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Publication numberUS2207005 A
Publication typeGrant
Publication dateJul 9, 1940
Filing dateOct 18, 1938
Priority dateOct 18, 1938
Publication numberUS 2207005 A, US 2207005A, US-A-2207005, US2207005 A, US2207005A
InventorsRawley D Haas
Original AssigneeRawley D Haas
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pipe and tool joint
US 2207005 A
Images(1)
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Description  (OCR text may contain errors)

Patented July 9, 1940k UNITED STATES PATENT OFFICE .1` claim.

This invention relates to I improvements ining `eiect of the thread when subjected to a heavy threaded joints, and it is more particularly concerned with such joints as used in oil well drilling. Persons acquainted with this art know that L the loads imposed upon pipe and tool joints in making up a casing and tool string reach tremendous proportions.

It is a common occurrence that the load on the uppermost threads will run into the hundreds of l) thousands of pounds and obviously, there is always the danger of the threads collapsing by stripping completely out of the joint. This danger is more likely to occur'in the tool string than in the casing string, and for that reason the inl-b vention is herein disclosed as related to a pin and box of a tool string. But it is to be understood that the identical principle is applicable to the joints of a casing string.

Efforts have been made heretofore to improve E upon the commonly employed V or square threads by shaping the threads so that a longitudinal section through the joint makes them look somewhat like the teeth of a saw. While the top of each modified thread has been given a downward and er, outward pitch, yet -the bottom of the thread has been made either straight (perpendicular to the axis of the pipe or tool joint) or given a slight downward pitch towards said axis. The two latter arrangements have not been found as eiectual 3f) as desired, for which reason the instant improvement has been devised with the following objects: First, to provide a thread construction for a tool joint, capable of actually drawing the pin and box together upon the ultimate tightening of the4 35 latter.

Second, to insure the sealing off of the circulation of fluid through the thread passages of the tool (or pipe) joint, said sealing off function becoming increasingly more effective as the load on 40 the thread increases.

Third, to provide a tool joint having a thread of which both sides are pitched in the same general direction toward the axis of said tool joint.

43 Other objects and advantages will appear in. the following specification, reference being had to the accompanying drawing, in which:

Figure l is a central vertical section of a tool joint, the thread on the pin and in the box being 59 constructed in accordance with the invention,

Figure 2 is an enlarged section of a portion of the thread illustrating how the top and bottom are pitched in the same general direction as the axis of the tool joint,

55 Figure 3 is a sectional view illustrating the sealj the pin is screwed in to the limit.

load,

Figure 4 is a detail sectional view illustrating the principle of the invention embodied in a sharp thieasd rather than a blunt one, as in Figs. 1, 2v 5 an Fig. 1 the tool joint l comprises the pin 2 andbox Each of these elements is part of a rod section, only the rod section 4 of the pin` being partially shown. It is observed in Fig. 1 that the pin 2 is of tapermg form, as distinguished from the more commonly known type of straight-side pins in tool joints. This taper of the pin is known to afford a greater strength in making the joint than if 15 it were of cylindrical form. The extremity of the pin has a conical depression 5 in which a conical dependency 6 in the box 3 is seated when This interengagmg conical 4formation locks the inner end of 20 the pin against any possibility whatever of vibrating in the lateral direction and this is a large contribution toward keeping the pin and box screwed tight. If lateral vibration could occur, as it does in an instance wherein a conical for- 25 mat1on such as shown is not provided, said vibratlon even though minute will cause the threads to ultimately loosen.

At this point it is desired to state that the pin 2 is either solid in actual practice as shown, o1' 30 provided with a central, longitudinal bore in communication with a similar bore through the box.

In either case the conical configuration 5, 6, between the male and female members has the effect stated, namely, of locking the two together. 55 This is accomplished by the cam action between the confronting and contacting surfaces, which draws the box or female member in toward the pm or male member.

Another important effect of the tapering pin 2 is the provision of a wide thread base l. This aords strength where it is most needed. Particular attention is directed to the thread itself, the particular cross sectional shape shown constituting the underlying invention. The thread on the pin 2 is adapted to bescrewed into the thread passagev 9 in the box 3. The top l0 of the thread 8 is set at a pitch to the axis Il of the tool joint, said pitch being upward as denoted by the pitch line I2 (Fig. 2).

. The bottom of the thread 8 is also set at a pitch Y to the axis l`l, the direction of the pitch also being upward as denoted by the pitch line I4. But the pitch I4 is slight as comparedto the pitch l2. The crest l5 of the thread 8 is made blunt (Fig. 55

CII

2), this particular configuration being best adapted for rough work. But in Fig. 4 the crest I6 is made sharp, the principle of pitching the top Ia and bottom I3a in the same general upward direction toward the axis of the pin being preserved.

By virtue of having the short side or bottom of the thread on the slight incline shown, there is a strong tendency to pull the pin and box together because of the interengaged hookform of the thread in the box or female member and undercut form of the thread on the pin or male member. The bottom I3, which stands onay slight upward inclination, yet considered as a" part of the thread 8, rests and ridesupon the I companion thread I'I of the box, the top I8 of which stands at an outward decline. This riding together of these matching surfaces has the -effect of drawingthe box 3 inwardly toward the pin when the two are screwed together. The action tight interconnection.

Reference is now made to Fig. 3. The direction of the load is indicated by the arrow a. The full and dotted line positions of the thread 8 are greatly exaggerated, As the load increases there is a tendency toward` a slight clockwise turning of the thread in the direction of arrow b. The crest I5 is thus projected outwardly an extremely small distance (arrow c), thus tending to flatten the bottom I3 of the thread. 'Ihe sealing function thus improves with the increase in the load, the bending of the threads resulting in their jamming together more and more tightly, progressively securing against leaks.

But by the time that this flattening has occurred the tool joint will be under an extremely heavy load. The effect of this clockwise turning of the thread is to jam the crest I5 even more tightly into the thread passage 9 than before, thus sealing thethread passage against any possibility of iiuid entering it.

I claim:

A coupling for use in connecting a pair 0f members adapted to sustain a ponderous load, said coup-ling consisting of male and female members having matching threads, said threads having short sides inclined slightly downwardly from a perpendicular to the axis of the coupling, therev by to delizie a hook-form of the threads on the female member and an undercut form on the is that of a cam, and theresult is an extremely@ threads of-the male member, said thread configurations exercising a cam action under pressure of; the load sustained by the male member to draw saidinembers together and establish a sealing-oir function, thetops of the male threads and the corresponding portions of the female threads being pitched sharply downward in respect to said lperpendicular to the coupling axis to actas abrace.

, RAWLEY D. I-IAAS.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3046828 *Apr 17, 1958Jul 31, 1962Dzus WilliamStud having overhanging re-entrant load bearing threads and a sheet metal nut with resilient helically inclined wings
US3153356 *Dec 17, 1962Oct 20, 1964Howard K DearbornGun drill
US3191485 *Sep 11, 1962Jun 29, 1965Clarke Francis XThreaded fastening device
US3209454 *Jan 2, 1963Oct 5, 1965Gillette CoSafety razor with buttress thread
US3224799 *Jun 21, 1965Dec 21, 1965Armco Steel CorpThreaded tube joint having a metal-to-metal seal
US3251329 *Jun 8, 1964May 17, 1966Graydon SmithJib attachment system
US4209191 *Jun 16, 1978Jun 24, 1980Armco Inc.Quick make-and-break large diameter coupling
US4410204 *Jul 6, 1981Oct 18, 1983Dril-Quip, Inc.Connector
US4494777 *May 23, 1984Jan 22, 1985Vallourec, S.A.Closed angle thread pipe joint
US4587748 *Apr 12, 1985May 13, 1986Triman LimitedStudded footwear
US4610467 *Jul 10, 1984Sep 9, 1986Dril-Quip, Inc.Connector
US4907926 *Jul 29, 1986Mar 13, 1990Wing George SThread form and fastener system using the form
US5092635 *Apr 27, 1990Mar 3, 1992Baker Hughes IncorporatedButtress thread form
US5415442 *Mar 9, 1992May 16, 1995Marubeni Tubulars, Inc.Stabilized center-shoulder-sealed tubular connection
US7694835 *Jan 4, 2005Apr 13, 2010Rexam Closures And Containers Inc.Drafted neck finish having angled thread face and closure package
US7980795 *Jul 3, 2008Jul 19, 2011Seco Tools AbMulti-piece tool assembly and cutting tool
US20120093602 *Jul 9, 2009Apr 19, 2012Osg CorporationMachining head replaceable rotating tool, holder, and machining head
USRE30647 *May 31, 1978Jun 16, 1981Hydril CompanyTubular connection
USRE34467 *Apr 16, 1992Dec 7, 1993The Hydril CompanyTubular connection
DE1129125B *Dec 16, 1958May 10, 1962Atlas Bradford CompanyBohrlochgestaengeverbindung
DE1262684B *Jul 25, 1962Mar 7, 1968Theodore DzusSchraubverbindungsanordnung
DE2617667A1 *Apr 22, 1976Nov 18, 1976Hydril CoRohrverbindung
DE2717795A1 *Apr 19, 1977Nov 3, 1977Hydril CoSchwalbenschwanzverbindung fuer steck- und fassungsrohrelemente
DE2733163A1 *Jul 22, 1977Jan 26, 1978Vallourec Lorraine EscautRohrverbindung, insbesondere fuer bohrfeldrohre
DE2760197C2 *Jul 22, 1977May 30, 1985Vallourec (Usines A Tubes De Lorraine-Escaut Et Vallourec Reunies), Paris, FrTitle not available
DE3224798A1 *Jul 2, 1982Jan 27, 1983Dril Quip IncVerbindungsvorrichtung fuer zylindrische oder rohrfoermige koerper
DE3224798C2 *Jul 2, 1982Feb 17, 1994Dril Quip IncVerbindungsvorrichtung für zylindrische oder rohrförmige Körper
Classifications
U.S. Classification403/334, 411/423, 285/334
International ClassificationE21B17/08, E21B17/02, F16L15/00, F16L15/06, E21B17/042
Cooperative ClassificationE21B17/08, E21B17/042
European ClassificationE21B17/08