UNIT FOR FORMING WAVES ON DRINKING STRAWS AND CORRESPONDING METHOD

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority from Italian patent application no. 102023000006498 filed on April 3, 2023.TECHNICAL FIELD

[0002] The present invention relates to a straw corrugating unit and method.

[0003] The present invention finds advantageous application in the packing of straws, to which the following specification will make explicit reference without thereby losing generality.PRIOR ART

[0004] Straws having an intermediate corrugated portion designed to allow the straw to be bent so that, in use, it takes the shape most suitable for the user are well known.

[0005] A well-known packer machine for straws comprises a corrugation unit equipped with a conveyor that advances a series of gripping heads (each suitable for engaging and holding a corresponding straw) along a processing path and between an inlet station, in which each gripping head receives a smooth straw, and an outlet station, in which each gripping head releases a corrugated straw. Each gripping head comprises a support needle which is oriented axially and perpendicularly to the processing path and is movable between an exchange position, in which the support needle is arranged outside a straw, and a holding position, in which the support needle is arranged, at least partially, inside the straw. Each support needle has an intermediate corrugated portion reproducing the corrugated shape that must be imprinted on the straws. In addition, each support needle, in addition to being mounted so that it can move axially, is also mounted so that it can pivot around a central symmetry axis.

[0006] The corrugation unit comprises a plurality of corrugation blades which are arranged parallel to each other and spaced apart in a fixed position along the processing path such that each straw, advancing along the processing path and held by a corresponding support needle (which in the meantime is pivoted to rotate the straw as well), comes into contact with the corrugation blades which, by cooperating on the side opposite the straw with the intermediate corrugated portion of the needle, permanently deform the straw to form the desired intermediate corrugated portion in the straw.

[0007] It has been observed that, by using a known corrugation unit of the type described above, the intermediate corrugated portion of each straw has an irregular (non-uniform) shape, i.e., the corrugation rings have different depths; this defect, although not so evident to the naked eye, is particularly negative because, when the straw is bent or compressed at the intermediate corrugated portion, it loses its initial circular cross-section and takes on a markedly elliptical (and completely unwanted) cross-section.

[0008] In addition, it has been observed that, by using a known corrugation unit of the type described above, the intermediate corrugated portion of each straw has a non-negligible frequency of lesions, i.e. holes that at best only cause straw rejection and at worst cause the packer machine to stop due to the presence of straw shreds in the packer machine that must be removed manually by an operator.

[0009] Patent application WO2021250716 A1 describes a corrugation unit for paper straws; on each straw a flexible shaped portion, defined by a succession of annular ridges and grooves, is made by internal shapers and external shapers that cooperate with each other.

[0010] Patent US10524599B1 describes a corrugation unit for paper straws comprising a plurality of corrugation elements and means to move the straws against the corrugation elements; the corrugation elements are spaced apart from each other both in the lateral direction and in the forward direction.

[0011] Patent application WO2022264079A1 describes a corrugation unit for paper straws comprising a conveyor, which advances the straws along a processing path, and a plurality of blades arranged parallel to the processing path and mounted so that, during use, they remain stationary in relation to the conveyor.DESCRIPTION OF THE INVENTION

[0012] The object of the present invention is to provide a unit and a method for corrugating a straw, which are free from the drawbacks described above and in particular allow a perfectly regular (uniform) shape of the intermediate corrugated portion to be obtained, that is in which all corrugation rings have exactly the same depth.

[0013] In accordance with the present invention, a straw corrugating unit and method are provided as established in the attached claims.

[0014] The claims describe preferred embodiments of the present invention forming an integral part of the present specification.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment thereof, in which: Figure 1 is a perspective view of a straw applied to a beverage package; Figure 2 is an enlarged-scale view of the straw in Figure 1; Figure 3 is a front view of a corrugation unit which creates an intermediate corrugated portion in the straw in Figure 1; Figure 4 is a schematic view of a part of the corrugation unit in Figure 3; Figures 5 and 6 are two views of a part of the corrugation unit in Figure 3 at two different times of operation; and Figure 7 is a schematic view of a detail of the corrugation unit in Figure 3. PREFERRED EMBODIMENTS OF THE INVENTION

[0016] In Figure 1, reference number 1 indicates, as a whole, a straw (made of paper or plastic) which is applied to a beverage package. The straw 1 has a flat end 2 (which is grasped by the user's lips) and a pointed end 3 (to more effectively break through the cap sealing a dispensing opening of the package).

[0017] In addition, the straw 1 has an intermediate corrugated portion 4 at which the straw 1 can be bent / compressed / expanded easily and without breakage (i.e., elastically) so as to take, in use, the shape most suitable for the user.

[0018] The straw 1 is individually packaged (i.e., it has been inserted individually into its own wrapping 5, not shown in Figure 1 and shown in Figure 2) after being bent into a "U" shape (i.e., by 180°) at the intermediate corrugated portion 4 (the purpose of the bending into a "U" shape is to reduce the overall size of the straw 1 so that it remains within the dimensions of the back or front wall of the package to which the straw 1 is applied).

[0019] In Figure 3, reference number 6 indicates, as a whole, a corrugation unit, which creates the corresponding intermediate corrugated portion 4 in each straw 1 and is part of a packer machine, which receives the straws 1 from a manufacturing machine, corrugates the straws 1, optionally bends the straws 1 into a "U" shape and inserts the straws 1 into corresponding wrappings 5.

[0020] The corrugation unit 6 comprises a frame 7 which rests on the ground by means of a set of feet and supports all the various components of the corrugation unit 6. As best shown in Figure 4, the corrugation unit 6 comprises a conveyor 8 which is mounted on the frame 7 and has a plurality of seats 9, each of which is suitable to house a corresponding straw 1; the conveyor 8 advances each seat 9 along a processing path P extending between an inlet station S1, in which the seat 9 receives a smooth straw 1, and an outlet station S2, in which the seat 9 releases a corrugated straw 2. Between the inlet station S1 and the outlet station S2 there is a corrugation station S3 along which the intermediate corrugated portion 4 is created in each straw 1 carried by a seat 9.

[0021] In the preferred embodiment shown in the attached figures, the conveyor 8 comprises a drum 10 which supports the seats 9 and is mounted on the frame 7 so that it can rotate around a central rotation axis 11; accordingly, in this embodiment, the processing path P is circular. According to a different embodiment, not shown, the conveyor 8 comprises a conveyor belt which supports the seats 9 and is looped around two end pulleys; accordingly, in this embodiment, the processing path P is straight.

[0022] The corrugation station S3 covers a relatively large section of the processing path P (i.e., more than 90° of angular extension of the processing path P, which corresponds to more than half of the entire extension of the processing path P) and comprises a plurality of blades 12, each of which has an arc-of-a-circle shape. All the blades 12 are arranged along the processing path P, all oriented parallel to the processing path P (therefore, all parallel to each other), and are mounted (indirectly) on the frame 7 so that, in use, they remain stationary in relation to the conveyor 8, so that each seat 9, when advancing along the processing path P, brings the corresponding straw 1 into contact with the blades 12, resulting in deformation of the straw 1 at each blade 12 (i.e., forming the intermediate corrugated portion 4).

[0023] According to a preferred embodiment, the blades 12 are arranged at least partially offset along the processing path P so that not all the blades 12 simultaneously contact the straw 1 carried by each seat 9 advancing along the processing path P. In particular, all the blades 12 are arranged offset along the processing path P so that each seat 9, when advancing along the processing path P, brings the straw 1 into contact with no more than two blades 12 at a time, and preferably with only one blade 12 at a time. In this way, the intermediate corrugated portion 4 of each straw 1 is not formed all together, but one small piece (one ring) at a time.

[0024] As shown in Figures 5 and 6, each seat 9 comprises a support needle 13, which is arranged parallel to the rotation axis 11 of the drum 10 and is mounted axially movable on the conveyor 8 (i.e., on the drum 10) so that it can move perpendicular to the processing path P (i.e., parallel to the rotation axis 11) between an exchange position (shown in Figure 5), in which the support needle 13 is arranged outside a corresponding straw 1 (and thus leaves the straw 1 free), and a holding position (shown in Figure 6), in which the support needle 13 is arranged, at least partially, inside the straw 1 (and thus engages and holds the straw 1).

[0025] The conveyor 8 comprises an actuator device 14, which moves each support needle 13 axially, arranges the support needle 13 in the exchange position when the seat 9 is in the inlet station S1 or the outlet station S2 at the two ends of the processing path P, and arranges the support needle 13 in the holding position when the seat 9 is between the inlet S1 station and the outlet station S2. In other words, when a straw 1 is to be gripped by the corresponding seat 9 (i.e., in the inlet station S1), the actuator device 14 moves the support needle axially from the exchange position to the holding position to internally engage the straw 1 located in the inlet station S1; instead, when a straw 1 is to be released from the corresponding seat 9 (i.e., in the outlet station S2), the actuator device 14 moves the support needle axially from the holding position to the exchange position to disengage the straw 1 located in the outlet station S2. Of course, between the inlet station S1 and the outlet station S2, the actuator device 14 holds each support needle 13 in the holding position to engage the corresponding straw 1.

[0026] Importantly, between the inlet station S1 and the outlet station S2 (and in particular downstream of the corrugation station S3), the actuator device 14 can modify the holding position by sliding the support needle 13 axially while keeping the support needle 13 inside the straw 1 to keep the straw 1 internally engaged by the support needle 13; this movement of each support needle 13 is intended to allow axial compression of the straw 1 downstream of the corrugation station S3 and at the intermediate portion 4.

[0027] Each support needle 13 is rotatably mounted on the conveyor 8 so that it can pivot around a central rotation axis 15 (parallel to the rotation axis 11 of the drum 10). The conveyor 8 comprises an actuator device 16 which rotates each support needle 13 on itself and around the rotation axis 15 when the seat 9 is in the corrugation station S3 (i.e., when the seat 9 passes through the corrugation station S3). The rotation of each support needle 13 at the corrugation station S3 results in a corresponding rotation of the straw 1 internally engaged by the support needle 13 and thus allows the blades 12 to deform the straw 1 by 360°, i.e. along the whole circumferential extension of the straw 1 (therefore, the corrugation of the straw 1 has a series of adjacent circular deformations).

[0028] The actuator devices 14 and 16 giving the support needles 13 an axial translation movement and a rotation movement, respectively, are preferably made by cams; that is, fixed cams are provided, which are arranged around the rotation axis 11 of the drum 10 and generate the motion required by the actuator devices 14 and 16 by exploiting the rotation of the drum 10 around the rotation axis 11.

[0029] Each support needle 13 has an indented intermediate portion 17 (i.e., it has an alternation of valleys and peaks), which is arranged at the intermediate corrugated portion 4 of a straw carried by the support needle 13 and is configured to cooperate with the blades 12 for the formation of the intermediate corrugated portion 4. In other words, the indented intermediate portion 17 of each support needle 13 is a matrix (mould) which negatively reproduces the shape of the intermediate corrugated portion 4 of the straw 1, and the blades 12 are the punches which deform the straw 1 against the matrix (the indented intermediate portion 17).

[0030] Once the intermediate corrugated portion 4 has been created along the corrugation station S3, each straw 1 may be subjected to axial compression of the intermediate corrugated portion 4 between the corrugation station S3 and the outlet station S2; to this end, immediately downstream of the corrugation station S3, the actuator device 14 modifies the holding position by sliding the support needle 13 axially in order to retract the indented intermediate portion 17 of the support needle 13 from the intermediate corrugated portion 4 of the straw 1 and thus allow the intermediate corrugated portion 4 to be compressed without impediments.

[0031] As shown in Figure 7, each blade 12 has an operating wall 18 that comes into contact with the respective straws 1 in the corrugation station S3, i.e., the operating wall 18 of each blade 12 deforms the respective straws 1 in the corrugation station S3 (in Figure 7, the blade 12 is represented straight for the sake of simplicity, but in fact has a circular shape in order to be parallel to the corrugation path P). The operating wall 18 of each blade 12 is not smooth but is indented (sawtooth-shaped), i.e., it is provided with notches 19 and therefore is edged with a series of notches and projections. In particular, each notch 19 has a rounded tip (top) to prevent damage, in use, to the straw 1.

[0032] Due to the indented shape of the operating wall 18 of each blade 12, in use, the operating wall 18 "clings" to the straw 1 (i.e., it exerts greater friction against the outer wall of the straw 1), compelling (forcing) the straw 1 to roll (rotate on itself) along the operating wall 18, i.e. preventing the straw 1 from crawling without rolling (rotating on itself) along the operating wall 18. In other words, the straw 1 cannot slide (crawl) on the operating walls 18 of the blades 12 but "meshes" with the notches of the operating walls 18 as if it were a gear and rolls (rotates on itself) with no hesitation.

[0033] In the preferred embodiment shown in the attached figures, the operating wall 18 of each blade 12 is at least partially indented, i.e., it is provided with a succession of notches 19; more generally, the operating wall 18 of each blade 12 is not smooth (i.e., uniform, smooth in all its parts) but has a rough conformation (it has a non-smooth, unpolished surface) due to the presence of an indentation (as in the preferred embodiment shown in the attached figures) or due to the presence of a knurling (scalloping) which gives numerous protuberances and reliefs (for example, through a series of parallel lines or a very dense hatching).

[0034] According to a preferred embodiment, the corrugation unit 6 operates on a dual line, that is to say it processes two straws 1 at a time, arranged head first, side by side (that is, axially aligned with each other). In other words, the conveyor 8 has a series of pairs of seats 9 (axially aligned with each other) to pick up two smooth straws 1 at a time at the inlet station S1 and then release two corrugated straws 1 at a time at the outlet station S2. According to a different embodiment, the corrugation unit 6 operates on a single line, that is to say it only processes one straw 1 at a time.

[0035] The embodiments described herein may be combined with each other without departing from the scope of protection of the present invention.

[0036] The corrugation unit 6 described above has many advantages.

[0037] Firstly, the corrugation unit 6 described above allows a perfectly regular (uniform) shape of the intermediate corrugated portion 4 to be obtained, that is in which all corrugation rings have exactly the same depth. This outcome is also obtained because the operating wall 18 of each blade 12 is indented: due to the indentation of the operating wall 18, the straws 1 in use cannot crawl along the operating wall 18 of each blade but are "forced" to roll (rotate on themselves) and this ensures that the corrugation is created uniformly around the entire circumference of a straw 1.

[0038] In other words, if the operating wall 18 of each blade 12 were smooth, in use, a straw 1 could crawl (even only partially, i.e. randomly alternating crawling and rolling) along the operating wall 18 of each blade 12, resulting in non-uniform corrugation (deformation) and also, possibly (if the crawling is prolonged) lesions (cuts) to the straw 1. Instead, the fact that the operating wall 18 of each blade 12 is indented ensures that, in use, a straw 1 rolls (moves by rotating on itself) continuously without ever crawling along the operating wall 18 of each blade 12.

[0039] In addition, the corrugation unit 6 described above is simple, inexpensive and compact to manufacture in that, compared to a similar corrugation unit 6, it only requires modifying (with trivial mechanical processes) the conformation of the operating wall 18 of each blade 12.LIST OF REFERENCE NUMBERS IN THE FIGURES

[0040] 1straw 2flat end 3pointed end 4intermediate corrugated portion 5wrapping 6corrugation unit 7frame 8conveyor 9seat 10drum 11rotation axis 12blades 13support needle 14actuator device 15rotation axis 16actuator device 17intermediate portion 18operating wall 19notch Pcorrugation path S1inlet station S2outlet station S3corrugation station

Claims

1. A corrugating unit (6) for a straw (1) comprising: at least one seat (9) suitable for housing the straw (1); a conveyor (8) configured to advance the seat (9) carrying the straw (1) along a processing path (P); and a corrugation station (S3) that is arranged along the processing path (P) and comprises a plurality of blades (12) each having an operating wall (18) that in use contacts the straw (1); the corrugation unit (6) is characterized in that the operating wall (18) of each blade (12) is either at least partially indented or at least partially knurled.

2. The corrugation unit (6) according to claim 1, wherein the operating wall (18) of each blade (12) is at least partially indented.

3. The corrugation unit (6) according to claim 1, wherein the operating wall (18) of each blade (12) is fully indented.

4. The corrugation unit (6) according to claim 2 or 3, wherein the operating wall (18) of each blade (12) is provided with notches (19).

5. The corrugation unit (6) according to claim 4, wherein each notch (19) has a rounded tip.

6. The corrugation unit (6) according to claim 1, wherein the operating wall (18) of each blade (12) is at least partially knurled.

7. The corrugation unit (6) according to any one of claims 1 to 6, wherein the operating wall (18) of each blade (12) is indented or knurled to make the straw (1) roll, rather than crawl, along the operating wall (18).

8. A corrugating method for a straw (1) comprising the steps of: advancing, by means of a conveyor (8), a seat (9) suitable for housing the straw (1) along a processing path (P); and bringing, by means of the seat (9) advancing along the processing path (P), the straw (1) into contact with a plurality of blades (12) that are arranged in a corrugation station (S3), each blade (12) having an operating wall (18) that in use comes into contact with the straw (1); the corrugation method is characterized in that the operating wall (18) of each blade (12) is either at least partially indented or at least partially knurled to make the straw (1) roll, rather than crawl, along the operating wall (18).