Patent Description:
In particular, the apparatus finds application in the handling of corrugated cardboard sheets of the type called "bare wave" or "single face" in technical jargon, that is the type of cardboard in which the outer cover is missing and in which the corrugation remains exposed. This type of corrugated cardboard is used in packaging in the same state in which it is formed or coupled with a coated paper or other kind.

The present apparatus can be used downstream of a cutter to move the sheets that have been cut so as to arrange them in a configuration in which they are prepared for subsequent use, for example stacked.

In practice, the cutter is arranged and acts downstream of an unwinder in which a reel of single face corrugated cardboard is unwound to be divided into sheets of predetermined length, or downstream of a line that produces corrugated cardboard. The apparatus of the present invention picks up the sheets coming out of the cutter and places them in a conformation suitable for any subsequent processing, storage, or transport.

In general, the apparatus can be used directly in the output area of a cutter or in an area connected to it.

Single face corrugated cardboard is remarkably flexible and deformable because its structure (formed only by a smooth sheet, or cover, joined to a corrugated sheet) cannot guarantee the characteristics of resistance to bending and compression that instead offer the corrugated cardboards in which the wave is enclosed between two covers, such as, for example, those of the simple, double or triple wave type.

Currently, the handling of the sheets of single face corrugated cardboard is carried out by means of wedge-shaped elements which are arranged in correspondence with two opposite edges of the sheet. For handling the sheet, the latter can be arranged in a partially arched configuration to increase rigidity. The handling of the sheets of single face corrugated cardboard is however characterized by objective difficulties in the handling of this type of material which can cause drawbacks relating to the possibility of damage to the product and / or to the production speed.

<CIT> discloses a machine according to the preamble indicated in claim <NUM>.

The present invention relates to an apparatus which allows the handling of the sheets of single face corrugated cardboard in a fast and effective way.

This result has been achieved, in accordance with the present invention, by adopting the idea of realizing a machine comprising an apparatus having the features indicated in claim <NUM>. Other features of the present invention are described in the dependent claims.

Among the advantages of the present invention, the following can be listed without limitation: with the apparatus in question, the sheets of single face corrugated cardboard are clamped securely in correspondence with one of their edges to be moved towards a collection area, with a movement which is suitable not to damage the sheets themselves and which allows a relatively high operating speed; the sheet pick-up means are mechanically activated and therefore allow a secure grip; with the apparatus in question it is possible to clamp and move several sheets even of different widths, managing to effectively move the substantial totality of cut sheets having a width of a submultiple of the width of the entire corrugated cardboard web; the sheets are not damaged by the pick-up and handling means; the apparatus has a relatively limited cost compared to the advantages offered and maintains its innovative features unaltered over time. These and further advantages and features of the present invention will be better understood by every person skilled in the art thanks to the following description and the attached drawings, provided by way of example but not to be considered in a limiting sense, in which:.

In the drawings the apparatus (<NUM>) is shown immediately downstream with respect to the cutter (<NUM>) but its use can also be advantageous in an area not immediately downstream but connected to the exit section of the cutter (<NUM>).

Advantageously, the apparatus (<NUM>) is provided with means for gripping and moving (<NUM>) the sheets (<NUM>), shaped and arranged so as to temporarily clamp an edge (10A) of one of said sheets in correspondence with at least two points and to move the same sheet (<NUM>) for a stretch of a predetermined length so as to arrange it in a subsequent station for processing or collecting the sheets.

In a preferable embodiment, represented in the illustrated examples, the gripping and handling means (<NUM>) are shaped and arranged so as to temporarily clamp the edge (10A) in correspondence with substantially all of its extension, for example in a number of points of the order of ten (ten pairs of jaws in the example). Clamping the sheet (<NUM>) at relatively short intervals allows the sheet (<NUM>) to be held securely, limiting the possibility of damage.

The gripping and moving means (<NUM>) of the sheets (<NUM>) in the example of <FIG>, comprise at least two grippers (<NUM>) fixed to a belt (<NUM>) in a first direction (V) and formed by a fixed upper jaw (<NUM>) and by a lower jaw (<NUM>) which is movable in a second direction (Z) orthogonal to the first towards the upper jaw (<NUM>) to clamp the edge (10A) of said sheet (<NUM>).

The clamping of the sheet (<NUM>) takes place thanks to the mutual approach of the two jaws; the arrangement of the fixed jaw in the upper position and the movable jaw in the lower position can be overturned, i.e. with the upper jaw moving and the lower one fixed. In an alternative solution not shown in the drawings, a pincer system can be provided which approaches the two jaws with vertical movement of both.

Furthermore, as will be described below, the solution which provides for the belt (<NUM>) can be replaced by a movement system which includes linear motors.

In particular, the first direction (V) is horizontal and the second direction (Z) orthogonal to the first is vertical. This is the "standard" configuration since the cutter (<NUM>) normally releases the sheets (<NUM>) with their main plane in horizontal arrangement.

As visible in the drawings, each lower jaw (<NUM>) is connected to a stem (<NUM>) which is vertically movable according to the horizontal displacement of the belt (<NUM>).

In particular, the lower jaw (<NUM>), which is L-shaped in the examples, is supported by a stem (<NUM>) which in turn is connected to a support body (22A) in turn connected to a sliding carriage which slides in a first elliptical guide (<NUM>); connected to the support body (22A) is a slider element consisting of a wheel (<NUM>) which is inserted in a second curvilinear guide (<NUM>). The curvilinear guide (<NUM>) has a variable profile and, in particular, passes between two different heights (the difference of which, D, is indicated in the drawings) determining the mutual approach and separation between the two jaws (<NUM>, <NUM>). In practice, referring for example to <FIG>, <FIG>, when the sheet (<NUM>) exits the cutter (<NUM>) the cursor (<NUM>) is in the lowest part of the guide (<NUM>) and in this configuration the two jaws (<NUM>, <NUM>) are separated; subsequently, moving to the left (in the views of <FIG> and <FIG>, the system rotates clockwise) the clamp is closed. As the gripper moves to the left (again in the reference of <FIG> and <FIG>) following the cam defined by the guide (<NUM>), it lifts and closes, gripping the sheets. In the diagram of <FIG>, the cursor reaches the highest level and drags the lower jaw (<NUM>) upwards (Z direction) causing the clamping of the edge (10A) of the sheet (<NUM>). When the cursor (<NUM>) moves again it reaches a portion of the guide (<NUM>) which has a lower level and brings the lower jaw (<NUM>) downwards, causing the sheet (<NUM>) to be released into the collection station (<NUM>).

In the examples, all the gripping and handling means (<NUM>) are supported by dragging bars (<NUM>) which are fixed to the movement belts (<NUM>) in <FIG>, while are supported by linear motors (<NUM>) in the example of <FIG>. The movement belts (<NUM>) are internally toothed and engaged on corresponding toothed pulleys (<NUM>) connected to motor means (M). In particular, the pulleys (<NUM>) are keyed on shafts (<NUM>) in correspondence with central portions of the shafts (<NUM>) which are arranged between two parallel sides (<NUM>). At the ends of the shafts (<NUM>), externally to the sides (<NUM>), there are two diverter pulleys (<NUM>) which are driven, by means of corresponding belts (<NUM>), by motor means (M). In the drawings, with (12I) the internal face of the side (<NUM>) is indicated and with (12E) the external face.

In the example of <FIG> the apparatus (<NUM>) is arranged downstream of a cutter (<NUM>) and is provided with a guide (<NUM>) on which linear motor agents (<NUM>) are supported and acting. Furthermore, there is a guide (<NUM>) which has an arched portion with an ascending slope so as to determine an upward movement of the sliders (<NUM>) which determine the vertical movement (Z) of the jaws. The guide (<NUM>) can have an ascending and a descending portion (useful for lifting the sheet <NUM>, covering the section and lowering to leave it); the opening and closing of the gripper is in any case determined by the cursors (<NUM>) which are piloted by the curvilinear guide (<NUM>), as in the other example. In other words, pairs of guides (<NUM>) with linear motors are housed inside the two sides <NUM> (better visible, for example, in <FIG>), one on each side and exactly opposite. The curvilinear guide (<NUM>) which acts as cams is also housed inside the sides (<NUM>), with a curvilinear guide placed one on each side, exactly facing. The linear motors move along the guide (<NUM>) and each pair of motors (<NUM>) on the right and left is joined by the drag bar (<NUM>), on which jaws/rod/slider etc. are housed. In practice, the linear motors act as a transmission, replacing the belt and the traditional motors, with the same gripping system.

Advantageously, the linear motors (<NUM>) use the electromagnetic principle. The electromagnetic force produces linear movement, without the use of gears, belts or other mechanical parts. In fact, the motor consists of only two parts: the slider (represented by the motors <NUM>) and the stator supported by the guide (<NUM>). The motors (<NUM>) can be produced with magnetic material, for example neodymium magnets.

In this embodiment of the invention, each support body (22A) is enclosed between two linear motors (<NUM>) and supports, in a similar way to the previous example, the rod (<NUM>) and the gripper opening / closing system (<NUM>), with the difference that it is the lower jaw (<NUM>) that is fixed, with the upper jaw (<NUM>) which is vertically movable. This type of movement allows to add, in a number greater than four, the gripper holder movement bars (22A) on which the jaws / rod / cursor etc. are housed, allowing higher collection rates.

As previously expressed, the apparatus (<NUM>) is advantageously provided with means for gripping and moving the sheets (<NUM>) shaped and arranged in such a way as to clamp the edge (10A) along its entire length in a plurality of points of the order of about ten; in other words, the grippers (<NUM>) are in such a number and arrangement as to collect portions of the corrugated cardboard tape having a full width or equal to a submultiple of this value.

By way of example, referring to the non-limiting example of <FIG>, the apparatus (<NUM>) is provided with a support bar (<NUM>) carrying eleven grippers (<NUM>), spaced apart by a value (L1) which can be equal to <NUM>; each gripper (<NUM>), formed by the two jaws as previously described, has a width indicated with (L2) and which can be equal to <NUM>. In this way the grippers (<NUM>) cover a "front" (L10) equal to <NUM>.

In this way the apparatus (<NUM>) can be used for sheets having a width of any value (obviously in the context of the normally used types of single face corrugated board).

This allows to overcome a limit of conventional machines of the known type which allow to collect sheets formed by the corrugated cardboard web at full width or cut in half. With this apparatus it is possible, for example, to also collect the web cut into three or four parts.

In other words, while with the traditional system from a <NUM> wide paper web it is possible to collect a sheet of <NUM> wide format or two <NUM> format sheets, with this system, in addition to the formats indicated above, it is possible to collect three sheets of <NUM> wide format, or four <NUM> sheets.

In practice, in correspondence of any format (compatibly with the formats on the market) the apparatus (<NUM>) will clamp the sheet with at least three grippers (<NUM>).

In the example of <FIG> the following values have been used as an example: W10 for <NUM>, W3 for <NUM>, W4 for <NUM>, W5 for <NUM>.

In both possible embodiments represented in the drawings (which do not exclude others falling within the scope of the following claims) it is evident that the gripping and handling of the sheets of single face corrugated cardboard are extremely advantageous, both in order of maintaining the integrity of the product, both as regards the operating speed and the safety of the apparatus.

Claim 1:
Machine comprising an apparatus (<NUM>) for handling sheets (<NUM>) of single face corrugated cardboard and a cutter (<NUM>), said apparatus arranged and acting downstream of the exit area of a said cutter which divides a single face corrugated cardboard web into a plurality of sheets, characterized in that said apparatus (<NUM>) is provided with means (<NUM>) for gripping and moving said sheets (<NUM>), shaped and arranged so as to temporarily clamp an edge (10A) of one of said sheets in at least two points and move the sheet (<NUM>) itself for a length of predetermined length so as to arrange it in a subsequent processing or collection station (<NUM>) of the sheets themselves.