[0001] The present invention relates to a bagging machine comprising a constraint device
for auxiliary elements near to forming tube of an automatic bagging machine of the
type specified in the preamble of the first claim.
[0002] Automatic bagging machines are currently known which are capable of receiving a sheet
of material unwound from a reel, for wrapping said sheet around a forming tube and
for sealing said sheet with the product to be bagged inside.
[0003] Said machines, precisely in the phase of forming and welding the sheet around the
forming tube, are often equipped with auxiliary elements, positioned adjacent to said
forming tube, suitable for conveying said sheet in an appropriate manner around said
forming tube and/or cooperating in the operations of welding.
[0004] The known technique provides, in particular in the case of rectangular packages,
auxiliary, adjustable and movable elements, this because they must be calibrated in
an extremely precise manner according to the thickness of the sheet, or in the case
of jams or maintenance because they must be separated from the forming tube.
[0005] The auxiliary elements are connected screwed to a support flange of the forming tube
and can be moved through slots, obtained in said flange, which allow to adjust their
position for the aforementioned actions.
[0006] The known art described includes some important drawbacks.
[0007] In particular, the displacement of the auxiliary elements, which is an operation
that can also take place several times in a day, involves downtime and therefore the
time required for restoration affects the productivity of the line.
[0008] In addition, the unscrewing and re-screwing of said auxiliary elements on said flange
requires tools such as Allen screws, feeler gauges and more, not always available
to production workers with the need for intervention by personnel in charge of maintenance,
with a further increase in terms of time and inefficiencies. Furthermore, the restoration
and calibration of the position of said auxiliary elements are complex precision operations
which require time and expertise. Finally, the slots on the flange are not precise
guides and often induce fixing inaccuracies which further complicate the realignment
with the forming tube.
[0009] In this situation, the technical task underlying the present invention is to devise
a bagging machine comprising a constraint device for auxiliary elements near to forming
tube capable of substantially obviating at least part of the aforementioned drawbacks.
[0010] Within the scope of said technical task, an important object of the invention is
to devise a bagging machine capable of allowing the adjustment of the auxiliary elements
without completely or partially disconnecting said auxiliary elements from said device.
[0011] Another important object of the present invention is to obtain a bagging machine
that does not require instrumentation and/or specialized personnel for adjustment.
Finally, another important object of the invention is to make a bagging machine designed
to reduce machine downtime.
[0012] The technical task and the specified aims are achieved by a constraint device for
auxiliary elements near to forming tube as claimed in the annexed claim 1. Preferred
technical solutions are highlighted in the dependent claims.
[0013] The characteristics and advantages of the invention are clarified below by the detailed
description of preferred embodiments of the invention, with reference to the accompanying
figures, in which:
the Fig. 1 shows a side view of the bagging machine according to the present invention;
the Fig. 2 shows a perspective view of a portion of the bagging machine according to the present
invention including a forming tube, illustrating an embodiment of the adjustment means
of the position of auxiliary elements;
the Fig. 3 illustrates, in an axonometric view, a track and a locking system and rapid unlocking
of the auxiliary elements according to one embodiment of the device according to the
present invention; and
the Fig. 4 illustrates, in top view, a particular of Fig. 3.
[0014] In the present document, the measurements, values, shapes and geometric references
(such as perpendicularity and parallelism), when associated with words like "about"
or other similar terms such as "approximately" or "substantially", are to be considered
as except for measurement errors or inaccuracies due to production and/or manufacturing
errors, and, above all, except for a slight divergence from the value, measurements,
shape, or geometric reference with which it is associated. For instance, these terms,
if associated with a value, preferably indicate a divergence of not more than 10%
of the value.
[0015] Moreover, when used, terms such as "first", "second", "higher", "lower", "main" and
"secondary" do not necessarily identify an order, a priority of relationship or a
relative position, but can simply be used to clearly distinguish between their different
components.
[0016] The measurements and data reported in this text are to be considered, unless otherwise
indicated, as performed in the International Standard Atmosphere ICAO (ISO 2533:1975).
[0017] With reference to the Figures, the bagging machine according to the invention is
globally indicated with the number
1.
[0018] The bagging machine 1 is capable of making containment bags starting from a flat
sheet, containment bags. Such machines are known as packaging machines, bagging or
vertical packaging machines.
[0019] Said bagging machine 1 is known per se, apart from the details described below, and
is suitable for making containment bags starting from flat sheets of preferably polymeric
material generally wound in rolls. The said bags are made by rolling the sheets in
the longitudinal direction, the welding, preferably thermal, in the longitudinal direction
to form a closed tube, the double welding and cutting, in the transverse direction,
of the said tube, to make the closed container. Said bagging machine 1 or packaging
machine also allows the container to be filled during its formation.
[0020] Similar machines are described for example in patent application
EP 2 607 243 A1. The bagging machine 1 comprises, briefly, a forming tube
3, around which said sheet is arranged during longitudinal sealing, at least one auxiliary
element
2 of the sheet on said forming tube 3, a constraint device 5 of the auxiliary elements
2 to the bagging machine 1.
[0021] The constraint device 5 is therefore functionally and mechanically connected to the
auxiliary elements 2. The auxiliary elements 2 are positioned in proximity to the
forming tube 3 of the bagging machine 1 and are able to orient the sheet 2, or to
cooperate in welding operations (in this case they are also called auxiliary welding
elements) or to perform other known operations.
[0022] The device 5 is capable of allowing the adjustment by a user, or rather by a production
worker, of the position of the auxiliary elements 2 around the forming tube 3.
[0023] The forming tube 3 is a tube, generally with a normal circular section, around which
the sheet is arranged during its longitudinal welding and preferably partly during
its transverse sealing and filling.
[0024] The shape of said auxiliary elements 2 is substantially prismatic, with a face adjacent
to the forming tube 3, said adjacent face adapted to help positioning and maintaining
the work sheet in position, acting as a guide during the movement of said work sheet
around to said forming tube 3. They are also preferably able to form a prismatic-shaped
package with a rectangular base, preferably comprising a welding on one of the four
corners which unwind in the longitudinal direction. The face of the auxiliary element
2 adjacent to the forming tube 3 is therefore a shaped face adapted to reproduce the
shape or at least a section of the shape of the forming tube 3, for example a flat
face for one side of a square forming tube or a defining face an arc of circumference
for a circular forming tube and so on. The distance between the face of the auxiliary
element 2 adjacent to the forming tube 3 and the forming tube 3 is preferably between
1 mm and 5 mm.
[0025] Preferably, the device 5 comprises a flange
4 transversal to the working direction of said forming tube 3 and constrained to the
machine 1 near the tube 3.
[0026] The flange 4 is supported, not in contact with the forming tube 3, by a random support
structure.
[0027] Preferably, the flange 4 is provided with a plurality of tracks
41 lying on said flange 4.
[0028] Said tracks 41 can extend beyond the flange 4, and be connected integrally with or
formed in said flange 4.
[0029] The tracks 41 are therefore arranged substantially radial with respect to the substantially
vertical axis defined by the forming tube 4.
[0030] Again, preferably according to the present invention, the tracks 41 can be connected
with freedom of movement to the auxiliary elements 2.
[0031] The tracks 41 are therefore able to allow, by providing a directional guide, at least
the displacement of the auxiliary elements 2 in a radial direction with respect to
the forming tube 4.
[0032] Again, preferably, the track 41 is a shaped track and said auxiliary element 2 is
provided with a counter-shaped surface suitable for housing said shaped track. Again,
in a preferred embodiment of the present invention the track 41 further comprises
at least one low-friction surface
411.
[0033] Preferably, the surface 411 is positioned between said auxiliary element 2 and said
track 41.
[0034] The surface 411 can consist of a section of the same track 41, for example a surface
that has undergone a surface treatment suitable for reducing a roughness parameter,
or consist in a surface of added material having the desired friction characteristics,
connectable to said track 41.
[0035] For example, according to the present invention, the low friction surface 411 is
a teflon surface.
[0036] Again, alternatively, the low friction surface 411 is a graphite surface.
[0037] In addition, preferably the device 5 further comprises adjustment means
21 of the position of said auxiliary elements 2 on said tracks 41.
[0038] The adjusting means 21 are suitable for allowing the auxiliary element 2 to be locked
in position and unlocked from said position, in order to allow the movement of an
auxiliary element 2 on the respective track 41 in case of need.
[0039] In fact, the adjustment means 21 according to the present invention further comprise
a system
211 for quick locking and unlocking of the connection between said auxiliary element
2 and said track 41.
[0040] The system 211 can for example be connected to the auxiliary element 2, in order
to move integrally with said auxiliary element 2, as shown in Fig.2.
[0041] The rapid locking and unlocking system 211 can consist of a plurality of components
suitable for creating interference between a component of the system 211 and the track
41.
[0042] For example, the system 211 can consist of a mechanical interference system operated
manually by levers, or a hydraulic system able to move a component, capable of creating
interference, operated by an actuator or something else.
[0043] The system 211 can be operated by a handle, by a button or by any operating means.
[0044] Again, preferably, the device 5 according to the present invention further comprises
at least one slide guide
212 between the auxiliary element 2 and the track 41. Preferably, the sliding guide 212
is a recirculating ball sliding guide, adapted to reduce the friction between the
auxiliary element 2 and the track 41 during the relative motion between these two
elements.
[0045] Again, in an alternative embodiment of the invention, not shown in the figures, the
track 41 is a worm screw and said adjustment means 21 comprise a gear for adjusting
the position of said auxiliary element 2 on said track 41.
[0046] Again, preferably, the device 5 can comprise at least one limit switch
213, as shown in Fig.2, adapted to ensure the right distance between the auxiliary element
2 and the forming tube 3 in a positioning step.
[0047] Finally, according to an alternative embodiment of the invention, adjustment means
21 of the position comprise sensors and control electronics.
[0048] The sensors and control electronics are adapted to adjust the position of said auxiliary
elements 2 on said tracks 41.
[0049] Preferably, the sensors and control electronics are at least able to automatically
adjust the position of said auxiliary elements 2 on said tracks 41.
[0050] The adjustment means 21 can further comprise an electric motor operatively connected
to said electronics, in an embodiment not shown in the figures.
[0051] The sensors, for example, can generally consist of means suitable for automatically
detecting the position of the auxiliary element 2 on the track 41, relative position
with respect to the forming tube 3.
[0052] Said sensors are therefore sensors of the known art such as proximity sensors, photocells
and more.
[0053] Said sensors are functionally connected to the electronics in order to transfer the
detected data.
[0054] The control electronics can include one or more electronic cards, for example programmable
cards and/or microcontrollers, known to the current state of the art and can define
a basic logic, for example by means of suitable firmware.
[0055] Said control electronics is provided at least capable of allowing the control and
coordination of at least the position of said auxiliary element 2 as a function of
the information obtained from said sensors.
[0056] Said electronics can for example be programmed in order to memorize a series of programs
that can be selected by an operator according to, for example, the characteristics
of the worksheet or the shape of the forming tube 3, said programs able to automatically
set and / or control the position of the auxiliary elements 2 on the tracks 41.
[0057] The operation and the advantages of the bagging machine 1 previously described in
structural terms are as follows.
[0058] The device 5 is connected to an automatic bagging machine, in the section wherein
a working sheet is positioned on a forming tube 3 of the bagging machine.
[0059] The device 5 described, by helping to convey the work sheet onto said tube 3, allows,
thanks to the locking and unlocking systems 211, the rapid repositioning of the auxiliary
elements 2, for example after a malfunction, as in the case wherein the work sheet
jams.
[0060] The above repositioning can advantageously be carried out by any operator of the
forming machine, since the operator has to press a button or turn a handle to adjust
the position of the auxiliary element 2.
[0061] Furthermore, advantageously, the intervention times are drastically reduced by not
having to find tools to disassemble and reassemble the auxiliary element 2 from and
on the flange 4 or on a generic support.
[0062] In addition, the innovative connection of the auxiliary elements 2 to the flange
4 by means of the tracks 41, allows to minimize errors in the repositioning of the
auxiliary elements 2, since the angular position of the auxiliary element 2 is in
fact constrained in a plane substantially transversal to the forming tube 3.
[0063] Again, thanks to the systems 211, and specifically thanks to the limit switch 213,
errors in the repositioning of the auxiliary element 2 are minimized, which can therefore
be implemented thanks to the present invention by any worker, once the necessary distance
between auxiliary elements 2 and tube 3 has been defined, distance which uniquely
determines the position of the limit switch 213.
[0064] A further advantage of the present invention is represented by the embodiment of
the device 5 comprising sensors and control electronics.
[0065] Possibly, once the electronics have been programmed, an operator could simply select
the program relating to a particular process and thanks to the sensors, said electronics
would help, for example by means of an acoustic signal, to detect the exact position
of the auxiliary element 2.
[0066] The invention is susceptible of variants falling within the scope of the inventive
concept defined by the claims.
[0067] In this context, all the details can be replaced by equivalent elements and the materials,
shapes and dimensions can be any.
1. A bagging machine (1) designed to produce, beginning with flat sheets, containment
bags, comprising:
- a forming tube (3), around which said sheet is arranged during longitudinal welding,
- at least one auxiliary element (2) of said sheet on said forming tube (3) comprising
a face adjacent to the forming tube (3), designed to aid at least the positioning
and the maintenance in position of said sheet between said forming tube (3) and said
at least one auxiliary element (2),
- a constraint device (5) that attaches said auxiliary elements (2) to said bagging
machine (1),
- a flange (4) transverse to the working direction of said forming tube (3), and bound
to said bagging machine (1) near said forming tube (3) and characterised by:
- said flange (4) is provided with a plurality of tracks (41) lying on said flange
(4),
- said tracks (41) can be connected with freedom of movement to said auxiliary elements
(2), and
- said device (5) comprises adjustment means (21) for the position of said auxiliary
elements (2) on said tracks (41).
2. The bagging machine (1) according to claim 1, wherein said adjustment means (21) additionally
comprise a system (211) for rapidly locking and unlocking the connection between said
auxiliary element (2) and said track (41).
3. The bagging machine (1) according to any of the previous claims, where said track
(41) is a shaped track and said auxiliary element (2) is provided with a counter-shaped
surface designed to accommodate said shaped track.
4. The bagging machine (1) according to any of the previous claims, wherein said device
(5) additionally comprises at least one slide guide (212) between said auxiliary element
(2) and said track (41).
5. The bagging machine (1) according to any of the previous claims, wherein said at least
one slide guide (212) is a recirculating ball slide guide.
6. The bagging machine (1) according to any of the previous claims, wherein said track
(41) also comprises at least one surface (411) with low friction between said auxiliary
element (2) and said track (41).
7. The bagging machine (1) according to any of the previous claims, wherein said low-friction
surface (411) is a Teflon surface.
8. The bagging machine (1) according to any of the previous claims, wherein said low-friction
surface (411) is a graphite surface.
9. The bagging machine (1) according to any of the previous claims, wherein said track
(41) is a worm screw and said adjustment means (21) comprise a gear for adjusting
the position of said auxiliary element (2) on said track (41).
10. The bagging machine (1) according to any of the previous claims, wherein said adjustment
means (21) of the position comprise sensors and control electronics to adjust the
position of said auxiliary elements (2) on said tracks (41).