Patent Abstract:
A tubular member handling apparatus is a gripping tool ( 100 ) in the form of a body ( 110 ) having a longitudinal axis ( 202 ) and formed by a plurality of sleeves ( 750 ) connected end to end, each sleeve including a frusto-conical bore  752  centered on said longitudinal axis; a clamp member ( 700 ) in each sleeve formed by clamp-segments ( 740 ), each having side faces ( 168 ), end faces ( 743 ), a frusto-conical exterior surface ( 741 ) adapted to match said frusto-conical bore, and a cylindrical interior surface ( 745 ); cage-segments ( 220 ) connected to said interior surface and having a plurality of windows ( 222 ) partially closing recesses ( 214 ) in said interior surface, which recesses are elongate in said longitudinal direction, house a roller ( 230 ) and have a base ( 236 ) inclined in said longitudinal direction so that, at a lower end ( 232 ) of each recess the roller protrudes through said window and at an upper end ( 234 ) thereof the roller protrudes less or not at all; a bias mechanism  780 , urging said clamp-segments apart from each other in a peripheral direction; connection means ( 160 ) between adjacent clamp segments so that they move together when one is moved axially.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage entry of PCT/GB2009/050741 filed on Jun. 26, 2009, which is a continuation-in-part and claims priority to U.S. patent application Ser. No. 12/147,223 filed on Jun. 26, 2008. 
     This invention relates to a device for handling circular cylindrical tubular objects, with or without intervening bulges or flanges at their ends or intermediate their length. Furthermore it relates to a device that can grip such a tubular object not just for the purpose of lifting the object (in a direction including vertically upwardly in a direction parallel a longitudinal axis of the object), but also for the purpose of applying torque to the object about said longitudinal axis. 
     BACKGROUND 
     The drilling of subterranean wells involves assembling tubular strings, such as casing strings and drill strings, each of which comprises a plurality of heavy, elongated tubular segments extending downwardly from a drilling rig into a wellbore. The tubular string consists of a number of threadedly engaged tubular segments. 
     Conventionally, workers use a labor-intensive method to couple tubular segments to form a tubular string. This method involves the use of workers, typically a “stabber” and a tong operator. The stabber manually aligns the lower end of a tubular segment with the upper end of the existing tubular string, and the tong operator engages the tongs to rotate the segment, threadedly connecting it to the tubular string. While such a method is effective, it is dangerous, cumbersome and inefficient. Additionally, the tongs require multiple workers for proper engagement of the tubular segment and to couple the tubular segment to the tubular string. Thus, such a method is labour-intensive and therefore costly. Furthermore, using tongs can require the use of scaffolding or other like structures, which endangers workers. 
     Others have proposed a running tool utilizing a conventional top drive assembly for assembling tubular strings. The running tool includes a manipulator, which engages a tubular segment and raises the tubular segment up into a power assist elevator, which relies on applied energy to hold the tubular segment. The elevator couples to the top drive, which rotates the elevator. Thus, the tubular segment contacts a tubular string and the top drive rotates the tubular segment and threadedly engages it with the tubular string. 
     While such a tool provides benefits over the more conventional systems used to assemble tubular strings, it also suffers from shortcomings. One such shortcoming is that the tubular segment might be scarred by the elevator gripping dies. Another shortcoming is that a conventional manipulator arm cannot remove single joint tubulars and lay them down on the pipe deck without worker involvement. 
     Other tools have been proposed to cure these shortcomings. However, such tools are often unable to handle tubulars that are dimensionally non-uniform. When the tubulars being handled are not dimensionally ideal, such as by having a varying wall thickness or imperfect circularity of tube section, the ability of tools to adequately engage the tubulars is decreased. 
     There are many other circumstances in which it is desirable to handle other tubular objects. Indeed, the general handling of large pipe sections can be problematic, and a convenient tool for grabbing and loading pipes is desirable. Indeed, very large pipe sections (with a weight in the order of 6000 kN) are frequently provided with lifting and handling handles, but these generally require personnel to ensure appropriate hook up and disconnect. It would be desirable if a pipe could be provided with a simple mechanism for safe connection and disconnection of a lifting device that did not require human intervention at the site of connection. Of course, much smaller pipe sections might be provided with such lifting arrangements. 
     Floor slips are employed on production sites to hold casings and drill pipes being lowered into a well while a new length is connected to the top of the pipe or casing being held. An appropriate design of holder that did not need to open to allow flanges and the like on the casings and drill pipes to navigate through the floor slip, as well as not requiring human intervention in the immediate vicinity of the floor slip during holding and release operations, would be desirable. 
     Emergency disconnect packages are employed to connect rigid risers from subsea installations to surface vessels. Such vessels generally dynamically hold position above a riser but adverse weather conditions and sometimes an inability to maintain position require the possibility of an emergency disconnection from the riser. A device capable performing such function is desirable. 
     PRIOR ART 
     WO2008/085700 discloses a tubular handling apparatus, comprising: a slotted member having a plurality of elongated slots each extending in a direction; a recessed member slidably coupled to the slotted member and having a plurality of recesses each tapered in the direction from a shallow end to a deep end; and a plurality of rolling members each retained between one of the recesses and one of the slots; wherein each rolling member partially extends through the adjacent slot when located in the shallow end of the recess; and wherein each rolling member retracts within an outer perimeter of the slotted member when located in a deep end of the recess. Such apparatus is useful in gripping to both internal and external surfaces of tubulars. However, if the tubular has peripheral extensions then the slotted member cannot necessarily move over such extensions during positioning of the apparatus on the tubular. 
     WO2004/067854 discloses a tool for gripping a tubular object by contact with opposed surfaces thereof comprising a mandrel having means for attachment to lifting gear, at least one pair of gripping assemblies attached to the mandrel, each gripping assembly comprising a body member, a wedge member slidably movable on an individual ramp with respect to the body member towards and away from the mandrel, and a ball or roller cage slidably movable with respect to the wedge member and having at least one ball or roller movable with the ball or roller cage on an inclined ramp with respect to the wedge member thus to grip one of said opposed surfaces of the tubular object to be gripped. An annular array of such gripping assemblies may be attached to the mandrel, each with a wedge member and a ball or roller cage, such that each ball or roller is caused to make annular contact with the wall surface of the object of circular section. Such an arrangement is complex. Moreover, torque cannot be applied through the tool to the object gripped by it. However, it also discloses a plurality of arrays, one above the other. 
     US2005/0160881 discloses a clamping mechanism for applying torque, having two or more jaws that may be opened to allow a tubular to be introduced within the jaws and closed to retain the tubular therewithin. Rollers are located within concave recesses and maintained in spaced apart relationship by biasing means, whereby rotation of tubular may cause the rollers to be wedged between a wall of the recess and the tubular to grip the tubular within the jaws. The clamping mechanism may be utilized as an oil field tubular clamp, a slip, a pipe clamp, and other mechanisms. There is also disclosed a clutch comprising an outer race, a cage, and an inner ring. Recesses are provided in an outer race and accommodate rollers therewith and maintained in spaced apart relationship by the cage. 
     It is an object of the present invention to provide a relatively simple structure that is not only capable of lifting, but also of applying torque when desired. 
     It is another object to provide a device that is capable of permitting large diameter sections of tubular to pass through the device when it is in a release condition without it having to be opened and removed from the tubular. 
     It is a further object to provide a device that can be released rapidly from, and with less force than the clamping force applied by the device in, its locked condition. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention there is provided a gripping tool in the form of a body having a longitudinal axis and formed by a plurality of sleeves connected end to end, each sleeve including a frusto-conical bore centered on said longitudinal axis;
         a clamp member in each sleeve formed by clamp-segments, each having side faces, end faces, a frusto-conical exterior surface adapted to match said frusto-conical bore, and a cylindrical interior surface;   cage-segments connected to said interior surface and having a plurality of windows partially closing recesses in said interior surface, which recesses are elongate in said longitudinal direction, house a roller and have a base inclined in said longitudinal direction so that, at a lower end of each recess the roller protrudes through said window and at an upper end thereof the roller protrudes less or not at all;   a bias mechanism, urging said clamp-segments apart from each other in a peripheral direction;   connection means between adjacent clamp segments so that they move together when one is moved axially.       

     Preferably, said connection means is a bolt passing longitudinally through all longitudinally aligned clamp-segments and clamping them together axially. 
     Preferably, a top one each of said clamp-segments has a lift eye by which said clamp elements may be lifted with respect to said sleeves so that said clamp-segments slide up said frusto-conical bore separating from one another in a peripheral direction as they progress. 
     Preferably, a key on one of said frusto-conical surfaces slides in a groove in the other of said frusto-conical surfaces whereby torque applied to said sleeves is transmitted to said clamp-segments. Preferably, said key and slot are parallel the cone angle of said frusto-conical surfaces. 
     Preferably, said key and slot are central in said clamp-segment between said side faces. Preferably, there are three clamp-segments. 
     Preferably, said side faces are planar and disposed in radial planes with respect to said longitudinal axis. Preferably, between a clamp position and an open position of the tool, the segments move from position in which the arcs of the cage segments lie in a common cylindrical surface and the frusto-conical surfaces are flush with each other, to a release position in which said side faces are spaced from one another and said frustoconical surfaces have only line contact between them. 
     Alternatively, said frusto-conical surfaces are inclined part-cylindrical surfaces. 
     Preferably, said sleeves are seated in a hollow housing tube. The tube and sleeves may have between them a key whereby torque applied to the housing is transmitted to said sleeves. Said housing may have a cylindrical bore with an internal ledge at its bottom end, said sleeves being loaded from a top end, a bottom one seating on said ledge and succeeding ones seating on the one below. 
     Preferably, said rollers are balls and said recesses have a semi-circular base of diameter substantially equal to the diameter of the balls. 
     Preferably, said bias mechanism comprises a spring between each facing side face of adjacent clamp-segments. 
     Thus, when said lifting eyes are each attached to a lifting cable that lifts the clamp segments, the segments separate sufficiently to release any tubular clamped between the clamp-segments. That is to say, preferably the angle of inclination with respect to the longitudinal axis of the frusto-conical surfaces is greater than the angle of inclination of the recess bases. The latter is preferably between 3 and 10 degrees, preferably between 5 and 8 degrees. The former is preferably between 10 and 20 degrees, and more preferably between 13 and 16 degrees. 
     Preferably, the tool is designed to clamp on tubular members whose diameter is such that, when the clamp-segments abut one another with mating side faces and the frustoconical surfaces are also mating, the rollers when they evenly contact the tubular are nearer the top end of the recess than the bottom. This provides maximum tolerance while still maintaining the strongest connections between the clamp-segments and sleeves. Of course, should the tubular be larger then it is possible that the rollers may be at the top of their recesses in contact with the tubular and yet the clamp-segments are not in mating contact side face to side face. This is still acceptable since the segments are wedged firmed between the mating cylindrical surfaces of the tubular and their interior surfaces and frusto-conical surfaces (in fact preferably inclined cylindrical) surfaces of the exterior surface of the clamp-segments and the bores of the sleeves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. 
         FIGS. 1   a, b  and  c  are respectively, a cutaway perspective view of a two-sleeve gripping tool in accordance with the present invention, a tubular housing, and an exploded view of the tool of  FIG. 1   a;    
         FIG. 2  is a side section illustrating general principle of operation of a tool according to the present invention; 
         FIG. 3  is an exploded side view of a clamp segment and assembled view of two others forming a partially complete clamp member used in another embodiment of the present invention; 
         FIGS. 4   a  and  b  are side sections of a four-sleeve gripping tool using the clamp members of  FIG. 3 ,  FIG. 4   a  showing the tool in its closed or clamping position and  FIG. 4   b  showing the tool open; 
         FIG. 5  is a perspective cutaway view of the tool of  FIGS. 4   a  and  b ; and 
         FIG. 6  is a side section illustrating a size benefit of a tool according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. 
     Referring to  FIGS. 1   a  to  c , illustrated are perspective views of at least a portion of an apparatus  100  according to one or more aspects of the present disclosure. The tool  100  comprises a tubular housing  110 . 
     Tool  100  is configured to receive and at least temporarily grip, frictionally engage, or otherwise retain a tubular member  105  (shown in  FIG. 2 ). For example, the tool  100  may be configured to grip or otherwise frictionally engage an exterior surface of the tubular member  105 . The extent to which the tool  100  engages the tubular member  105  may be sufficient to support a safe working load (SWL) of at least 5 tons. However, other SWL values for the tool  100  are also within the scope of the present disclosure. 
     Furthermore, the extent to which the tool  100  engages the tubular member  105  may also be sufficient to impart a torsional force to the tubular member  105 , such as may be transmitted through a running tool (not shown) from a top drive or other component of a drill string (also not shown). In an exemplary embodiment, the torque which may be applied to the tubular member  105  via the tool  100  may be at least about 6700 Nm (about 5000 ft-lbs), which may be sufficient to “make-up” a connection between the tubular member  105  and another tubular member. The torque which may be applied to the tubular member  105  may additionally or alternatively be at least about 67,000 Nm (about 50,000 ft-lbs), which may be sufficient to “break” a connection between the tubular member  105  and another tubular member. However, other torque values are also within the scope of the present disclosure. 
     The tubular member in question may be a wellbore casing member, a drill string tubing member, a pipe member, a collared tubing member, and/or other tubular elements. The tubular member  105  may be a single tubular section, or pre-assembled double or triple sections. The tubular member  105  may be or comprise a section of a pipeline, such as may be utilized in the transport of liquid and/or fluid materials. The tubular member  105  may alternatively be or comprise one or more other tubular structural members. The tubular member may have an annulus cross-section having a substantially circular cylindrical shape, although approximations thereof may be engaged. 
     The tubular member  105  may not be dimensionally uniform or otherwise ideal. That is, the tubular member may not exhibit ideal roundness or circularity, such that all of the points on an outer surface of the tubular member  105  at a certain axial position may not form a perfect circle. Alternatively, or additionally, the tubular member  105  may not exhibit ideal cylindricity, such that all of the points of the outer surface may not be equidistant from a longitudinal axis  202  of the tool  100 , and/or the tubular member  105  may not exhibit ideal concentricity, such that the axes of all cross sectional elements of the outer surface may not be common to the longitudinal axis  202 . 
     Referring to  FIG. 2 , illustrated is a sectional view of at least a portion of an exemplary embodiment of a clamping member  700  of the tool  100  about a tubular member  105 . The clamping member  700  includes a recessed member  210 , a slotted or otherwise perforated cage member  220 , and a plurality of rolling members  230 . 
     The recessed member  210  is substantially cylindrical when formed, having a plurality of recesses  214  therein. The cage member  220  is typically slotted with windows  222  but is not limited to such a configuration. The cage member  220  is fixed to the recessed member  210 , preferably by screws (not shown, although see screws  501  in  FIG. 5 ). Each slot or window  222  is configured to cooperate with one of the recesses  214  of the recessed member  210  to retain one of the rolling members  230 . Moreover, each recess  214  and slot  222  is configured such that, when a rolling member  230  is moved further away from the maximum depth  214   a  of the recess  214  (that is, to a lower end  232  of the recess), the rolling member  230  protrudes further through the slot  222  and beyond an inner perimeter  224  of the slotted member  220 , and when the rolling member  230  is moved towards the maximum depth  214   a  of the recess  214  (that is, to an upper end  234 ), the rolling member  230  also moves towards a retracted position within the inner perimeter  224  of the slotted member  220 . That is to say, the bases  236  of the recesses are inclined with respect to the longitudinal axis  202  and are inclined inwardly and downwardly with respect to the normal orientation of the tool in use (which is as shown in  FIG. 2 ). 
     Each slot  222  may have an oval or otherwise elongated profile, such that each slot  222  is greater in length than in width. The length of the slot  222  is in the direction of the longitudinal axis  202  of the tool  100 . The walls of each slot  222  may be tapered radially inwardly. 
     Each recess  214  may have a width (into the page in  FIG. 2 ) that is at least about equal to or slightly larger than the width or diameter of each rolling member  230 . Each recess  214  may also have a length that is greater than a minimum length of the slot  222 . The width or diameter of the rolling member  230  is at least larger than the width of the internal profile of the slot  222 . 
     Because each slot  222  is elongated in the direction of the taper of the recesses  214 , each rolling member  230  may protrude from the slotted member  220  an independent amount based on the proximate dimensional characteristics of the tubular member  105 . For example, if the outer diameter of the tubular member  105  is smaller near the end  105   a  of the tubular member  105 , the rolling member  230  located nearest the end  105   a  of the tubular member  105  protrudes from the slotted member  220  a greater distance relative to the distance which the rolling member  230  nearest the central portion of the tubular member  105  protrudes from the slotted member  220 . 
     Each of the rolling members  230  may be or comprise a substantially spherical member, such as a steel ball bearing. However, other materials and shapes are also within the scope of the present disclosure. For example, each of the rolling members  230  may alternatively be a cylindrical or tapered pin configured to roll up and down the ramps defined by the recesses  214 . 
     Referring to  FIG. 3 , illustrated is an exploded perspective view of the clamping member  700  of  FIG. 2 . From  FIG. 3 , it can be seen that the clamping member  700  actually comprises (in this embodiment) three clamping segments  700   a,b,c , segment  700   a  of which is shown exploded and separated from the other two. From this it can also be seen that the slotted cage member  220  and recessed member  210  are likewise each in three segments. 
     The tool  100  also includes a holder  740  which also comprises three discrete sections  740   a,b,c . Other functionally equivalent configurations may combine holders  740   a,b,c  and recessed member  210   a,b,c  to create an integral member in each case. Each holder section  740   a,b,c  may include a flange  745  configured to be coupled with a flange  745  of another of the holder sections  740   a,b,c , such that the holder sections  740   a,b,c  may be assembled to form a bowl-type structure configured to hold the recessed sections  210   a,b,c  of the recessed member  210 , as well as sections  220 , and the rolling members  230 . 
       FIGS. 4A and 4B  are side sectional views of the clamping member  700  shown in  FIG. 3  in engaged and disengaged positions, respectively. Referring to  FIGS. 4A and 4B  collectively, with continued reference to  FIG. 3 , the tool  100  includes multiple clamping members  700  stacked vertically. Hereinafter, the clamping members  700  may also be referred to as vertical segments to reflect their vertically stacked arrangement. In the exemplary embodiment shown in  FIGS. 4A and 4B , the apparatus  100  includes four vertical segments  700 . In other embodiments, however, the apparatus may include fewer or more segments. The gripping force applied by the apparatus to the tubular member is at least partially proportional to the number of vertical segments (clamping members)  700 , such that increasing the number of segments  700  increases the lifting capacity of the apparatus  100 , as well as the torque which may be applied to the tubular member by the apparatus. Each of the vertical segments  700  may be substantially similar or identical, although the top and bottom segments  700  may have unique interfaces for coupling with additional equipment between a top drive (not shown), for instance, and the casing string. Indeed, bottom clamping member  700   d  is shown with an additional skirt  760  to receive bottom holder  740   d , as described further below. 
     The external profile of each holder  740  is tapered at  770  in a frusto-conical fashion, (although, preferably, the frusto-cone is the special case of a circular cylinder and, instead, the axis of the cylindrical surface  770  is merely inclined towards (and so as to intersect) the longitudinal axis  202  of the tool), such that the lower end of each holder  740  has a smaller diameter than its upper end. Each vertical segment  700  of the apparatus  100  also includes a tubular housing sleeve  750  having an internal profile configured to cooperate with the external profile  770  of the holder  740  such that as the holder  740  moves downward (relative to the housing sleeve  750 ) towards the engaged, clamping, position ( FIG. 4   a ) the holder  740  constricts radially inward. Yet, when the holder  740  moves upward, towards the disengaged position ( FIG. 4   b ) the holder  740  expands radially outward. 
     The top segment  700   a  of the apparatus  100  may include an interface (hook eye)  760  configured to couple with one or more hydraulic cylinders and/or other actuators (not shown). Moreover, each holder  740  is coupled to its upper and lower neighboring holders  740 . Consequently, vertical movement urged by the one or more actuators coupled to the interface  760  results in simultaneous vertical movement of all of the holders  740 . Accordingly, downward movement of the holders  740  driven by the one or more actuators causes the rolling members  230  to engage the outer surface of the tubular member  105 , whereas upward movement of the holders  740  driven by the one or more actuators causes the rolling members  230  to disengage the tubular member  105 . The force applied by the one or more actuators to drive the downward movement of the holders  740  to engage the rolling members  230  with the tubular member  105  is one example of a preload that can be applied in order to pre-grip the tubular member  105  if gravity is not available to press the holder downwardly. 
     Referring back, now, to  FIGS. 1   a, b  and  c , tool  100  is a two-section tool, having two clamping members  700   d,e  vertically aligned. Tubular housing  110  here comprises a simple tube having a bottom internal flange  152  on which external flange  154  of bottom housing  750   d  seats. Bottom flange  156  of top housing  750   e  seats on top edge  158  of bottom housing  750   d . A key  170  is fixed internally of the housing  110  by bolts  171  and slides in axially extending slots  172  on the outside of the housing sleeves  750   d,e . Torque can then be transmitted by the housing  110  to the sleeves  750   d,e.    
     Each vertically aligned holder  740  is interconnected by a pair of bolts  160 . A spacer  162  and spring  164  being disposed between them and the connection being completed by a lock nut  166  that, when tightened, permits some relative vertical movement between holders  740 . The purpose of this is to permit each clamping member  700   d,e  to independently clamp on the tubular member  105 . 
     In use, tubular member  105  is inserted from underneath the tool  100 . Prior to this, the holders  740  have been lowered into the tubular housing  110  and sleeves  750   d,e  so that they collapse inwardly to the clamping position depicted in  FIG. 4   a  where radial faces  168  of adjacent holder sections  740   a,b,c  abut one another. In this position, the cage members  220  and internal face of the holders  740  (which here constitute also the recessed member  210  of  FIG. 3  described above) are essentially on surfaces of the same cylinder. This cylinder coincides with the design cylinder of tubular members  105  the tool is intended to handle. However, when inserted from underneath, the tubular may not be absolutely true. Indeed, the internal frusto-conical surfaces of the housing sleeves  750   d,e  or the corresponding external surfaces  770  of the holders  740  might exhibit some tolerance. Finally, the pickup by the rollers  230  may also show some variation. These differences are to some extent accommodated and shared between the two clamp members  700   d,e  when a small freedom of movement between them is permitted, as provided by the bolts  160 . Thus, when inserted from underneath and then the tubular housing  110  is lifted, the rollers  230  progressively bite into the tubular member  105 . Some rollers  230  may not bite to the same extent as others, and the partial separation of the holders  740  permits some tolerance to be accommodated. 
     The holders have said frusto-conical external surfaces  770 , as described above. These mate with corresponding frusto-conical internal surfaces  752  of the housing sleeves  750 . The surfaces  770  include keys  742  that fit in slots  754  in the housing sleeves  750 . If the surfaces  770 , 752  are truly conical, then they only mate in area contact in one axial position, which is arranged to be when the radial faces  168  of the holder sections  740   a,b,c  abut. In this event, as the holders  740  rise up, only a line contact remains between the surfaces  770 , 752 . Accordingly, it is preferred, as stated above, that the engaging surfaces  770 , 752  are inclined cylindrical surfaces, in which event there is area contact in all axial positions. However, since there is only load applied when the holders  740  are in their clamp position, it is not a significantly important point. However, the keys  742  are preferably central in each holder  740 . The keys  742  transmit torque between the housing sleeves  750  and the holders  740 . 
     When a tubular member  105  is to be released by the tool  100 , the weight of the tubular member  105  is taken from the tool  100  by other means (not shown). These means may simply comprise the tubular member  105  reaching a limit of travel after being lowered into a well bore. Alternatively, such means may comprise a floor slip arrangement (that may itself take the form of a tool according to the present invention). When the weight has been released, the holders  740  are lifted within the housing sleeve  750 . When the holders  740  rise relative to the housing sleeves  750 , springs  780  press the radial faces  168  apart. The tapered surfaces  770 ,  752  of the holders  740  and housing sleeves  750  allow the clamp segments to spread significantly, whereby not only is the tubular member  105  released, but also enlargements that may be in the tubular member  105  can pass through the tool  100 . This is frequently the case in drill strings where connections between adjoining drill pipe sections may have an enlarged diameter. 
     The taper on the surfaces  770 , 752  is preferably about 15 degrees with respect to the longitudinal axis  202 . Although shown much greater in  FIG. 2 , the inclination of the bases of the recesses  214  to the longitudinal axis is only about 10 degrees. The effect of this is that lifting the holders  740  immediately releases the clamping pressure without requiring significant force. Indeed, the arrangement is such that, in some applications, it is unnecessary to relieve the load of the tubular member  105  before releasing the tool  100 . Such may be required in emergency situations. Indeed, umbilical connections between undersea installations and surface vessels often must be suddenly released and the present arrangement provides this capacity. 
     An advantage provided by dividing the clamping members  700  into short vertical sections is that the inclined surface needed to support a sufficiently long axial length for the holders  740  to attain sufficient grip on the tubular member  105  for the loads being envisaged can be provided in a relatively restrained diameter.  FIG. 6  illustrates the profile  600  that a single vertical section tool would need to have if it were to have the same gripping power of a twin-section tool  100  as shown in  FIGS. 1   a,b  and  c . This is achieved simply by extending the taper  602  of the lower section as it would need to proceed if only a single clamp section was employed. Not only would this increase the dimensions of the tool (from diameter d to D in  FIG. 6 ) but also the mass of the tool would commensurately be increased. Indeed, by constructing the housing from several components (the tubular housing  110  and housing sleeves  750 ) a particularly compact design is achieved, and one that is relatively easy to manufacture since there are few undercuts to be made. 
     Each holder section  740   a,b,c  therefore has said frusto-conical external surface  770  (within the meaning of which is included inclined cylindrical or other approximation thereof) radial faces  168  (which in the arrangements illustrated are in radial planes, but this is not essential—therefore, the radial faces  168  may also be referred to as side faces) abutting end faces (see top face  743  in  FIGS. 1   a  and  c  on which said lifting eyes  760  are fixed) and cylindrical and recessed internal face  746  (not visible except in  FIGS. 2 and 3 ), which may be constituted in a separate component  210 . 
     The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the scope of the present disclosure. 
     For example, embodiments of the invention, with suitable adaptation that would be evident to the person skilled in the art, have applications not limited to floor slips, handling apparatus and emergency disconnect devices. 
     In the case of floor slips, for example, the release of the tubular is easily and quickly effected by lifting the clamping members within the tubular housing sleeve. The spread of the individual segments on such lifting opens the aperture through the tool so that bulges and other flanges on the drill pipe or casing being controlled by the floor slip can pass through the tool without the need to open the tool and remove it laterally from the tubular. 
     In the case of handling equipment generally, or specifically for large pipe sections, for example, a simple tube or rod can be provided as a handle to be gripped by the tool of the present invention. Indeed, a flange can be disposed on the end of the handle in the event that the grip of the tool should falter or fail and whereby the flange will catch on the upper surface of the holder and press it into tighter engagement with the handle. In the locked position of the holder, the flange would be unable to pass through the tool, whereby a safety mechanism is provided. However, when the tool is released in normal operation by the holder being lifted in the housing sleeve, the spread of the clamping members opens the passage between them so that the flange on the handle could be accommodated to effect normal release (and engagement) of the tool from (and with) the handle. 
     In the case of emergency disconnect packages, the force needed to lift the holder is much less than the clamping force effect by the holder on the tubular it is gripping, whereby rapid disconnection is facilitated. 
     Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. 
     Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. 
     The reader&#39;s attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. 
     REFERENCE NUMERALS 
     
         
         
           
               100 —tool capable of lifting and applying torque 
               105 —tubular abutment/tubular member 
               105   a —end of tubular member  105   
               110 —tubular housing (of tool  100 ) 
               152 —bottom internal flange (of tubular housing  110 ) 
               154 —external flange (of bottom housing  750   d ) 
               156 —bottom flange (of top housing  750   e ) 
               158 —top edge (of top housing  750   e ) 
               160 —bolts (used in connecting vertically aligned holders  740 ) 
               162 —spacer (used in connecting vertically aligned holders  740 ) 
               164 —spring (used in connecting vertically aligned holders  740 ) 
               166 —lock nut (used in connecting vertically aligned holders  740 ) 
               168 —radial or side faces (of adjacent aligned holders  740 ) 
               170 —key (of tubular housing  110 ) 
               171 —bolts (affixing key  170  to tubular housing  110 ) 
               172 —axially extending slots (on outside of housing sleeves  750   d,e ) 
               202 —longitudinal axis (of tool  100 ) 
               210 —recessed member (of clamping member  700 ) 
               210   a,b,c —individual segments of recessed member  210   
               214 —recesses (of recessed member  210 ) 
               214   a —maximum depth of recesses  214   
               220 —(slotted or otherwise) cage member (of clamping member  700 ) 
               222 —windows/slots (of cage member  220 ) 
               224 —perimeter of slotted member  220   
               230 —rolling members (of clamping member  700 ) 
               232 —lower ends of recesses  214   
               234 —upper ends of recesses  214   
               236 —bases of recesses  214   
               501 —screws (fixing cage member  220  to recessed member  210 ) 
               700 —clamping member/vertical segments 
               700   a,b,c —individual segments of clamping member  700   
               700   d —bottom clamping member/vertical segment 
               740 —holder (of tool  100 ) 
               740   a,b,c —discrete sections of holder  740   
               742 —keys (of external surfaces  741  of holders  740 ) 
               743 —top face or abutting end face of (top) holder  740   
               745 —flange of each section  740   a,b,c  of holder  740   
               750 —tubular housing sleeve (of each vertical segment  700 ) 
               750   d —bottom tubular housing sleeve 
               750   e —top tubular housing sleeve 
               752 —frusto-conical external surfaces (of holders  740 ) 
               754 —keys (of external surfaces  741  of holders  740 ) 
               760 —skirt (of bottom clamping member  700   d ) 
               770 —tapered, cylindrical, external profile (of each holder  740 ) 
               780 —springs (that press radial faces  168  apart)

Technology Classification (CPC): 4