Patent Description:
Nowadays for the continuous packaging of products with a predominantly longitudinal extension like spaghetti or breadsticks, usually machines are used that comprise a device with a flat region that ends with a collar with a substantially vertical (or horizontal) axis of extension and which is inclined with respect to the plane of arrangement of the flat region.

The collar has a slit, along the wall that lies opposite to the flat region, which is parallel to the axis of extension of the collar.

Inside the collar there is a hopper with an axis of extension that substantially coincides with the axis of extension of the collar.

To package the products, in a continuous process, a sheet of paper-like and/or polymeric material is unwound from a spool and slides over the substantially flat region of the device and is conveyed inside the collar and shaped around the hopper, adhering to the internal wall of the collar, making the two opposing longitudinal flaps of the sheet come together inside the slit.

The sheet is heat-sealed in a longitudinal direction at the two opposing facing flaps, creating a tubular package, and is subjected to a first cut and simultaneous heat-sealing, in a transverse direction, at the exit from the collar, creating a bag.

The products are then directed, through the hopper, into the bag being created.

The bag containing the products then slides through the collar and is sealed with a second cut and simultaneous heat-sealing, in a transverse direction, opposite to the previous transverse direction, again at the exit from the collar.

Such conventional techniques have a number of drawbacks.

The collar has an internal profile that is normally rectangular with sharp corners, rectangular with rounded corners, circular or slot-shaped, with some straight sections and along its axis of extension it has first a substantially tubular portion, and then a semi-tubular portion.

The device is obtained by bending and welding sheet metal.

In particular the production process, carried out by an operator, begins with two metal sheets, a first metal sheet for making the substantially flat region and a second metal sheet rolled in a closed shape, via successive folds, to create the profile of the collar.

These two separate components are then welded together.

The process is therefore long and laborious and inconvenient.

Furthermore, it is not possible to mass-reproduce such devices.

Also, the internal profile of the collar is the origin of at least two critical points for the sliding of the sheet (particularly if the sheet is made of paper) at the connecting points between the various folds of the sheet metal, at the interface between the tubular portion and the semi-tubular portion, at least at the ends of the semi-tubular shape, which causes the onset of unwanted wrinkles and creases on the sheet itself, as well as tears or rips, in addition to producing visually unpleasant longitudinal fold lines on the sheet.

Devices with a collar, used for packaging machines are also known from e.g. <CIT>.

The aim of the present invention is to provide a device for packaging machines that is capable of improving the known art in one or more of the above mentioned aspects.

Within this aim, an object of the invention is to provide a device for packaging machines, in which the collar has no critical points for the sliding of the sheet inside it, and which makes it possible to guide the sheet evenly, thus increasing the speed of packaging with respect to similar conventional devices.

Another object of the invention is to provide a device for packaging machines that enables a method for its production that is easier and less laborious with respect to similar conventional devices and which does not entail the need for welds.

A further object of the present invention is to overcome the drawbacks of the background art in a manner that is alternative to any existing solutions.

Another object of the invention is to provide a device for packaging machines that is highly reliable, easy to implement and of low cost.

This aim and these and other objects which will become better apparent hereinafter are achieved by a device for packaging machines, which comprises a substantially flat region that ends with a collar, the plane of arrangement of said region being inclined with respect to the axis of extension of said collar, said collar having a slit along its wall that lies opposite to said region, parallel to the axis of extension thereof, said device being characterized in that said collar has an internal profile with a continuous curve with at least four changes of curvature with respect to circularity.

Further characteristics and advantages of the present invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the device for packaging machines according to the invention, which is illustrated for the purposes of non-limiting example in the accompanying drawings wherein:.

With reference to the figures, the device for packaging machines according to the invention is generally designated by the reference numeral <NUM>.

Such device <NUM> is preferably used in a machine for continuous packaging, not shown in the figures, in which the products are moved horizontally.

However, it can also be used in continuous packaging machines in which the products are moved vertically.

In particular, the invention is used to provide packages made of paper.

The device <NUM> comprises a substantially flat region <NUM> that ends with a collar <NUM>.

The plane of arrangement of this region <NUM> is inclined with respect to the axis of extension of the collar <NUM>, the configuration of which is normally vertical or horizontal.

The collar <NUM> has a slit <NUM> along the wall <NUM> that lies opposite to the region <NUM>, which is parallel to the axis of extension of the collar.

One of the peculiarities of the invention consists in that the device <NUM> is monolithic.

In particular, the entire device <NUM> is made of metallic material, using 3D printing and/or stock-removal machining.

The device <NUM> is obtained, for example, with the use of a machine with computer numerical control (CNC).

It should be noted that, differently from similar conventional devices, such a device <NUM> takes a solid form that is homogeneous and mass-reproducible using 3D printing or using stock-removal machining with CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) methods.

Another peculiarity of the invention consists in that the collar <NUM> has an internal profile with a continuous curve, therefore without straight sections and/or sharp corners, in which there are at least four changes of curvature with respect to circularity.

The internal profile of the collar <NUM> is, for example, elliptical and/or oval and/or defined by four blended circular arcs.

Specifically, the oval is composed of four circular arcs in succession, while the ellipse has infinite changes of curvature, it being the geometric place of points of the plane where the sum of the distances from the two focal points remains constant.

It should be noted that such a profile makes it possible to uniformly distribute the tension of the wrapping evenly on all of the profile of the collar <NUM> during the forming of the bag.

The region <NUM> is shaped like an isosceles triangle with the vertex <NUM>, which is comprised between the congruent sides 15a, 15b of the triangle, coinciding with the central point of the wall <NUM> of the collar <NUM> that is proximate to the region <NUM>, on the inlet rim <NUM> of the collar <NUM>.

The region <NUM> has an angle K between the congruent sides 15a, 15b, which is comprised between <NUM>° and <NUM>°.

The region <NUM> is inclined with respect to the wall <NUM> of the collar <NUM> that is proximate thereto, at an angle W comprised between <NUM>° and <NUM>°.

The device <NUM> comprises two wings 18a, 18b, which are mirror-symmetrical with respect to the plane of symmetry of the region <NUM> that passes through the vertex <NUM>.

These wings 18a, 18b extend starting from the sides 15a, 15b, and have a curved profile that defines the inlet rim <NUM> of the collar <NUM>, for the packaging sheet.

This rim <NUM> has a substantially teardrop-shaped contour with the vertex at the slit <NUM>, which is arranged on a horizontal plane that is parallel to the horizontal plane of arrangement of the vertex <NUM> of the region <NUM>.

The device <NUM> comprises two tabs 20a, 20b, which extend parallel to the axis of extension of the collar <NUM> and define substantially the wall <NUM> of the collar <NUM> that lies opposite the region <NUM>.

The slit <NUM> extends in the interface region between the two tabs 20a, 20b, and passes through the thickness of the wall <NUM>.

The tabs 20a, 20b have a surface directed toward the axis of extension of the collar <NUM> with a curved profile.

In particular, the tabs 20a, 20b extend starting from a plane that is perpendicular to the axis of extension of the collar <NUM> and is arranged proximate to/at the end of the wall <NUM> of the collar <NUM> that is proximate to the region <NUM>.

In practice the wall <NUM> of the collar <NUM>, which lies proximate to the region <NUM>, and the wall <NUM> of the collar <NUM>, which lies opposite the region <NUM>, extend on different levels and are not parallel or are only partially parallel.

The device <NUM> can comprise a hopper, not shown in the figures, which is inserted in the collar <NUM> for introducing the products into the shaped wrapping, and which is also provided by 3D printing.

The use of the device <NUM> is the following.

A sheet of paper-like material is unwound from a spool, neither of which are shown in the figures, slides over the region <NUM> of the device <NUM> and is conveyed inside the collar <NUM> and shaped around the hopper, also not shown, adhering to the internal wall of the collar <NUM>, along its inlet rim <NUM>, and making the two opposing longitudinal flaps of the sheet come together inside the slit <NUM>.

The sheet is heat-sealed in a longitudinal direction at the two opposing facing flaps, creating a tubular package, and is subjected to a first cut and simultaneous heat-sealing, in a transverse direction, at the exit from the collar <NUM>, creating a bag.

The products are then directed, through the hopper, into the bag that has just been created.

The bag containing the products then slides through the collar <NUM> and is sealed with a second cut and simultaneous heat-sealing, in a transverse direction, opposite to the previous transverse direction, at the exit from the collar <NUM>.

In practice it has been found that the invention fully achieves the intended aim and objects by providing a device for packaging machines that has no critical points for the sliding of the sheet inside the profile of the collar, and which makes it possible to guide the sheet evenly, thus increasing the speed of packaging with respect to similar conventional devices.

Furthermore, with the invention a device for packaging machines is provided that enables a method for its production that is easier and less laborious with respect to similar conventional devices and which does not entail the need for welds.

Using such an invention prevents the sheet of paper for the package from being damaged or torn during the provision of the package.

Also, from laboratory tests it has been found that such a device for packaging machines makes it possible to provide packages made of paper at a similar speed to packages made of polymeric material and to transit from one type of package to the other without major losses of time.

Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

Claim 1:
A device (<NUM>) for packaging machines, which comprises a substantially flat region (<NUM>) that ends with a collar (<NUM>), the plane of arrangement of said region (<NUM>) being inclined with respect to the axis of extension of said collar (<NUM>), said collar (<NUM>) having a slit (<NUM>) along its wall (<NUM>) that lies opposite said region (<NUM>), parallel to the axis of extension thereof, said device (<NUM>) being characterized in that said collar (<NUM>) has an internal profile with a continuous curve with at least four changes of curvature with respect to circularity, said device (<NUM>) further comprising two tabs (20a, 20b) which extend parallel to the axis of extension of said collar (<NUM>) and define substantially the wall (<NUM>) of said collar (<NUM>) that lies opposite said region (<NUM>), said slit (<NUM>) extending in the interface region between said two tabs (20a, 20b), said slit (<NUM>) passing through the thickness of said wall (<NUM>) of said collar (<NUM>) that lies opposite said region (<NUM>).