U.S. patent application number 11/371383 was filed with the patent office on 2007-03-29 for pipe gripping ram.
Invention is credited to Gerald Lesko.
Application Number | 20070068669 11/371383 |
Document ID | / |
Family ID | 37890019 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070068669 |
Kind Code |
A1 |
Lesko; Gerald |
March 29, 2007 |
Pipe gripping ram
Abstract
A ram is provided for use in the live and dead heads of an iron
roughneck. The ram grips sections of pipe as connections are made
or broken between the pipe sections. The ram includes a cylinder
block having a bore and a fixed piston centered therein forming an
annulus. An annular piston slides in and out of the cylinder block
in the annulus. A tong mounted on the end of the end of the annular
piston for gripping pipe includes a tong shoe and a tong die within
the shoe. The tong die is capable of moving side-to-side within the
shoe to self-center itself when gripping pipe. Pressurized gas or
hydraulic fluid systems can be used to extend and retract the
annular piston within the cylinder block.
Inventors: |
Lesko; Gerald; (Alberta,
CA) |
Correspondence
Address: |
DINSMORE & SHOHL, LLP
1900 CHEMED CENTER
255 EAST FIFTH STREET
CINCINNATI
OH
45202
US
|
Family ID: |
37890019 |
Appl. No.: |
11/371383 |
Filed: |
March 9, 2006 |
Current U.S.
Class: |
166/77.51 ;
166/85.1 |
Current CPC
Class: |
E21B 19/163
20130101 |
Class at
Publication: |
166/077.51 ;
166/085.1 |
International
Class: |
E21B 19/18 20060101
E21B019/18 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 23, 2005 |
CA |
2,520,927 |
Claims
1. A pipe gripping ram, comprising: a) a cylinder block having
first and second ends and a bore extending therebetween along a
longitudinal axis, said bore forming an interior cylinder wall
within said cylinder block; b) an end cap operatively attached to
the first end of said cylinder block thereby enclosing said bore at
said first end; c) a fixed piston having a head and a neck disposed
within said bore, said head larger in diameter than said neck, said
neck operatively attached to said end cap whereby said fixed piston
head is longitudinally aligned with said longitudinal axis and
thereby forming a substantially uniform annulus between said fixed
piston head and said interior cylinder wall, said annulus extending
from the second end of said cylinder block at least partially along
said bore towards said end cap; d) an annular piston having first
and second ends, the first end of said annular piston being open
and adapted to slidably couple with said fixed piston whereby said
annular piston is capable of linear reciprocal motion along said
annulus, the second end of said annular piston being closed and
forming a first chamber when said annular piston is slidably
coupled with said fixed piston, the first end of said annular
piston further comprising a stop to prevent said annular piston
from sliding off said fixed piston, the combination of said fixed
piston and the first end of said annular piston forming a second
annular chamber; e) a pipe gripping tong operatively attached to
the second end of said annular piston; and f) means for moving said
annular piston in a linear reciprocal motion within said annular
bore.
2. The ram as set forth in claim 1 wherein said bore is
substantially cylindrical.
3. The ram as set forth in claim 1 wherein said means for moving
said annular piston comprises a hydraulic fluid system.
4. The ram as set forth in claim 1 wherein said means for moving
said annular piston comprises a pneumatic air system.
5. The ram as set forth in claim 3 further comprising a first
passageway disposed within said fixed piston providing
communication to said first chamber for hydraulic fluid to enter
said first chamber and move the second end of said annular piston
away from said cylinder block.
6. The ram as set forth in claim 5 further comprising a second
passageway disposed within said fixed piston providing
communication to said second annular chamber for hydraulic fluid to
enter said second annular chamber and move the second end of said
annular piston towards said cylinder block.
7. The ram as set forth in claim 4 further comprising a first
passageway disposed within said fixed piston providing
communication to said first chamber for pressurized gas to enter
said first chamber and move the second end of said annular piston
away from said cylinder block.
8. The ram as set forth in claim 7 further comprising a second
passageway disposed within said fixed piston providing
communication to said second annular chamber for pressurized gas to
enter said second annular chamber and move the second end of said
annular piston towards said cylinder block.
9. The ram as set forth in claim 1 wherein said tong further
comprises a tong shoe and tong die for gripping a pipe disposed
within said tong shoe, said tong die capable of lateral movement
within said tong shoe.
10. The ram as set forth in claim 6 further comprising a swash
plate mechanism for controlling the direction of hydraulic fluid
into and out of said first and second passageways.
11. The ram as set forth in claim 8 further comprising a swash
plate mechanism for controlling the direction of pressurized air or
gas into or out of said first and second passageways.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of rams for
gripping drilling pipe. More specifically, the present invention
relates to pipe gripping rams on automated iron roughnecks used on
drilling rigs.
BACKGROUND OF THE INVENTION
[0002] Automated iron roughnecks are used on drilling rigs to
perform the often dangerous tasks of making and breaking joints
between sections of drilling pipe. An iron roughneck usually has
two sets of jaws with pipe gripping tongs positioned in a vertical
configuration, one on top of the other. The lower set of jaws or
"dead head" holds the box end of the section of pipe connected to
the drill string. The upper set of jaws or "live head" grasps the
pin end of the section of pipe being joined to or removed from the
drill string. The dead head tongs hold the drill string steady
while the live head tongs turn the pin end of the pipe section
clockwise to make a pipe connection or counter-clockwise to break a
pipe connection. Depending on the diameter of the pipe used in the
drill string and the amount of force used in turning the drill
string to drill a hole, it may take several hundreds of foot-pounds
of torque to break a connection between sections of pipe.
[0003] It is, therefore, desirable to have a pipe gripping ram used
in the dead head and live head tongs of an iron roughneck that is
capable exerting the force required to make and break joints
between sections of drilling pipe.
SUMMARY OF THE INVENTION
[0004] In accordance with an embodiment of the present invention, a
ram is provided for use with a live head or dead head tong to grip
sections of drilling pipe. Each live head or dead head tong has two
rams facing towards each other. When a pipe is grasped by the live
head or dead head, the rams extend tong dies towards the pipe until
contact is made with sufficient force to keep the tong dies from
slipping on the pipe when a joint is made or broken between
sections of pipe.
[0005] Each ram comprises a cylinder block having a horizontal bore
with a longitudinal axis extending through the block. For ease of
manufacturing, the bore can be cylindrical although it should
obvious to those skilled in the art that other cross-sectional
shapes (such as elliptical or rectangular) can be used.
[0006] One end of the block has an end cap enclosing the bore from
that end. A fixed piston is disposed within the bore and is
attached to the end cap. The fixed piston has a head and a neck.
The head is larger in diameter than the neck. The neck end of the
fixed piston is attached to the end cap such that the piston head
is centered within the bore to form a substantially uniform annulus
between the fixed piston head and the interior cylinder wall.
[0007] A first end of an annular piston slidably couples with the
fixed piston such that the annular piston is capable of linear
reciprocal motion along the annulus. The second end of the annular
piston has a pipe gripping tong attached to it thereby forming a
first chamber within the annular piston between its second end and
the fixed piston. An annular ring or stop is attached to the first
end of the annular piston and slides along the neck of the fixed
piston. The combination of the fixed piston head, the annular
piston and the annular ring forms a second annular chamber disposed
about the fixed piston neck. The transition from the neck to the
head on the fixed piston acts as a stop for the annular ring and
keeps the annular piston from sliding out of the cylinder block as
the annular ring contacts the head of the fixed piston.
[0008] To extend the annular piston out from the cylinder block so
that the pipe tong contacts the pipe, and to retract the annular
piston into the cylinder block to release the pipe from the tongs,
a pressurized hydraulic fluid system can be used.
[0009] A first passageway disposed within the fixed piston from the
end cap side of the fixed piston provides communication to the
first chamber. Hydraulic fluid entering the first passageway will
enter into the first chamber extending the annular piston out from
the cylinder block. A second passageway also disposed within the
fixed piston provides communication to the second annular chamber.
Hydraulic fluid entering the second passageway will enter into the
second annular chamber and push the annular piston into the
cylinder block. When the annular piston is extended, the second
passageway acts as an exit pathway for any fluid in the second
annular chamber as the annular piston moves outward. When the
annular piston is retracted, the first passageway acts as an exit
pathway for any fluid in the first chamber as the annular piston
moves inward towards the cylinder block. A conventional hydraulic
swash-plate mechanism, as well known to those skilled in the art,
can be used in the control of hydraulic fluid entering and exiting
the fluid passageways. In an alternate embodiment, a pneumatic air
or gas system can be used in place of hydraulics for moving the
annular piston.
[0010] The pipe-gripping tong mounted on the second end of the
annular piston comprises a tong shoe and a tong die mounted within
the shoe. The tong die has two surfaces with teeth for gripping a
pipe. The two surfaces are at an angle to one another to form a
shallow v-shaped groove. The shoe has a partial circular opening
that allows the tong die to slide into the shoe and be secured by
retainer ears mounted on top and bottom of the tong shoe. The tong
shoe opening is slightly wider than the tong die such that the tong
die has a small amount of side-to-side lateral movement within the
shoe thereby allowing the tong die to self-center on a pipe in the
event that the pipe is not exactly centered within the jaws of the
live head or dead head tongs.
[0011] In operation, a pair of rams can be used in each of the live
and dead heads on an iron roughneck. Each pair of rams face each
other in an opposing manner. When a section of pipe is to be added
to a drill string, the drill string is first supported by the slips
in the rotary table of the drilling rig. The iron roughneck is then
advanced towards the drill string and the dead head rams clamp the
box end of the exposed pipe section. A new section of pipe is
lowered into position above the drill string where the pin end of
the new section is inserted into the exposed box end. The live head
rotates counterclockwise so that its rams can clamp the pin end of
the new section. The live head then rotates clockwise to torque the
connection between the pipe sections. When a connection between
sections of pipe is to be broken, the process is reversed.
[0012] Broadly stated, one embodiment of the present invention
involves a pipe gripping ram which comprises: a cylinder block
having first and second ends and a bore extending therebetween
along a longitudinal axis, said bore forming an interior cylinder
wall within said cylinder block; an end cap operatively attached to
the first end of said cylinder block thereby enclosing said bore at
said first end; a fixed piston having a head and a neck disposed
within said bore, said head larger in diameter than said neck, said
neck operatively attached to said end cap whereby said fixed piston
head is longitudinally aligned with said longitudinal axis and
thereby forming a substantially uniform annulus between said fixed
piston head and said interior cylinder wall, said annulus extending
from the second end of said cylinder block at least partially along
said bore towards said end cap; an annular piston having first and
second ends, the first end of said annular piston being open and
adapted to slidably couple with said fixed piston whereby said
annular piston is capable of linear reciprocal motion along said
annular bore, the second end of said annular piston being closed
and forming a first chamber when said annular piston is slidably
coupled with said fixed piston, the first end of said annular
piston further comprising a stop to prevent said annular piston
from sliding off said fixed piston, the combination of said fixed
piston and the first end of said annular piston forming a second
annular chamber; a pipe gripping tong operatively attached to the
second end of said annular piston; and means for moving said
annular piston in a linear reciprocal motion within said annular
bore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a front perspective view depicting a ram in
accordance with one embodiment of the present invention, wherein
the annular piston extended.
[0014] FIG. 2 is a rear perspective view depicting the ram in FIG.
1, wherein the annular piston extended.
[0015] FIG. 3a is a side cross-sectional view depicting the ram of
FIGS. 1-2 and taken along section lines A-A in FIG. 2, where the
annular piston is extended.
[0016] FIG. 3b is a side cross-sectional view depicting the ram of
FIGS. 1-2 and taken along section lines A-A in FIG. 2, wherein the
annular piston is retracted.
[0017] FIG. 4 is a perspective view depicting an iron roughneck
having a ram in accordance with one embodiment of the present
invention, wherein the iron roughneck is preparing to grip a
section of pipe.
[0018] FIG. 5 is perspective view depicting the iron roughneck of
FIG. 4 wherein the iron roughneck is joining two sections of
pipe.
DETAILED DESCRIPTION OF EMBODIMENTS
[0019] Referring to FIGS. 1 and 2, a representative embodiment of
the present invention is shown. Ram 10 comprises a cylinder block
22, end cap 24, annular piston 20 and tong shoe 12. End cap 24 is
fastened to cylinder block 22 by cap screws passing through bolt
holes 31. Annular piston 20 slides in and out of bore 23 and
cylinder block 22. Tong shoe 12 has a circular opening 41 to
receive tong die 13. Tong die retainers 16 are fastened to the top
and bottom of tong die 13 to keep it in place within shoe 12. Tong
die 13 comprises a pair of die faces 14. Die faces 14 form a shell
v-shaped groove for receiving a section of pipe to grip.
[0020] Tong shoe 12 further comprises grooves 19 to receive
retainer ear 17 of retainers 16. Groove 19 is slightly wider than
ear 17 so as to allow tong die 13 to move laterally side-to-side
within opening 41. A combination of shallow v-shaped groove faces
14 and the side-to-side movement of tong die 13 allows tong die 13
to self-center on a section of pipe when gripping it in the event
that the pipe is not centered within the live head or dead head
jaws of an iron roughneck.
[0021] Referring to FIGS. 3a and 3b, side cross-sectional views of
a ram 10 in accordance with one embodiment of the present invention
are shown. Fixed piston 26 is attached to end cap 24 by cap screws
25. Fixed piston 26 comprises neck 37 and head 35. Head 35 is shown
to be larger in diameter than neck 37. A portion of neck 37 extends
through opening 29 to allow the end of neck 37 to be flush with end
cap 24. Annulus 27 bore is formed between the cylinder wall of bore
23 and fixed piston 26.
[0022] Tong shoe 12 is bolted to annular piston 20 with cap screw
15. Annular piston 20 slides into the annulus 27 between fixed
piston 26 and the cylinder wall of bore 23. Seal 44 and ring 46 in
a groove disposed around piston head 35, in combination with wiper
ring 42 disposed within a groove around bore 23, provide a
liquid-tight seal around annular piston 20. Wear band 40 is
disposed about another groove around piston head 35. Piston spacer
34 is situated on fixed piston 26 where neck 37 adjoins piston head
35. Piston spacer 34 further comprises an annular groove 36. Piston
end ring 32 is fastened to annular piston 20 with cap screws 33.
Wear band 48, seal 50 and ring 52 dispose within grooves on end
ring 32 provide a liquid-tight seal between end ring 32 and piston
neck 37.
[0023] Disposed within fixed piston 26 are two passageways.
Passageway 30 provides communication to chamber 21. Chamber 21 is
located between piston head 35 and annular piston 20. Passageway 28
provides communication to annular chamber 38 located between end
ring 32 and piston spacer 34.
[0024] Referring to FIG. 3a, pressurized hydraulic fluid entering
passageway 30 can enter chamber 21 and push annular piston 20
outward from cylinder block 22. Any fluid in annular chamber 38 is
forced out through annulus 36 and passageway 28 until end ring 32
contacts piston spacer 34. The force exerted by tong die 13 as
annular piston 28 is extended is a function of the pressure of the
hydraulic fluid, the diameter of annular piston 20 and the size of
die faces 14 which can be easily determined by those skilled in the
art.
[0025] Referring to FIG. 3b, pressurized hydraulic fluid entering
passageway 28, can enter annular chamber 38 through annulus 36 and
push end ring 32 towards end cap 24. Any fluid in chamber 21 is
forced out through passageway 30 until annular piston 20 contacts
piston head 35. A hydraulic swash space plate (not shown), as well
known to those skilled in the art, can be used to control the flow
of pressurized hydraulic fluid into and out of passageways 28 and
30. It should be obvious to those skilled in the art that a ram in
accordance with the present invention may be operated with
pressurized air or gas instead of pressurized hydraulic fluid. The
use of a pressurized hydraulic fluid system or pneumatics is
desirable for use with a ram in accordance with the present
invention given the combustible and explosive nature of the
substances obtained from oil and gas wells.
[0026] Referring to FIGS. 4 and 5, a ram in accordance with the
present invention is shown on iron roughneck 60 situated on a
drilling rig platform. Iron roughneck 60 comprises live head 62 and
dead head 64. Live head 62 and dead head 64 each have a pair of
rams 10. In FIG. 4, pipe 66 is being connected to pipe 68. The rams
10 in dead head 64 grasp pipe 68 to hold it in place which is
further supported by slips 70 in rotary table 72. Pipe 66 is being
lowered to make a connection with pipe 68.
[0027] In FIG. 5, live head 62 has rotated to grasp pipe 66 with
rams 10. Once gripped, live head 62 rotates clockwise to tighten
the threaded connection between pipes 66 and 68. To break the
connection between the pipes, the procedure is reversed.
[0028] Although embodiments of the present invention have been
shown and described, it will be appreciated by those skilled in the
art that various changes and modifications might be made without
departing from the scope of the invention. The terms and
expressions used in the preceding specification have been used
herein as terms of description and not of limitation, and there is
no intention in the use of such terms and expressions of excluding
equivalents of the features shown and described or portions
thereof, it being recognized that the scope of the invention is
defined and limited only by the claims that follow.
* * * * *