MXPA00001334A - Tubular connection - Google Patents

Abstract

The tubular connection (10) includes a pin member (16) having external tapered threads (20) extending from a pin nose (29) to a pin base (23) and box member (18) having internal tapered threads (32) extending from a box base (33) to a box nose (34). The tapered threads are square or near square threads having a stab (50, 60) and load (70, 72) flanks with accommodating grooves. The stab flanks (50, 60) have corner chamfers (52, 62) which engage upon stabbing the pin member (16) into the box member (18). The corner chamfers (52, 62) increase the clearances between the threads and grooves and guide the crests (58, 68) to the root (59, 69) openings upon relative rotation of the pin (16) and box (18) members. The stab flanks (50, 60) may have an increased thread width at the thread pitch line forming cam flanks which cam the threads into the grooves. The crests (58, 68) and roots (59, 69) of the threads interferingly engage.

Description

TUBULAR CONNECTION RELATED REQUESTS This application claims the benefit of the provisional application 35 U.S.C. 111 (b) Serial No. 60 / 055,325, filed on August 11, 1997 and entitled Self-Regulating Torsion Resistant Threaded Connection and provisional application 35 U.S.C. 111 (b) Serial No. 60 / 074,358, filed on February 10, 1998 and entitled Threaded Connection.

BACKGROUND OF THE INVENTION The present invention relates to tubular connections and more particularly to the threaded tubular connections used to join lengths of tubes or gaskets of the type commonly used in the oil and gas industry. In particular, the tubular connection of the present invention is a threaded, torsion-resistant, self-regulating connection. The tendency in the oil field is to reduce to a minimum the diameter of the tubular connections and to preserve the diameter of the borehole. Two types of connections in the oil field, namely smooth joints and high-performance reduced-line connections, have been used for these purposes. The external diameter of a smooth joint connection is substantially the same as the outer diameter of the tube body. In other words, the connection is contained within the thickness of the wall of the tube body. The external diameters of conventional pipe couplings are typically 10 to 13% greater than the thickness of the wall of the pipe body. The external diameter of a high-performance, low-line connection is generally 2 to 3.5% greater than that of the tube body. High-performance, low-line connections can be manufactured with or without cold-stamped sections; altered forged in hot; and links. Although they do not experience as many assembly and disassembly cycles as a drill pipe, pipe connections must also remain useful after repeated assemblies. In this way the connections should be coated to a lesser degree. An emerging technology, drilling with casing, requires coated connections with the added operating attributes of the drill pipe tool joints. U.S. Patents 4,009,893; 4,538,840; 4,570,892; 4,611,838, 4,629,221; and 4,629,224 describe various types of connections for tubular members having intermounted portions which serve to seal the connection. For example, U.S. Patent 4,611,838 to Mannesmann discloses an annular end face of the bolt member for opposing an annular flange of the box member, which lies in planes transverse to the axis of the tube. The bolt member has an unthreaded annular projection which engages a non-threaded frusto-conical peripheral zone on the box member to form a seal. A greater efficiency in the connections of reduced line and of the smooth type is its Index of compression extremely low. Typically the flank angles of the prior art threads are large, which results in large spaces between the surfaces of the threads supporting compressive loads in the total assembly. In addition, as the flank angles are reduced, the spaces between the threads must be increased to allow the threads to be inserted into the slots after assembly. In this way, prior art connections provide a greater space between the flanks of the threads. The large spaces between the threads allow the movement between the threads under cyclic loads and in this way they do not reach a hermetic connection under cyclic loads. Large flank angles and thread spaces weaken the connection during compression. The connections of the prior art can have a compression efficiency of 25 to 30% with a tension efficiency of 60%. This also causes the connection to weaken during bending. Bending is the compression on the inside of the connection and the tension on the outside of the connection. Square threads substantially lack flank angle and therefore are desirable because they provide good transfer of stress and compression load. But for the square threads to penetrate, the spaces of the flanks of the threads must be so large that the contact between the load flanks and the flanks of attack or insertion after assembly is not reached. Thus, it is commonly believed that it is not possible to insert a square thread, including a square inclined thread, into an adjustment slot without having prohibitively large gaps between the flanks of the thread. In addition, it is commonly believed that for a thread to be "incrustable" and "machinable" a hook thread must have an included angle of 15 ° or more, that a thread without a hook, such as an API trapezoidal thread, must have an included angle of 13 ° or more and that a force thread such as an Acmé stud thread or an X API thread should have an included angle of 12 ° or more. Square threads can not be easily manufactured, particularly in small diameter connections. Therefore those threads of the prior art require those included minimum angles to be insertable and machinable. The prior art connections with modified square threads use variable width threads to allow the square threads to be recessed. The wedge thread or dovetail thread of the prior art was developed to increase thread contact and achieve locking threads. A wedge thread is a thread that has load and force flanks which have different helical angles ie different loads. Since its separation is the cutting of two advances, the threads of which have a variable spacing. The wedge threads obtain their wedging by monotonically increasing the thread within the slot as one member rotates relative to the other member. The wedge threads are joined or coupled by rotational and then axial movement. The wedging of a wedge thread occurs along the axial length of the threads with the width of the larger thread being received in a smaller root opening. The connections using wedge threads produce resistance to twisting between the threads due to the different loads between the load and stress flanks, that is, a wedge-type, dovetail thread. However, the profile of the wedge thread requires multiple machining processes to cut the thread. The present invention overcomes the deficiencies of the prior art.

BRIEF DESCRIPTION OF THE INVENTION The tubular connection of the present invention includes a bolt member having external, inclined threads, and a box member having internal, inclined threads, both sets of threads have the same constant helical angle, i.e. constant advance for both flanks of attack or insertion and advance, that is to say, a thread of constant separation. The threads include inlet threads, full height threads, and outlet threads which extend from the tip of the bolt and the box members toward the base of the bolt and box members. The threads are square or almost square threads that form adjustment slots between them. The threads have crests and roots with a contact by minimum interference and flanks of attack or insertion and load with the flanks of attack or insertion having a flank angle greater than the load flanks. In addition, the > Attack or insert flanks have bevels in the corner to increase the spaces to embed the threads in the grooves. The leading or insertion flanks also include an increased thread width in the separation line to form a cam flank extending from the corner bevel to the regular insert or flank which extends towards the radius at the root of the thread.

The tip of the bolt and the base of the box form a metal-to-metal seal system and a primary torsion flange. The tip of the bolt includes a member similar to an external annular tooth that forms a first cylindrical surface, a first frustoconical surface, a first ridge and a second rim. The base of the box includes a member similar to an internal annular tooth forming a second cylindrical surface, a second frustoconical surface, a third flange and a fourth flange. The metal-to-metal seal is formed by coupling the interfering cylindrical first and second surface and the frustoconical first and second surface. The primary twist flange is formed by the coupling of the first, second, third and fourth flanges. After assembly of the connection, the threaded bolt member is inserted into the threaded box member. In the inserted position, the corner bevels on the flanks of attack or insertion are engaged to automatically center the bolt member within the box member. The corner bevels increase the spaces between the threads and grooves. During initial assembly, the bolt and box members rotate relative to each other with the corner bevels guiding the ridges toward the root openings. The cam flanks then place the square threads on the bolt member and housing in the adjustment slots on the corresponding bolt and box members. When the surface of the seal on the tip of the bolt and the base of the box are coupled, a reaction force produces a deviation of the contact of the thread of the flanks of attack or insertion to the load flanks. As the rotation continues, then the crests and roots are coupled. The applied torsion must be increased to continue forcing the bolt and box members together. As the force is increased, the bolt member is placed in compression and the box member is placed in tension. This causes the space between the attack or insertion flanks to close. When the seal surfaces are fully joined, the bolt tip stops rotating before the final assembly of the connection thereby transferring substantially all of the remaining applied torque to the threads, which are sequentially locked from the bolt tip to the base. of the bolt. Finally, after the primary torsion flange completes the coupling, a secondary torsion flange can be formed between the tip of the box and the base of the bolt. In the final mounted position, flank-to-flank contact exists in the lines of separation of the thread of the flank of attack or insertion that form a helical band of contact between the flanks of attack or insertion.

In the final mounted position, the crushing stress loads are evenly distributed along the length of the thread. The metal-to-metal seal assembly is insulated from the mounting torque so that the torsional strength increases with additional mounting torque. The present invention produces a high-performance, low-line connection with the operating characteristics of the threaded and coupled connections, integral smooth joint connections with the operation of the typical reduced-line high-performance connections, and integral threaded and coupled gaskets. altered with better performance than or at least equal to that of integral threaded and coupled or altered conventional joints, but with an external connection diameter only slightly larger, ie 0.2 to 2.2 inches (0.508 to 5.558 mm), than the body of the tube. Other objects and advantages of the invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS For a detailed description of a preferred embodiment of the invention, reference is now made to the accompanying drawings where: Figure 1 is a schematic view, partly in cross section, of a connection for use with the present invention; Figure IA is a detailed, amplified view of the secondary outer torsion flange of the connection of Figure 1; Figure IB is a detailed, amplified view of the full height threads of the connection of Figure 1; Figure 1C is a detailed, amplified view of the inlet thread, outlet of the connection of Figure 1; Figure ID is a detailed, amplified view of the primary inner torsion flange and the immobilized metal-to-metal seal system of the connection of Figure 1; Figure 2 is a cross-sectional view of the sealing system shown in Figure 1 before assembly; Figure 3 is a partial cross-sectional view of the exploded view of the threads of the connection shown in Figure 2; Figure 4A is a partial cross-sectional view of the exploded flanks of the connection or insertion of the connection of Figure 1 having an increased thread width in the line of separation of the thread; Figure 4B is a partial cross-sectional view of the exploded view of another embodiment of the leading or insertion flanks of the connection of Figure 1 having a generally planar surface; Figure 5A is a cross-sectional view of adjacent threads on the bolt member of the connection of Figure 1; Figure 5B is an enlarged, cross-sectional view of a thread of Figure 5A; Figure 6 is a cross-sectional view of the threads of Figure 1 in the inserted position; Figure 7 is a cross-sectional view of the threads of Figure 1 in the cam position; Figure 8 is a cross-sectional view of the threads of Figure 1 in the position mounted on the profile of the thread of Figure 4A; Figure 8A is a detailed, amplified view of the attack or insertion flanks of the connection shown in Figure 8 in engagement; Figure 9 is a cross section of a high torque connection, of the smooth type, which uses the present invention; Figure 10 is a cross section of a hot-forged, low-torsion, high-torque connection using the present invention; Figure HA is a cross-sectional view of the threads in inserted position; Figure 11B is a cross-sectional view of the threads of the connection in the initial mounting position when the flange bevels engage; Figure 1 is a cross-sectional view of the threads of the connection in the adjustment position when the thread separation points and the load flanks are closer to each other; Figure 11D is a cross-sectional view of the threads of the connection in the final assembly position; Figure 12A is a schematic view of a cross section of the connection in the inserted position with the bolt member and the box member just at the beginning of the assembly process, where the attack or insertion flanks of each member are just touching; Figure 12B is a schematic view of a cross section of the connection in the initial mounting position just when the two seals touch; Figure 12C is a schematic view of a cross section of the connection in the adjustment position when the two seals engage; Figure 12D is a schematic view of a cross section of the connection in the final mounting position when the seals and torsion flanges of the two members are engaged; Figure 13 is a schematic view of a cross section of the connection before the peak / root contact with the attack or insertion flanks, being raised together; and Figure 14 is a cross-sectional view of another embodiment of the connection of the present invention having a central flange seal configuration.

DESCRIPTION OF THE PREFERRED MODALITIES Provisional application Serial number 60 / 055,325, filed on August 11, 1997 and entitled Torque-Resistant Threaded Connection, self-regulated in the provisional application Serial Number 60 / 074,385, filed on February 10, 1998 and entitled Threaded connection both are incorporated as reference here in its entirety. For purposes of nomenclature, ISO CD 13679 Annex B was incorporated herein by reference. It should be noted that the threaded tubular connection of the present invention can be used in an integral joint or in a coupled joint for tubular members. In an integral joint the bolt and box members are integrally joined to the ends of the tubular members. In a coupled gasket, a threaded coupling unites the threaded ends of the tubular members. The threaded tubular connection of the present invention is applicable to all types of tubular devices in the oil field including drill pipes, pipe linings and pipes. The connection can be used on flat end tubes, cold formed stamped ends or deformed hot forged ends. The tubular connection of the present invention is typically included in a broad group identified as high performance, low line connections. It can be used in several modalities as an integral smooth joint, with or without inwardly folded sections; stamped integrally with or without stamped sections; altered, hot forged, one or both members; or coupled with or without bolt ends bent inwards. The connection of the present invention has the advantage that its tubular walls in the joint area are ultra-thin. The connection may have the same internal diameter as the body of the tubular member, preferably an internal diameter slightly smaller than the internal diameter of the tube body but sufficiently larger than the displacement diameter of the tube body to allow free passage of tools down the hole, and an outer diameter which is preferably the same or not greater than 0.22 inches (0.6 cm) greater than the outer diameter of the tubular member. Thus, the internal diameter of the connection is essentially similar to that of the tubular member and the outer diameter is preferably only 2/10 of an inch (0.5 cm) larger than the outer diameter of the tubular member. Referring initially to Figure 1, the threaded integral smooth tubular connection 10 of the present invention includes inclined threads for connecting tubular members of the oil field 12, 14. The connection 10 includes at least two coupling members, a bolt member 16 placed on the body 24 of the tubular member 12 and a box member 18 positioned on the body 42 of the tubular member 14. The outer surface of the bolt member 16 and the inner surface of the box member 18 are generally conical in shape to assist self-centering of the body member. bolt member 16 inside the box member 18 during assembly. The bolt member 16 is shown fully assembled with the adjusting box member 18. It should be noted that the tubular member 12 has a box member on its other end and a tubular member 14 has a bolt member on its other end. It should be understood that the bolt member of a connection means the male portion of a tubular member that is threaded on its outer surface and that the box member of a connection is the female portion of a tubular member that is threaded onto its inner surface by what the threads of the bolt member and the box member are interconnected to provide a connection.

The threaded connection 10 of the present invention includes sets of threads with a constant inclination, although not necessarily of the same magnitude, on the box bolt members 16, 18. The threads have a constant spacing and a constant feed. The profile of the threads is essentially the same for the bolt member 16 and the box member 18. One advantage of a constant feed thread is that the thread can be machined with a single-form tool with multiple passes of that tool , thus producing flanks of load and attack with the same advance, that is helical angle. The thread placed on the bolt member 16 preferably includes an outlet thread section 20 extending from the annular rim 22, at the base of the bolt 23 adjacent the body 24 of the member 12, to a full-height thread section. in the middle section 25 of the bolt member 16 and a section of inlet threads 28 extending from the full height threads 26 to the terminal end or tip of the bolt 29 of the bolt member 16. It can be understood that a section of threads "input" means a portion of threads having their roots machined parallel to the longitudinal axis of the tubular member, but having their ridges machined on an inclination with respect to the longitudinal axis of the tubular member, of an initial plane, the helix of construction of the ridges and roots of the threads diverge, finally reaching a full height thread. It should be understood that a section of exit threads means a portion of threads having their roots machined on an inclination with respect to the longitudinal axis of the tubular member, but having their ridges machined parallel to the longitudinal axis of the tubular member; gradually the helix of construction (machining) of the crests and roots of the threads intersects and the thread disappears. The thread placed on the box member 18 includes an inlet thread section 32 extending from the entrance end or end of the box 34 to a full height thread section 36 in the middle section 35 of the box member 18. and a section of exit threads 38 extending from the full height threads 36 to a sealing groove 40 and an annular rim 41 at the base of the box 33 of the box member 18 adjacent the body 42 of the tubular member 14. The inlet threads 28, the full height threads 26 and the outlet threads 20 on the bolt member 16 are engaged with the outlet threads 38, the full height threads 36 and the inlet threads 32 on the box member 18. The shorter height of the entry threads 28 adjacent to the tip of the bolt 29 substantially reduces the contact of the threaded flank in that area. The force transfer between the bolt and box members 16, 18 is more uniform due to the entry / exit threads. See U.S. Patent Nos. 5,413,442 and 5,462,315, both incorporated herein by reference. In a mounted tubular connection, the section of entry threads on a bolt member or box member typically corresponds to a section of output threads on the corresponding box member or bolt member, respectively. Also for greater benefit, complete input / output screw assemblies are preferred. Those skilled in the art will recognize that with the complete inlet / outlet thread assemblies, the height of the thread, critical to the operation of the connection at high elastic and low plastic stresses, is no longer a factor affecting the efficiency of the load capacity of the connection. For purposes of illustration and not by way of limitation, the connection 10 is shown as a smooth seal. Although not a standard practice in the industry for this invention, it is preferable to bend inward the end of the bolt member 16 and the outer diameter of the box member 18 in the area where the seal 46 is to be machined. To control the thicknesses in this critical area of the connection, both the box member 18 and the pin member 16 are stamped and rounded so that they can be perforated to the same size on their internal diameter. This provides a critical continuous internal profile for the tools to advance within the tube and a uniform wall thickness essential for the operation of the cyclic connection. The bolt member 16 includes a relatively thin section or portion 17a extending from the tip of the bolt 29 to the middle section 25 and a relatively thick portion 17b extending from the middle section 25 to the base of the bolt 22. The member 18 includes a relatively thin portion 19a extending from the tip of the box 34 to the middle section 35 and a relatively thick portion 19b extending from the middle section 35 to the base of the box 33. The portion of the Bolt 17a corresponds generally to the thick-box portion 19b and the thick-bolt portion 17b generally corresponds to the thin-box portion 19a. The thicknesses of the bolt and box members 16, 18 are controlled. The thin portion of the bolt 17a provides a relatively flexible cylindrical member at the tip of the bolt 29. The thin portion of the bolt 17a between the threads and the tip of the bolt 29 and the base of the case 33 allows flexibility at the bolt tip 29 allowing therefore a radial increase between the thin portion 17a of the tip of the bolt 29 when placed in compression. Because the thickness of the wall formed by the bolt and box members is thin, the connection 10 corresponds to the torsional application. During assembly by squeezing hard, after the tip of the bolt 29 has been seated at the base of the corresponding case 33, as shown in Figure ID, the case member 18 contracts radially and the bolt member 16 expands. radially Likewise, the tip 29 of the bolt member 16 contracts axially, while the corresponding portion of the box member 18 expands axially. The contraction and expansion increases the radial pressure on the threads of the connection 10 thus increasing the friction. In addition, because the bolt member 16 and the box member 18 are externally and internally conical, respectively, the radius of the threads increases from the front to the rear of the connection 10 generating a cumulative friction that is not linear with respect to the twisting of the assembly. This non-linear increase in friction increases the torsional strength of the connection 10 during assembly. Referring now to Figure 2, the seal assembly 46 is shown. The tip of the bolt 29 of the bolt member 16 includes a member similar to an annular tooth or tooth 30. The tooth 30 forms an outer cylindrical surface 97, a external frusto-conical surface 98, an annular rim 100, an internal frusto-conical surface 102, and an adjacent annular rim 31. The base of the box 33 and the box member 18 includes a cylindrical pre-inclined surface 104, a frusto-conical ramp surface 106, an cylindrical seal surface 108, an annular groove 40 and a member similar to an annular tooth or adjacent tooth 110. The annular groove 40 forms an external frustoconical surface 112, internal frustoconical surface 114, and an annular flange or surface of smaller diameter 116. The tooth 110 includes an internal frusto-conical surface 114 and an annular rim 41. The tooth 30 of the bolt member 16 is received within the groove 40 of the box member 18 and a ref annular ring 31 or bolt member 16 engages the annular rim 41 on the box member 18 to form a primary internal torsion flange 43 and a metal-to-metal, immobilized seal 46. As shown in Figure 1, the tip annular 34 of the case member 18 engages the annular rim 22 of the bolt member 16 to form a secondary external torsion flange 44. The seal system 46 forms a two-stage tooth and groove flange seal at the tip of the bolt 29 and the base of the box 33 similar to that described in the US Patent Application Serial No. 08 / 895,018, filed on July 16, 1997, incorporated herein by reference. The sealing system 46 of the present invention utilizes the interference between the sealing surfaces to achieve a metal-to-metal sealing coupling. This is mainly a function of the relative fit between the sealing surfaces of the bolt cylinder 97 and the cylinder of the case 108 and between the frusto-conical surface of the case 112 and the frusto-conical surface of the bolt, 98. The surface of the ramp of the box 106 engages the cylindrical surface of bolt 97 and guides the tooth of bolt 30 into the groove of case 40. Tooth 30 is forced into slot 40 and the tooth flange of case 41 is forced into engagement with the latter. flange of the pin 31 by the mounting torsion to achieve a relatively constant interconnection. After assembly, the frusto-conical surface of bolt 98 engages the surface of frusto-conical ramp 106. This initial coupling aligns and guides the bolt sealing cylinder 97 towards the seal cylinder of case 108 and aligns and guides it further. particularly the tooth of the bolt 30 to the groove of the box 40. As the assembly progresses, the frusto-conical surface of bolt 98 moves on a ramp surface of casing 106. Subsequently, the surface of cylindrical bolt 97, extending from tooth 30, is displaced on the surface of cylindrical casing 108 causing interference and sealing . After further tightening the assembled connection, the tooth of the bolt 30 is channeled and forced by interference into the groove of the case 40 whereby the frustoconical surfaces 98, 112 are coupled by interference and sealing. After the final tightening, the flange of the bolt 100 engages the lower cutting surface of the case 116 and the rim of the case 41 engages the flange of the bolt 31. Referring now to Figure 3, the threads of the bolt and the box are shown separately for description purposes. An edge of attack or insertion is "positive", when the angles of the thread move away from the adjacent threaded slot. The load flank, although generally angled with respect to the axis in the same direction as the stress axis, is "negative", when the thread is angled over the adjacent threaded slot. It should be understood that a threaded flank angle means the angle formed between the threaded flank and a line which is perpendicular to the longitudinal axis of the connection. The threads of the bolt on the bolt member 16 have flanks of attack or insertion and load 50, 70, respectively, which wind around the cone formed by the bolt member 16 in a helix starting from the end of the thread more close to the tip 29 of the bolt member 16 and, in a comparable manner, the threads of a box on the box member 18 with flanks of attack or insertion and loading 60, 72, respectively, which are wrapped around a helix that starts from the end of the thread closest to the tip 34 of the box member 18. It should be understood that a leading edge or insertion of the thread means the most forward or leading edge of the thread when the bolt member extends towards the thread. box member and it should be understood that the load flank of the thread means the rear flank of a thread after extending the bolt member towards the box member. Each thread on the bolt member 16 and the box member 18 has a ridge 58, 68, respectively, and a root 59, 69, respectively. For purposes of description, the front portion of the connection 10 is defined as the tip of the bolt 29 and the base of the housing 33 with the connection 10 extending rearward toward the rear of the connection 10 at the tip of the housing 34 and the base of the bolt 23. As can be seen, the threads on the bolt member 16 and the box member 18 are preferably square or almost square threads. This thread design is used on each of the threads of connection 10 with the exception of imperfect threads of reduced height, the inlet and outlet threads adjacent to the ends of the connection. These threads are only partially machined by the threaded insert, due to the intersection of the cylindrical and frustoconical sections, consequently, they have only partially formed threads. The cross section or profile of the threads preferably form a parallelogram which is square or almost square. The profile of the thread can be a real square thread with angles of the flanks of attack or insertion and load of zero or be an almost square thread which has a profile of a rhomboid. Where the profile of the thread is rhomboid, the load flanks have a negative flank angle and the attack or insert flanks have a positive load flank angle or on the contrary where the load flanks have a positive flank angle and the attack or insertion flanks have a negative flank angle. The profile of the thread can also be a trapezoid, where, within limits, the crest of the thread is slightly larger than the root of the thread and the angles of the flanks are both negative flank angles. Although the present invention will allow a ridge slightly larger than the root, to machine such a thread profile, it is first necessary to cut one of the flanks with a tool of one shape and then cut the other flank with a tool of another shape. To increase the efficiency of the compression of the connection 10, the profile of the thread is preferably a rhomboid with flanks of attack or insertion 50, 70 having a negative flank angle and the load flanks 70, 72 having a flank angle positive. To increase the tensile efficiency of the connection 10, the profile of the thread can be inverted with the leading or insertion flanks having a positive flank angle and the load flanks having a negative flank angle. In a conventional connection, the width of the thread must be less than the width of the adjustment groove to provide adequate space for the thread to be inserted into the groove, ie the opening of the root. This space allows the thread to begin its movement towards the slot after the bolt member has been inserted into the box member and a member has been rotated relative to the other member. The space or separation in an almost square thread is the difference between the width of the crest and the width of the opening of the root. The space required varies with the size of the connection. A space of at least 0.004 inches (.001016 mm) is just the required due to the variation of minimum tolerance in the width and advance of the thread. Preferably, for the thread to be inserted into the slot, the space between the thread and the slot is between 0.002 and 0.003 inches (0.00508 and 0.00762 mm) in the external diameter. Once the thread has been inserted or inserted into the groove, less space is required for the thread to continue its downward movement, towards the groove, towards the root. This displacement space is preferably at least 0.002 inches (0.00508 mm). The flanks of attack or insert 50, 60 preferably have an angle. greater than the axis 75 of the connection 10, or less radial, than the load flanks 70, 72. The angulation of the flanks is such that the load flanks 70, 72 are almost radial to the connection axis 10 and are then the flanks of attack or insertion 50, 60 which provide a peak width 88 that is slightly smaller than the width of the root 90. In this way as a practical matter, the absolute value of the angle of the flank of attack or insertion will always be greater or equal to the absolute value of the load-side angle. The leading or insertion flanks 50, 60 have a small positive flank angle 74, preferably between 0 ° and 7.5 °, with the perpendicular 76 of the central axis 75 of the tubular members 12, 14. The loading flanks 70 , 72 have a small negative flank angle 86, preferably between 0 ° and 6.5 °, with the perpendicular 76. The inclined angle is less than 12 ° and preferably 3 ° or less. More preferably, the leading or insertion flanks 50, 60 have a flank angle of 3 ° and the load flanks 70, 72 have a flank angle of 2 ° forming an included angle of 1 °. This is true for both the bolt member 16 and the box member 18. The included angle can also be negative where the root width, ie the root width without radius, without bevel, is slightly smaller than the width of the root. threaded crest. The amount of the negative angle is very light.

Referring now to Figures 3 and 7, the crests of the threads 58, 68 have a cross section width 88 which is smaller than the width of the cross section 90 of the roots of the threads 59, 69. The width 88 is measured between the leading edge or regular insert 67 and the load flank 72 and the width 90 is measured between the leading edge or insert 57 and the load flank 70. The width 88 of the ridges 58, 68 is approximately 0.002 inches (0.00508 mm) smaller than the width 90 of the roots 59, 69 to provide a space of travel between the threads and the grooves. As discussed above, square and nearly square threads can not be inserted into grooves with a gap less than 0.010 inches (0.0254 mm). Thus, although 0.002 inches (0.00508 mm) are suitable for the displacement space, it is not sufficient to insert the threads into the slots. The connection 10 of the present invention is provided with guide surfaces on the flanks of attack or insertion 50, 60 of the threads, to move the thread toward the opening of the slot and to test the thread towards the slot. The guide surfaces on the attack or insertion flanks are bevels or multiple inclinations that have different flank angles. It is these multiple inclinations that allow the square or almost square threads to be inserted or embedded in the square or almost square thread grooves to subsequently bring the threads to the adjustment slots. The guide surfaces preferably include two flanks of attack or inclined insertion or a flank of attack or insertion of three inclinations. Referring now to Figures 4A and 4B, the present invention includes two modes of the attack or insertion flanks 50, 60. The attack or insertion flanks 50, 60 may have after inclinations as shown in Figure 4A or two inclinations as it is shown in Figure 4B. In each embodiment, the flanks of attack or insertion 50 on the bolt member 16 have a chamfer at the corner 52 and the attack or insertion flanks 60 of the box member 18 have a chamfer at the corner 62. Referring in particular here now to Figures 4A, 5A and 5B, the leading or insertion flanks 50, 60 include three inclinations, namely the corner bevels 52, 62, cam flanks 54, 64 and the regular attack or insertion flanks 57, 67 The three inclinations form the guide surfaces on the flanks of attack or insertion 50, 60. As shown in Figures 5A and 5B, there is shown an elongate flank or insert 50 on the bolt member 16, which is also illustrative of the leading flank or insert 60 on the box member 18. The bevel of the corner 52 includes a flat part 51 and a radius of the corner 53. The radius 53 extends from the ridge 58 to the flat part 51 The flat part 51 extends from the radius 53 and intersects with the cam flank 54. A bevel is a controlled flat part and a radius that allows the crest to slide towards the root with very little space. Each of the corner bevels 52, 62 has a radial height 63 at least as large as the step height 75 of the thread. The height 63 of each bevel at the corner 52, 62 need not be greater than the step height 75 of the adjacent thread. The gradual height 75 of the thread is a function of the separation and inclination of the thread. There are no practical reasons for extending the bevels of the corner 52, 62 beyond the separation lines 56, 66 since beyond that point, the crests of the thread 58, 68 will come into contact with the roots 59, 69 preventing the additional cam action of the threads. Referring now to Figure 6, the flat parts 51, 61 on the bevel at the corner 52, 62 respectively cause the threads to be deflected forwardly in the connection 10 sufficiently for the bevel to provide more space in the insertion position to allow the insertion of the thread into the groove adjustment. In the insertion position, the engagement of the corner bevels 52, 62 provides a space 79 of at least 0.010 inches (0.0254 mm) and preferably a space 79 of approximately 0.020 inches (0.0508 mm). The angle of the flat portions 51, 61 of the bevels of the corner 52, 62 determines the space 79 between the thread and the slot to allow the thread to be inserted into the slot. To provide an adequate space 79 between the width of the thread and the opening of the root, the preferable elevation over the flat portions 51, 61 of the bevels of the corner 52, 62 is 3 to 1 (18.5 °). The elevation is preferably in the range of 2 to 1 (26.5 °) to 4 to 1 (14 °) with 3 to 1 being preferred. The spokes 53, 63 at the end of the flat parts 51, 61 allow a less inclination gradual. Referring now to Figure 4B, the leading or insertion flanks 50, 60 have two inclinations. The leading edge or insert 50 of the bolt member 16 includes a bevel at the corner 52 with a radius 53 extending from the crest of the thread 58 to the flat part 51 with the flat part 51 intersecting with the leading edge or regular insert 57 which extends towards the radius of the corner 73 at the root 59. The leading flank or insert 60 of the box member 18 includes a corner bevel 62 with a radius 63 extending from the crest of the thread 68 to a flat part 61 with a flat part 61 intersecting the leading edge or insert 67 which extends to the radius of the corner 71 at the root 69. The leading edge or regular insert is the leading edge or original insertion with the angle of the flank of attack or original insertion and is a flat, straight surface, which extends towards the root. The flat portions 51 and the spokes 53 on the bevels 52, 62 allow the ridges 58, 68 to move towards the openings 77 of the roots 59, 69 without joining as a result of some misalignment, eccentricities or other deviations of the actual tube of cylinders. (theoretically) perfect. When the connection is made, the threads move towards the adjustment slots because when one member rotates with respect to the other, the diameter of the pin ridges becomes larger and the diameter of the threads of the smaller box (as a function of the inclination of the respective cones) causing the ridges 58, 68 to move towards the openings 77 of the roots 59, 69. The bevels 52, 64 preferably also have a "positive" angle to help automatically center the bolt member advancing 16 towards the box member 18 without unnecessarily coupling the edges of the threads. The corner bevels 52, 62 of the present invention not only form an automatic centering effect such as that of U.S. Patent 5,462,315, but also when appropriately dimensioned they provide space, which allows the load flank of a member to pass through the body. load flank of the other member in the insertion position; consequently, allowing the threads to engage after the assembly by rotation. Ridge-to-peak coupling, a problem with square slanted threads, which prevents the connection assembly from clogging. The flank or thread insertion bevels 52, 62 on the full height threads allow several of the threads on the bolt member 16 and the box member 18 to be aligned by engagement prior to rotational mounting. Desirably, at least half of the threads are also coupled in this way. Referring now to Figure 8, ridges 58, 58 and roots 59, 69 have an average radial interference at 81, 83, preferably from about 0.0010 to 0.0015 inches (0.0254 to 0.0381 mm) of the diameter of the connection. The interference between the crests of the thread 58, 68 and the roots 59, 69 keeps the bolt members in the box 16, 18 in a cylindrical or round configuration. The interference interval is 0.003 to 0.010 inches (0.0762 to 0.254 mm) which is 0.0005 inches (0.0127 mm) of tube diameter to 0.0015 inches (0.0381 mm) of tube diameter. This interference contributes to approximately 25 to 33% of the elastic limit of the tube material. It should be understood that the crest of the thread means the location of the thread in which the tubular member wall has been machined to its minimum depth and defines the largest diameter of a thread and the smallest diameter of a box thread and it should be understood that The root of the thread means the place of the thread in which the wall of the tubular member has been machined to its maximum depth and defines the largest diameter of the thread of the box and the smaller diameter of the thread of the bolt. There is a nominal space of 0.002 inches (0.0508 mm) between the widths 88 and 90 to allow the thread to continue its travel into slot 77. The gap interval between the thread and the slot is 0.001 to 0.004 inches (0.0254 to 0.1016). mm). A gap of 0.002 inches (0.0508 mm) between the thread and the slot will not allow the thread to be embedded in the slot. The bevels at corner 52, 62 are required to increase that space to allow embedding. A difference of 0.002 inches (0.0508 mm) in widths 88, 90 provides a ratio of 0.99 of the width of the thread to the root opening. The ratio of the width of the thread to the width of the thread is preferably 0.95 or greater. The preferred range is from 0.98 to 1.0 and more preferably is 0.99. Referring now to Figures 4A and 5B, the embodiment of Figure 4A has flanks of attack or insertion 50, 60 which have an increased thread width 55, 65 in the lines of separation of the thread 56, 66. The width of the thread of the separation line 55 of the leading flank or insert 50 of the bolt member 16 forms a cam flank 54 which extends from the bevel of the corner 52 to the separation line 56 of the bolt thread and a flank of attack or regular insertion 57, which extends from the separation line 56 to the radius of the corner 73 of the root 59. Likewise, the increased thread thickness 65 of the attack flank or insert 60 of the limb box 18 includes a cam flank 64 which extends from the bevel of the corner 62 to the separation line 66 of the threads of the box and a flank of attack or regular insert 67 which extends from the line of separation 66. to the radius of the corner 71 d e the root 69. As best shown in Figure 5B, the angle 74 of the regular attack or insertion flanks 57, 67 is 2 °, the angle 78 of the cam flanks 54, 64 is 9.46 °, and the angle 80 of the flat parts of the corner 51, 61 is 18 °, ie from 3 to 1. These are the approximate preferred embodiments for these angles. As shown in Figure 4A, the cam flanks 54, 64 adjacent the ridges 58, 68, respectively, form a bevel angle 78 with the perpendicular 76. The corner bevels 52, 62 form a bevel angle 80. with the cam flank 54, 64. These angles cause the spaces 82, 84, shown in Figure 3, to be formed between the threads after assembly. The threads may have no space, a slight gap or positive interference in the thread separation lines 56, 66 due to the increased thread widths 55, 65. The increased thread widths 55, 65 in the separation lines of the thread 56, 66 of the flanks of attack or insertion 50, 60 respectively are preferably the same as the nominal space between the load flanks, that is to say 0.002 inches (0.0508 mm). The width of the thread 55, 65 in the line of separation of the thread 56, 66 is preferably equal to the width of the opening of the root in the separation line. After the load flanks 70, 72 make contact, the cam flanks 54, 64 place the load flanks 70, 72 together when the thread is inserted further into the slot thus closing the space on the load flanks 70, 72 to zero plus less tolerances that is between zero and 0.001 inches (0 and 0.0254 mm). By adding cam bevels 54, 64 extending from the end of the flat portions 51, 61 to the thread separation lines 56, 66, there is actually a zero gap between the threads and the grooves after engagement. After this lifting action, it is possible to have an interference fit between the threads, that is, the width of the thread could actually be slightly larger than that of the slot in the thread separation line. Since a space was artificially injected between the load flanks 70, 72 when the thread was inserted into the groove, the guide surfaces can be threaded into the groove where the thread is larger than the groove in the line of separation. the thread 56, 66. When the thread moves down towards the groove, the artificially induced space 79 closes and finally produces an interference between the threads. Positive interference in the separation line 56, 66 requires an increase in the torsion to close the threads but does not reach movement between the flanks of the thread when the connection is "placed in compression." As shown in Figure 8A, the increase of the width of the thread 55, 65 can form a helical linear contact or have a width to form a band or batten contact in 87. A slat contact can occur naturally in the separation lines 56, 66 due to the Poisson effect when additional torque is applied in the final assembly Although the maximum dimension of the widths of the thread 55, 65 is preferably located in the line of contact of the thread 56, 66, it can be located between the lines of separation of the thread 56, 66 and the ridges on the thread 58, 68, that is to say slightly radially outward of the lines of separation of the thread 56, 66. This ensures a contact in band or strip between the flanks of attack or insertion. 50, 60 in the separation lines 56,, 66. The location of the widths of the thread 55, 65 also allows the regulation of the degree of coupling in 87 between the flanks of attack or insertion 50, 60. As shown in Figure 6 with the connection 10 in the initial insertion position, the bevels of the corner 52, 62 allow an initial space 79 of 0.020 inches (0.508 mm) between the load flanks 70, 72. With the corner bevels 52 62, as shown in Figure 4A in initial engagement to properly align the ridges 58, 68 with the roots 59, 69, this 0.020 inch (0.508 mm) space is sufficient to allow the threads to move into the slots when mount in a rotating way. Further, as shown in Figure 7, the cam flanks 54, 64 of Figure 4A guide the displacement of the threads within the adjustment slots 77. Those flanks provide a lifting action for raising the thread to the slot. The lifting action is a forced multiplier due to the inclination on the threads. The bevels of the corner 52, 62 and the cam flanks 54, 64 allow the ridges 58, 68 to slide into the groove 77 of the roots 59, 69 in a very tight manner so that very little space 73 is required between the load flanks 70, 72. As shown in Figure 7, in the mounting position, the 0.020 inch (0.508 mm) space 79 after insertion closes to the displacement space 73 of 0.002 inches (0.0508 mm) . In this way, a tight fit is achieved within the thread profiles while the threads on the bolt members and housing 16, 18 are still received in the adjustment slots in the corresponding non-union box or bolt members which occurs in the prior art connections with almost square thread profiles. Referring now to Figures 8 and 8A, the leading or insertion flanks 50, 60 are shown in the final mounting position. Preferred flank angles, and proper sizing of the thread width and grooves, also cause the widths of the threads 55, 65 of the preferred strike or insert flanks 50, 60 to engage in a contact therein, or in narrow strip in its separation lines 56, 66 thereby forming a helical or narrow ribbon contact at 87 between the leading or insertion flanks 50, 60 in the assembled position. The threads must be dimensioned appropriately for the linear or narrow strip contact at 87 as well as for the bevels 52, 62. This linear and helical contact or narrow strip at 87 results in a linear or narrow rib bead that is extends throughout the length of the propeller that absorbs the torsion. After the load flanks 70, 72 engage, the cam flanks 54, 64 set the thread widths 55, 65 together allowing the space 89 shown in Figure 13 between the flanks of attack or insertion 50, 60 to be Close to zero, and turn even slightly, a space less than zero. Referring now to Figures 9 and 10, Figure 9 shows a high-torque connection, smooth type with secondary torsion flange 44, inlet / outlet threads 20, 32, threads that interfere diametrically, height complete, 26, 36, the outlet / inlet threads 38, 28, the primary torsion flange 43 and the seal assembly 46. In Figure 10 a high torque, reduced linear, heat forged connection with the secondary twist flange 44, input / output threads 20, 32, diametrically interfering threads, full height, 26, 36, exit / inlet threads 38, 28, primary twist flange 43 and mounting seal 46. Alternatively, in the case of a coupled connection (not shown), a coupling joins two bolt members with two box members. Each of the bolt members comprising the connection has a seal assembly on both ends followed by a single threaded section. Each coupling has two corresponding seal assemblies in the center with corresponding threaded sections emanating towards the coupling end. A coupling mounted on a tube will thus produce a threaded bolt and box gasket. See for example US Patent Re. 34, 467. Referring to Figures 11 and 12, the sequential assembly of the connection 10 is shown. The following is a description of the assembly of the connection 10 of the present invention. Referring now particularly to Figures 6, HA and 12A, the connection 10 is shown in the embedded position where the bolt member 16 has been embedded in the box member 18 to begin the assembly process. The external conical shape of the bolt member 16 and the internal conical shape of the box member 18 initiates the alignment of the bolt member 16 within the box member 18. The bevels 52, 62 on the flanks of attack or insertion 50, 60, respectively, they engage after the box member 18 has received at least half, and preferably three-fourths of the pin member 16. At this stage, on the leading or insertion flanks 50, 60 are just in contact. The depth of the insertion can be regulated by the inclination and the separation of the threads. The coupling of the bevels 52, 62 automatically further aligns the bolt member 16 within the box member 18. The engagement and alignment of the corner bevels 52, 62 deviates the bolt member 16 into the box member 18 for providing the necessary insertion space 79 shown in Figure 6 and allowing the threads on the bolt members and box 16, 18 move towards and are received in the openings of the respective adjustment slots 77 on the corresponding case and pin members 18, 16. The primary and secondary torsion ridges 43, 44 and the seal assembly 46 have not been coupled yet. After the initial contact of the bevels 52, 62, one member rotates with respect to the other member. During the initial revolutions or rotations of one member with respect to the other member, the threads move towards the mouth of the opening of the root or groove when the threads are guided by the bevels of the corner 52, 62, The guide by the bevels from the corner 52, 62 stops after a sufficient number of rotations has been made, whereby the diameter of the thread has been increased by a distance equal to the step height 75 between the adjacent threads shown in Figure 5A. At that time, the threads enter the adjustment slots. Once this occurs, no further action is required to insert the threads into the slots and the insertion space 79 can be reduced to the displacement space 73. In addition the connection 10 is axially immobilized but there has not yet been any interference between the surfaces of the seal or between the threads. There is a minimum space between the threads, however, at this point in the assembly. Referring to Figure 11B and 12B, the connection 10 is shown in the cam mounting position. The rotation at each low torsion is now applied to move the threads of the bolt and box members 16, 18 from the insertion position to the lifting position. When this torsion is applied, the connection 10 moves both axially and radially together with the connection assemblies. The bevels 52, 62 have guided the cam flanks 54, 64 on the leading or insertion flanks 50, 60 towards the coupling as shown in Figure 12B. In this way, the ridges 58, 68 have now been received by the adjustment grooves 77 of the grooves 59, 69. Initially only the leading or insertion flanks 50, 60 are in contact. The load flanks 70, 72 have a space up to the displacement space 73 of 0.002 inches (.00508 mm) between them. When the crests 58, 68 are brought to the roots 59, 69, the connection 10 becomes relatively rigid and lasts immediately after the connection 10 is in the middle of the assembly, essentially acting to align and center the bolt members and box 16, 18. The insertion of the square thread into a square slot with little space between them causes the connection 10 to be tightened to three quarters of the assembly as shown in Figure 11B. When additional rotation occurs, the threads are raised by the cam flanks 54, 64 towards the openings of the roots or grooves with the threads still mounted on the leading or insertion flanks until the space between the load flanks 70, 72 converts into the displacement space 73. The bolt member 16 rotates freely within the box member 18 so that there is little or no interference surface on the threads or on the seals and flanges. This relatively free rotation continues until the outer cylindrical surface 97 (Figure HA) on the tip of the bolt 29 engages the surface of the ramp of the case 106 adjacent to the base of the case 33. As shown in Figure 11B , the surfaces of the seal assembly 46 begin to engage at 92. This is the initial interference between the bolt member 16 and the box member 18. The strong tightening torque can not be applied to the connection until there is some interference. Once the ramp interference occurs, then there is a reaction that resists the axial displacement of the bolt member 16 towards the box member 18 which initiates the deflection of the contact of the strike flanks or insertion 50, 60 towards the load flanks 70, 72. When the contact is transferred from the flanks of attack or insertion 5060, towards the load flanks 70, 72, the torsion begins to increase due to the contact between the surfaces of the seal and the sealing system 46 and between the load flanks 70, 72. Referring now to FIGS. 11C and 12C, the Connection 10 is shown in the initial sealing position. The application of additional twisting and mounting causes the bolt and box members 16, 18 of the connection 10 to be further pulled together axially and radially as the threads move in the helix of the adjustment slots 77. The displacement continues until the Tooth 30 of bolt member 16 begins to be inserted into groove 40 of housing member 18. Frustoconical surfaces 102, 114 between tooth and groove 40 have not yet come into contact. The surface of the cylindrical pin 97 is still moving towards the surface of the ramp 108. At this point, the creases of the thread 58, 68 and the roots 59, 69 begin to interfere. The threads interfere minimally with the threads coupled in a complementary manner until they are almost completely assembled. When additional twist is applied on the connection 10, the contact areas between the crests 58, 68 and the roots 59, 69 of the threads increase. The root-peak combinations near the tip of the bolt 29 are first engaged. This is regulated by the differences in the inclination between the bolt and box members 16, 18. After the primary torsion flanges 43 are actuated together, both of the root of the box member 69 / crest of the bolt member 58 and the root of the bolt member 59 / crest of the box member 68 are coupled by interference in the range of about 0.0010 to 0.0015 inches (0.0254 to 0.0381 mm) of the diameter of the connection depending on the combination of the wall thickness and the tolerances of the particular connection 10. The more applied torsion, the larger the contact areas so that the net effect is the locking of the threads as described above. The tooth of the bolt 30 then begins to be inserted into the groove of the case 40 to begin generating larger reaction forces with the torsion increasing substantially. There is some initial force transfer and torsion transfer when the tooth 30 enters the slot of the box 40 whereby the immobilization process begins. The locking means does not transmit more torque to that portion of the bolt member 16 and that portion does not move further when the mounting torque is increased. When interference is accumulated in the thread, the Poisson effect begins, although small at this point. In addition, the thin portion 17a of the bolt member 16 begins to be placed in compression and the thick portion 19b of the box member 18 begins to be placed in tension. The walls of the bolt members and casing 16, 18 are sufficiently thin so that compression of the thin portion of the bolt 17a causes it to expand radially and the tension of the thick portion of the casing 19b causes it to contract radially. The compression of the thin portion of the bolt 17 and the tension of the thick portion of the box 19b places sufficient force on the threads to increase the diameter of the bolt member and decrease the diameter of the box member (Poisson effect). Since the bolt and box members 16, 18 have thin walls, when the bolt member 16 is in compression and the box member 18 is in tension, the Poisson effect, the crush pressure between the threads of the members of bolt and case 16, 18 actually increases and thereby increasing the friction and the torsional strength of the threads. In the initial sealing position, the threads deviate from the coupling of the flank of attack or insertion to the coupling of the load flank producing space 89 between the flanks of attack or insertion 60, 70. This deviation is caused by the interference of the thread and the seal developed between the members of bolt and box 16, 18. In this way, a strong tightening torque must be applied to continue the rotational mounting of the members 16, 18 which in turn forces a change in the flank contact of the flanks of attack or insertion 50, 60 to the flanks. flanks of load 70, 72 of the threads. In other words, the loading flank is required to act, i.e. apply twisting, to the bolt and box members 16, 18 which interfere together. As shown in Figure 13, after contacting the load flanks 70, 72 and the additional rotation, the increased thread widths 55, 65 move together on the leading or insertion flanks 50, 60 and again engage. that the cam flanks 54, 64 elevate the threads together in the separation lines 56, 66, thereby closing the space 89 between the leading or insertion flanks 50, 60. As more torque is applied to the connection 10 , the flanks of attack or insertion 50, 60 come into contact at 87 and begin to remain under load. Referring now to Figures 8, 11D and 12D, the connection 10 is shown in the final assembly in the fully tightened position. It is required to apply an additional mounting torque to seat the bolt tooth 30 in the groove of the case 40 and force the torsion flanges of the seal 31, 41 and the flanges 100, 116 together to complete the assembly of the seal 46. The assembly of seal 46 is reinforced and stabilized by the interaction between the frustoconical surfaces of seal 98, 112, the torsion flanges of seal 31, 41 and 30, 116 and the complementary input / output coupling threads 20, 32 and 38, 28 which are very close. In the final assembly, the thin portion of the bolt 17a remains in compression and the thick portion of the box 19b remains in tension. Once the seal assembly 46 has been fully seated, the connection 10 will not move more axially in the immediate area of seal assembly 46. This causes the locking process to move from the front of the connection to the after the connection. Once the tooth 30 engages the bottom of the groove of the case 40, the axial movement of the bolt tip stops substantially after any further rotation of the tip of the bolt 29. However, a movement of the bolt can continue. to the box, relatively axial, small, in the area behind the seal assembly 46 and partially in the inlet / outlet sections of the threads. Any additional torsion is transferred to the threads that start at the front and then extends to the back of the connection. When the tip of the bolt 29 rests against the base of the case 33 and additional torque is placed on the connection 10, the transfer of the torsion and the subsequent locking of the threads torsionally isolates the seal assembly 46. When the connection 10 transfers essentially all the remaining torque applied to the threads, the seal assembly 46 and the primary torsion ridges 43 are insulated to the applied mounting torsion, and this is so over a wide torsional range. In this way, the metal-to-metal seal assembly 46 is immobilized and isolated from the twisting of the assembly. As more torque is applied to the connection 10, the additional torque moves up and out of the tip of the bolt 29 and is placed on the threads extending back and forth from the connection 10. When the front threads close to the tip of the bolt 29 begins to be immobilized with the additional torque, the torsion moves backward in the connection 10 and is transmitted to those threads further back on the connection 10. This causes the threads to extend back and forth from the connection 10 for sequential immobilization when twisting is applied thereby increasing the tightness of the connection 10. The profile that forms the thread in this way exhibits an increase in the torsional strength with the increase in the twist of the assembly. This continues until the connection is completely immobilized in the tight assembly. An increase in the torsional strength of the assembly occurs because each sequentially immobilized thread has a larger diameter, in this way more surface area absorbs the applied torsion. In other words, the greater the torsion that is applied to the connection, the more the resistance to torsion until the elastic limit of the material is reached. The mounting torque for tightening the connection is regulated so that the locking of the aforementioned thread occurs at least in several full-height threads near the end of the box member 18. At the end of the box member 18, the flange secondary torque 44 is designed to be normally free or play freely at a substantial excessive torque. In this way, the threads of the bolt and box at the end of the box member 18, the larger diameter portion of the threads, continue to maintain contact of the load flank to the loading flank, which is necessary to maintain the capacities of joint strength or joint. It should be appreciated that the tip of the case 34 of the case member 18 should not be permanently attached to the base of the bolt 23 and prevent compression of the tip of the bolt 29 against the base of the case 33. If the tip of the case 34 protrudes before the tip of the bolt 29, then the threads will not be immobilized in the preferred order and avoids the application of greater torsion. In the present invention, by the natural Poisson effect, with an interference thread, the box member 18 elongates and becomes diametrically smaller and the bolt member 16 becomes shorter and diametrically longer when the contact of the load flank. All the tension in the bolt member 16 has dissipated at the end of the connection assembly. All the tension is in the box member 18. In this way, the tip of the box 34 and the base of the pin 23 should touch each other. The contact point of the load flank moves away from the point of nullification of the input / output threads and moves towards the connection 10 by expanding the box member 18 and contracting the pin member 16. The critical point moves under tension loading from the cylinder at the outlet of the threads to the output threads itself making the connection less efficient. In this way, the arrangement of the tip of the box is undesirable. When the threads are fully engaged, the bolt and box members 16, 18 engage the widths of the threads 55, 65 with zero space and the attack or insert flanks 50, 60 are closed so that the flanks of attack or insert 50, 60 are engaged in the separation diameters 56, 66 of the threads. This contact ideally forms a helical contact line or band at 87 which extends the entire length of the thread propeller, less than half the length of the complementary coupled thread entry / exit torque at the pin point 29 and half the length of the complementary coupled thread entry / exit torque at the tip of the case 34. After protruding, the Poisson effect causes the case member 18 to elongate and its diameter to become smaller and smaller. the bolt member 16 is short and its diameter is increased, the contact between the widths of the threads 55, 65 of the flanks of attack or insertion 50, 60 increases in size to a contact in ribbon or ribbon in 87, better shown in Figure 12D. This increases the capacity of torsional absorption of the threads. The relative rotational displacement between the threads of the bolt and the box is slightly larger at the end of the box member 18 than at the end of the bolt member 16. Also since there is no opposing external projection, the interference of the threads near the The end of the box member 18 causes the box member 18 to expand in diameter and by the Poisson effect between the contact axially thereby maintaining the contact of the total load flank, thereby progressively increasing the contact of the thread and the resulting resistance to twisting. In the fully assembled position, the threads are now coupled on (a) the load flanks 70, 72 of the two bolt members and threaded case member 16, 18 (b) the ridges 58, 68 and the roots 59, 69 of the two threaded bolt members and threaded case member 16, 18, and (c) in a single "coupling band" at 87 along the length of the flanks of attack or insertion 50, 60 of the two threaded bolt members and the threaded box member 16, 18. When additional torsion is applied to the connection 10, the reaction between the load flanks 70, 72 and the assembly combination of the seal 46, the ridges 43, 44, the roots 59, 69 / ridges 58/58, and the leading or insertion flanks 50, 60 comprise a threaded connection 10. In summary, the different positions include the initial insertion position, the position of assembly by cams, the initial sealing position, the interference of the root and the crest, the coupling of the tooth and the groove, and then the assembly by final twisting. Also as can be seen the ridges 58, 68, the roots 59, 69, the flanks of attack or insertion 50, 60 and the load flanks 70, 72 of the threads are in full engagement when the connection 10 is fully assembled. The crests 58, 68 and the roots 59, 69 come into radial contact with each other just before the total assembly, so that the connection 10 is torqued to its use condition, the supporting surfaces tensioning the connection 10 and resisting. the torsional load, are the different crests of the thread, roots and flanks of the threads. The threads, and specifically the relationship between the interference of the root and the crest and the coupling of the flanks, are designed so that these crushing forces are evenly distributed along the length of the thread of the connection. Due to the helical coupling of the threads and the balance of the components of the radial force of the flanks of attack or insertion and loading, the expected stresses are controlled in the bolt member 16 and the box member 18. There is no radial space between the crests of the thread of a member and the roots of its coupling member when the connection is fully assembled. The connection 10 forms a metal-to-metal pressure seal 46, a primary torsion flange 43, a secondary torsion flange 44 and self-regulating, twist-resistant threads that are not "wedge" or "dovetail" design. The torsion-resistant threads insulate the seal 46 and the torsion flanges 43, 44 against deformation caused by the twisting of the excessive mounting. The use of inlet and outlet threads substantially eliminates all slots, voids, and other spaces between the threads. The radii of the corner 61, 71 and the bevels of the corner 52, 62 can form receptacles 82, 84, as shown in Figure 8, which receive any thread lubricant used in the assembly of the connection 10. During the dismantling the connection, the connection is discharged from below the end of the box. While during assembly, the connection is loaded from outside the end of the bolt. The connection 10 reaches this torque distribution by sequentially increasing the load bearing area within the threaded portion of the connection when mounting torque is applied to the connection. Another feature of the present invention includes a connection where the threads are fully engaged to distribute all the crush stresses that resist twisting assembly, torsional loading and sealing along the entire length of the thread. As a result of this uniform distribution, the external diameter of the connection can be made smaller even though it still bears the same load as the previous connections. Likewise, all the torsional load of the connection while in use is completely in the threads and is distributed along the length of the thread. Therefore, an externally applied over-torque will not precipitate an over-torque or failure of the sealing system 46. By distributing the mounting torque applied to the threads, the connection 10 maintains the integrity Structural and pressure over a much higher and higher applied torsional range than the prior art with similar physical dimensions to the relatively modest thin line dimensions of this connection. The dimensioning of the thread of the bolt in relation to the thread of the box is such that there is contact after the final assembly to provide an effort of crushing of immobilization contact around the entire thread of and on almost all along the threads, except roots and ridges in the entry / exit sections. In this way, not only the crush stress, but also the primary external pressure and secondary internal pressure seal and the torsional load is distributed within the threads along the length of the threads and is not provided or shared by any other structure related or associated with the threads. Sealing by the primary internal pressure is of course provided by the internal pressure seal system. The specific geometry of the thread shape is important for the connection 10, that is to say a square or almost square thread with a specific crest width and tightly controlled 88, so that the opening 90 of the threaded slot is only slightly larger than the width 88 of the tooth of the thread; thus forming an extremely narrow fit after assembly. The height of the threads is also tightly controlled so that the diametral interference is controlled both in intensity and in relative location to achieve a sequential torsional coupling during assembly. The substantially square threads and the square grooves on the bolt members and box 16, 18 with the threads being only slightly smaller than the adjustment grooves allow the connection 10 to reach an immobilizing coupling when the connection 10 is tightly engaged. The locking of the preferred thread / seal of the present invention is achieved with the strike or insert bevels 52, 62 which allow the bolt member 16 to be embedded in the box member 18 and which allows the threads, which are essentially square, they are coupled together. In other words, the crests 58, 68 and the roots 59, 69 are substantially square and the bevels 52, 62 allow the square crests 58, 68 to be received within substantially square roots 59, 69 to provide a very tight connection. Also, the widths 88, 90 of the ridges 58, 68 and the roots 59, 69 are regulated, so that they are almost the same, thus reaching a non-substantial space in the threads. This is allowed due to the alignment of the insertion flank using the bevels 52, 62. The threads are immobilized as the torsional strength increases. In other words, the torsional strength does not increase linearly when the mounting torque increases. The torsional strength can be defined as the resistance to rotation of one member with respect to another member. The connection of the present invention includes a metal-to-metal seal system and threads that are locked in a thread configuration, whereby the seal is immobilized and isolated from the mounting torsion, thereby providing a torsional strength. extremely high The connection of the present invention has compression and tension characteristics that exceed those of the prior art. In the preferred embodiment, the compression characteristics of the connection are slightly better than the traction characteristics due to the coupling of the pin tip and the base of the box. In voltage mode, the efficiency of the connection or resistance of the connection is a function of the cross-sectional areas of the coupling of the threaded members. The cross-sectional area of the seal surface is in a central flange or bolt tip and does not add to the tension characteristics of the connection solely to the compression characteristics. With square threads, the contact areas of the thread in tension and compression are substantially the same. The additional contact area of the seal surfaces adds compression to the compression characteristics of the connection. Referring now to Figure 14, there is shown another embodiment of the connection of the present invention. The connection 100 includes a bolt member 104 and a box member 106 formed on the ends of another tubular member 108. The connection 100 further includes a central flange seal 110 located approximately at the longitudinal midpoint of the connection 100 and described with more detail in U.S. Patent 5,462,315, incorporated herein by reference. The seal of the central flange 110 forms two gradual threads on the bolt members and housing 102. 106. The seal of the central flange 110 is a doubly immobilized flange constituted of a first configuration of central flange 112 on the bolt member 102 and a second one. central rim configuration 114 on the case member 102. With reference to the bolt member 102, the inlet threads 120 extend from the tip of the bolt 116 to the full height threads 122. The outlet threads 124 extend from the full height threads 122 to the central flange seal 112. The inlet threads 126 extend from the center ridge seal 112 to the full height threads 128. The exit threads 130 extend from the full height threads 128 to the base 132 of the bolt member 102. With respect to the box member 106, the exit threads 140 extend from the base of the box 134 to the full height threads 142. The entry threads 144 extend from the full height threads 142 to the seal of the central rim 114. The exit threads 126 they extend from the center rim seal 114 to the full height threads 148. The inlet threads 150 extend from the full height threads 148 to the tip of the pin 136. As shown in Figure 8, after assembly of the connection 100, the output threads 124 engage the inlet threads 144, the full height threads 122, 142 are interengaged, and the inlet threads 120 engage the outfeed threads 140. In addition, the outfeed threads 146 are coupled to the inlet threads 126, the full height threads 128, 148 are interengaged, and the inlet threads 150 are interengaged with the outlet threads 130. The connection-of the? 315 patent uses variable width threads for allow pull the insertion of the threads into the adjustment slots. The square threads or quasi-square threads described above with respect to FIGS. 1-13 are used in connection 100. As distinguished from the embodiments shown in FIGS. 1-13, connection 100 moves the immobilization without engagement of the coupling. tip of the bolt against the base of the box. In mounting the connection 100, additional mounting torque is applied to the connection after the configuration of the seal of the central flange is established between the seals of the central flange 112, 114. This additional torque increases the tension in the box member 106 between the seal of the central rim 114 and the tip of the case 136 and increases the tension in the bolt member 102 between the seal of the central rim 112 and the tip of the bolt 116. That portion of the bolt member 102 extending from the seal of the central flange 112 to the tip of the bolt 116 is a thin member, particularly in comparison with that portion of the box extending from the seal of the central flange 114 to the base of the box 134. In addition, that portion of the member of box extending from the seal of the central rim 114 to the tip of the box 136 is also a thin member particularly compared to that portion of the bolt member that extends from the seal of the central flange 112 to the base of the bolt 132. When the connection 100 is assembled, the thin and thick sections of the bolt member 102 place in comparison and the thin and thick sections or portions of the case member 106 are place in tension. This increases the adjustment pressures between the load flanks. The Poisson effect on the thin portions of the bolt and the box members 102, 106, respectively, close the spaces between the load flanks. Also when the thin sections of the bolt and box members are placed in compression and the thick sections of the bolt and box members are placed under tension, the Poisson effect causes the threads to be immobilized in a manner similar to that shown in the drawings. embodiments of Figures 1-13. The locking of the thread occurs because the spaces are small and the radial interferences are small so that when the central flange engages, the tension of the box and pin members 106, 102 is increased thereby amplifying the effect of Poisson The deep incrustation on the box member 106 and the small advance on the bolt member 102 are the thin members. This ratio of thickness between the larger rungs and the smaller rungs of the corresponding bolt and box members 102, 106 results in the locking of the threads. The profile of the thread of the present invention can be used in two different types of central flange seal connections, namely an altered hot forged connection and a cold-drawn flat end pipe (pipe). It can also be used in a cold formed tube, stamping, cold stamping to connect casing pipes. Although a preferred embodiment of the invention has been shown and described, modifications can be made by those skilled in the art without departing from the spirit of the invention.

Claims (48)

2. Having described the invention as above, the content of the following claims is claimed as property. A tubular connection, characterized in that it comprises: a bolt member having external inclined threads; a box member having internal inclined threads; the external and internal inclined threads are square or almost square threads having flanks of attack or insertion and load flanks with thread grooves between the threads; the attack or insertion flanks have bevels at the corners which engage after the bolt member is inserted in the box member; and the corner bevels guide the threads into the grooves of the thread after the relative rotation of the bolt and box members. The tubular connection according to claim 1, characterized in that the bolt and box members each include a tip and a base.
3. 3. The tubular connection according to claim 2, characterized in that the threads are sequentially immobilized from the tip of the bolt to the base of the bolt.
4. The tubular connection according to claim 2, characterized in that the bolt and box members include cylindrical surfaces that interfere forming a metal-to-metal seal.
5. 5. The tubular connection according to claim 2, characterized in that the tip of the bolt and the base of the box are coupled to form a torsion flange.
6. The tubular connection according to claim 5, characterized in that the tip of the bolt includes a first flange and the base of the box includes a second flange, the first and second flange engage to form the torsion flange.
7. The tubular connection according to claim 2, characterized in that the pin point and the base of the box are coupled to form a metal-to-metal seal.
8. The tubular connection according to claim 7, characterized in that the bolt tip includes a first annular member and a bolt groove, the base of the case includes a second annular member and a box groove, the first annular member is received by the slot of the box and the second annular member is received by the slot of the pin.
9. The tubular connection according to claim 8, characterized in that the first annular member is received in the slot of the box and the second annular member is received in the slot of the pin to form a torsion flange.
10. The tubular connection according to claim 7, characterized in that the first annular member includes a first cylindrical surface and a first frustoconical surface, the second annular member forms a second cylindrical surface and a second frustoconical surface, the first and second cylindrical surfaces. and the first and second frustoconical surfaces are engaged in a seal fashion to form a seal.
11. The tubular connection according to claim 1, characterized in that the load flanks have a negative flank angle and the attack or insert flanks have a positive flank angle that is greater than the negative flank angle.
12. 12. The tubular connection according to claim 11, characterized in that the negative flank angle is between 0 and 6.5 ° and the positive flank angle is between 0 and 7.5 °.
13. 13. The tubular connection according to claim 1, characterized in that the load flanks have a positive flank angle and the attack or insertion flanks have a negative flank angle that is greater than the positive flank angle.
14. The tubular connection according to claim 1, characterized in that the threads have a width which is at least 95% the width of the thread groove.
15. The tubular connection according to claim 1, characterized in that it further includes a space of at least 0.002 inches (0.00508 mm) between the load flanks after inserting the bolt member into the box member.
16. 16. The tubular connection in accordance with claim 1, characterized in that the threads have ridges and roots, the crests and roots have a radial interference in the range of 0.0010 to 0.0015 inches (0.00254 and 0.00381 mm) of the connection diameter.
17. 17. The tubular connection according to claim 1, characterized in that the threads have an increased width in the line of separation of the threads.
18. 18. The tubular connection according to claim 16, characterized in that the width forms a cam flank which brings the square threads towards the grooves of the threads after the relative rotation of the bolt and box members.
19. 19. The tubular connection according to claim 1, characterized in that the width puts the attack or insertion flanks together.
20. 20. The tubular connection according to claim 1, characterized in that the bolt member and the box member are placed on the ends of the tubular members, the bolt and box members form a tubular wall having a thickness of between 75 and 108% of the thickness of the tubular members.
21. 21. The tubular connection according to claim 1, characterized in that the inlet threads, the full height threads and the exit threads extend from a point to a base of the bolt and box members.
22. 22. A threaded pipe connection, characterized in that it comprises a box having internal inclined threads and a bolt having slanted external threads that engage the threads on the box when the connection is mounted, the threads on the box and the bolt have a load flank with a negative flank angle and flanks of attack or insertion with a positive flank angle that is greater than the angle of the negative flank of the load flanks but sufficient to guide the bolt towards the box, the flanks of attack or insertion is engaged when the bolt moves into the housing due to the relative rotation of the bolt and housing, the bolt has a point and the housing has a base that moves toward the coupling during rotational mounting that deflects the load of the bolts. flanks of attack or insertion to the load flanks after the rotational mounting of the threaded connection, the threads are sequentially immobilized from the tip of the bolt to the base of the bolt c When the connection is established completely. A tubular connection, characterized in that it comprises: a bolt member having external, inclined threads including inlet threads, full height threads, and outlet threads extending from a point to a base of the bolt member; a box member having inclined internal threads including exit threads, full height threads and inlet threads extending from a base to a tip of the box member; the threads include square or almost square threads and adjustment slots, the threads have ridges and roots and flanks of attack or insertion and load with the flanks of attack or insertion having bevels in the corners and an increased width in the lines of separation of the thread;
23. the widths form a cam flank extending from the bevel of the corner to the width and a second flank extending from the width to the root; the tip of the bolt engages the base of the box to form a seal assembly; A primary twist flange is formed by the tip of the bolt and the base of the box; the box member receives the bolt member until it engages the corner bevels; the corner bevels guide the flanks of attack or insertion of the threads towards the adjustment grooves and the cam flanks carry the flanks of attack or insertion until the coupling after the rotation of one of the bolt members or box in relation to the another member; the coupling of the flank of attack or insertion is diverted to a coupling of the load flanks when the seal assembly is formed; the tip of the bolt and the base of the box are immobilized when the primary torsion bead is formed; The threads are sequentially immobilized from the bolt tip to the base of the bolt when additional torque is applied to complete the fitting assembly.
24. 24. A method for mounting a tubular connection, characterized in that it comprises: inserting a threaded bolt member into a threaded box member; attach the corner bevels on the flanks of attack or insertion of the threads of the bolt and the box; form a space between the threads; rotating the bolt and box members in mutual relation; placing the threads on the bolt member and housing within the adjustment slots on the corresponding bolt member and housing; coupling the surfaces of the seal on the tip of the bolt member and a base of the ca-member; deflect the load of the flanks of attack or insertion in the load flanks on the threads; immobilize the surface of the seal; spin one member further in relation to the other member; and sequentially locking the threads from the back of the bolt tip to the base of the bolt member.
25. 25. The method according to claim 24, characterized in that it further includes centering the bolt member inside the box member.
26. 26. The method according to claim 24, characterized in that it further includes embedding the bolt member at least halfway to the box member before engagement of the corner bevels.
27. 27. The method according to claim 24, characterized in that it further includes coupling the leading or insertion flanks and not coupling the load flanks when the threads are guided towards the grooves.
28. 28. The method according to claim 24, characterized in that the coupling of the seal surfaces causes the charge to deviate from the attack or insertion flanks to the load flanks.
29. 29. The method according to claim 28, characterized in that the coupling of the load flanks drives the seal surfaces together.
30. 30. The method according to claim 24, characterized in that the tip of the bolt member is placed in compression in the base and the box member is placed in tension.
31. 31. The method according to claim 30, characterized in that the compression of the bolt member and the tension on the box member increases the contact between the load flanks.
32. 32. The method according to claim 30, characterized in that the compression of the bolt member and the tension on the box member causes the crests and roots on the threads to be engaged by interference.
33. 33. The method according to claim 24, characterized in that the surfaces of the seal are cylindrical surfaces on the bolt and box members.
34. 34. The method of compliance with the claim

    24, characterized in that it includes bringing the attack or insertion flanks together.
35. 35. The method according to claim 24, characterized in that it also includes coupling the load flanks, crests and roots of the threads and flanks of attack or insertion in the lines of separation.
36. 36. The method according to claim 35, characterized in that the crushing stress loads are evenly distributed along the length of the thread.
37. 37. The method according to claim 24, characterized in that the surfaces of the seal are isolated from the mounting torsion.
38. 38. The method according to claim 24, characterized in that it also includes increasing the resistance to torsion with the increase of the mounting torsion.
39. 39. The method according to claim 24, characterized in that the tip of the pin stops the rotation before the final assembly of the connection.
40. 40. The method according to claim 24, characterized in that it further includes transferring substantially all the remaining applied torque to the threads after locking the surfaces of the seal.
41. 41. The method according to the claim

    24, characterized in that it further includes forming primary torsion ridges between the bolt tip-and the base of the box.
42. 42. The method according to claim 41, characterized in that it further includes coupling the tip of the box and the base of the pin after the primary torsion bead is formed.
43. 43. A connection, characterized in that it comprises: a member having constant inclined threads with slots between them; each of the threads has a ridge, a root, a flank of attack or insertion and a flank of load; and the leading or insertion flank has at least first and second inclined surfaces.
44. 44. The connection according to claim 43, characterized in that the first inclination increases a space between adjacent threads.
45. 45. The connection according to claim 43, characterized in that the threads have a square or almost square profile.
46. 46. The connection according to claim 43, characterized in that it also includes a third inclination on the flank of attack or insertion.
47. 47. The connection according to claim 46, characterized in that the third inclination raises the threads towards the grooves.
48. 48. The connection according to claim 47, characterized in that the threads have a square or almost square profile.