US 2711939 A
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June 28, 1955 T. B. LosEY ADJUSTABLE WELL swAB Filed March 14, 1949 3 Sheets-Sheet l Thomas B. Losey BY :c
TTURNE Y June 28, 1955 T. B. LosEY ADJUSTABLE WELL swAB 5 Sheets-Sheet 2 Filed March 14, 1949 67:67 60 JNVENTOR. /lomas' B. lossy BY v a M i ffl s iff l', In
n ATTORNEY June 28,1955 T. B. Los@ Y 2,111,939
Y ADJUSTABLE WELL swAB 3 Sheets-Sheet 3 Thomas B. L o s e y INVENTOR.
ATIURNEY United States Patent O ADJUSTABLE WELL swan Thomas l. Losey, Dallas, Tex., assigner to The Guiberson Corporation, Dallas, Tex., a corporation of Delaware Application March 14, 1949, Serial No. 81,239
l2 Claims. (Cl. 309-33) This invention has to do with well swabs employing reinforced flexible cups in which floating reinforcing elements project upwardly out of the cup wall, and in which the contraction and expansion of these elements may be regulated, both manually and automatically, to control the cup diameter.
This invention employs Well swabs which are adjustable within a predetermined range of various diameters of the flexible elements of the swab cupsA The range of such adjustment may be determined by the use of circular retaining members of different sizes and physical characteristics, including both elastic and non-elastic retainers. When the latter is used the outward expansion of the cup is more strictly controlled while the inward movement remains free of such control. When an elastic retainer is employed, both the outward and inward movements of the cup lip and llexi'ole walls are given wider ranges of accommodation, and both of said movements are freely accomplished, within certain predetermined limits.
The invention here oiered provides unique reinforcement to the cup by the use of free floating ribs which are not attached to any non-yielding members, thus allowing them a certain measure of self-adjustment in all directions.
This invention affords far greater strength in the cup than any heretofore known of comparable size and weight, by allowing an increase in the number of reinforcing ribs which may be accommodated within a cup of any given diameter; and at the same time the structure is actually increased in flexibility.
This invention `has the advantage of allowing the use of the maximum number f reinforcing ribs or wires possible, and at the same time providing a cup of light weight within small compass and of great strength. Notwithstanding all of this, my cup can be made more quickly and inexpensively than conventional swabs as heretofore known.
Swabs previously manufactured usually included a mandrel and a thimble and reinforcing wires (sometimes called skid elements, wickers reinforcing rails or the like), an-d such metal cup members were usually welded, brazed, locked or threaded into each other and/ or to some other metal parts of the cup assembly. Foriinstance, the reinforcing wires were frequently found locked or threaded into or irremovably attached by some means (and occasionally by welding or other processes of fusing metal) to a thimble or shoe or base collar or the equivalent, creating at once a rather rigid and inelastic structure. Frequently in the past the members named, or one or more of them, and especially the reinforcing wires have been attached to the mandrel which was ordinarily made of a metallic tube arranged within the cup body. Such arrangement compounds the inflexibility of the structure, increases its original cost and the expense of maintenance and makes structural parts irreplaceable, requiring the purchase of a complete new swab assembly, even when only one part thereof is worn or damaged.
Often old style swab cups provided reinforcing wires Patented June 28, 1955 ICC which were tied together by circular bands of steel arranged within the cup body and to which they were lrmly attached. This, too, resulted in rigidity, and made a non-adjustable structure, particularly at the region or plane where these members were ixedly attached or tied together. Further old style devices have been found to employ a holding crown or 'top tying member consisting of a plate or an inverted steel cup or a rigid ring with wire-receiving holes in it, or some other non-yielding reinforcing member to which and/ or in which the ends of reinforcing wires extending above the cup wall were fxedly or permanently attached. The strengthening and reinforcing members appear to" have been invariably confined in such a manner as to prevent their lateral movement in the region of such attachment.
In the usual forms of the old swabs, a steel skeleton was firmly kuit together and implanted in a rubber cup or built `around it like an iron cage. Scattered stiffness was achieved, and the capacity for adjustment under load and stress was destroyed or so badly crippled as to become negligible.
Therefore, we find all such structures incapable of suliicient adjustment, through either manual or auto'- matic means. Their range of usefulness was severely limited, and a great multiplicity of sizes was required to lit into pipes of various diameters, and even to t into pipes having the same external diameters but with varying wall thicknesses. Manufacturers, dealers and well operators were forced to keep a relatively great stock of cups, varying only slightly in sizes.
All of such excessive and undesirable structures, limited operations and tedious and expensive processes of manufacture fixed rigidity in reinforced swab cup construction have been entirely eliminated by this invention.
So that this invention may be better and more fully understood, I have provided the accompanying drawings of satisfactory and typical forms of structures employing it, in which:
Fig. l is a sectionalized elevational view of a typical adjustable multiple swab assembly, loaded and moving upwardly within a well pipe. I t
Fig. ll is a partially s'ectionalized lelevational vie'wdf a typical free floating and adjustableswab cup.
Fig.' lll. is a partially sectionalized view of an-unatached thimble for supporting the cup shownfin Figfs'll.
Fig. lV is a plan View seen from above of a'typicalcup in which the ribs are temporarily constricted to receive a retaining ring.
Fig. V is a plan view of the device shown in Fig-IV wherein the stays have moved back against a retaining ring, now lodged therearound.
Fig. Vl is a view of a deformed upper end of one ofthe ribs with a retaining ring holding it.
Fig. Vil is a sectionalized plan view of a rib embedded in the edge of the plastic composition wall of a cup.l
Fig. Vlll shows a form of expansiblev retainer ring m-ade in two parts.
Fig. TX shows a sectionalized perspective view of a one piece elastic retaining ring.
Fig, X shows a plan view of a split spring steel expansible retaining ring made in one piece.
Fig. Xl shows a partially sectionalized elongate form of a modified cup permitting maximum expansionra'nd employing coil spring retaining ring.
Fig. Xll shows a sectionalized elevational 4View of a valveless swab supported on a solid mandrel. n n
Fig. Xlll is a plan view taken along the line XIII- f- Xlll of Fig. XII.
Fig. XIV is a plan View taken along the line XIV- XIV of Fig. XIl. g
,y 4So` that `the purpose of this invention may be more clearly stated and better known, some of the more important objects thereof are set forth as follows:
(l) vAnradjustable well swab of maximum elastic range and provided with the maximum number of yieldable reinforcingmembers.`
l (2) Means for so retaining reinforcing members extending above the wall of a swab cup as to allow their free inward movement without hindrance from the retaining member. n
(3) Retaining means so arranged about the free ends of reinforcing ribs extending above the wall of a swab cup as to allow their lateral movement, both inwardly and outwardly, in response to both the diameters of tubes through which the cup is made to pass and the amounts of the loads carried by the cup.
, (4) A swab cup so reinforced that the reinforcing ribs are never attached to any non-elastic member.
(5) A reinforced swab cup in which the reinforcing members are permitted movements of accommodation in all directions, including thevertical.
(6) A swab cup in which the reinforcing members are not attached to any central core, nor to any rigid support ing structure. l
(7) The provision of a swab cup in which reinforcing ribs extend above the lip of the cup into a plane of lconfinement wherein their range of lateral expansion may be regulated and altered by the use of retaining rings of varif ous Sizes, which may be manually removed, replaced and substituted at the pleasure of the operator, the cup being thus rendered more practical for use in passing through pipes having varying internal diameters.
. (8) The confinement within Vpredetermined limits of the expansibility of the free ends of reinforcing ribs extending from a swab cup, such confinement being effected by the use of expansible retaining rings which may be metallic, or plastic or of rubber or other composition.
(9,) A Aswab cup which may have the wall thereof elongated and made relatively thin and reinforced by ribs which support, strengthen and protect the wall and lip of the cup, and at the same time be capable of elastic movement, expansion and contraction throughout their lengths, and each such rib being capable of such movcment independently of the other ribs.
(l0) A swab cup having reinforcing ribs therein which are attached solelyfto elastic material and which extend upwardly above the cup without being xedly secured in the region of extension.
(11) A swab assembly in which various members V may be freely replaced when worn or damaged and/or when other sizes thereof are required, the said members being arranged to include a base thimble, a centrally disposed mandrel, a spacing sleeve arranged around such mandrel and a rib-retaining band arranged externally of the free ends of reinforcing ribs extending above the swab cup.
(12) A swab cup in which reinforcing ribs are employed without the necessity of having them arranged in slots or grooves about the body of the cup and without having to thread the ribs into any aperture or caps, or attachment device.
(13) A swab assembly including a swab cup having reinforcing ribs extending thereabove and so arranged, with respect to a sleeve disposed within the ribs, that the lfree ends of such ribs are so limited in their inward movement that they may not be accidentally freed from the restraint imposed by an annular band arranged externally of such ends.
(14) An elastic cup having floating rib members and which can be inverted or made oversize and used as a packer or fluid holding cup generally (as well as being capable of use as a swab cup).
(15) A swab employing a cup having floating skeletal reinforcement of such controlled elastic responsiveness as to render unnecessary the use of a valve.
The various parts of the swab assembly have been indicated by numerals, like parts having the same numerals; and the numeral 10 indicates a well pipe or other tubular member, such as a casing, in which a swab can be lowered and through which it can be lifted to bring out a load of uid.
To facilitate the attachment of the swab assembly to some suitable rod or sinker bar for lifting the swab and lowering it (which rod or bar is shown as at 99) there may be provided the internally threaded coupling member 11, which is sometimes called a tool joint. A subconnector 12 may be and usually is employed between the coupling and the swab assembly arranged therebelow. (See Fig. I.)
The sub-connector may be provided with external threads 13 and 14 on its upper and lower ends respectively for making connection between the swab assembly and the rod or sinker bar. A valve housing 1S is provided with suitable internal threads to cooperate with threads 14. However, other suitable forms of attachment may be arranged as desired.
The valve housing 15 is provided with ports 16 therein, usually plural in number; and these may be arranged through the walls of the housing to allow the flow therethrough of uid, especially when the swab is being lowered into the hole to secure a load of fluid. Some type of valve is usually` arranged within this housing; and one of the most effective and satisfactory forms of valve structure would employ the valve ball 17, arranged on valve seat 18, so that the ball falls in place and closes the valve whenever a load of fluid is secured above the swab. This valve ball lifts, of course, as the swab descends into the well through the fluid. A swab embodying a modified form of my invention may be constructed and used without any valve.
A cylindrical mandrel, which may be a simple, straight, tubular member 20, is arranged immediately below the valve body and attached thereto, so as to communicate therewith; and such mandrel should be provided on its upper end with external threads 19 to cooperate with complementary threads arranged within the lower end of the valve body. External threads 21 may be provided on the lower end of the mandrel to secure the internally threaded member 25, which is a retaining nut arranged at the very base of the assembly. The bore or passage 22 arranged through the mandrel 20 is in free and open communication with the bore or passage 24 arranged within the retaining nut 25; and the latter is provided with inlet ports or openings 26.
A sleeve is provided, one form of which is the tubular member 27, arranged to slide over the mandrel 20 and t snugly therearound. The sleeve maintains the place- -V ment of the swab cups included in the assembly and also limits their inward contraction. At the same time the sleeve acts as a spacer member, fixing the distance between the cups. The sleeve 27 further coacts with the swab cup so as to seal against the passage of fluid around the mandrel and on either side of the sleeve itself,
employing in such coaction a resilient rubber-like annular cushion 36, which may be an independent gasket, or it may be made as a part 0f the swab cup body, and arranged on top of the bushing shoulder 34.
Another form of device for separation, spacing and supporting swab cups in the assembly is indicated as at 28, consisting of a heavy band-like member arranged immediately about the mandrel, to which it may be attached, if desired, by the use of threads, pins or other attaching devices. A spacing member may be arranged, of course, about the plain mandrel 20 or about and around any other tubular member used as a mandrel, or about a rod or other solid member, such as the cylindrical mandrel 90, passing through and/or beyond (above or below) a swab cup, as may be desired. Alternate forms of spacing members are shown in Figs. l, XI and XII.
afi-insee typical swab cup is shown as at 30. t is provided 'with a body portion 32, which may be made of rubber composition or other elastic plastic; and the lower part of such body is molded about the bushing 33, arranged in the base of the cup. This bushing strengthens and reinforces the cup and fixes the smallest diameter of the bore or passageway 39 arranged through the cup,
Bushing 33 is so constructed as to provide a shoulder 34 in the upper part thereof on which may be arranged the annular sealing cushion 36. A further upward extension of bushing 33 is provided in the form of the Ienlarged section 35 of its sidewall, embedded in the resilient composition material of the wall of the cup.
The lowermost part of the resilient cup body 32 is extended below the end of ioating rib 40 to provide a resilient base 37. Such arrangement allows the cup body to come to rest upon the upper face of supporting sheltl 49 of the base thimble 31.
Thus it will be seen that floating rib iii does not rest upon a metal base nor is it prevented from vertical movement whenever the cup wall 32 is put in stress. Even the upper part 35 of bushing 33 is anchored in the resilient cup body 32 in order that it may move upwardly or downwardly in conformity with elastic movement of the cup body itself. Such movement would be quite independent `of any movement of oating ribs 40.
It is of importance to note that the bushing 33 and the ifloating ribs 40 are not affixed to one another, nor are they attached to the thimble 31. There is in fact no rigid attachment whatsoever between these members, nor
is there any unyielding relation between them.
The thimble 31 is merely a supporting base. The
resilient cup body32 moves independently of it, and so does the floating rib 40, and likewise the bushing 33. 'This is true whether the' movement be lateral, oblique or vertical in any of these members.
Rib 40 is truly a floating rib, it being attached to no non-elastic member. Each isuch rib is independent of all other reinforcing ribs and of any other reinforcement. The bushing can be left out of the cup altogether, especially where the loads to be tcarried are relatively light.
Herein we nd the reason for quick, appropriate and independent response on the part of each reinforcing rib :to all stresses, whatever the direction thereof. The
Aresponsive accommodation of this cup is instant and accui f as will not actually contact the sides of the casing while it is being lowered therein (free of load). It will expand outward instantly as the load is caught, so that the load is then supported within the cup. The ribs 40 will move outwardly to furnish appropriate strong steel fingers or skids to allow the unobstructed movement of the cup along the sidewall of the casing and through and beyond couplings on the casing, notwithstanding the presence of open threads in the coupling or rough ends of the casing The rubber-like cup body is fully protected by these free iioating ribs, notwithstanding that they are so extremely self-accommodating in response to varying loads.
It is desired to make especially clear that the reinforcing ribs used in old style cups and customarily anchored at one or more places, need not be so anchored at all. In fact, repeated and constant experimentation and use of the instant invention has proved that the free Heating rib is a far more satisfactory form of reinforcement than any anchored reinforcement heretofore known. This is truly a resilient cup in every sense of the word. Its elastic limits have been materially increased by reason of the particular design and construction herein set forth.
Usually the uppermost part of the cup body is made into a thin wall section; and such a section is shown as at 38. This increases the elasticity of the cup and also increases its sustained carrying capacity. The thinned wall section provides a better reaction for catching and holding a seal around the lip and upper end of the cup body when it is hoisted upwardly. The lip section 38 may be merged into the thickest wall section of cup body 32 through the provision of the sloping wall section 38a, on the inner face of the cup.
The oating rib 40 should be arranged to continue downwardly and inwardly so as to provide a lower and inwardly disposed foot section 41; and the substantially vertically disposed midsection or skid section of rib 40 is shown as at 42. This rib continues further and extends upwardly above the body of the cup and beyond the cup wail in a free section of rib shown as at 43, and such free section is inwardly inclined. Near the uppermost end of rib 40 there should be provided a turn or twist or kink or bend, as at 44, in connection with which there is arranged an outwardly overhanding part 45 of the free section of the rib.
Within the region of the recess 44, and so that it may be held downwardly by the outwardly positioned tip 45 of the rib 40, there is arranged a retaining ring. The form of this retaining ring is not very important, but its function and its'relation to the ribs and to the sleeve within it is quite important. In anyevent, a retaining band is arranged externally of the free ends of the ribs. This band cooperates with the sleeve and/ or the mandrel in such way that it allows lateral movement in the ribs, but at the same time prevents free ends of the ribs from jumping out from behind such band. This is accomplished by arranging that the space between the innermost section of the deformity on the free ends of the ribs and the outer face of the sleeve or mandrel is less than the outward extent of the deformity on the uppermost'section of the floating rib. In short, after the swab is properly assembled, the ribs can never be free of the confining inuence of the retaining ring.
The employment of a simple flat annular retaining ring, such as the one shown as at 50, vastly simplifies the construction and the costs and the labor required in making and using it. No longer is there practiced any slow, laborious, hand-threading of wires into a multiplicity of holes punched through a top ring, as has been so prevalent in the past. No longer is there any fusion or brazing or weiding together of a top cap or plate or ring or band with the reinforcing members extending above the cup wall. All such costly, slow and tedious processes of manufacture have been eliminated altogether. This is done by the use of any form of non-attached ring, such as l employ, whether it be elastic or non-elastic.
There are no holes whatsoever in any retaining ring used. The ring can be slipped on and o of the free ends of the reinforcing ribs with the greatest of ease. If the size of any retainer ring used to limit the outward expansion of a particular cup is not the proper size for some job other than that on which the cup has already been used, then the operator has but to constrict the ribs below the level of the ring, slip it oif, and put on another one of the proper size, whether it be larger or smaller. This is one of the simplest operations possible. Likewise, sleeves of different diameters can be used as desired.
Even the sleeve can be eliminated in some uses of this invention; and a simple spacing nut with a depending cylinder can be arranged about the central tube or rod member of the swab to limit inward and/ or upward movement of the cup.
My new construction and arrangement of retaining means about the free ends of reinforcing ribs provide a further simplification which results in great economy. Where an upper ring or cap or top of a swab cup has been made under the old practices, and has become damaged or worn, it usually requires the entire rebuilding of the swab or the discarding of the entire swab cup. These matters were shop jobs, time consuming and costly. With my invention, replacement of worn parts can be made almost instantly on the job, where the production crew is at work. Nothing could be simpler than the replacement of a worn or damaged or bent retaining ring. It is difficult to see how any less expensive replacement operation could be arranged.
By appropriate exchange of retaining rings, it is possible to make a cup of any conventional diameter work perfectly in well tubing or pipe which would ordinarily require a different sized cup altogether. Manual adjustment through the provision or substitution of suitable sized retaining members about the ends of the reinforcing ribs makes any one of my cups operate over a wide range of sizes. Thus the supply of cups required to be on hand is greatly reduced, and the investment therein is lessened.
In the construction herein disclosed, providing for manual adjustment of the size and expansibility of swab cups by the use of different sized retaining rings, there is a certain automatic adjustment made by the cup itself, whatever the character of the retaining ring used and regardless of its size. If the ring be rigid, as that shown as at Si), then the free ends of the reinforcing ribs may not move outwardly beyond the contines of such ring. However, the inward movement of the ribs is limited only by the tubular member disposed through the ring. This member may be the mandrel or the sleeve, or any other suitable member as desired.
There is ordinarily practiced certain care in the selection of rings of various sizes and in the use of cooperating and related sleeves of various sizes and/or wall thicknesses. Either of these members, that is, the ring or the sleeve, may be interchanged to suit conditions on the job. However, the space between the inner face of the ring and the outer face of the sleeve should be such that any deformity arranged at the upper end of the reinforcing ribs would not be permitted to pass between these two members. Thus, the ribs may not bounce out of their limited annular area of lateral movement, and the retaining ring itself is-not accidentally dislodged from its position around the ribs.
Retaining members of expansible character may be used; and one such is shown as at 51, where a helical coil lspring is used to confine or retain the reinforcing ribs. It expands with changes in the load carried by the cup; and it alsoV expands further with respect to the size of the well pipe in which it is required to move under load, increasing in expansion as the pipe size increases. This is of tremendous value, especially when a string of well pipe has within it tubular members of varying internal diameters, as when some wall thicknesses are greater than others. A string of pipe may be of the same external diameter, but the walls of certain lengths of pipe therein may be very thick and others relatively thin. This well swab is self-accommodating to fit all the tubular members through which it is required to run, including the even larger pipe collars by which the several sections of the pipe string are held together. My swab simply breathes as it enters and emerges from confining tubes of varying diameters, meanwhile never losing its load of fluid.
An elastic retaining ring, such as ring l, and the others hereinafter discussed, always gently urges itself against the outer faces of the reinforcing ribs below the region of their deformity, so that there is never any tendency of such elastic or expansible rings to jump off of the rib cluster.
Another form of expansible retaining ring is shown in Fig. VIII, where it is indicated by the numeral 52. It is usually made of two parts. The outermost arcuate section of the ring 54 is usually channeled on its inner face to receive the innermost and flat arcuate section 53; and a stop 55 is provided on the inner face of member 54. This construction Yallows spring action in the retaining member, but it does not allow the innermost member to come loose or be disengaged from the outermost member thereof while in operation. This ring member is made so elastic as to permit the expansion of the assembly of reinforcing ribs and the cup on which they are carried.
An illustration of the normal expansion of a cup employing an elastic retaining ring is shown in Fix. XI, wherein inclined dotted lines show the shape and form of the expanded flexible cup and its reinforcing ribs, when the same is under load. The spring retaining ring 51 is expanded to a position shown as at 66; and the deformed ends of the reinforcing ribs have been thrust out laterally to a position shown as at 67; while the extreme outermost points of the ribs have been thrust against the inner face of the well pipe (represented by line 63) to la position shown as at 69. The travel of the cup lip, from its normal position when the cup is without load to its maximum position of expansion, is through the annular area shown as at 75.
In Fig. IX is shown a very satisfactory although inexpensive form of retaining ring 56. It is made of an endless rubber ring, such as rubber cord. It is simply expanded ysufficiently to be dropped over the deformed ends of the reinforcing ribs and fall thcrearound immediately below the deformities. It hugs these ribs closely, and will not become loose or be lost in operation. Nevertheless, it allows maximum expansion of the reinforcing ribs and of the cup wall, limited only by the confining walls of the well pipe through which the swab is required to operate.
Another form'of expansible retaining ring is shown in Fig. X, wherein a one-piece body is indicated as at S7; and this body is extended into two separate arcuate segments, 59 being the outside segment and 58 the inside segment, movable along their contacting faces whenever pressure requires the expansion of the ring. The ring is made of spring steel or other elastic material suitable for the purpose.
lt is to be noted that a preferred form of construction of my invention employs free floating ribs, of which both rib 40 and rib 60 are typical, and preferred construction requires that these ribs be not attached rigidly to any non-elastic member. In fact, their only attachment is to the very elastic cup wall or body.
The process of manufacturing my cup is made much less expensive by proceeding to set the reinforcing ribs in a jig for the molding thereto of the plastic material of the cup wall. This eliminates costly groove cleaning and drilling, and the threading of reinforcing wires into grooves and other openings in caps and bases and steel structures or rigid bases generally. None of that is used in my invention. I wish to point out, however, that the reinforcing rib is very tightly gripped by the rubber composition bonded to it, so that while the rib is never held rigidly, it is nevertheless held, even when the cup is under unusually severe stress and suffering severe clistortion from its normal form.
When conditions of unusual stress exist, and even when a normal load of fluid is carried in the cup, it is desirable that the reinforcing ribs be always so positioned that they also act as skids or slides or tracks or rails for allowing the easy movement of the cup body along the walls of even roughened surfaces. I make the cup to provide the rails to be set and adjusted in the extreme outer periphery of the cup wall. See Fig. VII. Note that the rubber overcovering on the extreme outer face of the reinforcing rib is practically non-existent, if it be there at all. This is shown as at 29, which is the plane of merger between the vertical outermost line of the reinforcing rib and the outermost wall of the composition of the cup.
While'my invention can be practiced by making a cup of rather short length, as shown in Fig. II, it is also practiced with great effect in elongated cups and those having very thin walls, as shown in Fig. XI. The very elastic and thin walled cup 7G readily expands outwardly to receive and lift a great load of uid, allowing the loaded cup to be guided upwardly in the well pipe by the oating reinforcing ribs 60 (which are constructed in substantially the same manner as the ribs in the shorter cup shown in Fig. ll, except that ribs are elongated). The inwardly inclined lower end of rib 60 is shown as at 6l, the midsection of this rib, which is normally in substantially vertical inclination` is shown as at 62; and the upper end of this rib is inclined inwardly as at 63. A bend or distortion is provided in the upper end of the rib 60; and such distortion may take any one of many forms. The simplest is shown as at 64, where the rib is simply bent outwardly to provide the outwardly projecting overhang of the extreme uppermost end 65.
The elongated cup is provided with a resilient or cushioned base 71, by the use of which the cup body may be caused to rest on the transverse base 46 of thimble 31 in such a position as to allow the cup to be supported, even when heavily loaded, without allowing the ribs 6i) to directly rest on such transverse base. Usually the side wall 47 of the thimble 31 is provided with a tapered inner wall. However, the shape of the upward turn of this supporting base is of little moment. It can be a cup-like structure, as shown, or it can be an annular ange with only a slightly upturned edge about its periphery. lt is provided with a central bore or passageway 48, through which may be passeda suitable mandrel, as mandrel 20. Although this mandrel is shown in Fig. I to accommodate only two swab cups in a complete swab assembly, very obviously' it can be made longer to support a greater num ber of cups; and a mandrel can be made shorter so that only one cup is carried thereon, as in Fig. XII.
The sleeve 27, which may be used with cup 70 shown in Fig. XI, is not passed entirely through the cup, but is caused to rest on the shelf 34 of the bushing 33, with resilient gasket material 36 provided therebetween. Such material affords a very effective seal to prevent the leakage of iluid carried in the cup, so that it will not pass downwardly through the passageway 48 or be otherwise lost.
in the elongated cup 7l) (Fig. XI) there may be provided, as at 72, the bushing-reinforced lower section of the resilient Wall; or the base of the cup wall may be reinforced through the use of reinforcing material of some other shape, design or nature. l usually provide a tubular bushing substantially like that shown as at 33. Further integration of such a member as a reinforcing device is left to the option of a manufacturer; but it is recommended that some projection from this tubular member be made inwardly of the body wall of the cup in its base section, the better to secure it and to strengthen the base of especially heavy-duty cups.
I recommend that the elongate and resilient midsection 73 of the wall of cup 7 il be reinforced only with floating ribs. This will insure that the thinner and upper part of the wall ofthe cup be the most expansible section 74, and that it be quite sensitive and responsive to uid loads picked up and lifted by the cup.
In Fig. Xll there is shown a further modication of a swab employing my invention. it is a valveless swab; and this embodiment is simpler and less expensive in manufacture, and in operation and maintenance, than the other forms disclosed in the drawings. It has the further advantage of being unusually free in movement when being lowered into a well (to pick up a load).
All forms of swabs employing my invention may be and should be used in such sizes with relation to the well pipe in which they operate as to fall freely therein and with a minimum of friction when being lowered. They operate faster and last longer if the maximum outside diameter of the swab cup is so sufficiently less than the 10 internal diameter of the well pipe that Contact between them is unnecessary. Friction is thus eliminated or minimized in the downward movement of the cup. Obviously such construction and operation will prevent any downswabbing effect. This is an important advantage.
In the modified form of cup disclosed in Fig. Xll it will be seen that I have provided an elongated elastic cup 8G, the body of which is made of resilient plastic material so as to provide a rubber-like cushion S1 below the ends of the floating reinforcing ribs 85. An inner lip 82, arranged within the cup near its bottom, will hug the solid mandrel 9i) and prevent leaks therearound when the cup is loaded.
The cup will quickly expand and take on a load of fluid when it is started upward in the well pipe. Thereupon the relatively thin Wall 84 of the cup will spread outwardly, including its thin upper lip 83, to engage the pipe wall in a sealing operation.
The extreme flexibility of the cup body, with its floating ribs, having loosely conned and unattached free ends 87, makes possible its completely satisfactory operation without a valve. The operation of lowering the semicollapsible cup into the well pipe below the fluid therein allows such fluid to ow freely around the cup until its descent is stopped and the cup begins its lift. The cup itself performs all the necessary functions of a valve. It spreads under load, seals against the well pipe 98, `adjusting itself instantly to variations in pipes and couplings as it passes through them, and thus trapping its load of fluid, lifts it.
The foot 86 of a typical floating rib 85 is observed to be attached only to the resilient base part of the swab cup 80. It is not attached to the supporting thimble 89. In fact, there is usually provided some Vspace between this foot section and the inclined inside wall of the thimble, so as to more generously accommodate the outward expansion of the rib when the cup is loaded. The cup actually rests on the cushion 8i of rubber-like material while it is being supported by the thimble 89.
Not only is the foot 36 of the rib bent inwardly, but; the free ends 87 of the ribs, at the top of the cup, arel themselves bent inwardly; and they are arranged to. terminate in some form of deformed upper ends, as at .y 33, sufficiently enlarged or turned outwardly or bent or formed in such fashion as to prevent the retaining ring from jumping off and around the deformities.
ln the swab shown in Fig. XII, it is to be noted that the mandrel rod 9i) is solid, and is provided with threads 91 on its lower end and with threads 94 on its upper end.
A retaining nut 92 is provided with internal threads and made up on the lower end of mandrel rod and immediately therebelow there should be provided locknut 93, to securely hold the retaining nut in place.
In the region of the uppermost ends of ribs S5 there l should be provided the internally threaded spacer meina suitable coupling member, which in itself may provide the measure of spacing between the cups in a plural swab cup assembly.
The other important function of the member 95 arises from the fact that it is provided with a depending cylindrical sleeve 96, which is normally carried in such position as to fall within the encircling cluster of the deformed ends S8 of the ribs 85. The outer diameter of' Obviously sleeve cylinders 96.,
11 ate needs of the work to be done, the size of the swab considered.
Whenever the spacer-sleeve member 95-96 has been made up to the required position, then the loclrnut 97 should be run down firmly against it, to secure such cornbination member against unwanted movement. When locked in place, the member 95 should be positioned at such a height that there is a definite space below its under face and above the deformed ends 38 of the ribs. This space is provided so that the swab cup is free to move, to a veryl limited extent, longitudinally on the mandrel 90. The cup is longest when unloaded and shortest when carrying a full load. The member 95 should not at any time touch the deformities 80, thus preventing friction therebetween and allowing a fuller measure of expansion and movement in the cup.
Around the uppermost parts of the free ends 87 olf the floating ribs of the cup should be disposed any retaining ring which particularly tits the needs of the work required to be done. In the drawing of Fig. XII there has been shown a continuous one-piece rubber-like retaining ring S6. However, such ring could be replaced with any of the rings shown, such as Si), l, 52 or 5'7.
A standard rod coupling il may be used to fasten the mandrel 90 to the sinker bar 99.
I have presented the invention of a very elastic and easily self-adjusting swab cup and swab assembly. The swab may carry a number of cups and be arranged in various modifications. The cups themselves may be modified to suit the needs of various kinds of swabbing work or uid retaining operations. Substantially, they are all provided with free floating ribs having free ends with deformed termini; and around these free ends is arranged a suitable retaining ring, which may be rigid or elastic, as desired. There is no fixed attachment whatever between the ribs and the ring. The ribs are never attached to anything which is not elastic. The cup base is provided with a resilient cushion.
My invention may be employed with cups assembled in a swab carrying a valve; and likewise it may be practiced in a valveless swab assembly.
Automatic adjustment of the cup inwardly is always possible; and the outward movement of the cup is further regulated and conditioned by the character of the retaining ring used about the ribs. A cup is made to have a wider range of usefulness by reason of the selection of suitable retaining rings, with the result that a cup of any given size may be made to do the work of conventional cups of several different sizes.
Through a bore arranged in the base of the cup there may be provided a hollow mandrel or a solid mandrel, depending on whether or not a conventional valve is to be used in the swab.
My invention presents a swabbing and fluid-retaining or packing device of extreme flexibility, having a wide range of usefulness, longer life, greater economy in manufacture, operation and maintenance, a minimum of friction, and unusual capacity for self-adjustment, entirely free of the conventional fixedness and costly rigidity found in ordinary swabs.
Having presented it, I desire to claim my invention broadly, representing that it may be practiced in devices having many forms, intending that I be not limited to those set forth herein.
l. ln a well swab, a yieldable swab cup; reinforcing ribs carried by the yieldable material forming the cup wall, the ribs being provided with free ends extending above the wall; a floating retaining ring carried solely bysaid ribs and being so arranged about said free ends thereof as to control their outward movement; and a tubular member so arranged within said ring as to limit their inward movement.
2. In a well swab, a resilient plastic swab cup; reinforcing ribs attached only to the resilient material ot' the cup and provided with free ends extending thereabove, a floating retaining ring carried solely by said ribs and being so arranged about said free ends as to control their outward movement, and a cylindrical member so disposed within said ring as to limit the inward movement of said ribs.
3. in a well swab, a swab cup having an elastic wall and provided with a passageway therethrough; a bushing arranged within said cup and about said passageway. the bushing being provided with a shoulder therenn; resilient material arranged on said shoulder; a tubular spacer member resting in said material and supported by said` shoulder so as to extend thereabove; reinforcing ribs carried by said wall and extending thereabove and terminating in deformed ends; a retaining ring so arranged about said rib extensions as to limit their lateral movement outwardly; and the tubular member being so disposed within said ring as to limit the inward movement of said ribs and prevent the passage of the deformed ends between such member and such ring.
4. .in a swab cup, a resilient body; reinforcing ribs carried by said body and so extending thereabove as to provide free ends; and a floating retaining ring carried solely by said ribs and being so arranged about said rib ends as to impose restraint only on the outward movement thereof and to allow the inward movement thereof free of restraint.
5. In a swab cup, a resilient body wall; reinforcing ribs secured in, said wall and provided with free ends extending thereabove; an expansible retaining ring so arranged about said free ends as to impose restraint upon their movement outwardly.
6. in a fluid holding device, an elastic cup; reinforcing ribs carried by said cup by being bonded therein, said ribs having free ends extending beyond the lip of the cup; an annular member arranged exteriorly about such free ends for controlling their outward movement only; a solid mandrel extending through said cup; and the cup being provided with resilient sealing means so arranged with respect to said mandrel as to prevent the passage of uid through the cup and about the mandrel.
'l'. In a fluid holding device, an elastic cup; reinforcing ribs carried by said cup by being bonded therein, said ribs having free ends extending beyond the lip of the cup; an annular member arranged exteriorly about such free ends for controlling their outward movement only; a cylindrical member so arranged within such annular member as to limit movement of said free ends; a solid mandrel extending through said cup; and the cup being provided with resilient sealing means so arranged with respect to said mandrel as to prevent the passage of fluid through the cup and about the mandrel.
8. In a well swab, a yieldable swab cup; reinforcing ribs carried by the yieldable material forming the cup wall, the ribs being provided with free ends extending above the wall; a oating retaining ring carried solely by said ribs and being so arranged about said free ends thereof as to control their outward movement; a mandrel extending through the swab cup; and a tubular member arranged about said mandrel and arranged within said ring so as to limit the inward movement of said ribs.
9. In a well swab, a resilient plastic swab cup; reinforcing ribs attached only to the resilient material of the cup and provided with free ends extending thereabove; a floating retaining ring carried solely by said ribs and being so arranged about said free ends as to control their outward movements; a mandrel extending through said swab cup; and a cylindrical member carried by said mandrel within said ring so as to limit the inward movement of said ribs.
l0. In a well swab, a swab cup having an elastic wall and provided with a passageway therethrough; a bushing arranged within said cup and about said passageway, the bushing being provided with a shoulder thereon; resilient material arranged on said shoulder; a mandrel extending through said bushing; a tubular member arranged about said mandrel and within said material with the lower end thereof supported by said shoulder so as to extend thereabove; reinforcing ribs carried by said wall and extending thereabove and terminating in deformed ends; a retaining ring so arranged about said rib extensions so as to limit their lateral movement outwardly; and the tubular member being so disposed within said ring as to limit the inward movement of said ribs and prevent the passage of the deformed ends between such member and such ring.
1l. In a swab cup assembly, a resilient cup body; a thimble arranged to support said body; oating reinforcing ribs carried in the wall of said body by being bonded therein and extending thereabove and also extending downwardly to a point near the base thereof, said upward extensions of the ribs terminating in deformed ends; the base of said wall being so constructed as to provide an elastic cushion between the lower ends of the ribs and the supporting thimble; a retaining ring arranged exteriorly about said ribs below said deformed ends; and a tubular spacer member carried by the cup body and extending upwardly through the retaining ring so as to limit the inward movement of the ribs.
12. In a swab cup assembly, a resilient cup body;
a thimble arranged to support said body; floating reinforcing ribs carried in the wall of said body by being bonded therein and extending thereabove and also extending downwardly to a point near the base thereof, said upward extensions of the ribs terminating in deformed ends; the base of said wall being so constructed as to provide an elastic cushion between the lower ends of the ribs and the supporting thimble; a retaining ring arranged exteriorly about said ribs below said deformed ends; a mandrel extending through the cup body; and a tubular member resting in said cup body and arranged about said mandrel and extending upwardly through said retaining ring so as to limit the inward movement of said ring.
References Cited in the ile of this patent UNITED STATES PATENTS 1,596,353 Hartman Aug. 17, 1926 1,793,644 Segelhorst et al. Feb. 24, 1931 2,144,997 Thaheld Jan. 24, 1939 2,305,282 Taylor, Jr. et al. Dec. 15, 1942 2,325,556 Taylor et al. July 27, 1943 2,336,090 Granger Dec. 7, 1943 2,480,830 Bell Sept. 6, 1949