U.S. patent application number 11/409683 was filed with the patent office on 2006-08-24 for horseshoe shaped elevator and method for using same.
Invention is credited to Donald E. Mosing, David L. Sipos.
Application Number | 20060185854 11/409683 |
Document ID | / |
Family ID | 46299319 |
Filed Date | 2006-08-24 |
United States Patent
Application |
20060185854 |
Kind Code |
A1 |
Mosing; Donald E. ; et
al. |
August 24, 2006 |
Horseshoe shaped elevator and method for using same
Abstract
A U-shaped elevator having no doors is provided with first and
second latching mechanisms which when contacted by the tubular to
be entrapped within the elevator move from a closed position to an
open position and which then return to a closed position as soon as
the tubular is entrapped within the elevator. The latching
mechanisms have a safety catch which prevents the tubular from
being inadvertently removed from the elevator. The safety latch
mechanism can only be activated by a handle which is manipulated by
hand by personnel working on the derrick utilizing the elevator.
The elevator has an open throat to receive tubulars that have
couplers or other features with a lower flange surface for lifting
a pipe string. The throat access has blocking members that are
movable to allow tubulars to move out of the gap unless the
blocking members are locked to prevent such movement. The blocking
members have latches biased toward a position to immobilize the
members. To allow tubulars to exit the throat, an unlocking
mechanism is actuated manually or by motorized means under remote
control.
Inventors: |
Mosing; Donald E.;
(Lafayette, LA) ; Sipos; David L.; (Lafayette,
LA) |
Correspondence
Address: |
THE MATTHEWS FIRM
2000 BERING DRIVE
SUITE 700
HOUSTON
TX
77057
US
|
Family ID: |
46299319 |
Appl. No.: |
11/409683 |
Filed: |
April 24, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10444425 |
May 23, 2003 |
7032678 |
|
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11409683 |
Apr 24, 2006 |
|
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|
09999344 |
Nov 15, 2001 |
6568479 |
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10444425 |
May 23, 2003 |
|
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|
09410706 |
Oct 1, 1999 |
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09999344 |
Nov 15, 2001 |
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Current U.S.
Class: |
166/379 ;
166/77.52 |
Current CPC
Class: |
E21B 19/06 20130101 |
Class at
Publication: |
166/379 ;
166/077.52 |
International
Class: |
E21B 19/16 20060101
E21B019/16 |
Claims
1. An elevator for lifting and lowering an oilfield tubular joint,
the elevator comprising: a) a body having adjacent arms separated
by a throat arranged to accept said oilfield tubular joint; b) a
throat access blocking member arranged to allow said oilfield
tubular joint to enter said throat; and c) said throat access
blocking member capable of being held in the closed state, but is
non-responsive to force applied by said tubular joint tending to
move out of said throat.
2. The elevator according to claim 1 wherein each of said blocking
members comprises a door which pivots on said body, wherein the
actuation of said blocking member is controlled pneumatically.
3. The elevator according to claim 1, wherein said blocking member
comprises a door which pivots on said body, wherein the actuation
of said blocking member is controlled hydraulically.
4. A method for entrapping and releasing a joint of tubular within
an elevator, comprising the steps of: Positioning said elevator,
carrying a latching member, above a joint of oilfield tubular;
lowering said elevator over said tubular to thereby entrap said
tubular within said elevator using said latching member; and
releasing the entrapment of said tubular.
5. A method for entrapping and releasing an oilfield tubular joint
within an elevator, comprising the steps of: a) positioning an
elevator, carrying a latching member; beside an oilfield tubular
joint; b) entrapping said tubular joint within said elevator by
pushing the elevator and the tubular joint into latching engagement
with each other; and c) releasing the entrapment of said tubular
joint.
6. An elevator for lifting and lowering a joint of oilfield
tubular, casing, the elevator comprising: a) a body having adjacent
arms separated by a throat arranged to accept said joint of
oilfield tubular; and b) one of said arms provided with a throat
access blocking member that is arranged such that the blocking
member responds to force delivered to said blocking member by said
joint of oilfield tubular to allow said oilfield tubular to enter
and/or exit said throat.
Description
RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser.
No. 10/444,425, filed on May 23, 2003, which is a
Continuation-in-Part of U.S. application Ser. No. 9/999,344, filed
on Nov. 15, 2001, now U.S. Pat. No. 6,568,478, which was a
Continuation-in-Part of U.S. application Ser. No. 9/410,706, filed
on Oct. 1, 1999, now abandoned.
FIELD OF INVENTION
[0002] The invention relates, generally, to pipe handling elevators
used for lifting and lowering oilfield tubulars, usually as strings
of pipe being tripped into or out of an oil or gas well.
BACKGROUND OF THE INVENTION
[0003] It is well known in the art of drilling, completion and
workover of earth boreholes in the oil, gas and geothermal
industries to run strings of oilfield tubulars into and out of such
boreholes, sometimes referred to as "tripping in" or "tripping
out". Such tubulars can be, for example, drill pipe, drill collars,
casing and tubing. It is also well known to use elevators in such
tripping in or out operations to lift or lower such tubulars out
of, or into the wells. The handling gear for such tubulars is
oftentimes much alike in principle for all sizes but the difference
in scale is impressive. Well casing with a diameter of six feet,
with a two inch wall thickness, is not uncommon.
[0004] Elevators in the prior art typically are hinged, heavy
clamps attached to a hook and traveling block by bail-like arms,
sometimes referred to simply as "bails". Such elevators oftentimes
use one or more doors which are themselves quite heavy, and which
may require two or three strong men to close or hinge the one or
two doors around the tubular. Doors are a common feature but there
are single door and split door types. One type simply hinges to
open to admit or eject pipe. In hoisting a joint of drill pipe, the
elevators are latched onto the pipe just below the tool joint
(coupling) which prevents the drill pipe from slipping through the
elevators. Similarly, in lifting casing or tubing, the sections of
such tubulars have either an upset end, i.e., one in which the O.D.
is larger than the primary diameter of the casing or tubing, or
they are joined together with a collar having an enlarged O.D. In
all of these type of operations, the elevator when hinged to the
closed position, i.e., when the one or two doors are closed shut,
the internal diameter of the elevator is less than the O.D. of the
end of the enlarged tool joint, upset, or collar to prevent the
tubular from slipping through the elevator.
[0005] Handling practices differ between small and rather large
diameter pipe. Each section of very large pipe will typically be
picked up from the horizontal position and swung to the vertical
for stabbing into the connection of the assembled tubular string.
Such large pipe, for example, large diameter steel casing, presents
special problems. When elevators are placed on the horizontal pipe
they have to pivot to orient the elevator throat opening downward.
That leaves the doors, on door-type elevators, swinging on hinges.
The doors on a large elevator may weigh several hundred pounds. To
close such doors, drilling crew men place themselves in hazardous
situations. The rigging devised to get the doors closed often is
creative, but risky.
[0006] An elevator with doors needs clearance for the doors to
swing in the closing arc under the pipe being engaged. The pipe has
to be elevated, or clearance otherwise provided, for the swinging
door.
[0007] The elevators discussed above are of the so-called"non-slip"
variety. There are other elevators which grasp the tubular and can
be used to then hoist or lower the tubular, but the grasping
elevators are typically used with the light weight tubulars.
[0008] The elevators of the "non-slip" variety have generally been
constructed with doors (generally, one or two) which open to allow
the insertion or removal of the tubulars. These doors have
traditionally been heavy, slow in operation, difficult to handle
and present a considerable safety hazard to the operator. Also, the
balance point of the elevator will change dramatically when the
doors are opened, thus exacerbating handling problems and adding
danger to the operator.
[0009] Especially with very heavy tubulars, for example, 20''-30''
casing, the tubular is initially in a horizontal position, laying
in place, for example, on or near the floor beneath a derrick, and
the hinged door elevator is lowered near the point of attachment to
the tubular. The derrick hands then are required to open the very
heavy door or doors, which may weigh several hundred pounds, to
allow the elevator to be placed over the tubular. Moreover, because
the door or doors must close around the tubular, the tubular end
around which the elevator is placed must be above the derrick
floor.
SUMMARY OF THE INVENTION
[0010] The present invention avoids the above mentioned
shortcomings by eliminating the troublesome door members. Retention
of the pipe is then accomplished by a system of multiple pipe
catches, which are automatically deployed after the insertion of
the pipe joint and which automatically retract during insertion of
a pipe joint. Importantly, since this elevator lacks swinging
doors, the element of the greatest safety concern is eliminated
and, the equilibrium of the elevator is undisturbed during
insertion or removal of pipe.
[0011] When a tubular approaches the elevator, according to the
present invention, the tubular first contacts the disconnector
arms. As insertion continues, the disconnector arms are swung away
in an arc-like path and this motion actuates the disconnector links
which disengage the safety latches, allowing the pipe catches
freedom to move. The continuing movement of the pipe into the
elevator next causes the pipe to contact the pipe catches directly
and pushes them out of the way against a nominal spring force.
After the pipe is fully seated into the elevator, the pipe catches
(no longer restrained by the pipe body) will automatically deploy
by means of spring power. The pipe is now mechanically entrapped
and cannot fall out of the elevator. As a function of the
mechanism's geometry, the greater the force from the pipe resting
against the catches, the greater will be the resistance to opening.
The pipe catches, in effect, become self-energizing. In fact, it
will not be possible to manually open the elevator if a side force
against the catches is present. This feature is an additional
safety benefit.
[0012] In practicing the methods according to the present
invention, elevators can be dropped or lowered onto a horizontal
tubular, or swung against a vertical tubular to latch around the
tubular, thus by avoiding all or most of the problems associated
with using hinged door elevators.
[0013] The present invention comprises a horseshoe, or "U" shaped
body having first and second extending arms separated by a throat
to accept a pipe or other tubular. On each arm a blocking member
imposes into the passage to and from the throat and either blocking
member will prevent pipe (within the elevator rating size) from
moving out of the throat of the elevator. The blocking member is
spring biased to the blocking, or closed state. In the closed
state, a spring biased security lock goes to the locked state, and
the blocking member is immobilized in the closed state. There are
two ways to free the blocking member. One way is for pipe to be
urged toward the throat where it engages an enabling lever which
lifts the security lock and frees the blocking member to move to
admit pipe to the throat. The second way to manipulate the blocking
member is to activate a dumping lever which lifts the security lock
and moves further to move the blocking member away from the throat
to permit pipe to move out of the throat.
[0014] The elevator has no structure that prevents the elevator
from engaging pipe lying on a rig floor. The elevator freely pivots
within the loops of bails which engage ears, one on each side of
the body.
[0015] Not all elevators are suspended from the traveling blocks by
bails, the term used herein represents any of the many contrivances
serving the equivalent function in suspending elevators from
traveling blocks or the equivalent hoisting apparatus.
[0016] In the preferred embodiment, and as a special feature of the
invention, the ears are positioned such that the lift vector,
originating at the transverse line about which the ears rotate
within the bail loops, passes some distance from the centerline of
pipe, when positioned for lifting, within the throat. With an open
throat, the periphery of the ledge that engages the lifting surface
of the pipe, normally the lower surface of a connector, represents
an area that has a geometric center shifted toward the back of the
throat. Ideally, but not in a limiting sense, the extended lift
vector passes through, or near that geometric center.
[0017] These and other objects, advantages, and features of this
invention will be apparent to those skilled in the art from a
consideration of this specification, including the attached claims
and appended drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0018] For a further understanding of the nature and objects of the
present invention, reference should be had to the following
detailed description, taken in conjunction with the accompanying
drawings, in which like elements are given the same or analogous
reference numbers and wherein:
[0019] FIG. 1 is a diagrammatic view of a prior art, oilfield
tubular elevator;
[0020] FIG. 2 is a diagrammatic view of a second prior art,
oilfield tubular elevator;
[0021] FIG. 3 is a top plan view of the elevator according to the
present invention;.
[0022] FIG. 4 is an expanded view of a latch mechanism used with
the elevator illustrated in FIG. 3 according to the present
invention;
[0023] FIG. 5 is a series of top plan, sequential views of the
elevator according to the invention, illustrating the manner in
which the tubular is trapped inside the elevator;
[0024] FIG. 6 is a top plan view of an elevator according to the
present invention illustrating an additional feature of the
invention;
[0025] FIG. 7 is an enlarged top view of a portion of the elevator
of FIG. 6 illustrating an alternative embodiment of the
invention;
[0026] FIG. 8 is a sectional view taken along the section lines 8-8
of FIG. 7;
[0027] FIG. 9 is a top plan view of an alterative elevator
according to the present invention;
[0028] FIG. 10 is a top plan, cutaway view of a portion of the
elevator illustrated in FIG. 9 in accordance with the present
invention;
[0029] FIG. 11 is a top plan view of an additional alternative
embodiment of an elevator in accordance with the present
invention;
[0030] FIGS. 12(a) and 12(b) are top plan views of yet another
alternative embodiment of an elevator in accordance with the
present invention;
[0031] FIG. 13 is across-sectional view taken along the section
lines 10-10 illustrated in FIG. 10;
[0032] FIG. 14 is a combined top plan view and a side elevational
view of a conventional square shouldered oilfield tubular such as
very heavy oilfield casing; and
[0033] FIGS. 15(a) and 15(b) are top plan view of yet another
embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Referring now to the drawings in more detail, FIG. 1(a)
illustrates a top plan view of a hinged door elevator which is
commonly used in the prior art. The prior art elevator 10 has a
donut shaped body 12, having a center orifice 14 for encircling a
tubular 16 such as is illustrated in FIG. 1(c). The elevator 10 has
a pair of ears 18 and 20 having holes 19 and 21, respectively, to
which the bales (not illustrated) can be attached. The elevator 10
is quite thick, for example, 8 to 10 inches thick, to have the
required strength for picking up tubular strings such as large well
casing which weigh in the hundreds of thousands of pounds. The
elevator 10 has a door 24 which is made to rotate about a pivot pin
26 to open or close the door 24. As illustrated, the door 24 is in
the closed position and is latched to the remainder of the elevator
10 to secure it into position. When the door 24 is to be opened to
allow a tubular within the orifice 14 to be released, the door 24
is unlatched and pivoted around the pivot pin 26 as shown by the
rotational arrow 28.
[0035] FIG. 1(b) and 1(c), respectively, illustrate a top plan view
of a tubular 16 to be entrapped within the elevator 10 and an
elevated, partial view of the tubular 16. The tubular 16 has an
upset, enlarged end portion 30 having an outside diameter 32 as
measured between the two lines 34 and 36. The tubular 16 also has a
primary section 40 below the upset portion 30 which has a reduced
diameter as measured between the two lines 42 and 44. The portion
40 of the tubular is sized to fit within the interior orifice 14 of
the elevator 10 as illustrated in FIG. 1(a). Whenever the door 24
is opened, the elevator 10 fits around the tubular 16 at a point
along the tapered surface 50 of the tubular 16. As is well known in
the art, the tubular 16 also includes a passage 52 along its length
for allowing drilling fluid or other fluids to pass therethrough
when the tubular is in an earth borehole (not illustrated).
[0036] In the operation of using the prior art elevator illustrated
in FIG. 1, when it is desired to have the elevator 10 latch onto
the tubular 16, whether from the horizontal or vertical positions,
the door 24 has to be opened to allow the remainder of the elevator
10 to latch onto the tubular 16 at a point just beneath the upset
portion 30. It should be appreciated that when the tubular is very
heavy, for example 20'' to 30'' heavy steel casing, the elevator 10
is quite large, weighing several hundred pounds, and it requires a
great amount of human effort and exposure to safety hazards to open
the door 24 and engage the tubular 16 with the elevator 10.
[0037] It should be appreciated that although FIG. 1(a) illustrates
a prior art elevator having a single door which pivots around a
pivot pin 26, the prior art also includes a pair of doors (not
illustrated) which together accomplish somewhat the same function
as the door 24, but which are each only half the weight of a single
door to allow the two doors to be opened and closed manually easier
than a single door.
[0038] Referring now to FIG. 2, there is illustrated another type
of prior art elevator 60 which has no doors, but which depends upon
the weight of the tubular being hoisted or lowered to maintain the
tubular within the interior of the elevator 60. This type of
elevator 60 is typically used by those in the prior art to raise or
lower much more light weight types of downhole pipe, such as solid
sucker rods, hollow sucker rods and light weight tubing. Elevator
60 has a pair of attachment rods 64 and 66 around which bales can
be pivoted thereabouts, allowing the bales to be attached to a hook
and traveling block as discussed above with respect to the prior
art elevator of FIG. 1.
[0039] The light weight tubular 62 of FIG. 2 has an upset end 70
sized to ride on the top of the elevator 60 while the primary
portion of the tubular 62 below the upset end portion 70 is sized
to fit through the side opening 72 of the elevator 60. This type of
elevator is normally not used to handle the very heavy tubulars
because of not having a means of entrapping the tubular within the
elevator in a secure manner.
[0040] Referring now to FIG. 3(a), the elevator 100 is illustrated
in this preferred mode of the invention as being essentially
U-shaped, sometimes referred to as having a horseshoe shape. A
first latching mechanism 102 and a second latch mechanism 104 are
located, respectively, within the two arms 106 and 108 of the
U-shaped elevator 100. The two arms 106 and 108, together with the
arcuate end section 105 form the U-shape. A "stick figure"
illustration of a human being 110, which typically would be a rig
hand working on the derrick in tripping the tubulars in or out, is
illustrated as having his right hand on the elevator handle 112.
The latch mechanism 104 is illustrated as being in the open
position, whereas the latch mechanism 102 is in a closed position,
as will be explained in more detail with respect to FIG. 4,
hereafter. Although explained in more detail with respect to FIG. 4
and FIG. 5, it should be appreciated that as the pipe or other
tubular enters the open end of the horseshoe shaped elevator 100,
the tubular will contact the latching mechanisms 102 and 104,
causing both of them to assume the open position as shown in FIG. 3
for mechanism 104. As the tubular proceeds further into the
interior of the U-shaped elevator 100 the mechanisms 102 and 104
will return to the closed position as illustrated with respect to
mechanism 102 of FIG. 3, thus entrapping the tubular within the
interior of the elevator 100.
[0041] Referring now to FIG. 4, the enlarged view of the latch 102
is now described in greater detail. It should be appreciated that
the latches 102 and 104 are in cut-outs in the sides of arms 106
and 108, respectively, of the elevator 100, and are not located on
the top surface of the elevator 100. The top surface of elevator
100 is sized to be smaller, in its internal diameter, than the
external diameter of the upset end of the casing being raised or
lowered.
[0042] The latch mechanism 102 in FIG. 4 includes a disconnector
arm 130 having a wear pad 154 which will be contacted first by the
tubular to be entrapped. The arm 130 is pivotable about a pivot rod
132 which, as illustrated in FIG. 3(b), traverses the width of arm
106. A spring 149 encircles the pivot rod 132, and has a first end
155 located against the back surface of the wear pad 154, and a
second end 151 located against the elevator handle 152 which is
used merely to hand position the elevator 100, if and when
needed.
[0043] A disconnector link 134 has a first end connected to the
disconnector arm 130 and a second end connected to a safety latch
plate 120. The plate 120 has a recess 126 sized to receive a rod
124, which as illustrated in FIG. 3(b), traverses the width of arm
106.
[0044] Further in FIG. 4, the plate 126 is illustrated as being
pivotable about a rod 122, which has a spring 160 encircling the
rod 122 and having a first end located against one end of the
disconnector link 134 and a second end connected within a manual
handle 170. The handle 170 is illustrated as shorter than its
actual length, which may be one to two feet long for case of
operation.
[0045] The tubular catch 131 is configured from a hard metal, for
example, steel, and is thick enough and strong enough to withstand
any forces exerted by the entrapped tubular, and has an arcuate
lower surface 133 closely approximating the curvature of the
entrapped tubular, for example, as illustrated in step 10 of FIG.
5. The catch 131 also pivots around the pivot rod 132, and has a
width closely approximating the width of the arm 106.
[0046] FIG. 3 also illustrates a bale attachment member 112, one of
which is attached to each of the arms 106 and 108, allowing the
elevator 100 to be used with a traveling block (not
illustrated).
[0047] In the operation of the latch mechanism 102 of FIG. 4, the
latch is illustrated as being in the closed position, exactly the
same position as if a tubular were trapped inside the elevator 100.
The latch mechanism 104 of FIG. 3, which is a mirror image of latch
mechanism 102, would also be in the closed position. As the tubular
to be entrapped within the elevator approaches the elevator, the
tubular first contacts the wear pads of the disconnector arms of
the two latches 102 and 104, (e.g., wear pad 154 of arm 130 of
latch 102).
[0048] As insertion continues, the disconnector arms are swung away
in an arc-like path and this motion actuates the disconnector links
which disengage the safety latches, e.g., plate 120, allowing the
pipe catches, e.g. catch 131, freedom to move. The continuing
movement of the pipe into the elevator next causes the pipe to
contact the pipe catches directly and pushes them out of the way
against a nominal spring force. After the pipe is fully seated into
the elevator, the pipe catches (no longer restrained by the pipe
body) will automatically deploy by means of spring power. The pipe
is now mechanically trapped and cannot fall out of the elevator. As
a function of the mechanism's geometry, the greater the force from
the pipe resting against the catches, the greater will be the
resistance to opening. The pipe catches, in effect, become
self-energizing. In fact, it will not be possible to manually open
the elevator if a side force against the catches is present. This
feature is an additional safety benefit.
[0049] It should be appreciated that as the tubular to be trapped
within the elevator touches the disconnector arm such as arm 130 in
FIG. 4, the disconnector link 134 causes the safety latch plate 120
to disengage from the rod 124. As the tubular moves further past
the catch 131, the plate 120 swings into position such as is better
illustrated for latch mechanism 104 in FIG. 3, which illustrates
the disconnector link 134 as being essentially perpendicular to the
longitudinal axis of the arm 108. In that position, the latch 104
is in the open position and allows the tubular to be further
inserted within the interior of the elevator 100. As the tubular
goes past the latch mechanisms 102 and 104, the latch mechanisms
102 and 104 return to their closed position such as is illustrated
by the latch mechanism 102 in FIG. 3.
[0050] When the tubular which is entrapped within the elevator 100
is in a position which no longer requires the elevator 100 to be
used, the handle 170 illustrated in FIG. 4 is rotated manually to
return the latch mechanism 102 to its open position. The
corresponding handle for latch mechanism 104 is similarly rotated,
and with each of the latch mechanisms 102 and 104 in the open
position, the elevator 100 is easily removed from the tubular.
[0051] Thus, it should be appreciated that in utilizing the
apparatus and method herein disclosed, whenever it is desired to
attach the elevator according to the invention around a tubular,
whenever the tubular is in a horizontal or near horizontal
position, the only step required to attach the elevator to the
tubular is to drop the elevator, or lower the elevator onto the
tubular and the latching mechanisms herein described will entrap
the tubular with no additional steps required. Such a method is
illustrated by means of the sequential steps of FIG. 5 in which the
elevator 100 is lowered onto the horizontal tubular 200. Similarly,
if the tubular is in a vertical position, the elevator can be moved
into the latching position merely by positioning the elevator up
against the tubular and pushing the two elements together i.e., the
elevator against the side of the vertical tubular.
[0052] FIGS. 6, 7 and 8 illustrate some additional features and
alternative embodiments of the invention. FIG. 6 shows the U-shaped
elevator 1 with a pipe section P in the throat 2. Latch 3 in arm 1a
is in the closed position to retain the pipe in the throat. Latch
4, in arm 1b, is in the open position to allow pipe to move in or
out of the throat. Latches 3 and 4 correspond, for the most part,
to the latches 102 and 104 previously described herein, both as to
structure and as to function.
[0053] Ears 1d and 1c of the elevator 1 are situated such that
their centerline passes some distance d toward the throat from the
pipe centerline, identified as PCL in FIG. 6. Point LV is the
origin of a lift vector when a pipe load is lifted by a pair of
bails (not illustrated) which engage the ears 1d and 1c,
respectively. The ears can rotate in the loops of the bails (not
shown) which suspend the elevator from the traveling block. When
lifted pipe is vertical, the pipe usually has a top coupler with a
downwardly facing plane surface that rests on the area 1 e of FIG.
6. With the area interrupted by the throat gap, the geometric
center of the lift area is usually near the lift vector LV. This is
an optional feature and the distance d is a design choice
influenced by elevator size and the nature of the expected pipe
string load.
[0054] FIG. 7 illustrates alternative details of latch 3. In arm
la, post 7 bearingly supports rotating members 5 and 6. Member 5 is
the blocking member that prevents movement of pipe into and out of
the throat. Member 6 is the incoming load sensor lever. When
engaged by incoming pipe, lever 6 pivots about post 7, pushes link
8 to rotate member 10 about secondary post 9 to lift recess 10a
clear of post 11. The blocking member 5 then rotates about post 7.
Post 9 is mounted on member 5 and swings with member 5. Posts 11
and 7 are secured within the arms 106 and 108 of the elevator 100
illustrated in FIG. 3.
[0055] The access to the throat can be cleared by pulling handle 12
toward the free end of the arm. That action rotates member 10 about
secondary post 9 and all elements mounted on member 5 rotate
counterclockwise to pull blocking member 5 out of the throat
access, to free pipe to move from the throat of the elevator.
[0056] Springs 15 and 16 bias the blocking member to the closed
state and bias the security lock, element 10 on post 11, to the
locked state.
[0057] Hand grip 14 is used for manually moving the elevator and
glove shield 13 to keep gloves out of the mechanism.
[0058] Alternatively, a powered version of the latch mechanism
leaves the option of manual manipulation of the latches
unencumbered. A motor 20 rotates (see FIG. 3) post 7, as an output
shaft of the motor 20. The post 7 is keyed to element 6 and
bearingly situated in plates 1a and 1aa as well as blocking member
5. Motor 20, can be secured to plate 1aa, and driving pinion 21, in
mesh with gear teeth 6a on lever 6, as an alternate arrangement,
requiring cutaway 5a in one side of the blocking member 5.
[0059] The mounting and configuration of driving motor 20
accommodates either fluid powered or electric drive systems. Open
center valving serves motor 20, if fluid is used, to facilitate
free wheeling of the motor for manual latch operation. The motor 20
can be mounted on either plate 1a or plate 1aa to project either
above or below the elevator.
[0060] FIG. 8 shows plates 1a and 1aa, and only the elements
involved in adaptation for motor use of the latching mechanisms
described herein. Plates 1a and 1aa are continuations of the lower
and upper surface plates defining the envelope of the body of the
elevator which is currently of weldment construction. Current
construction practices are not to be construed in a limiting
sense.
[0061] Referring now to FIG. 9, an alternative embodiment of the
present invention is illustrated in more detail. The
`Articulated-Cradle Elevator` ("A.C.E.") is a tool designed to lift
`square shouldered` tubulars quickly and safely. Tubulars may be
lifted either vertically or from the horizontal. This ability
allows the A.C.E. to function efficiently in dual modes as both the
main tubular string-elevator and as a single joint elevator.
[0062] In the current, preferred embodiment, the A.C.E. consists of
a body 200 that, functions as the basic platform to which, the
lifting ears 202 and the cradles 204 are affixed. The body 200
structure is a beam, fabricated or otherwise, resembling a
rectangular hollow tube--other shapes may be appropriate depending
on tool size, capacity or other economic factors--formed into a
three-sided "U" shape, as illustrated in FIG. 13, leaving one side
201, called the throat, open for movement of the oilfield tubular
206 into or out of the A.C.E. The lifting ears 202 are designed for
a specific size bail, depending on the intended capacity of the
tool. The cradles 204 are designed to wrap around the tubular 206,
under the square shoulder 203, illustrated in FIG. 14, to a far
more substantial degree than is possible with `Horseshoe` type
elevators, illustrated in FIGS. 3-8 herein, whose very nature
typically limits the contact to a maximum of 180 degrees. Also, the
cradles 204 greater bearing surface of up to approximately 250
degrees is centrally located in relation to the centerline 205 of
the lifting ears 202, thus allowing the elevated tubular to hang
perfectly straight. This latter feature is sometimes not possible
with Horseshoe type elevators of large capacity due to their
eccentric bearing surface in relation to the ears.
[0063] The ability of the cradles 204 to wrap around the tubular
206 to such a great degree is a function of their being able to
pivot to open and closed positions. In the open position the
cradles 204 swing out of the throat 201 of the body 200 so that, a
tubular 206 may move unhindered into or out of the body 200 and in
the closed position, the cradles 204 swing into the throat 201 of
the body 200 and encircle the now trapped tubular 206 centrally
over the lifting ears 202. The cradles 204 are attached to the body
200 by means of pivot pins 207 and are urged to the normally open
position by the cradle-open springs 209. Whenever a tubular 206
enters the open A.C.E. it pushes against the back of the cradles
204 moving them to the closed position. When the closed position is
attained, the sliding lock blocks 211 are freed from the open
position and are urged backward to the lock position by the lock
springs 213. The unlocking handles 215 are now in the extreme back
of their respective slots and this provides reliable visual
indication of lock status. The tubular 206 is now securely trapped
within the closed cradles 204. To remove the tubular 206, the
sliding lock blocks 211 must be moved to the forward position
either manually or by a motor. Unlocking handles 215 are provided
for manual operation. As soon as the sliding lock blocks 211 are
moved out of the way, the cradle-open springs 209 articulate the
cradles 204 pivotally to the open position, ejecting the tubular
206 from the A.C.E. and trapping the sliding lock block 211 in the
forward or open position.
[0064] The improvements are: (1) Greater shoulder bearing area via
the cradles more generous wrap around and centralized location,
insuring less stress on the collar of the tubular and providing
greater lifting capacity; (2) Centralizing the tubular over the
lifting ears for a perfectly straight lift which, aids stabbing
into the previous joint; (3) Superior lock strength by means of a
solid lock block rather than numerous pins and linkages, to assure
the tubular remains securely within the A.C.E.; (4) Simplified
operation by means of a straight pull, single motion handle; (5)
Increased operator safety due to the operating handles being far
removed from the lift bails to preclude pinching injuries; (6)
Simple, accurate, reliable visual indication of lock status, thus
eliminating the need for operator intervention to ensure
lock-up.
[0065] Referring now to FIG. 10, there is illustrated another view
of the embodiment of the present invention illustrated in FIG. 9.
In FIG. 10, there is illustrated, essentially, what is the
embodiment of FIG. 9 and its mirror image. The parts are
essentially in duplicate, and numbered the same and shows
essentially the same parts, in the same positions, as illustrated
in FIG. 9. With the release handles 215 in the open position, the
springs 209 will cause the cradles 204 to move to the "open
position" and allow the casing or other tubular 206 to be moved
into the position within the interior of the cradles 204. By
releasing the handles 215, the cradles 204 will wrap themselves
around the exterior of the casing 206 but underneath the square
collar having shoulder 203 illustrated in FIG. 14. As discussed
herein above, the cradles 204, respectively, will pivot around the
pivot pins 207 and the cradles can be moved into the throat 201 of
the "U" shaped body 200 illustrated in FIG. 13. This is made
possible by the cutaway section 213 of each of the cradles 204 to
allow the cradle 204 to fully pivot as desired, under which the
cutaway section 213 can slide into the throat of the body 200. Once
the tubular 206 is fully within the confines of the cradles 204,
whereby the cradles 204 can ride underneath the square shoulder
surface 203 illustrated in FIG. 14, the cradles are locked into
position and cannot be unlocked until the manual release handles
215 are activated, or alternatively, the manual handles 215 can be
actuated by a motor such as a pneumatic motor or hydraulic motor to
release the handles 215 and allow the tubular 206 to be removed
from the body 200. It should be appreciated that in FIG. 10, the
lifting ears to which the bails are attached are not illustrated
but they are each identical with the lifting ear 202 as illustrated
in FIG. 9.
[0066] In operation, of the device as illustrated in FIGS. 9 and
10, after the cradles are fully in place underneath the square
shoulder 203 illustrated in FIG. 14 of the tubular 206, the
elevator having the body 200, is raised or lowered to move the
tubular 206 into the vertical or horizontal positions as desired.
When it is desired to release the tubular 206 from the apparatus
illustrated in FIG. 10, the release handles 215 are manipulated,
either manually or by a motor, for example, a pneumatic or
hydraulic motor or two such motors to handle the two handles 215,
to cause the cradles 204 to move completely out of the path of the
tubular 206 to enable the tubular to be fully released from the
elevator illustrated in FIG. 10.
[0067] Referring now to FIG. 11 there is illustrated yet another
alternative embodiment of the present invention. The Horseshoe body
300 is comprised of two lift ears 302 and one not shown and two
bearing surfaces, the bearing 304 and one not shown. Affixed to the
body 300 are the lift pins, one lift pin 306 and one not shown, and
two flaps, the flap 308 and one not shown. The Flap 308 is rotated
on the hinge pin 310 out of body opening 312 to allow the tubular
314 to enter into body 300. This may be accomplished manually or by
lowering the body 300 over the tubular 314. Once the tubular 314 is
fully inserted into body 300, flap 308 automatically, by spring
force or by motor means, is returned to the closed position as
shown in FIG. 11, trapping the tubular 314 within the body 300.
Upon lifting the Horseshoe elevator 300, the collar of the tubular
314 rests evenly on top of flap 308 and on bearing surface 304, as
well as on their mirror image counterparts.
[0068] With this system the lift pin 306 is located on the center
of the tubular 314 so that the weight of the tubular 314 is carried
symmetrically on the axis of the tubular 314 and the tubular 314
hangs straight.
[0069] It should be appreciated that in using the apparatus
illustrated in FIG. 11, the Horseshoe Elevator 300 illustrated in
FIG. 11, has a mirror image on its other side such that there are
two of everything illustrated in FIG. 11. Thus, there are two sets
of wear surfaces 304, two sets of Flaps 308, etc., which all work
together. In the use of the elevator illustrated in FIG. 11, the
flap 308 is rotated out of the way by causing it to pivot around
the pivot pin 310 until the tubular string 314 can be moved into
the opening within the Horshoe Elevator 300. After the tubular 314
is in place within the elevator, the flap 308 on each side is
rotated to be around the tubular 314 and the elevator 300 can be
manipulated in the usual ways to either raise, lower or otherwise
manipulate the tubular 314. It should be appreciated, in using the
elevator illustrated in FIG. 11, that to capture the tubular within
the elevator 300, the flap 308 is rotated to ride under the square
collar 203 of the tubular 206 (or the tubular 314, as the case may
be). This causes the wear pad 304 and the flap 308 to both be under
the square collar on each side of the elevator illustrated in FIG.
11. In use, it should be appreciated that the two sets of flaps 308
and the two sets of wear pads 304 are each under the square collar
of the tubular 314 which allows the tubular 314 to be raised,
lowered or otherwise manipulated because all of the weight of the
tubular will be born by the two sets of wear pads 304 and the two
flaps 308.
[0070] Referring now to FIG. 12, there is illustrated a single door
elevator 400 which has a body 402 and the single door 404 which
pivots around a point on the line 406. Before the door 404 is
rotated to open up the elevator 400, it is secured to the body 400
by any conventional latching mechanism 408 as desired.
[0071] As seen further in FIG. 12a and 12b, the door 404 is rotated
through the use of a fluid driven activator 410 which can be used
to rotate the door 404 to the open position or to rotate it in the
reverse direction to close the door 404 against the body 402 to
allow the latching mechanism 408 to hold the body 402 and the door
404 in the secured position. The fluid driven actuator 410 is
powered by a pump 412 which can be either pneumatic or hydraulic
and supplies the fluid under pressure through the flexible line 414
to the actuator device 410.
[0072] As illustrated in FIG. 12b, the dotted line 416 illustrates
the path through which an oilfield tubular can be moved without
being forced into contact with any point of the elevator. This
leaves an unimpeded path for the tubular such as the tubular 206 of
FIG. 14. This feature is accomplished, by always having the point
418 of the door to the left hand side of the dotted line 416 as
viewed in FIG. 12b. It should be appreciated that if the point 418
is to the right side of the dotted line 416, the tubular moving
into or out of the elevator may very well bump the point 418 of the
door and impede the travel either into or out of the elevator
illustrated in FIGS. 12a and 12b.
[0073] Referring now to FIGS. 15a and 15b, there is illustrated a
two-door elevator 500 having a body 502 and first and second doors
504 and 505 which can be maintained in the closed position by a
latching mechanism 508. The door 504 is open and/or closed by the
actuator 510 which is controlled by a fluid pump 512 connected
between the pump 512 and the actuator 501. In a similar vein, the
door 505 is opened or closed by the actuator 511 controlled by a
fluid pump 513 through a flexible line 515.
[0074] It should be appreciated that the pumps 512 and 513 can be
individual pumps or can be the same pump to drive the actuators 510
and 511, and can be either pneumatic or hydraulic as desired.
[0075] FIG. 15b also illustrates a pair of dotted lines which are
parallel to each other and which define the area into which the
doors 504 and 505, respectively, are rotated to make sure that the
respective points 520 and 522 are clear of the tubular as such
tubular leaves or enters the elevator 500. Thus, when the door 504
is rotated to cause its point 520 to be on or to the left side of
the line 516 and the door 505 is rotated to cause the point 522 to
be on or to the right side of the dotted line 518, the tubular to
be moved into or outside the elevator will always have an
unobstructed path. This characteristic is advantageous in that it
will prevent the doors 504 and 505 from being damaged by the heavy
weight oilfield casing as it is moved into or outside of the
elevator 500, which also prevents damage to the tubular. This is,
of course, the very same reason for maintaining the point 418 of
the door 404 in FIG. 12b on or to the left side of the dotted line
416.
[0076] From the foregoing, it will be seen that this invention is
one well adapted to attain all of the ends and objects hereinabove
set forth, together with other advantages which are obvious and
which are inherent to the elevator described and illustrated
herein.
[0077] It will be understood that certain features and
sub-combinations are of utility and may be employed without
reference to other features and sub-combinations. This is
contemplated by and is within the scope of the claims.
[0078] As many possible embodiments may be made of the elevator of
this invention without departing from the scope thereof, it is to
be understood that all matter herein set forth or shown in the
accompanying drawings is to be interpreted as illustrative and not
in a limiting sense.
[0079] While one or more of the preferred embodiments of the
present invention contemplates the use of an elevator having a
U-shape with parallel arms, the arms can either be parallel, or
inclined slightly towards each other or even inclined slightly away
from each other. Moreover, while the present invention contemplates
that a given elevator will have a single pair of latching
mechanisms, the elevator according to the present invention could
also include two or more pairs of latching mechanisms which could
be used to entrap a tubular within the elevator.
* * * * *