US2728193A - Ram jack - Google Patents

Description

Dec. 27, 1955 R. BACCH. 2,7 8, 93

RAM JACK Filed July 7, 1953 4 Sheets-Sheet l 7 %ww KW Dec. 27, 1955 R. BACCHI 2,723,193

RAM JACK Filed July 7, 1955 4 Sheets-Sheet 2 INVENTOR. 6W 54cm Bl wfw R. BACCHI Dec. 27, 1955 RAM JACK 4 Sheets-Sheet 3 Filed July 7, 1953 INVENTOR. in) 54mm irram n Dec. '27, 1955 R. BACCHI 2,728,193

RAM JACK Filed July 7, 1953 4 Sheets-Sheet 4 INVENTOR. 94/ 546667 lrrap/vir Unit tats RAM JACK Ray Bacchi, Daly City, Calif., assignor to The Pelton Water Wheel Company, a corporation Application July 7, 1953, Serial No. 366,506

6 Claims. (Cl. 60-51) Various kinds of pumping jacks are utilized for the purpose of actuating pumps and hydraulic jacks make up a large proportion of the structures utilized practically. in most instances hydraulic jacks are relatively complex and expensive and are not economically suited for use on wells which are relatively small producers.

It is therefore an object of the invention to provide a ram jack of relatively simple construction and design which can be economically made and is applicable especially to pumping wells which are relatively small producers.

Another object of the invention is to provide a ram jack which can be moved from time to time to different wells to be pumped.

A still further object of the invention is to provide a ram jack having good control of the pumping stroke without the necessity of utilizing delicate or expensive control mechanisms.

A still further object of the invention is to provide a ram jack operating at a relatively low pressure so as to use a relatively economical oil pump.

A still further object of the invention is to provide a ram jack in which the stroke of the pumping unit can be readily regulated to any desired value within wide limits.

A still further object of the invention is to provide a ram jack which does not involve a substantial superstructure with heavy machinery far above the ground, but rather a structure in which the machinery is located and the weight is concentrated close to the ground.

Other objects, together with the foregoing, are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings in which:

Figure l is a side elevation of a ram in accordance with the invention.

Figure 2 is a side elevation similar to Figure l but showing to an enlarged of Figure 1.

Figure 3 is a plan to the scale of Figure 2 of the ram jack of the invention.

Figure 4 is a front elevation of the upper portion of the ram jack, the scale being the same as in Figures 2 jack constructed scale the upper portion of the ram jack and 3, with some portions of the figure broken away to reduce its size.

Figure 5 is a diagram showing the piping arrangement of the ram jack.

While the ram jack of the invention can be embodied in a number of different ways depending partly upon the environment in which it is to be generally utilized and depending upon various manufacturing techniques, it has successfully been incorporated in an arrangement as described and illustrated herein. In that embodiment, the

structure is for use primarily with an oil well 6 (Figure 3) of the customary kind extending from the surface of the ground 7 and having a polish rod 8 extending down the well to a pump (not shown) for discharging the contents thereof. Reciprocation of the polish rod 8 through a suitable stroke operates the pump within the well.

In accordance with the invention, the ram jack includes a pair of skids 9 and 11 designed to rest upon the ground and to be readily moved thereover from place to place as the jack unit is utilized with diiferent wells from time to time. The skids 9 and 11 serve as a foundation for a pair of substantially identical ram cylinders 12 and 13. The bases of the ram cylinders 12 and 13 are detachably connected by fasteners 14 to the respective skids 9 and 11 and are each located alongside of and together straddle the oil well 6.

The cylinders are closed at the bottom and extend upwardly to an open top. On the upper portion of the cylinders, there are provided reinforcements 16 and 17 carrying structural pads 18 and 19. Extending between the pads and removably connected thereto are bridge members 21 which serve as structural connectors and, having substantial depth, also as stiffening members. These secure the cylinders 12 and 13 in fixed relationship so that the assembly of the cylinders with the skids and the bridge members forms a good, substantial structure.

As an additional stiffener, the skids 9 and 11 are spanned at their ends opposite the cylinders by an intervening oil sump tank 22 firmly secured to the skids and extending upwardly to serve as a base for a pair of braces 23 and 24. These are constructed of structural shapes, at their lower ends secured by appropriate fasteners to the tank 22 and at their upper ends secured to the pads 18 and 19. The braces 23 and 24 are at intervals spanned by rungs 26, serving not only as additional braces, but also as an access ladder to the upper portion of the ram unit. The assembly is therefore a rigid, although light, structure with much of the weight concentrated reasonably close to the ground.

The cylinders 12 and 13 receive rams 28 and 29 or plungers at their upper ends connected together by a tie beam 31 having sockets 32 and 33 at its extremities fitting over studs 34 projecting from the rams 28 and 29 and detachably held in position by suitable nuts 36. The rigidity and spacing of the rains 28 and 29 is maintained because of the stiffness and depth of the tie beam 31.

The rams 28 and 29 are adapted to reciprocate within the cylinders 12 and 13 and are flexibly connected to the polish rod 8 by an equalizing structure. This includes a pulley 37 mounted on a cross shaft 38 secured in blocks 39 on the tie beam 31. A cable 41 is trained around the pulley 37 and its opposite ends depend between the bridge members ,31 and are secured by cable clamps 42 and 43 to a fastener 44 at the upper end of the polish rod 8.

[Any minor misalignment or irregularity in the motion of the rams 28 and 29 is compensated for by the cable 41. Thus the polish rod 8 is subjected to reciprocating forces only without any substantial side thrust in any direction.

The weight of the pump in the well, the weight of the polish rod 8, and the weight of the rams 28 and 29 and all of the interconnected structure, is imposed upon fluid within the ram cylinders 12 and 13 and, in accordance with the invention, there are provided means for governing the flow of hydraulic fluid into and out of the cylinders 12 and 13 to provide the desired reciprocation of the polish rod 8.

The sump tank 22 contains a charge 51 of actuating liquid, preferably oil substantially free of contaminants, such as gas, air or Water, and hence serving as a substantially solid, force transmitting medium. The oil sump tank 22 is provided with a clean out plate 52 for ready access to the interior and is also connected by a vent 53 to the outside so that the pressure inside the sump tank is that of the atmosphere.

Leading from the body of oil 51 in the sump tank 22 is a pipe 54- extending to the inlet 56 of a relatively inexpensive and compact pump '57, either positive displacement or centrifugal, and having an outlet 58. The pump is conveniently mount-ed on a bracket 59'utilizing the sump tanl; 22 as a base. The drive shaft 61 of the pump 57 is provided with a pulley 62 connected by belts 63 to the pulley 64 of a driving motor 66. As shown, thismotor is electrically impelled and is mounted on anadjusting base 67 extending from the oil sump tank 22 as a support. In other installations, the electric motor 66 is replaced by an internal combustion engine or the like, it being only necessary to adapt the base 67 and the drive *structurefor "that purpose. The motor 56 drives the pump 57 at substantially a constant speed depending upon the upstroke pumping speeddesired,theamount-of power consumed by the motor "66 depending 'upon whether the pump 57 is pumping fluid against a high pressure or is running substantiallyidleagainst a low pressure.

"From the outlet-58 of the pump 57 an extensive conduit68 extends ultimatelytothe baseofthe'jack cylinders 12 and 13, the "terminal part of thecondtiitfiSbranching to forms connector "69 tothe cylinder 12 and a connector 71 to the cylinder Throughout its extent, the .conduit 68 is entirely-open to the cylinders '12and 13 except that adjacentthe outlet 58 of the pump 57 there 'isinterposeda checkvalve 720i thecustomary kind arranged'so that, while it permits flow away from'thev;pump58,it precludes flow back through the conduit 68 toward the pump 57.

The pump 57 is continuously rotated and is effective to take oil 51 from the sump tank 22 at atmospheric pressure and to increase the oil pressure suiiiciently'to displace the rams 2S and 29 upwardly from the cylinders 12 and d3. To work with the pump, there is provided in accordance with the invention, 'a mechanismior controlling the llow ot'oil to and from the cylinders in such a tashion'that the rams reciprocate appropriately.

'For that reason, there leads oil from'theconduit '68, between the check valve 72 and the branches 69 and 71, a shunt pipe 73 passing through a main'valve 74 and extending ultimately to the sump tank 22. A valve shuttle '76 in the main valve 74 is efiective in the position'shown in-Figure 5 to permit flow'through the shunt pipe 73 from the conduit 68 through a pressure relief valve 77 and through the remaining part of the shunt pipe 73 back to-the sump tank 22. The pressure relief valve 77 incluclesa plunger 78'having a spring 79 efiective to oppose the pressure of the fluid acting uponthe piston 78 and, when overcome, to permit the translation of the piston78 to-uncover a port 81 so that the shunt pipe is then continuously-open. The efiect of the pressure relief valve 77 isto preveutexcess pressure in the shunt pipe ahead of that valve.

The piston'76 of the main valve 7 4 has another, opposite .position. In this location, while-the shunt pipe 73 isstill open, there is also'opened, by displacement of the piston 7'6, -an:alternate path to the sump tank 22 througha return .pipe 82. ln the return pipe 82 is dispose'dahand operated valve 83 so'that'the return pipe can berestricted as desired to control the downstroke speed of the rams '28 and 29.

The main valve7-l is provided with a hydraulic actuator in that the piston 76 atone end is provided with a return spring 84 opposing pressure on the piston 76 communicated thereto through a tube 86 extending from the main valve 74 to a control valve 87. From the control valve 87, the tube 86 extends to a junction 88 with the conduit 68 so that Whencircurnstances are appropriate, hydraulic fluid under'pressure in the conduit 68 flows through the tube 86 and through the control valve '87 to. the main valve 74,'and .'if the pressure ishigh enough, overcomes the urgency of'the spring '84 and displaces the,piston-76 to open the shunt pipe 73, not only to its indirect return through the pressure relief valve 77 to the sump tank, but also to the return pipe 82 open directly to the sump tank.

interposed in the tube 86, between the junction 88 thereof with the conduit 68 and the control valve 87, is a check valve 89 effective to permit the flow from the junction 88 and the conduit 68 toward the control valve 87 but to prevent backflow in the reverse direction. Also open to the tube 86 between the check valve 89 and the control valve 37 is a hydraulic accumulator 91 joined by a short pipe 92 to the tube 86. This accumulator is of the customary kind and involves a chamber of air or other elastic arrangement effective upon the liquid within the lower part of the accumulator to maintain pressure within the tube 36 when other sources of pressure are ineffective.

The control valve 87 includes a ported valve body 93 to which the various pipe connections are made and is also connected by a drain line 94 extending directly to the oil sump tank '22. Within the control valve is a rotary plug 96 having a bore 97 therethrough. This is effective to establish communication between the tube 86 and the drain line'9 l, in the position shown in Figure 5, or, man

alternative position, is effective to establish communication between the several parts of the tube 86 to permit free flow therethrough. In this position the drain line 94 is iso- 'lated.

Theplug96 is rotated between its two extreme positions by the joint operation of a pair of radial extensions and 99 projecting at difierent polar attitudes from the plug and being'displaced axially of-the plug. The extensions98and'99 (Figure 4) are disposed to lie on opposite 'andsecured by suitable'removable fastenings 104 are cams 106 and 107, "respectivelydesigned to travel inpaths into "which the extensions-98 and 99 project.

The effect of the cams on the travelling T-bar 101 is'to 'engagethe extensions 98 and 99-at the opposite etxremities 'of 'the reciprocating movement of the rams 28 and 29 and to actuate the-valve plug 96 accordingly. Since the- cams 106 and 107 can be disposed in any position desired within the length'of the T-bar 101, thestroke of the rams can be regulated in amount and can also be regulated in position.

In'the operation'of'this structure, the oil pump'57runs continuously so that fluid is discharged under pressure intothe conduit 68 and past the check valve 72 andthrough the branches 69 and 71 into the bottom portions .of the cylinders 12 and 13. At-the same time, fluid can flow through the shuntpipe 73 and through the main valve 74 -to the pressure regulating valve 77. The strength ,of' the spring 79 is such that the valve 77 does not open at the normal pressure necessary to lift the rams 28 and 29 within the cylinders. The pressure reliefvalve77 opens 0nly -inthe eventsomething should gowrong with the'rnachinery and the rams'shouldarrive at the'end'of'their possible stroke without reversal or should otherwise become jammed or stuck.

Liquid within the conduit 68 can'also travel through thecheck valve-"89 into the accumulator 91 to charge it to .the'system pressure, with the fluid pressure also being communicated through the remainder'of the=tube 86 to the control valve 87. When the valve isin the position shown-in Figure 5,-thejfiow stops at that point. "Conse- .in Figure .5, thereby-moving the valverotor 96- into-its other position.

In-this otherzposition, the drain'line 94 is cut off and communication is established between the two portions of the tube 86. The pressure stored in the accumulator 91 is efiective to cause flow into the end of the main valve body 74 and to displace the valve spool 76 upwardly, in Figure 5, against the control spring 84 and to open the tube 68 to the return pipe 82, the valve 83 being open for this purpose. The pressure within the shunt pipe 73 and the return pipe 82 then drops immediately to atmospheric pressure or fliereabouts so that the pressure within the conduit 68 also drops substantially to atmospheric. Backfiow from the tube 86 is prevented since the check valve 89 closes and the necessary hydraulic fluid to actuate the main valve is derived primarily from the accumulator 91.

Since the pressure within the conduit 68 drops substantially to atmospheric, the weight of all the parts on the rams is imposed upon the fluid in the lower portion of the cylinders 12 and 13 and is expelled by reverse flow through the conduit 68 and through the shunt pipe 73 and into the return pipe 82 back to the sump tank 22. Although the pump 57 is continuously revolving, it needs to pump only against the substantially atmospheric pressure in the conduit 68 during the return part of the cycle.

In the event of electric power failure, the return flow builds up of a sufiicient pressure to drive the pump 57 backwardly and to permit a too rapid return of the oil. Should backflow start, the check valve 72 closes so that the pump 57 is not driven as a hydraulic motor and no oil short circuits.

The lowering or return cycle continues until such time as the rams 28 and 29 have descended sufficiently for the cam 106 to strike against the extension 98 and to revolve the valve plug 96 back again to the position shown in Figure 5. The main valve 74 is thus immediately opened through the tube 86 to the drain line 94 and the spring 84 is effective to displace the valve spool 76 back into the position shown in Figure 5 with the return pipe 82 blocked and the shunt pipe 73 open to the sump tank 22 only through the pressure relief valve 77. When the valve spool 76 is translated into the Figure 5 position, there is no other escape for the output of the pump 57 and the pressure in the conduit 68 then rises again to lift the rams upwardly. When the pressure increases in the conduit 68, there is flow from the junction 88 into the tube 86, at least in a sufiicient amount again to charge the hydraulic accumulator 91 up to the normal upstroke pumping pressure of the pump 57.

As the rams arrive at their uppermost position, the control valve 87 is again actuated and the cycle is indefinitely repeated as described.

In the event, upon shutdown, the rams are near the upper part of their stroke and it is desired to lower them for any reason, it is possible without disturbing the pressure relief valve 77 to accomplish that end. This is achieved by permitting flow through a duct 108 extending from the shunt pipe 73 to the sump tank 22 under control of a hand valve 109. Normally the valve 109 is closed but when it is open, then flow to atmospheric pressure can readily occur from the conduit 68 through the shunt pipe 73 and through the duct 108 even though the pressure relief valve 77 is still closed. Before starting the ram unit again, the valve 109 is closed. By appropriate manipulation of the valve 109, the ram unit can manually be made to short stroke or to operate entirely at the will of the user.

In accordance with the invention, there has been provided a ram unit which is readily movable on its skids from one well to another, is readily connected by flexible cable to the polish rod and is effective because of the dual ram straddle mounting to impose substantially equalized hydraulic forces on the polish rod. The ram unit is relatively low in height because of the inverted open ended cylinders, yet is well aligned and is a stiff structure. It operates through the medium of a relatively inexpensive pump having an automatic control system incorporating a hydraulic accumulator. This insures that the hydraulically actuated main valve is always provided with sufficient operating fluid and pressure, yet the entire hydraulic structure, as well as the mechanical structure, is relatively simple, straight-forward and economical.

What is claimed is:

l. A ram jack comprising a ram cylinder, a ram reciprocable in said cylinder, an oil sump tank, an oil pump, a pipe leading from said sump tank to the inlet of said pump, a normally continuously open conduit leading from the "outlet of said pump to said ram cylinder, a shunt pipe extending from said conduit to said sump tank, a main valve in said shunt pipe and movable between an open position and a closed position, a hydraulic operator for moving said valve between said positions, a tube leading from said conduit to said hydraulic operator, a control valve in said tube, and means on said ram for operatingsaid control valve.

2. A ram jack comprising a ram cylinder, a ram reciprocable in said cylinder, an oil sump tank, an oil pump, a pipe leading from said sump tank to the inlet of said pump, a normally continuously open conduit leading from the outlet of said pump to said ram cylinder, a shunt pipe extending from said conduit to said sump tank, a main valve in said shunt pipe and movable between an open position and a closed position, a hydraulic operator for moving said valve, a tube leading from said conduit to said hydraulic operator, a drain line, a control valve in said tube and having two positions in one of which said tube is open to said hydraulic operator and in the other of which said conduit is blocked from said operator and said operator is connected to said drain line, and means dependant upon the position of said ram for operating said control valve.

3. A ram jack comprising a ram cylinder, a ram reciprocable in said cylinder, an oil sump tank, an oil pump, a pipe leading from said sump tank to the inlet of said pump, a conduit leading from the outlet of said pump to said ram cylinder, a shunt pipe extending from said conduit to said sump tank, a main valve in said shunt pipe, a hydraulic operator for said valve, a tube leading from said conduit to said hydraulic operator, a check valve in said tube blocking flow toward said conduit, a hydraulic accumulator in said tube between said check valve and said operator, a drain line extending to said sump tank, a control valve in said tube between said accumulator and said operator, said control valve having two positions in one of which said tube is open to said hydraulic operator and in the other of which said hydraulic operator is open to said drain line, and means on said ram for operating said control valve.

4. A ram jack comprising a ram cylinder, a ram reciprocable in said cylinder, an oil sump tank, an oil pump, a pipe leading from said sump tank to the inlet of said pump, a conduit leading from the outlet of said pump directly to said ram cylinder, a shunt pipe extending from said conduit to said sump tank, a main valve in said shunt pipe, a hydraulic operator for said valve, a tube leading from said conduit to said hydraulic operator, a check valve in said tube blocking flow toward said conduit, a hydraulic accumulator in said tube between said. check valve and said operator, a drain line extending to said sump tank, a control valve in said tube between said accumulator and said operator, said control valve having two positions in one of which said tube is open to said hydraulic operator and in the other of which said hydraulic operator is open to said drain line, a check valve in said conduit between said pump outlet and said shunt pipe blocking flow toward said pump outlet, and means eiiective in the two extreme reciprocated positions of said ram in said cylinder for correspondingly positioning said control valve.

5. A ram jack comprising a ram cylinder, a ram reciprocable in said cylinder, an oil sump tank, an oil pump, a pipe leading from said sump tank to the inlet of said pump, a normally continuously open conduit memes leading from the outlet of said purnp .Iosaid ltamicylfind r, .a *Shlln pipe ex ending from sa deonflnit to sai sump flan a main vvalve in sail hs unt p pandm a -between an open position and a closed position, :a hyduit, and means on said tram for operating said control valve.

6. A ram jack comprising a ram cylinder, a ram rec'iprocable in said cylinder, an oil sump tank an oil pump, a pipe leading from said sump tank to ,the inlet of said pump, a normally continuously open conduit leading from the outlet of said pump to said rarncylinder,

a shunt ,pipe extending from said conduit to said sump tank, a main .valve insaid shunt pipe and movable between an open position and axclosed position, a hydraulic opera o vfo .nming a d v l e, .a tu lead g l p a d qn diii to said .ihyd oper tor a dra line a con ro v v fi .s i tub an vin 1 0 position i on of wh chl ai tu 99 1 i hyd a l Q9- erato an in the th o wh c sa d n ui -i b c fl from saidtoper'ator and said "operator 'is connected "to said drainli ne, a check valve fin said tube between said conduit and said valve for preventing flow ,toward said conduit, an'd neans dependent upon theiposition of said ram {for operatingsai'd control valve. 4

References Cited inthe file of this patent "UNITED STATES PATENTS ,6 9 4 ub r --t-.- i a 9 2,019,353 :Lower Oct. '29 193.5 2,555,426 Trautman June 5, 1951 2,555,427 "Trautrnan o June 5, "195,1

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