Note: Descriptions are shown in the official language in which they were submitted.
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ADJUSTABLE SPRING LOADED VALVE
FOR A CORE BARREL HEAD ASSEMBLY
Field of the invention
The invention relates to aspects of a valve for an earth boring drilling
apparatus.
Background of the invention
In the course of exploratory drilling of the earth, rock samples are often
collected. The
samples may be collected from various depths of from hundreds to thousands of
meters.
Such samples are typically collected utilizing core barrel assemblies that
include double
core tubes having an inner core tube and an outer core tube. While the outer
tube may
extend through substantially the entire hole, the inner tube may be relatively
short, such as
on the order of a few meters.
In preparation for drilling, an inner tube is inserted into the outer tube
until it reaches the
bottom of the outer tube so that drilling can begin. A drilling fluid, such as
water, used to
flush drilling debris from the hole and the tubes may be utilized to exert a
force to advance
the inner tube through the outer tube. When the inner tube has reached the
correct
position, a latching mechanism immobilizes the inner tube with respect to the
outer tube.
However, since the inner tube is being advanced within the hole, it may be
difficult to
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determine with certainty that the inner tube has reached the proper position.
If the inner
tube has not actually reached the end of the hole, drilling may still begin.
In some cases, it
is just assumed that inner tube has reached the bottom of the outer tube when
it stops
moving. Another way to determine whether the inner tube has reached the
drilling
position has been to include a valve in the path of the drilling fluid. As the
drilling fluid is
introduced to apply pressure to insert the inner tube, the pressure of the
drilling fluid is
monitored. When the inner tube has moved to the end of the hole, the fluid
pressure will
increase to the point that the pressure opens the valve. This increased
pressure indicates
that the inner tube has reached the end of the hole.
As the sample is collected, the drilling fluid may also function to indicate
that the inner core
tube is full. Along these lines, as the tube fills, the pressure of the
drilling fluid increases.
When the pressure reaches a certain pressure, the tube is filled. The inner
tube and sample
may then be removed from the hole by attaching a retrieval mechanism to an end
of the
inner tube assembly. The retrieval mechanism engages an attachment mechanism
on the
inner tube. The retrieval mechanism then withdraws the inner tube and the
sample from
the outer tube.
Summary of the invention
Embodiments of the invention may include an adjustable spring loaded plunger
valve for a
core barrel head assembly for a drill string. The core barrel head assembly
includes a
latching mechanism. A valve rod is operatively connected to the latch
mechanism and
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extends toward a bit end of the drill string. An inward fluid flow port is
arranged between the
latching mechanism and the valve. An outward fluid flow port is arranged
toward the bit end
of the drill string. The valve includes a non-resilient valve ring and a
resilient valve ball. The
valve ball passes through the valve ring to open and close the valve. A
diameter of the
resilient ball valve is configured to be variable to vary a pressure required
to move the ball
valve through the valve ring.
Embodiments of the invention may also include a drilling apparatus head
assembly for a drill
string. A spear head is configured to engage a retrieving device for removing
the head assembly
from a hole. The spear head is arranged in a latch retracting case. A latching
mechanism is
moveable between a latched position and a retracted position. A valve rod is
operatively
connected to the latch mechanism and extends toward a bit end of the drill
string. A latch lock is
configured to maintain the latching mechanism in a latched position. A latch
spring is
configured to maintain the latching mechanism in an unlatched position. An
adjustable spring
loaded plunger valve includes a non-resilient valve ring and a resilient valve
ball. The valve ball
passes through the valve ring to open and close the valve. A diameter of the
resilient ball valve
is configured to be variable to vary a pressure required to move the ball
valve through the valve
ring. An inward fluid flow port is arranged between the latching mechanism and
the valve. An
outward fluid flow port arranged toward the bit end of the drill string.
Furthermore, embodiments of the invention may include a drilling apparatus
head assembly
for a drill string, comprising: a spear head configured to engage a retrieving
device for
removing the head assembly from a hole; a latch retracting case in which the
spear head is
arranged; a latching mechanism moveable between a latched position and a
retracted position;
a valve rod operatively connected to the latch mechanism and extending toward
a bit end of
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the drill string; a latch lock configured to maintain the latching mechanism
in a latched
position; a latch spring configured to maintain the latches in the retracted
position; a floating
connection configured to operatively connect the valve rod to the latching
mechanism, the
floating connection comprising a valve spring configured to counteract the
latch spring, a
spring seat adjustably attached to the valve rod, a roll pin arranged to
engage the valve spring
opposite the spring seat, the roll pin extending through a slot in a latch
body, such that the pin
slides in the slot as the spring expands and contracts, a lock nut configured
to adjust and limit
movement of the spring seat, or a flared, hollow end of the valve rod, the
floating connection
comprising a valve spring, a roll pin arranged to engage the valve spring, the
roll pin
extending through a slot in the flared, hollow portion of the valve rod, such
that the pin slides
in the slot, wherein the slot does not extend through the end of the valve
rod; an inward fluid
flow port arranged between the latching mechanism and the valve; and an
outward fluid flow
port arranged toward the bit end of the drill string.
Still other objects and advantages of the present invention will become
readily apparent by
those skilled in the art from the following detailed description, wherein it
is shown and
described only the preferred embodiments of the invention, simply by way of
illustration of
the best mode contemplated of carrying out the invention. As will be realized,
the invention is
capable of other and different embodiments, and its several details are
capable of
modifications in various obvious respects, without departing from the
invention.
Accordingly, the drawings and description are to be regarded as illustrative
in nature and not
as restrictive.
Brief description of the drawings
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The above-mentioned objects and advantages of the present invention will be
more clearly
understood when considered in conjunction with the accompanying drawings, in
which:
Fig. 1 represents a cross-sectional view of an embodiment of a drilling
apparatus head
assembly for a drill string;
Fig. la represents a close-up cross-sectional view of the portion la of the
embodiment
shown in Fig. 1;
Fig. 2 represents a cross-sectional view of another embodiment of a drilling
apparatus head
assembly for a drill string;
Fig. 2a represents a close-up cross-sectional view of the portion 2a of the
embodiment
shown in Fig. 2;
Fig. 2b represents a known alternative to the structure shown in Fig. 2a;
Fig. 3a represents a close-up view of an alternative embodiment of a valve
assembly; and
Fig. 3b represents a close-up view of a further alternative embodiment of a
valve assembly.
Detailed description of embodiments of the invention
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Fig. 1 illustrates and embodiment of a core barrel head assembly 1 according
to the
invention. The embodiment shown in Fig. 1 includes a latch retracting case 3.
The facilitate
retraction of the core barrel head assembly 1 from a hole, a retrieval
mechanism engaging
structure, such as a spear head 7, extends into the latch retracting case 3 in
the vicinity of a
top end 5 of the latch retracting case 3 such that a base 9 of the spear head
7 is arranged in
the latch retracting case 3. The latch retracting case 3 is arranged within
the outer tube
(not shown) of the core barrel assembly. The latch assembly also includes an
upper latch
body 19, a latch body coupler 21, and a lower latch body 23.
A latch mechanism 11 may include a pair of latches 13. The latches 13 are
shown in a
retracted position in Fig. 1. A latch lock 15 maintains the latches 13 in an
open, engaged
position, where the latches 13 engage the outer tube. A latch spring 17 pushes
the latch
mechanism 11 into an engaged and locked position. The latch spring 17 forces
the latch
lock 15 between the latches 13, to bias the latches 13 in the engaged
position. The latch
mechanism 11 may include a second spring 12 that also biases the latches 13 in
a closed
engaged position independent of the latch lock 15.
Fluid flows into the inner tube through inward fluid flow port 25. The inner
tube includes a
landing shoulder 27 that typically engages a shoulder or other structure on
the inner
surface of the outer tube when the inner tube is fully inserted into the outer
tube. Then,
when the valve mechanism 100 is opened, fluid can flow from the inward fluid
flow port
25, through the interior 29 of the inner tube, into the valve mechanism 100
and out from
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the lower latch body 23.
A valve rod 98 extends from the region of the latches 13 to the valve
mechanism 100. The
rod operatively connects the latch mechanism 11 to the valve mechanism 100.
According
to known designs, the valve rod 98 is connected to the latch retracting case
3. As such,
forces applied by the latch spring 17, through the spear head 7 or otherwise,
are typically
transmitted directly through the valve spring 92 to the valve rod 98 and to
the valve
mechanism 100.
Fig. 2a represents a close-up view of the portion 2a of the structure shown in
Fig. 2.
According to this embodiment, the valve rod 98a does not include a slot. As
such the roll
pin 90a does not extend through a slot in the valve rod 98a. Rather, a spring
seat 88a is
arranged about the valve rod 98a. The spring engages a surface of the spring
seat 88a. The
roll pin 90a engages the end of the valve spring 92a opposite the spring seat
88a. The
spring seat 88a may be limited in its movement by a lock nut 86a, which may be
secured in
place on the valve rod 98a. This may be accomplished by providing threads on
the valve
rod 98a and the spring seat 88a, by welding the spring seat 88a onto the valve
rod 98a,
through a screw extending through the spring seat 88a into the valve rod 98a
or any other
suitable attachment.
Since the embodiment shown in Fig. 2a does not include a slot in the valve rod
98a as in the
embodiment shown in Fig. 2b, an upward force applied to the latch mechanism
11, such as
when pulling the structure out of a hole through the spear head 7, will not
pull on the valve
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rod 98a. As can be seen in Fig. 2a, the valve rod 98a will float and is not
attached to the latch
mechanism 11. The floating connection will still provide a link between the
valve rod 98a and
the latch mechanism 11. However, since there is no fixed connection between
the latch
mechanism 11 and the valve rod 98a, removing the assembly by pulling on the
spear head 7
.. will not apply a pulling force on the valve ball 102. As a result, the
valve ball 102 will need to
be reset manually when the assembly is withdrawn from a hole. Additionally,
the floating
connection shown in Fig. 2a does not provide an indication that the latches 13
are engaged as
the assembly is advanced into a hole. A possible advantage of the embodiment
shown in
Fig. 2a is that it may be possible to add the floating connection to existing
drilling assemblies
without any modifications to the assemblies. The embodiment shown in Fig. 2a
may also have
better backflow when retrieving the inner tube assembly, leaving more water in
the hold when
the inner tube has reached the surface.
Fig. 2b represents another embodiment of the structure. In the structure shown
in Fig. 2b,
the end of the valve rod 98b adjacent the latch mechanism 11 is hollow and may
be flared as
shown in Fig. 2b. A spring 92b is arranged in the hollow portion of the valve
rod 98b.
Additionally, a slot 94b is provided in the wall of the hollow portion of the
valve rod 98b. A
roll pin 90b extends through the slot 94b. In this design, the spring can
counteract the force
that the latch spring 17 can apply to the valve rod 98b through the latch
mechanism 11. Since
the slot 94b at the top of the valve rod 98b does not extend through the end
of the valve rod
98b, an upward force applied on the valve rod 98b will move the valve ball 102
to close the
valve mechanism 100.
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In operation, the valve spring 92 counteracts the pressure of the latch spring
17. In fact, the
valve spring 92 may be stronger than the latch spring 17. As a result, the
valve spring 92
applies a greater force to the latch spring 17 than the latch spring 17
applies to the valve
spring 92. The force applied to the latch spring 17 by the valve spring 92
compresses the latch
spring 17 and as a result holds the latch retracting case 3 and latch lock 15
in a position so that
the latches 13 can move independently of the latch lock 15 from an engage
position to a
disengaged position. This may reduce the force of the latches 13 against the
inside wall of the
drilling string, reducing wear on the latches 13 and increasing the speed the
inner tube travels.
The latch mechanism 11 may also include a further spring to bias the latches
13 in an engaged
position and even when the latch lock 15 is in a disengaged position.
The valve spring 92 and latch spring 17 also apply pressure to the valve ball
102. However,
when the core barrel head assembly 1 lands on the landing ring 20a in Fig. 1
and landing ring
20b in Fig. 2, the valve spring 92 will absorb the impact so that the valve
ball 102 is not
pushed passed the valve ring 104 before the drill string is filled with fluid.
The core barrel head assembly 1 includes a valve mechanism 100. The valve
mechanism 100
includes a valve ball 102 and valve ring 104. The valve ball 102 is
operatively connected to
the end of the valve rod 98 opposite the latch mechanism 11. The valve ball
102 has a larger
diameter than the inner diameter of the valve ring 104.
The valve mechanism 100 functions similar to known valve mechanisms. Along
these lines,
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as the drilling fluid is introduced into the inner tube to advance the inner
tube into the
outer tube, when the tube comes to the bottom of the hole, fluid pressure will
build on the
valve ball 102. At some point, the pressure will exceed the pressure required
to force the
valve ball 102 through the valve ring 104. Then, the valve ball 102 will move
through the
valve ring 104 and permit fluid to pass through the outward fluid flow port
108. After the
valve ball 102 passes through the valve ring 104, the valve ball 102 will move
into a recess
110 located so that the valve ball 102 will be arranged below the outward
fluid flow port
108, thereby permitting free flow of fluid through the outward fluid flow port
108 with
reduced erosion by the fluid flow.
As drilling is carried out, fluid continues to flow through the system.
Accordingly, the fluid
continuously flows through the valve ring 104. As described above, the core
barrel head
assembly 1 includes a valve mechanism 100. Known assemblies employ a valve
mechanism that includes a resilient valve ring 104 and a rigid valve ball 102.
One problem
with such a configuration is that once the valve mechanism 100 opens and fluid
flows
through the valve mechanism 100, the resilient valve ring 104 is subject to
erosion by the
fluid flowing through the valve mechanism 100.
To address the problem of erosion of the valve ring 104, the invention
includes a valve ring
104 made of rigid material and a valve ball 102 made of resilient material. As
shown in
Figs 1 and la, the valve ball 102 is arranged substantially or entirely out of
the flow path of
the fluid flowing through the valve mechanism 100. By making the valve ring
104 and
valve ball 102 of resilient and rigid material, respectively, when the valve
mechanism 100
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opens, it is the valve ring 104 which the fluid flows past and the valve ball
102 is out of the
flow path of the fluid. Such an arrangement may greatly decrease wear on the
resilient portion
of the valve mechanism 100, in other words, the valve ball 102. Decreasing the
wear on the
parts of the mechanism 100 will increase the life span of the parts of the
valve mechanism 100
and decrease the need for replacement. This will decrease costs for valve
replacement as well
as by decreasing loss as a result of down time caused by the need to remove
the assembly
from service to replace the parts of the valve mechanism 100.
An additional advantage of making the valve ball 102 of a resilient material
and the valve ring
104 of rigid material is that the resilient valve ball 102 may permit the
valve mechanism 100
to be relatively easily adjusted, which is not possible with a resilient valve
ring 104. For
example, the diameter of the valve ball 102 may be adjusted. By adjusting the
diameter of the
valve ball 102, the pressure required to force the valve ball 102 through the
valve ring 104
may be adjusted.
The adjustable valve ball 102 permits the valve mechanism 100 to be adjusted
depending
upon the equipment and conditions in which the drilling is taking place. For
example, the
pressure required to open the valve mechanism 100 may be adjusted based upon
the depth of
the hole being drilled. In such a case, the valve ball 102 may be adjusted to
increase a pressure
required to open the valve mechanism 100.
The adjustable valve mechanism 100 can also permit the use of reduced drag
latches 13 in the
.. core barrel head assembly 1. Such latches 13 experience less wear than
typical latches.
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Additionally, the valve mechanism 100 can permit latches to engage
independently of the
position of the valve mechanism 100 when drag free latches are utilized.
The valve ring 104 according to the invention is typically made of metal.
Materials from
which the valve ring 104 may be formed include steel, hardened steel, ceramic,
and/or
ceramic coated resilient material, among others.
On the other hand, the valve ball 102 according to the invention is typically
made of plastic.
Materials from which the valve ball 102 may be formed include Nylon, Delrin,
UHMW, steel
or steel assembly, for example. In addition to being made of a resilient
material, the valve
ball 102 may be physically altered to increase its resiliency. For example,
the valve ball 102
may include grooves in its surface. Additionally or alternatively, material
may be removed
from the valve ball 102 to increase its resiliency. The material could be
removed from
anywhere in or on the valve ball 102.
Figs. 1 and la illustrate an embodiment of a valve assembly according to the
claimed
invention. The valve assembly includes a valve ring 104 made of rigid
material. The valve
ring 104 is arranged in an opening 105 in the lower latch body 23. The valve
ring 104 has
an outer diameter that is only slightly smaller than the diameter of the
opening 105 in
which the valve ring 104 is arranged, thereby making the valve ring 104 fit
snuggly in the
opening 105.
The inner wall 104a of the of the valve ring 104 has a minimum diameter that
is narrower
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than the outer diameter of the valve ball 102. In the embodiment shown in
Figs. 1 and la,
the inner wall 104a of the valve ring 104 is contoured such that the diameter
decreases
toward the middle of the valve ring 104 and only has the narrowest diameter in
the vicinity
of the center of the valve ring 104. This can facilitate the accurate
placement of the valve
ball 102 in the valve ring 104 as shown in Fig. la. The valve ring 104 may
include an
extended region 104b having the narrowest diameter as in the embodiment shown
in Figs.
3a and 3b.
As shown in Figs. 1 and la, the valve ball 102 is arranged at an end of the
valve rod 98,
which, as described above, is operatively connected to the latch assembly.
According to the
embodiment shown in Figs 1 and la, the valve ball 102 is operatively connected
to the
valve rod 98 with at least one valve adjusting element. For example, the
embodiment
shown in Fig. la includes a valve attaching screw 112. The valve adjusting
screw 112 may
extend through a passage in the valve ball 102.
As the valve attaching screw is advanced into the valve rod 98, the valve ball
102 will be
squeezed between the end 96 of the valve rod 98 and the valve adjusting screw
112. As the
valve ball 102 is squeezed, the diameter of the valve ball 102 will increase.
Once the valve
ball 102 diameter is larger than the inner diameter of the valve ring 104, any
increase in
diameter of the valve ball 102 will increase the level of force required to
move the valve
ball 102 through the valve ring 104.
Figs 3a and 3b illustrate alternative embodiments of a valve. As illustrated
in Figs. 3a and
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3b, the valve ball 102a and 102b may have a shape different from the valve
ball 102 shown
in both Figs. 3a and 3b, the valve ball 102a and 102b includes a ring of
material. The valve
ball 102a and 102b in these alternative embodiments may be made of the same
material as
the valve ball 102 described above. However, these alternative embodiments of
the valve
ball 102a and 102b are thinner than the valve ball 102 shown in Fig. la. As a
result, the
alternative embodiments of the valve ball 102a and 102b may be more easily
adjusted.
In Fig. 3a, the valve ball 102a is supported by a nut 114 applied onto the rod
106. On the
other hand, the embodiment shown in Fig. 3b includes a valve ball support 116.
The valve
ball support 116 may be made of the same material as the valve ball 102b.
Alternatively,
the valve ball support 116 may be made of a less resilient material than the
valve ball 102b.
To enhance the adjustability of the valve ball, the embodiments shown in Figs.
3a and 3b a
plurality of elements that provide a greater adjustability to the valve ball
102a and 102b.
For example, the embodiment shown in Fig. 3a includes valve ball adjustment
elements 36
and 43 and the embodiment shown in Fig. 3b includes valve ball adjustment
elements 37
and 42. In both cases, the valve ball adjustment elements 36 and 43 extend
from the valve
rod 98 a shorter distance than the valve ball 102a and 102b, thereby ensuring
that the
valve ball 102a and 102b engages the valve ring 104.
The valve adjustment elements 36 and 43 may include an internal threaded
connection and
the valve rod 98 an external threaded connection that permit the adjustment
elements to
be threaded onto the valve rod 98. By moving the valve adjustment elements
closer to each
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other or farther apart, the amount that the valve ball 102a is squeezed may be
adjusted.
The location of the valve ball adjustment elements 36 and 43 may be locked in
place on the
valve rod 98 by locking nut 34, which may also include an internal threaded
connection
that engages the external threaded connection 99 on the valve rod 98.
The valve ball 102a and valve ball adjustment elements 36 and 43 in the
embodiment
shown in Fig. 3a also include valve engagement surfaces and that are angled
with respect to
the longitudinal axis of the valve rod 98. The angled surfaces may make
smaller
refinements in the squeezing of the valve ball 102a possible. On the other
hand, the valve
ball 102b and valve ball adjustment elements 37 and 42 shown in Fig. 3b engage
the valve
ball 102b with surfaces that are parallel or perpendicular to the longitudinal
axis of the
valve rod 98. It is also possible to utilize a valve ball without angled
surfaces with valve
ball adjustment elements that include angled surfaces and vice versa.
The end 96 of the valve rod 98 may be flared as in the embodiment shown in
Figs. 1 and la.
This can help to ensure that tightening of the valve adjusting screw 112 will
increase the
diameter of the valve ball 102 and not permit the top surface 105 of the valve
ball 102 to be
forced upwardly. Similarly, the valve adjusting screw 112 may be flared.
Alternatively, a
washer 113 may be arranged between the valve adjusting screw 112 and the valve
ball
102. Either solution may help to ensure that tightening the valve adjusting
screw 112 in
the valve rod 98 will cause the valve ball 102 to increase in diameter rather
than result in
the valve adjusting screw 112 penetrating into the valve ball 102. In other
words, the valve
ball 102 will be compressed between the end of the valve rod 98 and the valve
adjusting
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screw 112.
Once the valve ball 102 is in the working position, the latch spring 17 will
be free to move
because the valve rod 98 will be moved with the valve ball 102. As such, the
latch spring 17
will be free to move the latch lock 15 between the latches 13 and lock the
latches 13 in an
engaged position. If the latches 13 are jammed and cannot fully engage, the
floating
connection between the valve rod 98 and the latch assembly will prevent the
valve from
moving to the working position. In such a case, the fluid pressure will remain
high, thereby
indicating that there is a mis-latch.
When the inner tube is filled with material and the core barrel head assembly
1 is ready to
be removed, a retrieving mechanism, such as an overshot, will be attached to
the spear
head 7. After the retrieving mechanism is attached to the core barrel head
assembly 1, the
retrieving mechanism applies a pulling force to the latch retracting case 3.
This force will
compress the latch spring 17, moving the latch lock 15 to a position to permit
the latch
retracting case 3 to retract the latches 13.
As the latches 13 retract, the valve rod 98 will withdraw the valve ball 102
up through the
valve ring 104. The valve ball 102 may be moved above the valve ring 104 to
permit fluid
to continue to flow through the valve ring 104. However, if the valve rod 98
includes a
floating connection as described above, the valve ball 102 will not be
withdrawn through
the valve ring 104.
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The foregoing description of the invention illustrates and describes
embodiments of the
invention. Additionally, the disclosure shows and describes only the
embodiments of the
invention, but as aforementioned, it is to be understood that the invention is
capable of use
in various other combinations, modifications, and environments and is capable
of changes
or modifications within the scope of the inventive concept as expressed
herein,
commensurate with the above teachings, and/or the skill or knowledge of the
relevant art.
The embodiments described hereinabove are further intended to explain best
modes
known of practicing the invention and to enable others skilled in the art to
utilize the
invention in such, or other, embodiments and with the various modifications
required by
the particular applications or uses of the invention. Accordingly, the
description is not
intended to limit the invention to the form disclosed herein. Also, it is
intended that the
appended claims be construed to include alternative embodiments.
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