Patent Abstract:
A self-adjusting spinner is provided that is capable of accommodating various pipe sizes without requiring the need for an operator to climb up the support mechanism and manually change the position of the drive assembly. The self-adjusting spinner includes a case having two pivotally connected members: a stationary case member and a moving case member. Upper and lower plates having gear racks are mounted on the stationary case member for moving a drive assembly horizontally across the case. The drive assembly includes a motor that drives gear sprocket through a drive shaft. The drive sprocket then drives a chain that rotates a drill pipe in an operative position relative to the case. The spinner also includes an adjusting assembly mounted on the case that moves the drive assembly along the gear rack upon the actuation of an adjustment sequence. When the adjustment sequence is initiated, the effective length of the chain is adjusted to accommodate drill pipes of varying diameters.

Full Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority of U.S. Provisional Application No. 61/059,673, filed on Jun. 6, 2008, titled SELF-ADJUSTING PIPE SPINNER, which application is incorporated in its entirety by reference in this application. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally concerns tooling and equipment utilized in the maintenance and servicing of oil and gas production wells, and more particularly relates to a power tong of the type utilized in conjunction with back-up tongs or wrenches to make or break threaded joints between successive tubing elements that extending through a well bore into underground deposits. 
         [0004]    2. Related Art 
         [0005]    In drilling for oil and gas, it is necessary to assemble a suing of drill pipe joints. Thus, a tubular drill string may be formed from a series of connected lengths of drill pipe and suspended by an overhead derrick. These lengths of drill pipe are connected by tapered external threads (the pin) on one end of the pipe, and tapered internal threads (the box) on the other end of the pipe. 
         [0006]    During the drilling and completion of a well, as the well is drilled deeper, additional joints of pipe are periodically added to the drill string and, as the drill bit at the end of the drill string is worn, the drill string must occasionally be pulled from the well and reinstalled for maintenance purposes. The process of pulling or installing the drill string is referred to as “tripping.” During tripping, the threaded connections between the lengths of drill pipe are connected and disconnected as needed. The connecting and disconnecting of adjacent sections of drill pipe (referred to as making or breaking the connection, respectively), involves applying torque to the connection and rotating one of the pipes relative to the other to fully engage or disengage the threads. 
         [0007]    In modern wells, a drill string may be thousands of feet long and typically is formed from individual thirty-foot sections of drill pipe. Even if only every third connection is broken, as is common, hundreds of connections have to be made and broken during tripping. Thus, the tripping process is one of the most time consuming and labor intensive operations performed on the drilling rig. 
         [0008]    Currently, there are a number of devices utilized to speed tripping operations by automating or mechanizing the process of making and breaking a threaded pipe connection. These devices include tools known as power tongs, iron roughnecks, and pipe spinners. Many of these devices are complex pieces of machinery that require two or more people to operate and require multiple steps, either automated or manual, to perform the desired operations. Additionally, many of these devices grip the pipe with teeth that can damage the drill pipe and often cannot be adjusted to different pipe diameters without first replacing certain pieces, or performing complex adjustment procedures. 
         [0009]    In particular, roughnecks combine a torque wrench and a spinning wrench, simply called a spinner, to connect and disconnect drill pipe joints of the drill string. In most instances, the spinner and the torque wrench are both mounted together on a carriage. To make or break a threaded connection between adjoining joints of drill pipe, certain roughnecks have a torque wrench with two jaw levels. In these devices, an upper jaw of the torque wrench is utilized to clamp onto a portion of an upper tubular, and a lower jaw clamps onto a portion of a lower tubular (e.g., upper and lower threadedly connected pieces of drill pipe). After clamping onto the tubular, the upper and lower jaws are turned relative to each other to break or make a connection between the upper and lower tubulars. A spinner, mounted on the carriage above the torque wrench, engages the upper tubular and spins it until it is disconnected from the lower tubular (or in a connection operation, spins two tubulars together prior to final make-up by the torque wrench). 
         [0010]    Generally, a spinner comprises four rollers, each driven by a separate hydraulic motor, that engage the outer wall of the drill pipe to spin the pipe. However, other spinners exists that use flexible belts or chains to engage and spin the pipe. An example of a chain spinner is the SPINMASTER® spinner made available from Hawk Industries. The basic function and construction of the SPINMASTER® spinner are disclosed in U.S. Pat. No. 4,843,924 (Hauk). 
         [0011]    In particular, the Hauk &#39;924 patent discloses a spinner that includes first and second elongate casing sections that are pivotally connected to each other at a pivot, and first and second driven sprockets mounted, respectively, on the casing sections at locations remote from the pivot. The spinner also includes a drive sprocket, mounted on the first casing section, driven by a motor-gear assembly and a continuous chain mounted around the drive sprocket, and around the first and second driven sprockets. The chain has an inverse internal portion adapted to receive and directly contact a tubular well element to be rotated. Cylinders connected between the casing sections pivot them toward and away from each other and thus, alternately clamp the inverse internal portion around the well element, and release such element from the inverse internal portion of the chain. 
         [0012]    Some prior art spinners, such as the SPINMASTER®, are also adjustable to accommodate pipes of varying diameter. These spinners are adjusted by changing the location of the drive sprocket relative to the driven sprockets, thus the effective length of the chain is adjusted to accommodate different pipe diameters. While adjustable spinners are versatile, these spinners must be manually adjusted by the operator during use. In many instances, the operator must climb atop of the spinner, disengage fasteners or locking pins holding the drive sprocket in place, manually adjust the drive sprocket to a desired location, and re-fasten or lock the drive sprocket at its new location. Manually adjusting the spinner can therefore be consuming and dangerous. 
         [0013]    Thus, a need exists for an automated spinner that allows the operator to change the pipe size of the spinner from a remote location to provide a safer and quicker pipe change. 
       SUMMARY 
       [0014]    A self-adjusting spinner is provided that is capable of accommodating various pipe sizes without requiring the need for an operator to climb up the support mechanism and manually change the position of the drive assembly. The self-adjusting spinner includes a case having two pivotally connected members: a stationary case member and a moving case member. Upper and lower plates having gear racks are mounted on the stationary case member for moving a drive assembly horizontally across the case. The drive assembly includes a motor that drives gear sprocket through a drive shaft. The drive sprocket then drives a chain that rotates a drill pipe in an operative position relative to the case. The spinner also includes an adjusting assembly mounted on the case that moves the drive assembly along the gear rack upon the actuation of an adjustment sequence. When the adjustment sequence is initiated, the effective length of the chain is adjusted to accommodate drill pipes of varying diameters. 
         [0015]    In another aspect of the invention, a method for operating a pipe spinner having a chain positioned inside a case is provided. The method includes the steps of receiving a pipe within the case, where the case has a stationary member and a movable arm member pivotally connected to the stationary member, pivoting a moving arm member toward the stationary member to surround the pipe with the chain, and applying tension to the chain by remotely engaging a drive assembly on the case that is moveable relative to the stationary member. 
         [0016]    Other devices, apparatus, systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0017]    The invention may be better understood by referring to the following figures. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views. 
           [0018]      FIG. 1  is a side view of a drill pipe making and breaking apparatus that incorporates a self-adjusting pipe spinner of the invention. 
           [0019]      FIG. 2  is a perspective view of one example of an implementation of a self-adjusting spinner of the invention. 
           [0020]      FIG. 3  is a side view of the self-adjusting spinner of  FIG. 2 . 
           [0021]      FIG. 4  is an enlarged side view of the rear of the case of the self-adjusting spinner of  FIG. 3 , illustrating the engagement of the motor clamp assembly on the rear of the case. 
           [0022]      FIG. 5  is an exploded perspective view of the self-adjusting spinner of  FIG. 2 . 
           [0023]      FIG. 6  is a top view of the self-adjusting spinner of  FIG. 2  positioned at a setting designed to receive a small diameter pipe, highlighting the position of the roller chain and the spinner motor assembly. 
           [0024]      FIG. 7  is a top view of the self-adjusting spinner of  FIG. 6  illustrated after the spinner motor assembly has been adjusted to receive a larger diameter pipe, highlighting the position of the roller chain and the spinner motor assembly after adjustment. 
           [0025]      FIG. 8  is a top view of the self-adjusting spinner of  FIG. 7  illustrated after a pipe has been inserted in the spinner and the slack in the roller chain has been removed, highlighting the position of the roller chain, pipe, and the spinner motor assembly after adjustment. 
           [0026]      FIG. 9  is a top view of the self-adjusting spinner of  FIG. 6  illustrated after the pipe has been positioned in the self-adjusting spinner and the case assembly has been closed around the pipe, highlighting the position of the roller chain and the spinner motor assembly after adjustment. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The present invention is directed to a chain spinner that can be a free hanging, separate stand alone unit, or part of a drill pipe making and breaking apparatus such as the T-WREX JR. 51200 apparatus, available from Hawk Industries, Inc. of Long Beach, Calif., as depicted in  FIG. 1 . The apparatus, referred to herein as a roughneck  50 , includes a structural frame  52  that is moveably coupled to a vertical translator  56  via an extending arm  54 . The vertical translator  56  is configured to move the structural frame  52  up and down relative to a drill string, and the extending arm  54  is configured to move the structural frame  52  towards and away from the drill string. The structural frame  52  carries a wrench assembly that includes a top wrench  58 , a middle wrench  60 , and bottom wrench  62 , and a spinner  100 . The wrenches  58 ,  60 ,  62  are configured to hold a pipe section of the drill string while the spinner  100  spins an adjoining pipe section of the drill string to make or break the drill string. 
         [0028]      FIG. 1  illustrates one implementation of an embodiment of a self-adjusting spinner  100  of the present invention. As illustrated in  FIG. 1 , the self-adjusting spinner  100  includes a case assembly  200 , a moveable drive assembly  400 , a motor adjustment assembly  500 , and a continuous roller chain  302 . The case assembly  200  includes a stationary case member  210  and a moving arm case member  240 . The stationary case and moving arm case members  210 ,  240  are configured to enclose the roller chain  302 . 
         [0029]    Referring now to  FIG. 4 , the stationary case member  210  includes an elongated sidewall  212  coupled between an upper gear mount plate  214  and a lower gear mount plate  216  ( FIG. 3 ). The sidewall  212  and the upper and lower gear mount plates  214 ,  216  define a substantially U-shaped channel for receiving the roller chain  302 . 
         [0030]    The upper gear and lower mount plates  214 ,  216  include a corresponding pair of drill holes (not shown), corresponding elongated openings  218  that extend longitudinally along a central portion of the mount plates, and corresponding arcuate surfaces  222  and semi-circular cut-outs  224  ( FIG. 5 ) located near the front of the case assembly  200 . The elongated openings  218  are configured to receive a base portion of the drive assembly  400 , such that the drive assembly  400  may be moveable along the length of the openings  218 . 
         [0031]    Now turning to the moving arm member  240 , this member includes an elongated sidewall  242  coupled between an upper mount plate  244  and lower mount plate  246 . The sidewall  242  and the upper and lower mount plates  244 ,  246  define a substantially U-shaped channel for receiving the roller chain  302 . 
         [0032]    The upper and lower gear mount plates  214 ,  216  of the stationary case member are configured to engage the upper and lower mount plates  244 ,  246  of the moving arm case member  240  as the moving arm case member  240  is rotated towards the stationary case member  210 . The upper and lower mount plates  244 ,  246  include a corresponding pair of drill holes  248 , and corresponding arcuate surfaces  250  and semi-circular cut-outs  252  located near the front of the case assembly  200 . 
         [0033]    According to an implementation of the invention, all or a portion of the casing assembly  200  may be constructed from durable metal. For example, in one implementation all or a portion of the case assembly  200  may be constructed from mild steel. Further, the case assembly may be manufactured by a variety of means. For example, in one implementation the mounting plates and sidewalls of the case assembly may be integrally formed, or laser cut, formed, and welded together on the tooling gig. Alternatively, the sidewalls may be fastened to the mounting plates by, for example, rivets, bolts, or any other suitable fasteners. 
         [0034]    As best shown in  FIG. 5 , the moving arm case member  240  is rotatably coupled to the stationary case member  210  at a pivot P ( FIG. 5 ) near the rear of the case assembly  200 , such that the moving arm case member  240  is able to move toward and away from the stationary case member  210  to engage a pipe  602  positioned in the case assembly  200 , as illustrated in  FIGS. 6-8  below. The moving arm case member  240  and the stationary case member  210  are coupled together by a bolt and lock nut assembly that extends through a corresponding pair of bores  226  located at rear ends of the moving arm and stationary case members  240 ,  210 . 
         [0035]    Now turning back to  FIG. 4 , the moving arm case member  240  is moved toward and away from the stationary case member  210  by an upper grip actuator  260  and a lower grip actuator  262 . In one implementation, the grip actuators  260 ,  262  are linear double acting hydraulic cylinders, but it would be obvious to one skilled in the art that any suitable actuator may be applied. 
         [0036]    In this example, the upper grip actuator  260  is rotatably mounted horizontally across the case assembly  200  at one end by an upper mounting support  270  positioned on the stationary case member  210  and, at the other end, by a second upper mounting support  274  positioned on the moving arm case member  240 . The lower grip actuator  262  is rotatably mounted horizontally across the case assembly  200  at one end by a lower mounting support  272  positioned on the underside of the stationary case member  210  and, at the other end, by a second lower mounting support  276  positioned on the underside of the moving arm case member  240 . The grip actuators  260 ,  262  are mounted to the mounting supports  270 ,  272 ,  274 ,  276  by retaining bolt and lock nut assemblies extending through the ends of the actuators. These retaining bolts also extend through idler rollers  278  positioned between the mounting supports  270 ,  272 ,  274 ,  276 . 
         [0037]    As will be described in more detail below, the upper and lower grip actuators  260 ,  262  are generally maintained in an open (or fully extended) position to receive the pipe  602  within the case assembly  200 . Once the pipe  602  is positioned within the case assembly  200 , the grip actuators  260 ,  262  are activated to move the moving arm case member  240  towards the stationary case member  210  to grip the pipe  602 . 
         [0038]    The idler rollers  278  correspond with and are disposed between corresponding drill holes  228  in the moving arm and stationary case members  240 ,  210 . The idler rollers  278  are free to rotate relative to the moving arm and stationary case members  240 ,  210  and are maintained in spaced apart relation from the sidewalls  212 ,  242  to form a passage for passing the chain  302  therethrough. The idler rollers  278  are adapted to slidably engage the roller chain  302  as it rotates within the case assembly  200 . In an implementation, the idler rollers  278  may be made from heat treated alloy steel or any other durable metal. 
         [0039]    Driven roller assemblies  310 ,  312  are positioned in the semi-circular cut-outs  224 ,  252  at ends of the stationary and moving arm case members  210 ,  240  opposite the pivot P. The driven rollers  310 ,  312  attached to the stationary and moving arm case members  210 ,  240  are free to rotate relative thereto. Each roller  310 ,  312  includes a pair of bearing caps  320  that retain a roller sprocket  322  that is rotatably coupled between a pair of roller bearings  324 . The roller sprocket  322  includes a body carrying a series of teeth for engaging the chain  302  and driving it about the rollers  310 ,  312  to spin a pipe positioned between the driven rollers  310 ,  312  when the roller chain  302  is wrapped about the pipe, as illustrated in  FIGS. 6-8  below. 
         [0040]    Movement of the roller chain  302  is driven by the drive assembly  400 . The drive assembly  400  includes a gear motor  402  mounted on a planetary gear reducer  404 . In one example, the gear motor  402  may be a hydraulic motor, an air motor, or any other suitable driving mechanism. In one implementation, a gear  406  is coupled between the gear motor  402  and the rear reducer  404  to increase the torque transferred from the gear motor  402  to a drive shaft  410  coupled to the gear reducer  404  at an end opposite the motor  402 . The gear  406  is retained inside of an upper portion of the gear reducer  404  by a gear key  408 . 
         [0041]    In this way, the gear motor  402  drives the planetary gear reducer  404 , which in turn drives a drive sprocket  412  coupled to an end of the drive shaft  410  opposite the gear reducer  404 . In one implementation, the drive sprocket  412  is secured to the drive shaft  410  by a sprocket key  414 . The drive sprocket  412  carries teeth that engage (mesh) the links of the roller chain  302  to drive the roller chain  302  through the driven rollers  310 ,  312 , respectively positioned at an end of the case assembly  200  opposite the drive assembly  400 . 
         [0042]    The upper and lower gear mount plates  214 ,  216  of the stationary case member  210  are configured to movably retain the drive assembly  400  against the case assembly  200 . In one implementation, the drive assembly  400  is retained within the elongated openings  218  of the upper and lower gear mount plates  214 ,  216  by a pair of gear mounts  420 ,  422  that movably abut the upper and lower gear mount plates  214 ,  216 . In this implementation, gear mount  420  supports the gear reducer  404 , as gear mounts  420  and  422  are coupled together by fasteners that extend through a set of spacers  424  fastened between the gear mounts  420 ,  422 . The gear mounts  420 ,  422  are configured to ride between a set of upper and lower fixed racks  282 ,  284  axially mounted to the upper and lower gear mount plates  214 ,  216  about elongated openings  218 . The fixed racks  420 ,  422  may be secured to the upper and lower gear mount plates  214 ,  216  by screws, bolts, rivets, or any kind of industrial fastener. In one implementation, spacers  420 ,  422  may be configured such that the contact surfaces of gear mounts  420 ,  422  and the upper and lower fixed racks  282 ,  284  are maintained within a spaced relationship of approximately 0.050 inches. A drive shaft bearing  426  is further attached to gear mount  422  to support the drive shaft  410  of the drive assembly  400 . 
         [0043]    The drive assembly  400  is adjustably secured to the stationary case member  210  by a motor clamp assembly  450  attached to a rear end of the drive assembly  400 . As illustrated in  FIGS. 2-4 , the motor clamp assembly  450  includes a hydraulic cylinder (not shown) that activates a set of upper and lower rack clamps  452 ,  456  that compliment the upper and lower fixed racks  282 ,  284 . As better illustrated in  FIG. 3 , each rack clamp  452 ,  456  includes a set of toothed feet  454  and  458  that mesh with a complimentary set of teeth carried by the upper and lower fixed racks  282 ,  284 . Thus, when the hydraulic cylinder activates the upper and lower rack clamps  452 ,  456 , the rack clamps  452 ,  456  may be moved towards each other to engage (mesh) the rack clamps  452 ,  456  with the respective fixed racks  282 ,  284  to secure the drive assembly  400  to case assembly  200  and provide a positive lock. The positive lock prevents movement of the drive assembly  400  within the elongated openings  218 . 
         [0044]    In the alternative, the hydraulic cylinder of the motor clamp assembly  450  may cause the upper and lower gear rack clamps  452 ,  456  to move away from each other to disengage the rack clamps  452 ,  456  from the fixed gear racks  282 ,  284 , to an unlocked position. When in the unlocked position, the drive assembly  400  is released from case assembly  200  and the drive assembly  400  may be moved relative to the fixed racks  282 ,  284  to change the effective chain engagement length. (It can be slid parallel to the fixed racks  282 ,  284 , within the elongated opening  218 .) When the drive assembly  400  is in the new desired position, the operator sends a signal to the hydraulic cylinder of the motor clamp assembly  450  to lock the movable gear rack clamps  452 ,  456  in the new position (by the engaging the gear rack teeth). Because the gear racks  282 ,  284  are securely mounted to the stationary case member  214 , the drive assembly  400  is prevented from slipping while it is in the locked position. 
         [0045]    Referring to  FIG. 5 , the motor adjustment assembly  500  is provided for adjusting the position of the drive assembly  400  along the elongated openings  218  of the case assembly  200 . The motor adjustment assembly  500  includes an adjusting actuator  502  that is secured to one end of a pivot arm  504 . In one implementation, the actuator  502  may include an air cylinder, a hydraulic cylinder, or any other suitable actuating device. The adjusting actuator  502  is secured to the case assembly  200  by a mount  503  attached to the sidewall  212  ( FIG. 1 ) of the stationary case member  210 . 
         [0046]    The pivot arm  504  pivots about a pivot arm mount  506  attached to the upper gear mount plate  214 . The pivot arm  504  also carries an elongated slot  508  at an end opposite the adjusting actuator  502  that slidably engages a slide pin  510  coupled to a front end of the drive assembly  400 . In this configuration, the adjusting actuator  502  applies force to an end of the pivot arm  504  to rotate the arm  504  about the pivot arm mount  506 , thus generating torque about the pivot mount  506 . The torque generated by the adjusting actuator  502  is applied to the slide pin  510  to move the drive assembly  400  forwards and backwards within the elongated openings  218 . While a lever mechanism is presently described, other mechanisms and implementations may be used to adjust the position of the drive assembly  400  in accordance with the present invention. 
         [0047]    As illustrated in  FIGS. 5 through 8 , the roller chain  302  is a continuous chain that runs around the driven rollers  310 ,  312 , the idler rollers  278 , the drive sprocket  412 , and around the pipe  602  (see  FIGS. 6-8 ). According to one implementation, the roller chain  302  is driven by the drive sprocket  412  and configured to grip a pipe  602  without damaging its outer surface and provides sufficient friction to rotate the pipe  602  within the case assembly  200  as desired. 
         [0048]    The length of the roller chain  302  and the position of the idler rollers  310 ,  312  and their respective roller sprockets  322  result in the chain  302  having an inverse internal portion. This inverse internal portion wraps around a pipe  602  (see  FIGS. 6-8 ) inserted in the front opening of the case assembly  200  when the moving case member  240  closes relative to the stationary case member  210 , thereby enabling the chain  302  to grip the circumference of the pipe  602  and spin it. 
         [0049]    The effective length of the roller chain  300  on the pipe  602  can be adjusted by repositioning the drive assembly  400  (or more particularly the drive sprocket  412 ) relative to the pipe  602  (or the driven rollers  310 ,  312 ) via the motor adjustment assembly  500 , as discussed above. The repositioning is used to accommodate pipes  602  of different diameters, to compensate for chain “stretch” as the chain wears, and to adjust the chain gripping tension on the pipe  602 . In one implementation, the roller chain  302  may be adjustable to accommodate pipes having diameters from 3 to 9½ inches and the chain may be a heavy-duty, durable roller-style chain having eight-eight links and one inch pitch. 
       Operation 
       [0050]    In operation, as illustrated in  FIGS. 5-8 , the moving arm case member  240  may be opened and closed relative to the stationary case member  210 . The accurate surfaces  222 ,  250  of the stationary case member  210  and the moving arm case member  240  correspond to define a well  610  for receiving a section of the pipe  602 . A guide  620  mounted to the front end of the stationary case member  210  is configured to engage the drill pipe  602  if the spinner  100  is misaligned with the drill pipe  602  when the spinner  100  approaches the pipe. If the spinner is misaligned, the guide  620  will contact the pipe  602  to pivot and align the spinner  100  with the pipe  602  as the spinner  100  moves towards it. 
         [0051]    When an operator wishes to make or break a drill string section, the operator may move a roughneck carrying the spinner  100  towards a drill string. Depending on the drill pipe diameter, the operator may desire to adjust the spinner  100  to accommodate the dimensions of the drill pipe, so the operator may initiate a self-adjusting sequence to allow the operator to change the pipe size of the spinner  100 . The sequence may be initiated remotely, for example, from an operator&#39;s console (not shown). 
         [0052]    As shown in  FIG. 5 , the self-adjusting sequence begins with the spinner  100  being set at its current pipe size. For example, in the implementation depicted in  FIG. 5 , the pipe size of the spinner  100  is set at a 3 inch. pipe setting. In this setting, the drive motor assembly  400  is clamped to the stationary case member  210  at a location near the rear of the spinner  100 . In addition, the upper and lower grip actuators  260 ,  260  are maintained in their open (extended) position to receive the pipe  602 . 
         [0053]    After the self-adjusting sequence is initiated, the operator may switch a spinner adjusting switch (not shown) on, for example, the operator&#39;s remote console (not shown) to an unclamp position. When the switch is switched to this position, as shown in  FIG. 6 , a first signal is sent to the motor clamping assembly  450  to disengage the upper and lower rack clamps  452 ,  456  of the clamping assembly  450  from the upper and lower fixed racks  282 ,  284  on the stationary case member  210 . Simultaneous to the first signal, a second signal is sent to the adjusting actuator  502 , which activates the actuator to move from an open (extended) position to a closed (retracted) position. As the adjusting actuator  502  is retracted, the drive assembly  400  is moved forward towards a front end of the elongated opening  218  and slack is created in the roller chain  302  in the back of the roller chain train. 
         [0054]    Turning now to  FIG. 7 , after the drive assembly  400  is unclamped and moved forward, the roughneck is moved forward toward the center of the oil well and the spinner  100  is pushed forward towards the drill pipe  602  by a push cylinder on its mount. As the spinner  100  is moved towards the pipe  602 , the pipe  602  engages the inverse internal portion of the roller chain  302 . As the pipe  602  engages the roller chain  603 , the slack in the chain  602  is taken up. A sensor located on the roughneck wrench head is activated when the pipe reaches a certain geometrical relationship to the wrench head. Once activated, the roughneck stops its forward movement. 
         [0055]    When the roughneck is stopped, the operator may switch the spinner adjusting switch (not shown) to a center position, which activates the adjusting actuator  502  to move to the actuator towards its open (extended) position. As the actuator  502  is moved to towards its open position, the drive assembly  400  is pushed back along the elongated opening  218  to take up any residual slack in the roller chain  302 . After the drive assembly  400  is adjusted, the operator may switch the spinner adjusting switch (not shown) to a clamp position, which energizes the hydraulic motor on the motor clamp assembly  450  to engage the upper and lower rack clamps  452 ,  456  with the upper and lower fixed racks  282 ,  284 , thus locking the drive motor assembly  400  in place. 
         [0056]    Once the drive motor assembly  400  is clamped in place and the pipe  602  has been positioned in the well  610 , the operator may engage a spin button (not shown) on the operator&#39;s remote console (not shown). As shown in  FIG. 8 , once the spin button is engaged, hydraulic fluid is sent to the upper and lower grip actuators  260 ,  262 , which change the direction of the actuators from a “pushing” actuation to a “pulling” actuation. As the actuators  260 ,  262  retract, they move the moving arm case member  240  towards the stationary case member to encircle the pipe  602  with the inverse internal portion of the roller chain  302 . As the moving arm case member  240  moves closer towards the stationary case member  210 , the stationary and moving arm case members  210 ,  240  pinch the chain  302  around the pipe  602  to generate a gripping force to hold the pipe  602 . 
         [0057]    As the stationary and moving arm case members  210 ,  240  grip the pipe  602 , hydraulic pressure is built-up in a hydraulic fluid line (not shown) coupled between the grip actuators  260 ,  262  and the gear motor  402  of the drive assembly  402 . Once the hydraulic pressure reaches a certain pressure, a sequential valve (not shown) coupled in series with the hydraulic fluid line opens to send the flow of hydraulic fluid to the gear motor  402 . The hydraulic fluid starts the gear motor  402 , which in turn drives the drive sprocket  412  and the pipe  602  begins to spin. 
         [0058]    When the operator wants to make a drill string, the operator may spin the pipe  602  until the pipe  602  “shoulders out” with the adjoining pipe section (i.e., the threaded ends of the connecting pipe sections are fully engaged). When a pipe shoulders out, the spinner  100  cannot spin the pipe anymore and the gear motor just stalls out. At that point, the operator may disengage the spin button, which cuts off the flow of hydraulic fluid going to the gear motor  402 , and the inverse flow of hydraulic fluid routed to the gear motor  402  will be routed to the grip actuators  260 ,  262  to reverse the direction of the actuators back to their original open (extended) position. As the grip actuators  260 ,  262  are returned back to their open position, the grip on the pipe  602  is loosened and the operator can remove the spinner from the drill string. 
         [0059]    In the converse, when the operator wants to break a drill string, the operator may spin the pipe  602  until the operator hears a rattling of the disengaged threaded portions of the adjoining pipe sections. At that point, the operator may disengage the spin button and remove the top pipe section from the roughneck. 
         [0060]    In one implementation of an embodiment of the present invention, a pneumatic control system may be used to send air signals to the hydraulic components. For example, an air-piloted directional control valve may be used to control the (push or pull) direction of the grip actuators  260 ,  262 . In this example, if the operator wants to extend the grip actuators, an air signal may be sent to one side of the directional valve. In the alternative, if the operator wants to retract the grip actuators, an air signal may be sent to the other side of the directional valve. 
         [0061]    The foregoing description of implementations has been presented for purposes of illustration and description. It is not exhaustive and does not limit the claimed inventions to the precise form disclosed. Modifications and variations are possible in light of the above description or may be acquired from practicing the invention. The claims and their equivalents define the scope of the invention.

Technology Classification (CPC): 4