Note: Descriptions are shown in the official language in which they were submitted.
Rotatable and Wet-Mateable Connector
Cross-Reference to Related Applications
[0001] N/A
Background of the Disclosure
[0002] In the oil and gas industry, downhole measurement and logging tools
are generally
connected in series to form an interconnected suite of tools used while
drilling. Electrical power
and data are commonly passed from one tool to another. Such tools are
typically mounted to and
housed within the interior regions of drill collars. At the wellsite the drill
collars are themselves
joined end-to-end (typically using "box and pin" threaded connectors) to form
a bottomhole
assembly to convey the various tools into the wellbore.
[0003] It has proved useful to have electrical connectors that are both
rotatable and wet-
mateable. Existing rotatable, wet-mateable electrical connectors in the oil
and gas industry
generally fall into one of two main categories. One such category uses
elastomeric molded male
and/or female connectors with no moving or replaceable parts. See, for
example, U.S. Patent No.
4,500,156 issued to Nguyen. In that invention, the male connector acts as
plunger, expelling any
fluid present in the female cavity through a weep hole at or near one end of a
cavity. The
surrounding elastomer provides the necessary sealing and electrical
insolation. This design allows
for compact design, but is generally non-serviceable at the wellsite. The
number of life cycles is
limited due to contaminant buildup at the female contact(s), and abrasion on
the elastomer during
insertion can cause fluid leakage and, hence, electrical shorts between
contacts should there be
more than one. The number of electrical contacts is typically only one or two.
[0004] The other main category uses a female connector in conjunction with
a dry mating
chamber, properly sealed to prevent fluid invasion. Generally, the female
connector comprises
individual contacts with isolating elements and a spring-loaded retractable
plunger guarding the
mating chamber. This design allows for minimal abrasion on the contacts during
insertion. It also
provides good electrical isolation between contacts. However, it is typically
expensive and leads
to excessive tool length. Maintenance is difficult, in part because of a large
number of moving
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Date Recue/Date Received 2021-10-05
parts, but also because it must be performed in a clean, controlled
environment. Contaminant
buildup inside the female cavity requires more frequent service intervals.
[0005] Conventional electric connectors rely on metal-to-metal interaction
at discrete points
or lines secured by springs or some form of mechanical interference. These
contacts are either
non-serviceable or very difficult to replace. Because of their mechanical
nature, they tend to wear
out and/or the mating surfaces are damaged quite easily.
Summary
[0006] A mating connector that is rotatable and wet-mateable is disclosed
herein. The
connector has mating components that can be characterized as male and female.
The connector
may have one or more electrical and/or non-electrical contacts. As used
herein, "wet-mateable"
or "wet-connectable" means proper mating of the male and female components can
be achieved
even in the presence of conductive fluid. Being rotatable means the male and
female components
can be rotated independently during the mating process. A male component of a
rotatable and
wet-mateable mating connector is provided that has conductive and non-
conductive sealing
elements. A female component of the rotatable and wet-mateable mating
connector is provided
having conductive elements that are complementary to the male component. The
male component
is inserted into a chamber within the female component to produce the
rotatable and wet-mateable
mating connector.
[0007] This summary is provided to introduce a selection of concepts that
are further described
below in the detailed description. This summary is not intended to identify
key or essential features
of the claimed subject matter, nor is it intended to be used as an aid in
limiting the scope of the
claimed subject matter.
Brief Description of the Drawings
[0008] The present disclosure is best understood from the following
detailed description when
read with the accompanying figures. It is emphasized that, in accordance with
the standard practice
in the industry, various features are not drawn to scale. In fact, the
dimensions of the various
features may be arbitrarily increased or reduced for clarity of discussion.
Embodiments are
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Date Recue/Date Received 2021-10-05
described with reference to the following figures. The same numbers are
generally used
throughout the figures to reference like features and components.
[0009] Figure 1 is cross-sectional schematic drawing of one embodiment of a
male component
of a mating connector, in accordance with the present disclosure.
[0010] Figure 2 is cross-sectional schematic drawing of one embodiment of a
female
component of the mating connector of Figure 1, in accordance with the present
disclosure.
[0011] Figure 3 is cross-sectional schematic drawing of one embodiment of
the male
component of Figure 1 and the female component of Figure 2 in their connected
configuration, in
accordance with the present disclosure.
[0012] Figure 4 is a schematic view of one embodiment of a male connector
assembly shown
with a portion of a sleeve removed to expose its interior, in accordance with
the present disclosure.
[0013] Figure 5 is a schematic view of one embodiment of a female connector
assembly, in
accordance with the present disclosure.
[0014] Figure 6 is a schematic view of one embodiment of the male connector
assembly of
Figure 4 and the female connector assembly of Figure 5 as an upper drill
collar approaches a lower
drill collar, just prior to being joined, in accordance with the present
disclosure.
[0015] Figure 7 is a flowchart to produce a rotatable and wet-mateable
mating connector, in
accordance with the present disclosure.
Detailed Description
[0016] It is to be understood that the following disclosure provides many
different
embodiments, or examples, for implementing different features of various
embodiments. Specific
examples of components and arrangements are described below to simplify the
present disclosure.
These are, of course, merely examples and are not intended to be limiting. In
addition, the present
disclosure may repeat reference numerals and/or letters in the various
examples. This repetition
is for the purpose of simplicity and clarity and does not in itself dictate a
relationship between the
various embodiments and/or configurations discussed. Moreover, the formation
of a first feature
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Date Recue/Date Received 2021-10-05
over or on a second feature in the description that follows may include
embodiments in which the
first and second features are formed in direct contact, and may also include
embodiments in which
additional features may be formed interposing the first and second features,
such that the first and
second features may not be in direct contact.
[0017] Some embodiments will now be described with reference to the
figures. Like elements
in the various figures may be referenced with like numbers for consistency. In
the following
description, numerous details are set forth to provide an understanding of
various embodiments
and/or features. However, it will be understood by those skilled in the art
that some embodiments
may be practiced without many of these details and that numerous variations or
modifications from
the described embodiments are possible. As used here, the terms "above" and
"below", "up" and
"down", "upper" and "lower", "upwardly" and "downwardly", and other like terms
indicating
relative positions above or below a given point or element are used in this
description to more
clearly describe certain embodiments. However, when applied to equipment and
methods for use
in wells that are deviated or horizontal, such terms may refer to a left to
right, right to left, or
diagonal relationship, as appropriate. It will also be understood that,
although the terms first,
second, etc. may be used herein to describe various elements, these elements
should not be limited
by these terms. These terms are only used to distinguish one element from
another.
[0018] The terminology used in the description herein is for the purpose of
describing
particular embodiments only and is not intended to be limiting. As used in the
description and the
appended claims, the singular forms "a", "an" and "the" are intended to
include the plural forms
as well, unless the context clearly indicates otherwise. It will also be
understood that the term
"and/or" as used herein refers to and encompasses any and all possible
combinations of one or
more of the associated listed items. It will be further understood that the
terms "includes,"
"including," "comprises," and/or "comprising," when used in this
specification, specify the
presence of stated features, steps, operations, elements, and/or components,
but do not preclude
the presence or addition of one or more other features, steps, operations,
elements, components,
and/or groups thereof.
[0019] As used herein, the term "if' may be construed to mean "when" or
"upon" or "in
response to determining" or "in response to detecting," depending on the
context. Similarly, the
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phrase "if it is determined" or "if [a stated condition or event] is detected"
may be construed to
mean "upon determining" or "in response to determining" or "upon detecting
[the stated condition
or event]" or "in response to detecting [the stated condition or event],"
depending on the context.
[0020] Making reliable electrical connections between tools for while-
drilling applications can
present significant design challenges such as limited space availability and
operability in high
temperatures (e.g., 150 C or greater). Other design considerations include,
but are not limited to,
ruggedness, low cost, and ease of maintenance, even in adverse conditions. The
rotatable, wet-
mateable connector disclosed herein saves time and mitigates operator errors
by simplifying
wellsite tool preparation and configuration assembly and also serviceability
of the connector itself.
The rotatable connector gives designers greater flexibility in usage and
placement. In such
connectors both mechanical and electrical connections occur substantially
simultaneously. A wet-
connector (also known as wet-mateable connector) permits the mating of the
connector
components in the presence of conductive fluid such as impure water or
drilling fluid (mud) by
expelling fluid from the mating cavity and preventing fluid invasion into the
chamber.
[0021] An apparatus and method to provide a mating connector that is
rotatable and wet-
mateable is disclosed herein. The connector has mating components that can be
characterized as
male and female. The connector has one or more electrical contacts and one or
more non-electrical
contacts. As used herein, "wet-mateable" or "wet-connectable" means proper
mating of the male
and female components can be achieved even in the presence of conductive
fluid. Being
"rotatable" means the male and female components can be rotated independently
(i.e., relative to
one another) during the mating process.
[0022] In one embodiment, a female component comprises a one-piece molded
assembly with
contact rings, hookup wires, and certain external features to aid alignment
and installation. Choice
of molding compound may vary depending on application and temperature
requirements. For
example, thermoplastics (e.g., PEEK) or fiberglass composites may be used.
After molding,
secondary machining may be done to ensure the mating cavity is cylindrical and
its surface smooth
enough for 0-ring sealing. The inner diameter surface of embedded contact
rings is exposed to
the connector's central cavity and is an integral part of the cavity's inner
wall. For critical
applications the electrically conductive surface of the contact ring may be
gold plated. Hookup
Date Recue/Date Received 2021-10-05
wires in electrical connection with the contact rings are encapsulated up to
their exit point at one
end of the connector. A weep hole at the bottom of the cavity provides an
escape route for any
trapped fluid.
[0023] Similarly, a mating male component is also a molded assembly with no
moving parts
(other than perhaps a rotational degree of freedom of the conductive 0-ring).
The molding
compound does not have to be identical to its female counterpart, but many of
the same
considerations apply. On the male component's external surface there may be
one or more 0-ring
glands (a sleeve used to produce a seal around a shaft) with widths and depths
appropriate for the
pre-selected 0-ring sizes. The glands that correspond to electrical contacts
have conductive (e.g.,
metallic) surfaces, preferably gold-plated but generally the same as the
corresponding female
contact ring. The desired conductive surfaces can be obtained, for example, by
heavy plating over
the plastic/composite base material or by embedding metal rings. Each
conductive gland is
preferably "sandwiched" between non-conductive glands, but one non-conductive
gland is
sufficient, as described below. For example, a connector with three
electrically conductive glands
may have a total of seven glands with three conductive glands at the "2nd",
"4th", and "6th"
positions, respectively, and four non-conductive glands at the "1st", "3rd",
"5th", and "7th"
positions, respectively. This creates insulating barriers between electrical
contacts. Secondary
machining after molding may be performed to satisfy surface finish and
tolerance requirements.
Hookup wires to the male component's conductive rings/surfaces are
encapsulated up to their exit
end of the connector.
[0024] Elastomeric 0-rings made with non-conductive material such as VITON,
silicone, or
HNBR are installed on the non-conductive glands. One or more conductive 0-
rings (e.g., an
elastomer with a conductive filler such as silver-plated aluminum, an
elastomeric core metallized
on the outer diameter surface, a core spiral wrapped with a metallic strip, or
an expandable metallic
ring that can be installed and deployed like an elastomeric ring) may be
installed on each
conductive gland. The non-conductive 0-rings provide very good fluid and
electrical isolation
between contacts axially, while the conductive 0-rings provide electrical
continuity radially
between corresponding male and female electrical contacts.
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[0025] The smooth, uniform cylindrical female cavity, substantially void of
any protrusions or
irregularities, keeps contaminant buildup to a minimum, facilitates the
removal of fluid trapped in
the chamber, and further facilitates cleaning. During insertion, the leading 0-
ring on the male
component acts as a plunger, pushing out any trapped fluid through a weep hole
and, at the same
time, wiping clean the female contact surfaces.
[0026] The conductive 0-rings can be replaced and conductive glands cleaned
in short order.
If the conductive 0-ring is elastomeric, it is relatively non-abrasive. In
addition to being gentle on
the mating surfaces, it maintains a 360 degree surface-to-surface contact.
This allows for relative
rotation between male and female counterparts without loss of conductivity.
While it is
conceivable that small amounts of conductive fluid can be trapped in the void
space of the 0-ring
glands, that will not be an issue if the electrical contacts are isolated from
other electrical contacts
by adjacent non-conductive 0-rings (i.e., no conductive path between
electrical contacts).
[0027] Figure 1 shows one embodiment of a mating connector male component
100. The male
component 100 comprises a male body 102 having seven 0-ring glands, three of
which are
conductive glands 104, and four of which are non-conductive glands 106. More
or fewer glands
are possible. Each of the conductive glands 104 traps a conductive 0-ring 108,
and each non-
conductive gland 106 traps a non-conductive 0-ring 110. In this embodiment
each conductive
gland 104 has a non-conductive gland 106 on either side of it (i.e., axially
offset). The 0-ring
glands 104, 106 are all disposed on and fixed relative to the male body 102.
Likewise, conductive
0-rings 108 and non-conductive 0-rings 110 are substantially fixed relative to
the male body 102.
That is to say, male component 100 has no moving parts (other than perhaps a
rotational degree of
freedom for an 0-ring). Figure 1 also shows a set of hookup wires 112 and one
of the hookup wire
connectors 114 electrically connected to a conductive gland 104. Each
conductive gland 104 is
similarly connected to its corresponding hookup wire 112 via its corresponding
hookup wire
connector 114.
[0028] Contact elements such as conductive 0-rings 108 and non-conductive 0-
rings 110 are
removable and therefore easily replaced. In addition, when the connector 300
(see Fig. 3) is mated,
non-conductive 0-rings 110 provide fluid isolation barriers, thereby
precluding electrical shorting
via fluid migrating into regions housing the electrically conductive 0-rings
108. As further
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Date Recue/Date Received 2021-10-05
described below, when the male and female connector components mate, fluid is
simultaneously
expelled from the mating cavity through a weep hole 210 (see Fig. 2),
affording a higher level of
connectability in a wet environment.
[0029] Figure 2 shows a mating connector female component 200 corresponding
to the male
component 100 embodiment of Figure 1. The female component 200 comprises a
female body
202 having an open end 204 and an interior chamber 206. Embedded in female
body 202 and
integral to the wall of the interior chamber 206 are three contact rings 208.
More or fewer contact
rings are possible. Thus, female component 200, like its male counterpart 100,
has no moving
parts. Female body 202 has a weep hole 210 at or near the end of chamber 206
opposite the open
end 204. Contact rings 208 are likewise protected from fluid incursion by non-
conductive 0-rings
110 when the connector 300 (see Fig. 3) is mated. A set of hookup wires 212 is
shown. While
not expressly shown in Figure 2, each contact ring 208 is connected to a
corresponding hookup
wire 212. Female body 202 has certain external features 214 that aid in the
mounting and sealing
of the connector 300.
[0030] Figure 3 shows the male component 100 of Figure 1 and the female
component 200 of
Figure 2 in their combined or mated configuration, thereby forming connector
300. Corresponding
elements of male component 100 and female component 200 are shown in their
aligned state. In
particular, each contact ring 208 is paired and in electrical contact with its
corresponding
conductive gland 104 via conductive 0-ring 108. Each contact ring
208/conductive 0-ring
108/conductive gland 104 assemblage, in conjunction with corresponding hookup
wires 112, 212,
forms an electrically conductive path through connector 300, allowing transfer
of electrical power
and/or data (i.e., electrical signal) through the tool train (i.e., bottomhole
assembly). Non-
conductive 0-rings 110, in conjunction with non-conductive glands 106, are in
sealing engagement
with the wall of interior chamber 206. As stated above, these provide
electrical and fluid isolation
to the contact ring 208/conductive 0-ring 108/conductive gland 104
assemblages.
[0031] While the embodiments shown in Figures 1, 2, and 3 have multiple
contact ring
208/conductive 0-ring 108/conductive gland 104 conductive assemblages and
multiple non-
conductive gland 106/non-conductive 0-ring 110 sealing assemblages, only one
of each such
assemblages is required. That is, a non-conductive gland 106/non-conductive 0-
ring 110 pair can
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Date Recue/Date Received 2021-10-05
be placed at the leading end of male component 100 (i.e., the portion to first
enter chamber 206),
and a conductive 0-ring 108/conductive gland 104 pair can be placed "behind"
the non-conductive
gland 106/non-conductive 0-ring 110 pair on male component 100. A
corresponding contact ring
208 is disposed in female component 200. Such an arrangement ensures fluid is
expelled from
chamber 206 and contact ring 208 is wiped clean when making up the connector
300, and will
prevent fluid incursion via the weep hole once the tool is deployed into the
wellbore. An
alternative sealing means (not shown) may be used at or near the opening 204,
but this is not
necessarily crucial if there is only one electrical contact since there are no
other electrical pathways
by which the electrical circuit can be shorted.
[0032] In operation, a male connector component 100 and a female connector
component 200
are provided at a wellsite. Alternatively, male components 100 and female
components 200 may
be pre-installed in tools intended to be disposed in a wellbore. At the
wellsite a drillstring is
fabricated using drillpipe and drill collars housing various downhole tools
forming a bottomhole
assembly. Each tool (or group of interconnected tools within a drill collar)
is a modularized unit,
typically requiring electrical connection above and below when mechanically
assembled into the
bottomhole assembly. For those tools in the bottomhole assembly requiring
electrical connectivity
(e.g., for data or power transmission), male connectors 100 and female
connectors 200 may be
attached to the tools, if not already installed, to facilitate the needed
electrical connections.
[0033] Figure 4 shows one embodiment of a male connector assembly 400 for
an inter-tool (or
inter-module) downhole logging tool (or downhole measurement tool) system used
in oil and gas
exploration. Figure 4 shows the male component 100 disposed in a sleeve 402.
In this embodiment
the sleeve 402 is trapped by a nut 404, securing sleeve 402 and male component
100 to a male
chassis connector 406. Each downhole tool or module typically has a structural
member called a
"chassis" on which instrumentation is mounted. The chassis, in conjunction
with the drill collar
in which the tool is mounted, helps makes the tool capable of withstanding the
extreme downhole
conditions typically encountered. The male connector assembly 400 shown in
Figure 4,
comprising male chassis connector 406 and male component 100, is connected via
male chassis
connector 406 to one end of a downhole tool chassis (not shown) by
conventional means (e.g.,
threaded connector). For example, male chassis connector 406 may be joined to
the lower end of
a downhole tool chassis, thereby locating male component 100 near the lower
end of the enclosing
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Date Recue/Date Received 2021-10-05
drill collar, ready to be mated to a female component 200 mounted similarly on
the upper end of
the next tool lower in the bottomhole assembly. Of course, a reciprocal
arrangement could also
be configured (i.e., female component 200 above, male component 100 below).
[0034] Figure 5 shows a counterpart female connector assembly 500 for an
inter-tool (or inter-
module) downhole logging tool (or downhole measurement tool) system. Female
component 200
is disposed in housing 502. Housing 502 is complementary to sleeve 402 and
sealingly fits within
the interior of sleeve 402. Housing 502 is secured to female chassis connector
504. Female chassis
connector 504 allows for connection of female connector assembly 500 to a tool
chassis in the
same or similar manner as described above for male connector assembly 400. In
LWD (Logging
While Drilling) or MWD (Measurement While Drilling) operations, the male and
female connector
assemblies 400, 500 are each joined to the extremities of respective adjacent
tools (modules) and
centralized within their respective drill collars.
[0035] Figure 6 shows a male connector assembly 400 and a female connector
assembly 500
in close proximity to one another just prior to being joined. Male connector
assembly 400 is joined
to the lower end of a first chassis (not shown) via male chassis connector
406. The first chassis is
disposed in and secured to upper drill collar 602. Similarly, female connector
assembly 500 is
joined to the upper end of a second chassis (not shown) via female chassis
connector 504. The
second chassis is disposed in and secured to lower drill collar 604. As the
upper drill collar 602
and the lower drill collar 604 are rotatingly threaded together (i.e., making
up the bottomhole
assembly, just prior to "tripping in" or running into the hole), the male and
female connectors 100,
200 make up (i.e., join) simultaneously, both mechanically and electrically.
That is, housing 502
rotatingly slides into sleeve 402 and male component 100 rotatingly slides
into female component
200. As male component 100 enters through open end 204 and penetrates chamber
206, fluid in
chamber 206, if any, is displaced and ported to the exterior via weep hole
210. Contact rings 208
are wiped clean as male component 100 moves into chamber 206. When first and
second drill
collars 602, 604 are fully landed, male component 100 is fully inserted in and
properly aligned
with female component 200. Conductive 0-rings 108 make electrical connection
with contact
rings 208, creating the desired electrical pathways. Non-conductive 0-rings
110 are in sealing
engagement with the wall of chamber 206, thereby preventing fluid incursion
into chamber 206
and isolating electrical contact elements 104, 108, 208.
Date Recue/Date Received 2021-10-05
[0036] To ensure such proper alignment and to allow for variations such as
that due to thermal
expansion, male connector assembly 400 has a male sliding member 606 and
female connector
assembly 500 has a female sliding member 608. Each of those sliding members
606, 608 can
telescopically move axially relative to its respective chassis connector 406,
504. Those sliding
members 606, 608 can be held in place, for example, by springs that provide a
force bias but also
allow for relative motion in response to external forces.
[0037] Should an 0-ring contact element 108, 110 become worn or otherwise
damaged, it can
easily be removed and replaced, even in the field. In operation at the
wellsite, the damaged 0-ring
108, 110 is simply removed and a new conductive 0-ring 108 or non-conductive 0-
ring 110, as
the case may be, is placed on male body 102 at the proper corresponding
location. In one example
scenario, an otherwise working drillstring containing a defective rotatable
and wet-mateable
mating connector 300 is removed from a wellbore. When the drill collars 602,
604 containing the
defective rotatable and wet-mateable mating connector 300 are disassembled on
the rig floor, the
male connector assembly 400 is exposed. Nut 404 can be removed to release
sleeve 402, allowing
access to male component 100. Any defective contact elements such as
conductive 0-ring 108 or
non-conductive 0-ring 110 can be removed and replaced. The drill collars 602,
604 can then be
reassembled, and, in doing so, rotatable and wet-mateable mating connector 300
is simultaneously
remade and ready to return downhole with re-established electrical connections
and/or seals.
[0038] While specific embodiments disclosed herein describe particular
structural elements
and materials, non-standard materials or non-circular cross-sections, as well
as other sealing
elements/techniques, may also be used.
[0039] Figure 7 shows a flowchart illustrating an embodiment in accordance
with this
disclosure. In this embodiment, the workflow comprises: providing a male
component of a
rotatable and wet-mateable mating connector that has conductive and non-
conductive sealing
elements (702); providing a female component of the rotatable and wet-mateable
mating connector
having conductive elements that are complementary to the male component (704);
and inserting
the male component into a cavity within the female component to produce the
rotatable and wet-
mateable mating connector (706).
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[0040] The foregoing outlines features of several embodiments so that those
skilled in the art
may better understand the aspects of the present disclosure. Those skilled in
the art should
appreciate that they may readily use the present disclosure as a basis for
designing or modifying
other processes and structures for carrying out the same purposes and/or
achieving the same
advantages of the embodiments introduced herein. Those skilled in the art
should also realize that
such equivalent constructions do not depart from the scope of the present
disclosure, and that they
may make various changes, substitutions, and alterations herein without
departing from the scope
of the present disclosure.
[0041] The Abstract at the end of this disclosure is provided to comply
with 37 C.F.R. 1.72(b)
to allow the reader to quickly ascertain the nature of the technical
disclosure. It is submitted with
the understanding that it will not be used to interpret or limit the scope or
meaning of the claims.
[0042] While only certain embodiments have been set forth, alternatives and
modifications
will be apparent from the above description to those skilled in the art. These
and other alternatives
are considered equivalents and within the scope of this disclosure and the
appended claims.
Although only a few example embodiments have been described in detail above,
those skilled in
the art will readily appreciate that many modifications are possible in the
example embodiments
without materially departing from this invention. Accordingly, all such
modifications are intended
to be included within the scope of this disclosure as defined in the following
claims. In the claims,
means-plus-function clauses are intended to cover the structures described
herein as performing
the recited function and not only structural equivalents, but also equivalent
structures. Thus,
although a nail and a screw may not be structural equivalents in that a nail
employs a cylindrical
surface to secure wooden parts together, whereas a screw employs a helical
surface, in the
environment of fastening wooden parts, a nail and a screw may be equivalent
structures. It is the
express intention of the applicant not to invoke 35 U.S.C. 112(f) for any
limitations of any of the
claims herein, except for those in which the claim expressly uses the words
'means for' together
with an associated function.
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