US3654825A

US3654825A - Apparatus for loosening thread protectors from tubular bodies

Info

Publication number: US3654825A
Application number: US17372A
Authority: US
Inventors: Jan H Moddemeijer; Dirk Jogchum Zijlstra
Original assignee: Hoogovens Delfstoffen NV
Current assignee: Hoogovens Delfstoffen NV
Priority date: 1969-03-11
Filing date: 1970-03-09
Publication date: 1972-04-11
Anticipated expiration: 1989-04-11
Also published as: NL6903768A; NL153463B; DE2011405A1; DE2011405B2

Abstract

An apparatus for removing substantially hollow articles from other articles into which or around which they are clamped, the article to be removed being mainly symmetrical around an axis and the surface of the other article to which it is clamped also being symmetrical with respect to an axis so that the removing is mainly possible by rotation. The apparatus comprises a rod with two lugs at a distance from each other along the rod, the lugs having sharp protruding parts for engaging into the wall of the article to be removed. The protruding parts are directed away from each other if the article to be removed has to be engaged from the inside and are directed towards each other if the article to be removed has to be engaged from the outside. Means are present to move the protruding part(s) of at least one lug towards and away from the protruding part(s) of the other lug to allow the apparatus to be brought into the correct position with respect to the article to be removed in an easy manner and to thereafter cause the protruding parts to engage the article firmly to remove it by rotating the apparatus.

Description

O United States Patent 1 51 3,654,825 Moddemeuer et al. [45] Apr. 11, 1972 [s41 APPARATUS FOR LOOSENING 2,481,024 9/1949 Kencht ..8I/9l THREAD PROTECTORS FROM 3,094,022 6/1963 Young ..81/90 TUBULAR BODIES Primary Examiner-James L. Jones, Jr. [72] Inventors: Jan H. Moddemeiier, Heiloo; Dirk Attorney-Hall & Houghton Jogchum Ziilstra, Djakarta, both of Netherlands [57] ABSTRACT [73] Assignee: Hoogovens Delfstoffen N.V., ljmuiden, An apparatus for removing substantially hollow articles from Netherlands other articles into which or around which they are clamped, the article to be removed bein mainl s mmetrical around an [22] Wed: 1970 axis and the surface of the othir articl e 0 which it is clamped [2i] Appl. No.: 17,372 also being symmetrical with respect to an axis so that the removing is mainly possible by rotation. The apparatus comprises a rod with two lugs at a distance from each other along Foreign Application Priority Data the rod, the lugs having sharp protruding parts for engaging Mar. 1 1 1967 Netherlands ..69 03768 Wall article be rbmmd- The Pmmding P are directed away from each other if the article to be removed 52 US. Cl .;...8l/72 has be engaged mm the inside and are dbbcied Wards s 1 1m. (:1 ..B25b 13/48 each ifbe ankle be 'bmmd has be engaged fmm [58] Field of Search ..81/71 72 53.2 155- (miside- Means are Presnt Pmmding Part) 279/15 6 5. 269748 of at least one lug towards and away from the protruding part(s) of the other lug to allow the apparatus to be brought [56] References Cited into the correct position with respect to the article to be removed in an easy manner and to thereafter cause the UNITED STATES PATENTS protruding parts to engage the article firmly to remove it by rotating the apparatus. 2,542,713 2/1951 Schupbach ....81/72 Kinsey ..81/72 5 Claims, 5 Drawing Figures PATENTEBAPR 11 I972 3,654,825

SHEEIlUFZ INVENTORJ ATTORNEY PATENTEDAPR 11 I972 3,654,825

SHEET 2 OF 2 BY 7%! WW ATTORNEY APPARATUS FOR LOOSENIN G THREAD PROTECTORS FROM TUBULAR BODIES This invention relates to improvements in apparatus for removing a hollow article which is substantially symmetrical with respect to an axis and which is in rigid engagement with a wall of a second article, said wall being also symmetrical with respect to an axis, particularly for loosening a protector from a drill tube used when making drill holes in the soil for propecting or making wells for hydrocarbons.

In making such drill holes the drill tubes made of high quality steel are connected mutually by threaded ends. The tubes have on one end outer thread being somewhat conical and often having a rounded thread profile, and at the other end the tubes have inner thread, also somewhat conical with rounded profile. As the threaded parts have to suffice severe requirements of accuracy and as there is a real danger that such threaded parts will be damaged machanically or in other manner during transport, storing and manupulation, it is usual to provide such tubes at the outer ends with separate protectors. Such protectors are sleeves with outer or inner thread. Usually the quality of the steel from which they are made is lower than the quality of the steel of the tubes.

When the drill tubes have to be mutually connected the protectors are removed. It appears that often such protectors cause difficulties in removing because they are clamped too rigidly to the drill tubes, for instance by some oxidation. They sometimes are turned into or on the drill tube ends so as to be too rigidly connected thereto, which is particularly possible because the threaded parts are often a little conical in shape, or there is too rigid clamping by shockwise loads during transport, shipping and so on, so that they become more rigidly connected to the tubes than at the moment of applying the protectors to the tubes.

Protectors engaging around the tube end do not cause so many difficulties in removing as protectors engaging into a tube end. Outer protectors may easily be removed by chain spanners or wrenches or the like, but these require usually considerable space around the drill tube when applying or removing such protectors. Inner protectors are often connected to the drill tube so rigidly that they need flame cutting to be removed, so that the protector is thereby divided into parts and thus is no more suited for repeated use. In such flame cutting it often happens that the inner screw-threaded part of the drill tube is damaged. Moreover such method takes much time and is expensive.

The present invention aims at obtaining an apparatus for the purpose described which is simple, allows the protectors to be removed easily and without damage and thus allows the protectors to be used several times. The drill tubes are not damaged in their vulnerable screwthreaded parts and the removing of the protectors becomes cheap and does not take much time.

In view of the above such an apparatus according to the invention comprises a rod having two lugs extending essentially in the same direction transverse to the rod, said lugs each being provided with one or more sharp protruding parts being positioned essentially in the same line parallel to the rod, at least one of the sharp protruding parts being movable so as to vary the distance between the protruding parts of the two lugs to have the sharp protruding parts penetrate the wall of the article to be removed. The rod is suited for giving considerable torque on the protector to be removed without the need to apply high forces to said rod because it could be long or even elongated by extension parts.

It has appeared that the sharp protruding parts do not damage the protectors to such an extent that they could not be used several times. Moreover it appears that the forces applied when the sharp protruding parts penetrate into the protector do not cause deformations thereof which could make removal more difficult.

The invention will now be explained in more detail with reference to the enclosed drawings, which give two preferred embodiments of apparatus according to the invention. In said drawings:

FIG. 1 shows an inner protector in a drill tube;

FIG. 2 shows on a larger scale an apparatus according to the invention, partly in section, according to a first preferred embodiment;

FIG. 3 shows a section according to line Ill-III in FIG. 2;

FIG. 4 shows a device according to the invention in a second preferred embodiment in side view; and

FIG. 5 shows this device in a view from above as seen in FIG. 4.

In FIG. 1 reference numeral 1 shows the end of a drill tube, which at this end has an inner threaded part 2 being somewhat conically converging from the free end. For protecting this screwthreaded part a protector 3 is screwed into this end of the tube, said protector having an outwardly protruding edge or flange 4 for protecting the end face of the tube.

An outer protector is provided at the other end of the tube 1 and this is not shown. The tube 1 at said other end has an outer screwthreaded part and this usually has the same diameter as the screwthreaded part 2, so that at that other end the tube 1 is provided with a part of smaller diameter to take up such screwthread. This outer screwthread is also somewhat conical and is converging somewhat in a direction away from the concerning end of the tube. Thus fully identical drill tubes may be connected by screwing one end of one tube into an end of another tube.

FIGS. 2 and 3 show the first embodiment of an apparatus according to the invention suited only for removing inner protectors as shown in FIG. 1, but this apparatus could easily be varied to be suited for removing outer protectors or for removing both inner and outer protectors.

In FIG. 2 reference numeral 5 indicates a rod which could be rectangular in cross-section, the left end of which being shown in shortened manner serving as a handgrip for rotating by lever action. Two

lugs

6 and 7 extend from the rod and have a mutual distance which is somewhat smaller than the inner diameter of the protector 3. In lug 6 there is a screwthreaded pin 8 from steel, which is hard or which is hardened fully or at the sharp conical pointed end only. This pin engages in a screwthreaded bore of lug 6 and is easily displaceable longitudinally therein to be adjusted in position or to be replaced. Lug 7 is provided close to one free end of the rod 5 and is provided with a recess 9 near its free end, said recess 9 being bridged by a pivot pin 10 extending throughout the lug 7 and the adjacent part of the rod 5 and being kept axially in position by split pins.

Recess 9 is in part enclosed by an abutment part 11 and a pawl 12 is freely rotatable about pin 10 between two positions one being shown in FIG. 3 in full lines and the other being shown diagrammatically by a dotted line being inclined downwardly. In the position shown in full lines in FIG. 3 the pawl 12 engages the abutment 11 and in this position a hard pin 13 with a sharp pointed end screwed into a screwthreaded bore in'pawl 12 takes up a position in which it has the same axis as the pin 8 in lug 6. In this position the sharp points of

pins

8 and 13 are as far remote as possible.

To loosen and remove protector 3 from tube 1 (FIG. 1) the rod 5 is moved towards this protector and assuming that rod 1 is in a horizontal position, the rod takes up a horizontal position perpendicular to the axis of rod 1. In this mutual position the

lugs

6 and 7 are introduced into the protector until the rod 5 abuts the end face of the flange 4 of the protector to the left and to the right of the lugs, so that also the extended end part of the rod 5 contacts this end face. During this introduction of the lugs the pawl 12 hangs downwardly by its own weight at an angle of about 45 to the horizontal according to the dotted line in FIG. 3 and this inclination is in the same direction as the direction into which the apparatus has to be rotated to loosen the protector. So in the present case it is assumed that the screwthread 2 is left-handed. If the screwthread 2 is righthanded the abutment 11 should be at the other side of pawl 12 and the pawl 12 should be able to turn into the other direction by its own weight. Of course the rod 5 will not always be positioned accurately with its centerline intersecting the axis of tube 1, but will be introduced in such a way that, if

desired after being lowered somewhat, the sharp points of

pins

8 and 13 contact the inner wall of the protector.

Now rod 5 is rotated into the direction in which the protector 3 has to be loosened. This entrains that first the wall of the protector will cause the sharp point of pin 13 to rotate anticlockwise as seen in FIG. 3 so that the sharp point of pin 13 penetrates into the inner wall of the protector and by the reaction force the sharp point of pin 8 will penetrate an opposite part of the inner wall of the protector. This penetration goes on until the forces counteracting it become so high that the protector is loosened on further rotation of rod 5. Pawl 12 could turn back into contact with abutment 11 during this penetration, but the torque needed to loosen the protector could be such that the protector begins to turn loose before this position is obtained. If pawl 12 reaches abutment 11,

pins

8 and 13 are in line diametrically opposite each other.

In the embodiment of FIGS. 4and 5 the rod 5, which could be hollow for larger dimensions of protectors to be removed, has a lug 14 welded thereto. This lug has two protruding parts 15. and 16 secured together and to said lug by bolts 17 and each having teeth 18. Said teeth are positioned with their free ends in a curved path. The parts and 16 are of steel, and the free ends of the teeth are hardened or the

parts

15 and 16 are fully made of hard steel.

At some distance from this lug 14, which could be positioned near one end of rod 5, there is a rectangular sleeve 19 entirely surrounding rod 5 and taking up in and along its lower face as seen in FIG. 4 a separate clamping plate 20; The top face thereof is knurled or otherwise roughened and the underface of the rod 5 is also roughened along part of its length in this zone. Both ends 21 of the plate 20 are hooked downwardly to prevent its sliding out of sleeve 19. A handgrip 22 has a screwthreaded end 23 fitting into a screwthreaded bore in sleeve 19. Thus, sleeve19 could be firmly secured to red 5 or loosened therefrom for sliding along this rod.

On the other-face of sleeve 19, the top face of FIG. 4, there is a seat washer 24 welded to the sleeve. It has two upstanding ridges 25 each covering an angle as seen from the center of about 90..

An upstanding, mainly conical lug 26 is rotatable and slidable around a spindle 27, which is welded to washer 24 and is centrally positioned therein. This spindle has a helical compression spring 28 having a nut 29 as'a seat on top and pushing the lug 26 downwardly. The lug 26 carries a toothed block 30 of hard, steel or with hardened teeth 32, bolted at 31 to lug 26 and having teeth 32 positioned mutually in convex pattern as seen in FIG. 5.

The operation is as follows:

For removing internal protectors from tubes the rod 5 is positioned on the end face of the protector so that the

lugs

14 and 26 enter the protector. To allow this the lug 26 is turned away from the position of FIG. 5 so that the teeth 32 are closer to the teeth 18 of lug 14 than in the position shown in FIGS. 4 and This turning of lug 26 could take place by gravity with the rod 5 in a horizontal position, as the lug is not in equilibrium in view of the protruding tooth block 30, but if the spring 28 prevents this in view of the friction of the lug 26 with respect to the washer 24 the lug could. be turned by hand. Another possibility is to embody the helical spring 28 as a torsional spring by securing its ends to the nut 29 and to the lug 26 respectively, so that this spring tends to move the'lug 26 out of the position of the drawings and into the lowermost position as possible in F IG. 5, in which the block 30 is in contact with the end of the lower ridge 25. The bar 5 is introduced or moved sideways after introduction in such a way that both the teeth 18 and the teeth 32 contact the inner wall of the protector to be removed. Thereupon the bar 5 is rotated in the sense in which the protector is loosened and this will entrain that first the teeth 32 with the lug 26 will rotate back to a position in which the block 30 is positioned more radially or fully with respect to the protector, during which rotation the distance between the teeth 32 and the teeth 18 becomes larger, entraining that these teeth penetrate into the inner wall of e protector so that on further turning of the bar 5 the protector is rotated with the bar and is thus loosened from its tube.

After rotating the handgrip 22 to loosen the plate 20 it is possible to move the sleeve 19 along the bar 5 to adapt the distance between this sleeve and the lug 14 to different diameters of protectors. Moreover, it is thus possible to adapt the distance between the lugs to situations in which an outer protector has to be removed. If this has to be done the lug 26 is easily lifted by hand from the washer 24 against the action of the spring 28 and the lug is thereupon rotated about after which it is in a position, in which the tooth block 30 is in the opposite space between the ridges 25 than shown in FIG. 5, the teeth 32 thus being directed towards the lug 14. Now the device is adapted to operate on the .outside of a body to be removed such as an outer protector by cooperation of the teeth 32 with the teeth 18 of lug 14.

If will be clear that the invention could be embodied in different ways deviating from what has been described above but within the scope of the following claims.

We claim:

1. Apparatus particularly for loosening a protector from a drill tube used in drill holes for prospecting for hydrocarbons, said apparatus comprising a rod having two lugs provided with sharp protruding parts, and means for moving at least one of the sharp protruding parts so as to vary the distance therebetween, said last named means including a pivot pin connected to one of the lugs and extending in the main direction of said lug, and a member rotatable around the axis of said pin and provided with one or more of said sharp protruding parts, an abutment being provided on or adjacent to the lug for limiting the rotation of said member such that its rotation is limited to a position where the sharp protruding parts of the two lugs are substantially in line with one another parallel to the rod.

2. Apparatus according to claiml, characterized in that the other lug has sharp protruding parts directed in opposite directions about parallel to the rod and that the said rotatable member cooperates with means-to be arranged in two mutually different positions, in one of which its sharp protruding parts are directed towards the said other lug and in the other of which its protruding parts are directed away from said other lug to adapt the apparatus for removing both external and internal protectors or other hollow articles.

3. Apparatus according to claim 1, characterized in that the rotatable member is urged by. spring action into a position away from the position in contact with the abutment.

4. Apparatus according to claim 1, characterized in that one of the lugs is provided on a sleeve surrounding the rod and slidable with respect thereto, said sleeve being provided with means to be easily detachably securable in desired positions to the rod.

5. Apparatus according to claim 1, characterized in that the protruding parts are adjustable with respect to the lugs in longitudinal direction of the rod and are preferably fully detachable and replaceable from and with respect to the lugs.

Claims

2. Apparatus according to claim 1, characterized in that the other lug has sharp protruding parts directed in opposite directions about parallel to the rod and that the said rotatable member cooperates with means to be arranged in two mutually different positions, in one of which its sharp protruding parts are directed towards the said other lug and in the other of which its protruding parts are directed away from said other lug to adapt the apparatus for removing both external and internal protectors or other hollow articles.

3. Apparatus according to claim 1, characterized in that the rotatable member is urged by spring action into a position away from the position in contact with the abutment.