US1665639A - Tandem single-acting pump - Google Patents

Description

April l0, 1928. 1,665,639

E. W. PATTERSON TANDEM SINGLE ACTING PUMPv Filed Marh 30. 1926 2 SheBtS-Shee l April 10, 1928.

E. W. PATTERSON TANDEM SINGLE ACTING PUMP 2 4Sheets--Sheet 2 Filed March ESO. 1926 l lf Patented Apr. 10, 1928.

uuiiun siArEs EDGAR "N. PATTERSON, OF LONG BEACH, CALIFORNIA.

' TANDEM SINGLE-ACTING PUMP.

Application filed March 30, 1926*, Serial No. 98,442.

My invention. relates to the oil producing j industry, and it relates particularly to an oil pump.

After a well has been drilled and the oil string is set into place, an oil pump consisting of a pump barrel and a pump plunger is vplaced near the bottom of the well, the pump barrel being attached to the lower end of a pump tubing which extends upwardly through the oil string to the surface of the ground. The pump plunger is attached to the lower end of a string of sucker rods which extends upwardly through the lpump tubing `and which is connected at its upper end to a walking beam of the derrick of the well, whereby it is reciprocated and whereby the pump plunger is reciprocated in order to velevate oil throughthe pump tubing to the surface of the ground. j

Obviously, it is advantageous to have as large a. pumping capacity as possible. Different inventors have endeavored to increase the pumping capacity in a well by providing a double acting pump, that is, a pump which works on its down stroke as wellas onv its up stroke. Double acting pumps, however, are not satisfactory due to the fact that it is substantially impossible to furnish power on the down stroke, this being due to the fact that the sucker rods are of smaller diameter and are very vlieirible.

My invention consists of a single acting pump which comprises two pump units which are placed. in tandem with each other.` Each pump consists of a barrel and a plunger and each pump unit has a separate intake; beth the pump units, however, introduce the oil into the pump tubing which supports the pump. Both of the plungers of the two units are operated through the saine string of sucker rods.

lt is accordingly an object of this invention to provide a single acting pump having substantially twice the capacityY of the comi mon form of oil well pump.

It isnecessary to remove the plunger of a pump for the purpose of repair or inspec tion and it is highly desirable that the pump be so constructed `that the plunger may be elevated to the surface of the ground without removing the barrel from place. This is desirable since to remove the barrel from the well, it would be necessary to uncouple eachl the two units are secured together. Inside this connector is a plug which separates the spaces of the two barrels so that they may operate independently. The connector vis formed in such. almanner that it may be engaged by one of the plungers of the pump and actuated in such a manner that itmay be removed from place. By this 'provision tliepump plungers of my invention lmay be removed to the surface of the ground without removing the barrel.

lt is accordinglyanother objectofmy iny vention to provide a single acting tandem pump of the character described in which the plunger structure may be removed to the surface of the ground without l.removing the barrel from the well.

VOther objects and advantages of the invention will be made evident hereinafter.

Referring to the two sheets of drawings in which I illustrate a invention,

Fig. 'l is a vertical section taken through the upper part of the pump of my invention. Fig. 2 is a vertical section taken through the lower part of the pump of my invention.

preferred form of my Y Fig. 3 is a section taken on the line 3--3 i of Fig. l. j v j Fig. lis a section taken on the line 4:-4 of Figi. j,

Fig. 5 is a section taken on the line 5-5 of Fig. 1.

Referring to the drawings, the pump of my invention has an upper barrel ll and a lower barrel 12which are joined together by a connector13. The upper barrelll has a jacket 15, the upper end of which is screwed at 1G into an uppercollar 17 and the lower end of which is threaded into athreaded cavity 18 formed at the upper end of the connector 13. The upper barrel 11 also includes a liner 19 which is enclosed and protected by the jacket 15 and which is held in place vbetween a shoulderQO of the upper collar 17 and a shoulder 2li of the connector 1B. The lower barrel 12 consists of a jacket 24:, the 4upper end of which is screwed into a threaded cavity Q5 formed at the lower end of the connector 13. The lower end ofthe jacket 2li screwed into a threaded cavity 27 formed at the upper end of a lower collar 28. The lower barrel'll has a liner 29 which is held between a shoulder 31 ofthe connec tor 13 'and a shoulder 32 of the lower collar Q8. The lower collar 28 provides a conical seat 34V which is engaged by e conical face 35 3048 "and to the'up'per end ot the plug.

of a Standing valve body 36 which has a passar/rc3?" formed therethrough.' Connected to the upper part of the standing valve body 36 is a standing valve cage 39 `which"enshrouds a standingvalve ball 40 adapted to 1@"purrfip is closed. The', body 36, the cage 39,

40:,and the seat 41 form a standing f valve. for lthev lower barrel 12'. `'llheoonneotor .1 3.has an opening '43 formed therethrough Iainrvvhich afphig44 isplaced. rllhis plug 44 15j1sprovided .fo1 ftlie` purpose of separating II'theinteriorsV of the upperand lower barrels .1-1 and112'." iThe plug 44 is secured in place Vtfhreaded engagement `with the connector 13, a's'shown'at 45. "The threadstorined at y45are`left hand threads whereas it is cusltoniaryfin oil punipv construction' to provide lrightlhand'threads. The p'urposeof this "will be explained hereinafter.

" Radialopeningsuif? lconnect the exterior ofthe connector 13 to anannular channel 48 whichsurrounds the opening 43 in the connector 13'fnearV the central' part thereof. .Passages are orrned in the plug 44. these 'passages loo n'necting yto the lanrnilar channl packing 50 is provided between the plug 44 and connector`13 above the annular chanq nel48, an'dfa packing 51 is provided between .the plug'and connector below the annular 35 48to prevent any leakage. T he upper end of the plug 44 is hardened to form a s tanding valve seat 53. `rllhreadedly se- "curedat 54to the upperend of the plug44 isi an upper standing `valve cage 56 having 141 a chamber 57 in which a standing valve 58 isplaced. The standing valve 58 ring typefof valv@y having a. central opening 59. 'Ilie valve 58 is adapted tojenga'ge the seat 53i`and :close the passages 49 which entend through the plug 44. rlhe seat 53, the cage Q56 and'thevalve 58 provide "a standing valve [for the upper barrel 11. Adapted to operxate inthe upper barrel 11 is an upper plunger .61"and 'adapted to operatein the lower t, barrel `12is a lower`plunger 62. Connect- V'ing theupper andl lower plungers together 'is' a plungertub`ef65` This plunger t-ube`65 'entencl's`-tlirotigh an opening 66 formed `in fthe'"plug'y 44. .It also' extends through .an opening' orniedin theupper lstanding `valvecage56 and through the opening 59 ffthefupper standingvalve 58. The lower ypart theplug44 is provided with a stuffboX`}6 8,this' jstuiting loonA consisting of paclingt) which is fcoinpressedby a foll ower' `70;fthis follower 7 0 being engaged by fannutw 1 which is screwedl into the lower end ofra e'avity 2er the plug 44 in which the "stuftfingbox is located. This stuffing box 68 provides' a tight seal around the plunger tube but permits it toreciprocate as will be described shortly. The lower end of the plug 44 is provided with projections 74 as i shown clearly in Fig..1.

The upper puinp plunger 16 includes a seat buehing y77 which surrounds the upper end Aoftheplunger tube 65 and which is lthreade'dly secured thereto as indicated at 8. The upper end ot thev seat bushing 77 ienhardened to 'provide an upper traveling "valve "seat 79. Threadedly secured 'atl'80 y towthepseat bushing 77r is an upper traveling valvecage 81 having chainber 82 in which an lupper traveling valve 83 yis placed.l The "up'perl traveling valve :83 is a ring` type ot' 'valvehaving an 'opening 84 'formed therethrough. The valve 83'is adapted to engage thef'seat 791er closing passages o5 formed hrorugh thefbushingWT. he upper end of "'tljie'plunger tube '65 extends 'through the Vlooening84 of' the valve 83 Iand through an zopening 86 'of the cage 81. 'The upper end ot'lzuiupper plunger sleeve 87 is secured Le688 to the seat bushing 77. r:The lowereud of the` upper plunger sleeve 87 hasa'centralfizilngbusliing 89 screwed thereto, as indicated The" eentralizing bushing 89 has an opening 92 forined ztherethrmugh througl'i "which the vplunger tubey 65 entends. Passages f 93are orn'ied through the centralizing bushingr89, these surrounding the plunger5 tubell and permitting' the passage o'l oil byfthe'eentralizing bushing 89. A bushing 'is threadedly secured at 97 to the 'lower end' ofthel -plunger tube 65, this bushing 96 apassage 98`Vwhich connects the kpassage"ofthe plunger tube G5 with the invfvtferior of thelowerbarrelv 12. The bushing hasy passages which are in circulaiarrangeinent around'the lower en d of the p hingertube 65,' which'perniit a vpassage of oil from' one sideto the other thereof. The uppeii'partoit the bushing 96 ie provided lwithprojections' 101 vseparated by spaces "140,2". The projections 101 are adapted to en- `gage the projections 74: orinterlocking the lower plunger`62 to thefplug 44 so that the plug 44 may be rotated,as will be deecribed hereinafter. A' lower plunger sleeve 104- is threadedly secured at 105 to the bushing 96, `)The.l'owerend of the lower plunger sleeve 104 is' ythreadedly connected' at 1.67 to the upper end of lower traveling valve cage 108. .The traveling valve cage 108 provides a chamber "109 in 'which a lower `traveling yya'lveiiln the `forni oi' a ball'110 is situated. A lower traveling valve'seat 111 having a l passage 112 torined therethrough is secured to fthe lower part of the cage108 by means or a `nutV 113;v The ball v110 may engage the seat 111 for 'closing the passage 112 formed therethrough. The extreme 'upper end of the plunger vtube 65 threadedly receives a 'toraininous cap 115. This c'a-phas a cage portion 116 formed upon a threaded collar 117, which screws upon the threads 78 ofthe tube65. Thevcage portion 116 has openings 118 therein throughwhich oil may,

escape from the tube`65 and pass upwardlyA into the pump tubing 120. The upper end of the cage 116 is provided witha threaded pin118, by means of which the plunger as sembly may be attached to the lower end of a string of sucker rods such as is provided in ordinary equipment in the usual oil apparatus. i

The operation of my invention is substany tially as follows:

into the lower end of the upper barrel 11.` The ball 110 is in engagement with the seat 111 so that oil in the lower barrel 1Q above the lower traveling valve will be moved upwardly with the plunger assembly: the valve 83is in engagement with the seat 79 so that f oil in the upper barrel 11 above the valve 88 will be moved upwardly with `the plunger len .. pump is secured..

\ pump. upper traveling valve and the upper standassembly. Therefore, during the up stroke of the pump the space in the lower barrel 1 2 between the lower working valve and the upper end thereof is decreased. The oil is therefore displaced and forced from the lower barrel 12 through the plunger tuber 65 into the upper end of the upper barrel 11 or into a pump tubing 120 to which the The upper plunger 61 moves upwardly with' the lower plunger and the entire column of oil above the upper plunger travelingr valve is moved upwardly therewith a distance commensurate with `the distance 'the plunger assembly is moved.

`Therefore, it will be seen that the amount of oil pumped from the upper end of the oil tube 120 will equal the sum of the amounts displaced by the upper plunger 61 and the lowerplunger 62. `Also duringl the up stroke of the plunger assembly the space between the lower standing valve and the lower traveling valve kis increased' and oil is drawn tliereinto from the exteriorof the Likewise the space between the ing valve is increased and oil is drawn into i this space `in the barrel from the exterior' of the pump. .During the up stroke yof the pump the upper and lower standing valves close. and therefore the oil drawn :into the lower ends of the upper and lower barrels is trapped therein. y The vupper and lower working valves, however, are opened during the down stroke and as the upper and lower plungers 61 and 62 lower, the oil will flow thereby to allow for the displacement.` On the down Astroke of the plunger assembly, a quantity of oil flows from the lower barrel 12 up the tube G5 equal to the space dis placed lby the additional length of the tube 65 which enters the lower'pump barrel 12 during the downward movement of the plunger assembly. This quantity of oil issuing from the cap 115 at the upper end kof the tube 65 during the down stroke of the plunger assembly does not cause an upward flow in the pump tubing 120 as it merely fills the space left in theupper end ofy the barrel,

11 by the sliding downwardly `of the tube 65 out of the barrel 11 into the plug 44.

lVhen it is desired or necessary to elevate the plunger assembly tothe surface of the ground for the purpose of inspection or repair, the plunger assembly is moved upwardly above its normal up position so that proliections 101 formed at the upper end of the lower plunger)` engage the projections 74 formed at the lower end of the plug 44. The whole plunger assembly is then rotated in a right hand direction by means `of the string of sucker rods.` and due to the fact that the threaded engagement of the plug 44 in the connector 1B is left-handed, it will be unscrcwed so that the plug 44 is free. The threaded engagement 45 is purposely made left-handed so that theplug 44may be unscrewed by a rotation of the stringy of sucker rods and the plunger assembly ,without` danger of unscrewing any of the other parts. lWhen the plug` isv completely freed, the whole plunger assembly may be velevated. from the barrel assembly to the surface of the ground. It is a very important` feature of the invention that this'plug maybe removed, since considerable labor and time is eliminated by not having to elevate the barrel assembly tothe surface of the ground whenever the plunger is elevated thereto.

y From the foregoing description it will be seen that myy invention provides a pump `having a capacity. which is `substantially twice the capacity ofthe ordinary Aoil well pump. It isfworthy of note that my pump although it has twice` thecapacitydoes not have any longer stroke than vthe ordinary pump, andl may therefore be] used with standard oil `well equipment which is a desired vadvantage over some special forms of pumps. rl`he pump of my invention is single acting and should not be confused with the double acting pumps which are entirely im practical for oil well use and have never been successfuh The pump of my invention is equivalent to two pumps buty the parts are so designed that the pump units thereof `cooperate so that they may be operated from a single string vof sucker rods. The feature of 'the removable plug is important and the means whereby the removable plug may be freed from the connector 153 is likewise important.` .y y i I claim as my invention: y

, 1. A pump for use in an oil well compris ing: an upper barrel having an upper bore;

an' upper plunger working in said bore; an upp'erworling valve so arranged as to per- Init yliquid to pass from the space below said plungerl into, the space above said plunger `but.'preventing-,a reverse movement of said liquid.; yan upper `staniiling valvearranged to admit liquid from the well into tlie space Abelow said upper plunger but preventing a reverse movement ol' saidliquid; a lower 410 barrely liaving a lower bore: a wall separating said upper borefrom said lower bore; a lower plunger workingin saidlowerbore; a lower standmg valve arranged to admit liquid fromytlie well into tlie space below 15 `said lower plunger but preventing a reverse Nmovementfoli said liquid; a lower working valve aranged to admit liquid from the space below said Ylower plunger to tliespace `above" said lower plunger but preventing a zfreverse imovement of @aid liquid; and a lioltubelipassing in -fluid-tight relationship through .said wall and connectingsaid upper Eand lowerplungers, said tube providing a tree.connection atall times vbetween the space labove said lower plunger and tlie space `above said upper plunger.

2. A pump for use in an oil Lwell comprisyzing: an, upperhbarrel having an upper bore; an upperJ plunger working in said bore; and

.30 upperqworking valve'carried by said upper plunger and so arrangedvas to pe "mit liquid to pass from the space below said plunger into the space above said plunger-,but preventing a reverse movement of said liquid;

l an upper standing valve arranged to admit liquid from the well into the space below said upper plunger but preventing a reverse Y movement of said liquid; av lower barrel having a lower bore; a wall lseparating said up- "perbore from said lower bore; a ,lower 'plunger 4working v.in said-lower bore; a lower standingvalve arranged to adinitliquid tromftbefwell into tbe space below said lower plunger but preventing Va reverse movei yment of said liquid; `a lowerV working valve ger and arrangedv ycarried ,by said lower plunL `to admit liquidfrom the space below said lower plunger to tbe space above said lower plunger Abut preventing a reverse movement 5() 'of said liquid: land a yHollow tune passing in fluid-'tight relationship through said `wall and connecting said upper and lower plungers` said tube vproviding a free connection at all times beliweentlle space above said lower 56 plunger and the space above` said kupper plunger.

3. A pump 'for use in Aan 'oil well comprising: an upper barrel having an upper bore; an upper plunger working insaid bore; an

60 upper working valve so arranged as to permit liquid to pass from the space belowy said plunger into the space above said plunger but preventing a reverse movement of said liquid; an upper standing valvearranged to @a `admit liquid from the well into the space below said upper plunger but preventing a reverse movement oisaid liquid; a lojwer barrel liaving alower bore which is of smaller diameter than said upperl bore; a wall Vsurrounding ,a spacev forming an opening which connects saidbores,a"port1on ef-the surface .of said opening forming a Y* supportingseat; a member resting in-luidtiglit relationship on said seat and thus closing said opening; a'lower plunger working in Isaid lower bore; a lower standing valve arranged to admit liquid'from tlie well into'thefspace below said` lower plunger butfpreventing a reverse movement ot said'liquid; a lower worlring valve arranged* to admit 'f'liquid from tliey space below said lower plunger to vtliespace above eaid lower plunger* bin; preplunger into thespace above said plunger but preventing a reverse movement of said liquid; an upper standing valve arranged to admit liquid from tlie well into thespace lbelow saidupper'plungerv but preventingla re- Averse movement of said liquid; a lower bar-l wrel having a lower bore ywlncli 1s of smaller diameter than said upper bore; a wall surrounding a space vforming an opening which `connects said bores, a portion of the surface of said opening forming a supporting seat; a member -resting in fluidtiglit relationship on said .seat and thusfclosing saidopening; a lower plunger working in saidA lower bore; al lower standing valve ,arranged Yto admit liquid'zfromthe wellrinto tlespace below saidlower plunger but preventing a reverse n'iovementjof said liquid; alow'er working valve arranged toA admitliqiiid from the space below said lower plunger to the space above said lower lplungerbutpreventing a reverse rmovement otsaidliquid; and a'plston rod yextending in fluidtightrelationship through said member and VConnecting said plungers, there being an open 4channel at all times between the `space directlj,7 above said lower piston and the space above said upper piston.

5. A pump for use in an oil wel] comprisinigzan upper'barrel having an upper bore; an upper plunger working inv said bore; an upper working valvesoarrang'ed ,as'to permitliquid to pass from tlc space below said plunger .finto the spfaceA `above said plunger but preventing' a 'reverse movement of sa'idpliquid; an `npper`standingvalve arranged to admit liquid from the well into lthe space below said upper plunger but preventing a` reverse movement of said liquid; a lower barrel having a lower bore which is of smaller diameter than said upper bore; a wall surrounding a space forming an opening which connects said bores; a portion of thev surface of said opening forming a sup-` porting seat; a member resting in i'luidtight relationship on said seat and thus closing said opening; means for mechanically securing'said member in luidtight relationship to said'seat; a lower plunger working in said lower bore; a lower standing valve arranged being at all times in open `communication with the space above said upper plunger.

6. A pump for use in an oil well comprising: an upper barrel having an upper bore; an upper plunger working in said bore; an upper working `valve so arranged as to permitliquid to 'pass from the space below said plunger into the space above said plunger but preventing a reverse movement oit said liquid; an upper standing valve arraiigedto admit liquid from the well into the space bei low said upper plunger but preventing a re verse movement of said liquid; a lower bar-v rel having a lower bore which is of vsmaller diameter thanvsaid upper bore; a wall surrounding a space forming an opening which connects said bores; a portion of the surface of said openingiorming a supporting seat;

a member resting in fluidtight relationship on said seat and thus closingv said opening; a screw thread on said member adapted to engage a screw thread in said opening for mechanically securing said member in luidtight relationship to said seat; a lower plunger working in said lower bore; a lower standing valve arrangedto admit liquid from the well into the space below said lower `plunger kbut preventing a reverse movement of said liquid;alower` working valve arranged to admit liquid from the space below said lowerplunger to the space above said lower plunger but preventing a reverse v movement of said liquid; and means for movingsaidplungers synchronously in the same direction in said bores, the space above said lower plunger being at all times in open communication `with the space above said upper plunger.

7. Apuinp for use in 'an oil well coiniprising: an upper barrel having an upper bore; an upper plungerworlring in said bore; an upper working valve so arranged as to permit liquid to pass from the space below said 4plunger into the space above said plunger-butpreventing a reverse movementv of said liquid; an upper standing valve ar` ranged to admit liquid from the well into the space belowsaid upper plunger but preventing a reverse movement of said liquid;

a lower barrel having a lower bore which is oi' smaller diameter than said upperbore; a wall surrounding a space forming an `opening which connects said bores, a portion of the surface ol said openingi'orming la supporting seat; a member resting in fluidtight relationship on said seat and thus clos ving said opening; means'for mechanically securing said member in liuidtight relationship to said seat, said means being so constructed that they can be disengaged by a rotation of said member inside said opening; a lower plunger working in said lower Y bore; a lower standing valve arranged to admit liquidi from the well into the space belowsaid lower plunger but preventing a reverse movement or said liquid; a lower working valve arranged to admit liquid from the space below said lower plunger to the space above said lower plunger but preventing a reverse movement .of said liquid;

and means for moving said plungers syn-H clironously in the saine direction in said bores, the space above saidl lower plunger being at all times in open communication with the space above said upper plunger.

8. A pump for use in an oil well' comprising: an upper barrel having an upper bore;

an upper plunger working in said bore; anv

upper working valve so arranged as to perplunger into the space above said plunger butpreventing a reverse movement ofsaid liquid; an upper standing valve arranged tov admit-liquid from the well into' the space below said upper plunger but preventing a reverse movement of said liquid; a lower barrel vhaving a lower bore which is of smaller diameter than said upper bore; a

ywall surrounding a space forming an opening which connects said bores, a portion of the surface of said opening 'forming a supporting seat; a member resting in luidtight `relationship on said seat and thus closing said opening; a screw thread on saidmem- `ber adapted to engage a screw thread in said opening for mechanically securing said member in liiidtight relationship to said seat; means being provided for turning said member in said opening by turningtheL ,sucker rods of the pump; a lower plunger working in said ,lower bore; a lower standing valve arranged to admit liquid from the well into the space below said lower plunger but preventing a reverse movement of said liquid; a lower working valve arranged to admit liquid from the space below said lower plunger to the space abovesaid lower l Utl `mit liquid to pass rfrom the space below said Cil plunger but preventing a reverse movement of said liquid; and means for moving said plungers synchronously in the same direction' inr said bores,` the space above said lower plunger being at all times in open coinmunication with the space above said upper plunger.

9. A pump for use in an oil well comprising: ari-upper bai-rel having an upper bore; anv upper plunger working in said bore; an upper'workingvalveso arranged as'to permit liquid to pass from the space below said plungeriii'totlie space abovelsaid plunger but prevent-ing a.'reversemovement of said liquid; an upper standing valve; a 'lowerbarrel havingla lower boiewvhich is of smaller diameterthan said; upper bore; a

wall surroundinga space `forming an opensv ingzwliiclifconnects'said boresya porti'on oi the surface of said open-ing forming ,f a sup? porting; seat; a member restingin fluidtiglit relationship on said` seat and thus closingV said opening-f; spaced-gpacking-rings dis#V posed-betweensaid member and said seat :tol

seal oii' a` spacetherebetween, there being :a f

passage connectingfsaid space'to the exterior of the' pump "and: anotherpassage con-y necting-.saidv space with saidupp'er standing valve; a'lower plunger working -in said-lower bore; a lower standing-valve arranged to admitcliquid; from the wellA into thel 4spacey below said lower plunger Vbut preventing a reverse'rmovemefnt of 4saidliquid;A a vlower working-.valve arranged togv admit`` liquid from; the -1 space; bel-ow said lower; plunger between said member and saidseat to sealed' to tlieaspaceabove said lowerplunge-rybut'l preventing; 'a' reverse movement of said 4liq;

uid :and means 4for movingaidi -plungeis synchronously inl the-same direction in said bores;thespace'above said -lower plunger' beingf' atky allv times vin op en communicationf witlrthe space above said? upper plunger.v

prising: ancupper Abarrel* having an v upper bore;-an upper plungerworkinglin said-l bore; Yan-'upper working valve 'so varranged astopermit liquid to'pass from the space below saidplunger into vthe space Yabove said plunger but preventing .-a reverse movementfof sa-id liquid; an .upper` standing.-

valve; a; lower barrel hafvingfa lower bore which lisiof sinalleridiameter than said Y upper 'bore ;`-a wall surrounding a space form'- ing :an-openi-ng-which connects said bores,

a'portionHof the surf-acefot said openingV incassa said memberand saidseat by a rotationy of .l

uid; and means ior moving.: said plungers synchronously in the same direction injsaid bores, the space above said lower plunger being 'at all times in open communication withthe space'abovesa'id upper plunger. v

ll. A pump for use in an oil well coniprising.: an upper barrel having-an upperE bore; lan upper-plunger working-in saidbore; anupper working valve so arrangedas to permit liquid'to pass from the space below p said plunger into the space above said plungery but preventing-a reverse movement of said liquidyan upper standing valve; a lower barrel' having a lower bore which is of smaller diameter than said yupper bore;

a wall surrounding a spaceiforming an`open- Y* ing-which"connectssaid bores, a portion of the surface oi saidopening formingfa supporting seat; a member restinginiiuidtight relationship on said seat and thus closingsaid opening; spaced packingrings disposed space therebetween,v 'there being a passage connecting said space tothe exterior of the,

pump and another passage connecting'said space with said'` upper; standing valve; v

threaded Ameans for compressing said pack;-

seat by -a rotation'of vsaid member; 'means beingxprovidedl nfor turning said memberl in g said openingbyturning ltlie sucker rods of4 the pump; a 'lowerplunger working in said lower bore; a 'lower standing-valve arranged to admitliquid' from thev well into the space below saidlower plunger but preventing-5a reverse movement of said liquid;v al lower' working valve arranged to admit liquid from the Ispace 'below said lower plunger lto lthespace above said lower plunger 'but pre'ventingareverse movement of said liquid; and means for movingfsaid plungers synchro#v Qing/rings between said member and Asaidnously in the same;direetionin-said; bores, Y

orniing'asupporting-seat; a member restingw` in*- i'lu-idtight relationship on said seat andf'tliusclosing said opening; spaced ber-and said seat toseal' oit a space there'- betfvveen,i there being@ :passageconnectingsaid plunger 'into the space above said plung said Lspace to the exterior of they pump and" er but preventing a 'reverse movement ofanotlfier passage connecting said :space with f said upper standingfvalve; lthreaded means for compressing said packing rings between the space above said lowerl plunger being g'at 'all times in open communicationwwith the',t

space above said upper plunger.`k

l2. A pumpifo'r use in `an "oil wellecomf prising: an upperbariel havingian upper bore; an upper plunger working in said bore; packing rings disposed lbetweeny said f mein-l an upper working valve iso arranged as; toA

permit liquid to pass from the spacebelow ias said liquid; anupper standingfvalve; a

lower barrel liavinga lower bore which is' of smaller diameterthan said upper bore;

isa

-opening which connects said bores, a portion of the surface oi' said opening Jforming a supporting seat; a member resting in 'fluid-` tight relationship on said seat and thus closing said opening; spaced packingrings of different diameter disposed between said. member and said seat to seal olil a space therebetweeny there being a passage connecting said space tothe exterior of the pump and another passage connecting said space with said upper standing valve; a lower plunger working in said lower' bore; a lower standing valve arranged to admit liquid from the well into the space below said lower plunger but preventing a reverse movement of said liquid; a lower working valve arranged to admit liquid from the space below said lower plunger to the space above said lower plunger but preventing a reverse movement of said liquid; and means 'for moving said plungers synchronously in the same direction in said bores, the space above said lower plunger being at all times in open communication with the space above said upper plunger.

13. A pump for use in an oil well coniprising: an upper barrel having au` upper bore; an upper plunger working in said bore; an upper working valve so arranged as to permitk liquid to pass from the space below said plunger into the space above said plunger but preventing a reverse movement of said liquid; an upper standing valve ar-y ranged to admit liquid from the well into the space below said upper plunger but preventing a reverse movement of said liquid;

a lower barrel having a lower bore which` is of smaller diameter than said upper bore; a wall surrounding a space forming an opening which connects said bores,` a portion of the surface oi said opening'forming a supporting seat; a member resting in iiuidtight relationship on `said seat and thus closing said opening; means vfor mechanically securing said member in tluidtight relationship to said seat, said means being so constructed that they can be disengaged by a rotation of said member inside -said opening; a lower plunger working vin said lower bore; a lower standing valve arranged to admit liquid from the well into the space below said lower plunger but preventing a reverse movement of said liquid; a lower working valve ar ranged to admit liquid from the space below said lower plunger to the space above said lower plunger but preventing a reverse movement ofsaid liquid; means for moving said plungers synchronously in the same di rection in said bores7 the space above said lower plunger being at all times in open communication with the space above said up per plunger; and interlocking means on said member and said lower plunger adapted to engage when said lower plunger approaches said member to permit said member to be disengaged from said opening by turning y the lower plunger through said moving means.

In testimony whereof, I have hereunto set my hand at Los Angeles, California7 this 24th day of March, 1926.

EDGAR W. rirrriinsoii.

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