The present disclosure relates in general to devices and mechanisms for releasably latching two coaxially-positioned and mating rotary components such that relative axial displacement of the rotary components is prevented when in the latched position, but axial displacement is allowed when the rotary components are in the unlatched position.
Power tongs have for many years been used to “make up” (i.e., assemble) threaded connections between sections (or “joints”) of tubing, and to “break out” (i.e., disassemble) threaded connections when running tubing strings into or out of petroleum wells, in coordination with the hoisting system of a drilling rig. Tubing strings typically comprise a number of tubing sections having externally-threaded ends, joined end to end by means of internally-threaded cylindrical couplers mounted at one end of each tubing section, forming what is commonly called the “box” end, while the other externally-threaded end of the tubing section is call the “pin” end. Such tubular strings can be relatively efficiently assembled or disassembled using power tongs to screw additional tubing sections into a tubing string during make-up operations, or to unscrew tubing sections from a tubing string being pulled from a wellbore (i.e., break-out operations).
However, power tongs do not simultaneously support other beneficial functions such as rotating, pushing, or fluid filling, after a pipe segment is added to or removed from the string, and while the string is being lowered or raised in the wellbore. Running tubulars with tongs, whether powered or manual, also typically requires the deployment of personnel in comparatively high hazard locations such as on the rig floor and on so-called “stabbing boards” above the rig floor.
The advent of drilling rigs equipped with top drives has enabled another method of running tubing strings, and casing strings in particular, using tools commonly known as casing running tools or CRTs. These tools are adapted to be carried by the top drive quill, and to grip the upper end of a tubing section and to seal between the bore of the tubing section and the bore of the top drive quill. In coordination with the top drive, CRTs support hoisting, rotating, pushing, and filling of a casing string with drilling fluid while running casing into a wellbore.
Ideally, these tools also support the make-up and break-out operations, traditionally performed using power tongs, thereby eliminating the need for power tongs entirely, with attendant benefits in terms of reduced system complexity and increased safety. As a practical matter, however, obtaining these benefits without negatively impacting running rate or consistency requires the time taken to make up connections using CRTs to be at least comparable to the running rate and consistency achievable using power tongs. In addition, it is a practical necessity that making up tubing strings using CRTs does increase the risk of damage to the connection threads, or to seals in so-called “premium connections” where these are present.
U.S. Pat. No. 7,909,120 (Slack) [the contents of which are incorporated herein in their entirety, in jurisdictions where so permitted] teaches a prior art CRT in the form of a gripping tool that includes a body assembly comprising:
For purposes of this patent document, a CRT configured for gripping an internal surface of a tubular workpiece will be referred to as a CRTi, and a CRT configured for gripping an external surface of a tubular workpiece will be referred to as a CRTe.
CRTs as taught by U.S. Pat. No. 7,909,120 utilize a mechanically-actuated gripping assembly that generates its gripping force in response to axial load with corresponding axial stroke, either together with or independently from externally-applied axial load and externally-applied torque load applied by either right-hand or left-hand rotation. These loads, when applied, are carried across the tool from the load adaptor of the body assembly to the grip surface of the gripping assembly, in tractional engagement with the workpiece.
Additionally, such CRTs or gripping tools may be provided with a latch mechanism acting between the body assembly and the gripping assembly, in the form of a rotary J-slot latch having a hook-and-receiver arrangement acting between first and second latch components, where the first latch component is carried by the body assembly and the second latch component is carried by the grip assembly (for example, see FIGS. 1 and 14 in U.S. Pat. No. 7,909,120, showing the latch in externally-gripping and internally-gripping full-tool assemblies respectively, and also FIGS. 4-7 in U.S. Pat. No. 7,909,120, describing how mating latch teeth 108 and 110 act as a hook and receiver with respect to each other.)
When in a first (or latched) position, with the hook in the receiver, this latch prevents relative axial movement between the body assembly and the gripping assembly so as to retain the grip mechanism in a first (or retracted) position. However, relative rotation between the body assembly and the gripping assembly (which rotation is typically resisted by some amount of torque, which will be referred to herein as the “latch actuation torque”) will move the mating hook and receiver components to a second (or unlatched) position, thereby allowing relative axial movement between the body assembly and the gripping assembly, with associated movement of the grip surface into the second (or engaged) position. Accordingly, when in the latched position, this latch mechanism will support operational steps that require the gripping assembly to be held in its retracted position, to enable positioning of the tool relative to the workpiece preparatory to engaging the grip surface, and conversely retaining the grip surface in its retracted position enabling separation of the CRT from the workpiece.
Operationally, achieving this relative movement where the CRT is attached to the top drive quill requires the development of sufficient reaction torque, through tractional engagement when the “land surface” of the CRT is brought into contact with the upper end of a tubular workpiece and axial “set-down” force is applied, to resist the latch actuation torque arising from the rotation applied to move the latch into the unlatched position (typically arranged as right-hand rotation) and to cause axial movement if required (i.e., to move the hook up the “slot” of a J-slot). Any operational step moving the latch from the latched position to the unlatched position is said to “trigger” the tool, thus allowing the tool to be “set”.
To re-latch, this same requirement for sufficient tractional resistance between the tool's land surface and the workpiece must be met, with the applied torque direction reversed (i.e., typically left-hand rotation) to “un-set” the tool. For mechanically-set CRT tools such as in U.S. Pat. No. 7,909,120, the tractional resistance required to re-latch is less than that required to unlatch.
U.S. Pat. No. 9,869,143 (Slack) [the contents of which are incorporated herein in their entirety, in jurisdictions where so permitted] discusses how it may be difficult in some applications to achieve sufficient tractional resistance between the land surface of a CRT and a workpiece, such as in cases where both the CRT land surface and the contact face of the workpiece are smooth steel, particularly when rotating to release the latch in such tools. U.S. Pat. No. 9,869,143 teaches means for increasing the effective friction coefficient acting between the workpiece and tool under application of compressive load (i.e., the ratio of tractional resistance to applied load). While these teachings disclose effective means for managing this operational variable and thus reducing operational uncertainty, operation of the tool still requires the steps of first setting down a somewhat controlled amount of axial load and then applying rotation with the top drive to move the latch into its unlatched position. Therefore, when the CRT is used to for make-up operations, the time, load, and rotation control to carry out these steps on certain rigs may result in slower cycle times than achievable using power tongs for make-up.
Tubing sections in a tubing string are typically oriented “pin down, box up”. Accordingly, during make-up operations, the upper end of the uppermost section in the string, as supported by rig floor slips or a “spider”, presents as “box up” in the so-called “stump” into which the pin end of the next tubing section (i.e., workpiece) is stabbed. When using a CRT for make-up, it may be difficult to control the amount of top drive “set-down” load on the stabbed pin and similarly the amount of rotation applied with set-down load present, introducing the possibility of the undesirable situation where the pin end of the workpiece is rotated in the box in the stump before the pin-end and box-end threads are properly engaged, with the attendant risk of galling damage to the threads. While these risks can be ameliorated by careful control of the top drive by the driller, they contribute to both additional uncertainty and increased cycle time.
Accordingly, there is a need for methods and means for reducing the risk of thread damage when using CRTs for make-up, and for providing greater assurance of cycle times comparable to or less than cycle times achievable using power tongs for make-up and other aspects of casing running operations.
In general terms, the present disclosure teaches non-limiting embodiments of a rotary latch mechanism (alternatively referred to as a trigger mechanism) comprising upper and lower latch assemblies, plus a latch release mechanism comprising an upper rotary latch component carried on and rotationally coupled to the upper latch assembly, and a lower rotary latch component carried on and rotationally coupled to the lower latch assembly. The upper and lower rotary components are adapted to move from a first (or axially-latched) position to a second (or axially-unlatched) position in response to rotation of the lower rotary component relative to the upper rotary component in a first (or unlatching) direction. Such rotation induces the development of an associated latch actuation torque.
The latch release mechanism has a movable land element (alternatively referred to as a “cushion bumper”) which carries a downward-facing land surface that acts in response to relative axial displacement to urge relative rotation between the upper and lower rotary latch components, so as to exert the latch actuation torque required to move the latch components from the latched position to the unlatched position. Where needed for latch configurations requiring both relative axial compression movement and rotation (such as commonly required for a J-slot latch), the mechanism may be configured such that the axial movement of the movable land element will cause the relative axial movement required to release the latch in combination with the required rotation. Accordingly, exemplary embodiments in accordance with the present teachings are directed to means for inducing the rotation and latch actuation torque required to move the component forming a rotary latch from the latched position to the unlatched position using externally-controlled axial movement of a movable land element carried by the latch release mechanism, without requiring externally-induced rotation sufficient to move the mechanism from the latched position to the unlatched position.
Latch release mechanisms as disclosed herein eliminate the need for externally-applied rotation after applying set-down force when using a tool such as a mechanical CRT tool that employs a J-latch type mechanism to move from a first (latched) to a second (unlatched) position, by transforming relative axial movement between the tubular workpiece and a component of the tool so as to produce the relative rotation needed to release the latch. This enables a mechanical CRT equipped with such a latch release mechanism (or trigger mechanism) to produce comparable or shorter cycle times with reduced risk of connection thread damage while running casing, as compared to using power tongs for such operations.
In one aspect, the present disclosure teaches embodiments of a rotary latch release mechanism comprising:
The rotary latch release mechanism may include a first axially-oriented biasing means acting between the upper and lower latch assemblies so as to bias the latch release mechanism toward the latched position, and a second axially-oriented biasing means acting between the movable bumper element and the trigger element so as to bias the bumper element axially downward relative to the trigger element.
The upper latch assembly may define a downward-facing upper ramp surface that is matingly engageable with an upward-facing lower ramp surface defined by the lower latch assembly, such that the application of an upward force to the land surface of the bumper element will bring the upper and lower ramp surfaces into sliding engagement so as to constrain the relative axial approach of the upper and lower latch assemblies while allowing relative rotation between the upper and lower latch assemblies.
Several exemplary embodiments of latch release mechanisms in accordance with the present disclosure are described below, in the context of use with a CRT tool utilizing a J-latch to retain the grip surface of the CRT in its retracted position, and providing means for triggering the J-latch by application of set-down load without requiring the application of external rotation and latch actuation torque through the load adaptor.
Embodiment #1 relies on tractional resistance to react latch actuation torque. In this embodiment, the latch release mechanism is carried by the lower latch assembly (comprising the grip assembly of a CRT), and has a movable land element (or cushion bumper) with a generally downward-facing land surface adapted for tractional engagement with the upper end of a tubular workpiece. Upward axial compressive movement of the movable land element relative to the lower rotary latch component, in response to contact with a tubular workpiece, causes the latch release mechanism to rotate the lower rotary latch component relative to the upper rotary latch component in the unlatching direction.
The latch release mechanism is further provided with biasing means (such as but not limited to a spring), for biasing the land surface to resist axial compressive displacement relative to the lower rotary latch component, correspondingly producing tractional resistance to rotary sliding between the land surface and the tubular workpiece. Thus arranged, with the upper and lower rotary latch components initially in the axially-latched position, and with the upper latch assembly (comprising the body assembly of a CRT) supported through the load adaptor to resist rotation relative to the tubular workpiece, axial compressive movement transmitted through the load adaptor to the upper rotary latch component relative to the tubular workpiece tends to urge rotation, as well as axial compressive stroke, if required, of the lower rotary latch component relative to the upper rotary latch component, and where tractional resistance between the land surface and the tubular workpiece is sufficient to exceed the latch actuation torque, the axial compressive movement causes rotation relative to the upper rotary latch component to move the lower rotary latch component to the unlatched position.
Embodiment #2, like Embodiment #1, relies on tractional resistance to react latch actuation torque. In this embodiment, the upper latch assembly has a load adapter slidingly coupled to a main body to carry axial load while still allowing axial stroke. The upper rotary latch component is axially carried by the main body, but is rotationally coupled to the load adaptor. The lower latch assembly is carried by and is rotationally coupled to the main body, while allowing axial sliding, over at least some range of motion, when in the unlatched position. The lower latch assembly is further adapted to carry a land surface for contact with a tubular workpiece to support set-down loads and to provide tractional resistance to rotation.
The latch release mechanism is carried by a selected one of the load adaptor and the main body, and has a generally axially-facing movable clutch surface adapted for tractional engagement with an opposing reaction clutch surface on the other of the load adaptor and the main body. Axial compressive movement of the movable clutch surface relative to the reaction clutch surface, as urged by set-down force applied to the load adaptor, causes the latch release mechanism to urge rotation between the load adaptor and the main body in the unlatching direction. The latch release mechanism is further provided with biasing means (such as but not limited to a spring), for biasing the movable clutch surface to resist axial compressive displacement relative to the component on which it is carried (i.e., either the load adaptor or the main body), correspondingly producing tractional resistance to rotary sliding between the contacting movable clutch surface and the reaction clutch surface (or clutch interface).
Thus arranged, with the upper and lower rotary latch components initially in the axially-latched position, and with the load adaptor supported to generally allow free rotation relative to the main body and hence the tubular workpiece, axial compressive movement within the axial stroke allowance of the load adaptor relative to the main body tends to urge rotation, and axial compressive stroke if required, of the upper rotary latch component relative to the lower rotary latch component. Where the tractional resistance of the clutch interface is sufficient to exceed the latch actuation torque (and perhaps some external resistance torque of the generally freely-rotating load adaptor), the axial compressive movement induces rotation of the upper rotary latch component relative to the lower rotary latch component to move to the unlatched position.
Where free rotation of the load adaptor is inhibited, the rotation urged by set-down load tends to urge sliding at the clutch interface and at the land-to-workpiece interface. The corresponding torque induced at these two interfaces, upon application of sufficient set-down load, will thus tend to induce sliding on one interface or the other. If sliding occurs on the land-to-workpiece interface, the rotation necessary to release the latch will occur. However, if sliding occurs at the clutch interface, then relative rotation of the latch components will not occur, rendering the latch release mechanism ineffective for its intended purpose in these particular circumstances. It may therefore be advantageous to provide means for increasing the torsional resistance of the clutch interface to increase the effective tractional resistance under application of axial load, such as by providing these mating surfaces as conically-configured surfaces to increase the normal force driving rotational tractional resistance, for a given axial load. Such modifications may be provided in the absence of or in combination with contouring or other surface treatments for increasing frictional resistance.
However, in all cases where it is desired to allow for re-latching, the tractional resistance to rotation occurring at the clutch interface will tend to impede the relative rotation of upper and lower rotary latch components if set-down load is required to effect re-latching. For certain applications it may be possible to reliably control the tractional response of these two interfaces by providing a selected combination of bias spring force, contact surface geometry, and surface treatment of the clutch and land-to-workpiece surfaces, in coordination with load control sufficient to reliably prevent clutch interface slippage in support of latch release rotation for a first compressive load, while simultaneously allowing clutch interface slippage without resultant land-to-workpiece slippage to support re-latching, for a second selected compressive load in combination with applied rotation.
As described above, Embodiments #1 and #2 rely on the presence of sufficient tractional engagement between contacting components for reliable unlatching with set-down movement. In Embodiment #1, the only limiting tractional resistance is between the tubular workpiece and the cushion bumper, with the additional constraint that the latch actuation torque is further resisted by external support carrying the upper latch assembly. To state this otherwise, relative rotation between the upper rotary latch component and the tubular workpiece must be largely prevented (at least in the unlatching direction) to support grip engagement without externally-applied rotation.
In Embodiment #2, sufficient tractional resistance of the clutch interface is required, typically with the added constraint of free rotation of the load adaptor of the upper latch assembly. For applications where these boundary conditions can be readily and reliably met, Embodiments #1 and #2 can provide the benefits of faster cycle times and reduced risk of connection thread damage, plus the benefit of comparative mechanical simplicity. However, for applications where these boundary conditions cannot be readily achieved, means can be provided for releasing a J-latch independent of available tractional resistance or control of top drive rotation, as in alternative embodiments described below.
Embodiment #3 is configured to force relative rotation of the upper and lower rotary latch components through the latch release mechanism. In this embodiment:
The movable land element and the trigger element are coupled to each other and to the lower latch assembly such that upon upward axial compressive movement or stroke of the movable land element relative to the lower latch assembly from a first (or land) position to a second (or fully-stroked) position, as urged by contact with a tubular workpiece, will urge rotation and downward axial movement of the trigger dog teeth. Initially, the rotation of the trigger dog teeth is prevented by interaction with the reaction dog pockets which causes rotation of the lower rotary latch component relative to the upper rotary latch component to their unlatched position, and when the movable land element is fully stroked, the trigger dog teeth are fully retracted and disengaged from the reaction dog pockets. The retraction of the trigger dog teeth from the reaction dog pockets supports re-latching under application of external rotation in the re-latching direction. This embodiment preferably includes biasing means tending to resist both the axial compression of the movable land element and the retraction of the trigger element, so that the land and trigger elements return to their initial positions upon unloading and withdrawal from the tubular workpiece.
Embodiment #4, like Embodiment #3, is configured to force relative rotation of the upper and lower rotary latch components through the latch release mechanism. In this embodiment:
The latch release mechanism is provided to act between the sliding load adaptor and main body, and, similar to Embodiment #3, comprises three main elements:
In the following discussion, it will be assumed that the reaction dog pockets are upward-facing and are carried by a main body, and that the trigger element, having downward-facing trigger dog teeth, and the intermediate trigger element, having a downward-facing standoff surface, are carried by the load adaptor. When the tool is in the latched position, the trigger dog teeth and the trigger reaction dog pockets are configured for aligned engagement upon downward axial sliding movement of the load adaptor through its axial stroke, as urged by contact with a tubular workpiece.
An upward-facing reaction surface is also provided with the reaction dog pockets, and therefore is rigidly carried by the main body and arranged to contact the downward-facing standoff surface at an axial stroke position lower than required for engagement of the trigger dog teeth with the reaction dog pockets. The intermediate trigger element and the trigger element are coupled to each other and to the load adaptor assembly such that downward axial compressive movement or stroke of the standoff surface relative to the load adaptor from a first (land) position to a second (fully-stroked) position, as urged by contact with a tubular workpiece, will urge both rotation and upward axial movement of the trigger dog teeth.
Initially, the rotation of the trigger dog teeth is prevented by interaction with the reaction dog pockets which causes rotation of the lower rotary latch component relative to the upper rotary latch component to their unlatched position, and when the intermediate trigger element is fully stroked, the trigger dog teeth will be fully retracted and disengaged from the reaction dog pockets, and this retraction of the trigger dog teeth will support re-latching under application of external rotation in the re-latching direction. This embodiment preferably includes biasing means tending to resist both axial compression of the intermediate trigger element and retraction of the trigger element such that upon unloading and withdrawal from the tubular workpiece, the intermediate trigger and trigger elements return to their initial positions.
To further support reverse rotation under set-down load as needed to effect re-latching, the intermediate trigger may be provided as an intermediate trigger assembly comprising an intermediate trigger extension, having a downward-facing standoff surface, threaded to the intermediate trigger but rotationally keyed to the main body such that rotation in the direction of unlatching tends to move the standoff surface lower, causing compressive engagement of the standoff surface and the reaction surface at axially-higher positions, which prevents the premature engagement of the trigger dog teeth with the reaction dog pockets until the rotational position for re-latching has been reached.
Embodiments will now be described with reference to the accompanying Figures, in which numerical references denote like parts, and in which:
The upper end of body assembly 110 is provided with a load adaptor 112 (illustrated by way of non-limiting example as a conventional tapered-thread connection) for structural connection to a top drive quill (not shown) of a drilling rig (not shown). Grip assembly 120 includes a land surface 122 carried by a fixed bumper 121 rigidly attached to cage 500 of grip assembly 120. As described in US 2011/0100621 but not shown herein, body assembly 110 carries an upper rotary latch component, and grip assembly 120 carries a lower rotary latch component, which is linked to cage 500 so as to be generally fixed against rotation and axial movement relative to cage 500 when in the latched position, but configured for rotary movement to an unlatched position in response to typically right-hand rotation of body assembly 110 relative to grip assembly 120, with the latch actuation torque corresponding to this rotary movement being reacted by tractional engagement of land surface 122 with tubular workpiece 101.
Cage extension 222, trigger element 210, and movable bumper 218 are generally configured as a coaxially-nested group of closely-fitting cylindrical components, where relative rotary and translational movements between these components are constrained to keep them coaxially aligned, but also linked by cam pairs in the manner of cam followers and cam surfaces as described later herein.
Cage extension 222 carries a movable bumper 218 having a movable land surface 220 and a trigger element 210. Movable bumper 218 is linked to trigger element 210 by a bumper-trigger cam follower 314 rigidly fixed to movable bumper 218 and movable within an axially-oriented bumper-trigger cam slot 315 formed in trigger element 210, such that movable bumper 218 is axially-movable relative to trigger element 210. A bumper-cage cam follower 318, rigidly fixed to cage extension 222, is constrained to move within a bumper-cage cam slot 319 formed in movable bumper 218 (with bumper-cage cam slot 319 having an upper end 320 and a lower end 321); and a trigger-cage cam follower 322, rigidly fixed to cage extension 222, is constrained to move within a trigger-cage cam pocket 324 provided in trigger element 210.
Notwithstanding the particular and exemplary arrangement of the components of the latch release mechanism 201 as described above and illustrated in
In the illustrated embodiment, bumper-trigger cam slot 315 is provided as an axially-oriented slot, closely fitting with the diameter of the associated bumper-trigger cam follower 314, and thus having a single degree of freedom to permit only relative axial sliding movement between trigger element 210 and movable bumper 218 but not relative rotation, with a trigger bias spring 326 being provided to act between trigger element 210 and movable bumper 218, in the direction of axial sliding, to bias movable bumper 218 downward relative to trigger element 210. Bumper-cage cam slot 319 is sloped at a selected angle relative to the vertical (shown by way of non-limiting example in
During typical operations, the operative status of latch release mechanism 201 may be characterized with reference to the position of trigger-cage cam follower 322 within trigger-cage pocket 324, as follows:
When latch release mechanism 201 is in the latched position (as shown in
It will be apparent that upper rotary latch receiver 302 and lower rotary latch hook 312, configured as a J-slot requiring axial displacement, already provides some protection against accidental rotation. However, for the type of J-latch typically employed in CRTs where axial displacement is not required and unlatching with only torque is allowed, the trigger dog tooth lock flank 214 and mating reaction pocket lock flank 208 provide the additional benefit of protection against accidental rotation.
In actual operation of the rotary latch release mechanism, the contact force reacted by tubular workpiece 101 against movable land surface 220 tends to build as CRT 130 is lowered. However, as a matter of convenience for purposes of illustration in
Referring now to
While such upward movement causing axial separation of lower rotary latch hook 312 from upper rotary latch receiver 302 is not a required movement for the type of J-latch typically employed for all CRTs, as will be known to persons skilled in the art, mating latch hook 312 and latch receiver 302 can be alternatively configured to disengage in response to applied torque only.
Independent of whether the applied load is first sufficient to overcome the force of the internal bias spring, when sufficient force is applied by workpiece 101 to overcome the force of trigger bias spring 326, movable bumper 218 will move upward, causing bumper-cage cam follower 318 to move downward within sloped bumper-cage cam slot 319, as shown in
As may be seen with reference to
This rotation supports movement of lower rotary latch hook 312 into engagement with upper rotary latch receiver 302 (i.e., the latched position), with corresponding actuation torque being resisted by tractional engagement of movable land surface 220 with tubular workpiece 101. In general, though, the portion of the set-down load carried by contact between internal upper cam ramp surface 303 and internal lower cam ramp surface 304, as a function of the associated cam ramp angle, tends to require less tractional engagement for this re-latching movement than required for unlatching in tools having different types of latch release mechanisms.
Referring now to
In the embodiment illustrated in
As illustrated in
A drive cam body-housing seal 403, a drive cam body-mandrel seal 404, a drive housing-driven housing seal 421, a drive cam body-cage seal 472, and a cage mandrel seal 501 define an annular piston area and a gas spring chamber 422. When pressurized with a gas, gas spring chamber 422 forms an internal gas spring that tends to urge the separation of upper latch assembly 133 and lower latch assembly 134, thereby tending to urge separation of body assembly 110 and grip assembly 120 to move latch release mechanism 131 between a first (unlatched) position and a second (latched) position. Such separation is resisted by matingly-engageable drive cam latch hooks 401 and latch cam latch hooks 491, which can be disengaged by the application of sufficient right-hand torque (i.e., latch actuation torque) and corresponding right-hand rotation of body assembly 110 relative to grip assembly 120. Tri-cam latching linkage 132 is considered to be in the latched position when drive cam latch hooks 401 and latch cam latch hooks 491 are engaged, and in the unlatched position when drive cam latch hooks 401 and latch cam latch hooks 491 are disengaged.
The following section details a mechanism that can be employed to use only axial compression and corresponding axial displacement to generate the right-hand torque and rotation required to unlatch the tri-cam latching linkage 132, having reference to
As illustrated in
In operation, CRTi 130 with latch release mechanism 131 would first be inserted or “stabbed” into tubular workpiece 101 and lowered until movable land surface 451 contacts tubular workpiece 101, and the contact force resulting from tool weight and set-down load applied by the top drive (not shown) increases above the “trigger set-down load”, at which point latch release mechanism 131 has applied the required latch actuation torque and the displacement required to disengage drive cam latch hooks 401 and latch cam latch hooks 491. The gas spring will cause axial displacement of body assembly 110 relative to grip assembly 120, transitioning the CRTi tool 130 with latch release mechanism 131 from the retracted position to the engaged position. This operational sequence differs from prior art CRTi 100 in two ways:
As best understood with reference to
It will be apparent to persons skilled in the art that the cam follower can be fixed to either of the two components to be paired, with the cam profile defined in the other of the two paired components, and that the design choice in this regard will typically be based on practical considerations such as efficient assembly, disassembly and maintenance. Similarly, the choice of cam follower/cam surface as the means for providing the desired movement constraint is not intended to be in any way limiting, where persons skilled in the art will understand generally equivalent linkages can be provided in other forms.
In the embodiment shown in
During typical operations, the operative status of latch release mechanism 131 may be characterized with reference to the position of trigger cam follower 448 within trigger-cage pocket 424, as follows:
With the latch release mechanism in the latched position as in
Referring now to
Further upward movement of movable bumper 450 continues to urge rotation of cage extension 460 and, therefore, movement of trigger cam follower 448 to the withdrawn position within cage cam pocket 464, thereby moving trigger element 440 down and correspondingly withdrawing trigger dog teeth 441 from engagement with trigger reaction dog pockets 411 as shown in
With trigger element 440 withdrawn from trigger reaction ring 410 as shown in
Referring now to
It will be readily appreciated by those skilled in the art that various alternative embodiments may be devised without departing from the scope of the present teachings, including modifications that may use equivalent structures or materials subsequently conceived or developed. It is to be especially understood that it is not intended for apparatus in accordance with the present disclosure to be limited to any described or illustrated embodiment, and that the substitution of a variant of a claimed element or feature, without any substantial resultant change in the working of the apparatus and methods, will not constitute a departure from the scope of the disclosure.
In this patent document, any form of the word “comprise” is to be understood in its non-limiting sense to mean that any item following such word is included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one such element. Any use of any form of the terms “connect”, “engage”, “couple”, “latch”, “attach”, or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the subject elements, and may also include indirect interaction between the elements such as through secondary or intermediary structure.
Relational and conformational terms such as (but not limited to) “vertical”, “horizontal”, “coaxial”, “cylindrical”, “trapezoidal”, “upward-facing”, and “downward-facing” are not intended to denote or require absolute mathematical or geometrical precision. Accordingly, such terms are to be understood as denoting or requiring substantial precision only (e.g., “substantially “vertical” or “generally trapezoidal”) unless the context clearly requires otherwise.
Wherever used in this document, the terms “typical” and “typically” are to be understood and interpreted in the sense of being representative of common usage or practice, and are not to be understood or interpreted as implying essentiality or invariability.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2018/000144 | 7/20/2018 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
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WO2019/014747 | 1/24/2019 | WO | A |
Number | Name | Date | Kind |
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2028966 | Burns | Jan 1936 | A |
7909120 | Slack | Mar 2011 | B2 |
9869143 | Slack | Jan 2018 | B2 |
20110100621 | Slack | May 2011 | A1 |
20120013133 | Rios, III | Jan 2012 | A1 |
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20130146298 | Ellison | Jun 2013 | A1 |
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20170183923 | Bansal et al. | Jun 2017 | A1 |
Number | Date | Country |
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106812480 | Jun 2017 | CN |
Entry |
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International Search Report re PCT/2018/000144, issued by the ISA/CA dated Sep. 28, 2019. |
Written Opinion of the International Searching Authority re PCT/2018/000144, issued by the ISA/CA dated Sep. 28, 2019. |
Number | Date | Country | |
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20200131864 A1 | Apr 2020 | US |
Number | Date | Country | |
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62535062 | Jul 2017 | US |