U.S. patent application number 14/842895 was filed with the patent office on 2017-03-02 for blowout preventer with pipe ram packer assemblies with support tab.
This patent application is currently assigned to CAMERON INTERNATIONAL CORPORATION. The applicant listed for this patent is Cameron International Corporation. Invention is credited to Raul Araujo, Jeff Lambert.
Application Number | 20170058625 14/842895 |
Document ID | / |
Family ID | 58103559 |
Filed Date | 2017-03-02 |
United States Patent
Application |
20170058625 |
Kind Code |
A1 |
Araujo; Raul ; et
al. |
March 2, 2017 |
Blowout Preventer with Pipe Ram Packer Assemblies with Support
Tab
Abstract
A pipe ram blowout preventer may be used for sealing about an
object positioned in a vertical bore extending through the blowout
preventer. The blowout preventer includes a pipe ram assembly
movable towards the tubular, the pipe ram assembly including a
packer assembly comprising an elastomeric body for sealing against
the object. The packer assembly includes an upper plate position
above the elastomeric body which includes a tab extending from the
upper plate. The tab resists extrusion of the elastomeric body in
high temperature environments by containing the elastomeric
material and forming a metal-to-metal seal about the object
positioned in the blowout preventer vertical bore.
Inventors: |
Araujo; Raul; (Cypress,
TX) ; Lambert; Jeff; (Tomball, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cameron International Corporation |
Houston |
TX |
US |
|
|
Assignee: |
CAMERON INTERNATIONAL
CORPORATION
Houston
TX
|
Family ID: |
58103559 |
Appl. No.: |
14/842895 |
Filed: |
September 2, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 33/062
20130101 |
International
Class: |
E21B 33/06 20060101
E21B033/06 |
Claims
1. A blowout preventer ("BOP") assembly for sealing against an
object, comprising: a body comprising a vertical bore extending
through the body; pipe ram assemblies configured to seal about the
object when located in the vertical bore, each pipe ram assembly
comprising a packer assembly comprising: an upper plate; a lower
plate; a body positioned between the upper and lower plates, the
body comprising an elastomeric material and a surface configured to
engage the object; and a tab extending from one of the upper and
lower plates, wherein the tab is configured to diminish extrusion
of the elastomeric material.
2. The BOP assembly of claim 1, where the tab is configured to
diminish extrusion of the elastomeric material during sealing
operations at temperatures at or above about 350.degree. F.
3. The BOP assembly of claim 1, wherein the body is semi-elliptical
in shape.
4. The BOP assembly of claim 1, wherein the body is elliptical in
shape.
5. The BOP assembly of claim 1, further comprising: the upper plate
further comprising a height H.sub.P; and the tab comprising a
height H.sub.T, wherein H.sub.T is greater than H.sub.P.
6. The BOP assembly of claim 1, wherein the upper plate and tab
comprise different materials of construction.
7. The BOP assembly of claim 1, wherein the tab is further
configured to form a metal-to-metal seal with the object.
8. The BOP assembly of claim 1, wherein the elastomeric material
comprises at least one of synthetic and natural rubber
9. The BOP assembly of claim 1, wherein the object is one of a
drill pipe joint, casing joint, or tool joint.
10. The BOP assembly of claim 1, wherein the packer assemblies are
each coupled to the ram assemblies via one or more fasteners.
11. A packer assembly for a pipe ram blowout preventer configured
to seal about an object located in a vertical bore of the blowout
preventer, the packer assembly comprising: an upper plate; a lower
plate; a body positioned between the upper and lower plates, the
body comprising an elastomeric material and a surface configured to
engage the object; and a tab extending from one of the upper and
lower plates, wherein the tab is configured to diminish extrusion
of the elastomeric material.
12. The packer assembly of claim 11, wherein the tab extends from
the upper plate.
13. The packer assembly of claim 11, wherein the tab is configured
to diminish extrusion of the elastomeric material during sealing
operations at temperatures at or above about 350.degree. F.
14. The packer assembly of claim 11, wherein the body is
semi-elliptical in shape.
15. The packer assembly of claim 11, wherein the body is elliptical
in shape.
16. The packer assembly of claim 11, further comprising: the upper
plate further comprising a height H.sub.P; and the tab comprising a
height H.sub.T, wherein H.sub.T is greater than H.sub.P.
17. The packer assembly of claim 11, wherein the upper plate and
tab comprise different materials of construction.
18. The packer assembly of claim 11, wherein the tab is further
configured to form a metal-to-metal seal with the object.
19. The packer assembly of claim 11, wherein the elastomeric
material comprises at least one of synthetic and natural rubber
20. The packer assembly of claim 11, wherein the object is one of a
drill pipe joint, casing joint, or tool joint.
Description
BACKGROUND
[0001] This section is intended to introduce the reader to various
aspects of art that may be related to various aspects of the
presently described embodiments. This discussion is believed to be
helpful in providing the reader with background information to
facilitate a better understanding of the various aspects of the
present embodiments. Accordingly, it should be understood that
these statements are to be read in this light, and not as
admissions of prior art.
[0002] Blowout preventers are used extensively throughout the oil
and gas industry. Typical blowout preventers are used as a large
specialized valve or similar mechanical device that seal, control,
and monitor oil and gas wells. The two categories of blowout
preventers that are most prevalent are ram blowout preventers and
annular blowout preventers. Blowout preventer stacks frequently
utilize both types, typically with at least one annular blowout
preventer stacked above several ram blowout preventers. The ram
units in ram blowout preventers allow for shearing drill pipe in
the case of shear rams, and sealing off around drill pipe in the
case of pipe rams. Typically, a blowout preventer stack may be
secured to a wellhead and may provide a safe means for sealing the
well in the event of a system failure.
[0003] A typical blowout preventer includes a main body or housing
with a vertical bore. Ram bonnet assemblies may be bolted to
opposing sides of the main body using a number of high tensile
fasteners, such as bolts or studs. These fasteners are required to
hold the bonnet in position to enable the sealing arrangements to
work effectively. Typically an elastomeric sealing element is used
between the ram bonnet and the main body. There are several
configurations, but essentially they are all directed to preventing
a leakage bypass between the mating faces of the ram bonnet and the
main body. Each bonnet assembly includes a piston which is
laterally movable within a ram cavity of the bonnet assembly by
pressurized hydraulic fluid acting on one side of the piston. The
opposite side of each piston has a connecting rod attached thereto
which in turn has a ram mounted thereon. The rams can be shear rams
for shearing an object within the bore of a blowout preventer.
Alternatively, the rams can be pipe rams for sealing off around an
object within the bore of a blowout preventer, thereby sealing the
annular space between the object and the blowout preventer
bore.
[0004] These rams are designed to move laterally toward the
vertical bore of the blowout preventer to shear or seal off on any
object located therein. For instance, opposing pipe rams utilize
seals that close in on and seal off on a tubular within the
vertical bore of the blowout preventer, such as a section of drill
pipe used during drilling operations. Each pipe ram typically has a
semicircular opening in its front face to form a seal about half of
the outer periphery of the object within the blowout preventer
vertical bore. When the opposing pipe rams are closed, the opposing
pipe rams engage each other and seal the entire periphery of the
object, thereby closing off the annulus between the object and the
blowout preventer bore.
[0005] Typical pipe ram assemblies can include a ram packer
assembly including a packer body which is composed of an
elastomeric or rubber material and is configured to seal off
against the tubular within the vertical bore of the blowout
preventer when the opposing rams are run into the closed position.
The elastomeric or rubber material of the ram packer assembly body
is positioned between upper and lower plates. The plates provide
structure for the ram packer and facilitate insertion of the ram
packer into a pipe ram assembly.
[0006] Ram packers are susceptible to mechanical wear, particularly
at high temperature. For instance, at high temperatures, such as
over 350.degree. F., the elastomeric or rubber material of a ram
packer can flow and extrude past the upper plate of the ram packer
into the blowout preventer borehole. When this occurs, the sealing
capability of the ram packer declines.
[0007] Accordingly, a pipe ram packer assembly that is suitable for
sealing off on an object in a bore of a blowout preventer is
desirable, particularly at high temperature. More particularly, a
pipe ram packer assembly including an upper and/or lower plate that
resists extrusion of the packer elastomeric body is desirable.
DESCRIPTION OF THE DRAWINGS
[0008] For a detailed description of the preferred embodiments of
the present disclosure, reference will now be made to the
accompanying drawings in which:
[0009] FIG. 1 shows a sectional view of a pipe ram blowout
preventer in accordance with one or more embodiments;
[0010] FIG. 2 shows a perspective view of a ram assembly including
a packer assembly in accordance with one or more embodiments;
[0011] FIG. 3 shows a perspective view of a packer assembly
including an elastomeric body located therein in accordance with
one or more embodiments;
[0012] FIG. 4 shows a perspective view of an upper plate of a
packer assembly, the upper plate including a tab extending
therefrom in accordance with one or more embodiments;
[0013] FIG. 5 shows a partial cross-sectional view of a tab
extending from an upper plate of a packer assembly in accordance
with one or more embodiments; and
[0014] FIG. 6 shows a partial cross-sectional view of a tab
extending from an upper plate of a packer assembly in accordance
with one or more embodiments.
DETAILED DESCRIPTION
[0015] The following discussion is directed to various embodiments
of the present disclosure. The drawing figures are not necessarily
to scale. Certain features of the embodiments may be shown
exaggerated in scale or in somewhat schematic form and some details
of conventional elements may not be shown in the interest of
clarity and conciseness. Although one or more of these embodiments
may be preferred, the embodiments disclosed should not be
interpreted, or otherwise used, as limiting the scope of the
disclosure, including the claims. It is to be fully recognized that
the different teachings of the embodiments discussed below may be
employed separately or in any suitable combination to produce
desired results. In addition, one skilled in the art will
understand that the following description has broad application,
and the discussion of any embodiment is meant only to be exemplary
of that embodiment, and not intended to intimate that the scope of
the disclosure, including the claims, is limited to that
embodiment.
[0016] Certain terms are used throughout the following description
and claims to refer to particular features or components. As one
skilled in the art will appreciate, different persons may refer to
the same feature or component by different names. This document
does not intend to distinguish between components or features that
differ in name but are the same structure or function. The drawing
figures are not necessarily to scale. Certain features and
components herein may be shown exaggerated in scale or in somewhat
schematic form and some details of conventional elements may not be
shown in interest of clarity and conciseness.
[0017] In the following discussion and in the claims, the terms
"including" and "comprising" are used in an open-ended fashion, and
thus should be interpreted to mean "including, but not limited to .
. . ." Also, the term "couple" or "couples" is intended to mean
either an indirect or direct connection. In addition, the terms
"axial" and "axially" generally mean along or parallel to a central
axis (e.g., central axis of a body or a port), while the terms
"radial" and "radially" generally mean perpendicular to the central
axis. For instance, an axial distance refers to a distance measured
along or parallel to the central axis, and a radial distance means
a distance measured perpendicular to the central axis. The use of
"top," "bottom," "above," "below," and variations of these terms is
made for convenience, but does not require any particular
orientation of the components.
[0018] Reference throughout this specification to "one embodiment,"
"an embodiment," or similar language means that a particular
feature, structure, or characteristic described in connection with
the embodiment may be included in at least one embodiment of the
present disclosure. Thus, appearances of the phrases "in one
embodiment," "in an embodiment," and similar language throughout
this specification may, but do not necessarily, all refer to the
same embodiment.
[0019] Referring now to FIG. 1, a sectional view of a pipe ram
blowout preventer 10 in accordance with one or more embodiments is
shown. The blowout preventer 10 includes a housing 12, such as a
hollow body, with a vertical bore 14 that enables passage of fluid
or an object, such as a tubular member, through the blowout
preventer 10. The housing 12 further includes one or more cavities,
such as ram cavities 16 opposed from each other with respect to the
vertical bore 14, with a pipe ram assembly 18 movably positioned
within each cavity 16. The blowout preventer 10 may be coupled to
other equipment that facilitates natural resource production. For
instance, production equipment or other components may be attached
to the top of the blowout preventer 10 using a connection 20 (which
may be facilitated in the form of fasteners), and the blowout
preventer 10 may be attached to a wellhead or spool using the
flange 22 and additional fasteners.
[0020] One or more bonnet assemblies 24 are secured to the housing
12 and include various components that facilitate control of the
ram assemblies 18 positioned in the blowout preventer 10. The
bonnet assemblies 24 are coupled to the housing 12 by using one or
more fasteners 26 to secure the bonnets 28 of the bonnet assemblies
24 to the housing 12. The ram assemblies 18 are then actuated and
moved through the cavities 16, into and out of the bore 14, by
operating and moving a piston 30 and a rod 32 coupled thereto
within a housing 34 of the bonnet assemblies 24.
[0021] In operation, a force (e.g., from hydraulic pressure) may be
applied to the pistons 30 to drive the rods 32, which in turn
drives the rams 18 coupled thereto into the bore 14 of the blowout
preventer 10. The ram assemblies 18 cooperate with one another when
driven together to seal the bore 14 and inhibit flow through the
blowout preventer 10.
[0022] In this embodiment, a hydraulic actuator is shown, though
any type of actuator (e.g., pneumatic, electrical, mechanical) may
be used in accordance with the present disclosure. As such, this
embodiment may include a piston 30 and a rod 32 connecting the
piston 30 to ram assembly 18. Further, pressurized fluid may be
introduced and fluidly communicated on opposite sides of the piston
30 thereby enabling the piston 30 to move the ram assembly 18 in
response to fluid pressure.
[0023] Turning now to FIG. 2, a ram assembly 200 including a packer
assembly 202 in accordance with one or more embodiments is shown.
Ram assembly 200 is similar to ram assembly 18 illustrated in FIG.
1. Ram assembly 200 includes a ram body 204, top seal 206, and
packer assembly 202. Ram body 204 has generally rounded sides 208
that fit in laterally disposed ram cavities of a blowout preventer,
such as ram cavities 16 illustrated in FIG. 1.
[0024] Ram body 204 includes an upper body 210 and a lower body 212
connected by front face 214 and defining a packer assembly cavity
therebetween. In the illustrated embodiment, packer assembly 202 is
inserted within the packer assembly cavity. Formed within front
face 214 of upper body 210 is ram bore profile 216. Ram bore
profile 216 is substantially semi-circularly shaped and extends
vertically through upper body 210 and lower body 212 to packer
assembly 202.
[0025] Turning now to FIG. 3, a packer assembly 300 in accordance
with one or more embodiments is shown. Packer assembly 300 is
similar to packer assembly 202 illustrated in FIG. 2. Packer
assembly 300 includes an upper plate 302 and a lower plate 304.
Upper plate 302 includes a tab 312 extending downwardly from upper
plate 302. Tab 312 is configured to resist extrusion of packer
assembly body 306 into the blowout preventer bore and to form a
metal-to-metal seal with the object in the bore. Packer assembly
body 306 is molded in a semi-elliptical shape and positioned
between upper plate 302 and lower plate 304. Body 306 can be molded
in any desired shape, such as semi-elliptical, elliptical,
circular, etc.
[0026] Body 306 is fastened to upper plate 302 via fasteners 308,
such as screws or bolts. Body 306 is likewise coupled to lower
plate 304 via fasteners, which are not shown in this illustration.
In the illustrated embodiment, four fasteners 308 are shown.
However, any number of fasteners may be used to secure body 306 to
upper plate 302 and lower plate 304. A packer bore profile 310 is
formed through upper plate 302, lower plate 304, and body 306. Body
306 is configured to be coupled to a ram assembly, such as ram
assembly 200 illustrated in FIG. 2, by way of fasteners 314. One
fastener 314 is positioned on each side of body 306 and configured
to couple body 306 to a ram assembly. However, any number of
fasteners 314 may be used.
[0027] Packer assembly body 306 is constructed of an elastomeric
material, such as any synthetic or natural rubber, or combination
thereof. Body 306 is configured to seal about an object located
within a vertical bore of a blowout preventer when packer assembly
300 is moved to a closed position. In particular, body 306 is
configured to seal about 180.degree. of the object to be sealed
upon. A corresponding packer assembly body in a corresponding
packer assembly closes on the object from the opposing side and
seals about the other 180.degree. of the object. Exemplary objects
to be sealed upon include a drill pipe joint, a casing joint, and a
tool joint. In this way, packer assembly 300, together with a
corresponding and opposing packer assembly run from an opposing
side, provides for a fluid seal in the annular region between an
object in a blowout preventer borehole and the blowout preventer
housing. Packer assembly body 306 may include one or more inserts
within body 306 to enhance the sealing ability of elastomer
306.
[0028] Turning now to FIG. 4, packer assembly 400 in accordance
with one or more embodiments is shown, with the elastomer and
fasteners removed, thereby revealing upper plate 402 and tab 404.
Tab 404 is shown extending downwardly from upper plate 402. In the
illustrated embodiment, tab 404 is shown extending from upper plate
402 in the bore profile 406 of packer assembly 400. That is, tab
404 does not extend along the generally straight edges 408 of upper
plate 402, but is only located along the semi-circular portion 410
of upper plate 402. However, in other embodiments tab 404 can
extend from upper plate 402 along the generally straight edges 408
of upper plate 402 only, or in addition to extending from the
semi-circular portion 410 of upper plate 402. In addition, tab 404
can be integral with upper plate 402, i.e., upper plate 402 and tab
404 are constructed from a single piece of material. In alternative
embodiments, tab 404 can be constructed of a different material
than upper plate 402.
[0029] Tab 402 is configured to resist packer assembly body
elastomer flow and extrusion, particularly at high temperatures,
such as temperatures above about 350.degree. F. (approximately
177.degree. C.), particularly at temperatures above about
400.degree. F. (approximately 205.degree. C.). As discussed above,
it is common for elastomeric packer bodies to flow and extrude into
the blowout preventer bore at such high temperatures. When the
elastomeric material flows into the blowout preventer bore, the
sealing efficiency of the packer assembly diminishes. Tab 402
essentially functions as a barrier for the elastomeric body,
preventing the elastomer material from flowing into the blowout
preventer bore when the elastomer material flows. Tab 402 contains
the elastomer material while still allowing the packer assembly to
seal about an object in a blowout preventer bore during closing
operations. In addition, tab 402 is configured to form a
metal-to-metal seal with the object positioned within the blowout
preventer bore when packer assembly 400, together with an
associated ram assembly, is closed on an object in a blowout
preventer bore during closing operations.
[0030] Tab 402 can be incorporated into the packer assemblies of
newly manufactured ram assemblies. Alternatively, tab 402 can be
retrofitted to an existing ram assembly. In this way, older pipe
ram assemblies can be retrofitted to extend the life of the ram
assemblies and enable existing assemblies for use in higher
temperature environments.
[0031] Turning now to FIG. 5, a partial cross-sectional view of ram
assembly 500 in accordance with one or more embodiments is shown.
Ram assembly 500 is similar to ram assembly 200 illustrated in FIG.
2. Ram assembly 500 includes an upper plate 502, which comprises a
tab 504, and a packer body 506. Packer body 506 comprises an
elastomer material configured to seal about the wall of an object
508 positioned in a blowout preventer bore. As illustrated, ram
assembly 500 is run in to a closed position, i.e., is in a position
in which tab 504 and body 506 are in contact with object 508. Tab
504 forms a metal-to-metal seal with the wall of object 508,
thereby preventing fluid flow vertically across an annular region
formed between object 508 and the blowout preventer bore. Likewise,
body 506 forms a seal with object 508, also restricting flow. As
discussed above, tab 504 will prevent extrusion of body 506 into
the bore of the blowout preventer, thereby preserving the sealing
capability of body 506. The lower portion of tab 504 extends
laterally toward the object 508 as a result of elastomer 506
pushing against tab 504. Tab 504 can return to its original
position (i.e., parallel to the bore of the blowout preventer) when
it seals against object 508.
[0032] Upper plate 502 includes a height H.sub.P and tab 504
includes a height H.sub.T. Tab 504 extends downwardly from upper
plate 502 and height H.sub.T is greater than height H.sub.P. The
difference between heights H.sub.T and H.sub.P is the length of the
tab 504 extension beyond the bottom surface of upper plate 502.
Heights H.sub.T and H.sub.P and the length of the extension beyond
the bottom surface of upper plate 502 can be optimized depending on
the size of packer assembly 500, the size of object 508 to be
sealed upon, or any other design considerations.
[0033] Turning now to FIG. 6, a partial cross-sectional view of ram
assembly 600 in accordance with one or more embodiments is shown.
Ram assembly 500 is similar to ram assembly 200 illustrated in FIG.
2. Ram assembly 600 includes an upper plate 602, which comprises a
tab 604, and a packer body 606. Packer body 606 comprises an
elastomer material configured to seal about the wall of an object
608 positioned in a blowout preventer bore. As illustrated, ram
assembly 600 is run in to a closed position, i.e., is in a position
in which tab 604 and body 606 are in contact with object 608. Tab
604 forms a metal-to-metal seal with the wall of object 608,
thereby preventing fluid flow vertically across an annular region
formed between object 608 and the blowout preventer bore. Likewise,
body 606 forms a seal with object 608, also restricting flow. As
discussed above, tab 604 will prevent extrusion of body 606 into
the bore of the blowout preventer, thereby preserving the sealing
capability of body 606.
[0034] In addition to the embodiments described above, many
examples of specific combinations are within the scope of the
disclosure, some of which are detailed below:
Example 1
[0035] A packer assembly for a pipe ram blowout preventer
configured to seal about an object located in a vertical bore of
the blowout preventer, the packer assembly comprising: [0036] an
upper plate; [0037] a lower plate; [0038] a body positioned between
the upper and lower plates, the body comprising an elastomeric
material and a surface configured to engage the object; and [0039]
a tab extending from one of the upper and lower plates, wherein the
tab is configured to diminish extrusion of the elastomeric
material.
Example 2
[0040] The packer assembly of Example 1, wherein the tab extends
from the upper plate.
Example 3
[0041] The packer assembly of Example 1, wherein the tab is
configured to diminish extrusion of the elastomeric material during
sealing operations at temperatures at or above about 350.degree.
F.
Example 4
[0042] The packer assembly of Example 1, wherein the body is
semi-elliptical in shape.
Example 5
[0043] The packer assembly of Example 1, wherein the body is
elliptical in shape.
Example 6
[0044] The packer assembly of Example 1, further comprising: [0045]
the upper plate further comprising a height H.sub.P; and [0046] the
tab comprising a height H.sub.T, wherein H.sub.T is greater than
H.sub.P.
Example 7
[0047] The packer assembly of Example 1, wherein the upper plate
and tab comprise different materials of construction.
Example 8
[0048] The packer assembly of Example 1, wherein the tab is further
configured to form a metal-to-metal seal with the object.
Example 9
[0049] The packer assembly of Example 1, wherein the elastomeric
material is synthetic or natural rubber
Example 10
[0050] The packer assembly of Example 1, wherein the object is one
of a drill pipe joint, casing joint, or tool joint.
Example 11
[0051] A blowout preventer ("BOP") assembly comprising: [0052] a
body comprising a vertical bore extending through the body and a
ram cavity intersecting the bore; [0053] a hydraulically actuated
pipe ram configured to seal about an object located in the vertical
bore, the pipe ram comprising a packer assembly comprising: [0054]
a an upper plate; [0055] a lower plate; [0056] a body positioned
between the upper and lower plates, the body comprising an
elastomeric material and a surface configured to engage the object;
and [0057] a tab extending from one of the upper and lower plates,
wherein the tab is configured to diminish extrusion of the
elastomeric material.
Example 12
[0058] The BOP assembly of Example 11, where the tab is configured
to diminish extrusion of the elastomeric material during sealing
operations at temperatures at or above about 350.degree. F.
Example 13
[0059] The BOP assembly of Example 11, wherein the body is
semi-elliptical in shape.
Example 14
[0060] The BOP assembly of Example 11, wherein the body is
elliptical in shape.
Example 15
[0061] The BOP assembly of Example 11, further comprising: [0062]
the upper plate further comprising a height H.sub.P; and [0063] the
tab comprising a height H.sub.T, wherein H.sub.T is greater than
H.sub.P.
Example 16
[0064] The BOP assembly of Example 11, wherein the upper plate and
tab comprise different materials of construction.
Example 17
[0065] The BOP assembly of Example 11, wherein the tab is further
configured to form a metal-to-metal seal with the object.
Example 18
[0066] The BOP assembly of Example 11, wherein the elastomeric
material is synthetic or natural rubber
Example 19
[0067] The BOP assembly of Example 11, wherein the object is one of
a drill pipe joint, casing joint, or tool joint.
Example 20
[0068] The BOP assembly of Example 11, further comprising another
an opposing hydraulically actuated pipe ram configured to seal
about the object located in the vertical bore, the opposing pipe
ram comprising a packer assembly comprising an tab extending from
an upper plate.
[0069] While the aspects of the present disclosure may be
susceptible to various modifications and alternative forms,
specific embodiments have been shown by way of example in the
drawings and have been described in detail herein. But it should be
understood that the invention is not intended to be limited to the
particular forms disclosed. Rather, the invention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the following
appended claims.
* * * * *