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WRA-33176
APPARATUS FOR STRAPPING ITBMS HY MEANS OF BANDS
The present invention relates to an apparatus for strapping
items by means of tensioning bands, in particular for
strapping pulp bales by means of paper bands, having
arrangements for conveying the tensioning bands around the
items, and =or tensioning the bands and f.-or connecting the
'tensioned bands enclosing the. items.
Such an apparatus, which is known, for example from US-A 5 560
180, has a guide channel which fully encloses the respective
item and through which a tensioning band is pushed, as a
result of :which the band is guided around the item, whereupon
it is then tensioned. The guide channel is designed, on the
side which is directed toward the item, with swing-action
elements which open as soon as the band is tensioned, as a
result of which the tensioning band passes into abutment
against the item and can then be joined together.
This known apparatus, however, does r_ot satisfy requirements
since the tensioning band has t o have a high level of rigidity
in order to be able to be pushed through the guide channel. In
addition, in particular on account of the swing-action
elements, the guide channel constitutes a component which is
of complex design and in which, in addition, functioning may
be disrupted since the band can jam in the channel or get
stuck on the swing-action elements as the latter are opened.
T,he object of the present invention is thus to provide an
apparatus in which the disadvantages associated with the known
apparatus are avoided. This is achieved according to the
invention in that the conveying arrangement is farmed by a
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drawing arrangement, e.g. a belt, which encloses the
respective item, is designed with a carry-along element and is
assigned a drive arrangement by means of which the CarryTalong
element can be moved around the item.
Since the tensioning band is drawn around the item, it may
have a lower level of rigidity than if it is pushed through a
guide chanr_el. In addition, disruptions to functioning are, to
the greatest~exterit, avoided. Furthermore, it is possible for
'the tensioning band to be guided around 'the item with a small
spacing therefrom, as a result of which 'the operation of
bracing it requires lower outlay than irl the case in the known
apparatus. This additionally rules out twisting of the band
during the tensionir_g operation.
The drawing arrangement is advantageously guided over a
plurality of, in particular four, deflecting rollers, at least
one of the deflecting rollers being assigned a drive. In this
case, the drawing arrangement is designed, in particular, as a
toothed belt.
According to a preferred embodiment, the carry-along element
has two clapping jaws which can be adjusted in relation to one
another, axe located laterally outside the belt, in the
movement direction of the latter, and between which the
tensioning band can be clamped. It is possible here for the
two clamping jaws to be subjected to the action of a spring, -
by means of which they are kept in their closed position, arid
it is possible fo,r the carry-along element to be assigned an
actuating arrangement by means of which the clamping jaws can
be adjusted into their open, position, as a result of which a
band can be introduced between them. The carry-along element
is preferably designed with two clamping jaws, a first
clamping jaw is fastened on the belt or the like and the
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second clamping jaw can be adjusted in relation to the first
clamping jaw. It is possible here for the first clamping jaw
to be provided with a through-passage through which a bolt or
the like projecting from the second clamping jaw passes, the
actuating spring enclosing the bolt or the like, and this also
being assigned the actuating arrangement. Furthermore, the
carry-along element is preferably assigned a channel through
which the tensioning band can be pushed toward the carry-along
element, there being provided for the tensioning band a
clamping arrangement by means of which the tensioning band can
be displaced in relation to the conveying channel.
According to further preferred features, the installation also
contains a tensioning arrangement for the band, an adhesive-
b,onding arrangement for the band, a pressing arrangement for
the bard ar_d a cutting arrangement. It is possible here for
the clamping arrangement and the adhesive-bonding arrangement
to be arranged on a carriage which can be displaced counter to
the advancement direction of the tension~.ng band ror strapping
the item, and for the first clamping arrangement to be
assigned a second, fixed clamping arrangement.
An apparatus according to the invention is explai:~ed in more
detail hereinbelow with reference to an exemplary e_nbodiment
illustrated in the drawing, in which:
Figure 1 shows an axonometric illustration of an installation
for strapping items by means of tensioning bands with an
apparatus for applying and tensioning the bands;
Figures 2 and 2a show two side views of the apparatus for
applying and tensioning the bands;
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Figures 3 to 6 show the apparatus according to Figure 2 in
four different operating positions;
Figures 7 and 7a show a detail of this apparatus in a side
view, partly in section, and in elevation;
Figures 8 to 10 show a constituent part of this apparatus in
three success-ve operating positions and in side view;
Figures 11, 12 and 13 show further constituent parts of this
apparatus, in elevation and in different operating positions;
and
Figures 11a and 13a each show a side view of these further
constituent parts.
The installation illustrated in figure 1 for strapping items
by means of tensioning bands 20 has an apparatus l for
applying the tensioning bands 20 around items 10 and a
conveying apparatus, e.g. a roller conveyor la, by means of
which the items 10 are fed to the apparatus 1.
As can further be seen from figure 2, the apparatus 1 has a
rectangular carrying framework 11, at the four corners of
which deflecting rollers 12, 12a are mounted, a drawing
arrangement in the form of a toothed belt 2 being positioned
around said deflecting rollers. The deflecting roller 12a is
assigned a drive 13. A carry-along element 3 for a tensioning
band is arranged on the belt 2. The carry-along element 3 is
actuated by a control arrangement 4. xhe drive 13 rotates the
deflecting roller 12a, as a result of which the belt 2 is
moved and the carry-along element 3 is guided, in the
direction of the arrow A, around the item 10 which is to be
strapped.
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As can further be seoen from figure 2a, the deflecting and
drive roller 12a is coupled for carry-along action with the
drive 13 va a belt 13a: It can also be seen that the carry-
along element 3 is designed with two clamping jaws 31 and 32
which project laterally from the conveying belt 2 and are
assigned the control arrangement 4. As soon as the two
clamping jaws 3~ and 32 are located in their open position,
the front end of a tensioning band can be introduced between
them, said tensioning band then being guided around the item
10, as is explained hereinbelow with reference to figures 3 to
6.
As can further be seen f ram figures 3 to 6, the apparatus J. is
assigned a band store 20a from which a tensioning band 2D is
drawn off by means of a conveying and tensioning arrangement 5
and moved in the direction of the carry-along element 3. Also
provided are an adhesive-bonding arrangement 6, a pressing
arrangement 7 and a cutt'r_g arrangement 8, the design and
functioning of which are explained hereinbe~.ow.
As is illustrated schematically in figures 4 to 6, the
tensioning band 20 is guided around the item 10 by means of
the carry-.along element 3 until it encloses said item to the
full extent and butts loosely against the same. It is then
tensioned around the item 10 and joined together by adhesive
bonding. Thereafter, the item 10 is transported further.
As can be seen from figures 7 and 7a, the carry-along element
3 is designed with a carrying plate 30, which is fastened on
the conveying belt 2 by means of a clamping plate 21 and bolts
22. The first clamping jaw 31 is fastened rigidly on the
carrying plate 30. In contrast, the second clamping jaw 32 is
fastened an a push rod 33, which passes through a bore 34 of
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the carrying plate 30 and is subjected to the action of a
compression spring 35. The push rod 33 is assigned a push rod
41 of the opening arrangement 4. As soon as the push rod 41 is
adjusted upward, the second clamping jaw 32 is lifted off from
the first clamping jaw 31 counter to the action of the
compression spring 35, as a result of which the front end of
the tensioning bard 20 can be pushed in between the two
clamping jaws 31 and 32. Once the push rod 41 is restored, the
tensioning band 20 is regained between th,e two clamping jaws
31 and 32, as a result of which it can be: guided around the
item 10 by the carry-along element 3,
Figures 8 to 13 will be used hereinbelow to explain the
construction and the fur_ctioning of the conveying and
tensioning arrangement 5 far the tensioning band 20, of the
adhesive-bonding arrangement 6, of the pressing arrangement 7
and of the cutting arrar_gernent 8.
As can be seen from figures 8 to 10, the conveying and
tensioning arrangement 5 has a conveying channel 51, 51a for
the tensioning band 20, at being possible for the part 51a to
be pivoted by means of an actuating cylinder 52, and also has
a further actuating cylinder 53 and a first clamping
arrangement 54, which can be displaced in relation to the
conveying channel 51 by means of the actuating cylinder 53. In
order to introduce the tensioning band 20 between the clamping,
jaws 31 and 32 opened by means of the control arrangement 4,
the clamping arrangement 54 is set in operation and displaced
in the direction of the arrow B by means of the actuating
cylinder 53, as a result or which the free end of the
tensioning band 20 is pushed in between the clamping jaws 31
and 32 through the conveying channel 51 and through the part
51a. The carry-along element 3 is then moved around the item
to the full extent by means of the conveying belt 2.
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Thereafter, the movable part of the conveying channel 51a is
pivoted away from the carry-along element 3 in the direction
of the arrow C by means of the actuating cylinder 52.
As can be seen from figure 11, thereafter, the front- end of
the tensioning band 20 is secured by means of the carry-along
element 3, the first clamping arrangement 54 is closed and the
actuating cylinder 53 is activated such that the tensioning
band 20 is drawn back in the direction of the arrow D by means
~of the first clamping arrangement 54. The tensioning band 20
is then tensioned around the item 10. As can further be seen
from figure 11, the conveying and tensioning arrangement S as
well as the adhesive-bonding arrangement 6 are borne by a
carriage 50, which can likewise be displaced in the direction
of the arrow D by means of a drive 50a. As can be seen from
figure 12a, the adhesive-bonding arrangement 6, which is
designed with an adhesive-bonding nozzle 61, can be pushed in
beneath the tensioned bard 20, guided around the item 10, from
one side, in Lhe direction of the arrow E, by means of an
actuating cylinder 62. It can be further be seen =rom figure
lla that the conveying channel 51 is formed by two rails which
contain grooves and between which the first clamping
arrangement 54 and a second clamping arrangement 55 fox the
band 20 come to act on the latter.
Then, as is illustrated in figure 12, the first clamping
arrangement 54 is opened, the second clamping arrangement 55 '
is activated and the carriage 50 is displaced in the direction
of the arrow D. During the displacement operation, adhesive is
applied, by the adhesive-bonding nozzle 61, to that end of the
tensioning band 20 which is guided around the item 10.
Displacement of the carriage 50 in the direction o~ the arrow
D causes the ends of the tensioning band 20 to overlap, with
the adhesive between them.
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As can also be seen from figure 13, a pressing arrangement 7
and a cutting arrangement 8 are also provided. By means of the
pressing arrangement 7, those sections o.f the tensioning band
20.which are located one upon the other are pressed together.
As can be seen from figure 13a, the pressing arrangement 7 has
a framework 70, on which a pressing cylinder 71 with a piston
72 is mounted in a pivotable manner. A pressing plate 73 is
articulated on the piston 72. The pressing plate 73 is
assigned a mating plate 74, which is located between the item
and the two sections 20a, 20b of the tensioning band 20. As
soon as the piston 72 is adjusted by means of the pressing
cylinder 71, the pressing plate 73 is adjusted in the
direction o. the mating plate 74, as a result of which the two
sections 20a, 20b of the tensioning band 20, between which
adhesive is located, are pressed.
Following ce.<<pleticn oL the pressing operation, the cutting
arrangement 8, which is arranged at the end of the conveying
channel 51a, is set in operation, as a result of which the
tensioning band 20 is cut off. Thereafter, the item 10 is
moved laterally, as a result of which the tensioning band 24
is released from the pressing plate 73 and the mating plate
74, and the item is transported away by means of the roller
conveyor la. It is then possible to strap a further item 10
fed by means of the roller conveyor la.
Such an apparatus is used for strapping any desired item. A
preferred application is the operation of strapping pulp
bales.
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