U.S. patent number RE29,995 [Application Number 05/863,535] was granted by the patent office on 1979-05-15 for dual elevators.
Invention is credited to William C. Guier.
United States Patent |
RE29,995 |
Guier |
May 15, 1979 |
Dual elevators
Abstract
This invention relates to an improved elevator as used in the
drilling industry for latching onto and transporting drill pipe.
The improvements are particularly adaptable for elevators used in a
dual automatic elevator system as described in U.S. Pat. No.
3,063,509. The improvements include: (a) an arrangement wherein an
elevator base may be utilized to accept a variety of different
sizes of drilling pipe with a variety of different shoulder
configurations on the tool joint end of the drilling pipe; (b) an
elevator having a removable base so that the elevator may be
utilized either for the dual automatic system of U.S. Pat. No.
3,063,509 or as an elevator as used in the commonly practiced
single elevator drilling system; (c) an elevator having means for
remotely unlatching the door when it is desired to remove the
elevator from engagement with a drill pipe without requiring manual
unlatching of the door; and (d) means of adjusting the angle of
tilt of the elevator suspended by bails so that the elevator is
properly orientated for engaging a drill pipe. These advantages and
improvements are accomplished utilizing a removable bushing to
accept different sizes of pipe, in conjunction with a replaceable
door to match with each bushing, and the other improvements include
removable lower plate, a pivotally adjustable counterweight for
changing the angle of suspension of the elevator and hydraulically
controlled linkage means for unlatching the elevator door by remote
application of fluid pressure.
Inventors: |
Guier; William C. (Tulsa,
OK) |
Family
ID: |
24590934 |
Appl.
No.: |
05/863,535 |
Filed: |
December 22, 1977 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
645904 |
Dec 31, 1975 |
04035012 |
Jul 12, 1977 |
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Current U.S.
Class: |
294/90 |
Current CPC
Class: |
E21B
19/06 (20130101) |
Current International
Class: |
E21B
19/00 (20060101); E21B 19/06 (20060101); B66C
001/10 (); E21B 019/06 () |
Field of
Search: |
;294/90,91,12A,113
;24/249DP,263D,263DA ;166/77.5,85 ;175/85,195 ;214/2.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cherry; Johnny D.
Attorney, Agent or Firm: Head, Johnson & Chafin
Claims
What is claimed is:
1. An elevator apparatus handling stands of drill pipe in a mast or
derrick, comprising:
a. an elevator body having a central opening;
b. a hinged door at the front of said body to close said
opening;
c. a shaft journalled in said body in a direction from front to
back;
d. a latch arm affixed to the front end of said shaft, the latch
arm being movable from a first position where it overlaps a portion
of said door to latch it in the closed position to a second
position where it is clear of said door to unlatch it by rotation
of said shaft;
e. an operating means affixed to said shaft at the back of said
elevator; and
f. piston cylinder means connected between said operating means and
said elevator body for latching and unlatching said door.
2. An elevator as in claim 1 wherein said elevator body central
opening has an internal shoulder and including:
a bushing of a selected internal diameter and seating surface
suited to the specific diameter of the drill pipe to be carried and
of the same shape of the tool joint, the bushing having an external
diameter and configuration to match said body central opening and
to engage said internal shoulder, said central opening and central
bushing having a sector cut away as a door opening on the front
side; and
the inner surface of said door matching the inner surface of said
bushing such that when said door is closed, the contour of the
inner surface of said bushing and door are symmetrical.
3. An elevator as in claim 1 including:
adjustable counterweight means attached to said elevator providing
means of adjusting the angle of tilt of the elevator when pivotally
suspended from supporting bails.
4. An elevator as in claim 1 including:
a vertical arm adjustably supported to said body; and
a counterweight adjustably supported to said vertical arm.
5. An elevator according to claim 1 including:
a base removably affixed to the lower portion of said body.
6. An elevator according to claim 5 wherein:
said base includes opposed planar surfaces adaptable to slidably
support the elevator on parallel tracks.
7. An elevator according to claim 5 wherein:
said base has opposed ends each having means of receiving a bail
retainer thereto and wherein said body has integral opposed
outwardly extending bail receiving hooks, a portion of each having
a means of receiving a bail retainer therein; and
a bail retainer removably attached to said body hook portion and
said base opposed ends to retain bails received beneath said hook
portions.
8. An elevator for removably attaching to drill pipe for lifting
and transporting the same, comprising:
an elevator body having a central vertical drill pipe receiving
opening therethrough and opposed horizontally extending bail
receiving hook portions, the body having a door opening in the
front side thereof providing an opening of sufficient width to
receive drill pipe therethrough;
a door pivotally affixed about a vertical axis to said body and
movable between an open position exposing said door opening of said
body and a closed position;
a shaft journaled in said body from front to back;
a latch arm affixed to the front of said shaft and movable from a
first position engaging and retaining said door in the closed
position to a second position permitting said door to open;
an operating arm depending from said shaft at the back of said
body; and
a cylinder piston member connected between said operating arm and
said elevator body to selectably move said latch from said first to
said second position in response to fluid pressure.
9. An elevator for removably attaching to drill pipe for lifting
and transporting the same, comprising:
an elevator body having a central vertical drill pipe receiving
opening therethrough and opposed horizontally extending bail
receiving hook portions, the elevator body being pivotally
suspended about a horizontal axis through said hook portions, the
body having a door opening in the front side thereof providing an
opening of sufficient width to receive drill pipe therethrough;
a door pivotally affixed about a vertical axis to said body and
movable between an open position exposing said door opening of said
body and a closed position; and
an adjustable counterweight attached to said elevator providing
means of adjusting the angle of tilt of the elevator about said
horizontal axis.
10. An elevator according to claim 9 including:
an arm having an inner end and an outer end, the inner end being
pivotally affixed to said body and the arm being pivotally
adjustable in a plane perpendicular to said horizontal suspension
axis, said counterweight being affixed to the outer end of said
vertical arm.
11. An elevator according to claim 10 wherein said counterweight is
longitudinally positionable on said vertical arm. .Iadd. 12. An
elevator apparatus for handling strands of drill pipe in a drilling
mast, comprising:
an elevator body having a vertical central passageway therethrough,
the body having an upper end and a lower end, and having a side
opening in one side thereof communicating with the central
passageway, the side opening being of sufficient width to receive
drill pipe therethrough;
a pair of integral, opposed hooks extending from opposite sides of
said body to either side of said side opening providing means of
receiving bail links whereby the elevator body and pipe supported
thereby may be raised or lowered in the mast;
a door pivotally supported about a vertical axis to said body and
pivotal to an open position to fully expose said side opening to
permit pipe to be moved in or out of said body central passageway,
and pivotal to a closed position to retain pipe within said central
passageway;
an elevator base having a base central passageway therethrough of
diameter at least equal said body central passageway and having a
pipe receiving side opening in one side thereof communicating with
said base central passageway, the elevator base having opposed
ends;
means of detachably securing said base to said body wherein said
passageways and side openings are in alignment and said base
opposed ends and said body integral hooks are in a common vertical
plane;
means removably interposed between said elevator base opposed ends
and said body hooks for removably maintaining bail links in
engagement with said body hooks. .Iaddend. .Iadd. 13. An elevator
apparatus for handling strands of drill pipe in a drilling mast
according to claim 12 wherein said means removably interposed
between said elevator base opposed ends and said body hooks
includes a locking member pivotally secured to each elevator base
opposed end, each locking member configured to extend in one
position towards said body hook to prevent bail links from moving
out of engagement with said hooks and pivotal in another direction
to permit bail links to pass freely into or out of engagement with
said hooks;
and including spring means between said elevator base and each said
locking member normally urging said locking members in positions to
prevent bail links from disengaging contact with said body hooks.
.Iaddend..Iadd. 14. An elevator apparatus for handling strands of
drill pipe in a drilling mast according to claim 12 wherein said
body central passageway has a larger upper diameter and a smaller
lower diameter presenting an upper facing internal shoulder, and
including;
a bushing of internal diameter and seating surface suited to a
preselected diameter and shape of a drill pipe tool joint, with
said bushing having an external diameter and configuration to match
said body central passageway and to engage said internal shoulder,
said bushing having a cutaway as a side opening of sufficient width
to receive a drill pipe therethrough, said bushing being
positionable in said body with said body side opening, said base
side opening and the bushing side opening in registry, and wherein
the inner surface of said door matches the inner surface of the
bushing such that when said door is closed the inner surfaces of
said bushing and door are symmetrical. .Iaddend.
Description
CROSS REFERENCE TO RELATED PATENTS
This application is related to the Guier U.S. Pat. No. 3,063,509,
dated Nov. 13, 1962, entitled "Apparatus for Handling Stands of
Pipe." U.S. Pat. No. 3,063,509 is inserted by reference into this
application.
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for handling stands of pipe,
as when making up and breaking out long strings of pipe used in a
borehole for drilling wells. The apparatus is supported by a
travelling block suspended by cables in a drilling rig mast and is
adapted to encircle and support a string of drill pipe by
engagement with the tool joint of the end of the pipe. Devices of
this type are referred to in the petroleum drilling industry as
"elevators."
One of the problems with the present day elevators is that of
matching the elevator to the particular type of drill pipe being
used. In the industry today the use of 31/2 , 4, 41/2 and 5 inch
drill pipe is common. In addition, with any given size of drill
pipe there are a variety of different shoulder configurations on
the tool joints integrally formed at the end of the drill pipe. For
these reasons a wide variety of different elevators must be
manufactured and carried by supply houses to meet the demands of
the drilling industry. An object of this invention is to provide an
improved elevator which is capable of being utilized on a variety
of sizes of drill pipe, for instance, from 31/2 inches to 5 inches,
using the same elevator body with different small and relatively
inexpensive components
In Guier U.S. Pat. No. 3,063,509 there is described a useful and
effective apparatus and system for handling stands of drill pipe.
The system involves the use of an elevator of particular design
which has two shoulders and overhanging hooks, which can be engaged
respectively by two bails which are supported from the traveling
block. On the rotary table there are two horizontal spaced apart
parallel rails, one on each side of the drill pipe receiving
central opening. These rails are co-linear continuations of a pair
of rails supported on the floor of the derrick at the level of the
top of the rotary table. The elevator has a base which is adapted
to seat on the rails and be guided by the rails so that the
elevator can be moved horizontally from a position over the rotary
table to a position displaced along the rails from the rotary
table, where it can remain while the rotary table is turning, and
the pipe is drilling.
By the use of two elevators there is always one elevator on the
rails displaced from the rotary table while the second elevator is
raising or lowering pipe. When the pipe is lowered into the
borehole through the rotary table, it is supported in the elevator.
The bails are automatically released from the overhanging hooks and
slid along the rails where they are made to engage the overhanging
hooks of the second elevator, which can then be lifted to bring a
second stand of pipe, for example, to be joined with the pipe
supported in the elevator on the rotary table. After the new stand
of pipe is made up, the pipe is lifted by the second elevator, and
the first elevator is the removed from the pipe and is slid along
the rails to the waiting position. The pipe is then lowered and
supported in the rotary table by the second elevator, and so
on.
The elevators utilized in the dual automatic elevator system of
U.S. Pat. No. 3,063,509 includes automatic means for locking the
elevator rails to the elevator when the rails are engaged for
lifting the elevator. This automatic locking means is not required
if the elevator is utilized for the commonly used procedure wherein
only single elevators are employed. This invention provides
interchangeable bases to the elevator, so that an elevator body may
be utilized for the commonly employed single elevator system, or
with the use of a different base, the dual elevator system of U.S.
Pat. No. 3,063,509.
Another problem with elevators in use today is that they must
customarily be manually unlatched to release them from engagement
with drill pipe. This is particularly disadvantageous in a dual
elevator system. The present disclosure includes means whereby a
remotely controlled pressure signal may be employed to
automatically unlatch the elevator as desired.
Another problem encountered with the use of elevators is that they
sometimes are not properly inclined at the correct angle when swung
into position by an operator to engage and lock around a drill
pipe. Side door elevators, including the type illustrated in U.S.
Pat. No. 3,063,509, include a finger on the door which, when
engaged with a length of drill pipe, causes the door to close. This
works efficiently and the pipe is received satisfactorily within
the elevator as long as the axis of the opening through the
elevator is parallel to the axis of the drill pipe as the elevator
is swung into position to engage the drill pipe. Since elevators
are normally pivotally swung from the bails there presently exists
no easy way of controlling the angle of the elevator relative to
the bail. This invention provides a means of selectably varying the
angle of the axis of opening through the elevator relative to the
vertical so that it can be adjusted to be most convenient for use
by the operator in engaging drill pipe.
SUMMARY OF THE INVENTION
The disclosure herein provides an elevator of the side door type
having significant improvements over elevators as presently
utilized in the petroleum drilling industry. The elevator described
includes a body portion with interchangeable bushings and doors
which may be employed so that a single body portion may be adapted
to engage and transport a variety of sizes of drill pipe and a
variety of shoulder configurations on the tool joint ends of the
drill pipe. The elevator includes counterbalancing means to
selectably vary the attitude of the elevator as it is suspended by
bails and a removable base so that the elevator may be utilized in
a standard single elevator drilling system or with a different base
in the dual elevator drilling system as described in U.S. Pat. No.
3,063,509. Further, the elevator described herein includes
hydraulic means functioning by way of a cylinder piston and
linkages to control a latch for remotely unlatching the door of the
elevator.
OBJECT OF THE INVENTION
The primary object of this invention is to provide an improved
elevator for use by the petroleum industry.
It is a further object of this invention to provide an elevator in
which the central opening has a shoulder in which replaceable
bushings can be inserted, so that bushings can be provided with a
central opening diameter which is suited to the diameter of the
pipe to be used. Also, the contour of the central opening of the
bushing is designed to fit the contour of the tool joints. This,
elevators can be quickly converted from one size and type of drill
pipe to another by changing bushings. It is a still further object
of this invention to provide an elevator with replaceable doors
over the front opening, which doors are made with different
internal contour to suit that of the bushing which is being used in
the central opening of the elevator.
It is a still further object of this invention to provide a
door-latching mechanism which is operated by a pressure fluid
cylinder, through mechanical linkage.
Another object of this invention is to provide an elevator having
means of adjusting the angle of tilt to facilitate engagement with
drill pipe.
These and other objects in this invention by providing an elevator
which has a central opening which provides a shoulder, on which can
be seated one of a plurality of centralizing bushings, each bushing
of different internal diameter to suit a particular size of drill
pipe. The central opening of the bushings also provides a conical
contour or a shoulder which is designed to fit the tool joint of
the pipe. When a string of pipe is inserted through the door into
the opening of the elevator, the pipe will be supported by the tool
joint, so that slips or other means for supporting the pipe, which
have sharp teeth which can cut into the surface of the pipe, will
not be needed.
To fit the internal contour of the varous centralizing bushings, it
is part of the invention to provide a corresponding series of doors
for the elevator, each door having an internal surface when the
door is closed which matches that of the particular bushing which
is in place. Consequently, when the door is closed, the internal
surface is symmetrical and continuous and is adapted to provide
full support for the drill pipe.
A further improvement involves the use of a fluid pressure cylinder
mounted on the back of the elevator which operates through a lever.
A shaft carried from the back to the front of the elevator and a
latching arm attached to the shaft can latch or open the door of
the elevator.
Another improvement involves the use of a replaceable base for an
elevator body adapting the elevator for different usages.
Another improvement of this invention involves the use of an arm
bolted to the back surface of the elevator, the arm carrying an
adjustable counterweight, such that the rotational torque of the
counterweight acting on the elevator (when it is supported by the
bails, without pipe), rotates the elevator to an angle which better
fits the sloping position of the pipe. Thus the pipe fits into the
central opening more completely and easily and permits the door to
be closed with less force. In other words, when the elevator is
clamped around the pipe, the counterweights serve to align the axis
of the central bushing of the elevator to the axis of the pipe and
thus permits the door to close freely and be locked before the
weight of the pipe is placed on the elevator.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention and a
better understanding of the principles and details of the invention
will be evident from the following description taken in conjunction
with the appended drawings in which:
FIGS. 1 and 2 show plan and elevation views respectively of the
elevator of this invention and particularly illustrating the
replaceable bushing and door.
FIGS. 3 and 4 show plan and elevation views of a second embodiment
of this invention, providing detail of the latching mechanism.
FIG.5 is a side view of the embodiment of FIGS. 3 and 4 and
illustrates further details of the latching mechanism and the
counterweight.
FIG. 6 is a partial side elevational view showing further details
of the bail locking mechanism.
FIG. 7 is an isometric view of an embodiment of the replaceable
bushing which may be utilized in the elevator body.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular to FIGS. 1 and 2,
there is shown in plan and elevation one embodiment of the
invention. The body of the elevator is indicated by the numeral 10.
There are two shoulders 12 terminating in hooks 14 by means of
which the elevator and the pipe which may be supported from it, are
supported by the traveling block. A central opening 16 of the
elevator is provided by a cylindrical bore 18 with a larger bore 20
at the top, providing a shoulder 22. A separable busing 24 is
adapted to fit the bore 18 and 20 and the shoulder 22. In order to
affix to and elevate different sizes of drill pipe different
bushings 24 are employed. Each bushing 24 has an inner diameter 26
adapted to fit the particular drill pipe being used in the drilling
apparatus. The upper contour 28 of the bushing is designed to fit
the contour of the lower shoulder of tool joint on the end of the
drill pipe. This may be a conical seat as shown, or it might
involve a rectangular shoulder in case the lower surface of the
tool joint is square, and so on.
By having a group of bushings 24, each of the same outer diameter
and contour but with different internal diameters and contour, the
same elevator body 10 can be used for various types and sizes of
drill pipes.
As shown in FIG. 1, there is a front opening 30 of the central
opening 16 which, in operation of the elevator, is closed by a door
32 which is hinged about a pin 34 journaled in the main body of the
elevator. This door has a finger 36 which is part of the door. As
pipe moves into opening 16 (indicated by the dashed circle 38) it
contacts the finger 36, causing door 32 to be rotated about the
shaft 34 and close around the pipe. As the door rotates and the
pipe moves into the opening 16 the finger recedes into a cavity 40
shown in FIG. 2, which is cut into the bushing 24 and the wall of
the elevator.
The internal surface 32A of the door 32 is configured such that
when closed it must form a continuation of the internal surfaces 26
and 28 of bushing 24 so that when the door 32 is closed and latched
there will be full support of the pipe and the tool joint. Thus,
for each different bushing 24 there is a different door 32, each
door having an internal surface configuration that when the door is
closed and latched it will, as shown in FIG. 3, form a symmetrical
central opening. Consequently, with each bushing there will be a
different door, and pairs of these two parts will be provided so
that any selected size of pipe and type of tool joint can be
handled effectively with the same elevator body.
Referring to FIG. 4, an improved means of latching and unlatching
the elevator door is shown. FIG. 4 is a front view of the elevator
and door 32, showing door handle 42. A latch arm 44 is adapted, in
one position, to extend over a portion 46 of the door. In that
position of the latch 44 the door cannot be opened. There is a part
48 of the latch 44 which can be grasped manually to pull it in a
clockwise rotation around shaft 50 to open the latch of the door
and permit the door to open.
Shaft 50 is journaled in the elevator body 10 in a horizontal
position, running from the front to the back of the elevator, as
shown in FIG. 3. On the back end of the shaft 50 is an operating
arm 52 which is shown more clearly in FIG. 5. The arm 52 depends
downwardly from shaft 50 and is connected through a clevis 54 to a
piston rod 56 which is part of a pressure fluid cylinder 58.
Cylinder 58 is supported at a pivot 60 attached to the back of the
elevator body.
By operation of the piston (not shown) in cylinder 58 so that, for
example, the piston rod 56 moves to the left, the arm 52 will
rotate the shaft in a clockwise direction viewed from the front and
will carry with it the latching arm 44 which, as it turns, will
free the latching portion 46 so that the door 32 can be opened.
Cylinder 58 can be supplied by pressure fluid through a small
diameter hose (not shown) which is mounted on a reel (not shown) in
the derrick, such that as the elevator moves up or down the hose
will be connected or a hose may loop from an upper portion in the
derrick and connect with the elevator, the loop changing elevations
as the elevator is moved up and down. By means of a fluid control
valve (not shown) the door can be unlatched automatically and
remotely using pressure fluid.
When a stand of pipe is being lowered to and is jointed to the pipe
standing in the rotary table, as when the tool joint is made up,
the pipe is lifted, freeing the weight from the elevator sitting on
the rotary table. The door of the elevator may then be unlatched
manually or hydraulically using the parts 50 through 60 described
above. The elevator may then be pulled toward the back by hydraulic
means so that it will slide along the rails 62 to a position at the
side of the rotary table. All of this is explained in the U.S. Pat.
No. 3,063,509. As the elevator door is unlatched and is pulled to
the back, movement of the pipe out of the opening 16 will cause the
door to open into the position of FIG. 1.
In FIG. 4 is shown a view of the elevator with a base portion 64
which is bolted by means of bolts 66 to the bottom surface of the
elevator body 10. This case portion 64 has opposed rails 68, one on
each side which are adapted to fit on the sloping surfaces 70 of
two spaced apart tracks 62. One portion of each of the tracks 62 is
supported on the rotary table and there are corresponding tracks
(not shown), but fully described in U.S. Pat. No. 3,063,509) which
are co-linear with those on the rotary table and extend to the back
of the rotary table. The elevator can be pulled back from the
rotary table by hydraulic means (not shown) attached to a bail 72
(see FIG. 5) to permit the pipe to be lowered, and the elevator
then supporting the pipe will rest on tracks on the rotary
table.
The two rail portions 68 are separated, as shown by dashed line in
FIG. 3, by a space in which is placed a rotatable locking member 74
(see also FIG. 6). Each locking member 74 is retained in place and
rotated around a pin 76. Each locking member 74 has a portion 74A
which extends towards body hook portion 14. Leaf springs 78 held
against body 10 by bolts 66 serve to rotate the locking members 74
so that the portions 74A extend toward hook portions 14 except when
surface 74C engages surfaces 70 of tracks 62. When the elevator is
sitting on tracks 62, the portions 74A of the locking member 74 are
withdrawn. When a bail 82 is received under hooks 14, the diameter
of the bail is greater than the opening between the hook 14 and the
locking member portions 74A, consequently there is no way for the
bail to be removed from its position under the hook 14 so long as
the locking members 74 are in their normal position.
Tracks 62 have sloping surfaces 70 shown in FIG. 4 and in FIG. 6.
When the elevator is lowered so that the rails 68 rest on the
tracks 62, then the locking member 74 rotates to the positions
shown in dashed outline in FIG. 6. This permits a full opening
under the hook 14 for the bail 82 to be lowered to a position along
the outside surfaces of the tracks 62. The bail is shown in dashed
outline 82' when the elevator is lowered onto tracks 62 and the
bails have slipped out of the hooks 14 and are resting outside of
tracks 62. In this position the elevator is free of the bails and
can be moved along the tracks either to or from the position over
the rotary table.
The elevators as illustrated and described in U.S. Pat. No.
3,063,509 are adapted to be used only in the complete system in
which the elevators are positioned on tracks to unlatch the hooks
from the bails. An important improvement encompassed in this
disclosure is a means whereby a single elevator body 10 may be
employed to perform the normal elevator function using a single
elevator to run pipe into and out of a hole. The elevator adapted
for single elevator use is best illustrated in FIG. 2. Here are
elevator base 84 of relatively flat construction is secured to the
elevator body 10 by means of bolts 86. The outer end of the base 84
has slots 88 (see FIG. 1) which receive a bail retainer length 90.
In like manner the body hook portions 14 include slots 92 (see the
right portion of FIGS. 1 and 2) which receive the upper end of the
bail retainers 90. Pins 94 extend through the base 84 in the lower
end of bail retainer 90 and, in like manner, pins 96 extend through
the hook 14 in the upper end of bail retainers 90 to maintain the
retainers in position. Keys as illustrated may be utilized to
maintain the pins 94 and 96 in position.
The arrangement for retaining bails is shown in FIG. 2 with the
removable base 84, means that the elevator body as illustrated
herein may be employed for adapting the elevator to a normal usage
wherein it is maintained in connection with the bails for running
pipe in and out of the hole when only one elevator is employed and
when the tracks as illustrated in FIGS. 3 and 4 are not utilized,
it can be seen that the base portion 64 of FIGS. 3 and 4 is
interchangeable with the base portion 84 of FIGS. 1 and 2 to adapt
the elevator body 10 to either its normal single elevator operation
or to the dual automatic elevator operation of the system described
in U.S. Pat. No. 3,063,509. While in FIG. 2 the base 84 is shown
supported to the body with bolts 86 it can be seen that if desired
the base may be welded to the body 98.
When the universal elevator body 10 is employed according to the
teachings of this invention having the replaceable bushings 24 and
replaceable bases 64 and 84 with the replaceable doors 32 it can be
seen that a manufacturer can materially reduce the cost of
providing elevators to meet different requirements including
different sizes of drilling pipe and different tool joint end
configurations. This adaptability can result in greater savings to
manufacturers, suppliers, and users of elevators which has not
heretofore been possible.
When drilling pipe is removed from a well hole to change the bit or
for any purpose the drill pipe is stacked and an operator standing
in the upper portion of the derrick guides the pipe in the stacked
position and releases the elevator therefrom. This is the case
whether the elevator is used in the normal manner or in the dual
automatic system of U.S. Pat. No. 3,063,509. When the pipe is to be
rerun back into the hole a man must stand at the upper portion of
the derrick and when the elevator is raised into position to grasp
a new length of pipe to be lowered in the hole, he must guide the
elevator into engagement with a length of drill pipe. When the
elevator is moved onto a pipe the finger 36 engages the pipe to
close the door so that it automatically latches. However, to
effectively engage the pipe the angle of tilt of the elevator is
important. If the elevator is constructed such that with the door
closed it has the center of gravity directly beneath the elevator,
when the elevator door 32 is opened the center gravity shifts and
there is a tendency for the elevator to tilt downwardly by the
weight of the door. This can cause the elevator to improperly
function when the operator brings the elevator manually into
position to engage and clamp around the upper end of a vertical
length drill pipe. FIGS. 3 and 5 illustrate a means of compensating
for the tilt which takes place due to the open door 32 of an
elevator.
As shown in FIG. 5, there is a vertical bar 100 which is attached
to the base 64 of the elevator by means of a bolt 102. A weight 104
has a central opening 106 adapted to slide on the bar 100. The
weight can be fastened aat any desired point by means of a lock
bolt 108.
When the elevator is supported in the bails under the hooks 14, the
additional weight of 104 supported at the back of the bail will
cause the elevator to tilt to a selected angle from the vertical.
This angle of tilt can be adjusted to match the angle of a stand of
pipe which is to be inserted into the elevator and to compensate
for the weight of door 32. Since the central bore and the bushings
are adapted to fit fairly snugly to the sides of the pipe, the
ability to tilt the angle of the elevator to suit the angle of the
axis of the pipe makes it possible for the pipe to be inserted into
the elevator and the door to be closed with much less effort than
if the axis of the elevator is at a different angle than the axis
of the pipe. Consequently, the counterweight 104 is important in
the fast and efficient operation of the elevator in clamping to a
stand of pipe.
Weight 104 includes portions 104A and 104B which may be added or
removed to vary the total weight used to provide the desired tilt
to the suspended elevator. Thus the tilt of the suspended elevator
may be selected by: (a) varying the angle of bar 100 relative to
the elevator body: (b) varying the elevational position of weight
104 on bar 100; and (c) varying the amount of weight by adding or
removing portions 104A and 104B.
While the invention has been described with a certain degree of
particularity it is manifest that many changes may be made in the
details of construction and the arrangement of components and
details of operation. It is understood that the invention is not to
be limited to the specific language used or the specific
embodiments set forth herein by way of exemplification of the
invention, but the invention is to be limited only by the scope of
the attached claim or claims, including the full range of
equivalence to which each element or step thereof is entitled.
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