Device for making carton from flattened tubular blanks

Abstract: A device for the transformation of a flattened tubular blank into a carton includes a pickup unit 1 for withdrawing a tubular blank 2 from a magazine 3, wherein the blanks 2 are arranged, flat, in a pile 6, and an angle plate 8 for opening the selected blank 2 into the shape of carton 2a, during the transfer of the blank 2 to a station 9, where the carton is placed on a step-driven conveyor 10 running along a packaging line 4, while a pusher 18, actuated synchronously with the pickup unit 1 and the conveyor 10, keeps the carton 2a on the conveyor 10 during the initial forward motion.

Description: The present invention concerns the technical sector dealing with the packaging of articles in cartons formed from tubular blanks supplied flat. More specifically, the invention concerns a device to transform these tubular blanks into corresponding cartons. Automatic machines of various types used for packaging articles already exist, operating according to different techniques, known to technicians in the sector. This machinery generally includes a packaging line, along which the cartons obtained from the flattened tubular blank are conveyed in steps; these blanks are taken from a special magazine in which they are arranged flat in piles. Therefore, such packaging machinery usually includes devices designed to transform the tubular blanks into corresponding cartons. For example, a known device of this type includes means to pick up the tubular blanks, such means consisting of a blade which can move transversely to the magazine, so that it slides into the bottom blank in the pile; this blade can also operate vertically in order to convey the blank it has picked up to the packaging line. During transfer, appropriate guides cause the tubular blank to be opened into the required shape, to form a carton. The open cartons are then transported along the line by step-driven conveying means to a packaging station. In the FR-A-2307700 (basis of the preamble of claim 1) there is described and claimed a device thatd provides boxes in a packaging machine, this device having pivoting arms and cams to draw boxes from container blank magazine located over it and open in its bottom. The device is used in packaging machinery to supplybases in the form of cardboard sleeves from a storagecontainer and to open them to a state ready for filling. The device has oscillating pieces to engage and withdraw the sleeves from the container,and cam devices positioned along the path of the boxesto open them to ready state. The sleeves are drawn out by a single panel. Thereare devices to prevent the glued part of one sleevebeing stuck to another. In the machine and device described above, the cartons need to be kept so that the cross section of their open end is exactly right during transport to allow the articles to be inserted correctly. To make the best use of the volume of the cartons, and consequently save space, the cartons must be only slightly larger than the articles to be packaged. This requirement is particularly important in the packaging equipment which operates at high speed to achieve a high rate of production, such as packaging lines for blister packs and similar items. In this case, the conveying means of the packaging line should be equipped with a means for holding the cartons. However the stress to which the cartons are subjected, especially during the initial forward movement, can easily cause the cartons to shift away from the correct transport position. In the French patent identified above, there is a cam means which keeps the box in the correct position and shape while being pushed towards the conveyor. However this cam means provokes other problems, mainly when the size of the boxes to be erected is to be changed. The object of the this invention is to provide a device to transform a flattened tubular blank into a carton, while maintaining the exact shape of the carton after that this carton has been formed. Another object of this invention is to provide a device which is not only technically simple, but also functional, reliable and versatile in application. These objects are achieved by the device as defined in claim 1. Preferred embodiments of the invention are characterized in the dependent claims. The device described in the present invention enables a flattened tubular blank to be transformed into a corresponding carton, while maintaining the carton in the exact open shape, even during the subsequent transfer to the packaging station. In particular, this device enables high operating speeds to be attained, giving high productivity in packaging lines for articles in blister packs or similar items. These articles are usually supplied in piles, but the open side of the carton formed by this device is perfectly aligned with the pile on reaching the packaging station, thus obtaining a correct insertion into the pile itself. The characteristics of the invention are described below, with reference to the appended drawings, in which: Fig. 1 illustrates a perspective view of the device concerned; Fig. 2 illustrates a side view of a packaging line equipped with the device concerned; Figs. 3, 4, 5, 6 and 7 illustrate subsequent stages in the operation of the device. With reference to the aforesaid figures, 1 indicates broadly a pickup unit designed to withdraw a tubular blank 2 from a magazine 3, in which these blanks 2 are arranged flat in piles. The magazine 3 is located at the start of a packaging line 4 and includes a number of guides 5, between which the pile of blanks, referred to as 6 for clarity, is situated; the guides 5, supported by a framework 7, are fitted with special support bodies for the lower edges of the pile 6. Below the magazine 3, there are means 8 to open the blank 2 into the shape of a carton; these means 8 basically consist of an angle plate, designed to act as a fixed guide for the blank 2 during the transfer of the blank 2 itself to a feed station 9. At the feed station 9 the carton 2a is placed on a step-driven conveyor 10 running along a packaging line 4. The conveyor 10 comprises a belt with crosspieces 11, regularly spaced, acting as supports for the cartons. The conveyor belt 10 also has holes 12, adjacent to the crosspieces 11, through which the upper part of the belt communicates with conventional suction devices, not shown in the drawing; the vacuum produced by these suction devices serves to keep the cartons on the conveyor belt 10. Following feed station 9, the packaging line 4 includes other conveying means 13, longitudinally aligned above the conveyor belt 10; these conveying means 13 also consist of a belt fitted with regularly spaced crosspieces 14, to work together with the conveyor belt 10. The conveyor belt 13 also has holes 12a adjacent to the crosspieces 14, through which the lower part of the belt communicates with the suction means. The pickup unit 1 includes a pair of suction lift cups 15, fitted onto respective arms 16 arranged symmetrically at the sides of the conveyor belt 10. The arms 16 are actuated so as to rotate about a transverse shaft 17 so as to provide the reciprocating motion of the suction lift cups 15 between a raised position below the magazine 3 and a lowered position at the level of the upper part of the conveyor belt 10. At the feed station 9 there is a pusher 18 that is designed to operate on the carton on the conveyor belt 10. The pusher 18 comprises a fork 19 placed at the end of a rod 20 which is actuated synchronously with the pickup unit 1 and with the conveyors 10 and 13, by reciprocating means 21 formed by a pair of arms 22 swivelling on respective pivots 23, constituting an articulated parallelogram. The fork 19 passes through a hole 24 in the lower part of the plate 8 which opens the blank 2. The tooth-like projections of the fork 19 are also fitted with heads 25, by means of which the pushing means 18 operate on the carton. The front side of each head 25 is forward slanting with an overhaging upper edge so that the carton is forced down slightly while it is being pushed forward. The operation of the device to transform the flattened tubular blanks 2 into corresponding cartons is described below with particular reference to figures 3 to 7, illustrating successive operating stages. The pickup unit 1 by means of the suction cups 15 draws the blank 2, located at the bottom of a pile 6 haused in the magazine 3; the blank is held by the suction cups 15 and transferred towards the feed station 9 (Fig. 3). During this transfer stage, the blank 2 comes into contact with the fixed guide consisting of the opening plate 8 and is forced to open into its tubular form, according to the folding lines made during manufacture of the blank (Fig.4). After the blank 2 has been picked up and during its transfer to the feed station 9, the conveyor belts 10, 13 of the packaging line 4 are stationary; in fact the forward movement of the conveyor belts 10, 13 alternates with the shaping stages of the cartons. The open carton, referred to as 2a, is placed on the conveyor belt 10 next to a crosspiece 11, as shown in Fig.2; in this position the carton can be held by the suction created by the vacuum through the hole 12. Then the conveyor belts 10, 13 are driven forward synchronously in such a way as to hold the carton between them. At the same time, the pusher 18 is moved synchronously, touching the side of the carton 2a with the heads 25, above crosspiece 11. The pusher 18 moves parallel to the upper part of the belt 10, because of the movement of the reciprocating means 21 towards the forward position 21a, thus accompanying the forward movement of the carton 2a along the belt 10 (Fig. 5). A very important feature of the pusher 18, is constituted by the fact that the front side of the heads 25 have a forward slant and an overhanging upper edge, so that the pushing action is directed downwards. This lowering action of the pushing force is applied to the carton 2a in order to hold the carton on the conveyor belt 10, during its initial forward movement. The carton is therefore unable to move out of the correct transporting position and maintains its exact open shape, that is to say with right angles, since the pusher 18 moves forward to guide the carton 2a up to the infeed area between the counter-rotating conveyor belts 10 and 13 (Fig. 6). The spacing between belts 10 and 13 is more or less equal to the height of the carton. In this area a crosspiece 14 of the belt 13 is placed over crosspiece 11 of the belt 10, its action replacing that of the heads 25 (Fig. 7). At the same time the next blank is picked up from the magazine 3. In conclusion, the device described in the present invention enables a flattened tubular blank to be transformed into a corresponding carton, while maintaining the carton in the exact open shape, even during the subsequent transfer to the packaging station. In fact after insertion between the conveyor belts 10 and 13, the carton is held in position by the vacuum through the holes 12, 12a which works in conjunction with the elastic lifting action of the belts 10, 13. In this way it is impossible for the cartons transported to move sideways, even at high working speed. The opposite side of the carton is closed during transport to the packaging station.

Claims: Device for making a carton from a flattened tubular blank, said device including: a pickup unit (1) to withdraw a tubular blank (2) from a magazine (3), where said blanks (2) are arranged flat in a pile (6); and means (8) for opening said blank (2) into the shape of a carton (2a), during a transfer stage of said blank (2) to a station (9) where said carton (2a) is placed on a conveyor (10) running along a packaging line (4); a pusher (18) actuated at said feed station (9) synchronously with said pickup unit (1) and said conveyor (10), said pusher operating on the backside of said carton and accompanying the forward movement of the carton in order to keep said carton (2a) on said conveyor (10) during an initial forward motion; said device being characterized in that said pusher (18) has at least one head (25) provided with a forward slanting front side with an overhanging upper edge thus provoking a pushing action directed downwards so as to hold the carton (2a) on said conveyor means (10). Device according to claim 1, characterized in that said pusher (18) includes: a rod (20), bearing a fork (19) fixed at one end of said rod facing said feed station (9), with said fork (19) equipped with respective heads (25), said pusher (18) operating on said carton (2a) by means of said heads (25); reciprocating means (21) formed by a pair of arms (22) forming an articulated parallelogram, said arms (22) swivelling on respective pivots (23) to move said rod (20) according to a reciprocating movement in synchrony with the operation of said pickup unit (1) and conveyor (10). Device according to claim 1, characterized in that said conveyor (10) has several crosspieces (11), regularly spaced, with said carton (2a) being placed at said feed station (9), between two consecutive crosspieces (11). Device according to claim 3, characterized in that said pusher (18) acts on a side of said carton (2a), above a crosspiece (11) of said conveyor (10), with said side of said carton (2a) resting against said crosspiece (11). Device according to claim 3, characterized in that said conveyor (10) has holes (12), each of said holes (12) being adjacent to a respective said crosspiece (11), and allowing suction means to hold said carton (2a) on said conveyor (10) during an initial forward motion. Device according to claim 1, characterized in that it includes a further conveyor (13), longitudinally aligned above said conveyor (10) and counter-rotating in synchrony with said conveyor (10) to assist the pick up and transport of said carton (2a) along said packaging line (4), with said carton being guided by said pusher (18) moving toward said conveyor (10) and further conveyor (13). Device according to claim 6, characterized in that said further conveyor (13) has holes (12a), each of said holes (12a) being adjacent to a respective crosspieces (14), and allowing suction means to hold said carton (2a) located between said conveyor (10) and further conveyor (13) during an initial forward motion. Device according to claim 1, characterized in that said pickup unit (1) includes a pair of suction lift cups (15), fitted onto respective arms (16) arranged at sides of said conveyor (10), and made to rotate about a transverse shaft (17) so that said suction cups (15) perform a reciprocating motion between a raised position below the magazine (3) and a lowered position at level of said conveyor (10). Device according to claim 1, characterized in that said means (8) for opening a selected blank (2) consist of an angle plate, designed to act as a fixed guide for said blank (2) during transfer of said blank (2) to said feed station (9), said angle plate having an opening (24) through which said pusher (18) passes.

Inventors: MACCAFERRI LUCIANO, MACCAFERRI, LUCIANO
Applicants: IMA SPA, I.M.A. INDUSTRIA MACCHINE AUTOMATICHE S.P.A.
Application year: 1991
Main classification: B65B43
IPC codes: B65B43, B31B1