Abstract:
The present invention discloses an automatic drill floor to substructure latching system that adds to the safety of drilling operations. In particular, the present invention is applicable for rapid and safe locked connection of a drilling rig side box to the drilling rig base box such that weight imbalances incurred when raising of the drilling rig mast will not result in unsecured and unsafe separation of the side box and base box.

Description:
TECHNICAL FIELD OF INVENTION 
     The embodiments of the present invention relate to a novel mechanism that adds to the safety of drilling operations. In particular, the present invention is applicable for rapid and safe locking of a drilling rig substructure side box to the drilling rig base box such that the raising of the drilling rig mast will not result in unsecured and unsafe separation during mast raising and lowering. 
     BACKGROUND OF THE INVENTION 
     In the exploration of oil, gas and geothermal energy, drilling operations are used to create boreholes, or wells, in the earth. Drilling rigs used in subterranean exploration must be transported to the locations where drilling activity is to be commenced. These locations are often remotely located in rough terrain. The transportation of such rigs on state highways requires compliance with highway safety laws and clearance underneath bridges or inside tunnels. Once transported to the desired location, large rig components must each be moved from a transport trailer into engagement with the other components located on the drilling pad. 
     Moving a full-size rig requires disassembly and reassembly of the substructure and mast. Safety is of paramount importance. Speed of disassembly and reassembly is also critical to profitability. Complete disassembly leads to errors and delay in reassembly. When the substructure is assembled over the drilling pad, the mast is connected to the drill floor above the substructure. Each substructure side box is pin connected to its respective substructure base box. The drill floor center section is connected between the driller&#39;s side box and the off-driller&#39;s side box. The lower section of the mast is pin connected to the drill floor. The center mast section is pin connected to the lower mast section and the upper mast section is connected to the center mast section. 
     When the mast sections are connected together, the mast is raised by pivoting it on the pin connection to the drill floor. It is critical that the driller&#39;s side boxes remain secured to the base boxes during mast raising. Failing to properly secure them together results in their separation and collapse of the mast with significant damage to the entire structure and risk of injury or death to personnel. Once the mast has been raised over the drill floor, the side boxes are unpinned to disconnect then from the base boxes. Only then can the substructure can be raised. 
     It is desirable to have a connection system that is automated, to reduce rig-up and rig-down time. It is desirable to have a system that can be manually unlatched, and that automatically resets itself upon substructure raising. It is also desirable to have a system that latches automatically to speed the operation and to prevent accidents when an employee forgets to pin the side box to the base box. It is also desirable that the connection and disconnections be performed without the need to align the dog-ears (pin holes) for insertion of a pin. 
     More particularly, it is desirable to provide a substructure lock mechanism that cannot be left open when the side box is away. It is also desirable to provide a substructure lock mechanism that will automatically reset itself in a fairly short distance of raising the side box above the base box, such that if necessary to bring the side box back down for any reason during raising, the lock mechanism will re-engage. 
     The preferred embodiments of the present invention provide a unique solution to the engineering constraints and challenges of providing a rapid, safe, and reliable connection between the drill floor and substructure of a drilling rig. 
     SUMMARY OF THE INVENTION 
     The present invention provides a mechanism for automatic and secure connection of the side box of a drilling rig substructure to the base box of the drilling rig substructure, as well as rapid release, reset, and self-alignment. The substructure lock system provided requires the weight of the side box to keep the latch open, where upon separation of the side box from the base box, the latch automatically resets itself. 
     The lock system comprises a strike affixed to a bottom side of a side box portion of a drilling rig substructure. The substructure lock mechanism is affixed to a top side of a base box portion of the drilling rig substructure. The substructure lock mechanism comprises a housing and a latch pivotally connected to the housing and retractable to an open position and extendable to a closed position. A spring assembly in the housing urges the latch into the closed position. The latch is forceably retracted by engagement with the strike when the side box is moved towards engagement with the base box. 
     The spring assembly urges the latch back into the closed position over the strike when the side box is engaged with the base box, thus latching the side box to the base box. 
     A release is connected to the housing and linkage connected to the spring assembly and the latch. The release is manually movable from a disengaged position to an engaged position. In the engaged position, the release compresses the spring assembly and retracts the latch, moving it from the closed position to the open position. With the latch in the open position, the strike is released, permitting separation of the side box from the base box. 
     A reset is also connected to the housing, and may have a reset paddle that is engageable with the bottom side of the side box. When the side box is moved towards the base box, the side box pushes the reset paddle into the compressed position. When the side box moves away from the base box, the side box releases the reset paddle, moving it to an uncompressed position. The uncompressed reset operably moves the engaged release into the disengaged position, causing the latch to return to the closed position by operation of the spring assembly. This occurs automatically when the side box moves away from engagement with the base box and the reset paddle. 
     As will be understood by one of ordinary skill in the art, the assembly disclosed may be modified and the same advantageous result obtained. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of one embodiment of the substructure lock mechanism of the present invention, illustrating the lock mechanism in the receive position. In this position, the latch is in the closed position, the release in the unengaged position, and the reset in the uncompressed position. 
         FIG. 2  is an isometric view of the substructure lock mechanism of  FIG. 1 , illustrating the lock mechanism in the latched position. In this position, the latch is in the closed position, the release in the unengaged position, and the reset in the compressed position. 
         FIG. 3  is an isometric view of the substructure lock mechanism of  FIG. 1 , illustrating the lock mechanism in the release position. In the position, the latch is in the open position, the release in the engaged position, and the reset in the compressed position. 
         FIG. 4  is an isometric exploded view of the substructure lock mechanism of  FIGS. 1 through 3 . 
         FIG. 5  is an isometric view of an embodiment of the substructure lock mechanism of the present invention, illustrating the lock mechanism in the receive position, with the side box approaching the base box. 
         FIG. 6  is an isometric view of the substructure lock mechanism of  FIG. 5 , illustrating the strike of the substructure engaging the latch and forcibly retracting the latch. 
         FIG. 7  is an isometric view of the substructure lock mechanism of  FIG. 6 , illustrating the lock mechanism in the latched position, with the latch secured over the strike to lock the side box against the base box. 
         FIG. 8  is an isometric view of the substructure lock mechanism of  FIG. 7 , illustrating the lock mechanism in the release position, with the side box free to be raised above the base box, but still compressing the reset of the lock mechanism. 
         FIG. 9  is an isometric view of the drill floor to substructure lock mechanism of  FIG. 8 , illustrating the side box being raised up and away from the base box. 
         FIG. 10  is an isometric view of the substructure lock mechanism of  FIG. 9 , illustrating the side box raised above the base and fully disengaged from the lock mechanism, and the lock mechanism having returned itself to the receive position. 
         FIG. 11  is an isometric view of an alternative embodiment, illustrating complementary configuration of the substructure frame for receiving the substructure lock mechanism, and providing a reset strike for engaging the reset of the substructure lock mechanism. 
         FIG. 12  is a diagrammatic representation of the three static positions of the substructure lock mechanism of the present invention, and the coincident positions of the latch, release, and reset. 
     
    
    
     The objects and features of the invention will become more readily understood from the following detailed description and appended claims when read in conjunction with the accompanying drawings in which like numerals represent like elements. 
     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. 
       FIG. 1  is an isometric view of one embodiment of substructure lock  1  of the present invention, illustrated in the “receive” position. Substructure lock  1  has a housing  10 . As seen in  FIG. 5 , housing  10  is secured by welding, mechanical fasteners, or other means to a base box  102  of a drilling rig  100  (not fully shown or indicated). 
     A latch  20  is pivotally attached to housing  10  and is movable between a closed and open position. As seen in  FIG. 1 , when substructure lock  1  is in the receive position, latch  20  is in the closed position. In this position, latch  20  can receive a strike  112  extending from side box  110  (see  FIG. 5 ). Latch  20  will momentarily retract while receiving strike  112  (see  FIG. 6 ), and then automatically return to the closed position to prevent separation of side box  110  from base box  102  (see  FIGS. 2 and 7 ). 
     A release  30  is pivotally attached to housing  10  and is manually movable from a disengaged position to an engaged position. In  FIG. 1 , release  30  is illustrated in the disengaged position. In the engaged position (see  FIGS. 3 and 8 ), release  30  will cause substructure lock  1  to move into a “release” position in which latch  20  moves to the open position. In the release position, side box  110  may be removed from engagement with base box  102  (see  FIGS. 3 and 9 ). 
     A reset  40  is pivotally attached to housing  10 . Reset  40  is movable between an uncompressed position and a compressed position. In  FIG. 1 , reset  40  is illustrated in the uncompressed position. Movement of reset  40  between the uncompressed and compressed positions is caused by engagement of reset  40  with side box  110  of a drilling rig  100  (see  FIGS. 5-7 ). Movement of reset  40  from a compressed position to an uncompressed position causes release  30  to move from the engaged position to the disengaged position (see  FIG. 10 ). 
       FIG. 2  is an isometric view of substructure lock  1  of  FIG. 1 , illustrated with latch  20  in the latched position, release  30  in the unengaged position, and reset  40  in the compressed position. In this configuration, lock mechanism  1  has received strike  112  and is securing side box  110  to base box  102  (see  FIG. 7 ). 
     In the embodiment illustrated, as side box  110  approaches base box  102 , strike  112  engages a cam  22  of latch  20 . Cam  22  is angularly disposed to cause rotation of latch  20  relative to housing  10 . As strike  112  passes cam  22 , a spring assembly  60  (see  FIG. 4 ) urges latch  20  to return to the engaged position. In the embodiment illustrated, as latch  20  returns to the engaged position, a hook  24  portion of latch  20  extends over strike  112  of side box  110  to secure it in place against base box  102 . 
       FIG. 3  is an isometric view of substructure lock  1  of  FIGS. 1 and 2 , illustrated with latch  20  in the unlatched position, release  30  in the engaged position, and reset  40  in the compressed position. In this configuration, release  30  has been manually moved into the engaged position, retracting latch  20  to allow side box  110  to be removed from engagement from base box  102 . However, side box  110  has not yet been removed from engagement from base box  102 , as it continues to hold reset  40  in the compressed position (see  FIG. 8 ). 
       FIG. 4  is an isometric exploded view of substructure lock  1 . As seen in  FIG. 4 , latch  20  has a cam surface  22  and a hook  24 . A latch pin  26  pivotally connects latch  20  to housing  10 . A latch link  28  is pivotally connected between latch  20  and a spring rod  70 . Spring rod  70  articulates laterally in a slot  14  on housing  10 . 
     Release  30  has a release lever  32  pivotally connected to housing  10  on a lever pin  34 . In the embodiment illustrated, a key slot  33  is located on release lever  32  proximate to its pivotal connection to lever pin  34 . 
     A release lock  36  is pivotally connected to housing  10  by a reset pin  50 , and movable between a locked position and an unlocked position. Release lock  36  has a lock hook  37  engageable with key slot  33  on lever  32 , to lock release lever  32  in the engaged position. 
     A release linkage  38  connects release lever  32  to spring rod  70 . Release linkage  38  translates force from rotational movement of release lever  32  to horizontal movement of spring rod  70  in slot  14 . At the same time, latch link  28  translates the resultant horizontal movement of spring rod  70  into retraction of latch  20 . Conversely, engagement of strike  112  with latch  20  forces rotation of latch  20  and through latch link  28 . 
     Reset  40  has a reset lever  42  pivotally connected to housing  10  on reset pin  50 . A reset paddle  46  extends from reset lever  42  for engagement with side box  110  or alternatively to a reset strike bar  114  extending from side box  110 . A reset spring  48  urges reset  40  into the uncompressed position, which causes release  30  to move from the engaged position to the disengaged position. 
     A reset pin  43  transmits rotation of reset lever  42  to release lock  36 . By this connection, movement of reset  40  from the compressed position to the uncompressed position disengages release lock  36  from key slot  33 , allowing spring assembly  60  to push release  30  into the disengaged position and latch  20  into the closed position. 
     Spring assembly  60  has one or more springs  62 . In the illustrated embodiment, springs  62  are partially positioned inside spring sleeves  64 . A spring block  12  in housing  10  has apertures for receiving sleeves  64  in sliding relation. Sleeves  64  are pin connected to spring rod  70  at one end of springs  62 . The opposite end of springs  62  are abutted to an end cap  68  that secures them in place inside spring block  12  of housing  10 . 
     Also in the embodiment illustrated, a visible indicator  66  is located in spring block  12  in sliding relation. In the embodiment illustrated, indicator  66  is connected to spring rod  70  such that if spring rod  70  is forced towards end cap  68 , compressing spring assembly  60 , indicator  66  extends beyond end cap  68 , alerting crew members that substructure lock  1  is in the release position, and side box  110  is not latched to base box  102 . 
     Manual downward movement of release lever  30  into the engaged position compresses spring assembly  60 , and moves latch  20  into the open position. The downward force on release lever  30  is necessary until the point is reached in which release lock  36  engages key slot  33  on lever  32  to lock release lever  32  in the engaged position. The weight of side box  110  on reset  40  keeps release lock  36  engaged with key slot  33 . 
       FIG. 5  is an isometric view of the embodiment of substructure lock  1 , illustrated in the same position as in  FIG. 1 , and shown mounted on base box  102 . For example, substructure lock  1  may be mounted on the centerline of the upper beam of base box  102 . Referring ahead to  FIG. 12 , this is the receive position of substructure lock  1 , in which latch  20  is closed, release  30  is disengaged, and reset  40  is uncompressed. In this view, side box  110  is approaching base box  102 , and substructure lock  1  is ready to receive side box  110 . 
       FIG. 6  is an isometric view of the embodiment of substructure lock  1  illustrated in  FIG. 5 , showing strike  112  of side box  110  engaging cam surface  22  of latch  20 , and forcibly retracting latch  20 . Referring to  FIG. 4 , forced retraction of latch  20  compresses spring assembly  60 , and momentarily moves release  30  towards the engaged position until strike  112  passes cam surface  22  of latch  20 . At that point, spring assembly  60  urges latch  20  into the closed position as the hook portion of latch  20  captures strike  112 , allowing release  30  to return to the unengaged position. As substructure  110  progresses downward, some portion of substructure  110 , such as substructure frame  114  or a reset strike  116  ( FIG. 11 ) extending from it, engages reset  40 , moving it from the uncompressed position to the compressed position. 
       FIG. 7  is an isometric view of the embodiment of substructure lock  1  illustrated in the same position as in  FIG. 2 , now shown mounted on base box  102 . Referring ahead to  FIG. 12 , this is the latched position of substructure lock  1 , in which latch  20  is closed, release  30  is disengaged, and reset  40  is compressed. In this view, side box  110  is resting on base box  102 . Substructure lock  1  is latched over strike  112  of side box  110 , safely securing it in place, so as to prevent errant separation of side box  110  from base box  102  during mast raising or transport. 
       FIG. 8  is an isometric view of the embodiment of substructure lock  1  illustrated in the same position as in  FIG. 3 , now shown mounted on base box  102 . Referring ahead to  FIG. 12 , this is the release position of substructure lock  1 , in which latch  20  is open, release  30  is engaged, and reset  40  remains compressed. In this view, side box  110  is still resting on base box  102  and thus compressing reset  40 . Release  30  has been manually pulled into the engaged position. Alternatively, release  30  is otherwise intentionally moved, such as by hydraulic and/or electronic control. Referring to  FIG. 4 , engagement of release  30  compresses spring assembly  60  and moves latch  20  into the open position. In this position, side box  110  may be separated from base box  102  to raise substructure  110 . 
       FIG. 9  is an isometric view of the embodiment of substructure lock  1 , illustrated in  FIG. 8 , illustrating side box  110  beginning to rise up from engagement with base box  102 . In this view, substructure  110  continues to provide force on reset  40  until strike  112  has moved out from the possible grasp of hook  24  of latch  20  (see  FIGS. 3 and 4 ). 
       FIG. 10  is an isometric view of the drill floor to substructure connection system of  FIG. 9 , illustrating side box  110  continuing to rise away from base box  102  and now fully disengaged from reset  40  of substructure lock  1 , allowing it to move to the uncompressed position as may be urged by reset spring  48  ( FIG. 4 ). As reset lever  42  raises up, release lock  36  rotates from the locked position to the unlocked position, in which lock hook  37  disengages key slot  33  on lever  32 . This causes release  30  to pivot out of the engaged position and into the disengaged position automatically upon movement of side box  110  away from base box  102 . As a result, substructure lock  1 , as illustrated in  FIG. 10 , has returned to the receive position as illustrated in  FIGS. 1 and 5 . 
     As described, the only physical interface the drilling crew has with substructure lock  1  is to manually move it (or with fitted hydraulic and/or electronic controls) into the release position for raising side box  110  of drilling rig  100 . Advantageously, there is no other interface needed between the drilling crew and substructure lock  1 . A further advantage is that substructure lock  1  automatically and immediately returns to the receive position upon separation of side box  110  from base box  102 . If unforeseen circumstances require the immediate lowering of side box  110  back onto base box  102 , substructure lock  1  will be ready to again receive and secure side box  102  from the moment side box  110  is disengaged from substructure lock  1 . 
       FIG. 11  is an isometric view of an alternative embodiment, illustrating a complementary configuration of substructure  110  framework for engaging substructure lock  1 . In a first alternative embodiment, one or more recesses  118  are formed on side box  110  to provide clearance for unencumbered operation of latch  20 . 
     In a second alternative embodiment, side box  110  is modified to provide controlled engagement with reset  40 . In this embodiment, a reset strike bar  116  extends from side box  110  for complementary engagement with reset paddle  46  of reset  40 . 
     In another alternative embodiment, latch  20  has a viewport through which strike  112  is viewable when lock mechanism  1  is in the latched position. By this means, crew members can easily verify that side box  110  is properly locked to base box  102 . 
       FIG. 12  is a diagrammatic representation of the three static positions of substructure lock  1 , and the relative positions of latch  20 , release  30 , and reset  40 . The embodiment thus described provides a substructure lock  1  designed for sustained configuration in three positions. Importantly, the described embodiment discloses a substructure lock  1  capable of self-positioning between two of the three positions, and requiring deliberate interaction to be moved into the third position (release position). 
     The first position of substructure lock  1  is a “Receive Position” in which substructure lock  1  is ready to receive side box  110 . When substructure lock  1  receives side box  110 , it automatically snaps into its second position. 
     The second position is the “Latched Position” in which substructure lock  1  secures side box  110  to base box  102 . To release side box  110  from base box  102 , release  30  of substructure lock  1  must be manually engaged, placing substructure lock  1  in its third position. 
     The third position is the “Release Position” in which substructure lock  1  is unlatched from side box  110 , which may then be moved away from base box  102 . As side box  110  is moved away from base box  102 , substructure lock  1  automatically cycles back into position  1 , and is again ready to receive side box  110 . 
     As used herein, the term “substantially” is intended for construction as meaning “more so than not.” 
     Having thus described the present invention by reference to certain of its preferred embodiments, it is noted that the embodiments disclosed are illustrative rather than limiting in nature and that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present invention may be employed without a corresponding use of the other features. Many such variations and modifications may be considered desirable by those skilled in the art based upon a review of the foregoing description of preferred embodiments. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.