Portable pipe tong and method of use

A relatively compact portable tong assembly utilizing adaptable jaws for gripping the threaded box and pin ends of adjacent pipe joints without the use of an external support and thus applying final make-up torque or applying initial breakout torque to threaded pipe joints using only a spanner, socket and ratchet or other such hand tools for quickly applying torque to at least one of the tong jaws. An integral means is also provided for accurately measuring the amount of torque being applied to the joints.

1. FIELD OF THE INVENTION

This invention relates generally to pipe tongs apparatus used to make and break pipe joint connections and more particularly to portable, manually operated wrenches using opposable jaws for gripping each pipe comprising a coupled pipe joint and applying torque to at least one of the opposable jaws while retaining the opposite jaw thus exerting a simultaneous multiplied mechanical force on the jaws thereby breaking the coupling apart or applying sufficient torque to seal the joint.

2. GENERAL BACKGROUND

Manually operated pipe wrenches and tongs have been used for many years for applying torque to a threaded pipe joint as is exhibited by U.S. Pat. Nos. 443,312, 2,540,553, 3,122,952, 3,752,016, 3,880,024, 4,305,316, 5,062,326 and 5,546,833. In each of these cases a pipe wrench of some type is secured to each of the coupled pipe members in a manner whereby one of the pipe wrenches may be manipulated to rotate one of the pipe members while the adjacent pipe member is retained. The long torque arms of the pipe wrenches provide a significant mechanical advantage. A threaded member used to exert force on the torque arms in a retracting or extending manner produces and even further advantage.

Looking at the prior art as a whole it becomes obvious that the mechanical pipe coupling tools although effective in most case were simply too large, slow and cumbersome for use in coupling and uncoupling oil field tubular members. It should be noted that there are several disadvantages such as; (i) the need to remove the apparatus from the pipe and reverse the procedure when changing from a make-up to a break-out procedure (ii) the lengthy torque arms, (iii) and the tendency of the pipe wrench jaws to mar the pipe surfaces. Therefore, the process evolved into faster hydraulically driven power tong units. However, recently the older mechanical pipe tongs are being resurrected for specialty operations where it is impractical or impossible to use power tongs as a result of their great bulk and need for a power supply. In such operations there is a need for a relatively fast manual tong unit, that is both compact and portable, is capable of producing a high torque on the pipe coupling without significant marring of the pipe and need not be physically reversed on the pipe when changing between break-out and make-up operations. There is also a need to readily determine the make-up torque applied to each joint.

3. SUMMARY OF THE INVENTION

The present invention teaches the use of a relatively compact portable tong assembly utilizing adaptable jaws for gripping the threaded box and pin ends of adjacent pipe joints without the use of an external support and thus applying final make-up torque or applying initial breakout torque to threaded pipe joints using only a spanner, socket and ratchet or other such hand tools for quickly applying torque to at least one of the tong jaws. An integral means is also provided for accurately measuring the amount of torque being applied to the joints.

5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As first seen inFIG. 1the light weight, portable, manual tong assembly10includes a base member including the torque actuator assembly12to which is attached an upper tong jaw assembly14and a lower pivotal tong jaw assembly16. Each of the jaw assemblies14,16and the tong torque actuator assembly includes actuator screw assemblies18,20,22, that are rotatable by a wrench which may include a ratchet and socket24, a spanner25or may be operated by a power tool such as an electric or air motor. The torque actuator assembly12further includes a load cell assembly26and torque pressure gauge28. The tong assembly10is self-supporting by being clamped onto the pipe string29.

As seen from the top inFIG. 2the upper tong jaw assembly14and lower tong jaw assemblies16better seen in cut-a-wayFIG. 3are constructed of light weight materials, both include a pair of opposing pipe dies30a,30bslidable within a channel for engaging the box and pin ends of the coupling32better seen inFIG. 4. One of the pipe dies30aretained by the jaws14and16seen inFIGS. 2 and 3is rotatably secured to the jack screw assemblies20,22, respectively in a manner whereby rotation of there respective screws traverses the jaws30athereby, engaging the pipe coupling32. The lower tong jaw16seen inFIG. 3is also transversely pivotal about the threaded lead screw pin34via the tong arm slot36located in the arm portion of the jaw assembly16.

The tong assembly10is positioned on the pipe coupling as seen inFIG. 4with each of the jaw assemblies14and16engaging the adjacent elements of the pipe coupling32prior to insertion of the cooperative dies30bretained in position by the ledges38located at the mouth of each of the jaw assemblies14and16. Jacking screw assemblies20and22are then actuated completing the clamping process. Loosing the screws allows the dies30bto be removed from the jaws14and16and removal from the pipe string29.

The distance X between the central axis of the pipe coupling32and the central axis of the pin assembly34seen inFIG. 3and the thickness of the tong jaws14,16may vary depending on the size of the coupling or as the application may require. Torque applied to the pipe coupling32by exerting rotary torque on the screw18is calculated as a result of known values of distance, thread progression and applied pressure on the load cell assemble26and expressed in foot pounds on the torque gauge28. Other methods of determining applied torque to the pipe joint may simple be a chart correlating applied torque on the load cell to that of calculated torque applied to the joint.

As further seen inFIG. 5the nomenclature of the afore mentioned portable tong assembly10is as follows; an elongated rectangular body member40that includes a head portion42which includes a longitudinal orifice43therein leading to a rectangular tang portion extending from the head portion and includes an elongated slotted portion44for slidable receiving a pin member34. The head portion further including both longitudinal apertures and transverse threaded holes for receiving threaded members56and82and is counter bored for receiving the load cell48. A lead screw18fitted with thrust bearings60located on each side of a shoulder50and threadably engaging the pin34. A housing52threadably attached to the load cell48retains the lead screw and bearings60in position relative to the body member40. The housing52further provides mounting and access to the load cell48for gauge member28.

Each of the jaw assemblies14and16include jack screw assemblies20and22that further include removable threaded sleeves64, screw member66, washer67and retainer pins68. It should be noted that the lower or pivotal tong jaw16includes an arm portion having a transverse channel84with each side of the channel having elongated slots36for straddling the tang portion of the base member40and capturing pin34being slidable within the slots44and36.

As further depicted inFIG. 6the dies30bare readily slidably inserted or removed. By first installing a die30binto the cavity62the jaw16and rotating the screw assembly22thus securing the tong to the pipe string29, rotating the lead screw assembly18then rotates the base member12about the axis of the pipe string thereby allowing the upper jaw to engage the pipe string29. Inserting the remaining die30band tightening the upper jaw14-screw assembly20completes the attachment procedure. Further tightening of the lead screw18applies torque to the lower jaw assembly16while retaining the upper jaw assembly14, thereby coupling or uncoupling the pipe joint.

The lead screw assembly and load cell assembly is further detailed in cross-section inFIG. 7. Here we see that the lead screw18is supported at the head end by thrust bearing60located within the housing52and threadably attached to the pin member34that is slidable within the slot44better seen inFIG. 8and further supported at the opposite end of the base member40by a bushing. Rotation of the lead screw brings one of the thrust bearings60into contact with the load cell48thereby applying pressure to the cell as an indication of the applied torque as read on the gauge28seen in previous figures.

As best seen inFIG. 8the screw assemblies utilize a threaded sleeve60removably threaded into the jaws14and16and the screw members66are threaded into the threaded sleeve60. A nipple70is provided at one end of the screw member66with a radial groove72therein for insertion into a corresponding hole in the dies30a. Retainer pins68inserted into the die30aintersecting the radial groove on the nipple70retain the die to the screw member66while still allowing rotation of the screw member66relative to the die30a.

Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in any limiting sense.