LIFTING LUG FOR TANKS AND THE LIKE

OREILLE DE LEVAGE POUR RESERVOIRS ET AUTRES DU MEME GENRE

English Abstract

A lifting lug apparatus comprises a mounting plate adapted for attachment to an upper portion of an object to be lifted. A lifting lug defines a hook aperture and is pivotally attached to the mounting plate such that the hook aperture is movable from a lateral position, wherein the hook aperture is oriented in a lateral plane extending outward from the mounting plate and outward from an attached object to be lifted, to an upright position, wherein the hook aperture is oriented in an upright plane extending upward from the mounting plate. The lifting lug is biased toward the lateral position so that a lifting hook can conveniently be engaged in the hook aperture, and when the object is lifted the lifting lug pivots upward to reduce stress on the connection between the lifting lug and the object.

French Abstract

Une oreille de levage comprend une plaque de montage adaptée pour être fixée à une partie supérieure d'un objet à lever. Une oreille de levage définit une ouverture pour crochet et est fixée de manière à pivoter à la plaque de montage pour que l'ouverture pour crochet soit déplaçable d'une position latérale, dans laquelle l'ouverture du crochet est orientée dans un plan latéral s'étendant vers l'extérieur de la plaque de montage et vers l'extérieur à partir d'un objet fixé à lever, jusqu'à une position verticale, dans laquelle l'ouverture pour crochet est orientée dans un plan vertical s'étendant vers le haut à partir de la plaque de montage. L'oreille de levage est retenue vers la position latérale pour qu'un crochet de levage puisse facilement être engagé dans l'ouverture pour crochet, et lorsque l'objet est levé, l'oreille de levage pivote vers le haut pour diminuer la contrainte sur la connexion entre l'oreille de levage et l'objet.

Claims

CLAIMS:
What is claimed is:
1. A lifting lug apparatus comprising:
a mounting plate adapted for attachment to an upper portion of an object to be
lifted;
a lifting lug defining a hook aperture, the lifting lug pivotally attached to
the
mounting plate such that the hook aperture is movable from a lateral position,
wherein the hook aperture is oriented in a lateral plane extending outward
from
the mounting plate and outward from an attached object to be lifted, to an
upright
position, wherein the hook aperture is oriented in an upright plane extending
upward from the mounting plate;
wherein the lifting lug is biased toward the lateral position.
2. The apparatus of Claim 1 wherein the lifting lug is biased toward the
lateral
position by a counterweight attached to the lifting lug.
3. The apparatus of Claim 2 wherein the counterweight comprises a plate
extending
laterally from the lifting lug and configured such that the plate bears
against one
of the mounting plate and the object to lifted when the lifting lug is in the
lateral
position.
4. The apparatus of any one of Claims 1 - 3 wherein the lifting lug is
pivotally
attached to the mounting plate about a substantially horizontal pivot axis.

5. The apparatus of any one of Claims 1 - 4 wherein the mounting plate is
adapted
for attachment to the object to be lifted such that when the lifting lug is in
the
upright position, the hook aperture is above a top edge of the object to be
lifted.
6. A tank apparatus comprising:
a tank comprising a substantially upright wall and a top attached to a top
edge of
the wall;
a lifting lug defining a hook aperture, the lifting lug pivotally attached to
an upper
portion of the wall such that the hook aperture is movable from a lateral
position,
wherein the hook aperture is oriented in a lateral plane extending outward
from
the wall, to an upright position, wherein the hook aperture is oriented in an
upright plane extending upward above the top edge of the wall;
wherein the lifting lug is biased toward the lateral position.
7. The apparatus of Claim 6 wherein the lifting lug is biased toward the
lateral
position by a counterweight attached to the lifting lug.
8. The apparatus of Claim 7 wherein the counterweight comprises a plate
extending
laterally from the lifting lug and configured such that the plate bears
against the
wall when the lifting lug is in the lateral position.
9. The apparatus of any one of Claims 6 - 8 wherein the lifting lug is
pivotally
attached to the upper portion of the wall about a substantially horizontal
pivot
axis.
10. The apparatus of Claim 9 wherein the lifting lug is pivotally attached to
a
mounting plate about the substantially horizontal pivot axis, and the mounting
plate is attached to the upper portion of the wall.

Description

CA 02491715 2008-06-11
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LIFTING LUG FOR TANKS AND THE LIKE
This invention is in the field of lifting and tnoving large tanks and like
objects, and in
particular mechanisms for attaching a lifting apparatus to the objects.
RACKGROUNl7
It is well known to attach a crane or like lifting apparatus to large objects
to raise and
lower such objects. In the nil industry for exanlple, large storage tanks are
conunonly
located at well-sites to store oil bearing fluids pumped from underground
reservoirs.
Such tailks arc typically located inside containment enclosures which comprise
raised
walls opcrativc to contain thc stored fluid in the event that the tank lcaks.
Thus to move a
tank into or out of the contairunent enclosure, a crane is required to raise
the tank and
swing in or out as required.
In a typical tank, lifting lugs are provided at loeations spaced around the
top of the tank,
each lug providing an aperture for attaching a hook on the end of a cable from
the crane.
The lugs are typically welded on the top of the tank wall and extend above the
top of the
tank and define an aperture above the top of the tank. The tanks are quite
tall, and in
addition to requiring a crane when a tank is to be lifted, a separate vehicle
with a man-lift
is required as weil to raise a person to each lug to insert the hook through
the aperture in
the lug.
SU11Il1IARY OF TI-JE INYEIVTION
It is an object of the present invention to provide a lifting lug for
attachment to a large
IE? 11J06/Z008 f017103 -;,~Furman Kallio Qreceivetl

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is required as well to raise a person to each lug to insert the hook through
the aperture in
the lug.
SiT1VII1-'IARY OF THE INVENTION
It is an object of the present invention to provide a lifting lug for
attachment to a large
object to facilitate attachment of a lifting hook that overcomes problems in
the prior art.
Prior art lifting lugs are configured such that the aperture is oriented in a
substantially
vertical plane that substantially coincides with the tank wall, and so a
person is required
in order to nianipulate the lifting hook into the aperture.
The lifting lug of the present invention is pivotally attached to the top of
the tank wall
and counterweighted such that the aperture is ordinarily oriented in a
substantially
horizontal plane. A tag line is attached to the hook from the crane cable, and
the person
remainirig on the ground can then rnanipulate the hook under the horizontal
aperture, and
the hook: can be raised and enter the aperture. As the hook is raised further
it pulls up on
the lug and the lug pivots to a conventional position with the aperture in a
vertical plane,
and lifting proceeds as with the conventional tugs.
If the lug was fixed with the aperture in a horizontal plane extending out
from the tank,

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considerable bending forces would be exerted on the tank wall. By pivoting
into the
conventional position with the aperture in a vertical plane coincidental with
the tank wall,
the forces on the tank wall are substantially the same as with the
conventional fixed lug.
In a typical lifting situation with a large object such as a tank, a main
cable will be
positioned above a center of the tank, and a number of secondary cables will
extend at an
angle from the main cable to lifting lugs spaced around the top of the tank.
With the
pivoting lug of the present invention, the lug can move past the vertical
position and align
itself with the angle of the secondary cable, thereby reducing stress on the
lug and tank.
Thus a separate man-lift vehicle is not required when moving tanks with the
lug of the
present invention, significantly reducing the cost of the move.
DESCRIPTION OF THE DRAWINGS:
While uhe invention is claimed in the concluding portions hereof, preferred
embodiments
are provided in the accompanying detailed description which may be best
understood in
conjunction with the accompanying diagrams where iike parts in each of the
several
diagrams are labeled with likc numbers, and where:
Fig. 1 is a front view of a lifting lug of the present invention in the raised
position
with the aperture oriented in a vertical plane;

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Fig. 2 is a cross-sectional view along line 2-2 in Fig. 1;
Fig. 3 is a side view of the lifting lug of Fig. 1 in the lowered position
fixed to a
tank wall with the aperture oriented in a horizontal plane, and showing a hook
under the aperture thereof;
Fig. 4 is a schematic side view of a tank with lifting lugs of the present
invention
attached at the top end thereof, and showing a main crane cable and secondary
cables attaching the lugs to the main cable.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS:
Figs. 1-- 3 illustrate a lifting lug 1 of the present invention. In the
illustrated embodiment
the liftirig lug is shown mounted on a tank such as that used at oil well
sites for storage of
production fluid, however it is contemplated that the lifting lug could
provide benefits
when mounted on other large and high objects.
A mounting plate 4 is adapted for attachment to the top of a tank wall 6 by
welding or
like known means. A rod 8 is bent in a U-shape and is pivotally attached to a
substantially horizontal pivot shaft .10 by pivot plates 12 welded to ends of
the rod 8. The

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U-shaped rod 8 thus defines a hook aperture 14. The pivot shaft is attached to
the
mounting plate 4 by pivot brackets 16.
A counterweight 18 is attached to the pivot plates 12 and extends away from
the
mounting plate 4, as illustrated. The weight of the counterweight 18 maintains
the U-
shaped rod 8 in the down position illustrated in Fig. 3, where the hook
aperture 14 is
orienteld in a substantially horizontal plane. In the illustrated embodiment,
the
counteiweight 18 is configured and oriented to bear against the pivot brackets
16, as
illustrated in Fig. 3, to support the U-shaped rod 8 so that the hook aperture
14 is oriented
in an approximately horizontal plane. Atternatively, a stop could extend from
the
counterweight 18 and bear against the mounting plate 4, and further
alternatively those
skilled in the art will readily recognize and implenient other means for
maintaining the
hook aperture 14 in the required approximately horizontal orientation.
A person on the ground can then readily maneuver the hook 20 under the
horizontally
oriented hook aperture 14 with a tag line 22 attached to the hook 20. Once the
person has
maneuvered the hook 20 under the hook aperture 14, the person can signal the
crane
operator to raise the hook 20 and engage the U-shaped rod 8. As the hook 20
moves
upward, the U-shaped rod 8 will move from the down position of Fig. 3 to the
up position
of Fig. 2, and further upward movement of the hook 20 will raise the tank.
Thus it is not

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requirrd to raise a person to the lifting lug in order to engage a hook in the
Eifting lug to
raise a tank.
As illustrated in Fig. 4, the lifting lugs i of the present invention can be
readily mounted
spaced around the top of a tank 28 in order to raise the tank 28 without
tipping in a
manner similar to that of the prior art. Fig. 4 shows a main crane cable 24
and secondary
cables 26 extending at an angle from the main cable 24 to lifting lugs 1
spaced around the
top of the tank 28. With the pivoting lug 1, the U-shaped rod 8 can move past
the vertical
position and align itself with the angle of the secondary cable 26, thereby
reducing stress
on the lug 1 and tank 28.
The foregoing is considered as illustrative only of the principles of the
invention.
Further, since numerous changes and modifications will readily occur to those
skilled in
the art, it is not desired to limit the invention to the exact construction
and operation
shown and described, and accordingly, all such suitable changes or
modifications in
structure or operation which may be resorted to are intendcd to fall within
the scope of
the clainied invention.

Representative Drawing