Tong assembly with swiveling trunnions

Abstract

A tong assembly for use in the make up or breakout of a threaded connection between adjacent tubulars in a tubular string includes jaws that engage the tubulars, handles for rotating the jaws, and a actuation assembly for exerting a force to the handles. The actuation assembly applies the force to the handles along a path intersecting the handles, which avoids creating torsion in the handles. The connection between the actuation assembly and the handles includes trunnion assemblies that swivel about ends of the handles to align the force with the handles.

Description

BACKGROUND OF THE INVENTION1. Field of Invention

[0001] The present disclosure relates to a tong assembly for makeup and / or breakout of a threaded pipe connection.2. Description of Prior Art

[0002] Tong assemblies are typically used for the makeup and breakout of pipe strings having multiple tubulars, such as those employed in the exploration and production of hydrocarbons. These tong assemblies generally include a pair of jaws that engage adjacent tubulars and handles attached to the jaws. Applying tangential forces to one of or both handles, either manually or from an automated source, rotates the jaws to either makeup or breakout the threaded connection between the adjacent tubulars. The forces required for the makeup or breakout jaws sometimes create resultant forces exceeding yield points in the jaws, handles, or attached linkage, which causes mechanical failure in one or more of these components. Failure of these components can be hazardous to operations personnel. Therefore, a need exists for reducing mechanical stresses in tong assemblies.SUMMARY OF THE INVENTION

[0003] Disclosed herein is an example of a tong assembly for relative rotation of tubulars, which includes a first tong member rotationally engaged with a first tubular, a second tong member rotationally engaged with a second tubular that is threaded to the first tubular, an actuation assembly coupled between first and second handles of the first and second tong members respectively, so that when the actuation assembly is operated, a force is applied from the actuation assembly to the first and second tong members that creates oppositely directed torques in the first and second tubulars, and couplings pivotingly mounted on the first and second handles, so that a path of the force intersects axes of the first and second handles with relative movement of the first and second handles. In examples, the force extends axially along the actuation assembly, and the coupling is intersected by a path of the force extending along the actuation assembly. In an embodiment, an axis of the actuation assembly intersects axes of the first and second handles, and alternatively, rotation in a first direction makes up a threaded connection between the tubulars, and rotation in a second direction opposite the first direction causes break out of the threaded connection. In another embodiment, rotational engagement of the first tong member with the first tubular is by a first jaw assembly that is included with the first tong member, and the first handle is pinned to the first jaw assembly. In an alternative, rotational engagement of the second tong member with the second tubular is by a second jaw assembly that is included with the second tong member, where the second handle is pinned to the second jaw assembly. In an embodiment, the actuation assembly includes a hydraulic cylinder and a cylinder rod, and when the actuation assembly is operated, the cylinder rod selectively projects from an end of the hydraulic cylinder, and optionally the couplings are trunnion mounts with axial bores that receive posts formed on ends of the first and second handles and tang like projections that attach to clevis like fittings coupled to opposing ends of the hydraulic cylinder. In another embodiment, the actuation assembly includes a bolt threadingly engaged with one of the couplings, so that rotation of the bolt in one direction creates a force in the bolt that draws the first and second handles together and rotation of the bolt in an opposite direction creates a force in the bolt that moves the first and second handles apart, and where the coupling mounted on the first handle includes a trunnion mount that pivotingly mounts onto a post on an upper end of the first handle, a trunnion nut with a threaded bore that receives the bolt, posts on opposing lateral sides of the trunnion nut that extend into receptacles formed in side walls of the trunnion mount, and alternatively an end of the bolt inserts into a trunnion body that is mounted onto an end of the second handle, and where the bolt is retained in the trunnion body with a shear pin, and wherein an axial force in the bolt that causes a failure of the bolt exceeds an axial force in the bolt that causes fracture of the shear pin.

[0004] Also disclosed is an example of a method of rotating tubulars attached by a threaded connection, which includes engaging a first tubular with a first jaw assembly of a tong assembly, engaging a second tubular with a second jaw assembly of a tong assembly, exerting a first torque in the first tubular and a second torque in the second tubular by applying a force between a first and second handle of the tong assembly, and minimizing torsion in the first and second handles by maintaining a direction of the force to be along a path that intersects an axis of the first handle and an axis of the second handle. Examples exist in which maintaining a direction of the force to be along a path that intersects an axis of the first handle and an axis of the second handle includes forming pivoting couplings between a source of the applied force and ends of the first and second handles. The source of the applied force in one example is a threaded bolt that engages a threaded trunnion mounted on an end of one of the handles, in alternatives of which an amount of force applied to the tong assembly from the bolt 14 is limited by adding a shear pin at a connection between the bolt and an end of another one of the handles. In another example, the source of the applied force is a hydraulic cylinder and cylinder rod, and the force is generated by projecting the cylinder rod from the hydraulic cylinder. Examples of the pivoting couplings include posts that extend axially from the first and second handles, and trunnion mounts that land on and pivot about the posts.BRIEF DESCRIPTION OF DRAWINGS

[0005] Some of the features and benefits of the present invention having been stated, others will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:

[0006] FIG. 1 is a side elevational view of an example of a tong assembly in accordance with the present disclosure.

[0007] FIG. 2 is an exploded perspective view of the tong assembly of FIG. 1.

[0008] FIG. 3 is an end view of the tong assembly of FIG. 1.

[0009] FIG. 4 is a side elevational view of an alternate example of a tong assembly in accordance with the present disclosure.

[0010] FIG. 5 is an exploded perspective view of the tong assembly of FIG. 4.

[0011] FIG. 6 is an end view of the tong assembly of FIG. 4.

[0012] FIG. 7 is a side sectional view of a portion of the example tong assembly of FIG. 4 having a trunnion assembly.

[0013] While subject matter is described in connection with embodiments disclosed herein, it will be understood that the scope of the present disclosure is not limited to any particular embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents thereof.DETAILED DESCRIPTION OF INVENTION

[0014] The method and system of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings in which embodiments are shown. The method and system of the present disclosure may be in many different forms and should not be construed as limited to the illustrated embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Like numbers refer to like elements throughout. In an embodiment, usage of the term “about” includes + / −5% of a cited magnitude. In an embodiment, the term “substantially” includes + / −5% of a cited magnitude, comparison, or description. In an embodiment, usage of the term “generally” includes + / −10% of a cited magnitude.

[0015] It is to be further understood that the scope of the present disclosure is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. In the drawings and specification, there have been disclosed illustrative embodiments and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation.

[0016] Shown in a side elevational view in FIG. 1 is an example of a tong assembly 10, which is used for the makeup or breakout of a connection 12 between adjacent tubular sections 141, 142 that make up a tubular string 16. Threads 181,2 are shown in dashed outline, which are included on ends of the sections 141,2, Engaging the threads 181,2 and rotating sections 141,2, relative to one another forms connection 12 to make up tubular string 16, and breakout of tubular string 16 occurs by rotating sections 141,2, relative to one another in an opposite direction, which disengages the threads 181,2. Tong assembly 10 is shown having a pair of tong members 201,2 that each have a jaw assembly 221,2, which is the portion of the tong assembly 10 that engages the sections 141,2 of tubular string 16. A handle 241,2 is included with each of the tong members 201,2, each of which is elongated and has an end pinned to the jaw assemblies 221,2. Urging free ends of handles 241,2 towards or away from one another, engages jaw assemblies 221,2 with the sections 141,2, and also rotates jaw assemblies 221,2 about axis A16 of the tubular string 16 to create torque t1, t2 in the sections 141,2 for the makeup and breakout of the tubular string 16. An example of an actuation assembly 26 is shown coupled between handles 241,2, which selectively exerts a force F26 between handles 241,2, which is what generates the initiation of torque t1, t2. A hydraulic cylinder 28 is included with the actuation assembly 26 and shown having a rearward end 30 engaged with a free end of handle 241 by a coupling 321. A clevis 34 on an opposite end of actuation assembly 26 engages coupling 322 on a free end of handle 242. Couplings 321, 322 of the illustrated example each include trunnion mounts 331, 332. Clevis 34 attaches to cylinder 28 via an elongated cylinder rod 36, which in response to the flow of hydraulic fluid (not shown inside) inside cylinder 28, selectively reciprocates cylinder rod 36 with respect to cylinder 28 into create force F26 that is exerted onto handles 241,2. As explained in more detail below, an advantage of the tong assembly 10 disclosed herein is that the trunnion mounts 331,2 on the three ends of handle's 241,2 are intersected by the axes A241,2 of the handles 241,2 and pivot about those axes A241,2. Moreover, irrespective of movement of either handle 241,2, the trunnion mounts 331,2 continue to be intersected by these axes A241,2. Additionally, as the trunnion mounts 331,2 pivot about axes A241,2 the force F26 also intersects or is generally aligned with axes A241,2. Aligning the forces exerted onto or by handles 241,2 with the axes A241,2 avoids eccentric loading on the handles 241,2, which prevents torsion in the handles 241,2 and reduces a probability of failure in components of the tong assembly 10.

[0017] In FIG. 2 tong assembly 10 is shown in a perspective partially exploded view. For the purposes of discussion herein, included in FIG. 2 is an X-Y-Z Cartesian coordinate axis, which is provided to illustrate spatial relationships between the various components of the tong assembly 10. In a non-limiting example, “rearward” and “forward” generally refer to spacing in a direction along or parallel with axis AY, “lateral” and “transverse” generally refers to spacing in a direction along or parallel with axis AX, and “vertical”, “above”, and “below” generally refer to spacing in a direction along or parallel with axis AZ. As jaw assembly 221 is shown exploded and jaw assembly 222 depicted intact, the following explanation of jaw assembly 221 also provides a description of counterpart components in jaw assembly 222. Jaw assembly 221 includes a main jaw 381, which is shown as an elongated curved member having a slot 401 formed axially through an end portion to form a pair of planar extensions. Transverse to slot 401 are apertures 421 that intersect slot 401 and planar extensions. When assembled, the apertures 421 register with an aperture 441 formed transverse through an end of handle 241 profiled to have a reduced thickness, and a pin 461 extends through the registered apertures 421, 441 to provide a pinned connection between handle 241 and main jaw 381. An optional retaining ring 471 mounts onto an end of pin 461 to retain pin 461 in the apertures 421, 441. On a concave surface of the main jaw 381 are inserts 481, which optionally have teeth formed on an outer facing surface for gripping the outer surfaces of the sections 141, 2 of tubular string 16 (FIG. 1). Jaw assembly 221 also includes a hook jaw 501, which similar to the main jaw 381, has an end with an axial slot 521 that is intersected by aperture 541. An end of main jaw 381 opposite slot 401 is profiled to have a reduced width, which when assembled is inserted into the slot 521 to register an aperture 561 on the profiled end of main jaw 381 with aperture 541, a pin 581 inserts through the registered apertures 541, 561 to retain main jaw 381 to hook jaw 501 and an optional retaining ring 591 is selectively mounted onto an end of pin 58 to keep pin within the apertures 541, 561. An aperture 601 is formed transversely through an end of the hook jaw 501 opposite slot 521, which is profiled to have a reduced thickness. Jaw assembly 221 further includes a link assembly 621, which provides a pinned connection of jaws 381, 501 to handle 241. Link assembly 621, includes a pair of planar link plates 641, 661, which have a generally elliptical outer shape and with tabs 681, 701 that project downward from a lower edge each of the plates 641, 661. Apertures 721, 741 extend transversely through the plate 641 on opposite ends, and when assembled register with apertures 761, 781 formed on opposing ends of plate 661. Apertures 801, 821 extend through the tab 681, 701. Pin 831 inserts into apertures 801, 821, and optional snap rings 851 retain pin 831 to plates 741, 761. Hook jaw 501 is mounted onto handle 241 by registered apertures 601, 721, 761, registering apertures 741, 781 on opposing ends of an aperture 841 shown formed on an end of handle 241 and spaced rearward from aperture 441, inserting pin 861 through registered apertures 601, 721, 761, Retaining ring 871 is optionally included for retaining pin 861 to plates 741, 761. Mounting hook jaw 501 onto handle 241 further includes inserting pin 881 through registered apertures 741, 781, 841.

[0018] Still referring to FIG. 2, trunnion mount 331 is shown made up of a block-like trunnion body 891 which has an axial bore 901 that selectively receives a post 921 shown projecting axially upward from a free end of handle 241. As illustrated by curved arrow AP1, the block trunnion body 891 pivots about post 921 and about axis A241. An optional retaining ring 941 is shown which circumscribes an upper end of post 921 and extends partially into the side wall of bore 901 to help retain trunnion mount 331 to handle 241. A projection 951 has shown extending from a rearward side of the trunnion body 891, which is a generally planar member, an aperture 961 is formed through projection 951 in a directly generally transverse to axis A241. Rearward end 30 of cylinder 26 includes a clevis type arrangement having spaced apart planar members with an aperture 98 formed through each, similar to aperture 961, apertures 98 are generally transverse to axis A241. Registering aperture 961 with apertures 98 and inserting pin 100 through the registered apertures 961, 98 pivotingly secures the actuation assembly 26 to the trunnion mount 331, and in turn couples actuation assembly 26 with the handle 241. On the opposite end of actuation assembly 24 is clevis 34 shown with apertures 102 formed laterally through its prongs, registering apertures 102 with aperture 962 on the projection 952 of coupling 322 and inserting pin 104 through the registered apertures 962,102 couples the forward end of the actuation assembly 26 to the second handle 242. Optionally, pins 100, 104 are quick release pins. An optional coiled spring pin 106 is shown inserted into an aperture axially formed into a collar on a rearward side clevis 34. Pin 106 intersects a forward end of cylinder rod 36, pin 106 fractures at a load less than loads causing failure of any other components in the tong assembly 10, and is a frangible link that protects against injury to operations personnel. Further illustrated is curved arrow AP2 illustrating example pivoting movement of trunnion mount 332 with respect to axis A242 of handle 242. As such, the pivoting ability of the trunnion mounts 331,2 maintains intersection of force F26 (FIG. 1) and axes A241,2 to avoid torsion in the handles 241,2.

[0019] Shown in FIG. 3 is an elevational rearward view of an example of the tong assembly 10 that includes arrow At141 that represents torque exerted onto section 141 by tong member 201 in a first direction, and arrow At142 that is an opposite rotational direction and represents torque exerted onto section 142 by tong member 202. In a non-limiting example of operation, threaded connection between the sections 141,2 is being created or removed for make up or breakout of tubular string 16. Further illustrated in FIG. 3 is intersection of the force F26 exerted by the actuation assembly 26 (FIG. 1) onto the handles 241,2 and that this force F26 intersects both axes A241,2. In alternate embodiments force F26 intersects handles 241,2 at locations spaced laterally away from one or both axes A241,2, advantages of the present disclosure are still realized as the offset position of the path of the force F26 is not distal from either of the axes A241,2 so that torsion in the handles 241,2 does not create failure loads in the tong assembly 10.

[0020] Illustrated in FIGS. 4-7 is an alternate example of a tong assembly 110, which in a perspective elevational view in FIG. 6 is shown in a non-limiting example for use in the breakout or makeup of a threaded connection 112 between a pair of adjacent tubulars 1141,2 in a tubular string 116. Referring back to FIG. 4, shown is that tong assembly 110 includes first and second tong members 1201,2, that each include jaw assemblies 1221,2, attached elongate handles 1241,2 that receive a force F126 from an actuation assembly 126. In the example of FIG. 4, actuation assembly 126 includes an elongated bolt 128 having threads 130 formed along its outer surface and which extend between couplings 1321,2 that mount respectively on free ends of the handles 1241,2. In the example of FIG. 4, the couplings 1321,2 include trunnion assemblies 1331,2. Bolt head 134 is provided on an end of bolt 128 distal from its engagement with coupling 1322. Similar to tong assembly 10 of FIG. 1, an advantage of tong assembly 110 is that the trunnion assemblies 1331,2 pivot about handles 1241,2 so that force F126 intersects the axes A1241,2 of handles 1241,2, or at least a portion of handles 1241,2, to prevent torsion in handles 1241,2, represented by arrows AR1,2 that can create damaging effects on the handles 1241,2. Further illustrated in FIG. 4 is the oppositely directed torques t1,2 applied to the different sections 1141,2 in an example of operation using tong assembly 110 to make up or breakout tubing string 116. In examples, tong assembly 10 of FIG. 1 and tong assembly 110 are employed such that axis A116 of tubular string 116 is oriented vertically, as well as horizontally. Further in the example of FIG. 4 is that included with actuation assembly 126 is an annular cover 136 that circumscribes a portion of the bolt 128 between the couplings 1321,2. Cover 136 shields a portion of the threads on the bolt 128 from impacts, that without cover 136 would deform and damage the threads. An optional handle 137 shown as a U-shaped member has opposing ends mounted at distal portions of the cover 136. Grappling handle 137 by hand or mechanical attachment provides lifting and / or positioning capabilities of tong assembly 10.

[0021] Referring now to FIG. 5, an example of tong assembly 110 is shown in a perspective partially exploded view, and which includes a tong member 1201 with a jaw assembly 1221. For the purposes of discussion herein, included in FIG. 5 is an X-Y-X Cartesian coordinate axis, which is provided to illustrate spatial relationships between the various components of the tong assembly 10. In a non-limiting example, “rearward” and “forward” generally refer to spacing in a direction along or parallel with axis AY, “lateral” and “transverse” generally refer to spacing in a direction along or parallel with axis AX, and “vertical”, “above”, and “below” generally refer to spacing in a direction along or parallel with axis AZ. Similar to jaw assemblies 221, 2 of tong assembly 10 discussed above with regard to FIGS. 1-3, jaw assemblies 1221, 2 have largely the same components; and for the purposes of brevity, the following discussion of jaw assembly 1221 and its components is intended to provide an explanation of jaw assembly 1222. Jaw assembly 1221 has a curved main jaw 1381 with a slot 1401 on one end, an aperture 142 intersecting slot 1401, a transverse slot 1441 through a lower end of the handle 1241, a hinge pin 1461 that intersects apertures 1401, 1441, and an optional ring 1471 for maintaining pin 1461 in place. Inserts 1481 are shown mounted on the concave surface of the main jaw 1381, and a hook jaw 1501 has a slot 1521 formed on one end of its curved body, apertures 1541 on this end are transverse to and intersect the slot 1521 An end of the main jaw 1381 opposite slot 1401 is profiled to have a reduced width, an aperture 1561 is formed transversely through the profiled portion. A step of assembly includes registering apertures 1541, 1561 and inserting a pin 1581 through the registered apertures 1541, 1561. An optional ring 1591 is used to hold pin 1581 in apertures 1541, 1561. Hook jaw 1501 includes a transverse aperture 1601 on a reduced width portion disposed opposite the slot 1521. A link assembly 1621 is shown, which includes a pair of elliptically shaped link plates 1641, 1661 having tabs 1681, 1701 that respectively project downward from their lower edges. Link assembly 1621 couples jaws 1381, 1501 to handle 1241. Apertures 1721, 1741 are formed transversely through plate 1641, and apertures 1761, 1781 are formed transversely through plate 1661. Apertures 1801, 182 project transversely through the tabs 1681, 1701 on plates 1641, 1661. In an example of assembly, plates 1641, 1661 are positioned on opposing sides of handle 1241 and with aperture 1741 and aperture 1781 registered with an aperture 1841 formed on a lower end of handle 1241. A pin 1861 inserts through the registered apertures 1741, 1781, 1841 to pin the link assembly 1621 to the handle 1241. The hook jaw 1501 is engaged to the link assembly 1621 by registering apertures 1721, 1761 with aperture 1601 and inserting pin 1801 through the registered apertures 1721, 1761. A pin 1901 inserts through apertures 1801, 1821 and snap rings 1901 on opposing ends of pin 1901 retain pin 1901 to plates 1641, 1661.

[0022] Still referring to FIG. 5, a cylindrically shaped post 1921 is shown projecting axially from an upper end of handle 1241 on which coupling 1321 is pivotingly mounted. An optional retaining ring 1941 is shown, which mounts onto post 1921 and for retaining the coupling 1321 onto the handle 1241. Included with coupling 1321 is a trunnion assembly 1331 that is made up of a block-like trunnion body 1961 shown having post 1981, 2001 projecting outward from opposing lateral surfaces of the trunnion body 1961. A bore 2021 is formed lengthwise through the trunnion body 1961 and oriented generally transverse to the posts 1981, 2001. In the example shown, forward, rearward, and lateral surfaces of trunnion body 1961 are generally planar, and upper and lower surfaces are concave with an apex roughly coinciding with a midpoint of trunnion body 1961. Trunnion assembly 1331 further includes a trunnion section 2061, which has a vertically oriented planar portion with a receptacle 2071 formed transversely through the planar portion. Trunnion assembly 1331 further includes another trunnion section 2081 that is a mirror image of trunnion section 2061 also having a planar vertical portion with a transverse receptacle 2091. Sections 2061, 2081 each include base portions 2101, 2121 on lower ends of the planar portions having widths greater than the planar vertical portions. Semicircular recesses 2141, 2161 are formed in the base portions 2101, 2121. When sections 2061, 2081 are mated (FIG. 6), outer edges of the base portions 2101, 2121 are brought into abutting contact to adjoin the recesses 2141, 2161, which forms an opening vertically through base portions 2101, 2121 that is complementary to post 1921. The circular profiles of post 1921 and opening allow for pivoting of trunnion assembly 1331 about post 1921 and handle 1241. Sections 2061, 2081 are engaged by inserting cap screws 2181, 2201 into holes 2221 formed transversely through a base portions 2101, 2121 and tightening the cap screws 2181, 2201.

[0023] Referring now to FIGS. 5 and 7, shown is engagement between coupling 1322 and an end of bolt 128 opposite bolt head 134. A shown, the end of bolt 128 projects into a bore 2022 formed lengthwise through trunnion body 1962. In the example of FIG. 7 bore 202 is smooth and without threads, alternatives exist in which bore 202 includes threads. A rearward portion of bore 202 has an enlarged diameter in which an annular collar 224 is inserted and that circumscribes a terminal end of bolt 128. A shear pin 226 axially intersects collar 224 and bolt 128. The shear pin 226 is configured to fail at a force that is less than a point at which bolt 128 experiences failure so that potential injury to operations personnel is avoided. Examples of shear pin 226 include a solid elongated cylindrical member, a spiral spring pin, a split spring pin, and combinations. Further shown is that the base portion 2122, with its recess 2162 receives post 1922 to allow pivoting of the coupling 1322, to maintain the path of the force along bolt 128 so that intersection with axis A1242 is maintained. An annular retaining ring 228 is shown in the forward end of bore 2022, which fits into a recess formed along an inner surface of bore 2022 to interfere with movement of collar 224 axially from within bore 2022.

[0024] In a non-limiting example of use of tong assembly 10 of FIGS. 1-3, breakout of a tubular string 16 is performed by engaging section 141 of string 16 with jaw assembly 221 and engaging section 142 with jaw assembly 222. Actuation assembly 26 is operated by directing hydraulic fluid from a hydraulic fluid source (not shown) to cylinder 28 causing cylinder rod 36 to extend forward from cylinder 28 and generate force F26. Upper ends of handles 241,2 are urged away from one another in response to application of force F26, which by virtue of the pinned connection to jaw assemblies 221,2 by the link assemblies 621,2, causes jaw assemblies 221,2 to rotate in directions opposite from one another, that in turn rotates sections 141,2 in opposite directions to decouple or break threaded connection 12 (FIG. 1). The pivoting action of couplings 321,2 with respect to handles 201,2 aligns a path of force F26 to intersect with axes A241,2, which like handles 241,2 are laterally offset from one another. Moreover, the pivoting of the couplings 321,2 maintains intersecting alignment as the handles 241,2 are urged farther away from one another by the actuation assembly 26.

[0025] In a non-limiting example of use of tong assembly 110 of FIGS. 4-7, breakout of a tubular string 116 is performed by engaging section 1141 of string 116 with jaw assembly 1221 and engaging section 1142 with jaw assembly 1222. Actuation assembly 126 is operated by rotating bolt 128, such as by engaging bolt head 134 with a wrench (not shown) or other fitting and rotating the fitting (either manually or with a powered device). Threads 130 on both interact with threads inside bore 202 to generate force F126 (FIG. 4). Upper ends of handles 1241,2 are pivoted away from one another in response to application of force F126, which by virtue of the pinned connection to jaw assemblies 1221,2 by the link assemblies 1621,2, causes jaw assemblies 1221,2 to rotate in directions opposite from one another, that in turn rotates sections 1141,2 in opposite directions to decouple or break threaded connection 112 (FIG. 6). The pivoting action of couplings 1321,2 and trunnion mounts 1331,2 with respect to handles 1201,2 aligns a path of force F126 to intersect with axes A1241,2, which like handles 1241,2 are laterally offset from one another. Moreover, the pivoting of the couplings 1321,2 maintains intersecting alignment as the handles 241,2 are urged farther away from one another by the actuation assembly 26. The minimum offset distance between handles 1201,2 is dictated by an axial length of cover 136, as a rearward end of cover 136 provides a back stop that interferes with further forward travel of trunnion body 1961 along bolt 128. In a non-limiting example, an axial length of cover 136 is dimensioned based on a designated minimum distance between handles 1201,2.

[0026] The present invention described herein, therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned, as well as others inherent therein. While one or more embodiments have been given for purposes of disclosure, numerous changes exist in the details of procedures for accomplishing the desired results. These are intended to be encompassed within the spirit of the present invention disclosed herein and the scope of the appended claims.

Claims

1. A tong assembly for relative rotation of tubulars comprising:a first tong member rotationally engaged with a first tubular;a second tong member rotationally engaged with a second tubular that is threaded to the first tubular;an actuation assembly coupled between first and second handles of the first and second tong members respectively, so that when the actuation assembly is operated, a force is applied from the actuation assembly to the first and second tong members that creates oppositely directed torques in the first and second tubulars; andcouplings pivotingly mounted on the first and second handles, so that a path of the force intersects axes of the first and second handles with relative movement of the first and second handles.

2. The tong assembly of claim 1, wherein the force extends axially along the actuation assembly, and wherein the coupling is intersected by a path of the force extending along the actuation assembly.

3. The tong assembly of claim 1, wherein an axis of the actuation assembly intersects axes of the first and second handles.

4. The tong assembly of claim 1, wherein rotation in a first direction makes up a threaded connection between the tubulars, and wherein rotation in a second direction opposite the first direction causes break out of the threaded connection.

5. The tong assembly of claim 1, wherein rotational engagement of the first tong member with the first tubular is by a first jaw assembly that is included with the first tong member, wherein the first handle is pinned to the first jaw assembly.

6. The tong assembly of claim 1, wherein rotational engagement of the second tong member with the second tubular is by a second jaw assembly that is included with the second tong member, wherein the second handle is pinned to the second jaw assembly.

7. The tong assembly of claim 1, wherein the actuation assembly comprises a hydraulic cylinder and a cylinder rod, wherein when the actuation assembly is operated, the cylinder rod selectively projects from an end of the hydraulic cylinder,8. The tong assembly of claim 7, wherein the couplings comprise trunnion mounts with axial bores that receive posts formed on ends of the first and second handles and tang like projections that attach to clevis like fittings coupled to opposing ends of the hydraulic cylinder.

9. The tong assembly of claim 1, wherein the actuation assembly comprises a bolt threadingly engaged with one of the couplings, so that rotation of the bolt in one direction creates a force in the bolt that draws the first and second handles together and rotation of the bolt in an opposite direction creates a force in the bolt that moves the first and second handles apart.

10. The tong assembly of claim 9, wherein the coupling mounted on the first handle comprises a trunnion mount that pivotingly mounts onto a post on an upper end of the first handle, a trunnion nut with a threaded bore that receives the bolt, posts on opposing lateral sides of the trunnion nut that extend into receptacles formed in side walls of the trunnion mount.

11. The tong assembly of claim 10, wherein an end of the bolt inserts into a trunnion body that is mounted onto an end of the second handle, and wherein the bolt is retained in the trunnion body with a shear pin, and wherein an axial force in the bolt that causes a failure of the bolt exceeds an axial force in the bolt that causes fracture of the shear pin.

12. A method of rotating tubulars attached by a threaded connection, the method comprising:engaging a first tubular with a first jaw assembly of a tong assembly;engaging a second tubular with a second jaw assembly of a tong assembly;exerting a first torque in the first tubular and a second torque in the second tubular by applying a force between a first and second handle of the tong assembly; andminimizing torsion in the first and second handles by maintaining a direction of the force to be along a path that intersects an axis of the first handle and an axis of the second handle.

13. The method of claim 12, wherein maintaining a direction of the force to be along a path that intersects an axis of the first handle and an axis of the second handle comprises forming pivoting couplings between a source of the applied force and ends of the first and second handles.

14. The method of claim 13, wherein the source of the applied force comprises a threaded bolt that engages a threaded trunnion mounted on an end of one of the handles.

15. The method of claim 14, further comprising limiting an amount of force applied to the tong assembly from the bolt by adding a shear pin at a connection between the bolt and an end of another one of the handles.

16. The method of claim 13, wherein the source of the applied force comprises a hydraulic cylinder and cylinder rod, and wherein the force is generated by projecting the cylinder rod from the hydraulic cylinder.

17. The method of claim 13, wherein the pivoting couplings comprise posts that extend axially from the first and second handles, and trunnion mounts that land on and pivot about the posts.

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