BANDING MACHINE FOR LOGS OF SHEET MATERIAL

Abstract

Banding machine for logs (1) of sheet material fed by a conveyor belt (2) to a packaging apparatus adapted to band it with a banding web (11) up to form a tubular wrapper around it. The packaging apparatus of the banding machine comprises a pusher (7) operated by an actuator (8), which pushes the log (1) in a channel (10) where a packaging sheet (11) is arranged stretched in front of the log, as an obstacle, along all the length of the machine through a passage (12). According to the invention, the conveyor belt (2) and the packaging apparatus (7) are arranged at different heights, respectively at a first and a second height (H1 and H2). Another pusher (14) can be provided, operated by a cylinder piston (15) at a first height (H1), in addition to the pusher (7) at the second height (H2), independent from each other. Furthermore, a lifting member (13) is provided, which receives the log (1) from the first pusher (14) and moves from the first height (H1) to the second height (H2). At its inlet in the banding machine the log (1) can be not compressed and is compressed up to reaching a compact shape indicated as (1′) when passing from the first height (H1) to the second height (H2). In particular, the lifting member (13) while lifting the log compresses at the same time the log (1) against a fixed wall (16), up to causing the log to achieve a compact configuration (1′).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristic and the advantages of the banding machine, according to the invention, will be made clearer with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings, in which like reference characters designate the same or similar parts, throughout the figures of which:

FIGS. 5 and 6 show diagrammatically in a longitudinal cross sectional view two successive steps of operation of a banding machine according to the invention;

Figures from 7 to 11 show diagrammatically a cross sectional view with respect to the log of five operative successive steps of the banding machine of FIGS. 5 and 6 according to the invention;

Figures from 12 to 17 show diagrammatically a cross sectional view with respect to the log of six operative successive steps of an exemplary embodiment of the banding machine according to the invention.

DESCRIPTION OF A PREFERRED EXEMPLARY EMBODIMENT

As shown in FIGS. 5-11, relatively to a first exemplary embodiment of the invention, a log of interfolded material 1, just produced by an interfolding machine, comes on a conveyor belt 2 in the banding machine, for example a machine of prior art, or an improved banding machine as that described in an european patent application filed on the same day in the name of the same applicant.

At its inlet in the banding machine log 1 is not compressed and has to be compressed up to reaching a compact shape indicated as 1′, for being then fed to a packaging apparatus adapted to band it with a banding web 11 up to form a tubular wrapper around it, in a way similar to that indicated in figures from 2 to 4. The packaging apparatus comprises a pusher 7 operated by an actuator 8, which pushes log 1 in a channel 10 where a packaging sheet 11 is arranged stretched in front of the log, as an obstacle, along all the length of the machine through a passage 12.

According to the invention, conveyor belt 2 and the packaging apparatus are arranged at different heights, respectively at a first and a second height H1 and H2.

A first pusher 14 is provided, operated by a cylinder piston 15 at first height H1, in addition to pusher 7 at second height H2, independent from each other. Furthermore, a lifting member 13 is provided, which receives log 1 from the first pusher 14 and moves from first height H1 to second height H2.

In more detail, as shown in FIGS. 5, 7 and 8, lifting member 13 receives log 1 from conveyor belt 2. When passing from the first height to the second height (FIGS. 6 and 9) lifting member 13 compresses at the same time log 1 against a fixed wall 16, up to reaching a compact configuration 1′.

Then, second pusher 7 starts moving (FIG. 10), causing packaging sheet 11 to band the log, in a known way. In particular, pusher 7 pushes the compacted log 1′ into channel 10 against packaging sheet 11, stretched in front of log 1′ through passage 12, so that log 1′ is wound for ¾ by sheet 11. Then, after the withdrawal of pusher 7, a system of plates 9 (shown only in FIG. 11) transversal to channel 10, pushes the remaining wings of sheet 11 adjacent to log 1′, on which glue was previously spread in a way not shown, causing them to adhere in turn on the free side of log 1′. Logs 1″ compressed and previously banded (FIG. 10), are pushed progressively forward up to the outlet of channel 10.

The advantage of the invention consists of the fact that, while lifting member 13 is being raised, creating compressed log 1′, a next log la can arrive on the web 2 (FIG. 9), and while pusher 7 is causing log 1′ to be banded (FIG. 10), lifting member 13 can lower again for then receiving (FIG. 11) next log 1a.

In an exemplary embodiment of the invention, shown in figures from 12 to 17, two different means for packaging are provided which are located respectively at second height H2, consisting of channel 10 and pusher 7, and at a third height H3, consisting of channel 20 and pusher 17, where the third height H3 is, in particular, lower than first height H1. The lifting means comprises two lifting platforms 13, 23 adapted to operate independently from each other, initially located respectively at the first and at the third height H1 and H3.

In more detail, as in the previous case, lifting member 13 receives log 1 from conveyor belt 2 (FIGS. 12 and 13). When passing from first height H1 to second height H2 (FIG. 14) lifting member 13 compresses log 1 against fixed wall 16, up to reaching a compact configuration 1′.

Then, second pusher 7 starts moving (FIG. 15), causing packaging sheet 11 to band the log, in a way similar to that described with reference to FIGS. 9 and 10.

In the meantime, while lifting member 13 is raising creating compressed log 1′, a log 1a is waiting on belt 2 (FIG. 14). Second lifting member 23 is then brought to first height H1 for receiving it and when pusher 7 has started to band log 1′, pusher 14 moves log 1a onto second lifting member 23 (FIG. 15). In the meantime, a log 1b is waiting on web 2 (FIG. 16). Second lifting member 23 is at the same time brought to third height H3 along with log 1a and, when pusher 7 has started to band log 1′, first lifting member 13 can lower again to first height H1, compressing log 1a that was present on the lifting member 23 at the third height H3, creating a compressed log 1′a (FIG. 16). Finally, while pusher 17 is causing log 1′a to be banded (FIG. 17), lifting member 13 already, which has been lowered back to height H1, can receive next log 1b.

This solution is particularly compact and integrates two banding apparatus, allowing to receive logs on the conveyor belt at higher rate and to deliver them immediately.

Notwithstanding in the description reference has been made to a step of compression of the log in the passage from the first at the second height, it is not excluded that the log can arrive already compressed on conveyor belt 2. Even in this case, the log is fed to the banding machine at different heights with respect to pusher 7 allowing a higher productivity for the fact that conveyor belt 2 or other conveyor belts must not await the end of the stroke of pusher 7 in the two directions in order to supply a log for banding.

The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Claims

1. Banding machine for logs of sheet material, comprising: a conveyor belt adapted to carry a log in said banding machine;means for packaging the log, said means for packaging being adapted to put a web for banding the log in a position adapted to receive said log and to band it creating a tubular wrapper around it;pushing means adapted to push said log from said conveyor belt towards said means for packaging;characterized in thatsaid conveyor belt and said means for packaging are arranged at different heights, respectively at a first and a second height;Said pushing means have at least a first pusher at said first height and at least a second pusher at said second height independent from each other;lifting means are provided adapted to bring a log from said first to said second height, at said first height said first pusher pushing the log from said conveyor belt to said lifting means, and at said second height said second pusher pushing said log from said lifting means against said web in said means for packaging.

2. Banding machine according to claim 1, wherein when passing from said first height to said second height said lifting means compresses at the same time said log.

3. Banding machine according to claim 1, wherein a fixed wall is provided located at said second height against which said lifting means push said log for compressing it before the intervention of said second pusher.

4. Banding machine according to claim 1, wherein two different means for packaging are provided which are located respectively at said second height and at a third height.

5. Banding machine according to claim 4, wherein said third height is lower than said first height.

6. Banding machine according to claim 4, wherein said lifting means comprises two lifting platforms adapted to operate independently from each other, initially located respectively at the first and at the third height.

7. A method for banding a log of sheet material, comprising the steps of: conveying a log in said banding machine;packaging the log, by bringing a banding web in a position adapted to receive said log and to band it creating a tubular wrapper around it;pushing said log from said conveyor belt towards said banding web for causing said banding;characterized in thatsaid step of conveying and said step of packaging occur at different heights, respectively at a first and a second height;said step of pushing is carried out in part at said first height and in part at said second height independently;a step is provided of passage from said first to said second height between said two pushing steps.

8. Method according to claim 7, wherein when passing from said first height to said second height the compression of said log is provided.

9. Method according to claim 7, characterised in that said steps are executed according to claims from 3 to 6.