Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF T~IE INVENTION
The present invention relates to a device for handling
steel bars and sections, in particular tubes, arranged in
planar bundles.
It is known that the handling of steel bars and sections,
such as tubes, shows a considerable number of inconveniences,
in particular with respect to the safety of the handling
operators and due to the noise caused in the environment.
- At present elongated metallic articles as above-mentioned are moved from a store to another or during the loading
operation or discharging from a transportation means sub-
stantially according to two dlfferent methods.
A first manner of moving elongated steel sections is
based on the utilization of an electromagnet carried by
a usual hoisting apparatus which attracts and keeps at-
tracted one or more pieces being preferably bundled, during
the steps of taking and moving, and lets them drop at the
place of arrival.
Pivotable safety arms have been then coupled to the
electromagnet, which are vertically movable with respect to
the electromagnet in order to prevent the pieces from drop-
ping and to keep them hold even in case of power failure and
incidental deenergization of the electromagnet. It is known
that, according to this type of procedure, further personnel
on the ground is required to properly arranye the metallic
elements, in addltion to the operator of the hoisting apparatus.
Another method of handling elongated metallic axticles
includes bundling a certain number of pieces together by
means of blndlng ropes, thus creatlng a bundle of art~lcles
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which is subsequently moved as a single block on bearing
arms or by hanging hooks of a hoisting apparatus, such as
a crane or a conventional self-propelled means.
Both the above-mentioned transportation systems have
the drawback of being excessively noisy in the discharge
operation owing to the mutual collisions and the rolling
of the pieces, which may also cause damages to the surface
of the pieces being dischar~ed. These systems are par-ticu-
larly disadvantageous when piling up elongated metallic ele-
ments~ This operation must be effected in layers, eachlayer of articles being separated by those disposed there-
under by means of wooden spacers or girders to the purpose of
a proper arrangement of the articles and to obtain a suffi~
cient gap for the insertion of the binding ropes or bearing
arms of the hoisting apparatus. The piling up of these
elongated metallic elements requires further personnel for
inserting and removing the spacers from the pile of elements
and, in case of breakage of the spacers, falls or displace-
ments of the articles may occur, which are harmful to the
material and disadvantageous for further possible transpor-
tations.
Summar~ Of The Invention
It is the object of the present invention to provide a
device for handling steel bars or tubes and structural steel
which allows to overcome the above-mentioned inconveniences
at the same time reducing as much as possible the sources
of noise, while eliminating the need of further personnel
in addition to the crane operator and allowing the safe
transportation of tubes without the danger of incidental
falls thereof.
The device of the invention comprises: a support frame
to be hooked to a hoisting apparatus; at least two pairs
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of bearing and fastening arms, which are pivotally mounted
to said frame; at least one pair of planar electromagnets,
movable wlth respect to said arms and provided with slits
through which metallic blocks may project and caused to
be retracted in order to attract a plurality of pieces to
be transported in the form of a layer; and means for lifting
and lowering said electromagnets with respect to the support
frame.
In the following description of an illustrative embodiment
of the device, particular reference will be made to the hand-
ling of circular cross-section steel tubes, which show the
highest number of the mentioned inconveniences. However it
should be obvious that the invention may also be applied to
articles of ferromagnetic metal, in particular of steel,
having a different configuration, such as bars, rods, sheets
or plates of reduced width and in general having an elongated
shape.
Brief Description of _ e Drawinys
The device according to the present invention will be more
fully understood by the following detailed description of an
embodiment, given by way of a non-limiting example, with
reference to the annexed drawings, in which:
FIGURE 1 is a perspective view showing the device with
open arms during an operation of taking up or laying down a
layer of tubes;
FIGURE 2 is a perspective view of the same device with
closed arms during a transportation step; and
FIGURE 3 is a cross-section view of an electromagnet at
the moment of coming into contact with a layer of tubes to
be handled.
Deta_led Description of the Preferred Embodiment
With particular referenceto Figs. 1 and 2, the device of
the in~ention comprises a supporting f~ame, generally indlcated
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1, being connected to a hoisting apparatus which may be a
common crane, such as of the known bridge type, thus not
being illustrated in detail.
Again with reference to Figs. 1 and 2, and also to Fig.
3, the device comprises a pair of electromagnets 8 positioned
under the supporting frame. Each electromagnet 8 has a sub-
stantially parallelepiped shape, of convenient size and is
formed with inner slits for housing metallic blocks 4 which
may project or be retracted, thus completely matching with
the surface of articles or tubes 18 to be handled.
Each electromagnet 8 is conventionally (not illustrated)
connected to an electric power source in the hoisting ap-
paratus. The controls for energization and deener~ization
of the elec-tromagnets 8 may be advantageously installed in
the driver's cab, where the handlin~ operator thus can di-
rectly control also this operation.
According to one of the main fehtures of the invention~
the electromagnets 8 are not fixed on the support frame 1,
but are vertically movable with respect thereto.
The device of the present invention comprises arms 17
provided for co-operating with the electromagnets 8 to secure
the metallic pieces to be handled~ i.e. the steel tubes 18
in the illustrated case. In the illustrated embodiment the
securing arms 17 are in number of four, ~ut a different
number could be provided, in particular a higher one, de-
pending on the lenyth of the tubes 18.
~s shown in Figs. 1, 2 each arm 17 is formed with a L-
shaped metallic bar with a vertical side 19 and a horizontal
side 20. An end of the side 19 of the securing arms 17 is
pivotally inserted in a hole formed in the support frame.
Such an end is held within this hole to allow the side 19
to rotate therein and at the same time to preven-t the same
from escaping from the hole.
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The rotation of the arms 17 is obtained by known means
adapted to move the arms 17 from a rest position ~shown in
Fig. 1) to the work position (Fig. 2). In the first position
of the arms, the electromagnets 8 are allowed to move either
downward or upward, whereas in the second position the arms
together with the electromagnets 8 are capable of securing
the tubes 18.
In operation the side 20 of each arm 17 posi-tions itself
under the electromagnets 8 so that these sides 20, with the
corresponding lower faces of the electromagnets heavily lying
on the tubes 18, from a number of "pincers" for securely
gripping the tubes. The ends of the side 20 of each pair
of arms 17, during the operation, are almost in contact wi-th o~e
another, thus preventing even tubes of very small diameter
from escaping and falling down.
The operation of the device according to the invention
is the following, when supposing to star-t from the rest posi-
tion of Fig. 1, where the electromagne-ts 8 are deenergized
and placed at a lower level than the sides 20 of arms 17,
with respect to the support frame. In this position the
electromagnets 8 are thereby projecting from the device.
The crane driver then operates the hoist means supporting
the device to move down until the electromagnets 8 come into
contact with the tubes 18. When the electromagnets 8 rest
onto the tubes 18l the downward movement of th~ l~olsting ap-
paratus is automatically stopped. The operator, upon checking
the correct positioning of the electromagnets 8 with respect
to the tubes 1~, actuates the energization oE the electro-
magnets 8 and then again the liEting of the hoist means.
The lifting is carried out in two stages. In a first
time the stroke of the hoist is rather short, such as to
cause the layer of tubes 18 to lift by few centimeters being
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attracted by the electromagnets. This initial stroke is to
ascertain that -the layer of tubes 18 is kept attracted by the
electromagne-ts 8. At the end of this first path a motor (not
shown) is operated, which drives the electromagnets to lift.
As the electromagnets 18 are completely retracted in the
device, arms 17 are caused to rotate in order to posltion
their portions 20 under the tubes 20 in the work position
shown in Fig. 2.
The hoisting apparatus is at this moment operated again,
thus beginning the second lifting step during which a down-
ward stroke of the electromagnets 8 is caused to be ~fEected.
This downward stroke continues until the tube 18 comes into
contact with the sides 20 of arms 17.
In this position, with the supporting cables slightl~
slack, the still energized electromagnets 8 rest by their
weight on ~he tubes 18 thus securing these against the arms
17. In this way, since the electromaynet weight is high,
any possible movement of the tubes 18 parallel to their longi-
tudinal axes is avoided and any one or more of the tubes 18
are prevented from escaping the device.
At the end of the lifting stroke r the operator actuates
the motor for the horizontal movement in order to position
the device of the invention over the discharge zoneO Upon
reaching this zone, he carries out the operations required
to discharge the tubes 18.
The downward stroke is stopped as soon as the device
according to the invention has approached the layer of tubes
already laid down in the preceding operation or the plane on
which the tubes 18 must be discharged.
Subsequently the electromagnets 8 are caused to move up-
ward again until the tubes 18 are clear of -the arm portions
20 and the arms 17 can return again to the rest position
(Fig. 1). The electromagnets 8 are then caused to move down-
ward to reach the position illustrated in Fig. 1 t under the
sides 20 of the arms 17.
At this stage a further lowering of the whole device is
operated until the layer of -tubes 18 comes into contact with
the surface below and then, subsequently, the supporting
cables or ropes are released, the electromagnets are deener-
gized and the handled tubes lie down with the minimum noise
on the discharge place.
Thereafter a new charging operation may begin, which
takes place as above-described. All the operations for
loading tubes, subsequent to the energization of electromagnets
8, may be carried out only if the energization has been actu-
ally e~fected ~mder the prescribed conditions and with the
predetermined current values. Thus the device of the inven-
tion may be lifted only if the tubes 18 are actually a-ttrac-
ted by the electromagnets.
Furthermore the charge and discharge of -the tubes is
carried out in such conditions that any source of noise is
eliminated. This because the handled tubes are not positioned
randomly, but are arranged side by side to form a layer which
may be laid down easily, without rolling on or impacting
against the previously discharged layer.
It should finally be appreciated that all the handling
operations are carried out by the crane driver or in general
the operator oE the hoisting apparatus. Therefore the pre-
SenGe of only one person is required, with a strong reduc-tion
of the labour costs and without any further personnel on the
ground, who was before the most subject to accidents with
the handling devices of the prior art.
All above described can of course be extended to the case
of elongated ferromagnetic articles, in particular of steel,
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having whichever cross-section~ such as bars, rods and the like,
without exceeding the inventive concept of the present device.
Other additions and/or modifications may be made to the de-
vice according to the invention withou-t departing from the
protective scope of the invention itself, as de-fined in the
appended claims.
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