Note: Descriptions are shown in the official language in which they were submitted.
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Oilfield Elevator
Field
The invention relates to an oilfield pipe elevator.
Background
An elevator is a hinged mechanism with two segments that may be closed around
tubulars such as drillpipe, casing or other drillstring components to
facilitate moving
them into and out of the wellbore and about the rig. When the elevator
segments are in
the closed position, the elevator segments are latched together to form a load-
bearing
ring, which may be positioned around the component. A shoulder or taper on the
component to be lifted is larger in size than the inside diameter of the
closed elevator.
In the open position, the elevator segments may be rotated about their hinged
connection to swing away from the tubular.
A manual elevator requires a person to drive the segments about the hinge to
open or
close the elevator and may require a person to actuate a latch and possibly a
lock
between the segments.
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Summary
In accordance with a broad aspect of the present invention, there is provided
an oilfield
elevator comprising: a first body segment including a first end and an
outboard end; a
second body segment including a first end and an outboard end, the first body
segment
being pivotally connected through a hinge at its first end to the first end of
the second
body segment and the first and second body segments being releasably
connectable at
their outboard ends to form a pipe-receiving opening therebetween; a locking
mechanism operable by axial movement of the first body segment relative to the
second
body segment to control pivotal rotation about the hinge; and an actuation
lever
positioned between the first body segment and the second body segment, the
actuation
lever including a protrusion thereon and being moveable to drive the
protrusion against
the first body segment to drive the first body segment axially relative to the
second body
segment.
In accordance with a broad aspect of the present invention, there is provided
an oilfield
elevator comprising: a first body segment including a first end, a barrel at
the first end
and an outboard end, the barrel including a cam surface; a second body segment
including a first end, lugs at the first end and an outboard end, a hinge
formed by the
pivotal connection of the barrel, lugs and a hinge pin; wherein the first and
second body
segments are releasably corinectable at their outboard ends to form a pipe-
receiving
opening therebetween; an actuation lever positioned at the hinge between the
barrel
and lugs, the actuation lever including a cam surface; and a power cylinder
connected
at one end to the actuation lever and at another end to a connection on the
second
body segment; wherein the actuation lever and power cylinder move
cooperatively in a
planar direction to move the first and second body segments axially by
interaction
between the actuation lever cam surface and the barrel cam surface.
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In accordance with a broad aspect of the present invention, there is provided
a method
for operating a pipe elevator comprising: (a) providing a pipe elevator
including: a first
body segment with a first end and an outboard end, a second body segment with
a first
end and an outboard end, the first body segment being pivotally connected
through a
hinge at its first end to the first end of the second body segment, wherein
the first and
second body segments are releasably connectable at their outboard ends to form
a
pipe-receiving opening therebetween, a locking mechanism operable to be locked
and
unlocked by axial movement of the first body segment relative to the second
body
segment to control pivotal rotation about the hinge; and (b) moving the first
body
segment axially relative to the second body segment to release the locking
mechanism
before any rotational movement of the first body segment and the second body
segment
is initiated about the hinge.
In accordance with a broad aspect of the present invention, there is provided
an oilfield
elevator comprising: a first body segment including a first end and an
outboard end; a
second body segment including a first end and an outboard end, the first body
segment
being pivotally connected through a hinge at its first end to the first end of
the second
body segment and the first and second body segments being releasably
connectable at
their outboard ends to forrn a pipe-receiving opening therebetween; and a
locking
mechanism operable by axial movement of the first body segment relative to the
second
body segment to control pivotal rotation about the hinge.
It is to be understood that other aspects of the present invention will become
readily
apparent to those skilled in the art from the following detailed description,
wherein
various embodiments of the invention are shown and described by way of
illustration.
As will be realized, the invention is capable for other and different
embodiments and its
several details are capable of modification in various other respects, all
without
departing from the spirit and scope of the present invention. Accordingly the
drawings
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and detailed description are to be regarded as illustrative in nature and not
as
restrictive.
Brief Description of the Drawings
Referring to the drawings, several aspects of the present invention are
illustrated by
way of example, and not by way of limitation, in detail in the figures,
wherein:
Figure 1 a is a top plan view of a prior art automated single joint elevator
in an open
position;
Figure lb is a top plan view of the prior art automated single joint elevator
of Figure la
in the closed position;
Figure 2a is a top perspective view of one embodiment of a single joint
elevator
according to the present invention with the segments in the closed position;
Figure 2b is a front elevation of the elevator of Figure 2a in the closed
position;
Figure 2c is a top plan view of the elevator of Figure 2a in the closed
position;
Figure 2d is a top plan view of the elevator of Figure 2a in the open
position;
Figure 3a is an enlarged view from the front of the hinge portion of the
elevator of Figure
2d;
Figure 3b is an enlarged view from the rear of the hinge portion of the
elevator of Figure
2a;
Figure 3c is an enlarged perspective view of an actuation lever useful in one
embodiment of an automatecl elevator;
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Figure 3d is an enlarged perspective view of a hinge end portion of a segment
useful in
one embodiment of an automated elevator; and
Figure 3e is an enlarged cutaway view from the rear of the hinge portion of
the elevator
of Figure 2a.
Detailed Description of Various Embodiments
The detailed description set forth below in connection with the appended
drawings is
intended as a description of various embodiments of the present invention and
is not
intended to represent the only embodiments contemplated by the inventor. The
detailed
description includes specific details for the purpose of providing a
comprehensive
understanding of the present invention. However, it will be apparent to those
skilled in
the art that the present invention may be practiced without these specific
details.
Figures 1 a and lb show a prior art automated elevator. An elevator includes a
first
segment 10 and a second segment 12 connected by a hinge 14. Each segment has a
hinged end and an outboard end. In operation, an elevator is moveable between
an
open position, shown in Figure 1 a, and a closed position, shown in Figure lb.
Each
segment includes an inner edge 16a, 16b formed as at least a portion of a
circle such
that when the outboard ends are brought together in the closed position, the
segments
together form a generally circular opening that may be placed about a tubular
to be
handled thereby.
In the open position, a tubular may be inserted through the opening between
the
outboard ends of the segments opposite hinge 14 and once the tubular is in
position,
segments 10, 12 may be closed about the tubular. By selection of the segment
size
and/or parts forming the inner edges 16a, 16b, an upset portion of the tubular
will catch
on the inner edges 16a, 16b such that the tubular cannot pass out from the
elevator
once the segments are secured, as by use of a latch 18, about the tubular.
Latch 18, in
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this embodiment, includes catch plate 28, which includes an extension 28a that
may be
engaged behind a stop 30 on second segment 12 to secure the segments together.
An elevator as shown, may be automated to open and close by including a link
arrangement and a driver. For example, an automated elevator may include a
cylinder
20 pivotally connected between first segment 10 and second segment 12 and set
up to
drive rotation about hinge 14. In one embodiment, the cylinder may be
pivotally
connected between a bracket 22 on one of the segments and a bracket 24 on the
other
of the segments such that extension and retraction of the cylinder drives the
segments
to rotate about the hinge.
Bracket 24 is also pivotally connected to its segment, in this case elevator
segment 10,
such that retraction of the cylinder also causes bracket 24 to pivot about its
pivotal
connection 25 to segment 10., A link rod 26 is pivotally connected to bracket
24 to move
therewith. Link rod 26 is connected at its opposite end 26a to catch plate 28
of latch 18.
Link rod 26 is connected to catch plate 28 and configured to drive the catch
plate about
a fulcrum 32 to move the extension into and out of engagement with stop 30.
In operation to close the elevator segments (to go from the position of Figure
1 a to that
of Figure 1 b), for example, cylinder 20 may be extended to drive the segments
such that
their outboard ends come together about hinge 14. This movement of cylinder 20
drives bracket 24 toward link rod 26 and link rod 26 drives catch about its
fulcrum 32 to
move extension 28a behind stop 30. A spring 33 may be positioned about fulcrum
32 to
bias catch 28 into a latched position with stop 30.
With reference to Figures 2 and 3 an automated elevator has been proposed
which
provides an alternate mechariism over a prior art elevator as shown in Figure
1 a. In the
illustrated embodiment, the eNevator includes a first segment 110 and a second
segment
112 connected by a hinge 114. Each segment includes a hinged end and an
outboard
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end 110a, 112a. In operation, this elevator is moveable between a closed
position,
shown in Figures 2a to 2c and an open position, shown in Figure 2d. Hinge 114
includes a hinge pin 123 that defines an axis x about which the segments may
rotate to
open and close. To define the hinge, portions of the segments may be mounted
to
rotate on the hinge pin. For example, lugs 134 of one segment may be fixed or
pivotally
mounted on either end of the hinge pin and a barrel 138 of the other segment
may
pivotally ride on hinge pin between lugs 134. Each segment includes an inner
curved
edge 11 6a, 11 6b formed as at least a portion of a circle such that when the
outboard
ends are brought together in the closed position, the segments form a
generally circular
pipe-receiving opening therebetween that may be placed about a tubular to be
handled
thereby.
In the open position, a tubular may be inserted through the opening between
the
outboard ends of the segments opposite hinge 114. Once the tubular is in
position,
segments 110, 112 may be closed about the tubular. By selection of the segment
sizes
and/or parts forming the inner edges 116a, 116b, an upset portion of the
tubular will
catch on the inner edges and cannot pass out from the elevator once the
segments are
secured, as by use of one or more locking mechanisms, about the tubular.
An elevator as shown, may be automated to open and close by an automation
system
that acts about the hinge to both actuate the locking mechanisms and to rotate
the
segments. Although the elevator may include a locking mechanism between the
outboard ends opposite the hinge, a mechanism acting about the hinge may
control the
actuation of that locking mechanism. In such an embodiment, therefore the
installation
of actuators including cylinders, brackets, links, moveable latches or other
parts about
the opening side of the elevator, opposite the hinge, may be avoided.
In the illustrated embodiment, the automation system includes a driver and an
actuation
lever including a locking mechanism actuator and a segment drive mechanism to
cause
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rotation of the segments hinge. In the illustrated embodiment the driver
includes a
cylinder 120 mounted, through a fixed connection or, as shown, a pivotal
connection
121, at one end to one of the segments, which in this embodiment is second
segment
112. At the opposite end, cylinder 120 is mounted by a pivotal connection to
an
actuation lever 122. Of course, various drivers could be used such as screw
drives,
pneumatic or hydraulic cylinders, etc.
The actuation lever is installed to rotate about hinge pin 123 of hinge 114,
as shown by
arrow B. Hinge in the illustrated embodiment, lever 122 includes a pair of
spaced apart
bearings 122a including apertures through which the hinge pin extends when the
lever
is mounted to hinge pin 123 and an input extension 122b including two plates
including
apertures 122c or other means through which the lever is pivotally connected
to cylinder
120.
Actuation lever 122 may be formed to actuate at least one locking mechanism
acting
between the segments and/or to engage one of the segments to cause rotation of
that
segment relative to the other segment around the hinge.
One or more locking mechanisms may be provided to secure the segments together
when in the closed position. In the illustrated embodiment, the elevator
includes two
locking mechanisms actuated by axial displacement of the segments relative to
each
other. However, it is to be understood that one, or more of these or other
various
locking mechanisms may be used as desired.
A locking mechanism may be provided between outboard ends 110a, 112a of the
segments. The locking mechanism may include an interlocking feature that
operates to
prevent rotation of the segments about hinge 114 when the segments are
operating in
the same plane. However, such an interlocking locking mechanism may be
disengaged
by axial displacement of one segment relative to the other. In the illustrated
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embodiment, for example, corresponding hooks 130a, 130b are provided on facing
portions of ends 110a, 11 2a. Hooks 130a, 130b are formed to permit the
segments to
be rotated relative to each other when one segment 110 is raised (i.e. axially
offset)
relative to the other segment 112 (Figure 2d), but hooks 130 are formed to
interengage
when the hooks are axially aligned and the raised segment is set down to
assume a
position with its upper surface substantially in the same plane as the upper
surface of
the other segment (Figures 2a to 2b). When the segments are locked together by
hooks 130a, 130b, the segments cannot be rotated about hinge 114. However, if
it is
desired to open the elevator segments, one segment, for example segment 110,
must
be lifted along arrow A to move the hooks out of engagement so that the
segments can
be pulled apart. Although two sets of hooks are shown in the illustrated
embodiment, it
will be appreciated that one or more pairs of hooks may operate to secure the
parts
together. However, it is noted that where multiple sets of hooks are used,
sufficient
space must be provided axially therebetween to permit the corresponding hook
pairs to
be interposed into axial aligriment. To operate a locking mechanism including
hooks
130a, 130b, as shown, an actuator must be provided to raise one segment
relative to
the other.
Another locking mechanism rnay alternately or in addition be positioned
adjacent hinge
114 to control rotation about the hinge. The locking mechanism may include an
abutment 132 that operates to stop rotation of the segments about hinge 114
when the
segments are operating in the same plane but which may be avoided by axial
displacement of one segment relative to the other. In the illustrated
embodiment, for
example, abutment 132 is fixed in a position relative to hinge pin 123, in
this
embodiment on lug 134 extending from the second segment 112. Abutment 132 is
positioned to butt against a portion of segment 110, such as shoulder 135 to
stop
rotation of the first segment about the hinge. However, stopping against
abutment 132
may be avoided by raising segment 110 up along hinge pin 123, arrow C, until
shoulder
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135 of segment 110 is moved clear of the abutment. To operate a locking
mechanism
including an abutment at hinge 114, as shown, an actuator must be provided to
raise
one of the segments relative to the other.
In the illustrated embodiment, actuation lever 122 provides a lock mechanism
actuator
that raises segment 110 relative to segment 112. With reference to Figures 3,
for
example, actuation lever 122 is positioned with at least one of its bearings
122a acting
between the segments 110, 112. In particular, the lower most bearing of the
lever rides
between lower lug 134 and barrel 138 and includes a protrusion 136 on a
surface
positioned in contact with and below hinge barrel 138 of segment 110.
Protrusion 136
acts with and is formed to fit into a corresponding detent 140 in the lower
surface of
barrel 138 and can be moved into or out of the detent to raise and lower
segment 110.
As such, the protrusion can cause a camming action where it can be driven to
wedge
between the segments and force them apart (i.e lift the first segment away
against
gravity away from the second segment). In particular, protrusion 136 is formed
on the
lower bearing 122a of the actuation lever and detent 140 is formed on the
barrel in
relative positions so that when the actuation lever and segments 110 and 112
are in the
elevator closed position, the protrusion is positioned in detent 140
permitting barrel 138
to be in a lowermost position on hinge pin 123. When the elevator is in the
closed
position and actuation lever 122 initially rotates about hinge pin 123, the
locking
mechanisms which are engaged prevent rotation of segment 110 and so rotation
of the
lever causes protrusion 136 on lever 122 to move out of detent 140 and
protrusion 136
drives barrel 138 to slide upwardly along hinge pin 123. This raises segment
110
relative to segment 112. To facilitate the movement of protrusion 136 out of
detent
140a, the side edges 136a, 140a of one or both of the protrusion and the
detent can be
ramped.
It will be appreciated that once the segments are axially displaced to
disengage the one
or more locking mechanisms, the segments can be pivoted open about hinge. This
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opening movement could be achieved in various ways for example manually, by
drivers,
etc. However, in the illustrated embodiment, actuation lever 122 further
provides an
automation system for driving opening and closing of the segments, as desired,
by
driving cylinder 120. For example, in the illustrated embodiment lever 122 is
formed to
engage and drive rotation of the segment opposite to the one on which the
driver,
cylinder 120, is mounted. As illustrated, for example, a second detent 142 can
be
provided on barrel 138 into which protrusion 136 may engage. When engaged in
second detent 142, the protrusion may engage and drive segment 110 to rotate
with the
actuation lever as it is driven to rotate by the cylinder. Thus, engagement
between
protrusion 136 and second detent 142 may act to permit the engaged segment to
be
driven to open or close, as actuation lever 122 is moved.
It will also be appreciated that the protrusion and one or more detents act as
cam
surfaces and the positions of the protrusion and the detents may be reversed
so that the
detents are positioned on the actuation lever and the protrusion is positioned
on the
barrel of the segment to be driven. Also, the protrusions and the detents may
be
formed in various ways such as those shown or by smaller forms, or with more
angular
definition, etc.
Hinge 114 may be formed to permit the axial movement of barrel 138 along hinge
pin
123. For example, the height h of barrel 138 may be less than the distance
between the
fixed structures about hinge pin 123 on either side of the barrel. This allows
some axial
movement of the barrel along pin 123. If desired, a biasing member, such as a
spring
150 or other compressible member may be positioned to bias barrel 138, and
therefore
the segment to which barrel '138 is attached, down against the actuation lever
and into a
locked position. When using a spring 150, any movement to raise the barrel
along the
hinge pin must act against and overcome the force in the spring.
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Extension and retraction of the cylinder drives actuation lever 122 to rotate
about hinge
pin 123 to drive operation of the segments. For example, when the cylinder
retracts,
actuation lever 122 is rotated along arrow B and first raises segment 110
axially relative
to the other segment such that the locking mechanisms become disengaged. Then,
by
engagement of segment 110, lever 122 drives the segments to rotate open about
the
hinge. When it is desired to close the elevator, the cylinder may be driven to
extend
and push the actuation lever to rotate about hinge pin 123 with protrusion 136
located in
detent 142, which will move the outboard end of the first segment toward the
outboard
end of the second segment to close the elevator. Once segment 110 hits against
end
112a of the second segment, rotation of the first segment is stopped and
protrusion 136
moves from detent 142 to detent 140. This allows barrel 138 and the segment to
drop
down into a locked configuration using hooks 130a, 130b and abutment 132
If desired, an automated elevator may also include a safety lock function to
prevent
inadvertent opening of its segments when the elevator is in use. In the
illustrated
embodiment, the power of cylinder 120 may be selected such that it is
sufficient to lift
one segment up relative to the other if the elevators are empty. However, the
cylinder
may be selected to provide insufficient drive to axially offset the segments
if the weight
of a tubular is bearing on the segment to be raised, (i.e. on edges 11 6a).
The cylinder
may be selected to simply stop moving when resistance is encountered.
Alternately,
the hydraulic system driving the cylinder may be provided with sensors and a
control
system selected to shut down the system when a pressure over a selected level
is
sensed in the cylinder.
An elevator as described herein can be automated such that it can be operated
to open
and close without manual handling. For example, with a power source and
control for
the driver, the elevator can be operated remotely by actuation and control of
the power
source. In an embodiment including a hydraulic cylinder, a hydraulic system
including
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lines, fluid supply and valves and control system can be used to operate the
elevator
substantially without the need for direct contact by a rig hand.
The elevator can include eyes 151 through which it is supported and moved
about in a
rig. For example, eyes 151 can be formed in various ways to accept
installation of
cables, link arms etc. hanging in the rig. The elevator may also accept
removable and
replaceable inserts 152 for permitting selection of the inner diameter of the
opening
between edges 116a and 116b.
The previous description of the disclosed embodiments is provided to enable
any
person skilled in the art to make or use the present invention. Various
modifications to
those embodiments will be readily apparent to those skilled in the art, and
the generic
principles defined herein may be applied to other embodiments without
departing from
the spirit or scope of the invention. Thus, the present invention is not
intended to be
limited to the embodiments shown herein, but is to be accorded the full scope
as
defined in the claims, whereiri reference to an element in the singular, such
as by use of
the article "a" or "an" is not intended to mean "one and only one" unless
specifically so
stated, but rather "one or more". All structural and functional equivalents to
the
elements of the various erribodiments described throughout the disclosure that
are
known or later come to be kriown to those of ordinary skill in the art are
intended to be
encompassed by the elements of the claims. Moreover, nothing disclosed herein
is
intended to be dedicated to the public regardless of whether such disclosure
is explicitly
recited in the claims. No claim element is to be construed under the
provisions of 35
USC 112, sixth paragraph, unless the element is expressly recited using the
phrase
"means for" or "step for".
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