U.S. patent application number 17/432831 was filed with the patent office on 2022-05-19 for lockout mechanism for gripping tool.
The applicant listed for this patent is NOETIC TECHNOLOGIES INC.. Invention is credited to Maurice W. SLACK.
Application Number | 20220154540 17/432831 |
Document ID | / |
Family ID | 1000006316063 |
Filed Date | 2022-05-19 |
United States Patent
Application |
20220154540 |
Kind Code |
A1 |
SLACK; Maurice W. |
May 19, 2022 |
LOCKOUT MECHANISM FOR GRIPPING TOOL
Abstract
A secondary latch mechanism (also referred to as a lockout
mechanism) for a gripping tool, such as a casing running tool
(CRT), prevents activation of the CRT prior to full insertion of a
tubular workpiece into the CRT. When embodied in a CRT, the lockout
mechanism prevents activation of the CRT unless a fully-inserted
tubular workpiece applies a selected axial load to a bumper mounted
on the CRT. The lockout mechanism is operable between a locked
state and an unlocked state. In the locked state, the lockout
mechanism prevents relative axial movement between the CRT cage and
mandrel, and keeps the CRT slips retracted away from the workpiece.
When in the unlocked state, there is no significant restriction to
the normal movement of the CRT components, and the CRT functions as
if the lockout mechanism were not present.
Inventors: |
SLACK; Maurice W.;
(Edmonton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NOETIC TECHNOLOGIES INC. |
Edmonton |
CA |
US |
|
|
Family ID: |
1000006316063 |
Appl. No.: |
17/432831 |
Filed: |
February 6, 2021 |
PCT Filed: |
February 6, 2021 |
PCT NO: |
PCT/CA2021/000008 |
371 Date: |
August 20, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62971733 |
Feb 7, 2020 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 19/07 20130101 |
International
Class: |
E21B 19/07 20060101
E21B019/07 |
Claims
1. A lockout mechanism for a casing running tool (CRT) for gripping
a tubular workpiece, wherein said CRT has a longitudinal axis and
incorporates a generally cylindrical CRT cage having a CRT cage
wall; a generally cylindrical CRT mandrel coaxially aligned with
the CRT cage; and CRT slips carried by the CRT cage, said CRT slips
being radially movable in response to relative axial movement
between the CRT mandrel and the CRT cage to grip a selected surface
of the workpiece; and a primary CRT latch mechanism; and wherein
said lockout mechanism comprises: (a) a CRT bumper slidingly
mounted to the CRT cage and operable to axially stroke between a
locked position and an unlocked position, with said CRT bumper
being biased by a bumper spring configured to provide an axial
biasing force sufficient to resist a selected axial load when the
CRT bumper is moved from the locked position to the unlocked
position by contact with the end of the workpiece; (b) one or more
lock pins radially slidingly disposed in corresponding lock pin
guide holes through the CRT cage wall and movable between a locked
position, corresponding to the locked position of the CRT bumper,
in which the lock pins engage corresponding mandrel pockets formed
in the CRT mandrel, and an unlocked position, corresponding to the
unlocked position of the CRT bumper, in which the lock pins engage
corresponding bumper pockets formed in the CRT bumper; wherein: (c)
the mandrel pockets and the lock pin guide holes are arranged such
that the lock pins, when in their locked positions, will prevent
relative axial movement between the CRT mandrel and the CRT cage,
and will hold the CRT cage in an axial position relative to the CRT
mandrel wherein the CRT slips are retracted away from the
workpiece; (d) each mandrel pocket includes a cam surface
configured to induce movement of the lock pins toward their
unlocked positions when the CRT cage moves axially relative to the
CRT mandrel in the direction that causes the CRT slips to engage
the workpiece; (e) each bumper pocket includes a cam surface
configured to induce movement of the lock pins toward their locked
position in response to the axial force applied to the CRT bumper
by the bumper spring; (f) the axial biasing force of the bumper
spring is selected such that the bumper spring can apply sufficient
axial force to the CRT bumper to hold the lock pins in their locked
positions when no workpiece is in contact with the CRT bumper; and
(g) the application of an axial force by the workpiece to the CRT
bumper sufficient to axially stroke the CRT bumper and overcome the
axial biasing force of the bumper spring will move the CRT bumper
to its unlocked position, thereby allowing the lock pins to be
moved from their locked positions to their unlocked positions, and
into the corresponding bumper pockets.
2. The lockout mechanism as in claim 1, wherein the selected
surface of the workpiece is an external surface of the
workpiece.
3. The lockout mechanism as in claim 1, wherein the selected
surface of the workpiece is an internal surface of the
workpiece.
4. The lockout mechanism as in claim 1 further comprising a
mechanical linkage acting between the bumper and the CRT primary
latch mechanism such that axial force applied by the workpiece on
the bumper in excess of the axial biasing force of the bumper
spring will generate torque urging the CRT primary latch mechanism
to unlatch.
5. The lockout mechanism as in claim 4 wherein the mechanical
linkage comprises mating helical threads.
6. The lockout mechanism as in claim 4 wherein the mechanical
linkage comprises a helical track-follower.
7. The lockout mechanism as in claim 1 wherein the taper angles of
the cam surfaces of the bumper pockets and the mandrel pockets and
the axial biasing force of the bumper spring are selected so that
the lockout mechanism will automatically unlock in response to the
application of a selected combination of torque and axial load.
8. The lockout mechanism as in claim 1 wherein the bumper spring is
selected from the group consisting of coil springs, wave springs,
Belleville washer stacks, air springs, and hydraulic chambers
connected to accumulators.
Description
FIELD
[0001] The present disclosure relates in general to tools or
devices for gripping either the outward or inward facing surfaces
of a workpiece. In particular, the present disclosure relates to
oilfield tools, such as casing running tools (CRTs), used to grip
pipe, pipe couplings, or other tubular items with large tolerances
and with surface finishes typical of as-rolled steel, particularly
in circumstances where premature activation of the CRT prior to
full insertion of the workpiece into the CRT would be
undesirable.
BACKGROUND
[0002] U.S. Pat. No. 7,909,120 (Slack) describes
mechanically-activated tools for gripping tubular articles or
workpieces, and improvements to such tools are described in the
following patent documents: [0003] U.S. Pat. No. 8,424,939 (Slack);
[0004] U.S. Pat. No. 10,081,989 (Slack); [0005] International
Publication No. WO 2019/014747 A1 (Slack); and [0006] International
Publication No. WO 2020/146936 A1 (Slack).
[0007] CRTs based upon some of or all the above documents
incorporate a rotary (primary) latch mechanism that prevents
activation of the CRT when in the latched position and permits
activation of the CRT when unlatched. Unlatching the primary latch
mechanism may require some torque reaction, some compressive axial
load, or other remotely-controlled means. After the primary latch
mechanism is unlatched, the cage of the CRT may move axially
relative to the mandrel of the CRT and cause the slips assembly of
the CRT to grip the workpiece. Due to the variable nature of
drilling rig operations, pipe characteristics, and human
interaction with the drilling rig environment, the primary latch
mechanism may become unintentionally unlatched during pipe handling
operations, including casing running and casing drilling, and thus
result in undesirable activation of the CRT.
[0008] A typical normal activation operating sequence for a CRT
involves the following steps: [0009] 1. lowering the CRT onto the
workpiece; [0010] 2. setting down vertical compressive load onto
the bumper of the CRT to generate friction between the bumper and
the casing; [0011] 3. applying right-hand torque and rotation to
the CRT to unlatch the rotary (primary) latch mechanism; and [0012]
4. raising the CRT to allow the CRT cage to move axially relative
to the CRT mandrel, which causes the CRT's slip assembly to
simultaneously extend radially into engagement with the surface of
the workpiece.
[0013] It is advantageous to reduce the time required to activate
the CRT to decrease well construction time and cost. This can be
accomplished either operationally or mechanically. One method used
by drillers to increase operating speed is to rotate the CRT while
lowering it onto the workpiece, thus merging the first three steps
of the normal activation sequence into a single step, which
eliminates the associated transition time between set-down and
rotation. Another method for increasing operating speeds is to
mechanically eliminate the need to rotate the CRT after set-down
through use of a rotary latch release mechanism such as that
described in WO 2019/014747 A1 and WO 2020/146936 A1. Both of these
methods for reducing the time to activate the CRT can increase the
risk of unintentional and undesirable CRT activation resulting from
contact with a workpiece prior to full insertion of the workpiece
into the CRT or from general contact with other objects.
[0014] For purposes of this 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. The mandrel of a
CRTi and the bell of a CRTe serve similar functions, and for that
reason either of these elements may be alternatively referred to
herein as a CRT mandrel.
BRIEF SUMMARY OF THE DISCLOSURE
[0015] In general terms, the present disclosure teaches
non-limiting embodiments of a secondary latch mechanism
(alternatively referred to herein as a lockout mechanism) that
prevents activation of a gripping tool, such as a CRT, prior to
full insertion of a tubular workpiece (e.g., a section of pipe)
into the gripping tool. When embodied in a CRT, the lockout
mechanism prevents activation of the CRT unless a selected axial
load is applied to the CRT bumper by the end of a fully-inserted
workpiece.
[0016] In the remainder of this specification, lockout mechanisms
will be described for exemplary purposes in the context of
mechanically-activated casing running tools (CRTs) generally as
disclosed in U.S. Pat. No. 7,909,120, and the terms CRT, CRTe, and
CRTi will refer to such casing running tools unless specifically
stated otherwise.
[0017] The lockout mechanism has two operational states, namely, a
locked state and an unlocked state, and incorporates means for
transitioning between these two operational states. In the locked
state, the lockout mechanism resists relative axial movement
between the CRT cage and the CRT mandrel, and keeps the CRT slips
retracted away from the workpiece. The unlocked state is
characterized by the absence of any significant restriction to the
normal movement of the components of the CRT. In the unlocked
state, the CRT functions as if the lockout mechanism were not
present.
[0018] There are two separate means for transitioning the lockout
mechanism from the locked state to the unlocked state: [0019] 1.
Application of axial load to the CRT bumper that exceeds an axial
biasing force provided by a bumper spring comprising one or more
bumper spring elements; and [0020] 2. Optionally, application of a
hoist load (which may also be generated by torque) to the lockout
mechanism that exceeds a selected threshold.
[0021] The lockout mechanism will return to the locked state from
the unlocked state when the following operational sequence is
performed: [0022] 1. The CRT slips are retracted from the workpiece
by application of set-down load, requisite torque, or other means;
[0023] 2. The primary latch mechanism of the CRT is placed in the
latched position by application of requisite set-down load and
rotation; and [0024] 3. The CRT is raised so that the CRT bumper no
longer contacts the upper end of the workpiece.
[0025] In general terms, a lockout mechanism in a CRT in accordance
with the present disclosure comprises: [0026] a CRT bumper
slidingly mounted to the CRT cage and operable to axially stroke
between a first (or locked) position to a second (or unlocked)
position, with the CRT bumper being biased by a bumper spring
configured to provide an axial biasing force sufficient to resist a
selected axial load when the CRT bumper is moved from the locked
position to the unlocked position by contact with the end of the
workpiece; [0027] one or more lock pins [0028] a lock pin guide
hole through the CRT cage wall for each lock pin, for receiving the
lock pin and guiding it between its locked and unlocked positions;
[0029] one or more mandrel pockets (which may be provided in the
form of one or more grooves) in the CRT mandrel, configured for
receiving the lock pins when the lockout mechanism is in the locked
state; and [0030] one or more bumper pockets (which may be provided
in the form of one or more grooves) in the CRT bumper, configured
for receiving the lock pins when the lockout mechanism is in the
unlocked state.
[0031] As used in the present disclosure, the term "bumper spring"
is intended to be understood as denoting an element or apparatus
capable of providing an axial biasing force, and which therefore
may take any functionally suitable form without departing for the
scope of the present disclosure. Non-limiting examples of a bumper
spring in accordance with the present disclosure include coil
springs, wave springs, Belleville washer stacks, air springs, and
hydraulic chambers connected to accumulators.
[0032] The mandrel pockets and the holes through the CRT cage wall
are arranged such that the lock pins in their locked positions will
prevent relative axial movement between the CRT mandrel and the CRT
cage, and will hold the CRT cage in a position relative to the CRT
mandrel where the CRT slips are retracted away from the
workpiece.
[0033] The mandrel pockets include a cam surface configured to
induce movement of the lock pins toward their unlocked positions
when the CRT cage moves axially relative to the CRT mandrel in the
direction that causes the CRT slips to engage the workpiece.
[0034] The bumper pockets include a cam surface configured to
induce movement of the lock pins toward their locked position due
to an axial force applied to the CRT bumper by the bumper spring.
The stiffness and length of the bumper spring are selected such
that the bumper spring provides sufficient axial force to hold the
lock pins in their locked positions when no workpiece is in contact
with the CRT bumper.
[0035] When a pipe or other tubular workpiece applies an axial
force to the CRT bumper exceeding the axial biasing force of the
bumper spring, the CRT bumper will move to its unlocked position,
permitting the lock pins to move from their locked position to
their unlocked position, and into the bumper pockets. The axial
biasing force of the bumper spring is determined by the spring
stiffness and pre-load. If the primary latch mechanism of the CRT
is unlatched and the CRT is raised while the CRT bumper is in its
unlocked position, then the CRT cage will be able to move axially
relative to the CRT mandrel such that the slips will engage the
workpiece. If the primary latch mechanism of the CRT is latched and
the CRT is raised while the CRT bumper is in its unlocked position,
then the CRT cage will not be able to move axially relative to the
CRT mandrel, so the bumper spring will urge the CRT bumper to
return to its locked position and urge the lock pins to return to
their locked positions.
[0036] The lockout mechanism may be configured with a mechanical
linkage acting between the bumper and the primary latch mechanism
such that axial force applied by the workpiece on the bumper in
excess of the axial biasing force of the bumper spring generates
torque urging the primary latch mechanism to unlatch. Non-limiting
examples of mechanical linkages that convert axial force (and
associated linear motion) to torque (and associated rotary motion)
include mating helical threads and helical track followers.
[0037] The lockout mechanism may be configured to automatically
unlock at a selected combined torque and axial load envelope
(alternatively referred to herein as a lockout release envelope),
provided that the selected lockout release envelope is sufficient
to unlatch the primary latch of the CRT. The lockout release
envelope required to automatically unlock the lockout mechanism
will be determined by the force balance on the lock pins--which
includes the selected taper angles of the cam surfaces of the
bumper pockets and mandrel pockets, and the axial biasing force of
the bumper spring. The taper angle of the cam surfaces in the
bumper pockets and mandrel pockets may be selected to remain
constant, or to vary along the length of the cam surface to alter
the axial and radial components of the contact forces with the lock
pins as the mechanism components move relative to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Embodiments in accordance with the present disclosure will
now be described with reference to the accompanying figures, in
which numerical references denote like parts, and in which:
[0039] FIG. 1 is a schematic view of an exemplary embodiment of a
lockout mechanism in accordance with the present disclosure and
incorporated into a CRTe, with the CRTe being shown lowered onto a
tubular workpiece and prior to the top of the workpiece contacting
the CRT bumper.
[0040] FIG. 2 is a schematic view of the lockout mechanism in FIG.
1, shown when the top of the workpiece contacts the CRT bumper
without sufficient force to compress the bumper spring.
[0041] FIG. 3 is a schematic view of the lockout mechanism in FIG.
1, shown when the CRT bumper has stroked to its unlocked position
and the bumper spring is compressed.
[0042] FIG. 4 is a schematic view of the lockout mechanism in FIG.
1, shown after the primary latch mechanism has been unlatched and
the CRTe has been raised sufficiently to cause the lock pins to
move from their locked positions to their unlocked positions.
[0043] FIG. 5 is a schematic view of the lockout mechanism in FIG.
1, shown when the CRTe has been raised sufficiently to cause the
slips of the CRTe to engage the workpiece.
[0044] FIG. 6 is a schematic view of the lockout mechanism in FIG.
1, shown after the CRT has been lowered to release the
workpiece.
[0045] FIG. 7 is a schematic view of an exemplary embodiment of a
lockout mechanism in accordance with the present disclosure and
incorporated into a CRTi, with the CRTi being shown lowered onto a
tubular workpiece and prior to the top of the workpiece contacting
the CRT bumper.
[0046] FIG. 8 is a schematic view of the lockout mechanism in FIG.
7, shown when the top of the workpiece contacts the CRT bumper
without sufficient force to compress the bumper spring.
[0047] FIG. 9 is a schematic view of the lockout mechanism in FIG.
7, shown when the CRT bumper has stroked to its unlocked position
and the bumper spring is compressed.
[0048] FIG. 10 is a schematic view of the lockout mechanism in FIG.
7, shown after the primary latch mechanism has been unlatched and
when CRTi has been raised sufficiently to cause the lock pins to
move from their locked positions to their unlocked positions.
[0049] FIG. 11 is a schematic view of the lockout mechanism in FIG.
7, shown when the CRTi has been raised sufficiently to cause the
slips to engage the workpiece.
[0050] FIG. 12 is a schematic view of the lockout mechanism in FIG.
7, shown after the CRTi has been lowered to release the
workpiece.
[0051] FIG. 13 is a cross-section through a CRTe generally in
accordance with U.S. Pat. No. 7,909,120, similar to a CRTe shown in
U.S. Pat. No. 10,081,989, and including an embodiment of a lockout
mechanism in accordance with the present disclosure.
[0052] FIG. 14 is a sectional detail of the lockout mechanism of
FIG. 13 along a plane showing the lock pins in their locked
positions.
[0053] FIG. 15 is a sectional detail of the lockout mechanism of
FIG. 13 along a plane showing the lock pins in their unlocked
positions.
[0054] FIG. 16 is a sectional detail of the lockout mechanism of
FIG. 13 along a plane showing the bumper spring.
[0055] FIG. 17 is a sectional detail of the lockout mechanism of
FIG. 13 along a plane showing shoulder bolts securing the CRT
bumper to the CRT cage assembly.
[0056] FIG. 18 is a partial cross-section through a CRTe generally
in accordance with U.S. Pat. No. 7,909,120, similar to a CRTe shown
in WO 2020/146936 A1, and including another embodiment of a lockout
mechanism in accordance with the present disclosure. The radially
outward parts are sectioned and the parts near the central axis are
not sectioned.
[0057] FIG. 19 is a partial sectional detail of the lockout
mechanism and rotary (primary) latch mechanism of FIG. 18 showing
the lock pins in their locked positions and the primary latch
mechanism in its latched position.
[0058] FIG. 20 is a partial sectional detail of the lockout
mechanism and rotary (primary) latch mechanism of FIG. 18 showing
the lock pins in their unlocked positions and the primary latch
mechanism in its unlatched position.
DETAILED DESCRIPTION
[0059] Exemplary Embodiment Incorporated into a CRTe
[0060] FIGS. 1 through 6 schematically illustrate the operation of
one embodiment of a lockout mechanism in accordance with the
present disclosure, and incorporated into a CRTe 120 generally in
accordance with the teachings of U.S. Pat. No. 7,909,120.
[0061] FIG. 1 is a schematic view showing CRTe 120 as it is being
lowered by the top drive of a drilling rig (not shown) onto a
workpiece 110 (such as a section of pipe), and prior to the top of
workpiece 110 contacting the bumper 150 of CRTe 120. Bumper spring
151 urges bumper 150 and lock pins 170 toward their respective
locked positions. Cage spring 143 (which may be an air spring) is
compressed between CRT mandrel 130 and CRT cage 140. Primary latch
mechanism 134 is in its latched position, preventing CRT cage 140
from moving axially away from CRT mandrel 130 due to the force of
compressed cage spring 143. CRT slips 160 are fully retracted away
from workpiece 110.
[0062] FIG. 2 is a schematic view of CRTe 120 after it has been
further lowered such that the top of workpiece 110 contacts CRT
bumper 150 without sufficient force to compress bumper spring
151.
[0063] FIG. 3 is a schematic view of CRTe 120 shown at the point
when CRTe 120 has been further lowered such that bumper spring 151
is compressed and CRT bumper 150 is in its unlocked position
relative to CRT cage 140. Primary latch mechanism 134 (which is a
rotary latch mechanism) can be unlatched by using the top drive to
apply set-down load and then to rotate CRT mandrel 130 in a first
direction.
[0064] FIG. 4 is a schematic view of CRTe 120 shown after primary
latch mechanism 134 has been unlatched, and after CRTe 120 has been
raised sufficiently to cause the lock pins 170 to move from their
locked positions to their unlocked positions, urged by cam surfaces
132 of mandrel pockets 131 in CRT mandrel 130 and received by
bumper pockets 152 in CRT bumper 150. Due to the relative axial
motion between CRT mandrel 130 and CRT cage 140, CRT slips 160
extend toward workpiece 110.
[0065] FIG. 5 is a schematic view of CRTe 120 at the point where it
has been raised sufficiently to cause CRT slips 160 to engage
workpiece 110.
[0066] FIG. 6 is a schematic view of CRTe 120 after it has been
lowered to release workpiece 110. Primary latch mechanism 134 can
be latched by applying set-down load and rotating CRT mandrel 130
in a second direction. After primary latch mechanism 134 has been
latched, raising CRTe 120 will allow CRT bumper 150 to move to its
locked position relative to CRT cage 140, urged by bumper spring
151. Cam surfaces 153 of bumper pockets 152 urge lock pins 170 to
their locked position, received by mandrel pockets 131 in CRT
mandrel 130. The state of CRTe 120 will then have returned to the
state shown in FIG. 2.
[0067] If CRTe 120 is rotated while being lowered onto workpiece
110 and is misaligned with workpiece 110, then torque and axial
load may be transmitted through contact between CRT slips 160 and
workpiece 110 prior to workpiece 110 contacting CRT bumper 150. If
the combined torque and axial load transmitted through the contact
between CRT slips 160 and workpiece 110 is sufficient to unlatch
the primary latch mechanism, the lockout mechanism will prevent
relative axial movement between CRT cage 140 and CRT mandrel 130,
which would extend CRT slips 160 toward workpiece 110.
[0068] The lockout mechanism may be configured to automatically
unlock at a selected combined axial load and torque envelope
(alternatively referred to as the lockout release envelope). The
lockout release envelope is determined by the force balance on lock
pins 170, which includes the selected taper angles of cam surface
153 of bumper pockets 152 and cam surface 132 of mandrel pockets
131, and the axial biasing force of bumper spring 151.
Exemplary Embodiment Incorporated into a CRTi
[0069] FIGS. 7 through 12 schematically illustrate the operation of
an exemplary embodiment of a lockout mechanism in accordance with
the present disclosure, and incorporated into a CRTi 220 generally
in accordance with the teachings of U.S. Pat. No. 7,909,120.
[0070] FIG. 7 is a schematic view showing CRTi 220 as it is being
lowered by the top drive of a drilling rig (not shown) onto a
workpiece 210, and prior to the top of workpiece 210 contacting the
CRT bumper 250 of CRTi 220. Bumper spring 251 urges CRT bumper 250
and lock pins 270 toward their respective locked positions. Cage
spring 243 (which may be an air spring) is compressed between CRT
mandrel 230 and CRT cage 240. Primary latch mechanism 234 is in its
latched position, preventing CRT cage 240 from moving axially away
from CRT mandrel 230 due to the force of compressed cage spring
243. CRT slips 260 are fully retracted away from workpiece 210.
[0071] FIG. 8 is a schematic view of CRTi 220 after it has been
further lowered such that the top of workpiece 210 contacts CRT
bumper 250 without sufficient force to compress bumper spring
251.
[0072] FIG. 9 is a schematic view of CRTi 220 shown at the point
when CRTi 220 has been further lowered such that bumper spring 251
is compressed and CRT bumper 250 is in its unlocked position
relative to CRT cage 240. Primary latch mechanism 234 (which is a
rotary latch mechanism) can be unlatched by using the top drive to
apply set-down load and then rotating CRT mandrel 230 in a first
direction.
[0073] FIG. 10 is a schematic view of CRTi 220 shown after primary
latch mechanism 234 has been unlatched, and after CRTi 220 has been
raised sufficiently to cause the lock pins 270 to move from their
locked positions to their unlocked positions, urged by cam surfaces
232 of mandrel pockets 231 in CRT mandrel 230 and received by
bumper pockets 252 in CRT bumper 250. Due to the relative axial
motion between CRT mandrel 230 and CRT cage 240, CRT slips 260
extend toward workpiece 210.
[0074] FIG. 11 is a schematic view of CRTi 220 at the point where
it has been raised sufficiently to cause CRT slips 260 to engage
workpiece 210.
[0075] FIG. 12 is a schematic view of CRTi 220 after it has been
lowered to release workpiece 210. Primary latch mechanism 234 can
be latched by applying set-down load and rotating CRT mandrel 230
in a second direction. After primary latch mechanism 234 has been
latched, raising CRTe 220 will allow CRT bumper 250 to move to its
locked position relative to CRT cage 240, urged by bumper spring
251. Cam surfaces 253 of bumper pockets 252 urge lock pins 270 to
their locked positions, received by pockets 231 of CRT mandrel 230.
The state of CRTi 220 will then have returned to the state shown in
FIG. 8.
[0076] If CRTi 220 is rotated while being lowered onto workpiece
210 and is misaligned with workpiece 210, then torque and axial
load may be transmitted through contact between CRT slips 260 and
workpiece 210 prior to workpiece 210 contacting CRT bumper 250. If
the combined torque and axial load transmitted through the contact
between CRT slips 260 and workpiece 210 is sufficient to unlatch
the primary latch mechanism, the lockout mechanism will prevent
relative axial movement between CRT cage 240 and CRT mandrel 230,
which would extend CRT slips 260 toward workpiece 210.
[0077] The lockout mechanism may be configured to automatically
unlock at a selected lockout release envelope determined by the
force balance on lock pins 270, which includes the selected taper
angles of cam surface 253 of bumper pockets 252 and cam surface 232
of mandrel pockets 231, and the axial biasing force of bumper
spring 251.
Physical Embodiment Incorporated into a CRTe
[0078] FIG. 13 is a cross-section of a CRTe 320 generally in
accordance with the teachings of U.S. Pat. No. 7,909,120; similar
to a CRTe shown in U.S. Pat. No. 10,081,989; and including an
embodiment of a lockout mechanism in accordance with this
specification. Primary latch mechanism 334 of CRTe 320 is a rotary
latch similar to that shown in U.S. Pat. No. 8,424,939. Cage spring
343 is an air spring. CRT mandrel 330, CRT cage 340, and CRT slips
360 are assemblies of multiple parts. The state of CRTe 320 and
this lockout mechanism in FIG. 13 is similar to the state shown in
FIG. 2 for CRTe 120, with lock pins 370 in their locked positions
and with workpiece 310 in initial contact with bumper 350.
[0079] FIG. 14 is a sectional detail of the lockout mechanism in
CRTe 320 along a plane showing lock pins 370 in their locked
positions, and bumper pockets 352 in CRT bumper 350 and mandrel
pockets 331 in CRT mandrel assembly 330. The state of this lockout
mechanism in CRTe 320 in FIG. 14 is similar to the state shown in
FIG. 2 for the lockout mechanism of CRTe 120.
[0080] FIG. 15 is a sectional detail of the lockout mechanism in
CRTe 320 along a plane showing lock pins 370 in their unlocked
positions, and bumper pockets 352 in CRT bumper 350 and mandrel
pockets 331 in CRT mandrel assembly 330. The state of this lockout
mechanism in CRTe 320 in FIG. 15 is similar to the state shown in
FIG. 4 for the lockout mechanism of CRTe 120.
[0081] FIG. 16 is a sectional detail of the lockout mechanism in
CRTe 320 along a plane showing bumper springs 351. When a workpiece
(not shown in FIG. 16) applies sufficient axial force to the lower
surface of CRT bumper 350, bumper springs 351 are compressed
between CRT bumper 350 and CRT cage assembly 340 as CRT bumper 350
strokes from its locked position to its unlocked position.
[0082] FIG. 17 is a sectional detail of the lockout mechanism in
CRTe 320 along a plane showing shoulder bolts 354 securing CRT
bumper 350 to CRT cage assembly 340.
Secondary Latch Mechanism with Primary Latch Release Function
[0083] FIG. 18 is a cross-section through a CRTe 420 generally in
accordance with the teachings of U.S. Pat. No. 7,909,120 (similar
to a CRTe shown in U.S. Pat. No. 10,081,989) and including another
embodiment of a lockout mechanism in accordance with the present
disclosure. Primary latch mechanism 434 of CRTe 420 is a rotary
latch similar to that shown in U.S. Pat. No. 8,424,939, comprising
upper latch hooks 435 and lower latch hooks 436. Cage spring 443 is
an air spring. CRT mandrel 430, CRT cage 440, and CRT slips 460 are
assemblies of multiple parts. The state of CRTe 420 and the lockout
mechanism in FIG. 18 is similar to the state shown in FIG. 1 for
CRTe 120, with lock pins 470 in their locked positions, primary
latch mechanism 434 in its latched position, and with workpiece 410
prior to initial contact with CRT bumper 450.
[0084] FIG. 19 is a partial sectional detail of the lockout
mechanism and primary latch mechanism 434 in CRTe 420, showing lock
pins 470 in their locked positions; primary latch mechanism 434 in
its latched position; bumper pockets 452 in CRT bumper 450; and
mandrel pockets 431 in CRT mandrel assembly 430. The state of this
lockout mechanism in CRTe 420 in FIG. 19 is similar to the state
shown in FIG. 1 for the lockout mechanism of CRTe 120.
[0085] FIG. 20 is a partial sectional detail of the lockout
mechanism and primary latch mechanism 434 of CRTe 420 showing lock
pins 470 in their unlocked positions; primary latch mechanism 434
in its unlatched position; bumper pockets 452 in CRT bumper 450;
and CRT mandrel pockets 431 in CRT mandrel assembly 430. The state
of this lockout mechanism in CRTe 420 in FIG. 20 is similar to the
state shown in FIG. 3 for the lockout mechanism of CRTe 120.
[0086] The lockout mechanism of CRTe 420 is configured with a
mechanical linkage 445 acting between CRT bumper 450 and primary
latch mechanism 434 such that axial force applied by workpiece 410
on CRT bumper 450 in excess of the axial biasing force of bumper
spring 451 generates torque urging primary latch mechanism 434 to
unlatch. Mechanical linkage 445 comprises track followers 444 on a
radially-inward surface of CRT cage 440 that engage helical tracks
455 in a radially-outward surface of CRT bumper 450. The torque
generated by mechanical linkage 445 is transmitted from track
followers 444 to CRT cage 440 and then to lower latch hooks 436 of
primary latch mechanism 434. The torque generated by mechanical
linkage 445 is also transmitted from helical tracks 455 in CRT
bumper 450 to workpiece 410 through frictional contact with CRT
bumper 450 to the drilling rig (not shown) to the upper end of CRTe
420, and then to upper latch hooks 435 of primary latch mechanism
434.
[0087] It will be readily appreciated by those skilled in the art
that various modifications to embodiments in accordance with the
present disclosure may be devised without departing from the scope
of the present teachings, including modifications that use
equivalent structures or materials hereafter conceived or
developed.
[0088] It is especially to be understood that the scope of the
present disclosure is not intended to be limited to described or
illustrated embodiments, and that the substitution of a variant of
any claimed or illustrated element or feature, without any
substantial resultant change in functionality, will not constitute
a departure from the scope of the disclosure.
[0089] In this patent document, any form of the word "comprise" is
to be understood in its non-limiting sense to mean that any element
or feature following such word is included, but elements or
features not specifically mentioned are not excluded. A reference
to an element or feature by the indefinite article "a" does not
exclude the possibility that more than one such element or feature
is present, unless the context clearly requires that there be one
and only one such element or feature.
[0090] Any use herein of any form of the terms "connect", "engage",
"couple", "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.
[0091] Relational and conformational terms such as (but not limited
to) "axial" and "cylindrical" 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 axial" or "generally
cylindrical") unless the context clearly requires otherwise.
[0092] Unless specifically noted otherwise, any reference to an
element being "generally cylindrical" is intended to denote that
the element in question would appear substantially cylindrical in
transverse cross-section, although the cross-sectional
configuration of the element may vary along its length.
[0093] 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.
TABLE-US-00001 LIST OF ILLUSTRATED ELEMENTS Element Number
Description 110 Workpiece 120 CRTe 130 CRT mandrel 131 Mandrel
pocket in CRT mandrel 130 132 Cam surface of mandrel pocket 131 134
Primary latch mechanism 140 CRT cage 143 Cage spring 150 CRT bumper
151 Bumper spring 152 Bumper pocket in CRT bumper 150 153 Cam
surface of bumper pocket 152 160 CRT slip 170 Lock pin 210
Workpiece 220 CRTi 230 CRT mandrel 231 Mandrel pocket in CRT
mandrel 230 232 Cam surface of mandrel pocket 231 234 Primary latch
mechanism 240 CRT cage 243 Cage spring 250 CRT bumper 251 Bumper
spring 252 Bumper pocket in CRT bumper 250 253 Cam surface of
bumper pocket 252 260 CRT slip 270 Lock pin 310 Workpiece 320 CRTi
330 CRT mandrel 331 Mandrel pocket in CRT mandrel 330 332 Cam
surface of mandrel pocket 331 334 Primary latch mechanism 340 CRT
cage 343 Cage spring 350 CRT bumper 351 Bumper spring 352 Bumper
pocket in CRT bumper 350 353 Cam surface of bumper pocket 352 354
Shoulder bolt 360 CRT slip 370 Lock pin 410 Workpiece 420 CRTi 430
CRT mandrel 431 Mandrel pocket in CRT mandrel 430 432 Cam surface
of mandrel pocket 431 434 Primary latch mechanism 435 Upper latch
hooks 436 Lower latch hooks 440 CRT cage 443 Cage spring 444 Track
follower 445 Mechanical linkage 450 CRT bumper 451 Bumper spring
452 Bumper pocket in CRT bumper 450 453 Cam surface of bumper
pocket 452 454 Shoulder bolt 455 Helical track 460 CRT slip 470
Lock pin
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