cable I51 which is anchored in an eye member I58 secured to the base I59 of the apparatus.

The cable I55 is substantially vertical. j

The walking beam I-I includesa bracket I60 which is connected to an ear I60 on a closure member I6I by a pin I62. The closure member I6I includes a flange I63 connected to a flange I64 of a tubular member I65 as by bolt I66.

The tubular member I65 is arranged in a cyl- The tubular member I65 is similar to the tubular member 42 previously described and the cylinder I61 is similar to the cylinder 20 previously described. The cylinder I61 is secured to the base I2 by a flange I68 and bolts I69.

Within the cylinder I61 and within the tubular member I65 I show a column I which is similar to the column 58 previously described. The tubular member I65 includes a piston head III with annular packing member I12 and I13 therein which engage the inside of the cylinder I61 and the outside of the column I10 respectively. The packing members I12 and I13 are held in place by a clamping plate I14 which is secured to the piston I1I by bolts I15. The column I10 is open at its upper end as at I16 and beneath the open end includes a piston head I18 and a packing I19 held on the piston head by bolts I80. I

The column I10 is connected by a conduit "II with a valve I82 which is similar in all respects to the valve 15, previously described. The valve I82 communicates through a conduit I83 with a pump I84. The pump communicates with a conduit I85 which also communicates with the valve I82. The conduit I83*-constitutes the pump out let and the conduit I85, the pump inlet.

The valve I82 communicates through a conduit I86 with the lower portion of a container I81 which container is similar to the hollow Samson post previously described. The container I81 includes a partition I88.

When the valve I82 is in the position shown in Figs. '1 and 8, liquid is drawn from the container I81 through conduit I86, valve I92, conduit I85, pump I84, conduit I83, valve I82, conduit I8I and into the column I10, whence the liquid acts upwardly against the end closure I6I thus urging the walking beam upwardly.

When the valve I82 is rocked by the rod I89 flow of liquid proceeds downwardly through the column I10, conduit 'I8I, valve I82, conduit I83, pump I84, conduit I85, valve I82, conduit I96 and into the container I81 where air above the entering liquid is compressed.

The pump I84 is driven by a belt I90 from a pulley I9I driven by a motor I 92.

An air compressor I93 is driven by a belt I94, The intake pipe I95 of the engine and the intake I96 of the compressor communicate with a pipe I91 which opens into the upper portion of the cylinder I61, so that a partial vacuum is created in the space I98 between the tubular member I65 and the inner wall of the cylinder I61. This partial vacuum acts upon the top portion I99 of the piston head -I1I thus tending to raise the piston head and the tubular member I65. The intake pipe I95 includes a check valve 290 which prevents passage outwardly from the engine while the pipe I91 contains a valve 20l which opens when the partial vacuum in thepipe I91 drops below a predetermined amount. The motor exhaust pipe 202 communicates with the lower portion of the cylinder I61 and delivers the heated products of combustion into the lower portion of the cylinder and the pressure of these gases aids in forcin the piston I1I upwardly.

The outlet pipe 203 from the compressor communicates with a valve 204 which is similar to the valve I05 previously described. The valve 204 is part of a system which is similar to the system shown in the embodiment first described and in this modificationsimilar parts have been designated by similarly primed reference numerals.

In the operation of the device in the modification, when the motor I92 is started, the pump I64 and the compressor 9 I93 are actuated. Liquid, which is in the system which includes the valve I82, is pumped back and forth between the interior of the upper end of the tubular member I and the lower portion of the container I 81.

During this operation air is compressed in the upper portion of the lower part of the container I81 beneath the partition I88 and is periodically discharged into the lower portion of the cylinder I61 through the conduit 88. Air from the compressor is also periodically discharged from the tank I08 through the sam conduit 88'. Exhaust gases from the engine I92 are also discharged into the lower portion of the cylinder I61. At the same time a partial vacuum is created in the upper portion of the cylinder so that all of these fluids serve to raise the tubular member I65 and thus lift the pin I62 to thereby rock the walking beam I5I. The lengths of th parts as shown in Figs. 7, 8 and 9 are such that the lift of the cable I53 is substantially twice the movement of the tubular member I65, so that my modified structure produces a long stroke pumping eflect. To subject the space I11 to a partial vacuum, the tubular member includes a hole 205 in the lower portion thereof.

In Fig. 10 I show a further modification of my invention. The further modification is similar to the modification disclosed in Figs. 1 to 6 inclusive and described above. In the further mod-'- ificatlon similar parts are designated by similar double primed reference characters. In the further modification the engine 22 is omitted and in place thereof I show an electric motor 200. This motor by means of a belt 20I drives the pump 12".

Having thus described my invention, I claim:

1. In a well pumping device, a hollow tubular supporting post, a walking beam pivotally mount ed intermediate its length on the post, a substantially'verticalcylinder .adj acent to one end of the beam, a piston slidably mounted in the cylinder, said piston including a head portion within the cylinder and a tubular portion, said tubular portion being spaced from the cylinder and projecting beyond the upper end of the cylinder, the upper end of the tubular portion being closed, means pivotally connecting the projecting portion to the walking beam, a'hollow column in the piston tubular portion and spaced therefrom, means to support the hollow column, said column having a closure at the upper end thereof, said closure including a head portion which slidably receives said piston tubular portion, said closure being spaced from the upper end of the tubular portion, said column having an outlet to the space between the column and the piston tubular portion, conduit means connecting the interior-of said column and the lower portion of said post, said conduit means including a pump and a four way valve, means operated by the walking beam to actuate the four way valve so that fluid is alternately moved from the post to the column and vice versa, means whereby passage of fluid into the post compresses air in the upper portion of the post, pipe means to direct air compressed in the upper portion of the post to the upper portion of the cylinder, a valve in said pipe means and means operated by the walking beam to actuate said last mentioned valve, a source of suction, and means to connect the portion of said cylinder below the piston to the source of suction.

2. In a well pumping device, a hollow tubular supporting post, a walking beam pivotally mounted intermediate its length on the post, a substantially vertically arranged cylinder adjacent to one end of the beam, means to pivotally support the lower end of the cylinder, a piston slidably mounted in the cylinder, said piston including a head portion and a hollow piston rod, said rod being spaced from the cylinder, said hollow piston rod projecting above said cylinder, a closure on the upper end of the piston rod, means pivotally connecting said piston rod to the walking beam, a hollow, fixed column arranged in the piston rod and spaced therefrom, a piston head mounted on said hollow column, said piston head working in said hollow piston rod, said column having an outlet to the space between the column and the hollow piston rod, a container, a conduit connecting the interior of said column and said container, means communicating with said conduit to alternately move fluid from the container to the interior of the column and vice versa, means whereby passage of fluid into the container compresses air in the upper portion of the container, means to convey air compressed in the upper portion of the container to the space between the hollow piston rod and the cylinder and means to force fluid under pressure into the space between the piston rod and the cylinder.

3. In a well pumping device, a hollow tubular supporting post, a walking beam pivotally mounted intermediate its length on the post, a substantially vertically arranged cylinder adjacent to one end of the beam, said cylinder having a closure at the upper end thereof, said cylinder having a closure at the lower end thereof, means engaging the lower end closure to pivotally support the cylinder, a piston slidably mounted in the cylinder, said piston including a head portion within the cylinder and a tubular portion projecting upwardly from the piston and spaced from the cylinder, said upper end cylinder closure having a central aperture, the projecting portion of said tubular member extending through said aperture,

means closing and connectin the upper end of said projecting portion to the walking beam, a hollow column in the tubular piston portion and spaced therefrom, said column having a closure on the upper end thereof, a piston head mounted on said column closure, said piston head working in said piston tubular portion, said column closure being spaced from the upper end closure of the tubular portion, said column having an open outlet to the space between the column and the piston tubular portion, a container, a conduit connecting the interior of said column and said container, means communicating with said conduit to alternately move fluid from the container to the interior of the column and vice versa, and means to force fluid under pressure into the space between the tubular portion and the cylinder.

4. In a well pumping device, a hollow tubular supporting post, a walking beam pivotally mounted intermediate its length on the post, a substan tially vertically arranged cylinder adjacent to one end of the beam, said cylinder having a closure at the upper end thereof, said cylinder having a removable closure at the lower end thereof, means engaging the removable closure to pivotally support the cylinder, a piston slidably mounted in the cylinder, said piston includin a head portion within the cylinder, and a tubular portion projecting upwardly from the piston, said tubular portion being spaced from the cylinder, said upper end cylinder closure having a central aperture, the projecting portion of said tubular member extending through said aperture, a closure on the upper end of the projecting portion of the tubular member, means pivotally connecting said upper end tubular portion closure to the walking beam, a hollow column in the tubular piston portion and spaced therefrom, said removable closure having an aperture through which said column extends, said column having a closure on the upper end thereof, a piston head mounted on said column closure, said piston head working in said piston tubular portion, said column closure being spaced from the upper end closure of the tubular portion, said column having an open outlet to the space between the column and the piston tubular portion, a container, a conduit connecting the interior of said column and said container, means communicating with said conduit to alternately move fluid from the container to the interior of the column and vice versa, means to convey air compressed in the upper portion of the container to the space between the tubular portion and the cylinder and means to force fluid under pressure into the space between the tubular portion and the cylinder.

CONRAD R. BUCHET.