Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
The presen-t invention rela-tes to a depalletiser
or a palletiser, that is to say a machine tor unloading
tiers of goods from a pallet onto a take-of~-sur~ace
or for loading goods onto pallets ~rom a supply surface.
In British Patent Specification ~o. 1~94832, there
is described a depalletiser for unloading tiers of goods ~
from a pallet onto a take-off surface which comprises a ~ i
vertically movable platform, lifting means for aligning ¦
the platform sequen-tially with the individual tiers and
with the take-off surface and transfer means movable _
with the platform for transferring the goods of
successive tiers from the pallet to the platform when
the platform is aligned with each respective tier and
from the platform to the take-off surface ~hen the
platform is aligned with the take-off sur~ace.
'~h~ above patent application also teaches the
p~ovision of means for steadyin~ the tier of goods
immediately below the uppermost tier so as to stea~y
the stack of goods on the pall~t during transfer of
the uppermost ~ier. It is necessary to stead~ the
pallet as th~ goods are being t;rans~erred in order
to prevent the whole pallet from being upset~ ~he
means for steadying the tier o~ goods immediately
below the uppermost tier comprise a pair of pla-tes ` A~ ¦
, 25 depending from the platform and movable la-terally to ~ ¦ `
I steady the next-to-uppermost tier.
A problem encountered with the apparatus described
in the above application resides in the ~act
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that the plates for locating about the next-to-uppermost tier
constituted an obstruction preventing the table from being
lowered down to ground level, so that it was not possible to
support a pallet directly on the ground and transfer the goods
from the lowermost tier onto the table.
With a view to mitigating the disadvantage in the
machine described in British Patent Specification No. 1,494,832,
in accordance with the present invention, the plates for
locating about the next-to-uppermost tier are movable vertically
relative to the platform. This may either be achieved by
arranging the gripping plates to be pivotable about the
horizontal axis upon reaching a lowermost position or by mounting
them for sliding movement relative to the platform.
In ~ritish Patent SpeciEication No. 1,494,~32, when
the platform onto which the goods are transf~rred from the pallet
is brought into alignment with a take-off surace, a flap is
lowered in order to bridge the gap between the platform and
the take-off surface. A further br:idge was provided between
the pallet and the platform which entailed accurate positioning
of the pallet in relation to the platform in order for smooth
transfer to be achieved.
In order to overcome the above disadvantage, in
accordance with a preferred embodiment of the present invention, `
the platform is movable not only vertically
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for alig~nent with the respective tiers of a pallet but
also horizontally in order to bring the platform into
engagement ~ith the respective tiers and subsequently
into alignment with the take-off surface.
The invention will now be described further, by ~Yay
of example, with reference to the accompanying drawings,
in which:-
Figure 1 is a side elevation of a depalletiser in
accordance with the invention,
Figure 2 is an end elevation of the depalletiser
in Figure l, and
Figure 3 is a plan view.
In the drawings, there is shown a depalletiser
genorally designated 10 wllich removes successive tiers
12, 1~, etc. from a pa11et 16 ancl transfers tllem to a
take-off surface which is not sholYn. The take-off surface ~ `
in practive may be the conveyor belt of a factory line or
an accumulating table~ A small fixed transfer platform 18
is provicled at the height of the take-off surface.
The depalletiser includes a table or plat-~orm 2~
which is mounted on a subframe generally designated 22.
The subframe 22 is movable vertically on a pair of columns
2~ by means of a motor 26 which is connected to the subframe
22 by means of a suitable transmission. For example, the
sub~rame 22 may be raised and lowered by means of a chain
powered by the motor 26 or a screw jack serving to drive
the subframe 22 vertically may be clriven by the motor 26.
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The platform 20 is itself movable horizontally
relative to the sub~rame 22, the horizontal movement
being achieved by means of a hydraulic jack ~2 shown
in Figure 3.
A transfer mechanism generallv designated 40 is
providad for transferring goods from the pallet onto
the platform 20 and subsequently from the platform 20
onto -the take-off surface. ~he transfer m~chanism
comprises a sweep arm 42 which is supported by means
of a strutt 28 and bearings 30 on a horizontal rail L~
which is movable with the subframe 22. r~he sweep arm .
42 is driven by a chain mech~mism .not sho~n in detail
which is in t~lrn powered by an electric motor 46
supported on the rail L~.
An arm 48 for steadying a tier o~ goods during .
its transfer is mounted on an adjustable telescopically
collapsible extension 50 for mo~ement with the sweep arm
42. Wnlen transferring -tall bot-tles, or the like, the
arm 48 serves to prevent the row o~ bottles at -the fron-t
end o~ a tier ~rom toppling whilst it is being advanced
b~ means o~ the sweep arm 42.
In order to steady the tier 14 whils-t goods from -the
tier 12 are ~eing transferred onto -the platform 20, pla-tes
60 are arranged on each side o~ the pallets 16 and are
movable laterally, to grip the pallet, by means of arms
62 ~hich are connected -to a hydraulic jack (not shown)
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arranged beneath the table 20. The plates 60 are pivotable
mounted by means of a univPrsal joint 64 for movement in and
out of the plane of the drawing of Figure 1 to grip the pallet
16 and they are additionally pivotable at the joint 64 about
an axis perpendicular to the plane of Figure 1, the plates
adopting the position illustrated in Figure 1 by virtue of their
own weight. The joints between the plates 60 and the arms 62
which serve to move the plates laterally are also designed to
permit vertical movement of the plate 60.
In operation of the machine shown in the drawings
a pellet 16 is placed into position. The height of the sub-
frame 22 is then adjusted by operation of the motor 26 until the
platform 20 is level with the uppermost tier 12. This position
can either be determined by means of an operator on hand or
automatically i sensors are provided, in a conventional manner,
to detect the :Level of the uppermost tier. The platform 20 is
then moved horizontally to close any gap between itself and
the uppermost tier 12. The plates 60 are then brought together
by operation of the jack connected to the plate 60 via the arms
62, so that the arm 60 move laterall~r and grip the sides of
the pallet.
When the table is correctly positioned and the pallet
16 suitably steadied by the plates 60, the sweep arm 42 moves
from left to ri~ht as viewed in Fi~ure 1 to sweep the goods
on the uppermost tier onto the platform 20. The
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space between the sweep arm 42 and the steadying arm 48 is
adjusted by means of the telescopically collapsible tube 50
so that during this transfer the arm 48 serves to steady the
front row of articles being transferred.
When all the goods of the uppermost tier are arranged
on the platform 20, the plates 60 release the pallet 16 and
the platform is moved away from the pallet and is lowered to
aliyn with the smaller platform 18. The platform 20 is again
moved horizontally and finally the sweep arm 42 continues its
sweep to transfer the goods from the platform 20 onto the
conveyor belt or accumulating table, as the case may be.
The above set of operations is repeated to transfer
the next-to-uppermost tier, and so on until the lowermost tier
is reached.
When transferriny ~oods from the lowermost tier onto
the platform 20, during the descent of the platform 20 a
microswitch is operated in a lowermost position of the platform
20 which operates a servomotor, preferably a pneumatic motor,
to cause the plates to pivot about the joints 64 an~ not there-
fore impede the descent of the platform 20. It will be notedthat the plates 60 have an inclined :Lower edge and this is so
that this edge should lie just above and parallel to the floor
when the platform 20 attains its lowermost position.
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l;ihilst the invention has been described with
reference to a depalletiser, it should be app~eciated
that the machine, with minor modifications, can operate
in reverse as a palletiser, -there being substantially
no significant struc-tural difference between the two
machines.
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