Note: Descriptions are shown in the official language in which they were submitted.
Attachment Bolt for Portable Manway Cover Hinge
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates generally to "manway" covers for
access
to enclosed spaces such as tanks, conduits, storage areas, heat exchanger
tubes,
strainers, and the like. Particularly, the present invention relates to
attachment
bolts used with mechanisms for handling the removal and installation of
"manway"
covers that are either too hazardous, or too heavy, or too cumbersome to be
handled by an unaided individual.
2. Description of the Prior Art
[0002] Manway covers are typically large, heavy, metal plates that are
bolted
to an opening. For purposes of the present invention, the definition of
"manway
covers" expressly means any heavy covers or closures used on pressure vessels,
vacuum vessels, atmospheric vessels, heat exchangers, heat exchanger channel
covers, heat exchanger channels, heat exchanger bonnets, heat exchanger shell
covers, dished heads, domed heads, half covers such as on divided water box
heat exchangers, chiller condensers, chiller heat exchangers, chiller coolers,
inspection ports, strainers, or any type of blanking plate and is not
construed to be
limited to only covers used on openings that are dimensionally-sized to allow
passage of a man. The most common are circularly-shaped and mate to a flange
by way of a plurality of bolts evenly spaced around the periphery of the
opening.
However, it should be understood that the heavy covers may be any shape. The
defined manway covers typically provide access to enclosed spaces such as
tanks, conduits, storage areas, transfer tubes, pressure vessels, vacuum
vessels,
atmospheric vessels, heat exchangers, heat exchanger channel covers, heat
exchanger channels, heat exchanger bonnets, strainers, and the like. These
types of covers are typically found in power plants, co-generation power
plants,
steam generation plants, chemical plants, petrochemical plants, refineries,
pharmaceutical plants, air separation plants, beverage plants, food processing
plants, heating and cooling facilities, buildings with central heating and
cooling
systems, buildings with chiller cooling systems, water treatment plants, waste
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management plants, dairies, tank farms, gas storage facilities, liquid natural
gas
storage facilities, manufacturing facilities and or any facility that has
tanks,
vessels, piping, heat exchangers, chillers, boilers, turbines, strainers,
and/or
equipment of similar nature.
[0003] Routine servicing and inspection requirements as well as other
operating conditions necessitate periodic removal of these covers. In view of
the
typical location and weight of the covers, it is not a simple task to remove
the
cover or to re-install the same. Removal is currently accomplished with the
use of
hand operated davit swing arms, chain falls, ratchet hoists, and brute force.
Except for davit swing arms, it is necessary during the removal process to
lower
the covers a distance to a level surface.
[0004] Various devices have been devised to facilitate manway cover removal
and re-installation. Figures 1A, 1B and 10 illustrate one such prior art
device.
Fig. 1A is a perspective cover view of hinge plate 30 attached to cover 4.
Fig. 1B
is a perspective flange view of hinge plate 20 attached to flange 2. Fig. 160
is an
outside perspective view of hinge 10 where cover 4 is in an open position
relative
to flange 2. A linkage member 40 is attached to the pair of elongated hinge
plates
20, 30 where each of the hinge plates 20, 30 has one or more hinge plate
openings 22, 32 for aligning with corresponding manway flange and manway
cover openings. A pivot connection 50 pivotally connects linkage member 40 of
hinge plate 20 to linkage member 40 of hinge plate 30, which permits hinge
plates
20, 30 to pivot relative to each other and which are configured to swing
manway
cover 4 away from manway opening 6 providing access to the inside of the
manway structure. In this embodiment, an optional cutout or notch 12 provides
access to cover bolts not originally removed for attaching hinge 10 to cover 4
and
flange 2. An alternative to a cutout or notch 12 is a plurality of apertures
that are
located in hinge plates 20, 30 that coincide with cover/flange bolts.
[0005] A manway cover 4 is attached to a manway flange 2 with a plurality of
bolts 5. The manway flange 2 is permanently affixed to an access tube 3 that
typically leads to a much larger internal space such as, for example, a tank.
A
portable manway hinge device 10 is attachable to and removable from the
manway cover 4 and the manway flange 2 using the cover bolts, other standard
bolts, or specially-designed expansion bolts. The bolts are inserted from the
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outside surfaces of the manway cover 4 and the manway flange 2. Figure 2 is an
enlarged partial top view of the removable and portable manway hinge 10 having
a flange hinge plate 20 and a cover hinge plate 30 attached to the manway
flange
2 and manway cover 4, respectively. The bolts 5 are inserted into the
respective
flange and cover bolt openings to secure the hinge plates 20, 30 to the manway
flange 2 and cover 4.
[0006] U.S. Patent No. 8,038,031 (2011, DePietro et al.) discloses a
portable
manway cover hinge device. The hinge device has a pair of hinge plates where
each hinge plate has a support member with a hinge aperture positioned for
alignment with a bolt opening of a manway cover and a manway flange, a linkage
member adjacent a first end of each hinge plate and extending out of the plane
of
the hinge plate, and a pivotal connection coupling overlapping pairs of the
linkage
member of the pair of hinge plates.
[0007] U.S. Patent No. 8,784,024 (2014, Lison et al.) discloses a pull-
up bolt
assembly for frictionally supporting a high-weight structure to a hinge
component
using an opening or recess in the high-weight structure. The bolt assembly
includes a pull-up bolt member having a threaded shaft with a first shaft end
and a
second shaft end, and an abutting member with a tapered surface formed at the
first shaft end, the abutting member being wider than and tapering toward the
threaded shaft, a nut component with an external torque-applying surface
threadably connected to the threaded shaft, a tapered member with a tapered
end
portion and a flange formed between the external torque-applying surface of
the
nut component and the tapered end portion wherein the tapered end portion
faces
toward the tapered surface of the abutting member, and an expandable friction
member disposed around the threaded shaft between the abutting member and
the tapered member whereby the expandable friction member expands when the
nut component is threadably moved toward the abutting member of the pull-up
bolt member.
[0008] The prior art devices are a vast improvement over the conventional
options available for removing manway covers. So long as there was sufficient
space to be able to insert the standard bolts or expansion bolts into both the
cover
and the flange for securing the portable manway cover hinge, the prior art
removable manway hinge is remarkably useful.
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SUMMARY OF THE INVENTION
[0009] The portable manway cover hinge has provided an easy and convenient
way for removing and/or installing, supporting, and/or storing a manway cover.
The portable manway cover hinge has also made it possible for use in confined
or
congested areas to remove and/or install, support, and/or store a manway
cover.
The portable manway cover hinge has further made it possible for one man to
handle, support, store, and install a manway cover.
[0010] Notwithstanding the advantages of the portable manway cover
hinge,
there has always been the disadvantage that the portable manway cover hinge
could only be used on manway covers where the manway flanges have sufficient
access to the bolt holes on the outside (i.e. back) surfaces of the manway
flange
to insert the bolts that secure the hinge plates of the portable manway cover
hinge
to the cover and, particularly, the flange. Unfortunately, there are many
manway
covers that cannot attach the manway hinge in this way.
[0011] It is an object of the present invention to provide an attachment
bolt for
a portable manway cover hinge for manway covers that have restricted space
behind the flange where standard bolts or expansion bolts typically used for
attaching the hinge plates to the manway flange cannot be used.
[0012] The present invention achieves these and other objectives by
providing,
in combination, an attachment bolt and a portable manway hinge where the
attachment bolt is configured to permit attaching the portable manway hinge to
a
manway flange where there is restricted space behind the manway flange to
allow
use of standard attachment bolts and/or pins. In one embodiment, the manway
hinge includes a pair of hinge plates adapted for attaching one of the pair of
hinge
plates to an outside, back surface of a manway flange and the other of the
pair of
hinge plates to an outside front surface of a manway cover where each hinge
plate has at least one hinge plate opening positioned for alignment with a
bolt
opening of the manway cover and the manway flange, as the case may be, and a
specially-designed attachment bolt for connecting the one of the pair of hinge
plates to the manway flange. The attachment bolt has a threaded portion, a
hinge
plate portion, and a retaining pin. The threaded portion has a first threaded
end
and a second threaded end where the first threaded end is adapted for
receiving a
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bolt turning tool to thereby move the threaded portion into and out of a
threaded
flange bolt opening. The hinge plate portion has a diameter smaller than a
minor
diameter of the threaded portion and it extends from the second threaded end a
predefined distance to a distal hinge portion end. The hinge plate portion has
length sufficient to extend through the hinge plate opening in the one of the
pair of
hinge plates positioned against the outside surface of the manway flange. The
distal hinge portion end has a transverse opening for receiving therein a
portion of
the retaining pin so that the retaining pin retains the hinge plate against
the
manway flange when the threaded portion is turned to retract the hinge plate
portion into the flange bolt opening.
[0013] In another embodiment, the first threaded end of the attachment
bolt
has a slot that is transverse to the first threaded end where the transverse
slot is
adapted for receiving a straight screwdriver tool whereby the tool is used to
insert
and/or retract the attachment bolt.
[0014] In a further embodiment, the first threaded end of the attachment
bolt
has either a male extension or a female recess adapted for receiving one of an
allen-tipped tool, a star-tipped tool, a phillips-tipped tool, and a flat-
tipped tool.
[0015] In still another embodiment of the present invention, there is
described a
method of installing a portable manway hinge to a manway flange that is
connected to an access tube where the spacing between the manway flange and
an outer surface of the access tube is reduced and/or restricted so that bolts
and/or hinge plate securing pins cannot be inserted from the backside of the
manway flange. The method includes removing a plurality of manway cover bolts
from a portion of the manway cover and manway flange, providing a portable
manway cover hinge that has a pair of hinge plates where each hinge plate has
at
least one hinge opening positioned for alignment with a bolt opening of the
manway cover and manway flange, and aligning a hinge plate opening of the
hinge plate with one of the plurality of bolt openings of the portion of the
manway
cover and the manway flange from which the bolts were removed. The method
further includes inserting a specially-designed attachment bolt into one of
the bolt
openings of the manway flange through the corresponding manway cover bolt
opening a sufficient distance where the attachment bolt extends beyond the
outside, back surface of the manway flange a distance greater than the
thickness
Date recue/date received 2021-10-28
of the hinge plate to be attached to the manway flange. The method also
includes aligning a hinge plate opening of the hinge plate with one of the
plurality
of bolt openings of the portion of the manway cover and the manway flange from
which the bolts were removed and in which the attachment bolt was inserted and
positioning the hinge plate against the manway flange. Once the hinge plate is
aligned, then the method requires inserting a removable retaining pin into a
transverse opening of the hinge plate portion of the attachment bolt followed
by
retracting the attachment bolt to a point in the flange bolt opening so that
the
retaining pin retains the hinge plate against the manway flange. The other of
the
pair of hinge plates is then attached to the manway cover by aligning the
hinge
plate aperture(s) with the corresponding manway cover aperture(s), inserting a
pin
into each hinge aperture and securing each pin within the corresponding cover
bolt opening.
[0016] The method further includes providing a specially-designed
attachment
bolt having a threaded portion and a hinge plate portion connected to the
threaded
portion where the threaded portion has a length smaller than the length of the
manway flange opening such that the threaded portion always remains within the
manway flange opening when the attachment bolt is retracted to cause the
retaining pin to retain the hinge plate against the manway flange.
[0017] The specially-designed attachment bolt has a threaded portion
with a
first threaded end and a second threaded end. The hinge plate portion has a
diameter smaller than a minor diameter of the threaded portion where the hinge
plate portion extends from the second threaded end to a distal hinge plate
portion
end where the distal hinge plate portion end has the transverse opening
through
the hinge plate portion. During the inserting step, the attachment bolt is
inserted a
sufficient distance whereby the transverse opening extends beyond the hinge
plate aperture of the one of the pair of hinge plates. To be clear, the hinge
plate
portion has a length to accommodate the thickness of the hinge plate between
the
transverse opening and the second threaded end of the threaded portion.
[0018] For manways having split covers, it is contemplated that the
present
invention may also be used with two portable manway hinge devices. In one
embodiment, the optional component is a hinge connector that connects one
hinge member of one hinge device to a serially-aligned hinge component of an
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adjacent hinge device. The hinge connector may be attached between the two
serially aligned hinge components using alignment pins, threaded rods,
securing
brackets, and the like. In another embodiment, the optional component is a
leveling member connected at or adjacent one end of the hinge device. The
leveling member on the flange hinge member may be aligned for contact with the
peripheral edge of the flange or with the manway extension connected to the
flange. The leveling member on the cover hinge member is aligned for contact
with the peripheral edge of the cover.
[0019] In yet a further embodiment of the present invention, there is
described
a specially-designed attachment bolt. The attachment bolt has a threaded
portion,
a hinge plate portion and a removable retaining pin. The threaded portion has
a
first threaded end and a second threaded end where the first threaded end is
adapted for connecting a bolt turning tool to thereby move the threaded
portion
into and out of a threaded flange bolt opening. The threaded portion also has
a
length that will be completely contained within a corresponding manway flange
opening in which it is used to securely hold a hinge plate of a manway hinge
against the manway flange. Because the manway flange opening is threaded, the
hinge plate portion has a diameter smaller than a minor diameter of the
threaded
portion and extends from the second threaded end a predefined distance to a
distal hinge portion end. The distal hinge portion end has a transverse
opening
through the hinge plate portion where the hinge plate portion is adapted to
extend
through an attachment bolt opening in a hinge plate of the portable manway
hinge
and adapted to provide a length between the second threaded end and the
transverse opening sufficient to position the transverse opening beyond the
hinge
plate. The removable retaining pin is insertably disposed within the
transverse
opening of the hinge plate portion whereby the removable retaining pin retains
the
hinge plate against the manway flange when the threaded portion is turned to
retract the hinge plate portion into the flange bolt opening.
[0020] In another embodiment of the attachment bolt, the attachment bolt
has
slot in the first threaded end that is transverse to the first threaded end.
[0021] In still another embodiment of the attachment bolt, the first
threaded end
of the attachment bolt has either a male extension or a female recess adapted
for
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Date recue/date received 2021-10-28
receiving one of an allen-tipped tool, a star-tipped tool, a phillips-tipped
tool, and a
flat-tipped tool.
[0022] In another aspect, there is provided in combination, a portable
manway
hinge device and an attachment bolt for securing the portable manway hinge
device to a manway flange connected to an access tube where spacing between
the manway flange and the access tube is restricted, the combination
comprising:
the portable manway hinge device comprising: a pair of hinge plates adapted
for
attaching one of the pair of hinge plates to an outside back surface of the
manway
flange and the other of the pair of hinge plates to an outside front surface
of a
manway cover wherein each of the pair of hinge plates has a hinge plate
opening
positioned for alignment with a bolt opening of the manway cover and the
manway
flange; and an attachment bolt assembly having the attachment bolt and a
removable retaining pin for connecting the one of the pair of hinge plates to
the
manway flange, the attachment bolt comprising: a threaded portion having a
first
threaded end and a second threaded end, the first threaded end adapted for
receiving a bolt turning tool to thereby move the threaded portion into and
out of a
threaded manway flange opening; and a hinge plate portion having a diameter
smaller than a minor diameter of the threaded portion and extending from the
second threaded end a predefined distance to a distal hinge portion end
sufficient
to extend through a hinge plate opening in the one of the pair of hinge plates
positioned against the outside back surface of the manway flange, the distal
hinge
plate portion end having a transverse opening through the hinge plate portion,
wherein the removable retaining pin is insertably disposed within the
transverse
opening of the hinge plate portion whereby the retaining pin retains the hinge
plate
against the manway flange when the threaded portion is turned to retract the
hinge plate portion into the manway flange opening.
[0023] In another aspect, there is provided a method of installing a
portable
manway hinge device to a manway flange connected to an access tube where
spacing between the manway flange and the access tube is restricted, the
method
comprising: providing a portable manway cover hinge having a pair of hinge
plates
wherein each of the pair of hinge plates has a hinge plate opening positioned
for
alignment with a bolt opening of a manway cover and a manway flange; removing
a plurality of manway cover bolts from a portion of a manway cover whereby the
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Date recue/date received 2021-10-28
plurality of manway cover bolts are selected to align with the position of the
hinge
plate opening of each of the pair of hinge plates; inserting a specially-
designed
attachment bolt into a manway flange opening through the corresponding manway
cover opening whereby the specially-designed attachment bolt extends beyond
the outside, back surface of the manway flange a distance greater than a
thickness of one of the pair of hinge plates, the specially-designed
attachment bolt
having a threaded portion with a first threaded end and a second threaded end,
and a hinge plate portion having a diameter smaller than a minor diameter of
the
threaded portion wherein the hinge plate portion extends from the second
threaded end to a distal hinge plate portion end wherein the distal hinge
plate
portion end has a transverse opening through the hinge plate portion, the
specially-designed attachment bolt being inserted a sufficient distance
whereby
the transverse opening extends beyond the hinge plate opening of the one of
the
pair of hinge plates; aligning the hinge plate opening of the one of the pair
of hinge
plates with one of a plurality of bolt openings of the portion of the manway
cover
and the manway flange from which the plurality of manway cover bolts were
removed and in which the specially-designed attachment bolt was inserted and
positioning the one of the pair of hinge plates against the manway flange;
inserting
a removable retaining pin into the transverse opening of the hinge plate
portion of
the specially-designed attachment bolt; retracting the specially-designed
attachment bolt to a point in the manway flange opening whereby the removable
retaining pin retains the one of the pair of hinge plates against the manway
flange;
inserting a standard attachment pin into each hinge opening of one of the pair
of
hinge plates connected to the outside front surface of the manway cover and
corresponding manway cover opening; and securing each standard attachment
pin within the corresponding manway cover opening.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGURE 1A is a perspective view of one embodiment of the manway
hinge of the prior art attached to a manway flange and manway cover showing
the
manway cover in a closed and supported position.
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Date recue/date received 2021-10-28
[0025] FIGURE 1B is a perspective view of one embodiment of the manway
hinge of the prior art attached to a manway flange and manway cover showing
the
back side of the manway flange and a portion of an access tube.
[0026] FIGURE 10 is a perspective view of one embodiment of the manway
hinge of the prior art attached to a manway flange and a manway cover showing
the manway cover in an open position.
[0027] FIGURE 2 is a partial side view of the prior art arrangement of
the hinge
plates and retaining bolts connected to a manway flange and a manway cover.
[0028] FIGURE 3 is a partial side view of the arrangement of the hinge
plates
and the attachment bolt of the present invention connected to a manway flange
having restricted space between the manway flange and the access tube.
[0029] FIGURE 4 is a back, perspective view of the present invention
attached
to a hinge plate on the back side of the manway flange showing the removable
retaining pin.
[0030] FIGURE 5 is a perspective view of one embodiment of the attachment
bolt of the present invention.
[0031] FIGURE 6 is a side view of the attachment bolt shown in Fig. 5.
[0032] FIGURE 7 is a front view of the attachment bolt shown in Fig. 5.
[0033] FIGURE 8 is a top view of one embodiment of the attachment bolt
of the
present invention showing a tool receiving end.
[0034] FIGURE 9 is a top view of one embodiment of the attachment bolt
of the
present invention showing another embodiment of a tool receiving end.
[0035] FIGURE 10 is a distal end view of the attachment bolt of the
present
invention.
[0036] FIGURE 11 is a partial side view of the attachment bolt of the
present
invention assembled through manway flange and a hinge plate showing the
relationship of the attachment bolt structure to the manway flange bolt
opening
and the hinge plate.
[0037] FIGURE 12 is a partial side view of the attachment bolt of the
present
invention assembled through manway flange and a hinge plate showing the
relationship of the attachment bolt structure to the manway flange bolt
opening
and the hinge plate after engagement of the attachment bolt, the hinge plate
and
the manway flange.
Date recue/date received 2021-10-28
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0038] In the present disclosure, certain terms will have particular
meanings.
The term "allen-tipped tool" means any tool that has a tip portion configured
as a
male extension or female recess having a shape similar to that known in the
art as
an allen wrench configuration. The term "star tipped tool" means any tool that
has
a tip portion configured as a male extension or female recess having a shape
similar to that known in the art as a torx wrench configuration. The term
"phillips-
tipped tool" means any tool that has a tip portion configured as a male
extension
or female recess having a shape similar to that known in the art as a phillips
screwdriver configuration. The term "flat-tipped tool" means any tool that has
a tip
portion configured as a male extension or female recess having a shape similar
to
that known in the art as a flat screwdriver configuration.
[0039] The present invention is illustrated in Figs. 3-12. Figure 3
illustrates the
use of a portable manway cover hinge 10 on a manway. Hinge 10 includes a pair
of elongated hinge members 20, 30, a linkage member 40 and a plurality of
support members 40. Elongated hinge member 20 is connected to a manway
flange 52 and the elongated hinge member 30 is connected to the peripheral
edge
of manway cover 54. Linkage member 40 is attached to the pair of elongated
hinge members 20, 30 and a pivot connection 50 pivotally connects linkage
member 40 of hinge plate 20 to linkage member 40 of hinge plate 30, which
permits hinge plates 20, 30 to pivot relative to each other and which are
configured to swing manway cover 54 away from manway opening 6 (not shown)
providing access to the inside of the manway structure. A plurality of pins 5
secure hinge plates 20, 30 to a plurality of bolt holes such as manway flange
opening 52a and manway cover opening 54a in manway flange 52 and manway
cover 54, respectively. What is notable about Fig. 3 is the shape of the
manway
access tube 56 connected to manway flange 52. The manway access tube 56
flares outward to a larger diameter over a relatively short length of manway
access tube 56. This widening configuration of manway access tube 56 restricts
the space behind and between manway flange 52 and access tube 56 such that
the conventional attachment bolts 5 cannot be inserted from the back of manway
flange 52. The present invention provides a specially-designed, hinge
attachment
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bolt assembly 100 for the manway flange 52, which will be described later. As
shown in Fig. 4, attachment bolt assembly 100 includes a removable retaining
pin
130 through distal end portion 110 of attachment bolt 102. Retaining pin 130
prevents hinge plate 20 from disengaging with attachment bolt 102 and secures
hinge plate 20 to manway flange 52.
[0040] Turning now to Figures 5-10, there is illustrated various
embodiments of
specially-designed attachment bolt assembly 100. Fig. 5 is an expanded view of
attachment bolt assembly 100. Attachment bolt assembly 100 includes an
attachment bolt 102 and a removable pin 130. Attachment bolt 102 has a
threaded portion 112, a hinge plate portion 110, a transverse opening 122 in a
distal hinge plate portion end 120, and a removable retaining pin 130.
Threaded
portion 112 has a thread diameter and pitch that matches the threads formed in
a
manway flange opening 52a and a length that is shorter than a thickness of
manway flange 52. In fact, the length of threaded portion 112 must allow for
assembling hinge plate 20 onto manway flange 52 and hinge plate portion 110
and then securing hinge plate 20 to manway flange 52 all the while keeping
threaded portion 112 completely within manway flange opening 52a. Removable
retaining pin 130 has a diameter that is slightly smaller than the diameter of
transverse opening 122 so that retaining pin 130 is easily inserted into
transverse
opening 122 but maintains a close fit to reduce play between the outer surface
130a of retaining pin 130 and the inner surface 122a of transverse opening
122.
The length of retaining pin 130 must also be greater than the length of the
transverse opening 122 and greater than the diameter of the hinge plate
openings
through which hinge plate portion 110 extends so that opposite ends 132, 134
of
retaining pin 130 extend across portions of hinge plate 20 to retain hinge
plate 20
against manway flange 52.
[0041] Fig. 6 is a side view of the embodiment of attachment bolt 102
shown in
Fig. 5. Attachment bolt 102 has threaded portion 112 with a first threaded end
114 and a second threaded end 116. In this embodiment, first threaded end 114
has a bolt slot 122 formed into first threaded end 114 where bolt slot 122 is
transverse to threaded portion 112. Bolt slot 122 is adapted for receiving a
tool
such as a flat-tipped screwdriver so that attachment bolt 102 may be inserted
into
and retracted out of manway flange bolt opening 52a. Although bolt slot 122 is
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Date recue/date received 2021-10-28
shown extending in substantially the same direction as transverse opening 122
in
hinge plate portion 110, bolt slot 122 doesn't have to be but may be
positioned at
any angle relative to transverse opening 122.
[0042] Fig. 7 is a front view of attachment bolt 102. As can be seen,
transverse opening 122 extends completely through hinge plate portion 110.
Hinge plate portion 110 has a diameter A that is smaller than the thread minor
diameter B of threaded portion 112. The diameter A of hinge plate portion 110
being smaller than the thread minor diameter B is critical so that hinge plate
portion 110 can pass through manway flange opening 52a and does not interfere
with the internal threads of manway flange opening 52a, which threads are
adapted to mate with the external threads of thread portion 112.
[0043] Fig. 8 is a top end view of one embodiment of attachment bolt 102
having a bolt slot 122 formed into first threaded end 114. Bolt slot 122 is
sized to
accept a flat-tipped tool such as a flat end screwdriver and the like. Fig. 9
is a top
end view of another embodiment of attachment bolt 102 having a bolt recess 123
formed into first threaded end 114. Bolt recess 123 is sized to accept an
alien-
tipped tool such as an alien wrench and the like. It is contemplated that
first
threaded end 114 may have any male extension or female recess adapted for
receiving one of an allen-tipped tool, a star-tipped tool, a phillips-tipped
tool, and
flat-tipped tool formed into or onto first threaded end 114 to accommodate a
tool
having a corresponding tool end that is used to insert and/or retract
attachment
bolt 102 in manway flange opening 52a.
[0044] Fig. 10 is bottom end view of the attachment bolt 102 shown in
Fig. 5.
As shown, distal hinge portion end 120 has a diameter A that is smaller than
thread minor diameter B.
[0045] Turning now to Figure 11, there is illustrated a cross-sectional
view of
the manway flange opening 52a with one embodiment of the attachment bolt
assembly 100 of the present invention. Manway flange opening 52a has an
internal thread for receiving the manway cover bolts that secure the manway
cover 54 to the manway flange 52. Attachment bolt 102 is positioned within
manway flange opening 52a such that threaded portion 112 is adjacent the
outside, back surface 53 of manway flange 52. Hinge plate portion 110 extends
through hinge plate opening 22 of hinge plate 20 so that hinge plate 20 is
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positioned between manway flange 52 and transverse opening 122 of hinge plate
portion 110. Removable retaining pin 130 extends through transverse opening
122.
[0046] Figure 12 illustrates a cross-sectional view of the manway flange
opening 52a with attachment bolt assembly 100. In this illustration,
attachment
bolt 102 is re-positioned within manway flange opening 52a so that removable
retaining pin 130 disposed within transverse opening 122 captures hinge plate
20
against the outside back surface 53 of manway flange 52.
[0047] A method of using the present invention will now be disclosed.
Although the present invention is designed to address the problem with limited
space behind the manway flange 52 that is connected to an access tube that
flares outwardly and has a larger circumferential distance at the connection
point
to the tank than at the connection point to the manway flange 52, it is
contemplated that the present invention may also be used for conventional
manway cover/manway flange configurations or where the access tube has
constant circumferential distance but that the manway flange is so close to
the
tank that the space behind the manway flange 52 is so restricted that standard
securing bolts and/or pins used for attaching manway hinge 10 to manway flange
52 cannot be used.
[0048] The method involves providing a portable manway cover hinge 10 that
has a pair of hinge plates 20, 30 where each hinge plate 20, 30 has a hinge
aperture 22, 32, respectively. Hinge apertures 22, 32 are located in hinge
plates
20, 30 for alignment with a corresponding bolt opening 52a, 54a of manway
flange
52 and manway cover 54. A plurality of manway cover bolts 5 are removed from
a portion of manway cover 54 where the plurality of manway cover bolts 5 are
selected to align with the position of the hinge plate apertures 22, 33 of
hinge
plates 20, 30. Once removed, the specially-designed attachment bolt 102 is
inserted into each manway flange opening 52a through the corresponding
manway cover opening 54a. Attachment bolt 102 is inserted into each manway
flange opening 52a with hinge plate portion 110 being inserted first followed
by
threaded portion 112 so that hinge plate portion 110 extends beyond the
outside,
back surface 53 of the manway flange 52 a predefined distance that is greater
than the thickness of hinge plate 20. Threaded portion 112 is threaded into
14
Date recue/date received 2021-10-28
manway flange opening 52a to a point so that there is a sufficient length of
hinge
plate portion 110 to accommodate hinge plate 20 between transverse opening
122 and the outside, back surface 53 of manway flange 52 to allow insertion of
removable retaining pin 130 into transverse opening 122. Next, hinge plate 20
is
assembled onto attachment bolt 102 by aligning hinge plate aperture 22 of
hinge
plate 20 with hinge plate portion 110 and sliding hinge plate 20 against the
outside, back surface 53 of manway flange 52. Because attachment bolt 102 was
inserted to accommodate hinge plate 20 between transverse opening 122 and the
outside, back surface 53 of manway flange 52, removable retaining pin 130 is
now
inserted into transverse opening 122 so that substantially equal portion of
removable retaining pin 130 extends from opposite sides of hinge plate portion
110. Alignment bolt 100 is then retracted (i.e. unscrewed) from its position
so
that removable retaining pin 130 captures hinge plate 20 against the outside,
back
surface 53 of manway flange 52 to thereby hold hinge plate 20 securely against
manway flange 52. Threaded portion 112 has a predefined length so that
threaded portion 112 remains completely within manway flange opening 52a after
securing hinge plate 20 against the outside, back surface 53 of manway flange
52.
[0049] It is contemplated that the order of attachment bolt 102
insertion into
manway flange opening 52a and the assembling of the hinge plate 20 by aligning
the hinge plate opening 22 with the manway flange opening 52a may be reversed
or switched. That is, one could align the hinge plate opening 22 with the
manway
flange opening 52a and then insert the attachment bolt 102 into the manway
flange opening 52a.
[0050] Although various embodiments of the present invention have been
described herein, the above description is merely illustrative. Further
modification
of the invention herein disclosed will occur to those skilled in the
respective arts
and all such modifications are deemed to be within the scope of the invention
as
defined by the appended claims.
Date recue/date received 2021-10-28
