LUG LATCHING SYSTEM FOR COUPLING A LUBRICATOR TO A WELLHEAD

Description

FIELD OF THE INVENTION

The present invention generally relates to a high pressure, mechanically actuated lug latching system for coupling surface equipment such as a lubricator to a wellhead.

BACKGROUND

Oil well service or completion operations are conventionally performed with tools conveyed on wireline or coil tubing into the wellbore. A lubricator is used to contain long tools attached to the wireline or coil tubing. The lubricator is attached to a valve on top of the wellhead. Once the lubricator is securely attached, its internal pressure can be equalized with the wellhead and the tools can be pumped down hole. Typically, wireline tools such as fracking plugs and perforating guns are attached to the wireline and contained in the lubricator. One set of these tools are typically consumed for each fracking stage requiring them to be removed from the well and replaced with a new set numerous times per well. This means the lubricator must be removed and attached from the well head as many times as there are stages in a well. The lubricator is suspended from a crane during operation enabling it to be picked up once the connection to the wellhead is broken. It is then moved clear of the wellhead to drop tools out of and pull tools into the lubricator. The act of making and breaking a large diameter high pressure connection is cumbersome, dangerous and time consuming. Modern well sites typically have multiple wells on a single pad, so the lubricator is moved from well to well, making and breaking the connection each time.

Conventionally, the connection between the lubricator and the well head valve is made with well-known connectors such as a hammer union pipe fitting or a Bowen connection. These are threaded connections that require at least one person to be sent up to the connection on a man-basket to manually loosen or tighten the connection. The joint is typically about 15 feet above ground level. This time-consuming job creates fall hazards and pinch hazards.

More recently, hydraulic systems have been developed that utilize hydraulically actuated locking lugs to lock and release the joint between the lubricator and the wellhead. Such systems require specially trained operators as well as hydraulic lines being strung all over the well site creating tripping hazards and potential for spilled hydraulic oil. The systems are often complex and expensive making them prone to mechanical issues and high operating costs. The hydraulic latching mechanism can be put on the lubricator, but this leaves hoses dangling while moving from well to well and while changing tools. If the hydraulic latch mechanism is placed on the well head, multiple units are required for a standard multi-well pad which is typical in the modern oil field.

There is a need in the art for a system that attaches the lubricator to the wellhead quickly and securely, with a mechanism that does not require hoses or hydraulic pumps or fluids. Ideally, operation of the connection should be simple enough to avoid the need for special training for safe operation.

SUMMARY OF THE INVENTION

Embodiments of a mechanically actuated lug latching system disclosed herein enables quick secure attachment of a surface equipment to a wellhead by setting the connection together and then locking the system by indexing the system. The surface equipment may comprise a lubricator used in a wireline or a coil tubing operation. The connection can then be released by setting the lubricator back down at least once to index the latching system and picking back up to unlock and remove the lubricator. No hydraulic lines are needed and no personnel are required to manually make the connection.

In one aspect, disclosed is a latching system comprising:

• • (a) a stinger configured to attach to an upper end of a wellhead;
  • (b) a coupler assembly configured to attach to a lower end of a lubricator and having a latching mechanism for securely engaging the stinger, the latching mechanism moveable between a locked position and an unlocked position; and
  • (c) an indexing mechanism for indexing the latching mechanism from an unlocked position to a locked position, and from a locked position to an unlocked position, wherein the indexing mechanism is configured to translate vertical movement of the coupler assembly to index the latching mechanism.

In some embodiments, the indexing mechanism comprises a cam ring defining a cam slot and a cam follower sleeve disposed around the cam ring, and having at least one cam follower, wherein the cam follower is positioned within the cam slot and follows an indexing pattern when the cam ring is moved axially relative to the cam follower sleeve.

In some embodiments, the latching mechanism comprises moveable lugs which extend to engage the stinger and retract to disengage the stinger in response to movement of the indexing mechanism. The lugs may comprise elements which engage a shoulder, a ridge, a thread, or a detent formed on or by the stinger.

In some embodiments, the cam ring defines an internal profile having an inside diameter which varies along the axial length of the cam ring, the internal profile bearing on the latching mechanism, such that axial movement of the cam ring relative to the latching mechanism causes the lugs to extend or retract.

In some embodiments, the latching system can further comprise a centering cone positioned either on the stinger or the coupling assembly to aid in vertical alignment of the latching system.

In another aspect, disclosed is a latching coupler assembly for connecting to a stinger having a lock feature comprising:

• • (a) a lug housing having at least one latching component and configured to receive the stinger, the at least one latching component moveable between a locked state engaging the stinger lock feature and an unlocked state;
  • (b) a cylindrical cam ring disposed around the lug housing and moveable both axially and rotationally around the lug housing, the cam ring defining an exterior cam profile groove having at least one lock position, at least one unlock position, and an intermediate transition position, the cam ring further having an internal profile bearing on the at least one lug assembly to move each lug inward to its locked position;
  • (c) a cam follower sleeve affixed to the lug housing and disposed around the cam ring, the cam follower sleeve having at least one cam follower which engages the cam profile groove;
  • (d) wherein axial movement of the cam ring relative to the cam follower sleeve causes the cam follower to move within the cam profile groove between the lock position, the unlock position and the transition position, thereby moving the at least one latching component to its locked state or its unlocked state.

In some embodiments, the lock feature comprises a shoulder, a ridge, a thread, or a detent formed on or by the stinger.

In another aspect, disclosed is a method of latching and unlatching a surface equipment to a wellhead, comprising the steps of:

• • (a) lowering a coupler assembly attached to the surface equipment onto a stinger attached to the wellhead;
  • (b) indexing the coupler assembly from in an installation configuration to a first transition position by setting the coupler assembly down on the stinger;
  • (c) indexing the coupler to a locked configuration pulling up on the coupler assembly, which actuates a latching assembly to extend at least one lug radially inwards to securely engage the stinger to the coupler assembly; and
  • (d) indexing the coupler assembly to a second transition position by setting the coupler assembly down and unlocking by pulling up the coupler assembly, which actuates the latching assembly to release the stinger by retracting the at least one lug radially outwards.

In some embodiments, the latching system or method may comprise any one feature, element or step described or illustrated herein, or any combination of such features, elements or steps.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate some, but not the only or exclusive, examples of embodiments and/or features.

FIG. 1 shows one example of a lubricator assembly being positioned to connect to a wellhead using one embodiment of a latching system described herein. FIG. 1A shows a partial cutaway view of one embodiment of the latching system described herein. FIG. 1B shows a longitudinal cross-section of a stinger shown in FIG. 1B. FIG. 1C shows a longitudinal cross-section of a coupler assembly shown in FIG. 1A.

FIG. 2 shows a cross-section of the embodiment of FIG. 1A, in its locked state.

FIG. 3A shows the exterior of one embodiment of a cam ring. FIG. 3B shows a cross-section of one embodiment of a cam follower sleeve. FIG. 3C shows a cross-section of the cam ring of FIG. 3A. FIG. 3D shows an alternative embodiment of the cam ring, with a closed loop cam groove.

FIG. 4 shows a cross-section of the embodiment of FIG. 1A, in its unlocked state.

FIG. 5 shows a cross-section of the embodiment of FIG. 1A, in a transition/installation unlocked state.

FIG. 6 shows a pictorial view of one embodiment of a lug assembly.

FIG. 7 shows a cross-section of the lug assembly of FIG. 6.

FIG. 8A shows a cross-section of an alternative embodiment of the latching system, comprising an alternative lug system. FIG. 8B shows a partial cross-section of the latching mechanism. FIG. 8C shows the alternative lug of FIGS. 8A and 8B.

FIG. 9 shows the embodiment of FIG. 1A, with an entrance guide cone assembly.

DETAILED DESCRIPTION

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are exemplified. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout. It is to be understood that this invention is not limited to the particular methodology and protocols described, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.

Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

In this description, the directional prepositions of up, upwardly, down, downwardly, front, back, top, upper, bottom, lower, left, right and other such terms refer to the device as it is oriented and appears in the drawings and are used for convenience only; they are not intended to be limiting or to imply that the device has to be used or positioned in any particular orientation. Conventional components of the invention are elements that are well-known in the prior art and will not be discussed in detail for this disclosure. The terms “longitudinal” or “axial” refer to a direction parallel to the long axis of the system, which is shown vertically in FIG. 2, for example. The terms “radial” or “transverse” refers to a direction perpendicular to the axial direction.

Embodiments of a mechanically actuated lug latching system disclosed herein enables quick and secure attachment of a surface equipment to a wellhead by setting the connection together and then pulling up on the connection to lock the system. The surface equipment may comprise a lubricator (L) used in a wireline or a coil tubing operation, as may be seen in FIG. 1. The connection can then be released by setting the lubricator back down at least once to index the latching system and picking back up to unlock and remove the lubricator. Preferably, no hydraulic lines are needed and no personnel are required to go into a man basket to manually make the connection.

FIG. 1 shows a connection system which comprises a stinger 700 attached to a well head (WH) adapter and a mechanical coupler assembly 400 which is mounted below a lubricator (L) assembly. A conventional BOP and valve stack are part of the assembly as is well known in the art. The mechanical coupler assembly 400 may be connected to the lubricator stack and the stinger 700 connected to the wellhead in any suitable manner. As may be seen in FIG. 1A, for example, the coupler assembly 400 may comprise a coupler flange 110 threaded to the upper end of a lug housing 120. Alternatively, a collar or an integrated flange may be provided. The stinger 700 can be attached to the wellhead with an integrated flange (not shown) or a Bowen style flange 122 and Bowen nut 121 which clamps a stinger flange 123.

In alternative embodiments, the connection system may be configured such that the coupler assembly is attached to the wellhead and the stinger is carried on the surface equipment, such that stinger is inserted into the coupler assembly from the top.

In general terms, the connection is made and disconnected by axial movement of the coupler assembly 400 about the stinger 700. The coupler assembly 400 comprises an indexing mechanism to index the connection, as described herein. Axial movement indexes the coupler assembly between locked and unlocked states. The coupler assembly further comprises a latching assembly which physically engages the stinger to complete the connection. The stinger defines an outer profile comprising a stinger collar 118 which defines a locking shoulder 701, or an alternative physical feature which can mechanically lock the stinger to the coupler assembly 400, such as ridges or threads. The shoulder 701 is engaged by a moveable lug which is part of the latching assembly. The indexing assembly actuates the latching assembly but is otherwise independent of the latching assembly.

When connected, a fluid-tight seal between the stinger 700 and the coupler assembly 400 is provided by O-ring seals, placed in grooves 139 and 139a on the outer diameter of the stinger, or they could be placed in the inside diameter of the lug housing 120.

The coupler assembly 400 latching assembly comprises a lug housing 120 having a plurality of lug assemblies 500 installed. Each lug assembly 500 comprises a lug 124 which is moveable radially inward and outward. Each lug 124 fits within an opening formed in the lug housing 120, when in the unlocked position. When the connection system is in a locked position, shown in FIGS. 1A and 2, the lugs 124 are closer to the central axis (inward) of the lug housing, interfering with the downward facing locking shoulder 701 of the stinger collar 118, which prevents upward movement of the lug housing 120 relative to the stinger 700. Thus, the lugs 124 lock the lug housing 120 to the stinger 700.

The coupler assembly 400 indexing mechanism comprises a cylindrical cam ring 119 and a cam follower sleeve 113. The cam ring 119 is disposed within the cam follower sleeve 113 and around the lug housing 120. The cam ring 119 is free to rotate around the lug housing 120 and can also translate axially relative to the lug housing 120. Axial movement of the cam ring 119 relative to the lug housing 120 actuates the lug assemblies as the cam ring 119 defines an inner profile having varying inside diameters 901, 902, 903. The inner profile permits and constrains outward movement of the lugs 124. The outer surface of the cam ring 119 further defines a cam profile slot 137 which is part of the indexing assembly.

The cam follower sleeve 113 comprises at least one inwardly protruding cam follower 1002, which is a pin which engages and travels within the cam profile slot 137. The cam follower sleeve 113 is fixed axially relative to the lug housing 120, however, in some embodiments, the cam follower sleeve 113 is permitted to rotate about the long axis of the lug housing 120. Thus, axial and rotational movement of the cam ring 119 are guided by movement of the cam followers 1002 within the cam profile slot 137. The cam ring 119 can rotate and translate in either direction, but can be biased in one direction or the other by the shape of the cam profile groove 137. Axial movement of the cam ring 119 relative to the cam follower sleeve 113 causes the cam ring 119 to move axially and rotationally within the cam follower sleeve 113, due to the diagonal paths defined by the cam profile slot 137. As the cam follower sleeve 113 is fixed in position relative to the lug housing 120, this movement causes the cam ring 119 to move axially relative to the lug housing 120, and the inner profile thus moves to actuate the lugs 124 inward or to permit the lugs 124 to move outwards depending on inner profile's axial position relative to the lug assemblies 500.

The cam follower sleeve 113 is mounted to the lug housing 120 by means of a spring housing 114 which defines an outer circumferential groove 140. Pins 112 mounted inside the cam follower sleeve 113 are positioned within groove 140, thereby permitting rotation of the follower sleeve 113 but constraining axial movement relative to the lug housing 120. A spacer 111 and a shroud assembly 111a, 111b, 111c covers an upper portion of the spring housing 114 to protect the coupler assembly 400 from the elements.

The spring housing 114 also comprises and guides a biasing means to bias the cam sleeve 119 downwards. In one embodiment, the biasing means comprises at least one cam spring 115. The cam spring 115 can comprise a single cam spring having a diameter which encircles the lug housing 120 (shown in FIG. 8A), or may comprise a plurality of smaller coil springs 115, each of which is guided by a cam spring guide 116 which rises from the top of the lug housing 120. The cam springs 115 bias the cam ring 119 downwards relative to the lug housing 120 and cam follower sleeve 113, to ensure the cam ring 119 indexes properly and maintains position.

One embodiment of the cam ring 119 is shown in FIG. 3A and one embodiment of the cam follower sleeve 113 is shown in FIG. 3B. One skilled in the art will appreciate that longitudinal movement of a cam follower 1002 within the cam profile slot 137 will cause it to follow the circumferential pattern of the slot 137 around the circumference of the cam ring. The cam profile slot 137 has a pattern comprising a locked position, an unlocked position, and at least one transition position between locked and unlocked position. In alternative embodiments, the cam profile slot and the cam followers can be switched, such that the cam followers protrude outwards from a cam ring and engage the cam profile slot formed on an inner surface of a cam sleeve.

Openings 805 in selected locations in the slot 137 permits installation of the cam followers 1002 when the cam ring 119 is inserted into the cam follower sleeve 113, during assembly of the coupler assembly 400.

In one embodiment, the slot 137 comprises a pattern of positions 801, 802, 803 and 804, each of which corresponds to a specific state of the connection system as it is installed and operated. In one embodiment, there are at least two repeats of the pattern, corresponding to at least two cam followers 1002 attached to the cam follower sleeve 113. Preferably, there are between 4 to 8 repeats of the pattern, with a corresponding number of cam followers 1002.

In one embodiment, the cam profile slot 137 comprises a continuous “W” form with four distinct positions consisting of a locked position 801, an unlocked position 803, and two transition index positions 802, 804. The cam profile slot is a continuous slot formed around the circumference of the cam ring 119, without an entry or exit. In alternative embodiments, instead of the illustrated cam profile slot 137 that continues completely around the circumference of the cam ring, the cam profile slot 137 may comprise at least one closed loop, as may be seen in FIG. 3D. In another alternative embodiment, the cam profile can have three or more index locations instead of two, requiring the operator to set the lubricator down two or more times before the system is indexed to its unlocked position.

The indexing mechanism may comprise any variety of cam-like mechanisms could be used to position the inner profile at two different positions relative to the lug assemblies, to engage or disengage them from the stinger. In an alternative embodiment, the indexing mechanism can comprise groove and key profiles with tapered tops (not shown), analogous to a retracting ink pen mechanism with two positions.

The latching assembly comprises a radially moveable lug which securely engages the coupler assembly 400 to the stinger 700. Generally, a lug is a projection on an object by which it may be carried or fixed. One embodiment of a lug assembly 500 is shown in FIGS. 6 and 7. The lug assemblies 500 fit within a cavity formed in the lug housing 120, and each comprise a lug 124 mounted on a lug stem 505, secured by a set screw 606, and have an upper load bearing surface 506, lower load bearing surface 507, and a debris gutter 503 which continues downward 502. The lug stem 505 transmits force from the cam ring 119 into the lug 124 to force and hold it in place while that cam ring 119 is in the locked position. An internal retracting mechanism positioned within the lug stem 505 comprises a retractor 504 and a lug spring 604. The lug retractor 504 positions the lug assembly in the lug housing cavity, and transmits spring force which biases the lugs into a retracted position within the lug housing 120, when the cam ring 119 is in the unlocked position.

In some embodiments, inward facing reliefs 501 provide space for debris such as grease or sand to gather. The lug assembly 500 may further comprises a lug cam follower wheel 603 mounted on axle 601, and lug spring retainer 602.

The locked state of the system, shown in FIGS. 1 and 2, corresponds to cam follower position 801, where the cam ring 119 is positioned relatively lower in the assembly, such that locked profile 903 bears on the lug assemblies 500. The unlocked state of the system, shown in FIG. 4, corresponds to position 803, where the cam ring 119 is positioned higher in the assembly, such that unlocked profile 901 provides space for the lug assemblies 500 to retract. Thus, the system may be transitioned from one state to another by repeatedly raising and dropping the coupler assembly 400, which moves the cam ring 119 axially within the coupler assembly 400. The cam followers 1002 will then follow the cam profile slot 137 pattern and move from one cam profile slot position to the next.

The lugs 124 may be unlocked by lowering the lubricator which indexes the cam to the unlocked position 802. When the lubricator is lowered the bottom edge of the cam ring 119 will contact the upper surface of the Bowen nut 121. This presses the cam ring 119 up relative to the lug housing 120 and cam follower sleeve 113. The profile cam followers 1002 move into the index to unlocked position 802 which aligns the larger inside diameter 901 of the cam ring with the lug assembly 500 allowing the spring lug retractor 504 actuated by the lug spring 604 to retract the lug assembly 500 back into the lug housing 120. If the springs are not strong enough to retract the lug assembly 500 back into the housing due to debris or binding, the increased outer diameter on the lower portion of the stinger will push the lugs back into place using the weight of the lubricator. When the lubricator is then lifted, the profile cam followers will move into transition position 803 on the cam ring. The lug assembly will remain retracted enabling the coupler assembly 400 to be removed from the stinger 700.

To connect the coupler assembly 400 to the stinger 700, the lubricator with the coupler assembly 400 attached to the bottom is lowered onto the stinger 700, such as with a crane. In an installation position, the connector system is assembled such that the cam followers are in position 802, which is an intermediate position between the fully locked 801 and unlocked 803 positions. When the coupler assembly 400 is unweighted, the springs 115 and the weight of the cam ring 119 will then cause the cam followers 1002 to index to transition position 803 by urging the cam ring 119 downwards relative to the cam followers. The coupler assembly 400 can then be lowered onto the stinger. In this position, as shown in FIG. 5, the lugs 124 are free to pass over the sloped stinger collar 118 as the stinger 700 enters the coupler assembly 400.

In some embodiments, a guidance assembly 200 can be affixed to a lower portion of the coupler assembly 400, which aids the operator in centering the coupler assembly 400 over the stinger 700. In one embodiment, the guidance assembly comprises a cone 202, which in this embodiment is attached to the lower edge of the cam ring 119. The cone 202 is structurally reinforced with ribs 204. Preferably, the inside surface of the cone 202 and the outer rim 206 are lined or coated with a soft material, such as a polymer or a rubber, to prevent stinger seal damage caused by misaligned impact with the stinger 700. The large diameter cone 202 enables easier alignment of the system with the crane.

Once aligned, the coupler assembly 400 is lowered until the lower edge of the cam ring 119 contacts the upper surface of the Bowen nut 121 as shown in FIG. 4. As soon as the downward force exceeds the biasing force of springs 115, the cam ring 119 is pushed up into the coupler assembly. As a result, the cam followers 1002 will index from cam position 803 to cam position 804. Lifting the lubricator with coupler assembly 400 will then cause the profile cam followers 1002 to move into the locked cam position 801.

When the profile cam followers 1002 are positioned in the locked cam position 801 the cam ring 119 is positioned lower relative to the lug housing 120. The cam ring 119 inner profile comprises locking portion 903 with a reduced inside diameter, and an unlocking portion 901 with a greater diameter. When locking portion 903 of the cam ring 119 aligns with the lug assembly 500, the lugs 124 are pressed inwards. The smaller inside diameter 903 of the cam ring 119 pushes on the lug cam follower wheel 603 and forces the lug assembly 500 inwards, towards the central axis of the coupler assembly 400. In the locked position, the upper surface of the lugs 124 abut the stinger collar lug locking shoulder 701. The lugs 124 resist the shear force generated by pressurization of the lubricator when pressure is equalized with the wellhead and thus ensure that the coupling assembly 400 does not separate from the stinger 700 and maintains a fluid-tight connection.

In one embodiment, a seal test port 138 defined by the lug housing 120 allows seal integrity to be tested. A fitting may be connected to the seal test port 138 and pressure applied, thereby confirming that the seals placed in the main bore seal grooves 139 and 139a will retain pressure.

In the embodiment shown in FIGS. 1A-7, a single row of four lugs provides the latching engagement between the stinger 700 and the coupler assembly 400. The lugs may be designed with sufficient contact area for the desired pressure rating. If a greater pressure rating is desired or necessary, multiple rows of lugs may be provided to increase the effective strength of the latching mechanism. In some embodiments, the lugs may comprise a different engagement surface than a flat surface which engages a shoulder. For example, as shown in FIGS. 8A-8C, peanut-shaped lugs 1203, arrayed in multiple rows, engage a plurality of detents having a complementary shape to the lugs 1203.

In alternative embodiments, one example of which is shown in FIGS. 8A-8C, the indexing mechanism comprises a cam ring 1202 defining a cam slot 1208 and a cam follower sleeve 1201, which function as described above. A mounting flange 1209 and Bowen flange 1210 with a Bowen nut 1211 connect to the surface equipment and the wellhead respectively. A sliding sleeve 1205 abuts a travel stop shoulder 1215 formed on the stinger 1214 when the assembly is in the locked position, as may be seen in FIG. 8A. A single large cam spring 1206 is positioned around the exterior of the lug housing 1213. Spacer 1212 mounts the cam follower sleeve 1201 to the lug housing 1220 with pins 1207A. FIG. 8B shows the same embodiment with the cam ring 1202 removed to show the lug housing 1213. The latching assembly comprises a plurality of elongate, oval or peanut-shaped lugs 1203, arrayed in a plurality of horizontal row, each of which engages a complementarily shaped detent in the sliding sleeve 1205. Lug biasing springs are not necessary as radial movement of the lugs is actuated by axial movement of the curved surfaces of the cam ring inner profile and the curved shape of the detents.

In other alternative embodiments, the lugs could also take the form of threaded or multi plane engagement surfaces to help distribute load for higher pressure applications.

In some embodiments, each cam position has a corresponding indicator ring 133, 134, 135 on the outside diameter of the cam ring 119 that will be positioned and visible just under the lower edge of the cam follower sleeve 113. These rings may be visually identifiable, ie. with colour. This enables the operator to visually verify that the profile cam followers have reached the intended position before changing crane direction. When the cam is in the locked position the lower edge will be just above the locked position indicator groove 133. Preferably, this groove can be painted a highly visible colour, ie. green, to indicate the system is ready for pressure when green is visible. The unlocked position indicator groove 134 and the index position indicator groove 135 will be just below the edge when the system is in its respective position. Preferably, these grooves could be painted red and yellow respectively as signals to the operator.

When placed in the locked position, as shown in cross section view in FIG. 2, screws 131 can be threaded into cam lock out screw holes 1003 to engage the cam lock out groove 132 defined by cam ring 119, which secures the system in its locked state. This can prevent the system from unlocking if the lift crane has to be removed.

Interpretation

The forgoing description supplies specific details in order to provide a thorough understanding. Nevertheless, the skilled artisan would understand that the apparatuses, systems, and associated methods of using the apparatuses and systems can be implemented and used without employing these specific details. Indeed, the apparatuses, systems, and associated methods can be placed into practice by modifying the illustrated apparatus and associated methods and can be used in conjunction with any other apparatus and techniques conventionally used in the industry.

The corresponding structures, materials, acts, and equivalents of all means or steps plus function elements in the claims appended to this specification are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed.

References in the specification to “one embodiment”, “an embodiment”, etc., indicate that the embodiment described may include a particular aspect, feature, structure, or characteristic, but not every embodiment necessarily includes that aspect, feature, structure, or characteristic. Moreover, such phrases may, but do not necessarily, refer to the same embodiment referred to in other portions of the specification. Further, when a particular aspect, feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one skilled in the art to affect or connect such module, aspect, feature, structure, or characteristic with other embodiments, whether or not explicitly described. In other words, any module, element or feature may be combined with any other element or feature in different embodiments, unless there is an obvious or inherent incompatibility, or it is specifically excluded.

It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for the use of exclusive terminology, such as “solely,” “only,” and the like, in connection with the recitation of claim elements or use of a “negative” limitation. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.

The singular forms “a,” “an,” and “the” include the plural reference unless the context clearly dictates otherwise. The term “and/or” means any one of the items, any combination of the items, or all of the items with which this term is associated. The phrase “one or more” is readily understood by one of skill in the art, particularly when read in context of its usage.

As will also be understood by one skilled in the art, all language such as “up to”, “at least”, “greater than”, “less than”, “more than”, “or more”, and the like, include the number recited and such terms refer to ranges that can be subsequently broken down into sub-ranges as discussed above. In the same manner, all ratios recited herein also include all sub-ratios falling within the broader ratio.