U.S. patent application number 15/273983 was filed with the patent office on 2018-03-29 for worm-drive power tong.
The applicant listed for this patent is Frank's International, LLC. Invention is credited to Timothy Bernard, Vernon Bouligny.
Application Number | 20180087334 15/273983 |
Document ID | / |
Family ID | 61687241 |
Filed Date | 2018-03-29 |
United States Patent
Application |
20180087334 |
Kind Code |
A1 |
Bouligny; Vernon ; et
al. |
March 29, 2018 |
WORM-DRIVE POWER TONG
Abstract
A tong for applying torque to a tubular and a method of using a
tong, of which the tong includes a rotary ring defining an inner
profile through which the tubular is received, the inner profile
defining a plurality of pockets extending radially outward and a
plurality of cam surfaces circumferentially between the plurality
of pockets, and a plurality of engaging members disposed within the
rotary ring. The plurality of engaging members are movable from a
retracted position at least partially in the plurality of pockets
to an engaging position in which the plurality of engaging members
are positioned along the plurality of cam surfaces. The tong also
includes a plurality of cam followers extending through the rotary
ring, and a worm drive including a helical ridge. The plurality of
cam followers engage the helical ridge so as to transmit a
substantially tangential force to the rotary ring.
Inventors: |
Bouligny; Vernon; (New
Iberia, LA) ; Bernard; Timothy; (Youngsville,
LA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Frank's International, LLC |
Houston |
TX |
US |
|
|
Family ID: |
61687241 |
Appl. No.: |
15/273983 |
Filed: |
September 23, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 19/164 20130101;
F16H 1/166 20130101; F16H 1/225 20130101 |
International
Class: |
E21B 19/16 20060101
E21B019/16 |
Claims
1. A tong for applying torque to a tubular, comprising: a rotary
ring defining an inner profile through which the tubular is
received, the inner profile defining a plurality of pockets
extending radially outward and a plurality of cam surfaces
circumferentially between the plurality of pockets; a plurality of
engaging members disposed within the rotary ring, wherein the
plurality of engaging members are movable from a retracted position
at least partially in the plurality of pockets to an engaging
position in which the plurality of engaging members are positioned
along the plurality of cam surfaces; a plurality of cam followers
extending through the rotary ring; and a worm drive comprising a
helical ridge, wherein the plurality of cam followers engage the
helical ridge so as to transmit a substantially tangential force to
the rotary ring, to rotate the rotary ring.
2. The tong of claim 1, wherein the plurality of cam surfaces each
comprise an arcuate shape.
3. The tong of claim 1, wherein the plurality of engaging members
each comprise a roller that rolls along one of the plurality of cam
surfaces when the rotary ring is rotated relative to the engaging
members.
4. The tong of claim 1, wherein the plurality of cam surfaces each
define a stepped profile comprising a first arcuate surface, a
second arcuate surface, and a transition ramp positioned
therebetween.
5. The tong of claim 1, wherein the plurality of engaging members
are configured to rotate with the rotary ring after moving along at
least a portion of the plurality of camming surfaces.
6. The tong of claim 1, further comprising a cage plate coupled to
the rotary ring, wherein the plurality of engaging members are
coupled to the cage plate such that the plurality of engaging
members are slidable with respect to the cage plate in a radial
direction, but are prevented from moving circumferentially relative
to the cage plate.
7. The tong of claim 6, wherein the cage plate comprises a
plurality of radial slots, the radial slots slidably receiving the
engaging members.
8. The tong of claim 6, further comprising: a stationary body, the
rotary ring being rotatable relative to the stationary body; and a
brake band coupled to the stationary body and received at least
partially around the cage plate, to apply a friction force on the
cage plate that resists rotation of the cage plate relative to the
stationary body.
9. The tong of claim 8, wherein a portion of the rotary ring and a
portion of the stationary body are movable to allow lateral removal
of the tubular from within the rotary ring.
10. The tong of claim 8, wherein the rotary ring defines one or
more arcuate backing slots, the tong further comprising: a top
guard comprising openings, wherein the cage plate comprises a make
pinhole and a break pinhole, the make pinhole being aligned with
one of the openings and the break pinhole being aligned with
another one of the openings; and a backing pin received through one
of the openings and through the make pinhole or the break pinhole,
and into the backing slot, wherein the backing pin in the backing
slot limits a range of relative rotation between the cage plate and
the rotary ring.
11. The tong of claim 1, wherein the plurality of cam followers
each comprise a first roller configured to engage the helical
ridge, a second roller seated on the rotary ring, and a shaft
extending therebetween.
12. The tong of claim 1, wherein the plurality of cam followers
extend axially into the rotary ring and the helical ridge and the
rotary ring are radially overlapping.
13. A method for rotating a tubular using a tong, comprising:
receiving a tubular into a receiving hole in a tong; and activating
a motor, wherein activating the motor causes a helical ridge to
rotate in a first direction, the helical ridge applying a linear
force on one or more cam followers connected to a rotary ring,
causing the rotary ring to rotate relative to a plurality of
engaging members, wherein rotating the rotary ring relative to the
plurality of engaging members causes the plurality of engaging
members to move radially inwards into engagement with the tubular
and to rotate the tubular after engaging the tubular.
14. The method of claim 13, further comprising reversing a
direction of the motor, wherein reversing the direction of the
motor causes the helical ridge to rotate in a second direction,
opposite to the first direction, which causes the rotary ring to
rotate in a reverse direction, wherein the rotary ring rotating in
the reverse direction allows the plurality of engaging members to
retract radially outwards.
15. The method of claim 14, further comprising laterally removing
the tubular from within the rotary ring, after reversing the
direction of the motor.
16. The method of claim 14, further comprising axially removing the
tubular from within the rotary ring, after reversing direction of
the motor.
17. The method of claim 14, further comprising, after activating
the motor and before reversing the direction of the motor:
de-activating the motor; removing a backing pin from a slot formed
in the rotary ring and from a make opening defined in a cage plate
that is aligned with the slot, wherein the cage plate is connected
to the plurality of engaging members such that the engaging members
are slidable radially with respect thereto, but prevented from
moving circumferentially with respect thereto; and inserting the
backing pin through a break opening aligned with the slot and into
the slot, wherein the backing pin limits a relative rotation
between the rotary ring and the cage plate by engaging the
slot.
18. The method of claim 17, wherein the cage plate is initially
prevented from rotating with the rotary ring by a brake band
connected to a stationary body of the tong, and wherein the cage
plate is rotatable relative to the stationary body when a friction
force applied by the brake band on the cage plate is overcome.
19. The method of claim 14, wherein the plurality of engaging
members retract radially outward into respective pockets formed in
the rotary ring.
20. A tong, comprising: a motor; a helical ridge coupled to the
motor such that the motor drives the helical ridge to rotate; a
rotary ring defining a plurality of pockets and a plurality of cam
surfaces in an inner profile thereof; a plurality of cam followers
connected to the rotary ring and extending axially therefrom, the
plurality of cam followers being positioned to be engaged by the
helical ridge, wherein the helical ridge applies a linear force on
the plurality of cam followers when the cam followers are engaged
by the helical ridge, and wherein the linear force causes the
rotary ring to rotate; and a plurality of jaws movable along the
inner profile of the rotary ring, wherein the plurality of jaws are
positioned at least partially within respective pockets of the
plurality of pockets when the tong is in a retracted position, and
wherein the plurality of jaws engage the plurality of cam surfaces
when the tong is in an engaging position.
21. The tong of claim 20, wherein the rotary ring comprises a
removable section to allow lateral removal of a tubular from within
the inner profile of the rotary ring.
Description
BACKGROUND
[0001] Tubular handling equipment is used on an oil rig to lower
casing and other tubulars into the wellbore ("trip-in"). During
trip-in, an elevator picks up a length of one or more joints of
tubular from a rack and brings the tubular into position above a
"stump" or open connection of a previously-run tubular. The stump
is typically supported at the rig floor by a spider, which
transmits the weight of the deployed tubular string to the rig
floor. An operator may then guide the new length of tubular (an
"add-on" tubular) into position over the stump, i.e., at well
center. The operator may then assist in stabbing the add-on tubular
into the open connection of the stump.
[0002] Once this occurs, the operator may engage a power tong onto
the add-on tubular and apply a torque to the add-on tubular. The
torque causes the add-on tubular to rotate into connection with the
stump. The tong is then disengaged, the elevator engages the add-on
tubular, and the spider may disengage from the tubular string,
leaving the weight of the tubular string held by the elevator. The
elevator then lowers the tubular string into the well, until
nearing the rig floor, at which point the spider is re-engaged, and
the process starts again.
[0003] The aforementioned tongs are designed to impart and
withstand high torsional loads. Typically, a tong includes a drive
train made of a set of spur gears, which amplify a torque produced
by a motor. The amplified torque is then transmitted to a rotary
gear, which applies the torque to the tubular. Other tong designs
employ a worm-gear drive, in which a helical tooth mates with
canted teeth of a driven gear. Thus, rotation of the helical tooth
results in rotation of the driven gear, which the tong converts
into rotation of the tubular.
[0004] Conventional tongs, however, occupy a substantial footprint
on a rig. Further, tongs are typically designed to engage a single
diameter of pipe, requiring time-consuming equipment changes when
the size (diameter) of the pipe being run changes. Additionally,
tongs are often designed to allow lateral entry of the pipe to
within the tong and exit therefrom, but may not be configured to
allow a box-end of a pipe joint to pass axially therethrough.
SUMMARY
[0005] Embodiments of the disclosure may provide a tong for
applying torque to a tubular. The tong includes a rotary ring
defining an inner profile through which the tubular is received,
the inner profile defining a plurality of pockets extending
radially outward and a plurality of cam surfaces circumferentially
between the plurality of pockets, and a plurality of engaging
members disposed within the rotary ring. The plurality of engaging
members are movable from a retracted position at least partially in
the plurality of pockets to an engaging position in which the
plurality of engaging members are positioned along the plurality of
cam surfaces. The tong also includes a plurality of cam followers
extending through the rotary ring, and a worm drive including a
helical ridge. The plurality of cam followers engage the helical
ridge so as to transmit a substantially tangential force to the
rotary ring.
[0006] Embodiments of the disclosure may also provide a method for
rotating a tubular using a tong. The method includes receiving a
tubular into a receiving hole in a tong, and activating a motor.
Activating the motor causes a helical ridge to rotate in a first
direction, the helical ridge applying a linear force on one or more
cam followers connected to a rotary ring, causing the rotary ring
to rotate relative to a plurality of engaging members. Rotating the
rotary ring relative to the plurality of engaging members causes
the plurality of engaging members to move radially inwards into
engagement with the tubular and to rotate the tubular after
engaging the tubular.
[0007] Embodiments of the disclosure may further provide a tong
that includes a motor, a helical ridge coupled to the motor such
that the motor drives the helical ridge to rotate, a rotary ring
defining a plurality of pockets and a plurality of cam surfaces in
an inner profile thereof, and a plurality of cam followers
connected to the rotary ring and extending axially therefrom, the
plurality of cam followers being positioned to be engaged by the
helical ridge. The helical ridge applies a linear force on the
plurality of cam followers when the cam followers are engaged by
the helical ridge, and wherein the linear force causes the rotary
ring to rotate. The tong also includes a plurality of jaws movable
along the inner profile of the rotary ring. The plurality of jaws
are positioned at least partially within respective pockets of the
plurality of pockets when the tong is in a retracted position, and
the plurality of jaws engage the plurality of cam surfaces when the
tong is in an engaging position.
[0008] The foregoing summary is intended merely to introduce a
subset of the features more fully described of the following
detailed description. Accordingly, this summary should not be
considered limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawing, which is incorporated in and
constitutes a part of this specification, illustrates an embodiment
of the present teachings and together with the description, serves
to explain the principles of the present teachings. In the
figures:
[0010] FIG. 1 illustrates a perspective view of a power tong,
according to an embodiment.
[0011] FIG. 2A illustrates another perspective view of the tong
showing a worm-drive thereof, according to an embodiment.
[0012] FIG. 2B illustrates a simplified bottom view of the tong,
showing another embodiment of the worm drive.
[0013] FIG. 3 illustrates a perspective view of the tong with a top
guard thereof removed, revealing a cage plate thereof, according to
an embodiment.
[0014] FIG. 4 illustrates a perspective view of the tong with the
top guard and the cage plate removed, according to an
embodiment.
[0015] FIG. 5 illustrates a top view of the tong with the top guard
and cage plate removed, showing a first embodiment of the jaws,
according to a first embodiment.
[0016] FIG. 6A illustrates a perspective view of a cage plate of
the tong with jaws retracted, according to an embodiment.
[0017] FIG. 6B illustrates another perspective view of the cage
plate of the tong with jaws extended radially inward, according to
an embodiment.
[0018] FIG. 6C illustrates a sectional view of the tong, according
to an embodiment.
[0019] FIG. 7 illustrates a top, schematic view of a second
embodiment of a cam surface of the tong.
[0020] FIG. 8 illustrates a top view of the tong with the jaws in a
retracted configuration, according to an embodiment.
[0021] FIG. 9 illustrates a top view of the tong with the jaws in a
first engaging position, according to an embodiment.
[0022] FIG. 10 illustrates a top view of the tong in a second
engaging position, according to an embodiment.
[0023] FIG. 11 illustrates a flowchart of a method for rotating a
tubular using a tong, according to an embodiment.
[0024] It should be noted that some details of the figure have been
simplified and are drawn to facilitate understanding of the
embodiments rather than to maintain strict structural accuracy,
detail, and scale.
DETAILED DESCRIPTION
[0025] Reference will now be made in detail to embodiments of the
present teachings, examples of which are illustrated in the
accompanying drawing. In the drawings, like reference numerals have
been used throughout to designate identical elements, where
convenient. In the following description, reference is made to the
accompanying drawing that forms a part thereof, and in which is
shown by way of illustration a specific exemplary embodiment in
which the present teachings may be practiced. The following
description is, therefore, merely exemplary.
[0026] In general, the present disclosure provides a tong for
rotating a tubular (e.g. a casing) and/or otherwise applying a
torque thereto. In some embodiments, the tong includes a worm drive
that has input power supplied by a motor (e.g., a hydraulic,
electric, or pneumatic motor). The worm drive may engage cam
followers attached to a rotary section of the tong. The rotary
section generally includes a cage plate assembly, a rotary ring,
and jaws. Input rotation of the worm drive may cause the screw
thereof to apply a linear force to the cam followers, which is
translated to a tangential force on the rotary section, causing the
rotary ring of the rotary section to rotate. Initially, the cage
plate assembly and the jaws are restrained from rotating, such that
rotation of the rotary ring causes jaws to move radially inwards
across a range of radial positions. When a tubular is received
through the tong, such rotation causes the jaws to engage the
tubular. Continued rotation of the rotary ring may, after such
engagement, cause cage plate and jaws to rotate along with the
rotary ring, and thereby rotate the tubular. The worm drive may be
reversed, which may reverse the rotation of the rotary ring and
cause the jaws to retract and move radially outward (e.g., into
pockets) so as to disengage from the tubular. The jaws may retract
far enough away from the tubular to allow passage of the tubular,
e.g., including the box end thereof, vertically through the tong.
These and other features will be described in greater detail below
with reference to several example embodiments.
[0027] Turning now to the illustrated embodiments, FIG. 1
illustrates a raised, perspective view of a tong 100, according to
an embodiment. The tong 100 may be a power tong, which may be
configured to rotate a tubular received therethrough. The tong 100
may include a rotatable section 102 and a stationary section 104.
The rotatable section 102 may be coupled to the stationary section
104 and may be driven to rotate with respect thereto. Further, the
rotatable section 102 may be annular and may include a receiving
hole 106 therethrough. As will be described in greater detail
below, the tong 100 may include jaws or any other type of engaging
structures that extend radially into the receiving hole 106 to grip
a tubular received therethrough.
[0028] In an embodiment, the rotatable section 102 may include a
top guard 108, which may be generally disk-shaped and may serve to
protect other tong 100 components from damage, e.g., if an elevator
or another object lands on the tong 100. The rotatable section 102
may also include a removable cover 110, which may be generally
L-shaped in cross section (e.g., extending vertically and then
horizontally to meet the top guard 108) and configured to cover an
access gap, as will be described in greater detail below. The cover
110 may, for example, be fastened to the top guard 108 via
bolts.
[0029] Further, the rotatable section 102 may include a guide 112,
which may be coupled with or disposed within the top guard 108. The
guide 112 may be annular and beveled or tapered, so as to receive
and direct an end of a tubular therethrough. The guide 112 may be
positioned in alignment with the receiving hole 106, and thus may
serve to guide the tubular into the receiving hole 106. Further,
the guide 112 may be provided in at least two pieces (e.g.,
segments 112A, 112B), which may be separately removable, e.g., to
allow for lateral removal of a tubular from within the receiving
hole 106.
[0030] The rotatable section 102 may also include a cage plate 114
and a rotary ring 118. For example, the cage plate 114 may be
disposed vertically below and adjacent to the top guard 108. The
rotary ring 118 may be below the cage plate 114 and may be seated
on the stationary section 104, and configured to rotate with
respect thereto. Further, the rotary ring 118 may initially be
rotatable relative to the cage plate 114.
[0031] The top guard 108 may include openings 119 extending
therethrough, and through which backing pins 117A, 117B are
received. As will be described in greater detail below, the backing
pins 117A, 117B may be held generally stationary with respect to
the cage plate 114 and the top guard 108 and may serve to provide
an end range for relative movement between the rotary ring 118 and
the cage plate 114.
[0032] The stationary section 104 may include a brake band 116 and
a body 120 to which the rotatable section 102, e.g., the rotary
ring 118, may be movably coupled. The brake band 116 may extend at
least partially around a circumference of the cage plate 114. The
body 120 may support the tong 100 and may be coupled to an external
structure, whether stationary (e.g., the rig floor) or mobile
(e.g., a lifting assembly, carriage, hoist, etc.). Further, the
body 120 may be coupled to a motor 122 via motor mounts 124. The
body 120 may also include an access door 126, which may be opened,
e.g., to allow lateral movement of a tubular therethrough.
[0033] The motor 122 may be energized to rotate the rotatable
section 102 relative to the stationary section 104. Such rotation
may result in a reactionary torque load being applied from the
rotatable section 102 to the body 120. The stationary section 104
may thus include a load cell 128 positioned between the motor mount
124 and the body 120, which may measure such torque. The measured
torque may provide information about the torque load applied by the
tong 100 onto a tubular connection, thereby indicating when the
connection is fully made. In an embodiment, the motor 122 may be a
hydraulic motor, but in other embodiments, other types of drive
systems may be employed, including electric motors and/or pneumatic
motors.
[0034] FIG. 2A illustrates another perspective view of the tong
100, according to an embodiment. In this view, the body 120 (FIG.
1) is omitted for purposes of illustration. The tong 100 includes a
shield plate 200, which is partially shown as transparent to allow
illustration of the internal components of the drive system for the
tong 100. As shown, the motor 122 may be configured to drive a
shaft 202 that includes a helical ridge or "tooth" 204, e.g.,
forming a worm drive.
[0035] The rotatable section 102 may include cam followers 206,
which may extend downward therefrom, as shown, for example. The cam
followers 206 may, in some embodiments, be cylindrical and may or
may not include bearing elements between the outer roller and inner
shaft of the cam follower. The cam followers 206 may be disposed in
a circular pattern near or along the radially outer periphery of
the rotatable section 102. In particular, the cam followers 206 may
extend downward from the rotary ring 118, and may be coupled
thereto such that forces incident on the cam followers 206 are
transmitted to the rotary ring 118.
[0036] The helical ridge 204 may engage the cam followers 206.
Accordingly, the helical ridge 204 may be positioned at least
partially axially below the rotary ring 118, such that the helical
ridge 204 and the shaft 202 radially overlap the stationary section
104 and the rotatable section 102 (e.g., as seen in a top view of
the tong 100), which may provide for a compact footprint of the
tong 100. Further, the shaft 202 and the helical ridge 204 may be
oriented in a generally tangential direction to the rotary ring
118. As the helical ridge 204 turns, it may engage and apply a
linear force on the cam followers 206. The cam followers 206 may
transmit this force to the rotary ring 118 as a tangential force
applied thereto. This in turn results in a torque force on the
rotary ring 118, causing the rotary ring 118 to rotate about the
receiving hole 106.
[0037] In some embodiments, the cam followers 206 and the helical
ridge 204 may be sized and configured such that at least one, at
least two, or more cam followers 206 engage the helical ridge 204
at any given point during rotation, e.g., when one cam follower 206
rotates out of the helical ridge 204, another enters into it. This
may maintain a smooth rotation of the rotary ring 118 when the
helical ridge 204 is turned by the motor 122. The tong 100 may also
include a speed reducer and encoder 208, which may measure a speed
and/or an angular position of the shaft 202.
[0038] FIG. 2B illustrates a simplified, bottom view of the tong
100, illustrating another embodiment. As shown, the cam followers
206 extend from the rotary ring 118, e.g., to a location axially
below the rotary ring 118. The motor 122 is also present, and is
operable to drive a pair of helical ridges 250, 252 via two shafts
254, 256, respectively. The shafts 254, 256 may be connected
together via a gear box 258, which may allow the shafts 254, 256 to
be rotated by a single motor 122, while being disposed at an angle
relative to one another (e.g., about 90 degrees, as shown).
Accordingly, the shafts 254, 256 and the helical ridges 250, 252
may both extend tangentially to the rotary ring 118, such that the
helical ridges 250, 252 engage the cam followers 206, thereby
applying a tangentially-directed force on the rotary ring 118,
causing the rotary ring 118 to rotate.
[0039] It will be appreciated that three or more helical ridges
250, 252 may be employed, with the embodiments above describing one
helical ridge and two helical ridges being merely examples.
Further, a variety of arrangements for driving the shafts 254, 256
in multi-shaft embodiments are contemplated (e.g., both shafts 254,
256 and the motor 122 could be connected to the gear box 258 such
that the gear box 258 is between the motor 122 and the shafts 254,
256) and may be used within the scope of the present
disclosure.
[0040] FIG. 3 illustrates a raised perspective view of the tong 100
with the top guard 108 and cover 110 removed for purposes of
illustration, according to an embodiment. The cover 110 (e.g., FIG.
1) covers an access gap 300, which may be formed in the cage plate
114. A removable portion 304 of the rotary ring 118 may extend
through the access gap 300. The removable portion 304 of the rotary
ring 118 may be hinged or detachable, e.g., along with the cover
110 (FIG. 1) and at least one segment 112B of the guide 112 (FIG.
1), so as to allow lateral entry or exit of a tubular into the
receiving hole 106.
[0041] In addition, FIG. 3 illustrates the tops of the cam
followers 206 extending through the rotary ring 118. The cam
followers 206 may be received through bores formed in the rotary
ring 118. Further, the tops of the cam followers 206 may extend
into a passage 302 formed in the cage plate 114, thereby allowing
the cam followers 206 to move, along with the rotary ring 118,
circumferentially with respect to the cage plate 114. The cam
followers 206 may also extend downward, through the rotary ring 118
and below the body 120, so as to engage the helical ridge 204, as
shown in and described above with reference to FIG. 2A. The cam
followers 206 may include first rollers 610 below the rotary ring
118, which may be configured to engage the helical ridge 204 (FIG.
2) below the rotary ring 118. The cam followers 206 may also
include second rollers 612 above and seated on the rotary ring 118,
such that the cam followers 206 are free to rotate within the bore
with respect to the rotary ring 118. The cam followers 206 may also
each include a first shaft 614A and a second shaft 614B. The first
roller 610 may be positioned around the first shaft 614A, and the
second roller 612 may be positioned around the second shaft 614B.
The first and second shafts 614A, 614B may be connected together.
In some embodiments, a single shaft or three or more shafts may be
employed.
[0042] FIG. 4 illustrates a raised perspective view of the tong 100
with the top guard 108 and the cage plate 114 removed for purposes
of illustration, according to an embodiment. FIG. 5 illustrates a
top view of the tong 100, also with the top guard 108 and the cage
plate 114 removed for purposes of illustration, according to an
embodiment. Referring to both FIGS. 4 and 5, the tong 100 may
include a plurality of engaging members or "jaws" (three shown:
400A, 400B, 400C), which may be movable radially (i.e., toward and
away from a center of the receiving hole 106) to grip a tubular.
The jaws 400A-C may include teeth, wickers, buttons, grit,
high-friction surfaces, or any other structure configured to grip a
tubular and transmit a high radial and torque load to the tubular.
For example, the jaws 400A-C may include replaceable inserts or
"dies" providing such marking structures, which may be readily
replaceable. The jaws 400A-C may be coupled with the cage plate
114, as will be described in greater detail below, and may be
configured to slide radially, between a retracted position and an
engaging position, with respect thereto.
[0043] The brake band 116 may be tight around the cage plate 114,
thereby generating friction that prevents the cage plate 114 from
rotating relative to the brake band 116, at least initially. In
turn, the brake band 116 may be coupled with the body 120 via one
or more posts 401 (two are shown), which may prevent the brake band
116 from rotating relative to the body 120. The brake band 116 may
be pulled tight between the posts 401 so as to provide the friction
on the cage plate 114. In other embodiments, other types of braking
structures that initially allow the rotary ring 118 to rotate
relative to the cage plate 114 may be employed.
[0044] The jaws 400A-C are illustrated in the retracted position.
In particular, in this embodiment, the rotary ring 118 includes an
inner profile 402 in which one or more pockets (three are shown:
404A, 404B, 404C) are defined, for example, one for each of the
jaws 400A-C, although additional pockets could also be provided.
The pockets 404A-C may extend radially outward from the inner
profile 402, providing a space into which the jaws 400A-C may be
retracted and held away from the tubular received through the
receiving hole 106. Thus, the pockets 404A-C may allow the jaws
400A-C to retract, which may allow the tong 100 to slide over
tubular connections, upsets, couplings, etc. The inner profile 402
may also include one or more cam surfaces (three shown: 406A, 406B,
406C), which may be arcuate segments that have a radius of
curvature that is less than the overall inner profile 402, or may
otherwise tend to extend radially inwards as proceeding in a
circumferential direction around the inner profile 402 of the
rotary ring 118. Each of the cam surfaces 406A-C may define an apex
409, where the inner profile 402 may transition from extending
radially inward to extending radially outward. The cam surfaces
406A-C provide an extended range of radial dimensions for tubulars
that may be gripped using the jaws 406A-C.
[0045] The rotary ring 118 may define backing slots 408A, 408B that
receive the respective backing pins 117A, 117B therein. As noted
above, the backing pins 117A, 117B may be stationary with respect
to the cage plate 114, and thus, initially, the rotary ring 118 may
rotate relative to the backing pins 117A, 117B. Accordingly, the
backing pins 117A, 117B may move within the slots 408A, 408B as the
rotary ring 118 rotates relative to the cage plate 114, until the
backing pins 117A, 117B engage an end of the respective slots 408A,
408B or the rotary ring 118 is otherwise prevented from continued
rotation relative to the cage plate 114 (e.g., by the jaws 400A-C
engaging a tubular). Thus, the slots 408A, 408B may be arcuate to
accommodate such circumferential movement, and may extend roughly
along the maximum range of relative rotation to be allowed between
the rotary ring 118 and the jaws 400A-C. It will be appreciated
that the illustrated embodiment including two backing slots 408A,
408B and two backing pins 117A, 117B, is merely one example, and
any number of slots and/or backing pins may be employed.
[0046] Further, the tong 100 may include one or more return springs
410, e.g., two for each of the jaws 400A-C, as shown. Each of the
return springs 410 may extend between posts 412, 414, with the post
414 being stationary with respect to and attached to the cage plate
114 (not visible), and the posts 412 being radially movable along
with the jaws 400A-C, as will be described in greater detail below.
Accordingly, the spring 410 may bias the jaws 400A-C radially
outwards, so as to pull the jaws 400A-C back into the pockets
400A-C when they are circumferentially aligned therewith. The
return springs 410 may be connected to pins 412, 414. In turn, the
pins 412 may be connected to the jaws 400A-C and the pins 414 may
be connected to the cage plate 414.
[0047] FIG. 6A illustrates a top, perspective view of the cage
plate 114 of the tong 100, according to an embodiment. As shown,
the cage plate 114 may include a plurality of pinholes (four are
shown: 601A, 601B, 601C, 601D). The pinholes 601A, 601B may be
aligned with the first backing slot 408A of the rotary ring 118
(see, e.g., FIGS. 4 and 5), and the pinholes 601C, 601D may be
aligned with the second backing slot 408B of the rotary ring 118.
Accordingly, the backing pin 117A may extend through either of the
pinholes 601A, 601B and be received into the first backing slot
408A, and/or the backing pin 117B may extend through either of the
pinholes 601C, 601D and into the second backing slot 408B. The
pinholes 601A-D may also be aligned with respective openings 119 in
the top guard 108 (FIG. 1).
[0048] The pinholes 601B, 601D may correspond to a make-up or
"make" position (as indicated), which, when a backing pin 117A,
117B is received therethrough and into the corresponding slot 408A,
408B, may allow for a range of rotation of the rotary ring 118 in a
first circumferential direction, while initially preventing
rotation in a second, opposite circumferential direction. The
pinholes 601A, 601C may correspond to a break out or "break"
position, which, when a backing pin 117A, 117B is received
therethrough, may allow rotation of the rotary ring 118 relative to
the cage plate 114 in the second circumferential direction, while
initially preventing rotation in the first direction. As noted
above, the backing pins 117A, 117B may be removable through the top
guard 108 via the openings 119, and thus the direction of rotation
allowed by the backing pins 117A, 117B may be readily reversed by
removing the backing pins 117A, 117B and putting them in the
pinhole that allows the desired rotation. In some embodiments, two
backing pins 117A, 117B may be provided, each going through one of
the make pinholes 601B, 601D (as shown), or through one of the
break pinholes 601A, 601C. In other embodiments, any other number
of backing pins, pinholes, and/or backing slots may be
employed.
[0049] Further, radially-extending spring slots 603 may be
provided, which may receive the posts 412 by which the springs 410
are attached to the jaws 400A-C. The posts 414 may be fixed in
position relative to the cage plate 114, as noted above, while the
posts 412 may be movable radially in the spring slots 603 as the
jaws 400A-C move radially.
[0050] FIG. 6B illustrates another perspective view of the cage
plate 114 of the tong 100, according to an embodiment. As can be
seen by comparison with the view of FIG. 6A, the jaws 400A-C have
moved radially inward. As such, the posts 412 have moved
correspondingly in the slots 603, and the spring 410 has been
extended. As will be described in greater detail below, this
radially-inward movement of the jaws 400A-C may be caused by
relative rotation between the rotary ring 110 and the cage plate
114. Further, the jaws 400A-C may be permitted to move radially
with respect to the cage plate 114, but may be prevented from
circumferential movement (i.e., rotation about the centerline of
the tong 100) prevented from rotating relative to the cage plate
114.
[0051] With continuing reference to FIGS. 6A and 6B, FIG. 6C
illustrates a vertical cross-sectional view of the tong 100,
according to an embodiment. The view provides an illustration of
the linkage between the cam followers 206 and the rotary ring 118,
among other things. As shown, the cam followers 206 may extend
axially through the body 120, where they may rotate into and out of
engagement with the helical ridge 204 of the worm drive.
[0052] The cam followers 206 may also extend at least partially
(e.g., entirely) through the rotary ring 118, and upwards into the
passage 302 in the cage plate 114. Accordingly, force in the
horizontal plane on the cam followers 206 may be transmitted to the
rotary ring 118 through the cam followers 206. In particular, the
helical ridge 204 may impart a linear force on the cam followers
206, which in turn generates a tangential force on the rotary ring
118, thereby causing the rotary ring 118 to rotate.
[0053] As mentioned above, and also viewable in FIG. 6A, the jaws
400A-C (jaws 400A and 400C are visible in FIG. 6B) may be coupled
with the cage plate 114 such that they are movable radially, along
a generally linear path, with respect thereto, but may be prevented
from rotating (travelling in a circumferential direction) with
respect to the cage plate 114. For example, the cage plate 114 may
include T-slots 600, which may be radially oriented. Each one of
the jaws 400A-C may fit in a separate T-slot 600, thereby allowing
such radial motion but preventing movement in the circumferential
direction relative to the cage plate 114.
[0054] In the embodiment illustrated in FIGS. 4 and 5, the jaws
400A-C slide along the rotary ring 118 as the rotary ring 118
rotates. In the embodiment of FIG. 6, the jaws 400A-C are
additionally provided with rollers 602, which may roll along the
rotary ring 118, e.g., the pockets 404A-C (see FIG. 4) and cam
surfaces 406A-C (see FIG. 4), so as to reduce friction in such
movement. The inclusion of such rollers may be optional in any of
the embodiments discussed herein.
[0055] FIG. 7 illustrates a partial, schematic view of another
embodiment of the rotary ring 118, according to an embodiment. The
pocket 404A and cam surface 406A are illustrated, but may be
representative of the remaining pockets and cam surfaces, as shown,
e.g., in FIG. 5. As illustrated in FIG. 7, the cam surface 406A may
have a stepped profile, including a first surface 700 and a second
surface 702. The first surface 700 may extend at a generally
uniform radius across an arc of a certain angle, until reaching a
transition surface or "ramp" 704. The transition surface 704 may
extend generally linearly, or at a different radius of curvature
than the first surface 700, and may extend to the second surface
702. The second surface 702 may thus begin at a position that is
radially offset from where the first surface 700 met with the
transition surface 704. The second surface 702 may then extend from
the transition surface 704 at the same or a different radius of
curvature than the first surface 700.
[0056] Accordingly, in operation, one of the jaws (e.g., the jaw
400A) may initially sit in the pocket 404A, but may be pushed out
of the pocket 404A by the clockwise rotation of the rotary ring
118, as the jaw 400A is held stationary by the cage plate 114. The
jaw 400A may thus ride up onto the first surface 700 of the cam
surface 406C, until reaching the transition surface 704. The
transition surface 704 may abruptly push the jaw 400A radially
inward, and then onto the second surface 702. The jaw 400A may then
continue to move radially inward as the rotary ring 118 continues
to rotate. This stepped profile for the cam surface 406A may be
capable of further extending the range of diameters of tubulars
that may be effectively gripped by the tong 100.
[0057] Referring now to FIGS. 8-10, an example of operation of the
tong 100 is shown. In such operation, the rotary ring 118 may be
driven to rotate relative to the body 120 by the motor 122 and the
linkage provided by the cam followers 206. The jaws 400A-C may be
coupled with the cage plate 114 such that they are non-rotational
with respect thereto, but radially slidable relative to the cage
plate 114. The cage plate 114 may be initially secured against
rotation by friction force applied by the brake band 116. Thus, as
the rotary ring 118 begins to rotate relative to the body 120, the
rotary ring 118 may also rotate relative to the cage plate 114 and
the jaws 400A-C. By such rotation, the jaws 400A-C may be forced
out of the pockets 404A-C and circumferentially, as well as
radially inward, onto the cam surfaces 406A-C. Continued rotation
of the rotary ring 118 relative to the jaws 400A-C may cause the
jaws 400A-C to move farther radially inward until reaching an
engaging position, where the jaws 400A-C are designed to engage a
tubular received in the receiving hole 106. In embodiments in which
the backing pins 117A, 117B and slots 408A, 408B are provided, if
the jaws 400A-C do not engage a tubular after a maximum amount of
rotation, the backing pins 117A, 117B may engage an end of the
respective slots 408A, 408B to prevent continued relative rotation
by overcoming the holding force applied by the brake band 116 (see,
e.g., FIG. 1) on the cage plate 114. When this occurs, the cage
plate 114 may rotate with the rotary ring 118. The maximum range of
rotational movement allowed by the backing pins 117A, 117B in the
backing slots 408A, 408B may correspond to where the jaws 400A-C
reach the apex 409 of each of the cam surfaces 406A-C (see FIG.
4).
[0058] When the jaws 400A-C engage a tubular, such as tubular 900,
shown in FIG. 9, a force between the jaws 400A-C and the cam
surfaces 406A-C may increase, as the cam surfaces 406A-C wedge the
jaws 400A-C tighter against the tubular 900. This may overcome the
holding force applied on the cage plate 114 by the brake band 116.
Thus, as the rotary ring 118 continues to rotate, the jaws 400A-C
and the cage plate 114 may also rotate. Further, this may also
cause the tubular 900 engaged by the jaws 400A-C to rotate with
respect to the body 120.
[0059] The tong 100 may also be configured to engage a second
tubular 1000, as shown in FIG. 10. The second tubular 1000 may have
a smaller diameter than the first tubular 900, and thus further
extension of the jaws 400A-C may be called for to accomplish such
engagement. Thus, the rotary ring 118 rotation is allowed to rotate
farther in the first direction, such that the jaws 400A-C continue
to ride along the cam surfaces 406A-C until extending far enough
inwards to engage the tubular 1000. As such, tubulars of different
diameters may be engaged by the tong 100, without reconfiguration
of the tong 100 itself; the rotary ring 118 simply rotates until
the jaws 400A-C engage the tubular, regardless of the tubular size,
within a design range.
[0060] In either example case (FIG. 9 or 10), when release of the
tubular 900 or 1000 is desired, the rotation of the rotary ring 118
may reverse. Upon reverse rotation of the rotary ring 118, the
return springs 410 may hold the jaws 400A-C radially outwards
against the cam surfaces 406A-C and eventually force the jaws
400A-C back into the pockets 404A-C. The pockets 404A-C may thus
allow the jaws 400A-C to retract, which may allow the tong 100 to
remain received around a tubular while sliding over a collar,
centralizer, tool, or connection between two pipes, as will be
described in greater detail below.
[0061] Embodiments of the disclosure may also include a method for
operating such tongs. FIG. 11 illustrates a method 1100 for
rotating a tubular using a tong, according to an embodiment. The
method 1100 is described herein with reference to the tong 100,
according to the various embodiments of FIGS. 1-10, but it will be
appreciated that other embodiments of the method 1100 may employ
other types of tongs, and thus the method should not be considered
limited to any particular structure unless otherwise stated.
[0062] The method 1100 may include positioning a tubular within the
receiving hole 106 of the tong 100, as at 1102. This may be
accomplished, e.g., by vertically translating the tubular through
the top of the receiving hole 106, moving the tong 100 upwards (as
with a lifting assembly), or by receiving the tubular laterally
through the access door 126, with the cover 110 and at least a
segment 112B of the guide 112 removed, as well as the access door
126 (with the portion 304 of the cage plate 114 and/or rotary ring
118) removed or swung open.
[0063] The method 1100 may then proceed to engaging the tubular
using jaws 400A-C of the tong 100 by activating the motor 122 of
the worm drive, which causes the helical ridge 204 to rotate in a
first direction, as at 1104. Rotation of the helical ridge 204
applies a tangential force on the rotary ring 118 via engagement
with the cam followers 206, resulting in the rotary ring 118
rotating in a first circumferential direction. The rotation of the
rotary ring 118 in the first circumferential direction causes the
jaws 400A-C to move out of the pockets 404A-C and onto the cam
surfaces 406A-C as described above. Eventually, the rotation of the
rotary ring 118 relative to the cage plate 114 is stopped, either
by the jaws 400A-C engaging the tubular or the backing pin(s) 117A
and/or 117B engaging an end of the respective slots 408A, 408B,
thereby overcoming the resistance to rotation that the brake band
116 applies on the cage plate 114. With the jaws 400A-C engaged
with the tubular, and the motor 122 remaining active, the tong 100
may apply a torque to the tubular, causing the tubular to rotate,
as at 1106. In turn, threads of the tubular may be advanced into
engagement with mating threads of another tubular (e.g., a box-end
of a stump).
[0064] The method 1100 may then include disengaging the jaws 400A-C
of the tong 100 from the tubular, as at 1108, by stopping and
reversing the direction of the rotation of the helical ridge 204,
e.g., by activating the motor 122 to rotate in a second, reverse
direction. The jaws 400A-C may slide back along the cam surfaces
406A-C, and, as they are biased radially outward by the springs
410, may eventually slide back into the respective pockets
404A-C.
[0065] With the jaws 400A-C retracted, the tubular may move,
relative to the tong 100, such that, for example, an expanded,
box-end of the tubular may move through the tong 100, as at 1110.
This may occur before or after rotating the tubular using the tong
100. In some embodiments, the tubular may be laterally removed from
the tong 100, as described above. The method 1100 may also include
engaging and rotating a second tubular of a second diameter that is
different from the diameter of the first tubular, again using the
tong, and without reconfiguring the tong 100, as at 1112.
[0066] While the present teachings have been illustrated with
respect to one or more implementations, alterations and/or
modifications may be made to the illustrated examples without
departing from the spirit and scope of the appended claims. In
addition, while a particular feature of the present teachings may
have been disclosed with respect to only one of several
implementations, such feature may be combined with one or more
other features of the other implementations as may be desired and
advantageous for any given or particular function. Furthermore, to
the extent that the terms "including," "includes," "having," "has,"
"with," or variants thereof are used in either the detailed
description and the claims, such terms are intended to be inclusive
in a manner similar to the term "comprising." Further, in the
discussion and claims herein, the term "about" indicates that the
value listed may be somewhat altered, as long as the alteration
does not result in nonconformance of the process or structure to
the illustrated embodiment. Finally, "exemplary" indicates the
description is used as an example, rather than implying that it is
an ideal.
[0067] Other embodiments of the present teachings will be apparent
to those skilled in the art from consideration of the specification
and practice of the present teachings disclosed herein. It is
intended that the specification and examples be considered as
exemplary only, with a true scope and spirit of the present
teachings being indicated by the following claims.
* * * * *