The invention relates to a device for transporting tubular bag bodies, with a
longitudinal transport device with which the tubular bag bodies can be transported
essentially in the direction of their longitudinal extension, with a transverse
transport device with which the tubular bag bodies can be transported essentially
normal to their longitudinal extension, and with a transfer device for transferri5 ng
the tubular bag bodies from the longitudinal transport device to the transverse
transport device, wherein the transfer device comprises a supporting surface for
supporting the tubular bag bodies.
10 The invention also relates to a method for transporting tubular bag bodies,
wherein the tubular bag bodies are first transported essentially in the direction of
their longitudinal extension and fed to a supporting surface, wherein the tubular
bag bodies are transported away from the supporting surface essentially normal to
their longitudinal extension.
15
Such transport devices and transport methods have long been known in the prior
art and are frequently used in plants for producing bags, in particular from woven
tubes. The process usually starts from a material web, from which the tubular bag
bodies are separated into single units, in particular with a transverse cutting
20 device. The bag bodies are then transported onward in the transverse direction, in
order to gain access to the open end regions of the bag bodies in the subsequent
production steps. For this purpose, the most diverse transfer devices have been
3
proposed in the prior art, with which the change in direction during the transport
of the tubular bag bodies is brought about.
Such a device for changing the transport direction of flat tube pieces is known
from DE 10 2009 000 893 A1. The tube pieces are pushed onto a supportin5 g
surface one after the other in the longitudinal direction, in order thereafter to be
transported into the transverse direction by a transfer device. Before a tube piece
can be transported away in the transverse direction, the tube piece in this prior art
must first lie with its lateral region on the transverse transport plane in order that
10 the lateral region can be engaged by the transfer device. When the tube piece is
pushed out onto the supporting surface, therefore, it is necessary for it to be
already disposed partially in the region of the transverse transport plane, so that
the tube piece already lies on this plane shortly before its transfer. For design
reasons, the transport table in this prior art comprises interfering edges, against
15 which the bag could be pushed. The bag is thus upset, possibly even damaged,
and subsequent onward transport of the bag in an orderly manner is made
difficult. In order to prevent such collisions, DE 10 2009 000 893 A1 makes
provision in an embodiment such that the supporting surface of the transfer device
is split up into a fixed part and a height-adjustable part. The height-adjustable part
20 is constituted plate-shaped and is linked via a swivel pin to the fixed part. The
swivel pin runs in the advancing direction of the tube. With the aid of a
reciprocating piston cylinder, the height-adjustable region can be swivelled about
the swivel pin, so that the side edge of the tube piece projecting laterally beyond
4
the height-adjustable region does not run against an interfering edge of the
transverse transport plane.
Moreover, DE 10 2009 000 893 describes that a following flat workpiece can be
advanced by a certain distance in the longitudinal direction, while the precedin5 g
workpiece is transported in the transverse direction by a distance which is smaller
than the workpiece width. For this purpose, a pusher element is provided, with
which the end of the flat tube piece can be pushed into a region beneath the plane
on which the end initially lies. This region can be a free space at the side of or
10 beneath the supporting plane. The pusher element can comprise a compressed air
piston cylinder, with which a pusher finger or a pusher strip can be moved. The
pusher finger or the pusher strip then enters, in a region of the tube piece, into
contact with the latter, wherein this region does not lie on the plane. When the
pusher element is moved, the end of the tube piece thus folds down and slides
15 along on a lateral surface of the supporting element comprising the supporting
plane, until the end reaches the free space and is aligned straight again due to
restoring forces. This embodiment, however, is disadvantageously expensive in
terms of design and is not always reliable.
20 Accordingly, the problem of the present invention consists in mitigating or
eliminating the drawbacks of the prior art. In particular, the invention thus sets
itself the task of configuring the transfer of the tubular bag bodies from the
longitudinal transport device to the transverse transport device with structurally
5
straightforward means and avoiding operational failures, in such a way that the
rate of the finished bag bodies is increased.
The problem is solved by a device according to claim 1 and a method according to
claim 18. Preferred embodiments are stated in the dependent claims5 .
According to the invention, the transfer device comprises at least one upper
supporting surface and one lower supporting surface for the tubular bag bodies,
wherein a switching element is provided, which can be changed over between an
10 upper position and a lower position, wherein the tubular bag bodies in the upper
position of the switching element can be fed to the upper supporting surface and
in the lower position of the switching element to the lower supporting surface.
The tubular bag bodies are transported by means of the longitudinal transport
15 device along an, in particular, horizontal longitudinal transport plane to the
transfer device, with which the tubular bag bodies are fed to the transverse
transport device in order to perform a change of direction essentially through 90°.
The open end regions of the tubular bag bodies are thus disposed at the sides of
the transverse transport device, in order to gain access to the open end regions of
20 the bag bodies in following processing stations, for example a bottom opening
device. According to the invention, the transfer device between the longitudinal
and the transverse transport device comprises an upper supporting surface and a
lower supporting surface. The terms "upper" and "lower" relate here to the
6
operational position of the device. Accordingly, the tubular bag bodies can be
guided alternatively to the upper or to the lower supporting surface during
operation of the device by changing over the switching element. The transfer
device preferably comprises a suitable entrainment element, for example an
entrainment roller, with which the tubular bag bodies are transferred from t5 he
respective supporting surface to the transverse transport device. The tubular bag
bodies are then transported in the transverse transport direction. As a result of the
at least two supporting surfaces, delays in the passage through the transfer device
can advantageously be avoided.
10
According to the invention, successive bag bodies can be disposed overlapping
during transport over the supporting surfaces. Accordingly, the tubular bag body
can be pushed in the longitudinal transport direction onto one supporting surface,
while a preceding bag body is being transported away from the other supporting
15 surface in the transverse transport direction.
Advantageously, therefore, it is not necessary to convey the bag body completely
away from the transfer device before the next bag body arrives at the transfer
device. The number of bag bodies of the transfer device produced per unit of time
20 can thus be increased considerably. Compared with the prior art, it is
advantageous that the increase in the throughput rate at the transfer device is on
the one hand achieved with technically simple means and on the other hand the
separate supporting surfaces of the transfer device enable a reliable operation of
7
the device, wherein disruptions can for the most part be eliminated. More than
two supporting surfaces can of course also be provided. In many applications, it is
advantageous if the transfer device comprises at least one middle supporting
surface between the upper and the lower supporting surface. Plate-shaped
supporting elements are preferably provided to constitute the supporting surfaces5 .
The supporting surfaces are preferably disposed in horizontal planes. The
supporting surfaces can however also be tilted with respect to the horizontal.
With regard to a space-saving, compact embodiment, it is advantageous if the upper
10 and the lower supporting surface of the transfer device are disposed one above the
other. Essentially identical, in particular horizontal, supporting surfaces are
preferably provided. More than two supporting surfaces, for example three or four
supporting surfaces, can of course also be disposed directly above one another.
15 In order to improve the capacity of the transport device, it is advantageous if the
switching element is constituted for the alternating feed of the tubular bag bodies
to the upper and the lower supporting surface of the transfer device. Accordingly,
the tubular bag bodies are fed alternately to the upper and the lower supporting
surface of the transfer device. When more than two supporting surfaces are
20 provided, the tubular bag bodies are preferably allocated in turn to the individual
supporting surfaces of the transfer device.
8
For the swivelling of the switching element between the upper position and the
lower position, it is advantageous if the switching element is connected to a
swivel drive. The feeding of the tubular bag bodies to the upper and lower
supporting surface can be controlled by actuation of the swivel drive. The control
of the swivel drive is preferably set up to feed the tubular bag bodies alternately 5 to
the upper and the lower supporting surface.
In order to transport the tubular bag bodies to the upper and lower supporting
surface, it is advantageous if the swivel drive for swivelling the switching element
10 can be swivelled about at least one swivel axis running parallel to the transport
plane of the longitudinal transport device and extending essentially normal to the
longitudinal transport direction. Accordingly, the switching element can be tilted
upwards about the at least one, in particular horizontal, swivel axis, in order to
guide the bag body arriving at the switching element to the upper supporting
15 surface. On the other hand, the switching element can be tilted downwards in
order to guide the bag body arriving at the switching element to the lower
supporting surface.
In order to configure the transport of the tubular bag bodies along the longitudinal
20 transport device free from hindrance, it is advantageous if the switching element
comprises an upper guide element and a lower guide element, wherein a guide gap
for the passage of the tubular bag bodies is formed between the upper guide
element and the lower guide element. Accordingly, the tubular bag bodies are
9
conveyed through the guide gap of the switching element, wherein the tubular bag
bodies are guided, depending on the position of the switching element, to the
upper supporting surface or to the lower supporting surface.
An embodiment is particularly preferable wherein the upper guide elemen5 t
comprises at least one upper finger element, preferably a plurality of upper finger
elements spaced apart normal to the longitudinal transport direction, and/or the
lower guide element comprises at least one lower finger element, preferably a
plurality of lower finger elements spaced apart normal to the longitudinal transport
10 direction. In the case of a plurality of finger elements, it is advantageous if the upper
finger elements and/or the lower finger elements can be switched together, in
particular swivelled together, between the upper position and the lower position.
According to an alternative embodiment, a plate element, in particular a guide
15 plate, is provided as an upper and/or lower guide element, said plate element
being able to be adjusted between the upper or lower position for transporting the
tubular bag bodies in the direction of the upper or lower supporting surface.
In order to change over the switching element for allocating the tubular bag
20 bodies to the upper or the lower supporting surface, it is advantageous if the upper
guide element, in particular the upper finger elements, are mounted on an upper
shaft element and/or the lower guide element, in particular the lower finger
elements, are mounted on a lower shaft element. The shaft element is preferably
10
coupled to the swivel drive, in order to enable the change-over of the switching
element between the upper and the lower position.
In order to transport the tubular bag bodies continuously and with a high degree of
reliability to the respective supporting surface of the transfer device, it i5 s
advantageous if an upper conveying surface ascending in the longitudinal
transport direction is provided between the switching element and the upper
supporting surface and/or that a lower conveying surface descending in the
longitudinal transport direction is provided between the switching element and the
10 lower supporting surface. An essentially horizontal longitudinal transport plane is
preferably provided, which is followed by the conveying surfaces to the
supporting surfaces of the transfer device. The switching element is preferably
disposed in the transition region between the longitudinal transport plane and the
conveying surfaces.
15
For this purpose, it is advantageous if the upper conveying surface and/or the
lower conveying surface are disposed at an obtuse angle to the longitudinal
transport plane of the longitudinal transport device. The tubular bag bodies can
thus be guided, depending on the position of the switching element, obliquely
20 upwards to the upper supporting surface or obliquely downwards to the lower
supporting surface of the transfer device. The longitudinal transport plane is
disposed in the vertical direction preferably essentially in the middle between the
upper supporting surface and the lower supporting surface of the transfer device.
11
In order to enable the allocation of the film sequence during the transition from the
longitudinal transport plane to the conveying surfaces, there is provided according
to a structurally simple embodiment a wedge element for forming front sections of
the upper and lower conveying surface between the switching element and the
transfer device, wherein the wedge element can preferably be displaced, 5 in
particular swivelled, between an upper position corresponding to the lower position
of the switching element and a lower position corresponding to an upper position of
the switching element. The wedge element is thus preferably disposed in the lower
position when the switching element is disposed in the upper position, and vice
10 versa. Advantageously, the guide path to the upper or lower supporting surface of
the transfer device is thus reliably cleared. In this preferred embodiment, it is
possible in particular to prevent the bag bodies from colliding with the wedge tip of
the wedge element. The switching element preferably comprises the previously
described guide elements, with which the bag bodies are conveyed in particular
15 alternately in the direction of the upper or lower supporting surface, wherein the
wedge element is switched between the lower and upper position.
The feeding of the tubular bag bodies to the respective supporting surface of the
transfer device is facilitated if an upper conveyor drive, in particular with at least
20 one conveyor belt, is provided for transporting the tubular bag bodies on the upper
conveying surface between the switching element and the upper supporting
surface and/or a lower conveyor drive, in particular with at least one further
conveyor belt, is provided for transporting the tubular bag bodies on the lower
12
conveying surface between the switching element and the lower supporting
surface of the transfer device.
According to a particularly preferred embodiment, the transfer device comprises a
hold-down element in each case for the upper and/or lower supporting surface5 ,
said hold-down element being able to be adjusted between a release position and a
clamping position. By means of the hold-down element for the temporary
clamping of the bag body on the upper or lower supporting surface, it is possible
reliably to prevent the bag body from rising during the transition from the
10 longitudinal transport device onto the transfer device. The bag body is laid down
in a controlled manner on the upper or lower supporting surface by means of the
hold-down element. Furthermore, unintended opening of the tube section by an
oncoming air flow can largely be prevented. When the transfer or discharge
position for the transverse transport is reached, the hold-down element can be
15 raised from the clamping position clamping the bag body on the upper or lower
supporting surface into the release position releasing the bag body.
In order to prevent an abrupt retardation of the bag body upon entry into the
transfer device, it is advantageous if the holddown element comprises a hold20
down part which is mobile in the longitudinal transport direction and which is
preferably constituted by a belt, in particular an endless belt circulating around
two deflection rollers. Accordingly, the hold-down part is mobile together with
the bag body in the longitudinal transport direction, until the bag body reaches the
13
discharge position from which the transverse transport of the bag body is initiated.
In this way, sliding friction between the hold-down element and the bag body is
preferably prevented, when the bag body is guided into the discharge position on
the upper or lower supporting surface.
5
The hold-down element is preferably connected to a lift element, which can be
swivelled about a swivel shaft in order to move the hold-down element between
the release and the clamping position. By swivelling the lift element about the
swivel shaft, the holddown element is transferred from the lower clamping
10 position into the raised release position and vice versa.
In order to raise the hold-down element from the bag body before the start of the
transverse transport, it is advantageous if the lift element comprises at least one
lifting arm, which is mounted on a bearing element, in particular a cam, which is
15 fitted to a further swivel shaft. The cam has in a known manner an out-of-round or
oval shape, in order to dispose the lifting arm, depending on the angular position
of the cam, in the lowered clamping position or in the raised release position.
For the transfer of the hold-down element between the release position and the
20 clamping position, it is advantageous if a linear drive element, in particular an
electrically, pneumatically or hydraulically actuated cylinder-piston drive, is
connected via a reversing lever to the further swivel shaft. By actuation of the
linear drive element, the further swivel shaft is swivelled via the reversing lever
14
attached thereto. The effect of the swivelling motion of the further swivel shaft is
that the cam sitting thereon raises the lifting arm, as a result of which the holddown
element is raised into the release position.
In order to couple the position of the hold-down element with the transvers5 e
transport device, it is advantageous if the further swivel shaft is connected via a
swivelling lever to a contact roller, which can be swivelled between an inactive
position releasing the bag body and an active position leading the bag body away
into the transverse transport direction. In this embodiment, the contact roller is
10 disposed in the active position for the transverse transport when the hold-down
element is disposed in the release position and vice versa. The transport out of the
transfer device can thus be coordinated with the hold-down element.
In order to bring about the transverse transport of the bag body, it is advantageous
15 if the contact roller in the active position is lowered onto a drive roller, which is
connected to a drive. Due to the fictional engagement between the contact roller,
the bag body and the drive roller, the bag body is transported out of the transfer
device in the transverse transport direction.
20 For transporting the tubular bag body away from the transfer device, it is
advantageous if the upper supporting surface and the lower supporting surface of
the transfer device are connected via an upper and a lower merging section to a
common transverse transport plane of the transverse transport device.
15
Accordingly, the tubular bag bodies are guided from the supporting surfaces of
the transfer device into the, in particular, horizontal transport plane of the
transverse transport device. The tubular bag bodies are preferably conveyed
alternately from the upper and the lower supporting surface along the merging
sections to the common transverse transport plane of the transverse transpor5 t
device. Further conveyor drives, in particular with conveyor belts, are preferably
provided for transporting the tubular bag bodies on the merging sections.
Corresponding to the conveying sections, the merging sections can be constituted
between the switching element and the transfer device. A horizontal transverse
10 transport plane is preferably provided, which preferably essentially coincides with
the common longitudinal transport plane.
In this embodiment, moreover, it is advantageous if the upper merging section
and/or the lower merging section are in each case disposed at an obtuse angle to
15 the transport plane of the transverse transport device. Accordingly, the upper
merging section leads obliquely downwards, while the lower merging section
leads obliquely upwards. The common transverse transport plane of the transverse
transport device is disposed in the vertical direction, preferably essentially in the
middle between the upper supporting surface and the lower supporting surface of
20 the transfer device.
As is usual with bag production plants in themselves, it is advantageous if a
separating device is provided for separating the tubular bag bodies into single
16
units. With the aid of the separating device, a tubular material web can be split up
into single tubular bag bodies, i.e. constituting open end regions.
The separating device is preferably disposed in the region of the longitudinal
transport device. The material web and – after its separation into single units - t5 he
tubular bag bodies are transported in the flat state, i.e. with bag sections lying one
upon the other, through the longitudinal transport device.
A transverse cutting device for severing a tubular material web transverse to the
10 longitudinal transport direction is preferably provided as a separating device. Such
transverse cutting devices are known per se in the prior art. For example, a
rotating blade roller can be provided, with which the material web is severed
transverse to the longitudinal transport direction.
15 As is also usual with bag production plants, an opening device is preferably
provided for forming a bottom opening between bag sections at the open end
region of the tubular bag body. The opening device is preferably disposed in the
region of the transverse transport device. The bag bodies arriving in the flat state
are thereby opened in the bottom region, before the bag bottom is formed in a
20 bottoming station, also known in the prior art.
The method according to the invention is characterised in that the tubular bag
bodies are fed by changing over a switching element to an upper supporting
17
surface and a lower supporting surface, from which the tubular bag bodies are
transported away in the transverse transport direction essentially normal to their
longitudinal extension.
The advantages and technical effects of this method emerge from the precedi5 ng
comments in respect of the transport device according to the invention.
An embodiment is particularly advantageous wherein the tubular bag bodies are
fed alternately to the upper supporting surface and the lower supporting surface.
10 The throughput of the tubular bag bodies through the transfer device can thus be
increased considerably.
The invention is explained in greater detail below with the aid of a preferred
example of embodiment, to which however it is not limited. In the drawing:
15 Fig. 1 and 2 show diagrammatic cross-sectional views of a device according to the
invention for transporting tubular bag bodies, which are first transported in the
direction of their longitudinal extension, are then fed alternately to an upper
supporting surface (see fig. 1) or to a lower supporting surface (see fig. 2) and are
finally transported away in the direction normal to their longitudinal extension;
20 Fig. 3, 4 each show schematically a diagrammatic view of the device according to
fig. 1, 2, wherein the tubular bag body is fed to the upper supporting surface;
18
Fig. 5 shows a diagrammatic view of a further device according to the invention,
wherein an alternative embodiment of the transverse transport device is provided;
and
Fig. 6 and 7 each show a further view of the device according to fig. 5.
5
A device 1 for transporting tubular bag bodies 2 is shown in the fig. Device 1
comprises a longitudinal transport device 3, with which a tubular material web, in
particular a woven tube (not shown) is transported in the flat state along a
horizontal transport plane in longitudinal transport direction 3', i.e. in the direction
10 of its longitudinal extension. The material web forms a succession of bag bodies
2, which, as explained in greater detail below, are thereafter separated into single
units. Longitudinal transport device 3 comprises a longitudinal drive, in particular
in the form of tensioning or conveying rollers, which are known in the prior art
and do not therefore require a more detailed explanation. Moreover, a separating
15 device 5 is assigned to longitudinal transport device 3, by means of which
separating device the tubular bag bodies 2 are formed from the material web. In
the embodiment shown, a transverse cutting device for severing the tubular
material web normal to longitudinal transport direction 3' is provided as
separating device 5, which transverse cutting device comprises an upper roller
20 element 6 with a blade element and a lower roller element 7 with a corresponding
receiving opening. Roller elements 6, 7 are mounted so as to be rotatable in
opposite directions, so that with each rotation the material web is severed once
normal to the longitudinal extension in order to separate bag bodies 2 into single
19
units. A tensioning roller 4 is provided for tensioning the material web in the
transverse cutting device. Tubular bag bodies 2 comprise two bag sections lying
one upon the other, wherein each bag section can be constituted by a plurality of
layers of different material.
5
Tubular bag bodies 2 are then transported in the flat state in longitudinal transport
direction 3', wherein the open end regions of tubular bag bodies 2 are disposed at
the front or rear end.
10 As can be seen from fig. 3, 4, device 1 also comprises a transverse transport
device 8, with which tubular bag bodies 2 are transported in transverse transport
direction 8', i.e. essentially normal to their longitudinal extension, in order to be
fed to a bottom opening device (not shown) for forming a bottom opening at the
open end region of tubular bag bodies 2. Moreover, a transfer device 9 is provided
15 for transferring tubular bag bodies 2 from longitudinal transport device 3 (shown
only diagrammatically in fig. 3, 4) to transverse transport device 8.
As can further be seen from fig. 3, 4, transfer device 9 comprises an upper
supporting surface 10 and a lower supporting surface 11 for tubular bag bodies 2.
20 Advantageously, delays in the transport of the tubular bag bodies through transfer
device 9 can thus for the most part be avoided. A tubular bag body 2 can thus
already be pushed onto the one supporting surface 10, 11, while preceding bag
body 2 has still not left the other supporting surface 10 or 11. In the embodiment
20
shown, upper 10 and a lower support surface 11 of transfer device 9 are disposed
in horizontal planes one above the other. Support surfaces 10, 11 are provided at
the upper sides of plate-shaped support elements. It is of course also possible for
more than two supporting surfaces 10, 11 to be provided.
5
In order to feed tubular bag bodies 2 alternately to upper supporting surface 10
and lower supporting surface 11, a switching element 12 is provided, which can
be changed over between an upper position (see fig. 1) and a lower position (see
fig. 2). In the upper position of switching element 12 according to fig. 1, tubular
10 bag bodies 2 are fed to upper supporting surface 10, and in the lower position of
switching element 12 according to fig. 2 to lower supporting surface 11.
According to fig. 1, 2, a plurality of bag bodies 2 are guided one after another to
upper 10 and lower support surface 11. Preferably, however, provision is made
such that tubular bag bodies 2 are fed alternately to upper 10 and lower supporting
15 surface 11. The number of finished bag bodies 2 can thus be significantly
increased.
As can be seen from fig. 1, 2, switching element 12 is connected to a swivel drive
13, with which switching element 12 can be swivelled about a swivel axis running
20 in the longitudinal transport plane of longitudinal transport device 3 and extending
essentially normal to longitudinal transport direction 3'. In the embodiment
shown, switching element 12 comprises an upper guide element 14 and a lower
guide element 15. A guide gap 16 is formed between upper guide element 14 and
21
lower guide element 15, said guide gap enabling a passage of tubular bag bodies 2
in longitudinal transport direction 3'. Upper guide element 14 comprises at least
one upper finger element 14'. Correspondingly, lower guide element 15 comprises
at least one lower finger element 15'. Advantageously, a plurality of upper finger
elements 14' spaced apart normal to longitudinal transport direction 3' and 5 d a
plurality of lower finger elements 15' spaced apart normal to longitudinal
transport direction 3' are provided, which can be swivelled together between the
upper position according to fig. 1 and the lower position according to fig. 2. For
this purpose, upper guide element 14 is mounted on an upper shaft element 17 and
10 lower guide element 15 on a lower shaft element 18, which comprise swivel axes
running parallel to the longitudinal transport plane of longitudinal transport device
3 for the purpose of changing over switching element 12.
In the embodiment shown, the swivel axes of upper 14' and lower finger element
15 15' are disposed, viewed in longitudinal transport direction 3', on the front end
regions of upper and lower guide element 15. However, the swivel axes of upper
14' and lower finger elements 15' can of course also be disposed in such a way
that bag bodies 2 first meet, in longitudinal transport direction 3', the free ends of
upper 14' and lower finger elements 15'.
20
As can further be seen from fig. 1, 2, an upper conveying surface 19 ascending in
longitudinal transport direction 3' is provided between switching element 12 and
upper supporting surface 10. Correspondingly, a lower conveying surface 20
22
descending in longitudinal transport direction 3' is provided between switching
element 12 and lower supporting surface 11. Upper conveying surface 19 and
lower conveying surface 20 are each disposed at an obtuse angle to the
longitudinal transport plane of longitudinal transport device 3', which runs
horizontally in the embodiment shown. In the embodiment shown, a wedg5 e
element 21 is provided for the formation of the front sections of upper 19 and
lower conveying surface 20 between switching element 12 and transfer device 9.
For the transport of tubular bag bodies 2 on upper conveying surface 19 between
switching element 12 and upper supporting surface 10, an upper conveyor drive
10 22 is provided, which comprises a conveyor belt 23 on both sides of upper
conveying surface 19. Moreover, a lower conveyor drive 24 is provided for
transporting tubular bag bodies 2 on lower conveying surface 20 between
switching element 12 and lower supporting surface 11 of transfer device 9. Lower
conveyor drive 24 is constituted, corresponding to upper conveyor drive 22, with
15 further conveyor belts 25 on both sides of lower conveying surface 20.
Corresponding conveying means can be assigned to supporting surfaces 10, 11 in
order to dispose the tubular bag bodies in a discharge position lying completely on
supporting surfaces 10, 11.
20 By periodic changing-over of switching element 12, tubular bag bodies 2 are
allocated alternately to upper supporting surface 10 and lower supporting surface
11 of transfer device 9.
23
In the embodiment shown, woven tubes are transported, which on account of the
base material, for example polypropylene fabric, are not dimensionally stable and
therefore exhibit only a small transverse rigidity. For this reason, it is
advantageous if the tube sections are guided both from below and from above
over essentially the entire transport length of longitudinal transport device 3 int5 o
transverse transport device 8. Accordingly, unguided sections should be as short
as possible at the transfer points.
During the conveying of the tube sections in longitudinal transport direction 3
10 normal to the cross-sectional area of the tube sections, there is the risk of
unintended opening due to the oncoming ambient air flow on account of the
required high transport speed. In the embodiment shown, therefore, provision is
made such that the front end of the bag section is held securely in the closed
position over the entire width. This is brought about by upper finger elements 14'
15 and lower finger elements 15' in the region of the transfer to upper conveying
surface 19 and lower conveying surface 20. In the embodiment shown, end
regions of finger elements 14', 15' are disposed at ascending upper conveying
surface 19 and at descending lower conveying surface 20. In this way, upper
finger elements 14' and lower finger elements 15' assume a guide function only
20 until such time as the front end of the tube section arrives on upper conveying
surface 19 and respectively on lower conveying surface 20. Constituted along
upper 19 and lower conveying surface 20 is a gap-shaped guide channel, with
which bag body 2 is guided at the upper and lower side. The allocation of bag
24
bodies 2 is achieved by the interaction of guide elements 14, 15 with guide wedge
21, in that guide wedge 21 defines a gap-shaped conveying channel and guide
elements 14, 15 bring about guidance in the conveying direction by a brief control
over the entire width. In this way, bag bodies 2 are reliably allocated, without
jamming-up occurring, in the direction of upper supporting surface 10 or lowe5 r
supporting surface 11.
As can be seen from fig. 3, 4, upper supporting surface 10 and lower supporting
surface 11 of transfer device 9 are connected via an upper merging section 26 and
10 a lower merging section 27 to a common, horizontal transverse transport plane of
transverse transport device 8, which leads to the opening device (not shown) for
forming a bottom opening between bag sections at the open end region of the
tubular bag bodies. Upper merging section 26 and lower merging section 27 are
constituted, corresponding to upper conveying surface 19 and lower conveying
15 surface 20, between switching element 12 and transfer device 9. Accordingly,
merging sections 26, 27 are each disposed at an obtuse angle to the transverse
transport plane of transverse transport device 8, in order to guide tubular bag
bodies 2 alternately from upper supporting surface 10 obliquely downwards and
from lower supporting surface 11 obliquely upwards to the common transverse
20 transport plane of transverse transport device 8.
As can be seen from fig. 3, 4, transfer device 9 comprises, for each supporting
surface 10, 11, a entrainment element 28 (shown only diagrammatically) in the
25
form of entrainment rollers, with which tubular bag bodies 2 are entrained from
respective support surface 10, 11 into associated merging section 26, 27.
Moreover, transfer device 9 comprises, for each supporting surface 10, 11, a holddown
element 29, which can be adjusted between a release position and a
clamping position for the temporary clamping of tubular bag bodies 5 2.
In fig. 5 to 7, device 1 is represented with an alternative embodiment of holddown
element 29 for upper 10 and lower supporting surface 11. Hold-down
elements 29 at upper 10 and lower supporting surface 11 are constituted
10 essentially identical, so that the explanations relate in like manner to both holddown
elements 29. In the embodiment according to fig. 5 to 7, hold-down element
29 comprises a hold-down part 30 mobile in the longitudinal transport direction 3',
which in the embodiment shown is constituted by an endless belt 32 circulating
around two deflection rollers 31. Endless belt 32 is entrained by incoming bag
15 body 2, while endless belt 32 is disposed in the clamping position. As with the
preceding embodiment, hold-down element 29 can be adjusted between a release
position (see fig. 5, 6) and a clamping position (not shown) for the temporary
pressing of bag body 2 against upper supporting surface 10 or against lower
supporting surface 11.
20
For this purpose, hold-down element 29 is connected to a lift element 33, which
can be swivelled about a swivel shaft 34 in order to move hold-down element 29
up and down between the release position and the clamping position. In the
26
embodiment shown, lift element 33 comprises two lifting arms 35, which are
connected non-rotatably to swivel shaft 34. The free ends of lifting arms 35 are
mounted on cams 36, which are fitted to a further swivel shaft 37. For the
actuation of hold-down element 29, a linear drive element 38 is provided, which
in the embodiment shown is constituted by an, in particular, pneumatically o5 r
hydraulically actuated cylinder-piston drive. Linear drive element 38 is connected
via a reversing lever 39 to further swivel shaft 37. In the extended state of linear
drive element 38, hold-down element 29 is disposed via cam 36 and lifting arms
35 in the raised release position, in which bag body 2 can be transported away
10 from upper 10 or lower supporting surface 11 in the transverse transport direction.
As can further be seen from fig. 5, 6, further swivel shaft 37 is connected via a
swivelling lever 40 to a passive or driveless contact roller 41, which can be adjusted
between an inactive position for positioning bag body 2 on upper 10 or lower
15 supporting surface 11 and an active position for transporting bag body 2 away into
upper 26 or lower merging section 27. In the shown active position, contact roller
41 is lowered onto a drive roller 43, which is connected to a drive 42.
Accordingly, the transfer of bag body 2 from longitudinal transport device 3 into
transverse transport device 8 can be brought about by means of transfer device 9
20 as follows.
Tubular bag bodies 2 are conveyed in longitudinal transport direction 3' onto
upper 10 or lower supporting surface 11 of transfer device 9, wherein linear drive
27
element 38 is disposed in the retracted state, in order on the one hand to dispose
hold-down element 29 in the form of endless belt 32 in the lowered clamping
position and on the other hand to dispose contact roller 41 in the inactive position
raised from drive roller 43. Bag body 3 is then stopped at a defined position, to
which a light barrier (not shown) is preferably assigne5 d.
In order to initiate the transporting-away of bag body 2 in the transverse transport
direction, linear drive element 38 is transferred into the extended state in order to
swivel further swivel shaft 37. The swivelling motion of further swivel shaft 37 is
10 on the one hand transmitted via swivelling lever 41 to contact roller 41, so that
bag body 2 is clamped between contact roller 41 and drive roller 43. On the other
hand, the effect of the swivelling of further swivel shaft 37 is that lifting arms 35
are pushed upwards via cam 36, as a result of which hold-down element 29 is
raised from bag body 2. The effect of this is that bag body 2 is conveyed between
15 contact roller 41 and drive roller 43 into upper 26 or lower merging section 27.
28
We Claim:
1. A device (1) for transporting tubular bag bodies (2), with a longitudinal
transport device (3) with which the tubular bag bodies (2) can be
transported essentially in the direction (3') of their longitudinal extension,
with a transverse transport device (8) with which the tubular bag bodie5 s
(2) can be transported essentially normal to their longitudinal extension,
and with a transfer device (9) for transferring the tubular bag bodies (2)
from the longitudinal transport device (3) to the transverse transport device
(8), wherein the transfer device (9) comprises a supporting surface for
10 supporting the tubular bag bodies (2), characterised in that the transfer
device (9) comprises at least one upper supporting surface (10) and one
lower supporting surface (11) for the tubular bag bodies (2), wherein a
switching element (12) is provided, which can be changed over between
an upper position and a lower position, wherein the tubular bag bodies (2)
15 in the upper position of the switching element (12) can be fed to the upper
supporting surface (10) and in the lower position of the switching element
(12) to the lower supporting surface (11), wherein the switching element
(12) comprises an upper guide element (14) and a lower guide element
(15), wherein a guide gap (16) for the passage of the tubular bag bodies (2)
20 is formed between the upper guide element (14) and the lower guide
element (15).
2. The device (1) according to claim 1, characterised in that the upper (10)
and the lower supporting surface (11) of the transfer device (9) are
29
disposed one above the other.
3. The device (1) according to claim 1 or 2, characterised in that the
switching element (12) is constituted for the alternating feed of the tubular
bag bodies (2) to the upper (10) and the lower supporting surface (11) of
the transfer device (5 9).
4. The device according to any one of claims 1 to 3, characterised in that the
switching element (12) is connected to a swivel drive (13) for swivelling
the switching element (12) between the upper position and the lower
position, wherein preferably the swivel drive (13) for swivelling the
10 switching element (12) can be swivelled about at least one swivel axis
running parallel to the transport plane of the longitudinal transport device
(8) and extending essentially normal to the longitudinal transport direction
(3').
5. The device (1) according to any one of claims 1 to 4, characterised in that
15 the upper guide element (14) comprises at least one upper finger element
(14'), preferably a plurality of upper finger elements (14') spaced apart
normal to the longitudinal transport direction (3') and/or the lower guide
element (15) comprises at least one lower finger element (15'), preferably
a plurality of lower finger elements (15') spaced apart normal to the
20 longitudinal transport direction (3'), wherein preferably the upper guide
element (14), in particular the upper finger elements (14'), are mounted on
an upper shaft element (17) and/or the lower guide element (15), in
particular the lower finger elements (15'), are mounted on a lower shaft
30
element (18).
6. The device (1) according to any one of claims 1 to 5, characterised in that
an upper conveying surface (19) ascending in the longitudinal transport
direction (3') is provided between the switching element (12) and the
upper supporting surface (10) and/or that a lower conveying surface (5 20)
descending in the longitudinal transport direction (3') is provided between
the switching element (12) and the lower supporting surface (11), wherein
the upper conveying surface (19) and/or the lower conveying surface (20)
preferably are disposed at an obtuse angle to the longitudinal transport
10 plane of the longitudinal transport device (3).
7. The device (1) according to claim 6, characterised in that a wedge element
(21) for forming front sections of the upper (19) and lower conveying
surface (20) is provided between the switching element (12) and the
transfer device (9), wherein the wedge element (21) can preferably be
15 displaced, in particular swivelled, between an upper position
corresponding to the lower position of the switching element (12) and a
lower position corresponding to an upper position of the switching element
(12).
8. The device (1) according to claim 6 or 7, characterised in that an upper
20 conveyor drive (22), in particular with at least one conveyor belt (23), is
provided for transporting the tubular bag bodies (2) on the upper
conveying surface (19) between the switching element (12) and the upper
supporting surface (10) and/or a lower conveyor drive (24), in particular
31
with at least one further conveyor belt (25), is provided for transporting
the tubular bag bodies (2) on the lower conveying surface (20) between the
switching element (12) and the lower supporting surface (11) of the
transfer device (9).
9. The device (1) according to any one of claims 1 to 8, characterised in tha5 t
the transfer device (9) comprises a hold-down element (29) in each case
for the upper (10) and/or lower supporting surface (11), said hold-down
element being able to be adjusted between a release position and a
clamping position, wherein preferably the hold-down element (29)
10 comprises a hold-down part (30) which is mobile in the longitudinal
transport direction (3') and which is preferably constituted by a belt, in
particular an endless belt (32) circulating around two deflection rollers
(31).
10. The device (1) according to claim 9, characterised in that the hold-down
15 element (29) is connected to a lift element (33), which can be swivelled
about a swivel shaft (34) in order to move the hold-down element (29)
between the release position and the clamping position, wherein preferably
the lift element (33) comprises at least one lifting arm (35), which is
mounted on a bearing element, in particular a cam (36), which is fitted to a
20 further swivel shaft (37), wherein preferably a linear drive element (38), in
particular an electrically, pneumatically or hydraulically actuated cylinderpiston
drive, is connected via a reversing lever (39) to the further swivel
shaft (37), wherein preferably the further swivel shaft (37) is connected via
32
a swivelling lever (40) to a contact roller (41), which can be swivelled
between an inactive position releasing the bag body (2) and an active
position leading the bag body (2) away into the transverse transport
direction (8'), wherein preferably the contact roller (41) in the active
position is lowered onto a drive roller (43), which is connected to a driv5 e
(42).
11. The device (1) according to any one of claims 1 to 10, characterised in that
the upper supporting surface (10) and the lower supporting surface (11) of
the transfer device (9) are connected via an upper (26) and a lower
10 merging section (27) to a common transverse transport plane of the
transverse transport device (8), wherein the upper merging section (26)
and/or the lower merging section (27) are in each case preferably disposed
at an obtuse angle to the transport plane of the transverse transport device
(8).
15 12. The device (1) according to any one of claims 1 to 11, characterised in that
a separating device (5) is provided for separating the tubular bag bodies
(2) into single units, wherein a transverse cutting device for severing a
tubular material web transverse to the longitudinal transport direction (3')
is preferably provided as a separating device (5).
20 13. The device (1) according to any one of claims 1 to 12, characterised in that
an opening device is provided for forming a bottom opening between bag
sections at the open end region of the tubular bag bodies (2).
33
14. A method for transporting tubular bag bodies (2), wherein the tubular bag
bodies (2) are first transported essentially in the direction of their
longitudinal extension and fed to a supporting surface, wherein the tubular
bag bodies (2) are transported away from the supporting surface
essentially normal to their longitudinal extension, characterised in that th5 e
tubular bag bodies (2) are fed by changing over a switching element (12)
to an upper supporting surface (10) and a lower supporting surface (11),
wherein the switching element (12) comprises an upper guide element (14)
and a lower guide element (15), wherein the tubular bag bodies (2) pass
10 through a guide gap (16) which is formed between the upper guide
element (14) and the lower guide element (15), wherein the tubular bag
bodies (2) are transported away from the upper (10) and the lower
supporting surface (11) in the transverse transport direction (8') essentially
normal to their longitudinal extension.
15 15. The method according to claim 14, characterised in that the tubular bag
bodies (2) are fed alternately to the upper supporting surface (10) and the
lower supporting surface (11).