Note: Descriptions are shown in the official language in which they were submitted.
CA 02277253 1999-07-09
226P 1 CA
BALE WRAP RETAINING APPARATUS
The present invention relates to bale wrap retaining apparatus for use in bale
wrapping
machines, to bale wrapping machines and to methods of wrapping bales and is
useful in
particular, but not exclusively, for temporarily retaining partially folded
wraps on bales of
paper pulp.
In a conventional pulp bale wrapping apparatus, a covering sheet is firstly
wrapped around
a bale, with portions of the covering sheet folded against opposite sides of
the bale, and the
bale is then advanced to a first tying machine, at which a first wire is tied
around the bail and
its wrap in order to retain the wrap against the opposite sides of the bale.
The thus partially
wrapped bale is then advanced along a path of travel and is either rotated
through 90 degrees
or is passed through a change of direction of 90 degrees and advanced further
to a folding
machine, at which projecting portions of the wrap are folded against opposite
ends of the
bale. The thus-wrapped bale is then advanced to a second tying machine, at
which the
second wire is tied around the bale, at right angles to the first wire, in
order to retain the wrap
folds against the opposite ends of the bale.
It is a disadvantage of this prior bale wrapping apparatus that it causes the
consumption of
a substantial amount of stainless steel wire, which it is subsequently
inconvenient for the end
user to remove. Also, a punch used to secure the wrap to the bale will punch
the wrap itself
and, thus, cause breakage of the wrap, allowing contamination of the pulp in
the bale.
In another type of conventional pulp bale wrapping apparatus, glue, instead of
a wire, is
employed to retain the wrap. More particularly, glue is applied to the wrap
which is then
folded and pressed against the sides of the bale, and the bale is then
advanced to an end
folder, where the ends are glued and then folded and pressed against the ends
of the bale.
The disadvantage of this apparatus is that the bale must remain stationary
while the glue
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dries, which produces a bottleneck in the production process. Modern mills act
at fast speeds
and require correspondingly fast bale wrapping, and the mill operators are
therefore reluctant
to employ such a slow system.
It is an object of the present invention to provide a novel and improved bale
wrap retaining
apparatus which enables a wrap to be retaining partially around a bale while
the bale is
advanced to an end folding machine.
According to the present invention, there is provided a bale wrap retaining
apparatus
comprising a track extending along a path of travel of a bale, a bale wrap
retainer device, and
a suspension movable along the track and suspending the bale wrap retainer
device from the
track, the suspension being operable to move the bale wrap retainer device
between a raised
position, in which the bale wrap retainer device is spaced upwardly from the
bale, and a
lowered position, in which the bale wrap retainer device is in gripping
engagement with a
1 S wrapper on the device.
With the present apparatus, only one length of wire is required to be tied
around the bale in
order to secure the wrap on the bale. Consequently, the first length of wire,
which was
required in conventional prior art machines to retain the partially wrapped
cover sheet
material on the bale, is no longer required. This saves not only the cost of
this first length of
wire and of tying it around the bale but also the cost to the end user of
removing it from the
bale.
In an embodiment of the present invention, the suspension comprises helical
tension springs
biassing the bale wrap retainer device from the lowered position towards the
raised position
and bellows which are expansible to displace the bale wrap gripping device
towards the
lowered position against the action of the springs.
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Preferably, the bale wrap gripping device comprises a support having opposite
ends, a bale
wrap retainer member at each of the opposite ends of the support and pivot
connections
between the bale wrap retainer members and the opposite ends of the support,
the support
extending transversely of the track and the bale wrap retainer members
comprising angle
s shaped plates.
Also according to the present invention, a bale wrap retaining apparatus
comprises a track
extending along a path of travel, wrap gripping means for gripping engagement
with a wrap
on a bale and suspension means suspending the wrap gripping means from the
track, the
suspension means being moveable to and fro along the track and the suspension
being
operable to lower the wrap gripping means onto the bale to retain the wrap in
position on the
bale during the advance of the bale along the path of travel.
Further according to the present invention, a method of wrapping a bale
comprises the steps
of dispensing a wrapper to form a wrap around the bale, moving a wrap retainer
into
engagement with the wrap to retain the wrap in position on the bale, advancing
the bale
together with the wrap retainer along a path of travel while maintaining the
wrap retainer in
retaining engagement with the wrap, folding the wrap at opposite ends of the
bale and
subsequently tying the wrap to the bale.
The present invention will be more readily apparent from the following
description of a
preferred embodiment thereof given, by way of example, with reference to the
accompanying
drawings, in which:-
Figure 1 shows a view in front elevation of a bale wrap retaining apparatus
according
to the present invention;
Figure 2 shows a plan view of the apparatus of Figure 1;
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Figure 3 shows a view in side elevation of the apparatus of Figures 1 and 2;
Figure 4 shows a broken-away view, in front elevation, all parts of the
apparatus of
Figure 1;
Figure 5 shows a side view, partly broken away, all of parts of the apparatus
of
Figures 1 through 4; and
Figure 6 shows a plan view of a pulp bale wrapping apparatus in which the
retaining
apparatus of Figures 1 through 5 can be employed.
In Figure 1 of the accompanying the drawings, there is shown a bale wrap
retaining apparatus
which comprises a bale wrap retainer device indicated generally by reference
numeral 10,
which is illustrated in gripping engagement with a bale 12 and, more
particularly, in contact
with a cover sheet forming a wrap 11 which is partially wrapped around the
bale 12.
The retainer device 10 comprises a support in the form of a transverse beam 14
which, at each
of its opposite ends 15, carries a bale wrap retainer member indicated
generally by reference
numeral 16.
Each of the retainer members 16 comprises an angle-shaped plate 18 which has
outwardly
curved edges 20 and which engages, as shown in Figure 1, in snug engagement
with an upper
side corner 22 of the bale 12 so as to retain folded side portions 24 of the
wrap 11 against
opposite sides 25 of the bale 12. Each of the angle-shaped plates 18 is
suspended from a
respective end 15 of the transverse beam 14 by a pivotal connection comprising
a swing arm
26 which it is pivotally connected at its opposite ends to the transverse beam
14 and to the
respective angle-shaped plate 18.
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The transverse beam 14 is suspended beneath an I-beam 28 by means of a
suspension in the
form of a connection indicated generally by reference numeral 30 and extends
transversely
of the I-beam 28. This connection 30 includes a pneumatically expansible and
contractible
bellows 32, which can be pneumatically inflated so as to move the transverse
beam 14
downwardly from the I-beam 28, and a pair of helical tension springs 34, which
act as return
springs for returning the transverse beam 14 upwardly towards the I-beam 28.
The bellows 32 and the springs 34 are connected to an upwardly open housing
36, which
receives the I-beam 28, and which has rollers 3 8 in rolling the engagement
with flanges of the
I-beam 28, which therefore forms a track for the movement of the connection 30
and the
retainer device 10 to and fro along the I-beam 28 above the path of travel of
the bale 12.
As can be seen from Figure 2, the transverse beam 14 is formed by a pair of
elongate parallel
plates 40, which are connected together by means of rods 42, and the swing
arms 26 axe
pivotable about the rods 42. The swing arms 26 and, thereby, the retainer
members 16 are
urged towards one another and, thus, towards of the opposite sides of the bale
12 by means
of helical tension springs 44, which are connected between the swing arms 26
and bars 46
extending between the plates 40.
The manner in which the angle-shaped plates 18 are moved into engagement with
the upper
side corners 22 of the bale 12, as the transverse beam 14 is moved downwardly
towards the
bale 12, is illustrated in Figure 4.
As shown in Figure 4, when the transverse beam 14 is in its upper position, in
which it is
illustrated in unbroken lines, the angle-shaped plate 18 hangs from the beam
14 with its two
sides 48 and 50 at an inclination to the horizontal. As the transverse beam 14
is lowered and
lower side 48 of the plate comes into contact with the bale 12, the side 50 is
pressed
downwardly onto the top of the bale 12. Upon further downward movement, both
sides of
the angle-shaped plate 18 slide on the bale 12 or, more particularly, on the
cover sheet
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wrapped around the bale 12, into the positions in which they are shown in
chain-dot lines and
in which the angle-shaped plate 18 is snugly engaged with the upper top corner
22 of the bale
12.
This movement of the angle-shaped plate 18 causes the swing arm 26 to pivot
about the
respective rod 42 in an anti-clockwise direction, as viewed in Figure 4,
against the action of
the respective spring 44.
Figure 6 shows a pulp bale wrapping apparatus or line which has a conventional
wrap
dispenser 45 at which the wrap 11 is dispensed, in known manner, onto the bale
12 and folded
against opposite sides of the bale 12 into the condition shown in Figure 1.
The wrap dispenser 45 is followed by a first tying machine 47 which is not
employed when
the present invention is in use but which may be provided as a back-up or for
occasional
special orders requiring first and second wrap retaining wires to be applied
in the
conventional manner as described above.
When the present apparatus is provided, the I-beam 28 extends from this first
tying machine
45 to an end folder 49.
With the folds of the wrap 11 held against the opposite sides of the bale 12
by the retainer
members 16 as described above, at the end of the I-beam 28 proximate the tying
machine 47,
the bale 12 is advanced along its path of travel, through to a bale spinner
51, which remains
unoperated, to the end folder 49, at which portions of the wrap 11 projecting
from opposite
ends of the wrap are folded against the opposite ends of the bale. The
retainer device 10 is
withdrawn from the bale 12 before the ends of the wrap 11 are then folded
against the bale
12.
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The retainer device 10 is driven along the I-beam by its engagement with the
bale 12. When
released from the bale 12, the retainer device is returned to its initial
position by a drive which
includes a prime mover in the form of an electric motor 52 mounted on the
housing 36, a
drive gear 54 on the shaft 55 of the motor 52 and a driven gear 56 meshing
with the drive gear
54. The driven gear 56 is coaxial with a drive wheel 58 forming a drive
member, the driven
gear 56 and the drive wheel 58 being carried on one end of an arm 60, which is
pivotable
about the motor shaft 55 against the action of a helical tension spring 62
when the drive gear
54 is rotated by the electric motor 52. This pivotation brings the drive wheel
into frictional
driving engagement with the I-beam 28 so as to propel the retainer device 10
along the I-beam
28.
The bale 12 is then advanced to a second tying machine 53, where a length of
wire (not
shown) is tied around the bale 12 to secure the wrap 11 on the bale 12.
Consequently, only
one such wire is required for that purpose.
As will be apparent to those skilled in the art, various modifications may be
made in the
above-described invention within the scope of the appended claims.
For example, the present bale wrap retaining apparatus may be employed in bale
wrapping
lines in which glue, instead of wire, is used to retain the wrap. In this
case, the present
apparatus applies sideways pressure against the wrap at the opposite sides of
the bale, while
the glue dries and while the bale is advanced from the wrap dispenser 45 to
allow a
succeeding bale to be wrapped in the wrap dispenser 45, thus reducing the time
required for
the wrapping process. Also, the present apparatus allows the use of stronger,
longer-lasting
adhesive which will maintain better bale quality without slowing production.
