Abstract:
Disclosed is an actuator device for remotely engaging, in fail-safe fashion, the slip segments on a slip-type elevator used in connection with a drill pipe, casing, or other object being lowered into or pulled out an oil, gas, geothermal, water, mining or other subsurface well. An actuator drive mechanism is provided and capable of extending a cylinder to engage the top surface of a slip segment or slip setting plate to cause the slips to be pushed into gripping engagement against the outer surface of the drill pipe, casing, or other object. The slips may be equipped with retention springs to move the slips back to their non-engaged positions when the actuator drive is disengaged or to urge continued engagement. The actuator drive cylinder can also be directly attached to the slips or slip setting plate and is capable of moving the slips into and out of their engaged position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the filing date of and priority to U.S. Provisional Application Ser. No. 62/209,327 entitled “Actuator, Elevator with Actuator, and Methods of Use” and filed Aug. 24, 2015, Confirmation No. 6697; said provisional application being incorporated by reference herein in its entirety for all purposes. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
     Field of the Invention 
       [0003]    The present disclosure relates generally to the field of oil, gas, geothermal, water, mining or other subsurface wells, and more particularly to the field of slip-type elevators used in connection with these wells. 
         [0004]    With slip-type elevators, the slips are designed to be movable between a static, non-engaged first position away from an outer surface of a drill pipe, casing, or other cylindrical object being lowered into or pulled out from the well to a second position in gripping engagement with the outer surface of the drill pipe, casing, or other cylindrical object being lowered into the well. 
         [0005]    Currently, setting a slip on a slip-type elevator requires that there be a physical device attached to the object being lowered or pulled out of the well. For example, a collar on a pipe being lowered into or pulled from a well is employed to physically interact with a setting plate located above the slip segments in the elevator to move the slips into engagement with the surface of the object in the elevator central slip bore to thereby hold the object in place. When the slip segments are moved into their engagement position, such movement also causes compression of the slip springs in the slip segments. When the collar is moved away from the slip segments, the action of the slip springs moves the slip segments back to their original, non-engaged position. 
         [0006]    However, the object being lowered into or pulled from a well, e.g., drill pipe, does not always have such collar structure capable of interacting with the slip setting plate (e.g., flush pipe). In these situations, the current practice is to temporarily attach a tool string member to the, e.g., drill pipe, so that the attached member can engage the slip setting plate. However, this is a time consuming process and a mechanical failure of this attached member can cause loss of the object (e.g., drilling string) down the well. 
         [0007]    Additionally, operators moving objects through an elevator desire to be able to close the elevator grips around the object at a desired location. However, existing elevator slip mechanisms do not permit the operator to, e.g., set drilling pipe at a desired, chosen location. 
         [0008]    Additionally, when a drill string or other object is being moved through an elevator, the drill string can encounter a bump or other resistance to movement that can cause the drill string or other object being gripped in the elevator slips to start bouncing. Existing elevators employ slips that must be mechanically engaged. Therefore, when this bouncing begins, when the tubing string bounces upward, the slips disengage and the existing elevator designs cannot reset the slips because there will not be present the required mechanical mechanism for triggering the closure of the slips. As a consequence, the bouncing or ratcheting of the drill pipe (or other object) permits the drill string to advance downwardly into the well in an uncontrollable fashion which can result in the tubing string (drill pipe) being lost down the well. 
         [0009]    Therefore, there remains a need for a slip type elevator actuator that is not required to be attached to the tubing string being lowered into or pulled from the well. There also remains a need for an elevator slip setting device that permits the operator to set the slips at any desired location along the outer diameter of the drill pipe or other object being moved through the elevator. There further remains a need for a method for preventing or mitigating the effects of ratcheting where the tubing string experiences an induced movement of load and for providing an elevator slip design that prevents or mitigates a ratcheting event that permits the tubing string to be dropped down the well. 
       BRIEF SUMMARY OF INVENTION 
       [0010]    In one embodiment there is disclosed and shown an actuator mechanism for actuating, as desired, one or more slip segments in a slip-type elevator used in connection with an oil, gas, geothermal, water, mining or other subsurface well, the elevator comprising a central slip bore between the slip segments permitting the passage therethrough of a drill pipe, casing, or other object being lowered into or pulled out of the well, the one or more slips capable of being actuated on a slip actuation surface to move between a static, non-engaged first position away from an outer surface of the drill pipe, casing, or other cylindrical object being lowered into or pulled out from the well to a second position in gripping engagement with the outer surface of the drill pipe, casing, or other object being lowered into or pulled out of the well. 
         [0011]    In one embodiment, the actuator mechanism comprises a mounting flange attachable to the elevator, a housing attached to the mounting flange, the housing positioned so that it does not extend into the elevator central slip bore, an actuator drive mechanism mounted within the housing, and a retractable piston extending from the actuator drive mechanism, the piston having a proximal end attached to the actuator drive mechanism and a distal end extendable therefrom. The actuator drive mechanism is capable of being activated to engage the piston with the slip actuation surface. The actuator drive mechanism is also capable of being activated to cause the piston to extend outwardly in engagement with the slip actuation surface to move the slips from the slip static, non-engaged first position into the slip second position to grippingly engage the outer surface of the drill pipe, casing, or other object, such as for example, a wireline. The actuator drive mechanism is also capable of maintaining the piston in its extended position to maintain the slips in such grippingly engaging position. The actuator drive mechanism is further capable of being deactivated to move the slips from the slip engaged second position to the slip disengaged first position. 
         [0012]    The actuator mechanism can be employed with various elevators, such as a floor spider type elevator or a lifting and hoisting type elevator or the like. The actuator mechanism may be activated hydraulically, pneumatically, magnetically, mechanically and/or electromechanically (such as with an electrical motor). 
         [0013]    In another embodiment, the actuator mechanism may further comprise at least one additional actuator device mounted in a housing attached to the mounting flange in spaced apart relationship from the other one or more actuator devices. These one or more actuator devices can be mounted in the same housing in spaced-apart relationship. 
         [0014]    In one embodiment, the slip activation surface comprises the top surfaces of the one or more slips. The elevator may further comprise a slip setting plate that links together the movement of the one or more slips, and the slip activation surface may comprise a top surface of the slip setting plate. 
         [0015]    In another embodiment of the actuator mechanism, the one or more slip segments comprise spring-loaded slip segments. The actuated movement of the one or more spring-loaded slips to their second positions causes the one or more springs in the one or more slips to be compressed. When the actuator is deactivated, the actuator piston is permitted to retract, and the one or more compressed springs in the one or more slips urge the one or more slips to return to their non-engaged first positions. 
         [0016]    In another embodiment of the actuator mechanism, the distal end of the retractable piston is attached directly to a point of attachment on the slip actuation surface. As the piston is engaged to extend outwardly, the one or more slips are pushed into their second positions. The actuator piston is capable of being held in its extended position to maintain the one or more slips in their second, engaged positions. As the piston is retracted inwardly, the one or more slips are pulled into their first positions. In this embodiment, the piston may be fixably, hingably, swivelly or flexibly attached to the point of attachment on the slip actuation surface. In another embodiment of this actuator mechanism, the one or more slips further comprise one or more pretensioned springs biased to provide a force urging the one or more slips into their second, engaged positions. As the piston extends outwardly, the one or more slips are pushed into their second positions assisted by the force of the one or more pretensioned springs. As the piston is retracted inwardly, the one or more slips are pulled into their first positions, and the one or more springs are compressed into their pretensioned bias. When the piston is holding the one or more slips in their second, engaged positions, the pretensioned springs serve as a fail-safe to maintain the one or more slips in their engaged positions in the event that the piston becomes detached from the point of attachment on the slip actuation surface. 
         [0017]    In another embodiment there is disclosed an actuator mechanism for actuating, as desired, one or more spring-loaded slip segments in a slip-type elevator used in connection with, e.g., a subsurface well, the elevator comprising a central slip bore between the slip segments permitting the passage therethrough of a drill pipe, casing, or other object being lowered into or pulled out of the well, the one or more spring-loaded slips capable of being actuated on a slip actuation surface to move between a static, non-engaged first position away from an outer surface of the drill pipe, casing, or other cylindrical object (such as, for example, a wireline) being lowered into or pulled out from the well to a second position in gripping engagement with the outer surface of the drill pipe, casing, or other object being lowered into or pulled out of the well, the movement of the slip to the second position causing the slip spring to compress and load the slip spring. 
         [0018]    In one embodiment, the actuator mechanism comprises a mounting flange attachable to the elevator; a housing attached to the mounting flange, the housing positioned so that it does not extend into the elevator central slip bore; an actuator drive mechanism mounted within the housing; a retractable piston extending from the actuator drive mechanism, the piston having a proximal end attached to the actuator drive mechanism and a distal end extendable therefrom. The actuator drive mechanism is capable of being activated to place the piston into contact with the slip actuation surface. The actuator drive mechanism is also capable of being activated to cause the piston to extend outwardly to push against the slip actuation surface to move the slips from the slip static, non-engaged first position into the slip second position to grippingly engage the outer surface of the drill pipe, casing, or other object while also compressing the slip springs. The actuator drive mechanism is also capable of maintaining the piston in its extended position to maintain the slips in such grippingly engaging position. The actuator drive mechanism being further capable of being deactivated to permit the compressed slip springs to move the slips from the slip engaged second position to the slip disengaged first position. 
         [0019]    The actuator mechanism can operate with various elevators, such as, for example, a floor spider elevator, a lifting or a hoisting elevator. 
         [0020]    The actuator mechanism can be driven in many ways. For example, hydraulically, pneumatically, magnetically, mechanically and electro mechanically, e.g., with an electrical motor. 
         [0021]    In another embodiment, the actuator mechanism further comprises at least one additional actuator device mounted in a housing attached to the mounting flange in spaced apart relationship from the other one or more actuator devices. For example, the multi-actuator system may employ two or more actuator drives to move the slips or slip setting plate. The actuator drives may be mounted in separate housings or share a common housing. The actuator drives can also be integrated directly into the body of the elevator. 
         [0022]    Also disclosed is slip-type elevator modified to include by way of retrofit or by way of specific design, one or more actuator devices as described herein. These slip-type elevators typically comprise: (a) a main body with a central elevator bore, (b) a plurality of slip segments mounted on slip guide pins spaced about the central elevator bore, the pins guiding the downward and upward movement of the slip segments about the elevator central bore, the slip segments capable of being actuated on a slip actuation surface to move between a static, non-engaged first position away from the outer surface of the drill pipe, casing, or other object being lowered into or pulled out from the well to a second position in gripping engagement with the outer surface of the drill pipe, casing, or other cylindrical object being lowered into or pulled out of the well, (c) a central slip bore between the slip segments permitting the passage therethrough of a drill pipe, casing, or other cylindrical object being lowered into or pulled out of the well, and (d) at least one actuator mechanism (as described herein) mounted to the elevator in a location that does not interfere with the desired passage of the drill pipe, casing, or other cylindrical object through the central slip bore. 
         [0023]    The slip-type elevators can include elevators wherein the main body is a hinged body, a solid body with a side door, or a solid body. 
         [0024]    The slip-type elevators can include for example, a floor spider elevator, a lifting or a hoisting elevator. 
         [0025]    The slip-type elevator may further comprise at least one additional actuator device mounted in a housing attached to the mounting flange in spaced apart relationship from the other one or more actuator devices. The one or more actuator devices may be mounted in the same housing in spaced-apart relationship. 
         [0026]    The slip activation surface may comprise the top surfaces of the one or more slips. In another embodiment, the elevator may further comprise a slip setting plate that links together the movement of the one or more slips. In this embodiment, the slip activation surface may comprise a top surface of the slip setting plate. 
         [0027]    In another embodiment of the slip-type elevator, the one or more slip segments comprise spring-loaded slip segments. In this embodiment, the actuated movement of the one or more spring-loaded slips to their second positions causes the one or more springs in the one or more slips to be compressed. When the actuator is deactivated, the actuator piston is permitted to retract, and the one or more compressed springs in the one or more slips urge the one or more slips to return to their non-engaged first positions. 
         [0028]    The slip-type elevator can further comprise slip segments that have retention springs located on the slip pins, the movement of the slip segments into the second position causing the slip retention springs to compress and load the slip retention springs, the compressed slip springs capable of moving the slips from the slip engaged second position to the slip disengaged first position. 
         [0029]    In yet another embodiment of the slip-type elevator, the slip segments comprise retention springs located on the slip pin. As the slip segments are moved into the second position, the slip retention springs become compressed. The compressed slip springs are capable of moving the slips from the slip engaged second position to the slip disengaged first position. 
         [0030]    In still another embodiment of the slip-type elevator, the distal end of the retractable piston is attached directly to a point of attachment on the slip actuation surface. As the piston is engaged to extend outwardly, the one or more slips are pushed into their second positions. The actuator piston is capable of being held in its extended position to maintain the one or more slips in their second, engaged positions. As the piston is retracted inwardly, the one or more slips are pulled into their first positions. In this embodiment, the piston may fixably, hingably, swivelly or flexibly attached to the point of attachment on the slip actuation surface. In another embodiment, the one or more slips further comprise one or more pretensioned springs biased to provide a force urging the one or more slips into their second, engaged positions. As the piston extends outwardly, the one or more slips are pushed into their second positions assisted by the force of the one or more pretensioned springs. As the piston is retracted inwardly, the one or more slips are pulled into their first positions, and the one or more springs are compressed into their pretensioned bias. When the piston is holding the one or more slips in their second, engaged positions, the pretensioned springs serve as a fail-safe to maintain the one or more slips in their engaged positions in the event that the piston becomes detached from the point of attachment on the slip actuation surface. 
         [0031]    Also described is a method of gripping and holding a drill pipe, casing, or other cylindrical object being lowered into or pulled out of an oil, gas, geothermal, water, mining or other subsurface well comprising the steps of: (1) providing a slip-type elevator as described herein; (2) activating the actuator mechanism; (3) remotely signaling the actuator drive to move the slip segments into gripping engagement with the outer surface of the drill pipe, casing, or other cylindrical object; (4) maintaining the slip segments in the gripping engagement for a desired length of time; and (5) deactivating the actuator drive mechanism to permit the slip segments to return to their first, non-engaged positions. The method can also be employed to activate the slip segments to grippingly engage the outer surface of the drill pipe, casing, or other cylindrical object being lowered into or pulled out of the well to prevent or mitigate a ratcheting event. The actuator mechanism may be activated hydraulically, pneumatically, magnetically, mechanically and/or electro-mechanically. Where multiple actuators are used to manipulate the slips, the actuators are coordinated to preferably move each respective slip substantially simultaneously. By employing the actuated slips of the present invention, positive pressure can be maintained on the slips to maintain them in their gripping position. Well operators can also set the slips around the objects at the location that they desire. 
     
    
     
       BRIEF SUMMARY OF DRAWINGS 
         [0032]      FIG. 1  is a front perspective view of an actuator mechanism according to an embodiment of the present disclosure. 
           [0033]      FIG. 2  is a front, exploded perspective view of an actuator mechanism according to an embodiment of the present disclosure. 
           [0034]      FIG. 3  depicts a front plan view of the actuator mechanism of  FIG. 1 . 
           [0035]      FIG. 4  depicts a back plan view of the actuator mechanism of  FIG. 1 . 
           [0036]      FIG. 5  depicts a top plan view of the actuator device of  FIG. 1 . 
           [0037]      FIG. 6  depicts a bottom plan view of the actuator device of  FIG. 1 . 
           [0038]      FIG. 7  depicts a left side plan view of the actuator mechanism of  FIG. 1 . 
           [0039]      FIG. 8  depicts a right side plan view of the actuator mechanism of  FIG. 1 . 
           [0040]      FIG. 9  depicts a left back perspective view of the actuator mechanism of  FIG. 1 . 
           [0041]      FIG. 10  depicts a right back perspective view of the actuator of  FIG. 1 . 
           [0042]      FIG. 11  depicts a left side perspective view of an exemplary elevator device further comprising the actuator mechanism of  FIG. 1  mounted thereon. 
           [0043]      FIG. 12  depicts a right side perspective view of the elevator device of  FIG. 11 . 
           [0044]      FIG. 13  depicts a top plan view of the elevator device of  FIG. 11  wherein the slip set of the elevator is in the engaged position by virtue of the engagement action of the actuator mechanism. 
           [0045]      FIG. 14  depicts a cross sectional left side plan view of the elevator device of  FIG. 11  taken along lines A-A of  FIG. 13 . 
           [0046]      FIG. 15  depicts enlarged Detail C taken from  FIG. 14 . 
           [0047]      FIG. 16  depicts a top plan view of the elevator device of  FIG. 11  wherein the slip set of the elevator is in the disengaged position. 
           [0048]      FIG. 17  depicts a cross sectional left side plan view of the elevator device of  FIG. 11  taken along lines B-B of  FIG. 16 . 
           [0049]      FIG. 18  depicts enlarged Detail D taken from  FIG. 17 . 
           [0050]      FIG. 19  depicts a cross sectional side plan view of the elevator device of  FIG. 11  taken along lines E-E of  FIG. 13 . 
           [0051]      FIG. 20  depicts enlarged Detail F taken from  FIG. 19 . 
           [0052]      FIG. 21  depicts a top partial cut-away view of the exemplary elevator of  FIG. 11  depicting one of the main body halves with one slip segment removed, and one slip segment shown in the non-engaged position (not compressing the spring) for purposes of illustration. 
           [0053]      FIG. 22  depicts a cross sectional view taken along lines G-G of  FIG. 21 . 
           [0054]      FIG. 22A  depicts enlarged Detail  22 A taken from  FIG. 22 . 
           [0055]      FIG. 23  depicts a top partial cut-away view of the exemplary elevator of  FIG. 11  depicting one of the main body halves with one slip segment removed, and one slip segment shown in the engaged position (compressing the spring) for purposes of illustration. 
           [0056]      FIG. 24  depicts a cross sectional view taken along lines H-H of  FIG. 23 . 
           [0057]      FIG. 24A  depicts enlarged Detail  24 A taken from  FIG. 24 . 
           [0058]      FIG. 25  depicts a top partial cut-away view of the exemplary elevator of  FIG. 11  depicting one of the main body halves with one slip segment removed, and one springless push-pull slip segment shown in the engaged position for purposes of illustration of another embodiment of the present disclosure. 
           [0059]      FIG. 26  depicts a cross sectional view taken along lines I-I of  FIG. 25 . 
           [0060]      FIG. 26A  depicts enlarged Detail  26 A taken from  FIG. 26 . 
           [0061]      FIG. 27  is a front perspective view of a multi-actuator mechanism (shown here as a dual actuator mechanism) according to another embodiment of the present disclosure. 
           [0062]      FIG. 28  depicts a back perspective view of the actuator mechanism of  FIG. 27 . 
           [0063]      FIG. 29  is a front, exploded perspective view of a multi-actuator mechanism (shown here as a dual actuator mechanism) according to another embodiment of the present disclosure. 
           [0064]      FIG. 30  depicts a front plan view of the actuator mechanism of  FIG. 27 . 
           [0065]      FIG. 31  depicts a back plan view of the actuator mechanism of  FIG. 27 . 
           [0066]      FIG. 32  depicts a top plan view of the actuator device of  FIG. 27 . 
           [0067]      FIG. 33  depicts a bottom plan view of the actuator device of  FIG. 27 . 
           [0068]      FIG. 34  depicts a left side plan view of the actuator mechanism of  FIG. 27 . 
           [0069]      FIG. 35  depicts a right side plan view of the actuator mechanism of  FIG. 27 . 
           [0070]      FIG. 36  depicts a top partial cut-away view of the exemplary elevator of  FIG. 11  depicting one of the main body halves with one slip segment removed, and one spring-assisted push-pull slip segment shown pulled up into the disengaged position for purposes of illustration of another embodiment of the present disclosure. 
           [0071]      FIG. 37  depicts a cross sectional view taken along lines J-J of  FIG. 36 . 
           [0072]      FIG. 37A  depicts an enlarged Detail  37 A taken from  FIG. 37  to illustrate the use of springs to provide fail-safe positive downward force on the slip. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0073]    One embodiment of the present disclosure pertains to an improved actuator mechanism  10  for use, e.g., in actuating the slips on a slip-type well drilling elevator  200 . Referring to  FIGS. 1-10  there is shown an exemplary single actuator mechanism  10  generally comprising: an outer housing  11 , an outer housing lower edge  12 , an actuator mount  13 , actuator mount apertures  13   a  for attaching the mount  13  to an actuator mechanism mounting plate  14 . If desired to increase the height of the underside of the housing  12  from the mounting plate bottom surface  15 , a mounting plate rise  14   a  can be employed. In this embodiment, the mounting plate further comprises mounting plate bolt holes  16  for mounting the actuator mechanism onto an elevator device  200 . The actuator mechanism  10  further comprises an actuator device  19  maintained within the housing. Bolts  23  or the like can be employed to attach the actuator device  19  within the housing  11 . The bolts can pass through apertures  23   a  and the secure to receiving nuts  23   b  or the like. In one embodiment, the actuator drives a retractable/extendable cylinder  20  downwardly toward the surface to be actuated. In this embodiment, the cylinder  20  further comprises at its distal end a cylinder push member  21  for exerting a force from the actuator onto an object. In another embodiment, the tip of the actuator push member  21  further comprises a push point  22  to provide a point source of force rather than a wide source of force. 
         [0074]    In one embodiment, the actuator mechanism extendable cylinder  20  is activated pneumatically. In this embodiment, a pressure source (e.g., pressurized air) is fed to the actuator mechanism through a suitable conduit/hose (not shown) and connected to the control line input  18  of the actuator mechanism. In this embodiment, there is also preferably a control panel (not shown) providing the operator with the ability to control the pressure of the pressurized air entering the actuator mechanism, and to also control when the pressure is to be applied (to extend the cylinder  20 ) or disengaged (where there is no air pressure attempting to move the cylinder to its extended position). Exemplary air actuators are available from Fabco Air (Houston, Tex.), and can operate in a number of ways, such as single action, single action spring return, or dual action extension and return. 
         [0075]    In another embodiment the actuator mechanism is activated hydraulically and would similarly have a pressurized hydraulic fluid introduced into the actuator mechanism inlet ( 18 ) via conduit (not shown), where the flow of the pressurized hydraulic fluid is preferably controlled by a control panel (not shown). 
         [0076]    In another embodiment, the actuator mechanism is activated mechanically, e.g., by operation of an electrical motor (not shown). The actuator mechanism could also be activated by operation of magnetic fields. 
         [0077]    The actuator housing could also be integrated directly into the mounting plate. 
         [0078]      FIGS. 11 and 12  illustrate one example type of slip style elevator device  200  that can employ the single-, or multi-actuator mechanisms  10 ,  110  described herein. Slip type elevators are well known in the art and generally comprise a two piece main body  202  attached by a hinge, handles  204 , and link blocks  206 . The elevator  200  also comprises a central bore containing slip segments  208 . The slip segments have an inner gripping surface  210 . The objects to be held by the slips pass through the elevator central slip bore  212 . 
         [0079]    Referring also to  FIGS. 13-26A , as will be appreciated, the actuator mechanism  10 ,  110  can be mounted on the elevator  200  in a fashion that permits the action of the actuator device to cause the slip segments  208  to be moved into engaging contact with the outer diameter  8  of the object located within the elevator central slip bore  212 . 
         [0080]    For example, referring specifically to  FIGS. 16-22A  there are depicted elevator slip segments  208  in their non-engaged positions. Here, the actuator mechanism  10  has been mounted on the outer perimeter of the elevator bore in a fashion that does not permit any of the actuator mechanism to extend into the elevator central slip bore  212 . In this embodiment, two of the slip segment guide pins  214  also serve as the bolts for bolting the actuator mechanism  10  to the top of the elevator through the actuator mechanism bolt holes  16 . In this embodiment, the actuator device mounting plate  14  is arc-shaped so that the lower surface  15  can mate easily with the upper surface of the elevator. However, other mounting configurations are possible. In operation, the actuator mechanism is mounted on the elevator proximate the top of the slip segments. The actuator extendable cylinder  20  is capable of moving the actuator cylinder push member  21  into contact with the top surface of a slip segment  208  (or the top surface of a slip setting plate  216 ). The actuator cylinder or piston  20  can then contact this slip actuation point to urge the slip into its engaged position. In this embodiment, a slip setting plate  208  is employed to tie together the movement of the slips, and the actuator cylinder push member  21  is aligned to press down onto the top surface of the setting plate  208 , in which case, a single slip actuation point can serve to move multiple slips. 
         [0081]    Typically, as is known in the art, the individual slip segments are interlocked together along their respective vertical edges in an interlocking channel (not shown). The interlock channel provides spacing between the vertical edges of the slip segments so that as the slip segments are urged into their downward/inward engaged positions, the slips will have sufficient downward and inward movement to grippingly engage the object. The interlock channels can also assist in urging adjacent slip members to move downward and inward as the adjacent slip member is moved downward. Likewise, use of a slip segment setting plate  216  can also be used to assist in moving multiple slip segments at the same time. 
         [0082]      FIGS. 21-22A  depict a typical spring-loaded slip  208  having at least one slip tab stop  220  in spaced relationship from a mechanical elevator slip stop  221 . As will be understood, the slip is mounted about the slip guide pin or bolt  214  in a fashion that permits the slip to move upward and downward along the pin  214 . A spring  218  is retained about the pin  214  and sits in a spring channel  222 . As the slip  208  is moved downward along the pin  214 , the spring  218  is compressed between upper slip spring stop  220  and the bottom of the spring retention channel  223 . 
         [0083]    Referring now to  FIGS. 13-15 and 23-24A  there are depicted elevator slip segments  208  in engaged positions against the outer diameter  8  of the object  6  to be held by the elevator  200 . The operator of the actuator will engage the actuator device  19  to urge the actuator cylinder  20  to extend outward (here, downward) to cause the push member to push downward on the top of the slip  208  or as depicted here, the top of the slip setting plate  216 . As the slip segments  208  are moved downward, the slip springs  218  are compressed between, e.g., the bottom of spring retention channel  223  and the underside of slip spring stop  220 . In one embodiment, the tip of the actuator push member  21  further comprises a push point  22  to provide a point source of force rather than a wide source of force to permit pushing the slip members downward along a path that is not axial with the path of the cylinder  20 . Once the slip segments are moved into engaged position, the slip gripping surfaces  210  then contact and grip the outer surface  8  of the object  6  to be held. The object  6  is then held by the slip gripping surface  210  for the desired length of time. To release the object from the grip of the slips  208 , the operator disengages the actuator drive  19  to remove the motive force exerted downward on the actuator cylinder  20 . In some actuator devices  19 , there exists a spring to push the cylinder back to its retracted position. In other actuator devices  19 , there is a mechanism that drives the cylinder in both directions, in which case, the operator would move the cylinder by engaging actuator  19  to either operate in the extension or retraction direction. Once the cylinder  20  is retracted, in the typical elevator that employs spring-mounted slip segments  208 , the slip segments  208  will be urged back to their original disengaged positions by virtue of the action of the compressed springs  218  pushing the slips back upward. The force of the springs can also cause the upward movement of the slips  208  to push the cylinder  21  back into its housing. 
         [0084]    Referring now to  FIGS. 25-26A , there is depicted another elevator slip segment arrangement (similar to that in the previous Figures). However, in this embodiment, the slip segments  208  are not spring loaded. Instead, the cylinder  20  of the actuator device  19  is directly connected to the top of the slip segment  208  or slip setting plate  216  via a hinged and/or swivel connection generally depicted here as the tab  224  fixed to the top of the slip or slip setting plate and provided with an attachment point  226  for attaching to the distal end of the cylinder  20 . As will be understood by those having the benefit of the present disclosure, the method of attachment of the actuator piston mechanism  20  to the slip attachment point  226  may be achieved in any number of ways known in the art, including, swivel connections, hinged connections, ball connections, fixed connections, rigid connections and flexible connections. In this embodiment, the actuator drive  19  is designed to push the cylinder  20  downward to engage the slips  208  against the outer surface  8  of the object  6  to be held, and to pull the cylinder  20  back upward to disengage the slips  208 . This push-pull configuration can be achieved with any number of actuator drive mechanisms  19  suitably coupled to the slips or slip setting plate. For example, and without limitation, the push-pull actuator could be a hydraulically or pneumatically driven system move the slip between its disengaged and engaged positions. Additionally, the push-pull actuator could be mechanically or magnetically driven. In one example, the actuator is electrically driven, such as by an electric motor with screw drive assembly, or via a solenoid mechanism. Although this embodiment describes pushing the slips into their engaged positions, and pulling the slips back to their original position, other configurations are possible such as a pull-push configuration where the slips are pulled into their engaged positions and are pushed back to their disengaged positions. 
         [0085]    Referring now to  FIGS. 36-37A , there is shown another push-pull embodiment similar to that described in connection with  FIGS. 25-26A , modified to include slip springs  218   a  positioned along slip guide pin  214  between spring/slip stop  220   a  and the top  223   a  of spring retention channel  222  (also referred to as the elevator slip stop  221 ) to provide pre-loaded constant downward positive force on the slip  208   a  so that the slip is always urged towards its engaged position. This downward spring force augments the downward force provided by the push-pull actuator mechanism (e.g., hydraulic, pneumatic or electrical actuators). In addition to the force of spring  218   a  providing downward push force assistance to the actuator, it also serves as a fail-safe in the event of a failure of the actuator to hold the slip in the downward position. This fail-safe mechanism guards against the unexpected release of the tubing or other object  6  being held by the slips in the elevator in the event of an actuator failure. For example, if a hydraulic or pneumatic hydraulic fluid or air-line to the actuator is accidently cut, or there is a power failure with an electrical actuator, the downward spring force will maintain the slips in their engaged position. In this embodiment, the actuator is designed with sufficient pulling force to pull the slip back upwards to its disengaged position against the force of the spring  218   a.    
         [0086]    Although the above-described embodiments depict just one actuator drive  19  (housed in housing  11 ) being employed, it will be appreciated that multiple actuator drives  19  could be employed in similar fashion to provide the desired total downward pushing force required to move the slip segments. An exemplary multi-actuator actuator mechanism is depicted in  FIGS. 27-35  discussed below. 
         [0087]    Referring now to  FIGS. 27-35 , there is shown an exemplary multi-actuator, actuator mechanism  110 . The actuator devices  19  are similar to those previously described, and also fit within similar housing  111 . In this embodiment, the actuator device  19  is secured within the housing  111  by use of a retention ring  112 . The housing also comprises a housing mount  113  for mounting the actuator device to a mounting plate  114 . The housing  111  could also be integral, or of unitary construction, with the mounting plate  114 . The underside of the mounting plate  115  can be mated with a mounting surface proximate the elevator central bore (not shown). In this particular embodiment, the mounting plate may also be elevated to a desired height by employing mounting plate height spacers  114   c,  here, shown as cylindrical tubes that sit beneath the bolt holes  116 . In this embodiment, there are shown two actuator devices  19  being mounted in space relationship from each other. In this embodiment, the respective actuator devices can deploy extendable cylinders  20  to contact and push upon the top surfaces of the slip segments or slip setting plate. The use of multiple actuators can provide for the additional force that may be required to push the slips downward into engaged position. 
         [0088]    As will be understood by those having the benefit of the present disclosure, each actuator mechanism will be remotely controllable by a well operator. For example, each actuator mechanism will be tied into an actuator control line input  18 . In the pneumatic actuator device embodiments, a pneumatic hose (not shown) will be connected to the actuator device(s)  19  via this control line input  18 . The pneumatic line will extend to a control box (not shown) where an operator can control the engagement and disengagement of the actuator and control the air pressure into the line. In one embodiment, the source of pneumatic pressure is provided onsite by the wellbore pressure and is passed through a pressure regulator to permit regulation of the pressure. In similar fashion, in the hydraulic actuator device embodiments, a hydraulic hose (not shown) will be connected to the actuator device(s)  19  via this control line input  18 . The hydraulic line will extend to a control box (not shown) where an operator can control the engagement of the actuator and control the fluid pressure into the line. Likewise, where operational conditions permit, the actuator device can be mechanical and be driven electrically by feeding a source of electricity to the actuator device  19  via the control line input  18 . 
         [0089]    It will also be understood by those having the benefit of the present disclosure that other embodiments are possible within the spirit and scope of the present disclosure. For example, although the above embodiments have illustrated an actuator mechanism  10 ,  110  being a separate device attachable about the top edge of the elevator central bore, other attachment configurations are possible. For example, the actuator mechanism could be mounted on the outside face of the elevator body  202  and configured to orient a push cylinder  20  in position to push downwardly on the slip segments or slip setting plate. 
         [0090]    The actuator housing could also be integrated directly into the mounting plate. 
         [0091]    Alternatively, although the actuator mechanism has been described as a device that is separately connectable to the elevator, it will also be understood by those having the benefit of the present disclosure that the actuation mechanism could be built into the elevator itself. For example, the actuator device(s) could be built into the main wall of the actuator and have cylinder member(s) oriented to direct the movement of the slip segments. 
         [0092]    Also, although the Figures depict an elevator  200  employing a setting plate, the slips can be moved directly via the action of the actuator without the need for a setting plate. 
         [0093]    The actuator device of the present disclosure provides a fail-safe mechanism for securing the object in the central slip bore. Even in the event of a mechanical slipping of the pipe (as may be caused by sudden weight lode being exerted on the tubing string), even if the pipe string bounces upward, the slips will be temporarily disengaged when the upward force pushes the slips back into their disengaged positions, but when the pipe then heads back downward, the slips will automatically engage and again grip the pipe thereby preventing the pipe from being lost down the well. 
         [0094]    All references referred to herein are incorporated herein by reference. While the apparatus, systems and methods of this invention have been described in terms of preferred or illustrative embodiments, it will be apparent to those of skill in the art that variations may be applied to the process and system described herein without departing from the concept and scope of the invention. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the scope and concept of the invention. Those skilled in the art will recognize that the method and apparatus of the present invention has many applications, and that the present invention is not limited to the representative examples disclosed herein. Moreover, the scope of the present invention covers conventionally known variations and modifications to the system components described herein, as would be known by those skilled in the art.