US2656890A - Adjustable belly spring - Google Patents

Description

Oct. 27, 1953 A. H. BRANDON ADJUSTABLE BELLY SPRINGv 2 Sheets-Sheet l Filed Aug. 2, 1951 HE 7-770@ H @RHA/00N Oct. 27, 1953 A. H. BRANDON ADJUSTABLE BELLY SPRING 2 Sheets-Sheet 2 Filed Aug. 2, 1951 illllllll! lllllllil lil!!! n In' M 0 N m H. W W A WMW/ /QTT'OP/VEPS.

Patented Oct. 27, 1953 UNITED STATES PATENT OFFICEi .ADJUSTABLE BELLY :SPRING Arthur lH..Brandon, Long Beach, Calif. Application Augustfz, 1951,=SexiaLNo.-239,9f12

v8 Claims.

This .invention relates to an adjustable belly spring primarily designed for use in pipe in wells.

A primary object of the invention is to` provide an improved vbelly spring assembly wherein the belly springs may be individually adjusted to resist inward forces l'applied thereto equally.

Explanatory of the present invention there are a number of tools designed to be lowered .into a tubing `or casing wherein it is desired that the tool be accurately `'centered with relation to the tubing `or casing. One of such tools is `disclosed in my copending application for a Tubing Tester, Serial No. 42,055, vfiled August 2, 11948, now YPatent No. 2,630,632, wherein a type of inter-nal pipe caliper "is lowered into a tubing and has 'a plurality of outwardly urged lingers which when released press outwardly against the interior of the tubing. If the tubing is worn at la particular locality, lingers opposite the `worn portion of the tubing can spring outwardly to a greater extent than other 1in-gers, -or when the tool is disposed opposite an unworn locality. The degree to'which the lingers extend outwardly is electrically transmitted to the surface and in this manner the places where 'the tubing has become severely worn and should be replaced vis ascertained.

In order to secure accurate information with a tool of this character it is of 'the utmost iinportance that the tool be held `centr-ally of the tubing that is being cali-pered for if the tool is displaced from the axis of the tubing some fingers will be abnormally depressed and other nngers will be permitted to expand outwardly to anV excessive degree, indicating that the tubing is worn whereas, 'as a matter of fact, it is not.

Belly springs have heretofore been employed above and below the tubing tester for centralizing the tool with relation to the tubing, but it is found that in the usual or conventional bellow spring assembly some of the belly springs will be stiier than others. This may be due to a variety of different reasons, such as 'unequal thickness ofthe belly springs or an uneven temper ofthe individual springs. Consequently, in the usual belly spring assembly one or more of the belly springs may be stilier than others with the result that the belly spring assembly 'Willrnot centralize itself within the tubing, and consequently the tubing tester will be displaced -by the belly springs from the axis of the tubing. In tools of this 4character wherein Very small lmeasurements are made and transmitted to the surface, it is of the utmost importance that the tool be held by the belly springs as close to a coaxial position with respect to 'the axis of the tubing 2 as possible, By means of the present invention, although the individual belly springs making up a belly spring assembly may be -of unequal stiff-- ness they may be individually adjusted so that all springs will press outwardly with equal force. Consequently, when the .belly spring assembly 'is lowered into -a tubing land the belly springs are pressed inwardly thereby, each of the individual belly springs Will resist the inward pressure with an equal force. In this manner ythe belly spring assemblies can be caused to `accurately center themselves with relation te the` tubing and will gold `the tubing tester `in a truly coaxial ,posi- Another object of the invention is vto provide an improved belly spring 4assembly wherein the belly springs may be releasably held in 'contracted positions while the assembly is `being lowered 4into a Well 'or downwardly through the` tubing and` then released and allowed to expand into engagement with the interior of the well or the tubing creasing as thecase may be.

Heretofore belly spring assemblies have been lowered into the well while in their fully expanded` positions and, although the belly springs may be equipped- With wearor abra-sipn-resistant pads., these pads Ymay haveunequal hardness or vmay have unequal abilities to` resist abrasion. During the descent of the assembly into the well the fpadson the belly springs, if the. belly springs are so equipped, are unnecessarily 'subjected to wear and if the wear is unequal the assembly may be incapable `of Icentralizing `itself withinthe well lor tubing with absolute accuracy. By `holding the belly `springs in 'contracted positions while the assembly is being lowered into the well, such unnecessary Wear is completely 'eli-minated and when the springs are ultimately vreleased and are allowed to expand there is a greater opportunity of absolute centralization being secured. This has a 'greater opportunity of being maintained fas the assembly is drawn from the well due to` the fact Athat the pads or belly springs have not been subjected to wear during the descent.

With the foregoing and other objects in View, which will be made manifest in the following detailed `description 'and specifically pointed out in the appended claims, reference is had to 'the accompanying drawings for-an .illustrative em bodiment fof the invention, wherein:

Figure 1 vis a sectional view through a tubing illustrating a tubing vtester 'disposed vtherein and held in centered position by belly spring assemblies embodying the present invention;

Fig. 2 is a vertical section through one of the belly spring assemblies;

Fig. 3 is a horizontal section taken substantially upon the line 3-3 upon Fig. 2;

Fig. 4 is a vertical section through an alternative form of construction illustrating the belly springs as releasably held in contracted positions;

Fig. 5 is a view similar to Fig. 4 but illustrating the belly springs as having been released and permitted to expand; and

Fig. 6 is a horizontal section taken substantially upon the line 6-6 upon Fig. fi.

Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout, I have illustrated in Fig. l a type of tubing tester disclosed in my copending application wherein a plurality of pivoted fingers I are urged outwardly by springs,

not shown, to engage the interior of the tubing 'I'. 'I'hese lingers have their lower ends held in contracted position by means of a slidable collar Il carrying friction springs I2 that are also engageable with the interior of the tubing as the tester is lowered therein. When it is desired to release the fingers I 0 the tool is pulled upwardly causing the friction springs I2 to draw the collar II downwardly, thus releasing the fingers I for outward swinging movement into engagement with the interior of the tubing. As the tool is drawn upwardly through the tubing, if one or more fingers encounter a worn spot therein these fingers may expand outwardly into the worn spot and the excessive expansion is electrically transmitted to the surface.

It will be understood that although the invention has been developed for use in conjunction with a tubing tester of this character it is not necessairly restricted thereto. The tubing tester shown is utilized for illustrative purposes only and the belly spring herein disclosed may be used on any tool to be used within pipe wherein it is desired to accurately center the tool with respect to the axis of the pipe.

The belly spring assembly embodying the present invention consists of a sleeve I3 which is externally reduced in diameter between its ends to provide spaced supports I4 and I5 for the belly springs. Around the sleeve there are disposed the individual belly springs I6. These springs may be anchored at one end to one of the supports, such as by screws Il and I8 and serve to span the distance to the other support. At the other support the springs are preferably slotted or bifurcated as indicated at I9 and screws extend into the slots. Adjacent the center of each outer spring I6 there is a pad 2I of hard wear-resisting metal such as for example tungsten carbide or the equivalent. These pads may be secured to their respective springs, such as by rivets 22. The pads 2i are designed to resist wear as the belly spring assembly is lowered through a tubing and is withdrawn'therethrough. In some instances the pads 2l may be dispensed with.

Overlying each outer belly spring I6 there is a second or inner spring 23. 'I'hese springs may have one end thereof anchored in place on the support I4 by the same screws I1 and I8 that anchor the corresponding ends of the outer springs I6 to that support. The opposite end of each of the inner springs 23 may merely rest against an annular shoulder' 24 formed on the support I5 so that the inner springs throughout the major portion of their lengths are slightly spaced from the outer springs I6. Adjacent the centers of the outer springs I6 there are adjustment screws 25. These screws extend through apertures in the pads 2l when these pads are employed and are threaded through holes in the centers of the outer springs. Their heads are preferably exposed through the outer ends of the apertures in the pads ZI to permit the application of a wrench to rotationally adjust the screws. Leaf springs 26 are secured to the under or inner sides of the outer springs IB and are biased inwardly. These springs have apertures therein through which the screws 25 extend and due to the bias of the leaf springs they tend to bind on the screws 25. The springs 25 function somewhat in the nature of locknuts or jam nuts effective on the screws to hold the screws 25 in any position to which they are adjusted.

`In the usual belly spring assembly there are four outer springs I6 distributed equally about the sleeves I3 although the invention is in no way restricted to this number'. ber of springs more than three may be employed. After the sleeve and the inner and outer springs have been assembled together each outer spring is tested to determine what external force ap-v plied to the pad 2i will deflect the spring I6 inwardly a given amount. If the springs are not of equal strength the screws 25 are adjusted. Thus, if a given spring It is a relatively weak spring the screws 25 are adjusted toward the underlying spring 23 so that the spring 23 is caused to cooperate with or assist in pressing the spring I6 outwardly. By adjusting the screws 25 on the various springs the underlying springs may be caused to cooperate therewith in such a manner that all springs will resist inwardly directed forces applied to their respective pads in equal amounts. Consequently, when the adjustment has been completed and the belly spring assemblies are introduced into the tubing T, the resistance to contraction of the complete assembly is equal on all sides of the sleeve I3. In this manner the tubing tester can be accurately held in a position coaxially with respect to the tubing. If the pads 2I become worn, small amounts of wear can be compensated for by adjustment of the screws 25.

In Figs. 4, 5 and 6 an alternative form of construction is disclosed wherein the belly springs may be releasably held in contracted position while the assembly is being lowered into the well.

' In this form of construction there is a central tubular supporting structure or sleeve 30 which is reduced intermediate its ends to provide external integral shoulders 3l and 32. The belly springs 33 are illustrated as mounted on the upper shoulder by lmeans of screws 34 and have bifurcated lower ends that slidably engage screws 35 on the lower shoulder 32. The belly springs are equipped with external wear-resistant or abrasion-resistant pads 33. The assisting springs 31 that are disposed beneath or inwardly of each belly spring are attached to the upper shoulder 3l by the screws 34. These springs terminate slightly below the screws 38 which are threaded through the pads and through the belly springs 33. These screws can be rotated by means of a socket wrench or the equivalent to adjust or vary the pressure exerted by the assistant springs 3l urging the belly springs 33 outwardly. By means of this adjustment all belly springs may be adjusted to press outwardly with the same or equal force as previously explained. In this form of construction each of the belly springs 33 has se- .cured thereto a iinger 39 that-extends downwardly Three or any numnimma in spaced relation to its interior-surfaceso asl to be engageable. by` an upwardlyextending ange 40 on a slidable collar 4l that is slidable on the sleeve or supporting structure- 3U. The collar 4l equipped with spring fingers 42A which extend radially from the collar between the belly springs as shown in Fig. 6; These lingers. are depicted in phantom lines in Figs. 4 and" 5f due to their ar.- rangement between the belly springs. The wire ingers 42, are adapted to engage the interior of a tubing o-r the Walls of a wellV or Well-casing and when so engaged they resist upward movements of the collar 4I when the assembly is pulled upwardly. The fingers 42, however, are not very strong and can be bent or broken off when the entire assembly is pulled up in the Well.

In this form of construction the belly springs and their assistant springs 31, although biased so as to be urged outwardly, are forcibly contracted prior to the introduction of the assembly into a tubing or casing. The collar 4I is slid upwardly so that its flange 40 may engage the ngers 49 and thus releasably hold the belly springs in contracted position. The assembly can then be lowered into the well and as the belly springs are held contracted the pads 36 are not subjected to any wear or abrasion whatsoever. When the assembly has been lowered to the required or desired depth it is then pulled upwardly. The spring fingers 42 tend to hold the'collar 4| stationary so that the ngers 39 can be drawn upwardly from behind the flange 40 thus releasing the belly springs for expansion as depicted in Fig. 5. The belly springs press the pads 36 into engagement with the interior of the tubing and as the pads have not been subjected to wear the assembly will accurately centralize itself in the tubing. 'Ihe assembly may then be withdrawn from the tubing and the tubing calipered as previously explained and as the pads are subjected only to the wear occasioned during the calipering of the tubing greater accuracy is possible than in the situation where the spring assembly is lowered into the well with the belly springs fully expanded and subjected to wear during the descent.

From the above-described construction it will be appreciated that the improved belly spring assembly is of relatively simple and durable construction and that by means of the adjustment afforded by the screws 25, the amount to which the inner or underlying springs 23 assists in urging the overlying springs outwardly can be varied.

Various changes may be made in the details of construction Without departing from the spirit and scope of the invention as dei-ined by the appended claims.

I claim:

l. A belly spring assembly comprising spaced supports, an outer set of belly springs spanning said supports, an inner set of springs underlying the springs of the outer set also spanning said supports, and screws mounted on the springs of the outer set adjustable toward and away from springs of the inner set to adjust the pressure exerted by the springs of the inner set in opposing inward forces applied to the springs of the outer set.

2. A belly spring assembly comprising spaced supports, an outer set of belly springs spanning said supports, an inner set of springs underlying the springs of the outer set also spanning said supports, screws mounted on the springs of the outer set adjustable toward and away from springs of the inner set to adjust the pressure exerted: bythe springs. ofthe-.inner'set opposing inwardlforces; applied ta` the Springs of the outerset, and means for lockingthe screwsL in adjusted positions.

3f. A belly spring` assembly comprising spaced supports; an outer set,4 or belly springs spanning said; supports; an inner setof'springs. underlying the springsofu the outer set. also spanning said exertedrby thespringssot'the inner set in opposing inwardforees. applied to; the springs of the outer set, and leaf, springs secured to the inner facesV of the springs of the outer'set through which the screws.. extend, said leaf springs being biased inwardly to bind upon the screws and lock the screws against rotation.

4. A belly spring assembly for use in wells, pipe and the like comprising a supporting structure, belly springs mounted thereon and biased to spring outwardly relatively thereto, a collar slidably mounted on the supporting structure, fingers on the belly springs engageable with the collar to releasably hold the belly springs in contracted position while the assembly is being lowered, and iingers on the collar engageable with the interior of the pipe to hold the collar stationary while the supporting structure is moved upwardly relatively thereto to release the belly springs and allow them to expand.

5. A belly spring assembly for use in wells, pipe and the like comprising a supporting structure, belly springs mounted thereon and biased to spring outwardly relatively thereto, a collar slidably mounted on the supporting structure, lingers on the belly springs engageable with the collar to releasably hold the belly springs in contracted position while the assembly is being lowered. ngers on the collar engageable with the interior of the pipe to hold the collar stationary while the supporting structure is moved upwardly relatively thereto to release the belly springs and allow them to expand, and assistant springs mounted on supporting structure beneath each of the belly springs and means on the belly springs engageable with the assistant springs for varying the force with which each belly spring may press outwardly.

6. A belly spring assembly comprising vertically spaced supports, an outer set of circumferentially spaced belly springs spanning the distance between said supports, said belly springs having one end bifurcated and in sliding engagement with one of said supports, an inner set of springs underlying the springs of the outer set, said inner set of springs being in contacting relationship with at least one of said supports and said belly springs, and screws mounted on the springs of the outer set adjustable toward and away from springs of the inner set to adjust the pressure exerted by the springs of the inner set in opposing inward forces applied to the springs of the outer set.

7. A belly spring assembly comprising vertically spaced supports, an outer set of circumferentially spaced belly springs spanning the distance between said supports, one end of said springs being in sliding engagement with one support, an inner set of springs underlying the springs ofthe outer set, said inner set of springs being in contacting relationship with at least one of said supports and said belly springs, and screws mounted on the springs of the outer set adjustable toward and away from springs of the inner set to adjust the pressure exerted by the springs of the inner set in opposing inward forces applied to the springs of the outer set.

8. A belly spring assembly comprising vertically spaced supports, an outer set of circumferentially spaced belly springs spanning said supports, one end of said springs being in sliding engagement with one support, an innerrset of springs underlying the springs of the outer set also spanning said supports, and screws mounted on the springs of the outer set adjustable toward and away from springs of the inner set to adjust the pressure exerted by the springs of the inner set in opposing inward forces applied to the springs of the outer set.

ARTHUR H. BRANDON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Laudermilk Aug. 22, 1933 Zaparka Dec. 8, 1936 Kemp Dec. 20, 1938 Marco Jan. 30, 1940 McCray Feb. 23, 1943 Penick Mar. 15, 1949 Lockwood Sept. 27, 1949

Images