US2137403A

US2137403A - Pump

Info

Publication number: US2137403A
Application number: US130063A
Authority: US
Inventors: Daniel W Hoferer
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-03-10
Filing date: 1937-03-10
Publication date: 1938-11-22
Anticipated expiration: 1955-11-22

Description

Nov. 22, 1938. D. vv. HOFRER PUMP Filed March 10, 1937 .Mmm m vw Nov. 22, 1938 D. W. HOFER ER PUMP 2 Sheets-Sheet 2 Filed March 10, 1937 m LW 9 U, 0/07240 L 3 4Q Patented Nov. 22, 1938Y UNITED STATES eATENTfoI-"Fica 2,137,403 y. l f i PUMP` Daniel W. Hoferer, LongBeach, Calif.

Application March 1o, 1937, seria1No..13o,o63

In; g

*This invention relates to pumps and relates more` particularly to Well pumps such as oil well pumps. A general object of this invention is to provide a practical, efficient well pump embodying novel and effective means for preventing or` reducing shock to the relatively movable parts.

In my co-pending application entitled Well pump, Serial No. 130,062, filed March 10, `19?7, I have described and claimed a free barrel well wt; pump embodying a free or movable barrel and two plungers extending into the barrel, one

plunger being stationary, the other plunger being movable. Stopparts are provided on the barrel and plungers to limitrelative movement between 15u them and to prevent disassociation of the pump parts when `the pump is run into and `removed from the well. It is desirable to cushion or eliminate theshock to the barrel and plungers and `the parts connected therewith when the stop 20l parts come into contact during operation of the pump. i I

` It is another object of this invention to provide a well pump of the free barrel type referred to above embodying cushioning means for material-l 25 ly reducing or eliminating the shock and jar that might otherwise result from the contact of the stop partsof the barrel and plungers.

Another object of this invention is `to provide a well pump of the character referred to in which the cushioning means are hydraulic, employing the liquid around the pump as the shock absorbing or movement resisting medium. I

Another object of this invention is toprovide a pump of the character referred to in which` the cushioning means are simple and sturdy, embodying a minimum number of parts and connections. Another object of this invention is toprovide a Well pump of the character referred to in,

. which the cushioning means may be easily modimiiied to suit various conditions of operation, the

tion will be fully understood from the following detailed description of a typical, preferreduform 50` and application of the invention, throughout which Vdescriptionreference is made to the accompanying drawings, in which: l

Fig. 1 is a longitudinal detailed sectional view of the lower portion of the pump provided by this invention illustrating the tubing and` the 15 claims. (orma-i731 barrel in cross section. Fig. 2 is a view similar to Fig. l showing the upper portion of the pump. Fig. 3 is an enlarged, longitudinal detailed seotional view of I a portion of the pump showing certain ofthe .plungerparts in elevation and illustrating the cushioning means at the upper portion of the pump. Fig. 4 is an enlarged fragmentary vertical sectional viewof the lower portion of the pump showing parts of the lower vplunger in elevation and illustrating the cushioning meansfof the lower portion of the pump. Fig. 5 is a transverse detailed sectional view taken as indicated by line 5--5 of Fig. 4. Fig. 6 is an enlarged fragmentary Vertical sectional view illustrating thevalve on the movable plunger. Fig. '7 is a fragmentary` vertical detailed sectional View illustrating the valve on the standing plunger, and Fig. 8 is a. diagrammatic longitudinal sectional view showing theplungers in elevation and illustrating the barrel and the movable plungerl at the lower ends of their strokes.

AThe well pump `provided by this invention includes, generally, a free barrel I0, a standing plunger I.I` entering the lower end of the barrel and carrying a valve I2, a working plunger I3 entering the upper .end of the barrel I and carryinga valve I4, cushioning means I for preventing shock to the barrel and plungers when certain parts of" the same move together to limit the relative movement and cushioning means Iii for preventing shock to the barrel I0 and plungers Il` and I3 when parts thereon move together to limit relative movement between the barrel and plungerSf. I l

The barrel I0 isv an elongate, tubular structureA or member. In the pump illustrated the barrel ID is of uniform diameter throughout its length-and is a simple tube of considerable length. The opposite ends of the barrel Ill are provided withfiittings or parts that I will term puller nuts Il.` The puller nuts I1 may be alike and-may be threaded into the ends Yof the barrel IIJ. If desired one of the pullernuts Il may be an integral part ofthe barrel I0. Therpuller nuts `Il are preferably shouldered to bear against the ends of the barrel I0 when threaded in place. The puller nuts Il on the ends of the barrel I0 serve as bearings or guides for the plungers II and I3 and perform other functions as will be hereinafter described.

The standing plunger II is the stationary chored in a well tubing T. The plunger II is an elongate tubular member extending into the lower endof the free barrel IU. In they construction ,member of the pump and is adapted to Vbe anillustrated the plunger II comprises a lower tube I8 extending through the lower puller nut I1 and an upper tube I 9 extending longitudinally in the barrel I 0. The two plunger tubes I8 and I9 may be connected by a coupling 20 threaded to their adjacent ends. The plunger tube I8 may pass through the lower puller nut II with suitable tolerance or clearance, as illustrated. 'I'his relationship between the tube I8 and the lower puller nut I1 will be more fully described in connection with the cushioning means |5and I6.

Anchor means is provided to releasably hold or anchor the standing plunger in the tubing T. In the particular case illustrated the. plunger tube I8 is provided with a nut part or enlargement 2| which is threaded on the upper end of an anchor mandrel 22. The enlargement 2|"on'the" lower end of the plunger tube I8 isy preferably integral with the tube. The anchor mandrel V22 extends into a shoe 23 secured to the lower erd of' the tubing 'I'.l The shoe 23. is provided with an intera rounds the mandrel 22'to cooperatewith the seat 26. `The sealing member 21 is clamped between a shoulder 28 and a threaded nut 29 on the mandrel 22. Themember Zlis shaped to tightly seal against the seat 26.., Withthe parts related as j illustrated in Fig. 4 the enlargement 2| of the plunger tube I8 clamps against the nut 29 to serve as a lock nut. Theishoe 23 and the mandrel 22 are tubular so that the lower end ofthe standing plunger I I is inA communication with the well. The anchor mandrel 22 releasably` held in the shoe 23,; aswdescribed above, serves to, rigidly support the standing plunger II in a vertical position.

' The plunger I I'Iisprovided with packing means, for sealing with the interior of theV barrel III.

In practice any suitableform. of packing means may be provided. In. 'the structure illustrated vertically spaced sets orseries of packing rings 30 are provided on the plunger tube I9 to have sealing engagement withthe inner wall yof the barrel IIE. lThe sets of packing rings v3|Iare spaced apart and are spaced from .the coupling 2U and the partsat the upper end ofthe plunger II .byspacing collars 3 I. It will be observed that under certain circumstances the lowerend of the lower puller nut Ilmay engage downwardly against the enlargement 2| on the tube` I8 to limit the downward travel of Vthe free barrel I0. VvThus the lower puller nut I1 and the enlargement 2| serve as stop parts to limit movement between the barrel IIl and the plunger Clutch means are preferably provided on the lower puller nut I land the enlargement 2| to connect the lower end of the barrel I0 with the plunger II and anchor mandrel 22 to hold the l notches. f

The valve I2r is the standing valve of the pump and in accordance with the broaderraspects of the invention maybe of any-suitable construction II. iny one direction.

and type and may be positioned on the standing plunger |I as found most practical. In the form of the invention illustrated the valve I2 is in the nature of a ball valve comprising a cage 36 secured to the upper end of the upper plunger member I9,a seat 3l in the cage 36 and a ball 38 for cooperating with the seat 3l. The cage 3E is perforated or ported to have communication with the interior of the barrel i8. A web 39: may be provided at the upper end of the cage to limit upward travel of the ball 38 in the cage. The ball 38 is adapted to seat downwardly against the seat 3l to control communication between the 'interior of the tubular standing plunger II and the interior of the free barrel IIl. The assembly of the spaced sets oil packing rings 35 and the spacing collars 3| may be clamped between the valve cage 36 `and the coupling 20 of the plunger II.

The plunger I3 is adapted to be operated by a sucker rod or pump rod 40 and is the reciprocatingplunger element of the pump. The plungerv I3 isA an elongate tubular member or assembly and .may include an upper tube 4| extending through the upper puller nut I 'I and a lower tube 42 vwithin'the barrel I0. The adjacent ends of the plunger tubes 4I and 42 may be connected by an, integral coupling 43. The upper end of the upper plunger tube 4I is connected with the lower end of the rod 49. The rod 4G may be solid or nontubular. In the arrangement illustrated a ported coupling 44 is threaded on the lower end of the rod 45 and a tubular member 45 is provided on the upper end ofthe tube 4I and is threaded into the coupling 44. The ported coupling 44 places the interior ofthe reciprocating plunger I3 in communication with the tubing T. The member 45 may be integral with the plunger tube 4I or may be threaded on the tube 4|,.as illustrated. It will be observed thatthe upper puller nut VI and the member 45 may cooperate to limit movement between the reciprocating plunger I3 and the barrel I0 and thus constitute stop parts on the plunger and barrel. Cooperating clutch parts are preferably provided on the member 45 and the upper puller nut I'I to connect the plunger I3 and the barrel I0 against rotation when it is desired to tighten the threaded joints of the pump rod 40. In the simple construction illustrated spaced clutch lugs 46 are provided on the member 45 and spaced notches 4`I are provided in the upper end of the upper puller nut IIfto receive the lugs 46 to connect the plunger I3 and the barrel I0 against relative turning. The plunger I3 is provided with packing means for slidably sealing with the interior of the barrel I0. In the construction illustrated this packing means includes two vertically spaced groups or sets of packing rings 48 on the plungerv tube 42 slidably engaging the interior of the barrel ,I Il.. The groups of rings 48 are spaced apart and are spaced from the cou- Y pling 43 and the Vvalve I4 on the inner end of the plunger I3 by spacing collars 49.

The valve I4 is the working valve and controls communication between the pump chamber in the barrel I0 and the tubing T. The valve I4 may be of any suitable type and may be located as found most desirable. Intheform of the invention illustrated the valve I4 is a simple ball type valve provided on the inner end of the plunger I3. The valve I4, illustrated in the drawings, includes a tubular cage 50 threaded on the lower end of the plunger tube 42. A tubular inlet fitting 5| is threaded on the lower end of the cage 50. A seat 52 is clamped between the upper end of. the. iitting 5I anda shoulder 53in.v the cage 50. .Thelball 54 is. operable to cooperatezwith.

the seat 52to govern. communication between the; interior of the barrel I and theinterior` ofthe reciprocating plunger `VI3. A pin `55 extends through the cage 56" to limit upward movement ofthe ba1l.54. The-.assembly of the spaced sets of packing rings 48 and the spacing'collars 49.

may be `clamped between the coupling 43 yand the valve cage 56. .1 l J One of the cushioningmeans` I5 -is provided .to reduce or eliminate shock to the pumpparts when upward movement between the. plunger I3- and I0 relative to thefplungerJI iswstopped.` The.

cushioning means I5 herev shown are hydraulic means, it being understood that thev invention may be carried outwith spring cushioning means, bumpers, or cushioning materiaL-etc. The hydrauliccushioning` means I5 are advantageous as they maybe incorporatedin the pump at little `expense,.may `be regulated or varied to adapt the pump for use under .various operating conditions and are very effective. The two cushioning means I5 are provided at or adjacent theopposite ends ofthe free barrel I0 andmay be `alike orvery similar.

In Fig. s of the drawings I have illustrated in detail the cushioning meansIE at the upper end of the barrel I0 `for reducing the rate of moves. ment between the barrel and the plunger I3 when the upward movement of the plunger relative to the barrel is about to be stopped andwhen the downward movement. of theyb'arrel relative to the plunger I3 is about to be stopped. The inner off the coupling 43 `are adapted to cooperate to.` limit `the upward `movement of `the plunger. I3

enc'l of the upper puller. nut IT and the upper end relative to thebarrel I0 and` to limit downward movement of the barrel onthe plunger I3. The hydraulic cushioning means I5 at the uppergend of the barrel I0. utilizes 'or includes the annular fluidspace 56 in thebarrel I6 between the opposing ends of the upper puller nut Il and the..4

coupling 43. The volume orY thecapacity ofthis fluid space 56 is, of course,.reduced when there is relative movement between 4the barrel I0 and the plunger I3 to cause theopposing ends of the puller nut `I'I and the` coupling 43 `to move toward one another. Themeans I5 utilizes the iiuid trapped in the space 56 to control the `rate of this relative movement and thus cushion the shock that would otherwise result from the contact between the inner end of the puller nut Il and the upper end of the coupling 43. i

The means l5 provides for the controlled escape of the trapped i'luid from the space 56. The tolerance or clearance between the plunger tube 4'I and the interior of the tubular puller nut I'I' may constitute a means of escape for the trapped fluid in the space 56' that is substantially constant or of uniform capacity throughout the operation of the cushioning means I5. Further, the clearance or working tolerance` between the periphery of thecoupling 43 and the interior of the barrel I0' may constitute another substantially constant path of escape for the iiuid trapped in the space 56. In accordance withthe invention the tolerance or clearance space between the interior of the tubular puller. nut I'I 'up and the plunger tube. 4I. may be .small or great depending upouithe` specific gravity of. the. li-luid4 handled and other factors.` For-similar reasons the tolerance, or. clearance between the.` periphery eration.

of the coupling 43 `and the interior. of the barrel I0 may bevariedttoxsuit the4 conditions of op--l The cushioning4 means; I5 .at the :upper vend lof A the barrel IIB furtherincludes controlled ports 51 for the escape .of the fluid trapped'rin the space 56. In theiorm oi?.` the 4invention illus-Y trated there are a multiplicity of -longitudinally spacedports 51 in the wall of` `thebarrel I ilnto communicate with the spacey56and to `bacon? trolled by a parton the plunger I3.Q The ports:

5l are shown arranged in circumferentially.

spaced rows extending longitudinally of-tlie .bar- V` rel II) to be controlled by the coupling 43 ,ofthe plunger I3. It will be apparent howpthe lengt-. V

tudinally spaced ports 51 are` successively cut; off" by thecoupling 43 when the coupling Itand the puller nut I 'I moveA toward one another` .The

ports l571 ofthe spaced vertical rows preferably occur .in different vertical planes to besucces-y sively closed or cut oi by the coupling 43. AFurther, it may begpreferred to design theymeans I5 sotthat the spacing and/or the areas of the ports.

5l provide.aprogressively increasing pressure in the space 56 and,` therefore, a progressively in;- creasing cushioning action. This may be, accomfplished by graduating' the diameter or capacity of the ports 5'! making theports :nearest -thepuller` nut |11 of the smallestv diameter and/ortbyjvary-f ing the spacingV of the ports.` The invention contemplates the making ofthe ports-5lI .of selected capacity to provide ffor the proper operation ofA the means `I5 under different operating conditions. 1g, r

From the above it will be seen, that thefcushinning means` I5 at-the upper end of the barrel.,

Ill provides a uniform capacity escape ci fluid from the" space 56 `through theclearance between the interiorof the upper puller nut I'I' andwthe plunger tube 4I, a similar constant capacity ese..` cape through the tolerance betweenthe` coupling i 43 andthe interior of the barrel` III, anda grad-- ually decreasing.escapel through the ports 5l. Alin this connection it is to bey understoodthatfthere may be a clearance space of any reasonablecaff pacity between'the coupling'43 and the interior` ci the barrel II) and thatthis space may be prof` videdby reducing the diameterfof the Aupperpor.-

tion of .the coupling. 43 or by reducing, the-exa termal diameter of the entire coupling.w..The uid .from the space 56 that escapeslbetween the coupling 43 and the wallfof the `barrel il] passesout through the ports 51. into the tubing 'I' and does not reach or pass-the packing 4i! oi' the plunger I3, C 5 A When the inner end of the upper puller nut I 'I and the upper end of the coupling 43 `approach one.. another either due to movement ci'. thev plunger I3 relative to the barrel III, or movement of the barrel Il) relative to the plunger I3, `or theL combined relativemovement of the plunger :andi

barrel, the space 56 is, of course, reduoedin ca-4 pacity and the fluid trapped `therein isputunden an increased .pressure and displaced. Theine crease in pressure on the fluidin the space-.516 is accompanied by increased resistance to relative the progressive; cutting oir of the ports 5'I- by the' coupling 43 and the upwardly diminishing fluid capacity of the ports 51 that remain open to the space 56. Thus the movement is gradually cushioned or retarded until the inner end of the nut 5:2 I1 and the upper end of the coupling 43 come into close proximity, at which time a maximum pressure exists in the space 56 due to the fact that all or practically all of the ports 51 are cut ofi' and the fluid in the space is obliged to rescape l` from the tolerance spaces between the nut I1 and the plunger tube 4| and the coupling 43 and the.

interior of the barrel III. This reduction of paths of escape for the fluid-from the space 56 results in the reduction of the rate of speed between the barrel I6 and the plunger |3 to a minimum when the opposing ends of the coupling 43 and the puller nut I1 move into engagement so that even though these parts do come into contact there will be little or no jar or shock to the pump parts. It is to be'particularly noted that the increase in pressure in the fluid space 56 to a maximum is not accompanied by the leakage of fluid past the packing rings l46 of the plunger I3. The tolerance or clearance between the coupling 43 and 261 the interior of the barrel I0 has communication with the ports 51 that are covered or cut olf by the coupling 43 so that the fluid escaping through this clearance space from the space 56 is free to escape from the ports 51 and does not continue SOFT past the packing on the plunger I3. v'The ports 51 maybe located so that they are all cut off from the'space 56 when the opposing ends of the coupling 43 and the upper puller nut I1 come into contact. The tolerance or clearance between the linterior of the nut I1 and the plunger tube 4| is such that the free barrel I0 may begin its downward movement relative to the plunger I3 with little resistance, there being a suflicient Vinlet of fluid to the space 56 and a minimum of friction between the tubing `4| and the nut I1.

The upper end of the lower puller nut I1 and the lower end of the coupling 20 may come into contact to limit the upward movement ofthe barrel lll'relative to the Vstariding'plunger |I and .the lower cushioning means I5 is provided to prevent; shock to the pump parts when this occurs. The cushioning means I5 at the lower end of the barrel I0 may be substantially identical with the means I5 at the upper end of the barrel 50; and which has just been described. The cushioning means I 5 at the lower end of the barrel I0 includes the space 56a in the barrel I0 between the lower end of the coupling 2U and the upper end of the lower puller nut I1 and vertically 55: spaced ports 51a in the wall of the barrel Ill communicating with the space 56a and controlled or cut off by the coupling when the puller nut I1 approaches the coupling 2I'I. The ports 51ab may be arranged in spaced vertical rows and 'may 00;. be graduated in diameter and spacing so that the ports of the smallest capacity and of the greatest spacing are at the lower ends of the rows of ports. The means I 5'at the lower end of the barrel I0 also utilizes the tolerance or clearance 65 between the interior'of theV lower puller nut I1 and the plunger tube I8 and the tolerance between the coupling!!! and the internal wall of the barrel I0 as substantially constant paths for the escape of fluid from the space 56a. These '10V tolerances or clearance spaces may have any selected or desired uid capacities toprovide for the desired escape of the trapped fluid from the space 56.V

The operation of the lower cushioning means uf I6 is the same asthat of the upper cushioning means I5 described above. When the barrel IIl approaches the upper end of its upward movement relative to the plunger II the upper end of the puller nut I1 moves toward the lower end of the coupling 20. The uid trapped in the space 56a resists the movement of the barrely IU relative to the plunger and this fluid is forced to escape from the relatively restricted ports 51a and the clearances between the interior of the puller nut I1 and the tube I8 and the coupling 20 and the interior of the barrel I0. Due to the fact that the ports 51a are graduated in diameter or spacing this resistance oiered by the fluid in the space 56a increases as the barrel I0 continues to move upwardly and when the upper end of the nut I1 is in close proximity to the lower end of the coupling 20 the fluid resistance is maximum with all of the ports 51a cut off and the fluid escaping only through the tolerances between the tube I8 and the nut I1 and between the coupling 20 and the interior of the barrel I0. Fluid escaping between the coupling 20 and the interior of the barrel I0 does not reach the packing rings but escapes from the ports 51a. The lower cushioning means l5 retards the upward movement of the barrel I0 as it approaches the upper'end of its stroke in such a manner that there is little or no shock to the pump parts when the upper end of the nut I1 strikes the lower end of the coupling 20. When the barrel I0 begins to move downwardly relative to the plunger II there is space for the ample admission of fluid to the space 56a to the tolerances in the nut i1 Y and about the coupling '20 to permit of the desired movement of the barrel. As the downward movement of the barrel continues the ports 51@ are successively uncovered to the space 56'L1 permitting an increased admission of fluid to the space.

One of the cushioning means I6 is provided to prevent shock to the pump parts when the member and the upper puller nut I1 come into cooperation to limit relative movement between the barrel II) and the plunger I3 and the other cushioning means I6 is provided to prevent shock to the pump parts when the lower pullernut I1 moves into cooperation with the enlargement 2| to limit downward movement of the barrel I0 relative to the standing plunger II.

Referring now to Fig. 4 of the drawings which illustrates the lower cushioning means I6 in detail it will be found that the said means includes n cooperable plunger and socket parts on the lower puller nut I1 and the enlargement 2|. In the particular form of the invention illustrated the lower end of the puller nut I1 has an annular socket 60 for receiving a plunger part 6I on the above described enlargement 2|, it being obvious that the location of the socket 6D and the part 6| may be reversed if desired. The socket 66 is open to the lower end of the nut I1. The puller nut I1 may be lengthened to provide for the formation of a socket 60 of the desired length. The plunger part 6| is a portion of reduced diameter on the upper end of the enlargement 2|. In the form of the invention illustrated the plunger part 6| is integral with the enlargement 2| and the tube I8. The upper corner of the plunger part 6| may be bevelled off. The plunger part 6| is proportioned to be received in the socket 60 when the barrel ID approaches the lower end of its downward movement. The socket 60 and the part 6| are cylindrical, it being understood that they may be tapered or conical, if desired.

ais-mos In vaccordance with the invention the part BI is related to the socket 5B to be received in the socket with tolerance or clearance. This clearance and the clearance between the interior of thelower nut Il and the plunger tubel con:

stitute the means or paths of escape for the uid trapped in the socket 6I). The clearance spaces between the periphery of the part 6I and the wall of the socket (ill and between the interior of the nut I'I andthe, tube I8 may have any selected uid capacities to assure the proper operation of the cushioning means I6` under the various conditions of ,pump operation.

When the barrel I approaches thelower end of` its downward stroke relative tothe standing plunger,` II` the nut I'I` may move downwardlyl over the part El, that is, the part ISI may be received in thesocketk 6B. The part 6I Y,of course trapsfluid in the socket 60 and thetrapped fluid having only limited means of escape from the socket offers resistance to downward movement ofthe bar-rel. The fluid trapped-in the socket 60 escapes through the tolerance space around the plunger part 6I and through the tolerance space inthe nut lII and these spaces may be proportioned sothat the pressure on the trapped liquid increases as the downward movement of the barrel continues. Thus when the upper wall of the socket 60 approaches the upper end of the plunger part 6I Ythe trapped fluid offers Vmaximum resistancegto movement of thebarrel I0 and retards the barrel movement to such an extent that there is little or no shock when'parts on the nut I'I contact parts on the enlargement 2|.

The cushioning means I6 at the upper end of thebarrel I0 for cushioning the engagement of the upper puller nut I 1 with themember 45 comprises cooperable socket and plunger parts on the said puller nut and part 45. In the case illustrated an annular socket 65 is provided in the upper end of the upper puller nut I'I to receive 'a plunger part 66 on the lower end of the memyber 45. The part 65 may be integral with the member 45 and may be a reduced lower end portion of the member. The part 66 and the socket 65 are of the same character as the corresponding socket and plunger elements of the cushioning means I6 described above. The part 65 and the socket 65 are proportioned to provide any selected clearance between them and, therefore, any selected rate of escape of trapped iiuid from the socket. Ina like manner there may be any suitable tolerance or clearance Ybetween the plunger tube 4I and the interior of the nutV I'I to permit the vdesired fluid escape from the socket 65.

The operation of the upper cushioning means IB is substantially `the same as that of the lower cushioning means.` When the member -45 on the plungery I3 approaches `the upper puller nut II the plunger part v615 enters `thesocket 65 to trapfluid therein which uid offers resistance to the movement. `The resistance offered by the fluid of course` depends upon the rate of its escape from the socket and due tothe very limited discharge capacity of the clearance spaces in the nut-Hand the socket 65 the fluid may offer appreciable resistance to movementso-ythat the member45 may be brought=into engagement with the nut; I'I with little orno jar to the pump parts. l C

In operation the pump rod 40 is -reciprocated in the usual manner to reciprocate the plunger I3secured to therod.` At the start of the down-A ward stroke of the plunger I3 the bar-rel III may be in ay position where its upper puller nut II is restingxonlor isadjacent the `-eouplinglll When the plunger -I3 moves downwardly it may move downwardly through the barrel IU which may tend toremain stationary or the barrel in vmay move downwardly together with the plunger. In practice it may be found that the `barrel IU moves downwardly with' theV plunger I3 butat an appreciably slo'werrate` than the plunger; The actionrof the-barrel Il) during this phase of operationggdepends-:upon various factors such as the pressurel conditions, the friction conditions and theaction vof the packingfrings 3U and 48. As the barrel-Ill and the plunger I3 move downwardly` the iuid` within the barrel |40 is displaced therefrom and forced upwardly through the valve; II4. and the plunger I3 to discharge into thetubing ,'I"` from the coupling 44. The valve 4lf2 remains `closed duringthe downward stroke. .Thef downward stroke may continue until the lower puller Vnut Il approaches the enlargement ,2|` at the lower end of the` plunger II at which time the plunger part 6I is received in the socket EU. Thefluid trapped in the socket 60 serves to' retard the downward movement of the barrel IIJ` sothat the lower puller nut I 'I does not jar against the enlargement 2|. It is believed that `the operation of the lower cushioning means I6 will be fully understood from the foregoing detailed description.

.At the startof the upward stroke of the plunger I3 the barrel IIl may tend to remain stationary, may move upwardly with the plunger at the same rate as the plunger I3, or may move upwardly with the Aplunger at a slower rate. During the upwardf stroke of the pump fluid is drawn into -thebarrel I0 through the plunger II and the valve` I2` and this action continues throughout the entire upward stroke. At some point during the upward travel of the plunger I.3,the.coupling 43 may approach the upper puller nutr I'I. When this occurs the upper cushioning means I5 4operates to accelerate the movement of the barrel I0 so that the pump parts are not subjected to shockor jar `even though the member 43 engages against the puller nut I'I. It is believed that the operation of the upper cushioning means I5 will be` understood from its foregoing detailed description.

The well pump provided by this invention em* bodies shock absorbing means or cushioning means that lprevent jar and shock when the stopv means or stops on the barrel and plungers come into engagement. They hydraulicI cushioning means I5 and `Il are extremely simple and may be inexpensively embodied in the pump structure. It will be observed that most of the elements of the hydraulic shock absorbing' means I5 and I5 do not in any way interfere with the normal functioning or operation of the pump andrdovnot embody any special moving parts that require regulation or adjustment.

Having described only a. typical preferred form and `application of my invention I do not wish to be limited or restricted to the specific details herein set forth, but wish to` reserve to myself any variations or modifications that may appear toy those skilledI in the art or fall within the-scope of the following claims,

Having described my invention, I claim:

1. A well pump including, two plungers, one a standing plunger, the lother a working plunger, a barrel surrounding and movable with respect to both plungers, valves in connection with the plungers, stop parts on the barrel and YWorking plunger for limiting relative movement between them, said'parts defining a chamber in the barrel, and means progressively restricting the discharge of fluid from said chamber as the parts move together to cushion the engagement of the said parts. Y

2. A well pump including, two plungers, one a standing plunger, the other a working plunger, a barrel surrounding and movable with respect to both plungers, valves in connection Awith the plungers, stop parts for limiting relative movement between the barrel and the working plunger, means for offering progressively increasing resistance to relative movement between the barrel and the working plunger as said parts move toward one another to cushion the movement limiting cooperation of said parts, s top parts for limiting relative movement betweenbarrel and the standing plunger, and means offering progressively increasing resistance to relative movement between the barrel and the standing plunger as the last mentioned stop parts move together to cushion the movement limiting-cooperation of the last mentioned stop parts.

3. A well pump including, two plungers, one a standing plunger, the other a working plunger, a barrel surrounding and movable with respect 4 to both plungers, valves in connection with the plungers, stop parts on the barrel and working plunger for hunting relative movement between. them, and ported dash pot means for cushioning the movement limiting cooperation of said parts.

4. A well pump including, two plungers, one a standing plunger, the other a working plunger, a barrel surrounding and movablewith respect to both plungers, valves in connection with the plungers, stop parts for limiting relative movement between the barrel and the working plunger, hydraulic means cushioning the movement limiting cooperation of said parts and offering progressively increasing resistance to movement between the barrel and'the working plunger as the said parts move together, stop parts for limiting relative movement between the barrel and the standing plunger, and hydraulic means for cushioning the movement limiting cooperation of the last mentioned stop parts.

5. A well pump including, two plungers, one a standing plunger, the other a working plunger, a, barrel surrounding and movable with respect to both plungers, valves in connection with the plungers, stop parts on the barrel and working plunger for limiting downward movement of the barrel relative to the working plunger, means associated with said parts for cushioning the cooperation of said parts, cooperable parts for limiting upward movement of the barrel relative to the standing plunger, and means for cushioning the cooperation of said cooperable parts.

6. In a well pump, a standing plunger, a. working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the working plunger operable to limit relative movement between the barrel and the working plunger, said parts and the barrel dening a, chamber, and means controlling the iiuid flow from said chamber whereby the fluid trapped in the chamber resists relative movement between the barrel and the working plunger.

7. -In a well pump, a standing plunger, a Working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the standing plunger cooperable to limit relative movement between the barrel and the standing plunger, there being a fluid chamber in the barrel defined by said parts, and means controlling the fluid discharge from said chamber whereby the fluid trapped therein resists movement of the barrel when the part on the barrel approaches the part on the standing plunger.

' 8. In a well pump, a standing plunger, a working plunger, a. barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the working plunger operable to limit relative movement between the barrel and the working plunger, there being a socket in one of said parts, and a piston on the other part adapted to enter the socket when said parts approach to resist relative movement between the barrel and the working plunger.

9. In a well pump, a standing plunger, a working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the working plunger operable to limit relative movement between the barrel and the working plunger, there being a socket in one of said parts, a piston on the other part adapted to enter the socket when said parts approach, and means controlling the fluid discharge from the socket.

10. In a well pump, a standing plunger, a working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the standing plunger cooperable to limit movement of the barrel relative to the standing plunger, there being a socket in one of said parts, and a piston on the other part adapted to enter said socket when the part on the barrel approaches the part on the standing plunger.

11. In a well pump, a standing plunger, a working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the working plunger operable to limit relative movement'between the barrel and the working plunger, said parts and the barrel defining a/ chamber, and means controlling the fluid flow from said chamber whereby the fluid trapped in the chamber resists relative movement between the barrel and the working plunger, there being longitudinally spaced ports in the barrel communicating with the said chamber, said means including a surface on the working plunger operable to successively cover said ports.

12. In a well" pump, a standing plunger, a working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the standing plunger cooperable to limit relative movement between the barrel and the standing plunger, there being a fluid chamber in the barrel defined by said parts. and means controlling the fluid discharge from said chamber whereby the fluid trapped therein resists movement 0f the barrel when the part on the barrel approaches the part on the standing plunger, said means including a surface on the standing plunger, the barrel having longitudinally spaced ports for communicating with said chamber and progressively covered by said surface when the part on the barrel approaches the part on the standing plunger.

13. In a well pump, a standing plunger, a working plunger, a barrel surrounding and movable with respect to both plungers, valves on the plungers, opposing parts on the barrel and the working plunger operable to limit relative movement between the barrel and the working plunger, said parts and the barrel defining a chamber, and means controlling the fluid flow t from said chamber whereby the fluid trapped in the chamberv resists relative movement between the barrel and the working plunger, there being longitudinally spaced ports'in the barrel of graduated fluid capacity communicating with the said chamber, said means including a surface on the working plunger Ioperable to successively cover said ports.

lll. In a well pump,l a standing plunger, a working plunger, a barrel surrounding and movable with respect to both plungers, Valves on the plungers, opposing parts on the barrell and the standing plunger cooperable to limit relative movement between the barrel and the standing plunger, there being a fluid chamber in the barrel defined by said parts, and

means controlling the fluid discharge from said chamber whereby the fluid trapped therein resists movement of the barrel when the part on the barrel approaches the part on the standing plunger, said means including a surface on the standing plunger, the barrel having longitudinally spaced ports of graduated iuid capacity for communicating with said chamber and progressively covered by said surface when Vthe part on the barrel approaches the part on the standing plunger.

i5. A well pump including, two plungers, one a standing plunger, the other a working plunger, a barrel surrounding and movable with respect to both plungers, valves in connection with the plungers, stop parts for limiting relative movement between the barrel and the standing plunger, and cooperable cylinder and plunger elements on the barrel and the standing plunger for cushioning the cooperation of said parts.

DANIEL W. HOFERER.