U.S. patent number 3,920,070 [Application Number 05/521,473] was granted by the patent office on 1975-11-18 for pipe cutter.
Invention is credited to Mack Goins.
United States Patent |
3,920,070 |
Goins |
November 18, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Pipe cutter
Abstract
Disclosed is a pipe cutter including annular, axially aligned,
gear, grip and cutter sections and a central shaft within the
sections. The shaft is geared to the gear section for rotation in
response to axial upward movement of the shaft relative to the gear
section. The grip section carries pivoted jaws which are cammed
outwardly by an enlarged diameter portion of the shaft in response
to axial upward movement of the shaft relative to the gear, grip
and cutter sections. The cutter section is journalled to the lower
end of the grip section and carries a plurality of pivoted cutting
blades movable laterally outwardly into engagement with the inner
wall of the pipe casing in response to axial upward movement of the
shaft. The cutter section is also splined to the shaft for rotation
therewith. A cylinder is carried at the upper end of the gear
section and the upper end of the shaft carries a piston in the
cylinder. Upward movement of the piston within the cylinder by
ignition of a power charge cams the jaws laterally outwardly to
grip the interior pipe wall and causes rotation of the shaft
relative to the gear section. Upward movement of the shaft also
cams the cutting blades laterally outwardly and rotates such blades
to cut the pipe. At the end of the upward stroke of the shaft, a
reduced diameter shaft portion backs the jaws enabling such jaws to
pivot laterally inwardly to release the cutter from the pipe wall.
The lower end of the shaft is also located above the cutter blades
enabling the blades to retract within the cutter section.
Inventors: |
Goins; Mack (Lake Charles,
LA) |
Family
ID: |
24076865 |
Appl.
No.: |
05/521,473 |
Filed: |
November 6, 1974 |
Current U.S.
Class: |
166/55.8;
166/298 |
Current CPC
Class: |
E21B
29/00 (20130101) |
Current International
Class: |
E21B
29/00 (20060101); E21B 029/00 () |
Field of
Search: |
;166/55,55.1,55.2,55.3,55.6,55.7,55.8,298 ;30/92,103 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: LeBlanc & Shur
Claims
What is claimed and desired to be secured by United States letters
patent is:
1. Apparatus for cutting pipe internally comprising:
an elongated body adapted to be received within the pipe;
an elongated element within said body and axially movable relative
thereto;
means carried by said body movable from a retracted position to a
laterally extended position for gripping the interior wall of the
pipe;
a cutter carried by said body for rotational movement about the
axis thereof and movable from a retracted position to a laterally
extended position for cutting engagement with the pipe wall;
first means carried by said element and engageable with said
gripping means for displacing said gripping means from its
retracted position to its laterally extended position in response
to displacement of said element relative to said body in one axial
direction;
second means carried by said element and engageable with said
cutter for displacing said cutter from its retracted position to
its laterally extended position in response to displacement of said
element relative to said body in said one axial direction;
means cooperable between said body and said elements for displacing
said element in said one axial direction relative to said body;
and
means cooperable between said body and said element for rotating
said cutter relative to said body in response to displacement of
said element relative to said body in said one axial direction.
2. Apparatus according to claim 1 wherein said element comprises a
shaft, said first displacing means including a cam carried by said
shaft, said gripping means having a cam follower engageable with
said cam, said gripping means including a jaw pivotally coupled to
said body, said cam being engageable with said follower in response
to displacement of said element in said one axial direction to
pivot said jaw laterally outwardly into engagement with the
interior pipe wall, said second displacing means including a cam
carried by said element, said cutter having a cam follower and
engageable with said cam.
3. Apparatus according to claim 1 wherein said body includes an
annular sleeve having a plurality of circumferentially spaced
openings thereabout, and a plurality of jaws carried by said sleeve
and respectively disposed in said openings for movement between
extended and retracted positions.
4. Apparatus according to claim 1 wherein said axial displacing
means includes a cylinder forming part of said body and a piston
within said cylinder forming part of said element.
5. Apparatus according to claim 1 wherein said element is axially
movable in said one axial direction relative to said body from a
first axial position, with said gripping means and said cutter
retracted, to second and third axial positions, said element in
said second position locating said first and second displacing
means in respective engagement with said gripping means and said
cutter to maintain said gripping means and said cutter in laterally
extended positions, said element in said third position locating
said first and second displacing means relative to the respective
gripping means and cutter to enable said gripping means and said
cutter to return to their respective retracted positions.
6. Apparatus according to claim 1 wherein said body comprises a
sleeve and said element comprises a shaft, said rotating means
including cooperable gears carried by said shaft and said
sleeve.
7. Apparatus according to claim 1 wherein said second displacing
means includes a cam carried by said element, said cutter having a
cam follower in engagement with said cam.
8. Apparatus according to claim 7 wherein said cutter includes a
bracket pivotally carried by said body and carrying a cutting edge
adjacent an end thereof, said cam being engageable with said
follower in response to displacement of said element in said one
axial direction to pivot said bracket laterally outwardly into
engagement with the interior pipe wall.
9. Apparatus according to claim 1 wherein said body comprises a
sleeve and said element comprises a shaft coaxially disposed within
said sleeve, said sleeve having a plurality of circumferentially
spaced openings thereabout, said gripping means including a
plurality of jaws carried by said sleeve and respectively disposed
in said openings, a second sleeve coupled to the first mentioned
sleeve for rotation relative thereto and having a plurality of
circumferentially spaced openings thereabout, said cutter including
a plurality of cutting tools carried by said second sleeve and
respectively disposed in the openings through said second sleeve,
said first and second displacing means including respective first
and second cams carried by said shaft and engageable with the
respective jaws and cutting tools.
10. Apparatus according to claim 9 wherein said axial displacing
means includes a cylinder carried by said sleeve and a piston
within said cylinder carried by said shaft, said shaft being
axially movable in said one direction relative to said first
mentioned sleeve from a first axial position, with said jaws and
said cutting tools retracted, to second and third axial positions,
said shaft in said second position locating said first and second
displacing means in respective engagement with said jaws and said
cutting tools to maintain said jaws and said tools in laterally
extended positions, said shaft in said third position locating said
first and second displacing means relative to said jaws and said
cutting tools to enable said jaws and said tools to return to their
respective retracted positions.
11. Apparatus according to claim 1 wherein said first displacing
means includes a cam carried by said element, said gripping means
having a cam follower engageable with said cam.
12. Apparatus according to claim 11 wherein said gripping means
includes a jaw pivotally coupled to said body, said cam being
engageable with said follower in response to displacement of said
element in said one axial direction to pivot said jaw laterally
outwardly into engagement with the interior pipe wall.
13. Apparatus according to claim 12 wherein said jaw has a
longitudinally extending gripping surface, and means mounting said
jaw for translational movement in a laterally outward direction to
locate the gripping surface of said jaw in substantially parallel
relation to the long axis of said body.
Description
The present invention relates to apparatus and methods for cutting
pipe and particularly relates to apparatus and methods for cutting
pipe internally from a remote position, for example cutting well
casing pipe.
Many and various prior apparatus and methods have been proposed for
cutting pipe internally and a great deal of interest today is being
focused on the recovery of pipe from unused or exhausted wells in
view of the present shortage and high cost of pipe. Such prior
methods have included using a dynamite cutter for cutting the pipe
in the well. However, this method has a number of disadvantages
including the possible fracture of geological formations and other
adverse environmental effects. Cutters using a chemical action to
cut pipe into sections have been proposed and utilized but these
are effective only about one-half the time. Mechanical type cutters
carried by an assembled string of pipe have also been used. These,
however, involve a great deal of time and expense since the pipe
must first be assembled to the required length and later
disassembled after cutting the pipe casing. Pipe cutters hung
within the well casing from cables have also been proposed.
Examples of these types of pipe cutters are disclosed in U.S. Pat.
Nos. 2,622,679 and 1,643,709. In the former patent, jaws are
carried by the cutter for engagement with the inner wall of the
pipe in response to a slight upward pull on the cable supporting
the cutter in the well casing. A reciprocating action provided the
cable and a weight forming part of the cutter is necessary to
gradually laterally extend the cutting teeth into cutting
engagement with the pipe casing. The latter mentioned patent also
utilizes an upward pull on the cable suspending the cutter in the
pipe casing to rotate the cutter head. The manner in which these
cutters are set in the pipe casing and by which the cutter blades
are rotated requires considerable time and effort to effect the
cut. Additionally, such mechanisms are cumbersome, are comprised of
a large number of parts, and are therefore expensive to
manufacture.
The present invention provides a pipe cutter which eliminates or
minimizes the foregoing and other problems associated with prior
pipe cutting apparatus and methods and provides novel and improved
apparatus and methods for cutting pipe internally having various
advantages in construction, mode of operation and result in
comparison with such prior pipe cutting apparatus and methods.
Particularly, the present invention provides a pipe cutter which
engages the pipe wall to fix the cutter within the pipe and cuts
the pipe in response to a single axial stroke of a shaft in one
direction. More particularly, the pipe cutter hereof includes
annular, axially aligned, gear, grip and cutter sections and in
which a coaxial shaft is received. The upper end of the shaft
carries a piston disposed within a cylinder located at the upper
end of the gear section, the cylinder having a hanger support at
its upper end whereby the pipe cutter can be raised from and
lowered into a well casing by a cable. Portions of the shaft and
gear sections are geared one to the other whereby the shaft rotates
relative to the gear section after the cutter is fixed to the well
casing and in response to upward axial displacement of the shaft
relative to the gear, grip and cutter sections. To fix the cutter
to the interior wall of the pipe, a plurality of circumferentially
spaced pivoted jaws are carried by the grip section and which jaws
pivot in response to axially upward movement of the shaft from
retracted positions within the cylindrical confines of the grip
section radially outwardly to engage the interior wall of the pipe
section. The cutter section is coupled to the lower end of the grip
section through a bearing whereby the cutter section is rotatable
relative to the slip and gear sections. The cutter section and a
portion of the shaft extending through the cutter section are
splined one to the other such that the rotation of the shaft causes
rotation of the cutter section. A plurality of cutter blades are
pivotally carried by the cutter section and are cammed outwardly
from a retracted position, in response to upward movement of the
shaft into cutting engagement with the inner walls of the pipe.
When the pipe cutter is lowered into the well casing, and located
at the desired depth, a power charge is ignited, the gas from which
expands to drive the piston upwardly relative to the cylinder.
Initial axial upward movement of the shaft causes an enlarged
diameter portion of the shaft in the grip section to cam the jaws
outwardly into engagement with the inner walls of the pipe. Upward
movement of the shaft relative to the gear section also causes
relative rotation therebetween which, when the jaws engage the
pipe, causes rotation of the shaft relative to the fixed gear
section. The shaft also rotates the cutter section through its
splined engagement therewith. As the shaft rotates and is displaced
upwardly, the tapered lower end of the shaft cams the cutter blades
into engagement with the wall of the pipe and continued rotation of
the cutting section and upward movement of the shaft causes the
cutting edges to bear against the pipe wall with increasing
pressure thereby cutting through the pipe. When the pipe is finally
cut through, the enlarged diameter portion of the shaft in the grip
section is displaced upwardly past the jaws enabling the jaws to
pivot inwardly into their retracted positions thereby releasing the
pipe cutter from engagement with the pipe. After the cut is
completed, the lower end of the shaft is also displaced upwardly
past the cutter blades whereupon the blades are spring retracted
into their initial retracted position. After the pipe has been cut,
the pipe cutter is thus returned to its cable suspended condition
within the well casing and can be hauled upwardly out of the pipe
by hauling in the cable and subsequently charged for making another
cut.
Accordingly, it is the primary object of the present invention to
provide a novel and improved apparatus and methods for internally
cutting pipe.
It is another object of the present invention to provide novel and
improved apparatus and methods for internally cutting pipe wherein
the pipe cutter is suspended within a well casing by a cable.
It is still another object of the present invention to provide
novel and improved apparatus and methods for internally cutting
pipe in which the cutter substantially simultaneously grips and
cuts the pipe in response to the movement of a single operative
element.
It is a further object of the present invention to provide novel
and improved apparatus and methods for cutting pipe internally and
wherein the pipe cutter is formed of a relatively small number of
inexpensive parts and which can be readily and easily assembled and
utilized.
These and further objects and advantages of the present invention
will become more apparent upon reference to the following
specification, appended claims and drawings wherein:
FIG. 1 is a fragmentary side elevational view of a pipe cutter
constructed in accordance with the present invention and
illustrated as disposed in a well casing;
FIGS. 2, 3 and 4 are fragmentary enlarged vertical cross sectional
views of respective upper, intermediate and lower portions of the
pipe cutter illustrated in FIG. 1;
FIG. 2A is an enlarged fragmentary cross-sectional view of the
upper portion of the pipe cutter illustrating the power charge and
actuating wires therefor;
FIGS. 5, 6, 7, 8 and 9 are cross-sectional views taken generally
about on the corresponding numbered lines in FIGS. 3 and 4;
FIG. 10 is an enlarged fragmentary cross-sectional view of the grip
section of the pipe cutter illustrating the gripping jaws in a
retracted position; and
FIG. 11 is a fragmentary enlarged cross-sectional view of a portion
of the cutter section and illustrating the cutter blades in a
retracted position.
Referring now to the drawings, particularly to FIG. 1, there is
illustrated a well bore containing a pipe casing designated P and
which pipe casing is to be cut by the pipe cutter generally
designated 10 hereof preparatory to removing the cut casing from
the well bore. Particularly, the pipe cutter generally includes at
its upper end a cylinder section 12, a gear section 14, a grip
section 16, and a cutter section 18, all of which sections are in
axial alignment one with the other with the cylinder section
located at the top of the cutter and the cutting section located at
the bottom thereof and the gear and grip sections intermediate such
upper and lower sections. At the upper end of the cylinder section
12 there is provided a hanger support 20 for connection with a
cable 22 whereby the pipe cutter 10 can be suspended within the
casing in the well bore. The cylinder section 12 carries a piston
head 24 which is located at the upper end of a shaft 26 and which
shaft extends the length of the pipe cutter as illustrated and as
will be apparent from the ensuing description. The shaft 26 passes
through a suitable reduced diameter portion of the lower end of
cylinder 12. The lower end of cylinder 12 is screwthreaded into the
upper end of an annular sleeve 32 which forms a part of the gear
and grip sections of pipe cutter 10. Sleeve 32 is internally
threaded at 34 over a substantial portion of its length adjacent
its upper end. A portion of the length of shaft 26 within sleeve 32
and in gear section 14 is externally threaded at 36 for threaded
engagement with the internally threaded portions of sleeve 32. As
illustrated in FIG. 3, shaft 26 has a reduced diameter portion 38
below the threaded portion 36 for reasons noted hereinafter.
Referring now to FIGS. 3, 5 and 11, grip section 16 includes a
plurality of circumferentially spaced openings 39 in each of which
is disposed a jaw 40. Jaws 40 are pivotally secured about pins 42
coupled to sleeve 32. It will be appreciated that the jaws 40 are
thus circumferentially spaced about sleeve 32 and that three or
four jaws are preferred, four jaws being illustrated. Each of jaws
40 is generally T-shaped in axial cross section and has an outer
face 44 which is arcuate to conform to the arcuate or circular
section of sleeve 32 when each jaw lies in its retracted position
illustrated in FIGS. 5 and 10. The faces 44 are knurled or serrated
to enhance gripping engagement with the inner wall of pipe casing
P. Each jaw 40 includes a cam follower 50 along its inner or back
surface and which follower projects within the bore of sleeve 32.
The inner wall of sleeve 32 adjacent one end of each opening 39 is
undercut at 52 to form a stop for a finger 54 which projects from
the end of jaw 40 remote from its pivot pin 42. Consequently, from
a review of FIG. 11, it will be appreciated that each jaw 40 is
pivotal laterally outwardly about pin 42 from its illustrated
retracted position to a projected position illustrated by the
dashed lines in FIG. 5, such lateral outward movement being limited
by finger 54 in engagement against stop 52. Each pin 42 is also
received within an elongated radially extending slot 43 at the base
of the corresponding jaw 40 whereby each jaw 40 is first pivotal
outwardly about pin 42 and then pivoted about the opposite end of
the jaw and translated such that the entirety of face 44 lies flush
against the inside wall of pipe P and generally parallel to the
long axis of the cutter. Also, any suitable type of retaining
spring, not shown, may be utilized to bias each jaw 40 toward and
retain it in its retracted position.
With reference to FIGS. 3 and 11, shaft 26 has an enlarged diameter
portion 56 below the reduced diameter portion 38 and also below
jaws 40. The shoulder 58 between the reduced and enlarged diameter
portions 26 and 56, respectively, of shaft 26 forms a cam operable
against the inside surfaces or cam followers 50 of jaws 40. It will
be appreciated that upward movement of shaft 26 relative to sleeve
32 causes cam 58 to engage the inside surface of cam follower 50 to
pivot and translate jaws 40 outwardly into engagement with the
inner wall of the pipe P with the enlarged diameter portion 56
maintaining the jaws in laterally extended positions as the shaft
26 both rotates and moves axially as explained below.
The sleeve 32 of the gear and grip sections is coupled to the upper
end of cutter section 18 and which section 18 includes a cutter
sleeve 60 and a bearing 62 rotatably coupled to the lower end of
sleeve 32 whereby the cutter sleeve 60 is rotatable relative to
sleeve 32. Bearing 62 includes an axially split element externally
threaded at its lower end for connection with the internal threads
of the upper end of cutter sleeve 60. Bearing 62 is internally
grooved for rotatable engagement with a similarly grooved lower end
portion of sleeve 36 whereby bearing 62 is rotatable relative to
sleeve 36 but prevented from axial disengagement therefrom.
Referring to FIG. 4, cutter sleeve 60, immediately below the
internally threaded portion thereof which connects with bearing 62,
is provided with a hex shaped bore 64 which opens into an enlarged
diameter bore 66. Bore 66 extends from the hex shaped bore 64 to
the lower end of sleeve 60. With the piston head 24 in a retracted
position, a segment of the length of shaft 26 within sleeve 60 is
complementarily hex shaped to the hex shaped bore 64, the hex
shaped shaft segment being designated 68 and extending downwardly
from the upper end of sleeve 60 to a location just above cutter
blades 70. It will be appreciated that with the foregoing described
construction, shaft 26 is thus splined to cutter sleeve 60 and
sleeve 60 is therefore rotatable with shaft 26.
Intermediate the ends of sleeve 60 there are provided a plurality
of elongated circumferentially spaced slots 72 opening through the
wall of sleeve 60. A cutting blade 70 is disposed in each of the
slots 72 and particularly each cutting blade 70 comprises an
elongated bracket pivoted about a pin 74 secured to sleeve 60 at
one end of the corresponding slot 72. Each bracket is generally
L-shaped and has one leg which projects inwardly to define a cam
surface or follower 76 along its inner edge. A cutting edge 78 is
provided at the lower end of each bracket. Each bracket is thus
pivotal between a position retracted within sleeve 60 as
illustrated in FIG. 11 wherein the bracket and cutting edge are
located within the cylindrical confines of the cutter and an
extended position wherein the cutting edges 78 engage the wall of
pipe casing P and cut the same in response to rotation of shaft 26
as set forth below. In order to displace the cutting blades 70 into
a radially extended position and into cutting engagement with the
wall of pipe casing P, the lower end of shaft 26 below the hex
shaped segment 68 is provided with risers 80 which taper radially
outwardly toward the lower end of shaft 26. The outer surfaces 82
of risers 80 engage cam followers 76 on the cutting brackets 70 to
cam the latter outwardly in response to axial upward movement of
shaft 26 relative to cutting sleeve 60. Suitable springs, now
shown, may be utilized to bias the cutter blades for movement
toward their retracted positions.
In operation, pipe cutter 10 is lowered by cable 22 into the well
bore and located at a depth such that the cutting edges 78 are
disposed at the location of the desired cut. Once located, the pipe
cutter is actuated to automatically and substantially
simultaneously to extend jaws 40 to grip the pipe casing walls and
thereby hold the pipe cutter in position at the desired depth and
against rotation, to extend the cutting blades into engagement with
the pipe casing and rotate the cutter section such that the cutting
edges cut the pipe. Preferably, an expanding gas charge is
introduced into cylinder 12 below piston head 24 causing initial
relative axial displacement of shaft 26 and the annular outer
elements of the pipe cutter. For example, a power charge 90 and cap
92 can be disposed below the piston 24 with a wire 94 connected to
a terminal 96 on the cylindrical wall section 12. An insulated
electrical wire 98 may be run along the outside of wall 12 and
electrically connected at its lower end to terminal 96. The cap 92
is then fired upon closing an electrical switch, not shown, above
ground, thereby actuating the power charge 90.
Relative initial axial displacement of the shaft and pipe cutter
sections causes cam surface 58 on shaft 26 and the cam followers 50
of jaws 40 to cooperate such that jaws 40 are first pivoted
outwardly about axis 42 into engagement with the pipe wall. Once
engaged, the enlarged diameter portion 56 on shaft 26 engages cam
followers 50 to displace the lower ends of the jaws outwardly such
that the surfaces 44 lie flush against the pipe casing walls
throughout their lengths whereby the grip section and the sections
of the pipe cutter rigidly attached thereto including the gear and
cylinder sections are rigidly attached to the pipe wall against
axial and rotational displacement.
Initial relative axial displacement of the shaft 26 and the gear,
grip and cutter sections causes the risers 80 to cam against the
cam followers 76 on the cutting brackets causing laterally outward
displacement of the cutting edges toward and into engagement with
the interior wall of pipe casing P. Once the gear section is fixed
against rotation by the engagement of the jaws 40 against the pipe
casing wall, shaft 26 rotates relative to the gear and grip
sections upon continued axial displacement of the piston and
cylinder by virtue of its geared connection with gear section 14.
Rotation of shaft 26 also causes rotation of cutting sleeve 60
through its splined connection with shaft 26 whereby the shaft 26
including risers 80 as well as the cutting edges 78 rotate in
unison. Consequently, as shaft 26 is displaced axially upwardly due
to the screw or gear type action between it and the gear sleeve 32,
the cutting edges not only rotate to cut the pipe internally but
are also continuously urged further radially outwardly such that
the blades cut through the pipe.
When shaft 26 is displaced axially upwardly a distance equal to the
length of enlarged diameter portion 56, the reduced diameter
portion of shaft 26 below shaft portion 56 lies in lateral registry
with the cams 50 of jaws 40. This releases the engagement of jaws
40 against the pipe wall enabling the jaws to return to their
retracted positions within the cylindrical confines of the pipe
cutter. Since risers 80 at the lower end of shaft 26 substantially
correspond in length to the length of the enlarged diameter section
54 of the shaft 26 the lower end of shaft 26 clears the inner cam
followers 76 of the cutting brackets 70 at substantially the same
time that the jaws 40 are released from engagement with the pipe
casing P. Thus, jaws 40 as well as the cutting brackets 70 are
substantially simultanesously permitted to retract within the
confines of the pipe cutter. Thus, the pipe cutter can be hauled
out of the well bore or lowered therein simply by hauling in or
paying out cable 22.
The power charge used to extend the piston in cylinder 12 may be of
the type manufactured by Baker Oil Tools, Inc., Model K-2, Wire
Line Setting Tools Unit No. 1891. Alternatively, a vacuum can be
introduced into cylinder 12 above the piston head by suitable known
equipment with like results as previously described. Also, a
frangible plug may be located in the wall of cylinder 12 below the
piston head and which plug will shatter when sufficient external
pressure is applied. Thus, well fluid can be forced through the
opening into the cylinder below the piston head with sufficient
pressure to cause axial displacement of shaft 26 and to achieve the
foregoing described results. It will also be appreciated that the
relative orientation of the cutter in the well bore can be reversed
with the shaft 26 movable downwardly once the cutter is fixed to
the pipe casing and that such reversal causes like operation of the
pipe cutter and achieves similar results as previously
described.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiments are therefore to be considered in all respects
as illustrative and not restrictive, the scope of the invention
being indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalancy of the claims are therefore intended to be
embraced therein.
* * * * *