Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS AND METHOD FOR SLOTTING A PIPE
FIELD OF INVENTION
The present invention relates to an apparatus and a method for slotting a pipe
to form at least one slot therein, wherein the apparatus and the method
provide improved
clamping of the pipe during slotting such that the dimensions and
configuration of the slots
formed in the pipe may be more closely controlled. Preferably, the pipe is for
use in the
production of oil from formations that contain heavy oil or tar sands.
BACKGROUND OF INVENTION
In tar sands and heavy oil recovery, a pipe, being a casing, tubing or other
liner, is typically installed in a wellbore for production of oil from an
underground
formation or producing zone. The pipe is preferably perforated or slotted
about its
circumference before placement in the wellbore. The desired length and width
of the slots
perforated in the pipe and the desired number of slots depend upon various
factors,
including the granular size of any sand in the formation, the minimum strength
and integrity
of the pipe required for the particular application or use of the pipe and the
rate of the
oil/sand influx into the pipe.
Further, the slots may be straight or keystone. A straight slot has the same
slot width on the inside and outside diameter of the pipe. A straight slot is
used when sand
control is not a major concern or the sand granular size is relatively large.
The keystone
slot has a larger width slot on the inside diameter, than on the outside
diameter, of the pipe.
The keystone slot is used when plugging of the slot from sand is a concern.
The outside
diameter of the slot controls the sand granular size permitted to enter the
pipe, while the
larger inside diameter permits the sand to pass from the slot into the pipe.
Various apparatuses and methods have been developed for slotting pipe for
use in the production of oil. For instance, United States of America Patent
No. 1,760,075
issued May 27, 1930 to McCullough et al is directed at a machine for cutting
or forming an
"improved perforation" in a pipe having "inwardly divergent side walls and
inwardly
convergent end walls", often referred to as a keystone slot. The machine is
comprised of a
frame, a pipe carriage carried by the frame, a pipe rack mounted on a carriage
head and
which is also carried by the frame, a plurality of blades carried by the head,
and operating
means for the blades. Keystone slots are cut in a single row in the casing by
rotating the
pipe rack about the top dead centre axis of the pipe.
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In McCullough et al, the pipe to be perforated is secured in the machine by
placing it in a pipe rack, which includes an elongate body and a plurality of
V-shaped pipe
holders, and engaging a pivoting ann against the surface of the pipe. A
plurality of cutter
units carried by a carnage head are then moved downwaxdly so that the cutter
units engage
the uppermost portion of the pipe referred to as the longitudinal pivotal axis
of the pipe.
The cutter blades of the cutter units are fed into the pipe for the desired
distance and then
withdrawn from the pipe. Thus, the depth or distance of penetration of the
cutter blade into
the pipe is determinative of the length of the perforation or slot formed
therein.
Subsequently, the pipe is rotated about the longitudinal pivotal axis of the
pipe, followed by
repeating the movement of the carriage head downwaxdly in the manner described
above.
Thus, the cutting action is performed by a single cutting motion, being the
movement of the
cutter units downward vertically into the pipe for a desired distance.
United States of America Patent No. 2,629,920 issued March 3, 1953 to
Pridy is also directed at a machine for perforating pipe. The pipe is
supported on a cradle
comprised of opposed inclined members during the slotting operation. More
particularly, a
roller is positioned in the trough formed by the opposed inclined members of
the cradle for
supporting the pipe thereon.
Further, the machine of Pridy provides for a cutter head, comprised of a
series of metal saws, to be held rigidly while causing the pipe to be
perforated to move
toward and away from the cutter head as the slotting operation takes place.
Specifically, the
pipe is movable vertically towards and away from the cutter head for
perforation by the
metal saws to slit the pipe, while being restrained from horizontal movement.
Thus, the
depth or distance of penetration of the metal saws into the pipe is solely
determinative of
the length of the perforation or slot formed therein. The cutting action is
performed by a
single cutting motion, being the movement of the pipe upward vertically toward
the cutting
head for a desired distance.
German Patent Application No. DE 32 13 464 Al published April 10, 1983
by Schaubstahl-Werke relates to a slotting device which includes a sliding
carnage having
two bearing pedestals that contain one rotatable chuck each. The casing is
held in position
between the frontal surfaces of the chucks of the bearing pedestals on the
sliding carriage
such that the chucks permit the casing to be rotated about its longitudinal
axis.
The slotting tools, which are preferably buzz saws, are moved vertically into
contact with the casing to cut the slot therein. The length of each individual
longitudinally
slotted hole depends upon the depth of penetration of the buzz saw into the
casing. Once
the pre-set depth of penetration of the buzz saw is reached, the saw is
retracted from the
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casing. The sliding carnage is then moved horizontally in order to move the
casing into a
different position for the next cutting motion. Thus, the length of the slots
to be cut in the
casing is determined by the diameter of the cutting blade of the buzz saws.
United States of America Patent No. 3,209,632 issued October 5, 1965 to
Reining is directed at two embodiments of a slotting device. In a first
embodiment, the
casing or pipe moves over and in contact with a carriage-cam wheel which is
rotatably
mounted on a horizontal shaft. More particularly, the pipe is disposed in a
groove defined
by the carnage-cam wheel. A single cutter is rockably mounted above the
carriage-cam
wheel and is supported at its forwardmost end by a cam follower which has a
roller
disposed on its lower end. The roller of the cam follower is in contact with
and may roll
along a ramming surface of the carnage-cam wheel.
In a second embodiment of Reining, the pipe or casing lies within a trough
formed for that purpose in a longitudinal carnage having an upper caroming
surface and
which operates similarly to that of the carriage-cam wheel of the first
embodiment. The
longitudinal carriage is slidable in a horizontal direction.
In operation, the pipe or casing moves over the carriage-cam wheel of the
first embodiment, or within the longitudinal carriage of the second
embodiment, causing the
caroming surface to movably engage the cam roller. The engagement of the
roller with the
ramming surface raises and lowers the single cutter out of and into contact
with the casing.
In particular, the cam roller rides upon a first raroped portion of the
ramming surface which
gradually lowers the cutter into contact with the casing. The cam roller then
rides into a
depressed portion of the ramming surface, during which time the cutter
continues to cut the
casing. When the cam roller rides upon a second ramped portion of the ramming
surface,
the cutter is raised out of contact with the casing and the cutting motion for
that slot is
completed.
Conventional apparatuses for slotting pipe, such as those described above,
typically include a cutting head which is comprised of a number of blades or
circular saws.
These blades are moved through the casing to create the slot in a manner such
that the
length of the slot is determined by the diameter of the cutting blade. As the
diameter of the
blade is increased, in order to lengthen the slot, blade stability may
decrease, which may
result in greater blade breakage, less control over any slot width deviation,
decreased
cutting speeds and an inability to cut slots having relatively smaller slot
widths.
Accordingly, the length of the slot that can be cut in the casing by a
conventional slotting
apparatus may be limited. As well, the precision with which the slot may be
cut may also
be limited resulting in decreased control over the slot configuration and
dimensions.
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Further, conventional apparatuses for slotting pipe, such as those described
above, provide limited clamping or securing of the pipe by the apparatus
during the slotting
operation. As a result, the precision with which the slot may be cut may again
be adversely
affected. To cut a more precise slot, it is desirable that the pipe be
securely maintained in a
desired position during the slotting operation. However, as discussed above,
many
apparatuses do not provide any means or mechanism, or provide an insufficient
or
unsatisfactory means or mechanism, for securing the pipe with the apparatus.
As result,
unwanted vibration or movement of the pipe occurs during the slotting
operation.
There is therefore a need in the industry for an apparatus and a method for
slotting a pipe which permit relatively greater control and precision with
respect to the
dimensions of each slot and the configuration or pattern of the slots cut in
the pipe, as
compared to conventional slotting apparatuses and methods. Further, there is a
need for a
method and an apparatus which provide improved clamping or securing of the
pipe during
slotting of the pipe in order to improve the precision with which the slots
may be cut. In
addition, when utilizing blades to perforate the pipe, there is a need for a
method and an
apparatus wherein the length of the slots cut by the apparatus and the method
are preferably
not limited or solely determined by the diameter of the blades.
SUMMARY OF INVENTION
The present invention relates to an apparatus and a method for slotting a
casing or pipe which permit relatively greater control over, and relatively
greater flexibility
and variation with respect to, the length and width of the slots cut in the
casing, as
compared to conventional slotters. Further, the invention relates to an
apparatus and a
method for slotting a pipe which may permit the length of the slot to be
varied, while
maintaining a desired width of the slot. More particularly, the apparatus and
the method
may permit relatively longer slot lengths, and relatively narrower slot
widths, to be cut in
conventional casing as compared to slots cut by conventional slotters. When
blades are
used in the apparatus and method to cut the pipe, the length of the slots are
preferably not
limited or solely determined by the diameter of the blades used. Finally, the
invention
relates to an apparatus which may permit the full length or entire joint of
the pipe to be
slotted by a row of slots in a single process or operation.
In an apparatus aspect, the invention is an apparatus for slotting a pipe, the
pipe having a pipe length, a pipe wall and a pipe longitudinal axis, the pipe
wall having a
pipe external surface defining a pipe circumference, the apparatus comprising:
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(a) a stationary pipe bed for supporting the pipe, the pipe bed having a pipe
bed
length;
(b) a clamping system associated with the pipe bed and having a clamp length,
the clamping system being movable between a clamped position for
releasably securing the pipe to the pipe bed and an unclamped position,
wherein the clamping system is comprised of a clamping surface adapted to
engage in the clamped position at least about 50 percent of the pipe
circumference and at least about 50 percent of the pipe length, and wherein
the clamping system in the clamped position defines a longitudinal clamping
gap extending along the clamp length which is oriented to permit the slotting
of the pipe therethrough;
(c) a movable cutting head located adjacent to the pipe bed, the cutting head
comprising a plurality of cutters for slotting the pipe, the cutters linearly
arranged along the cutting head in a row substantially parallel to the
longitudinal clamping gap;
(d) a first perforating mechanism for moving the cutting head toward and away
from the longitudinal clamping gap such that the pipe wall is perforated by
the cutters through the longitudinal clamping gap at a location of contact
between the cutters and the pipe wall;
(e) a second longitudinal cutting mechanism, operable independently from the
first perforating mechanism, for moving the cutting head longitudinally
relative to the pipe bed along the longitudinal clamping gap such that the
perforated pipe wall is further cut by the cutters through the longitudinal
clamping gap to form a plurality of discrete slots, each of the slots having a
slot length; and
(f) a third indexing mechanism for rotating the pipe about the pipe
longitudinal
axis when .the clamping system is in the unclamped position, in order to vary
the location of contact between the cutters and the pipe wall about the pipe
circumference.
In a method aspect, the invention is a method for slotting a pipe, the pipe
having a pipe length, a pipe wall and a pipe longitudinal axis, the pipe wall
having a pipe
external surface defining a pipe circumference, the method comprising the
steps of
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(a) positioning the pipe on a stationary pipe bed;
(b) moving a clamping system associated with the pipe bed to a clamped
position to releasably secure the pipe to the pipe bed, the clamping system
comprising a clamp length and a clamping surface, such that the clamping
surface engages at least about 50 percent of the pipe circumference and at
least about 50 percent of the pipe length, and such that the clamping system
defines a longitudinal clamping gap extending along the clamp length which
is oriented to permit the slotting of the pipe therethrough;
(c) providing a movable cutting head at a location adjacent to the pipe bed,
the
cutting head comprising a plurality of cutters for slotting the pipe, the
cutters
linearly arranged along the cutting head in a row substantially parallel to
the
longitudinal clamping gap;
(d) first moving the cutting head in a direction toward the longitudinal
clamping
gap to move the cutters into engagement with the pipe wall such that the
pipe wall is perforated by the cutters through the longitudinal clamping gap
at a location of contact between the cutters and the pipe wall;
(e) second moving the cutting head longitudinally relative to the pipe bed
along
the longitudinal clamping gap, wherein the second moving step is performed
independently from the first moving step and in sequence following the first
moving step, such that the perforated pipe wall is further cut by the cutters
through the longitudinal clamping gap to form a first plurality of discrete
slots, each of the slots having a length;
(f) third moving the cutting head away from the longitudinal clamping gap so
that the cutters are moved out of engagement with the pipe wall;
(g) moving the clamping system to an unclamped position from the clamped
position;
(h) rotating the pipe about the pipe longitudinal axis; and
(i) repeating steps (a) through (f) to form a second plurality of discrete
slots,
wherein the first plurality of discrete slots and the second plurality of
discrete slots are spaced circumferentially about the pipe circumference.
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As indicated, the pipe bed has a pipe bed length. The pipe bed length may
be any length which is capable of supporting the pipe without undue movement
or sagging
of the pipe. The pipe bed may provide for either continuous or intermittent
support of the
pipe along the pipe bed length. Preferably, however, the pipe bed length is
about as long as
the pipe length or greater and provides for substantially continuous support
of the pipe
along the pipe bed length so that the pipe is supported by the pipe bed
substantially
continuously along substantially its entire length.
As indicated, the clamping system has a clamp length. The clamp length is
the overall length of the clamping system. The clamp length may be shorter,
longer or the
same length as the pipe bed length. Preferably, however, the clamp length is
such that it
extends along substantially the entire pipe length when the pipe is supported
on the pipe
bed.
An important feature of the invention is the extent to which the clamping
surface engages the pipe external surface when the clamping system is in the
clamped
position. The clamping surface must engage at least about 50 percent of the
pipe
circumference in the clamped position in order to distribute the clamping
force exerted by
the clamping system and in order to provide a relatively positive engagement
between the
clamping surface and the pipe wall.
Preferably, however, the clamping surface engages more than 50 percent of
the pipe circumference in the clamped position. In the preferred embodiment
the clamping
surface engages between about 70 percent and about 90 percent of the pipe
circumference
in the clamped position, depending upon the size of the pipe which is being
clamped. The
clamping surface may, however, engage more than 90 percent of the pipe
circumference.
The only upper limit of the extent to which the clamping surface may engage
the pipe
circumference is that the clamping system must provide a suitable width of
longitudinal
clamping gap along the clamp length for facilitating cutting of the slots in
the pipe.
The clamping surface must engage at least about 50 percent of the pipe
length in order to distribute the clamping force exerted by the clamping
system and in order
to provide a relatively positive engagement between the clamping surface and
the pipe wall.
Preferably the clamping surface is configured so that it extends either
continuously or
intermittently along substantially the entire clamp length. As a result, there
may be
transverse gaps or spaces in the clamping surface along the clamp length as
long as the
clamping surface engages at least about 50 percent of the pipe length.
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Preferably, however, the clamping surface engages more than 50 percent of
the pipe length in the clamped position. In the preferred embodiment the
clamping surface
engages at least about 70 percent of the pipe length in the clamped position.
The clamping
surface may, however, engage as much as 90 percent or even 100 percent of the
pipe length
in the clamped position.
In the preferred embodiment the clamping system is comprised of a plurality
of clamps which collectively comprise the clamping surface. The plurality of
clamps are
longitudinally spaced along the clamp length for engaging the pipe
circumference in the
clamped position. The plurality of clamps may be configured to provide for
continuous or
intermittent clamping along the pipe length. Preferably the clamps are
separated
longitudinally so that there are transverse gaps between the clamps, thus
reducing the
likelihood of interference between adjacent clamps. Preferably, however, the
size of these
gaps is minimized in order to maximize the amount of the pipe length which is
engaged by
the clamping surface. In the preferred embodiment the size of the gaps between
adjacent
clamps is in the order of several inches, preferably about two inches (5.0g
cm).
The clamping system may comprise any structure or apparatus which is
capable of moving between the clamped position and the unclamped position and
which is
capable of providing the minimum required engagement of the clamping surface
about the
pipe circumference and along the pipe length.
In the preferred embodiment, each clamp is comprised of a pair of clamp
arms, which clamp arms define the longitudinal clamping gap between them when
they are
in the clamped position. At least one of the clamp arms is movable relative to
the other
clamp arm so that the clamp can be moved between the clamped position and the
unclamped position.
The clamping system may be powered by any type of power system,
including electric, mechanical, pneumatic and hydraulic systems. In the
preferred
embodiment the clamping system is powered by a hydraulic system and the
clamping
system is further comprised of at least one hydraulic cylinder which may be
actuated to
move the clamping system between the clamped position and the unclamped
position.
The first perforating mechanism may be comprised of any structure or
apparatus which is operable to move the cutting head relative to the pipe bed
in order to
bring the cutters into and out of engagement with the pipe wall. Preferably
the first
perforating mechanism is comprised of a mechaiusm which is capable of
providing
relatively precise control over the movement of the cutting head in order to
avoid or
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minimize cutter blade breakage. The use of a worm or screw jack type-apparatus
as a
component of the first perforating mechanism has been found to be advantageous
in this
regard.
In the preferred embodiment, the first perforating mechanism is comprised
of:
(a) a movable frame for supporting the cutting head adjacent to the pipe bed
such that the row of cutters is movable towards and away from the
longitudinal clamping gap in order to move the cutters into and out of
contact with the pipe wall;
(b) a carriage for supporting the movable frame, wherein the carnage is
movable
longitudinally relative to the pipe bed and wherein the carriage is associated
with the movable frame such that longitudinal movement of the carriage
relative to the pipe bed is translated into movement of the cutters either
towards or away from the longitudinal clamping gap; and
(c) a gear assembly comprised of a rack and worm, wherein the rack is
operatively connected with the carnage such that rotation of the worm
moves the carnage longitudinally relative to the pipe bed.
The second longitudinal cutting mechausm may be comprised of any
structure or apparatus which is operable to move the cutting head
longitudinally relative to
the pipe bed in order to form the plurality of discrete slots which each have
a slot length.
Preferably the second longitudinal cutting mechanism is comprised of a
mechanism which
is capable of providing relatively precise control over the longitudinal
movement of the
cutting head in order that the slot length can be controlled and in order that
cutter blade
breakage can be avoided or minimized. The use of a worm or screw jack type-
apparatus as
a component of the second longitudinal cutting mechanism has been found to be
advantageous in this regard.
In the preferred embodiment the second longitudinal cutting mechanism is
comprised of a rack and worm gear assembly, wherein the rack is operatively
connected
with the cutting head such that rotation of the worm moves the cutting head
relative to the
pipe bed along the longitudinal clamping gap.
The third indexing mechanism may be comprised of any structure or
apparatus which is operable to rotate the pipe about the pipe longitudinal
axis in order to
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vary the location of contact between the cutters and the pipe wall about the
pipe
circumference. Preferably the third indexing mechanism is comprised of a
mechanism
which is capable of providing relatively precise control over the rotation of
the pipe so that
careful control over the positions of the locations of contact between the
cutters and the
pipe wall can be maintained, thus enabling the apparatus to cut precise slot
configurations
in the pipe wall. The use of a worm or screw jack type-apparatus as a
component of the
third indexing mechanism has been found to be advantageous in this regard.
In the preferred embodiment, the third indexing mechanism is comprised of:
(a) a rotatable head for releasably securing the pipe such that rotation of
the
rotatable head rotates the pipe about the pipe longitudinal axis, wherein the
rotatable head is comprised of a gear wheel; and
(b) a worm operatively associated with the gear wheel such that rotation of
the
worm actuates the gear wheel to rotate the rotatable head.
The apparatus and method of the present invention therefore provide a
precision system which is capable of maintaining precise control over a pipe
slotting
procedure, thus enabling the cutting of slot configurations which have
previously been
difficult to attain while minimizing losses and downtime associated with
cutter blade
breakage.
SUMMARY OF DRAWINGS
Embodiments of the invention will now be described with reference to the
accompanying drawings, in which:
Figure 1 is an end view of a preferred embodiment of the apparatus, showing
a cutting head and pipe bed of the apparatus;
Figure 2 is a side view of the apparatus taken along lines 2 - 2 of Figure 1,
wherein the pipe bed has been removed;
Figure 3 is a pictorial back view of a clamp comprising a clamping system of
the pipe bed, wherein the clamp has a break-away portion showing a portion of
the pipe
therein;
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Figure 4 is a pictorial front view of the clamp shown in Figure 3, showing a
clamp linkage mechanism;
Figure 5 is an end view of the clamp shown in Figure 3, wherein the
clamping system is in a clamped position;
Figure 6 is an end view of the clamp shown in Figure 3, wherein the
clamping system is in an unclamped position;
Figure 7 is a pictorial front side view of a cutting box of the cutting head
of
the apparatus as shown in Figures 1 and 2;
Figure 8 is a pictorial back side view of the cutting box shown in Figure 7;
Figure 9 is an exploded longitudinal section of a front end of a spindle of
the
cutting box shovcni in Figure 7;
Figure 10 is a schematic diagram of a pulley system of the cutting box
shown in Figure 7;
Figure 11 is an end view of an indexing mechanism of the apparatus
including a hollow spindle chuck; and
Figure 12 is a pictorial view of the indexing mechanism shown in Figure 11
having the hollow spindle chuck removed therefrom.
DETAILED DESCRIPTION
Referring to Figures 1 and 2, the invention is directed at an apparatus (20),
and an associated method, for slotting a length of a pipe (22) or conduit at a
desired
location. Preferably, the invention is used for slotting pipe to be used for
the production of
oil through a wellbore from an underground formation or producing zone. Thus,
the pipe
(22) will preferably be comprised of a casing, tubing or other liner to be
installed in the
wellbore such that the oil is produced, or brought to the surface, through the
casing, tubing
or liner. However, this invention may be used for slotting pipe required for
any use or
application. Further, the invention may be used for slotting any type of pipe
compatible
with the apparatus (20) or method, in that the pipe has sufficient structural
strength or
integrity to withstand the slotting method or the operation or process
performed by the
apparatus (20).
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The pipe (22) has a pipe wall (24) defining a bore (26) of the pipe (22), a
pipe length and a longitudinal axis extending therethrough. Further, the pipe
wall (24) has
an external surface (28) defining a pipe circumference. One or more slots
(30), and
preferably a plurality of slots (30), are formed in the pipe wall (24).
In the preferred embodiment, as described below, the slots (30) are formed in
a row extending along the pipe (22) and preferably aligned substantially
parallel to the
longitudinal axis of the pipe (22). Further, preferably a plurality of rows of
slots (30) are
formed in the pipe wall (24) about the pipe circumference. The method and the
apparatus
preferably provide for or permit the versatile, yet accurate, arrangement of
the rows of slots
(30) in varying configurations or patterns about the pipe circumference. For
instance, the
rows of slots (30) may be arranged such that adjacent slots (30) are side by
side, in a
staggered or offset arrangement or in a spiral or helical arrangement about
the pipe
circumference. In order to cut the rows of slots in a precise pattern or
configuration, the
slotting of the pipe (22) must be performed in a precise and controlled manner
to ensure the
proper and accurate placement of the slots (30) in the pipe wall (24).
As indicated, in order to provide for the various desired slotting
configurations or patterns, the apparatus (20) and method of the within
invention permit the
cutting of the slots (30) at relatively precise circumferential and
longitudinal positions in
the pipe wall (24), as compared to conventional methods and apparatuses.
The number of slots (30) cut along the pipe length may be varied as required
for any particular application. Generally, the number of slots (30) required,
or desired, will
be dependent upon, amongst other factors, the amount of pipe (22) that will be
removed
from the slots (30) in relationship to the total cross-sectional area of the
pipe (22).
Conventionally, the circumferential area of the pipe (22) removed by the slots
(30) is about
3%. The percentage of cross-sectional area which may be removed will be
dependent upon,
amongst other factors, the desired strength of the pipe (22) and the desired
open flow area
provided by the slots (30).
Preferably, the apparatus (20) accommodates, and is operable on, varying
lengths of pipe (22), varying diameters of pipe (22) and varying thicknesses
of the pipe wall
(24). With respect to the pipe length, the preferred embodiment of the
apparatus (20)
accommodates the total length of the pipe (22) such that a row of slots (30)
may be formed
concurrently or simultaneously along substantially the full or total pipe
length or entire joint
of the pipe (22). Typically an average joint length of casing is approximately
40 feet
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(12.192 m) long. Thus, in the preferred embodiment, the apparatus (20) is
capable of
handling pipe lengths of less than or equal to at least about 40 feet (12.192
m).
With respect to the pipe diameter, the apparatus (20) may be adapted to
accommodate varying diameters of pipe (22) as discussed further below.
However, the
preferred embodiment of the apparatus (20) may be adapted to permit the
accommodation
of pipe diameters between about 4 inches (10.16 cm) and 9 5/8 inches (24.45
cm). Finally,
conventional casing typically has a wall tluckness of about 0.5 inches (1.27
cm). Therefore,
in the preferred embodiment, the apparatus (20) accommodates pipes (22) having
a wall
thickness of less than or equal to at least about 0.5 inches (1.27 cm).
However, again, the
apparatus (20) may be adapted to accommodate varying pipe wall (24)
thicknesses.
Referring to Figures 1 and 2, the apparatus (20) has a front end (32) and a
back end (34). The pipe (22) is preferably loaded and unloaded from the
apparatus (20) at
the front end (32). Further, the apparatus (20) is comprised of a stationary
frame (36) for
supporting and mounting the other elements of the apparatus (20) thereon. The
stationary
frame (36) provides structural support for the apparatus (20) and may be
comprised of any
suitable material for providing such a structural framework for the apparatus
(20), such as
lengths of steel tubing welded or bolted together into the desired
configuration or structure
to form the frame (36).
Referring to Figures l and 2, the apparatus (20) is further comprised of a
stationary pipe bed (38), a clamping system (40) associated with the pipe bed
(38) and a
movable cutting head (42). The stationary pipe bed (38) is mounted with the
stationary
frame (36) in a fixed position or location on the stationary frame (36). The
clamping
system (42) is associated with the pipe bed (38) for releasably securing the
pipe (22) to the
pipe bed (38). The movable cutting head (40) is supported adjacent the pipe
bed (38) by a
movable frame (44), wherein the movable frame (44) is movably mounted with or
movably
supported on the stationary frame (36).
The pipe bed (38) is provided for supporting the pipe (22) thereon. Further,
the pipe bed (38) has an upper surface (46) and a lower surface (48). Any
surface or portion
of the pipe bed (38) may be mounted with the stationary frame (36), However,
preferably at
least the lower surface (48) of the pipe bed (38) is mounted with the
stationary frame (36) to
maintain the position or location of the pipe bed (38) during slotting of the
pipe (22) by the
apparatus (20). Further, the clamping system (40) may be associated with the
pipe bed (38)
in any manner permitting the clamping system (40) to releasably secure the
pipe (22) to the
pipe bed (38) in a desired position. In the preferred embodiment, the clamping
system (40)
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is associated with the upper surface (46) of the pipe bed (38) for ease of
access to the pipe
(22) by the cutting head (42).
As well, the pipe bed (38) has a pipe bed length. The pipe bed (38) may
have any pipe bed length capable of supporting the pipe (22) thereon. However,
preferably
the pipe bed length is selected to be compatible with the pipe length such
that the pipe (22)
is supported by the pipe bed (38) substantially along the entire pipe length.
Referring to Figure 3 - 6, the clamping system (40) has a clamp length. The
clamping system (40) may have any clamp length capable of releasably
supporting the pipe
(22) on the pipe bed (38). However, preferably the clamp length is selected to
be
compatible with the pipe bed length and thus the pipe length. Preferably, the
clamp length
extends along substantially the entire pipe bed length Accordingly, the pipe
(22) is
preferably releasably secured by the clamping system (40) substantially along
the entire
pipe length.
The clamping system (40) is movable between a clamped position for
releasably securing the pipe (22) to the pipe bed (38), as shown in Figure 5,
and an
unclamped position, as shown in Figure 6. In the unclamped position, the
clamping system
(40) preferably opens sufficiently for easy access to the pipe (22) therein so
that it may be
readily removed from the clamping system (40).
Further, the clamping system (40) is comprised of a clamping surface (50)
adapted to engage the pipe wall (24) in the clamped position. The surface area
of the pipe
wall (24) engaged by the clamping surface (50) may vary so long as the
engagement
between the pipe wall (24) and the clamping surface (50) is sufficient to
firmly secure the
pipe (22) in the desired position during slotting.
It has been found that in previous slotting apparatuses, in order to secure
the
pipe (22) in a desired position, that a relatively high clamping force on the
pipe wall (24)
may be required. Depending upon the size of the slots (30) and thickness of
the pipe wall
(24), the clamping force required to inhibit movement or vibration of the pipe
(22) was
found to be sufficient to crush the pipe (22) in some circumstances. As a
result, the
clamping surface (50) of the clamping system (40) of the within invention is
adapted to
engage the pipe wall (24) in a manner inhibiting any unwanted movement of the
pipe (22)
during slotting while applying a reduced clamping force to the pipe wall (24).
Specifically,
the clamping system (40) increases the surface area of the pipe wall (24)
engaged by the
clamping surface (50), which in turn, may reduce the clamping force required
to retain the
position of the pipe (22).
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More particularly, the clamping surface (50) is adapted to engage in the
clamped position at least about 50 percent of the pipe circumference and at
least about 50
percent of the pipe length. Further, in order to permit the slotting of the
pipe (22) in the
clamped position, the clamping system (40) in the clamped position defines a
longitudinal
clamping gap (52) extending along the clamp length which is oriented to permit
the slotting
of the pipe (22) therethrough. The specific percent of the pipe circumference
and the pipe
length to be engaged by the clamping surface (50) may each be increased above
50 percent
as required to securely engage the pipe (22) while applying a clamping force
that will not
significantly damage or adversely impact the structural integrity of the pipe
(22). The
particular percentages will thus vary depending upon, amongst other factors,
the size and
positioning of the slots (30) in the pipe (22) and the thickness of the pipe
wall (24).
Further, as indicated, each of the percentages must be selected while still
providing for the
longitudinal clamping gap (52).
For instance, preferably, the clamping surface (50) is adapted to engage at
least about 70 percent of the pipe circumference in the clamped position, and
more
preferably at least about 90 percent of the pipe circumference in the clamped
position.
Further, preferably, the clamping surface (50) is adapted to engage at least
about 70 percent
of the pipe length in the clamped position, and more preferably at least about
90 percent of
the pipe length in the clamped position. Any combination of percentages of
engagement of
the pipe length and the pipe circumference may be used. However, in the
preferred
embodiment, a combination of percentages is used wherein the clamping surface
(50) is
adapted to engage at least about 95 percent of the pipe circumference and at
least about 90
percent of the pipe length in the clamped position.
The clamping surface (50) may be comprised of any structural component or
member of the clamping system (40). However, preferably, the clamping system
(40) is
comprised of at least one clamp (54) which comprises the clamping surface
(50). However,
in order to support and secure the entire pipe length, in the preferred
embodiment, the
clamping system (40) is comprised of a plurality of clamps (54) which
collectively
comprise the clamping surface (50). The clamps (54) are longitudinally spaced
along the
pipe bed length for engaging the pipe circumference in the clamped position.
The particular
number of clamps (54) required will vary depending upon the pipe length. In
the preferred
embodiment, 20 clamps (54) are longitudinally positioned along the pipe bed
(38) a spaced
distance apart. More particularly, the clamps (54) are spaced longitudinally
about 2 inches
(5.08 cm) apart.
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Each clamp (54) may be comprised of any suitable clamping device,
structure, member or mechanism capable of providing the desired clamping
surface (50) for
engaging the pipe wall (24). Referring to Figured 3 - 6, in the preferred
embodiment, each
clamp (54) is comprised of a pair of clamp arms (56). In the unclamped
position of the
clamping system (40) as shown in Figure 6, the clamp arms (56) are capable of
being
moved apart to permit ready access to the pipe (22). In the clamped position
of the
clamping assembly (40) as shown in Figure 5, the clamp arms (56) define the
longitudinal
clamping gap (52) therebetween. The innermost or internal surface of the clamp
arms (56)
comprise the clamping surface (50) and are thus shaped or configured to be
compatible with
the pipe wall (24) to be clamped therein to provide the desired engagement
between the
pipe wall (24) and the clamping surface (50).
At least one of the clamp arms (56) is movable relative to the other clamp
arm (56) to permit the movement of the clamping system (40) between the
clamped and
unclamped positions. Although both clamp arms (56) may be movable, in the
preferred
embodiment, the pair of clamp arms (56) includes a stationary clamp ann (58)
and a
movable clamp arm (60). Each of the stationary and movable clamp arms (58, 60)
has
opposed side ends (62) defining a length of the clamp arm therebetween, an
upper end (64)
and a lower end (66). Further, each of the stationary and movable clamp arms
(58, 60) has
an inner surface (68) which comprises the clamping surface (50) and an opposed
outer
surface (70).
In the clamped position, the longitudinal clamping gap (52) is defined
between the adjacent upper ends (64) of the stationary and movable clamp arms
(58, 60).
The distance between the upper ends (64) defines the width of the longitudinal
clamping
gap (52), which will vary depending upon the percentage of the pipe
circumference engaged
by the clamping surface (50). However, at a minimum, the width of the
longitudinal
clamping gap (52) in the clamped position must be sufficient to permit the
slotting of the
pipe (22) therethrough.
Further, as indicated, the inner surface (68) of each clamp (58, 60) is sized
to
accommodate the pipe circumference. Accordingly, to accommodate varying sizes
of pipe
(22), and particularly pipe circumferences, the clamp arms (58, 60) are
preferably
removable and replaceable such that the clamp arms (58, 60) may be
interchanged as
necessary to be compatible with the pipe (22) to be clamped therebetween. As
described in
detail below, the clamping system (40) therefore provides a structure
permitting the
relatively easy and fast removal and replacement of the clamp arms (58, 60) so
that the
clamp arms (58, 60) may be readily changed as needed to be compatible with the
pipe (22)
to be slotted by the apparatus (20).
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Each clamp (54) of the clamping system (40) may be comprised of any
structure, members or assembly capable of maintaining the stationary clamp arm
(58) in a
fixed position while permitting the movement of the movable clamp arm (60)
relative to the
stationary clamp arm (58) between the clamped and unclamped positions of the
clamping
assembly (40). In the preferred embodiment, each clamp (54) is comprised of at
least one
stationary clamp bracket (72), and preferably a plurality of stationary clamp
brackets (72),
associated with the stationary clamp arm (58). Further, in the preferred
embodiment, each
clamp (54) is comprised of at least one movable clamp bracket (74), and
preferably a
plurality of movable clamp brackets (74), associated with the movable clamp
arm (60).
Referring to Figure 1, either one of the stationary or the movable clamp
brackets (72, 74)
may be located nearer the cutting head (42) of the apparatus (20). However,
preferably, the
stationary clamp bracket (72) and the stationary clamp arm (58) associated
therewith are
positioned or located nearer the cutting head (42) in order to provide or
permit freer
movement of the movable clamp arm (60).
More particularly, refernng to Figures 3, 5 and 6, a plurality of stationary
clamp brackets (72) are fixedly or rigidly mounted, connected or otherwise
attached with
the upper surface (46) of the stationary pipe bed (38) adjacent the cutting
head (42).
Preferably, the stationary clamp brackets (72) are spaced apart longitudinally
along the
length of the stationary clamp arm (58) defined between the opposed side ends
(62). In the
preferred embodiment, four stationary clamp brackets (72) are rigidly secured
to the upper
surface (46) of the pipe bed (38) such that the stationary clamp brackets (72)
are spaced
apart between the opposed side ends (62) of the stationary clamp arm (58).
The stationary clamp arm (58) may be associated with the stationary clamp
brackets (72) in any manner and by any mechanism wherein the stationary clamp
brackets
(72) maintain a fixed position of the stationary clamp ann (58). However,
preferably, the
stationary clamp arm (58) is associated with the stationary clamp brackets
(72) in a mamler
and by a mechanism permitting the removal and replacement of the stationary
clamp arm
(58) from and to the stationary clamp brackets (72). In the preferred
embodiment, the
stationary clamp arm (58) is removably connected, mounted or attached with the
stationary
clamp brackets (72) by a releasable spring loaded pin system (76). The spring
loaded pin
system (76) is comprised of at least one clamp ann mounting member (78), and
preferably a
plurality of clamp arm mounting members (78), fixedly mounted with the outer
surface (70)
of the stationary clamp ann (58). In the preferred embodiment, four clamp ann
mounting
members (78) are fixedly mounted with the outer surface (70) such that the
clamp arm
mounting members (78) are spaced apart between the opposed side ends (62) of
the
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stationary clamp arm (58). Each clamp arm mounting member (78) preferably
includes
opposed mounting ends (80).
The spring loaded pin system (76) is further comprised of at least one
releasable spring loaded pin (80) extending between the stationary clamp arm
brackets (72)
for receipt within or extension through at least one of the mounting ends (80)
of the clamp
arm mounting member (78). In the preferred embodiment, two releasable spring
loaded
pins (80) extend between the stationary clamp arm brackets (72), wherein each
of the
mounting ends (80) of each clamp arm mounting member (78) are adapted for
receiving or
permitting the extension therethrough of one of the spring loaded pins (80).
Refernng to Figures 4 - 6, a plurality of movable clamp brackets (74) are
movably mounted, connected or otherwise attached with the stationary clamp
brackets (72).
Preferably, one movable clamp bracket (74) is movably mounted with each
stationary
clamp bracket (72). Accordingly, the movable clamp brackets (74) are spaced
apart
longitudinally along the length of the movable clamp arm (60) defined between
the opposed
side ends (62). In the preferred embodiment, four movable clamp brackets (74)
are
movably mounted with the four stationary clamp brackets (72). The movable
clamp
brackets (74) may be movably mounted with the stationary clamp brackets (72)
in any
manner and by any mechanism, members or structure permitting the movable clamp
brackets (74) and the movable clamp arm (60) associated therewith to move
relative to the
stationary clamp brackets (72) and the stationary clamp arm (58) associated
therewith
between the clamped and unclamped positions.
The movable clamp arm (60) may be associated with the movable clamp
brackets (74) in any manner and by any mechanism wherein movement of the
movable
clamp brackets (74) results in a corresponding movement of the movable clamp
arm (60).
Further, preferably, the movable clamp arm (60) is associated with the movable
clamp
brackets (74) in a manner and by a mechanism permitting the removal and
replacement of
the movable clamp arm (60) from and to the movable clamp brackets (74).
In the preferred embodiment, the movable clamp arm (60) is removably
connected, mounted or attached with the movable clamp brackets (74) by a
further
releasable spring loaded pin system (76) as described above for the stationary
clamp arm
(58). Again, the spring loaded pin system (76) is comprised of at least one
clamp arm
mounting member (78), and preferably a plurality of clamp arm mounting members
(78),
fixedly mounted with the outer surface (70) of the movable clamp arm (60). In
the
preferred embodiment, four clamp arm mounting members (78) are fixedly mounted
with
the outer surface (70) such that the clamp ann mounting members (78) are
spaced apart
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between the opposed side ends (62) of the movable clamp arm (60). Each clamp
arm
mounting member (78) preferably includes opposed mounting ends (80).
Further, the spring loaded pin system (76) is again comprised of at least one
releasable spring loaded pin (80) extending between the movable clamp arm
brackets (74)
for receipt within or extension through at least one of the mounting ends (80)
of the clamp
arm mounting member (78). In the preferred embodiment, two releasable spring
loaded
pins (80) extend between the movable clamp arm brackets (74), wherein each of
the
mounting ends (80) of each clamp arm mounting member (78) are adapted for
receiving or
permitting the extension therethrough of one of the spring loaded pins (80).
In the preferred embodiment, a lowermost releasable spring loaded pin (82)
of the spring loaded system (76) associated with the movable clamp arm (60)
extends
through each of the stationary clamp brackets (72) as well as the movable
clamp brackets
(74) in order to movably mount the movable clamp brackets (74) with the
stationary clamp
brackets (72). Thus, the movable clamp brackets (74) and the movable clamp arm
(60)
associated therewith may pivot about the lowermost releasable spring loaded
pin (82) to
move relative to the stationary clamp brackets (72) and the stationary clamp
arm (58)
associated therewith between the clamped and unclamped positions of the
clamping system
(40).
The movable clamp brackets (74) may be caused to pivot about the
lowermost releasable spring loaded pin (82) to move relative to the stationary
clamp
brackets (72) by any mechanism or structure capable of producing a controlled
motion such
that the clamping arms (58, 60) may engage the pipe wall (24) in the clamped
position with
a desired clamping pressure or force. Further, it is preferable that the
mechanism or
structure permit or provide for the locking or maintaining of the applied
clamping pressure
or force when the clamping system (40) is in the clamped position. This locked
clamping
pressure inhibits or precludes any movement of the clamping arms (58, 60)
during the
slotting of the pipe (22).
In the preferred embodiment, the clamping system (40) is further comprised
of at least one hydraulic cylinder (86) operatively connected with the movable
clamp arms
(60) of the clamping system (40) such that actuation of the hydraulic cylinder
(86) moves
the clamping system (40) between the clamped and unclamped positions. The
hydraulic
cylinder (40) is preferably connected with the movable clamp arms (60) of each
of the
plurality of clamps (54) comprising the clamping system (40) so that each of
the movable
clamp arms (60) is concurrently actuated by the hydraulic cylinder (86) for a
controlled and
consistent motion and application of the clamping pressure to the pipe wall
(24).
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The hydraulic cylinder (86) may be operatively connected with the movable
clamp arms (60) by any system of linkages therebetween. In the preferred
embodiment, the
clamping system (40) is comprised of a clamp rod (88) extending longitudinally
for
substantially the entire clamp length. The clamp rod (88) is actuated by the
hydraulic
cylinder (86) such that the clamp rod (88) is reciprocated longitudinally.
Further, the
clamping system (40) is comprised of at least one bracket rod (90) associated
with each
clamp (54), wherein the bracket rod (90) is mounted or connected between at
least two
adjacent movable clamp brackets (74). In the preferred embodiment, each clamp
(54)
includes two bracket rods (90) mounted or connected between adjacent movable
clamp
brackets (74).
Finally, the clamping system (40) is comprised of at least one linkage
member (92) for pivotally linking the clamp rod (88) with the at least one
bracket rod (90).
Thus, in the preferred embodiment, a plurality of linkage members (92) are
provided for
linking each of the plurality of bracket rods (90) with the clamp rod (88).
More
particularly, a first end (94) of the linkage member (92) is pivotally
connected with the
bracket rod (90), while a second end (96) of the linkage member (92) is
pivotally connected
with the clamp rod (88). Each of the first and second ends (94, 96) may be
pivotally
connected by a pin (98), bolt, screw or other suitable fastener with the
bracket rod (90) and
clamp rod (88) respectively. As a result, actuation of the hydraulic cylinder
(86)
longitudinally reciprocates the clamp rod (88) which is translated by the
linkage members
(92) into a pivoting movement to cause the movable clamp brackets (74) to
pivot about the
stationary clamp brackets (72) between the unclamped and clamped positions.
In the clamped position, the amount or level of the fluid within the hydraulic
cylinder (86) may be inhibited from leakage or otherwise maintained at a
desired level
within the hydraulic cylinder (86) in order to lock or maintain the clamping
pressure or
force being applied by the clamping system (40). Preferably, following
charging of the
hydraulic cylinder (86) with fluid, the cylinder valves (not shown) are closed
to prevent any
loss of fluid from the hydraulic cylinder (86). As the fluid within the
hydraulic cylinder
(86) is substantially incompressible, movement of the movable clamping arm
(60) towards
the unclamped position is inhibited or precluded during the slotting of the
pipe (22).
As indicated, the apparatus (20) is further comprised of the cutting head
(42). The cutting head (42) includes at least one cutter (100) for slotting
the pipe (22). In
the preferred embodiment, the cutting head (42) is comprised of a plurality of
cutters (100)
Therefore a plurality of slots (30) are formed in the pipe (22) by the
apparatus (20). The
cutters (100) are comprised of circular blades or saws in the preferred
embodiment.
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However, the cutters (100) may also use drill bits, laser cutting, gas
cutting, water cutting,
electronic discharge cutting or any other device, apparatus, mechanism or
method suitable
for, and compatible with, cutting the pipe (22) in the manner described
herein.
The cutters (100) are preferably linearly arranged along the cutting head (42)
in a row such that the row is substantially parallel to the longitudinal
clamping gap (52).
Thus, the cutters (100) are preferably linearly arranged along the cutting
head (42) in a row
substantially parallel to the longitudinal axis of the pipe (22) in the
clamped position on the
pipe bed (38). However, the cutters (100) may be arranged in any pattern or
configuration
suitable for, and compatible with, the particular pipe (22) being slotted and
the intended use
or application of the pipe (22).
More particularly, in the preferred embodiment, the cutting head (42) is
comprised of one or more, and preferably a plurality of, cutting boxes (114).
The cutting
boxes (114) are mounted adjacent to each other along the length of the cutting
head (42) as
shown in Figure 2. In the preferred embodiment, the cutting head (42) includes
twenty
cutting boxes (114), wherein each clamp (54) is matched with a corresponding
cutting box
(114). Referring to Figure 2, the discontinuous vertical line shows a break in
the length of
the apparatus (20), however, the structure provided on either side of the'
discontinuous line
is repeated for the length of the apparatus (20). Thus, although five cutting
boxes (114) are
shown therein, as stated above, the cutting head (42) includes twenty cutting
boxes (114) in
the preferred embodiment. Further, refernng to Figures 7 - 10, each cutting
box (114) is
comprised of, and contains, one or more cutters (100). In the preferred
embodiment, each
cutting box (114) includes four cutters (100). Thus, in the preferred
embodiment, the
cutting head (42) permits a total of eighty slots to be cut along the length
of the pipe (22) by
the cutting head (42).
Further, each cutting box (114) is associated with a power source for
operation of the cutters (100). In the preferred embodiment, the power source
is comprised
of a motor, preferably a hydraulic motor (116), mounted to the cutting box
(114) and
operatively connected to each cutter (100). Specifically, the motor (116)
operates the
cutters (100) by a two belt (118) pulley system, wherein the belts (118) are
arranged
between the motor (116) and the cutters (100), as shown in Figure 10. In the
preferred
embodiment, the cutters (100) may be rotated in one or both directions by the
motors (116).
Specifically, during slotting of the pipe (22) by the cutters (100), a number
of the cutters
(100) will typically be rotated in one direction, while a number of the
cutters (100) are
concurrently rotated in the opposite direction. In this manner, any unwanted
horizontal
movement of the cutters (100) is further inhibited or minimized.
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As shown in Figures 7 and 8, the motor (116) is fixedly mounted to a
mounting plate (120) by bolts or other suitable fasteners. The plate (120) is
then adjustably
mounted to the cutting box (114) by four adjustable screws (122). The
adjustment of the
adjustable screws (122) permits the loosening and tightening of the belts
(118), as well as
the proper alignment of the belts (118). Activation of the motor (116) causes
rotation of a
motor pulley (124).
Each cutter (100) includes a spindle (126), having a front end (128) and a
back end (130). The front and back ends (128, 130) of each spindle (126)
extend through
the cutting box (114) and are supported in the cutting box (114) by bearing
and seal
assemblies (132). Each spindle (126) is held in position in the cutting box
(114) by
adjusting both bearing and seal assemblies (132). Further, the back end (130)
of each
spindle (126) includes a spindle pulley (134). Referring to Figure 10, each of
the two belts
(118) is mounted about the motor pulley (124) and two spindle pulleys (134).
Thus, two
belts (118) are able to operate all four spindle pulleys (134).
Further, a cog wheel (not shown) may be mounted to the back end (130) of
the spindle pulley (134) of one spindle (126) in the cutting box (114). Thus,
only one cog
wheel is located on each cutting box (114). The cog wheel (not shown) is
contained within
a sensor or counter (not shown) wluch is attached to the bearing and seal
assembly (132) on
the spindle (126). The sensor or counter (not shown) is designed to count the
teeth of the
cog wheel as the cog wheel is rotated by the spindle (126). The data from the
counting of
the teeth may be sent to a computer system, as described further below, in
order to calculate
and determine the rotations per minute (rpm) of the spindle (126). In
operation, each of the
four spindles (126) in a cutting box (114) will rotate at the same rpm.
However, the rpm
may tend to vary between cutting boxes (114). The information sent to the
computer
system by the cog wheel may therefore be used to adjust the flow of the
hydraulic fluid to
the hydraulic motors (116) of the various cutting boxes (114) in order to
synchronize the
rpm of all cutting boxes (114), to ensure that all cutter blades (144) are
running at
approximately the same rpm.
Referring to Figure 9, the front end (128) of each spindle (126) includes a
tapered portion (136). An arbor (138), spindle connector or other suitable
connector,
having a tapered portion (140) complimentary to the tapered portion (136) of
the spindle
(126), is mounted to the front end (128) of the spindle (126). Thus, the
diameter of the
tapered portion (140) of the arbor (138) is sized to fit onto the outside
diameter of the
tapered portion (136) of the front end (128) of the spindle (126). A nut (142)
or other
suitable fastening means is used to connect the arbor (138) to the spindle
(126).
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Specifically, the nut (142) extends through the arbor (138) and screws onto
the front end
(128) of the spindle (126). Thus, the arbor (138) is held in position.
As indicated, the arbor (138) includes a tapered portion (140) at one end
thereof. The opposite end of the arbor (138) is operatively connected to a
cutter blade
(144). In the preferred embodiment, the end of the arbor (138) to be connected
to the blade
(144) includes a threaded portion (146) and an adjacent keyway cut (148). The
blade (144)
defines an opening for the mounting of the blade (144) on the arbor (138).
Specifically, the
end of the arbor (138) is inserted through the opening in the blade (144)
until such time that
the blade (144) is located within the keyway cut (148). One or more spacers
(150) are also
located within the keyway cut (148) in order to secure the blade (144) therein
and inhibit
rotation of the blade (144) on the spindle (126). The spacers (150) and the
blade (144) are
tightened and held into position by an arbor nut (152) which is threaded onto
the threaded
portion (146) of the arbor (138). Different sizes of spacers (150) are used to
ensure that the
centre of any particular blade (144) is aligned with the top dead centre line
of the pipe, in
the preferred embodiment.
As indicated, in the preferred embodiment, a single blade (144) is mounted
upon each spindle (126) in the manner described above. However, more than one
blade
(144) may be mounted to each spindle (126) where desirable for a particular
application.
For instance, two or more blades (144) may be mounted on the spindle (126) a
spaced
distance apart in order that greater than one row of slots (30) may be cut
concurrently or
simultaneously.
The cutting box (114) may also include a sensor or proximity switch (154),
as shown in Figure 7, which is mounted to a bracket (156), which is in turn
mounted to the
bearing and seal assembly (132) at the front end (128) of one of the spindles
(126). The
proximity switch or sensor (154) relays a message to the computer system
confirming the
presence of a blade (144) at the front end (128) of the spindle (126). In
other words, the
proximity switch or sensor (154) works in relationship to the blade (144)
itself. Thus, if a
blade (144) breaks, the proximity switch or sensor (154) can relay a message
to the
computer identifying the breakdown of the blade (144). Thus, the proximity
switch or
sensor (154) provides a safety feature to the apparatus (20).
The slots (30) cut in the pipe wall (24) may have any desired slot width and
any desired slot length. For instance, typically, conventional apparatuses are
capable of
cutting slots having a slot length of between 1.5 inches (3.81 cm) and 2.5
inches (6.35 cm).
The apparatus (20) permits the cutting of slots (30) having such typical slot
lengths,
however, the apparatus (20) further permits the cutting of slots (30) having a
slot length of
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greater than 2.5 inches (6.35 cm) to a maximum of about 12 inches (30.48 cm).
Thus, in
the preferred embodiment, the apparatus (20) permits the cutting of slots (30)
having a slot
length of between about 1.5 inches (3.81 cm) and 12 inches (30.48 cm).
Further, in the
preferred embodiment, the slot width is between about 0.008 inches (0.02032
cm) and
0.250 inches (0.635 cm). However, the specific configuration of the cutting
head (42), the
particular blade (144) being used and the distance between the centre line of
each blade
(144) or spindle (126) may be varied as required for the particular
application or pipe (22)
to be slotted. For instance, additional blades (144) may be added or every
second blade
(144) may be removed to permit shorter or longer slots (30) to be cut in the
pipe (22). In
the preferred embodiment, the cutting head (42) is able to move
longitudinally, as described
below, for a distance of about twelve inches (30.48 cm).
In addition, the apparatus (20) includes a precise motion control system
which includes three independent systems or mechanisms: a first perforating
mechanism; a
second longitudinal moving mechanism; and a third indexing mechanism. Each of
the
first, second and third mechanisms (158, 160, 162) is preferably operable
independently
from the others and performs its function in sequence with the others. The
relatively
precise control provided by these independent mechanisms permits variable
slotting
patterns to be cut in the pipe (22) having both precise and consistent slot
(30) dimensions or
geometries.
The first perforating mechanism (158), preferably operable independently
from the second and third mechanisms (160, 162), provides for precise control
over the
elevation of the cutting head (42). More particularly, the first perforating
mechanism (158)
moves the cutting head (42) toward and away from the longitudinal clamping gap
(52) such
that the pipe wall (24) is perforated by the cutters (100) through the
longitudinal clamping
gap (52) at a location of contact between the cutters (100) and the pipe wall
(22).
The second longitudinal cutting mechanism (160), preferably operable
independently from the first and third mechanisms (158, 162), provides for
precise control
over the translation of the cutting head (42) and thus the slot length. More
particularly, the
second longitudinal cutting mechanism (160) moves the cutting head (42)
longitudinally
relative to the pipe bed (38) along the longitudinal clamping gap (52) such
that the
perforated pipe wall (24) is fixrther cut by the cutters (100) through the
longitudinal
clamping gap (52) to form a plurality of discrete slots (30), each of the
slots (30) having a
slot length.
The third indexing mechanism (162), preferably operable independently
from the first and second mechanisms (158, 160), provides for precise control
over the
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rotation of the pipe (22). More particularly, the third indexing mechanism
(162) rotates the
pipe (22)J about the pipe longitudinal axis when the clamping system (40) is
in the
unclaznped position such that the location of contact between the cutters
(100) and the pipe
wall (24) is varied about the pipe circumference.
The first perforating mechanism (158) may be comprised of any suitable
apparatus, mechanism, device or structure capable of performing the required
function
described above, and specifically, capable of moving the cutting head (42)
toward and away
from the longitudinal clamping gap (52) in the manner and for the purposes
described
herein.
The first perforating mechanism (158) preferably moves the cutting head
(42) so that the longitudinal axis of the cutting head (42) is substantially
parallel to the
longitudinal axis of the pipe (22) in the clamped position. Accordingly, the
cutters (100)
preferably concurrently or simultaneously form each of the slots (30) in the
row in the pipe
wall (24). As well, the row of slots (30) is thus formed substantially
parallel to the
longitudinal axis of the pipe (22). However, where suitable for, and
compatible with, the
particular pipe (22) being slotted and the intended use or application of the
pipe (22), the
longitudinal axis of the cutting head (42) may be other than parallel to the
longitudinal axis
of the pipe (22), provided the cutters (100) are able to perforate the pipe
wall (24) through
the longitudinal clamping gap (52), so that the row of slots (30) may be
formed along the
pipe (22) other than parallel to its longitudinal axis.
In the preferred embodiment, the cutters (100) also preferably contact the
uppermost part of the pipe (22), or the top dead centre line of the pipe (22),
such that the
row of slots (30) is formed thereon. However, the specific configuration and
structural
relationship of the cutting head (42) and the pipe bed (38) may be varied as
desired for any
particular application such that the cutters (100) may contact the pipe wall
(24) and form
the slots (30) at any other location about the pipe circumference.
In the preferred embodiment, the first perforating mechanism (158) is
comprised of the movable frame (44) for supporting the cutting head (42)
adjacent to the
pipe bed (38), a carriage (164) for supporting the movable frame (44) and a
gear assembly
(166) operatively associated with the carriage (164). More particularly,
referring to Figures
1 and 2, the movable frame (44) supports the cutting head (42) adjacent the
pipe bed (38)
such that the row of cutters (100) is movable towards and away from the
longitudinal
clamping gap (52). In other words, movement of the movable frame (44) moves
the row of
cutters (100) either towards or away from the longitudinal clamping gap (52)
in order to
move the cutters (100) into and out of contact with the pipe wall (24). In the
preferred
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embodiment, the location of contact between the cutters (100) and the pipe
wall (24) is at
the top dead centre line of the pipe (22). Further, the movable frame (44)
preferably
supports the cutting head (42) such that the row of cutters (100) is movable
substantially
vertically towards and away from the longitudinal clamping gap (52), which is
positioned at
the top dead centre of the pipe (22), in order to perforate the pipe wall (24)
with the cutters
( 100).
Thus, the movable frame (44) is movable in a manner and a direction such
that the row of cutters (100) is preferably moved substantially vertically. In
the preferred
embodiment, the movable frame (44) is movable in a substantially vertical
plane such that
vertical movement of the movable frame (44) results in a corresponding
vertical movement
of the cutting head (42) supported thereon. The cutting head (42) may be
supported by the
movable frame (44) in any manner and by any mechanism or structure permitting
the
corresponding movement of the movable frame (44) and the cutting head (42).
The movable frame (44) may be comprised of a single member or element or
a plurality of members or elements connected or mounted together to provide
the complete
movable frame (44). In the preferred embodiment, the movable frame (44) is
comprised of
at least one upper member (168) having an upper surface (168) for supporting
the cutting
head (42) thereon. Further, the movable frame (44) is comprised of at least
one and
preferably a plurality of lower members (172), each having a lower surface
(174) associated
with the carriage (164). The upper member (168) is preferably fixedly
supported upon or
mounted with the lower member (172) such that movement therebetween is
inhibited or
precluded. In addition, the movable frame (44) preferably extends
longitudinally adjacent
the pipe bed (38) for substantially the entire pipe bed length in order to
fully support the
length of the cutting head (42) thereon.
The carriage (164) is provided for supporting the movable frame (44)
thereon. Although any portion of the movable frame (44) may be supported by
the carnage
(164), the carriage (164) is preferably associated with each of the lower
members (172) of
the movable frame (44) and more particularly, the lower surfaces (174).
Further, the
carnage (164) supports the movable frame (44) such that the carriage (164) is
movable
longitudinally relative to the pipe bed (38). More particularly, the carriage
(164) may be
associated with the movable frame (44) in any manner and by any mechanism or
structure
such that the longitudinal movement of the carnage (164) relative to the pipe
bed (38)
causes or results in the movement of the cutters (100) either towards or away
from the
longitudinal clamping gap (52) as described above. In the preferred
embodiment, the
longitudinal movement of the carriage (164) is translated into the movement of
the cutting
head (42) and the cutters (100).
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In the preferred embodiment, the carriage (164) is movable longitudinally
adjacent the pipe bed (38) in a substantially horizontal plane. This
longitudinal horizontal
movement of the carriage (164) is translated into the movement of the movable
frame (44)
in a substantially vertical plane, wherein the vertical movement of the
movable frame (44)
results in a corresponding vertical movement of the cutting head (42)
supported thereon.
Any structure or mechanism may be provided permitting the longitudinal
movement or sliding of the carriage (164) adjacent the pipe bed (38).
Referring to Figures
1 and 2, in the preferred embodiment, the carriage (164) is slidably or
movably mounted
upon or with the stationary frame (36) of the apparatus (20). More
particularly, a plurality
of bearings (175) are positioned between the carriage (164) and the stationary
frame (36) to
facilitate the reciprocating longitudinal movement of the carnage (164)
relative to the
stationary frame (36).
The bearings (175) may be comprised of any type of bearings or bearing
structure compatible with and suitable for the intended function. For
instance, one or more
elongate rails (not shown) may be fastened along the stationary frame (36)
adjacent the pipe
bed (38) for substantially the entire pipe bed length. Similarly, a plurality
of bearing boxes
(not shown) may be fastened along the lowermost surface of the carriage (164)
adjacent the
stationary frame (36). The plurality of bearing boxes are then slidably
mounted on each rail
such that the bearing boxes are permitted to slide horizontally thereon along
the length of
the rails.
Further, any structure or mechanism may be provided for translating the
horizontal movement of the carriage (164) into the vertical movement of the
movable frame
(44). In the preferred embodiment, the first perforating mechanism (158) is
further
comprised of at least one and preferably a plurality of wedge-shaped brackets
(176).
Preferably, one wedge-shaped bracket (176) is positioned between the carnage
(164) and
the lower surface (174) of each lower member (172) of the movable frame (44).
More particularly, each wedge-shaped bracket (176) has a lower surface
(178) and an upper surface (180). The lower surface (178) is fixedly mounted,
attached or
connected with the carriage (164) such that the longitudinal reciprocating
movement of the
carnage (164) relative to the pipe bed (38) causes a corresponding
longitudinal
reciprocating movement of the wedge-shaped bracket (176). The upper surface
(180) of
each wedge-shaped bracket (176) is sloped to form the wedge-shape of the
bracket (176).
The lower surface (174) of each lower member (172) of the movable frame (44)
is similarly
provided with a slope compatible with and corresponding to the slope of the
upper surface
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(180) of the wedge-shaped bracket (176), as shown in Figure 2. Accordingly, in
the
preferred embodiment, the longitudinal horizontal movement of the carriage
(164) is
translated into the vertical movement of the movable frame (44) by the
engagement of the
correspondingly sloped upper and lower surfaces (180, 174) of the wedge-shaped
bracket
(176) and lower member (172) respectively.
Preferably, a plurality of bearings (175) are positioned between the sloped
upper and lower surfaces (180, 174) of the wedge-shaped bracket (176) and
lower member
(172) respectively to facilitate the sliding movement therebetween. Again, the
bearings
(175) may be comprised of any type of bearings or bearing structure compatible
with and
suitable for the intended function. For instance, one or more elongate rails
(not shown) may
be fastened along the sloped upper surface (180) of the wedge-shaped bracket
(176). A
plurality of bearing boxes (not shown) may be fastened along the sloped lower
surface
(174) of the lower member (172). The plurality of bearing boxes are then
slidably mounted
on each rail such that the bearing boxes are permitted to slide thereon along
the length of
the rails.
Further, a plurality of bearings (175) may be associated with each of the
lower members (172) of the movable frame (44) along at least one side surface
(182) for
directing and facilitating the movement of the lower member (172) in a
substantially
vertical plane. More particularly, a plurality of vertical linear bearings
(175) are preferably
associated with at least one side surface (182) of each lower member (172) to
direct and
cause the movable frame (44), and thus the cutting head (42), to move in a
substantially
vertical direction. The bearings (175) may be comprised of any type of
bearings or bearing
structure compatible with and suitable for the intended function.
Finally, the first perforating mechanism (158) is comprised of a mechanism
or device for moving the carnage (164) longitudinally. Although the carriage
(164) may be
moved longitudinally by any mechanism, structure or device capable of causing
the desired
longitudinal movement, preferably, the first perforating mechanism (158) is
comprised of
the gear assembly (166). Any gear assembly (166) operatively connected with
the carnage
. (164) to longitudinally move the carriage (164) may be used. However, in the
preferred
embodiment, the gear assembly (166) is comprised of a rack and worm gear
system.
More particularly, the gear assembly (166) is comprised of a rack (184)
operatively connected with the carriage (164) such that movement of the rack
(184)
longitudinally moves the carriage (164). In the preferred embodiment, the rack
(184) is
connected or mounted with an end of the carnage (164), preferably adjacent the
back end
(34) of the apparatus (20). Further, the gear assembly (166) is comprised of a
worm (186).
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The worm (186) drivingly engages the rack (184) such that rotation of the worm
(186)
moves the rack (184) and thus the carnage (164) longitudinally. Rotation of
the worm
(186) in a first direction reciprocates the carriage (164) in a first
direction causing the
cutting head (42) to move vertically upwards such that the cutters (100) are
moved away
from the longitudinal clamping gap (52). Rotation of the worm (186) in an
opposed second
direction reciprocates the carriage (164) in an opposed second direction
causing the cutting
head (42) to move vertically downwards such that the cutters (100) are moved
towards the
longitudinal clamping gap (52).
The worm (186) is actuated by a gear box (188) and a motor (190).
Although any suitable motor (190) may be used, the motor (190) is preferably a
variable
speed electric motor. In the preferred embodiment, the gear box (188) and the
motor (190)
are mounted or connected with the stationary frame (36), preferably adjacent
the back end
(34) of the apparatus (20). The preferred embodiment of the gear assembly
(166) permits or
provides for a controlled, gradual and relatively precise movement of the
first perforating
mechanism (158). More particularly, precise controlled movement of the carnage
(164)
horizontally by the rack (184) and worm (186) results in a precise controlled
vertical
movement of the cutting head (42). As a result, the speed and precision with
which the
cutters (100) perforate the pipe wall (24) may also be closely controlled
during the slotting
of the pipe (22).
The second longitudinal cutting mechanism (160) may be comprised of any
suitable apparatus, mechanism, device or structure capable of performing the
required
function described above, and specifically, capable of moving the cutting head
(42)
longitudinally relative to the pipe bed (38) along the longitudinal clamping
gap (52) in the
manner and for the purposes described herein. However, in the preferred
embodiment of
the apparatus (20), the second longitudinal cutting mechanism (160) will cause
a
substantially horizontal movement of the cutting head (42).
More particularly, the second longitudinal cutting mechanism (160) moves
the cutting head (42) longitudinally relative to the pipe bed (38) along the
longitudinal
clamping gap (52) for a distance such that the perforated pipe wall (24) is
further cut by the
cutters (100) through the longitudinal clamping gap (52) to form a plurality
of discrete slots
(30), each of the slots (30) having a slot length. The movement of the cutting
head (42) for
a distance selected by the operator of the apparatus (20) results in the
formation of slots (30)
having a desired slot length. In this case, the length of the slots (30) will
not be solely
determined or controlled by the size, shape or type of cutters (100) used in
the cutting head
(42). More specifically, where the cutters (100) include a blade or circular
saw, the length
of the slot (30) will not be solely determined or controlled by the diameter
of the blade.
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The second longitudinal cutting mechanism (160) is operatively connected
with the cutting head (42) to move the cutting head (42) relative to the
stationary pipe bed
(38) along the longitudinal clamping gap (52). Thus, in the preferred
embodiment,
following the perforation of the pipe wall (24) by the cutters (100) as a
result of the
substantially vertical movement of the cutting head (42) by operation of the
first perforating
mechanism (158), the second longitudinal cutting mechanism (160) causes the
cutting head
(42) to move substantially horizontally such that the cutters (100) cut the
pipe wall (24) to
form the slots (30) therein. When the cutters (100) are not in contact with
the pipe wall
(24), the second longitudinal cutting mechanism (160) permits the contact
location between
the pipe (22) and the cutters (100) to be varied longitudinally along the pipe
(22).
The ability of the apparatus (20) to move the cutting head (42) longitudinally
by the second longitudinal cutting mechanism (160) may give rise to several
advantages of
the apparatus (20), as compared to conventional casing Blotters. For instance,
the length of
the slots (30) may no longer be primarily or solely determined or controlled
by the type and
size of cutters (100) used in the apparatus (20), and in particular, by the
diameter of the
circular cutting blade. Accordingly, a smaller diameter blade, having greater
stability as
compared to larger blades, may be used. As a result, blade breakage may be
reduced and
cutting speeds may be increased. As well, the apparatus (20) may allow for
greater control
of slot width deviation and may allow for relatively narrower or finer slot
widths to be cut
in conventional casing, as compared to conventional casing Blotters, thus
obviating the need
for wire wrapped casing.
By increasing the length of the slot (30) and keeping the open flow area of
the slot (30) constant, the cross sectional area removed by the slotting
process will be
decreased. This may increase both the tensile and torsional strength of the
pipe (22): If the
strength of the pipe (22) is kept consistent with a comparable slotted liner
produced by
conventional casing Blotters, the cross sectional area removed by the slotting
process would
remain the same but the open flow area of the slot (30) may be increased. This
increased
open flow area may result in an increased production through the pipe (22). If
the open
flow area is kept consistent with a comparable slotted liner produced by
conventional
casing slotters, the cost of producing the slotted pipe (22) may be reduced by
increasing the
slot length and decreasing the amount of rows cut.
In the preferred embodiment, the cutting head (42) is mounted or supported
upon the movable frame (44) in a manner and by any mechanism or structure
permitting the
longitudinal movement of the cutting head (42) as described above. As
previously
discussed, in the preferred embodiment, the cutting head (42) is preferably
supported upon
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the upper surface (170) of the upper member (168) of the movable frame (44)
such that
vertical movement of the movable frame (44) vertically moves the cutting head
(42). In
addition, in the preferred embodiment, the cutting head (42) is supported on
the upper
surface (170) by a mechanism permitting the substantially horizontal
reciprocating
movement of the cutting head (42) longitudinally thereon.
The cutting head (42) may be slidably or movably mounted with the
movable frame (44) in any manner and by any mechanism or structure permitting
the
necessary movement of the cutting head (42) as described above. In the
preferred
embodiment, the lowermost surfaces of each of the cutting boxes (114) comprise
a lower
surface (192) of the cutting head (42). The lower surface (192) of the cutting
head (42) is
slidable or movable along the upper surface (170) of the upper member (168) of
the
movable frame (44). Preferably, a plurality of bearings (175) are positioned
between the
adjacent lower and upper surfaces (192, 170) of the cutting head (42) and the
upper member
(168) respectively to facilitate the sliding movement therebetween.
The bearings (175) may be comprised of any type of bearings or bearing
structure compatible with and suitable for the intended function. For
instance, one or more
elongate rails (not shown) may be fastened along the upper surface (170) of
the upper
member (168) of the movable frame (44). A plurality of bearing boxes (not
shown) may be
fastened along the lower surface (192) of the cutting head (42). The plurality
of bearing
boxes are then slidably mounted on each rail such that the bearing boxes are
permitted to
slide thereon along the length of the rails.
The second longitudinal cutting mechanism (160) may be comprised of any
mechanism or device capable of longitudinally moving the cutting head (42)
along the
bearings (175) in the previously described direction. However, preferably, the
second
longitudinal cutting mechanism (160) is also comprised of a gear assembly
(194) similar to
the gear assembly (166) previously described for the first perforating
mechanism (158).
Any gear assembly (194) operatively connected with the cutting head (42) to
longitudinally
move the cutting head (42) may be used. However, in the preferred embodiment,
the gear
assembly (194) is comprised of a rack and worm gear assembly.
More particularly, the gear assembly (194) is comprised of a rack (196)
operatively connected with the cutting head (42) such that movement of the
rack (196)
longitudinally moves the cutting head (42). In the preferred embodiment, the
rack (196) is
connected or mounted with an end of the cutting head (42), preferably adjacent
the back end
(34) of the apparatus (20). Further, the gear assembly (194) is comprised of a
worm (198).
The worm (198) drivingly engages the rack (196) such that rotation of the worm
(198)
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moves the rack (196) and thus the cutting head (42) longitudinally. Rotation
of the worm
(198) in a first direction reciprocates the cutting head (42) relative to the
pipe bed (38)
horizontally in a first direction along the longitudinal clamping gap (52).
Rotation of the
worm (198) in an opposed second direction reciprocates the cutting head (42)
relative to the
pipe bed (38) horizontally in an opposed second direction along the
longitudinal clamping
gap (52).
The worm (198) is actuated by a gear box (200) and a motor (202).
Although any suitable motor (202) may be used, the motor (202) is preferably a
variable
speed electric motor. In the preferred embodiment, the gear box (200) and the
motor (202)
are mounted or connected with the upper member (168) of the movable frame
(44),
preferably adjacent the back end (34) of the apparatus (20). The preferred
embodiment of
the gear assembly (194) permits or provides for a controlled, gradual and
relatively precise
movement of the cutting head (42) by the second longitudinal cutting mechanism
(160).
More particularly, precise controlled movement of the cutting head (42)
horizontally by the
rack (196) and worm (198) results in a precise controlled horizontal movement
of the
cutters (100) to from the slots (30) with precision in the pipe wall (24) to
ensure accurate
slot (30) geometry and configuration.
Further, the apparatus (20) is also preferably comprised of the third indexing
mechanism (162) for rotating the pipe (22) about its longitudinal axis when
the clamping
system (40) is in the unclamped position. As a result, the location of contact
between the
cutters (100) and the pipe wall (24) may be varied about the pipe
circumference. The third
indexing mechanism (162) permits the location of contact between the cutters
(100) and the
pipe wall (24) to be varied 360 degrees about the pipe circumference.
Therefore, any
number of rows of slots (30), as desired, may be cut. The combination of the
first
perforating mechanism (158), the second longitudinal cutting mechanism (160)
and the
third indexing mechanism (162) allows the apparatus (20) to cut a broad range
of slot
patterns in the pipe (22) to suit the particular needs of the pipe (22) for a
specific use or
application.
Although the third indexing mechanism (162) may be positioned at any
location along the pipe length, referring to Figure 2, the third indexing
mechanism (162) is
preferably associated with the stationary frame (36) adjacent an end of the
apparatus (20),
preferably the front end (21). Accordingly, when the pipe (22) is supported by
the pipe bed
(38) in the unclamped position, an end of the pipe (22) may be secured by the
third
indexing mechanism (162).
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The third indexing mechanism (162) may be comprised of any suitable
mechanism, device or structure capable of performing the required function or
purpose of
the rotating the pipe (22) about its longitudinal axis as described herein.
However, referring
to Figures 11 and 12, in the preferred embodiment, the third indexing
mechanism (162) is
comprised of an outer plate (204) mounted or fixedly supported by a lower
frame member
(205) in a desired position adjacent the front end (21) of the apparatus (20).
Further, the
third indexing mechanism (162) is comprised of a rotatable head (206)
rotatably mounted to
or within the outer plate (204). The rotatable head (206) releasably secures
the pipe (22)
such that rotation of the rotatable head (206) rotates the pipe (22) about the
pipe
longitudinal axis.
In the preferred embodiment, the rotatable head (206) defines an opening
(208) for receiving an end of the pipe (22). The pipe (22) may be releasably
secured within
or to the opening (208) by any suitable fastening or clamping mechanism or
device capable
of releasably engaging the pipe (22) in a relatively secure manner to permit
the rotatable
head (206) to rotate the pipe (22). In the preferred embodiment, referring to
Figure 11, the
fastening or clamping mechanism is comprised of a hollow spindle chuck (209)
positioned
or mounted within the opening (208) of the rotatable head (206) for clamping
or fastening
to the end of the pipe (22). Clamping of the chuck (209) to the end of the
pipe (22) securely
engages the pipe wall (24), while releasing the clamping of the chuck (209)
from the pipe
wall (24) permits removal of the end of the pipe (22) therefrom. The chuck
(209) is
preferably adjustable in order to accommodate varying pipe circumferences.
Referring to Figure 11, in the preferred embodiment, the chuck (209)
includes three jaws (211) spaced about the circumference of the opening (208).
Operation
of a mechanical screw (213) causes the jaws (211) to extend into the opening
(208) to
securely engage the pipe wall (24) or to retract from the opening (208) to
release the pipe
wall (24). The jaws (211) are adjustable in order to acconunodate varying pipe
circumferences. Further, the engagement end of each jaw (211) may include a
plurality of
gripping teeth thereon for enhancing the engagement with the pipe surface (24)
in the
extended position.
The third indexing mechanism (162) may be comprised of any mechansm or
device capable of rotating the rotatable head (206) within the outer plate
(204). However,
preferably, the third indexing mechanism (162) is comprised of a gear assembly
(210). Any
gear assembly (210) operatively connected with the rotatable head (206) to
rotate the
rotatable head (206) may be used. However, in the preferred embodiment, the
gear
assembly (210) is comprised of a worm gear - gear assembly.
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More particularly, the rotatable head (206) is preferably comprised of a gear
wheel (212) or a worm wheel. Further, the third indexing mechanism (162) is
comprised of
a worm (214) operatively associated with the gear wheel (212) such that
rotation of the
worm (214) actuates the gear wheel (212) to cause the rotation of the
rotatable head (206)
within the outer plate (204). In the preferred embodiment, the worm (214) is
mounted or
supported in position for engaging the gear wheel (212) by an upper frame
member (216) of
the third indexing mechanism (162). The upper frame member (216) is mounted or
fixedly
supported by the outer plate (204).
Thus, the worm (214) drivingly engages the gear wheel (212) such that
rotation of the worm (214) actuates the gear wheel (212) to rotate the
rotatable head (206).
Rotation of the worm (214) in a first direction rotates the rotatable head
(206) and thus the
pipe (22) in a first direction about the pipe longitudinal axis. Rotation of
the worm (214) in
an opposed second direction rotates the rotatable head (206) and thus the pipe
(22) in an
opposed second direction about the pipe longitudinal axis.
Further, the worm (214) is actuated by a gear box (218) and a motor (220).
Although any suitable motor (220) may be used, the motor (220) is preferably a
variable
speed electric motor. In the preferred embodiment, the gear box (218) and the
motor (220)
are mounted or connected with the upper frame member (216). The preferred
embodiment
of the gear assembly (210) permits or provides for a controlled, gradual and
relatively
precise rotational movement of the rotatable head (206) by the third indexing
mechanism
(162). More particularly, precise controlled rotational movement of the
rotatable head
(206) by the worm (214) and gear wheel (212) results in precise and consistent
or uniform
spacing of the slots (30) about the pipe circumference. The particular
tolerances between
the worm (214) and gear wheel (212) may be selected to minimize backlash and
enhance
precision indexing of the pipe (22).
As well, the apparatus (20) may include a fourth mechanism (not shown) for
rotating the pipe wall (24) about the location of contact between the pipe
wall (24) and the
cutters (100). For instance, in the preferred embodiment, the location of
contact between
the pipe (22) and the cutters (100) is along the top dead centre of the pipe
(22). Thus, the
pipe (22) may be offset a given percentage about the top dead centre of the
pipe (22) to
allow the cutting of angled straight slots and keystone slots. The fourth
mechanism may be
comprised of any suitable mechanism, device or structure capable of performing
the
required function or purpose of rotating the pipe wall (24) about the location
of contact
between the pipe wall (24) and the cutters (100).
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The apparatus (20) is further comprised of a power source (not shown) for
driving or operating the various components of the apparatus (20).
Specifically, various
components of the apparatus (20), such as the clamping system (40), are
hydraulically
activated. Therefore, the power system or power source is comprised of a
hydraulic unit for
supplying and circulating oil to the required hydraulic motors and hydraulic
cylinders in the
apparatus (20), as described above. Further, the apparatus (20) includes a
number of
electrical motors, as described above. Therefore, the power source is further
comprised of a
motor control cabinet containing motor controls for operating the various
functions of the
apparatus (20) such as rpm, penetration rates, cutting rates, clamping and the
like., as well
as for supplying power to any electrical motors in the apparatus (20).
Finally, the apparatus (20) preferably includes a computer-aided machinery
or CAM system which controls the various functions of the apparatus (20). The
CAM
system includes a computer monitor and control station (not shown) where
information and
instructions, such as the rpm, penetration rate, numing rate, indexing, and
the other
operations of the apparatus (20), may be entered and monitored. The CAM system
will be
controlled and programmed by the operator of the apparatus (20). To aid the
operator in the
use of the CAM system, the monitor and control station of the CAM system is
preferably
allowed to move along one side of the apparatus (20) to any position. This
movement
allows the operator to walk along the side of the apparatus (20) with the
monitor and
control station while viewing the apparatus (20), including the operation of
the cutting head
(42). In the event of a blade (144) failure or other apparatus (20) breakdown,
the operator
may slide the monitor and control station to the area requiring work. The
operator will thus
be able to control and monitor the apparatus (20) at any required location
during startup of
the apparatus (20), continued operation of the apparatus (20) or shut down.
The invention is further directed at a method for slotting the pipe (22).
Preferably, the method is performed utilizing the apparatus (20) as described
herein.
However, any suitable apparatus capable of performing the method may
alternatively be
used.
The method is comprised of the step of positioning the pipe (22) on a
stationary pipe bed (38) and moving a clamping system (40) associated with the
pipe bed
(38) to a clamped position to releasably secure the pipe (22) to the pipe bed
(38). The
clamping system (40) is preferably comprised of a clamping surface (50)
adapted to engage
the pipe wall (24) in the manner described above for the apparatus (20).
Further, the
clamping system (40) preferably defines a longitudinal clamping gap (52) in
the clamped
position oriented to permit the slotting of the pipe (22) therethrough. In the
preferred
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embodiment of the method, the pipe (22) is preferably releasably secured in
the clamped
position such that the longitudinal axis of the pipe (22) is substantially
horizontal.
Further, in the method, the clamping surface (50) is adapted to engage in the
clamped position at least about 50 percent of the pipe circumference and at
least about 50
percent of the pipe length. The specific percent of the pipe circumference and
the pipe
length to be engaged by the clamping surface (50) may each be increased above
50 percent
as required to securely engage the pipe (22). For instance, the clamping
surface (50) may
be adapted to engage at least about 70 percent of the pipe circumference in
the clamped
position or at least about 90 percent of the pipe circumference in the clamped
position. In
the preferred embodiment, the clamping surface (50) is adapted to engage at
least about 95
percent of the pipe circumference in the clamped position. Further, the
clamping surface
(50) may be adapted to engage at least about 70 percent of the pipe length in
the clamped
position. In the preferred embodiment, the clamping surface (50) is adapted to
engage at
least about 90 percent of the pipe length in the clamped position.
The method is further comprised of the step of providing a movable cutting
head (42) at a location adjacent to the pipe bed (38). The cutting head (42)
is comprised of
a plurality of cutters (100) for slotting the pipe (22). Further, the cutters
(100) are linearly
arranged along the cutting head (42) in a row substantially parallel to the
longitudinal
clamping gap (52).
In addition, the method is comprised of the step of first moving the cutting
head (42) in a direction toward the longitudinal clamping gap (52) to move the
cutters (100)
into engagement with the pipe wall (24) such that the pipe wall (24) is
perforated by the
cutters (100) through the longitudinal clamping gap (52) at a location of
contact between
the cutters (100) and the pipe wall (24). In the preferred embodiment, the
first moving step
moves the cutting head (42) substantially vertically or in a vertical plane to
contact the
cutters (100) with the pipe wall (24), preferably such that the location of
contact is top dead
centre of the pipe (22). Accordingly, the longitudinal clamping gap (52) in
the clamped
position of the clamping system (40) is positioned or oriented to permit the
slotting of the
pipe (22) at this preferred location of contact.
The method is then comprised of the step of second moving the cutting head
(42) longitudinally relative to the pipe bed (38) along the longitudinal
clamping gap (52).
The second moving step is performed independently from the first moving step
and in
sequence following the first moving step. Accordingly, as a result of the
second moving
step, the perforated pipe wall (24) is further cut by the cutters (100)
through the longitudinal
clamping gap (52) to form a first plurality of discrete slots (30), each of
the slots (30)
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having a length. In the preferred embodiment, the second moving step moves the
cutting
head (42) substantially horizontally or in a horizontal plane.
A third moving step of the method moves the cutting head (42) away from
the longitudinal clamping gap (52) so that the cutters (100) are moved out of
engagement
with the pipe wall (24). In the preferred embodiment, the third moving step
again moves
the cutting head (42) substantially vertically or in a vertical plane to move
the cutters (100)
out of contact with the pipe wall (24). The clamping system (40) is then moved
to an
unclamped position from the clamped position.
Once in the unclamped position, the method is further comprised of the step
of rotating the pipe (22) about the pipe longitudinal axis. The previously
described steps of
the method are then repeated including moving the clamping system (40) to the
clamped
position, providing the movable cutting head (42) at the location adjacent the
pipe bed (38),
first moving the cutting head (42), second moving the cutting head (42) and
third moving
the cutting head (42) all in the manner described above. As a result of
repeating these steps,
a second plurality of discrete slots (30) are formed in the pipe wall (24),
wherein the first
plurality of discrete slots (30) and the second plurality of discrete slots
(30) are spaced
circumferentially about the pipe circumference. The method is further repeated
until the
desired number of rows of discrete slots (30) have been cut about the pipe
circumference.
The rows of the slots (30) may be cut side by side, staggered or in any other
pattern or
configuration desired by the operator performing the method.
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