EP1144250B1

EP1144250B1 - Apparatus and method for applying endless bands to cartons

Info

Publication number: EP1144250B1
Application number: EP99964255A
Authority: EP
Inventors: Michel Lamamy; Eric Chalendar
Original assignee: Mead Corp
Current assignee: WestRock Packaging Systems LLC
Priority date: 1998-12-17
Filing date: 1999-12-14
Publication date: 2003-09-17
Anticipated expiration: 2019-12-14
Also published as: WO2000035755A1; CA2355671A1; DE69911466D1; GB9827731D0; DE69911466T2; EP1144250A1; ATE249968T1; BR9916332A; AU2053500A

Abstract

Apparatus and method for applying to a carton an endless band so that the band encircles the carton said band being of the type formed by securing a strip of material into a loop and thereby creating a join, the apparatus comprising, means to hold the band in a particular orientation, means to convey the band along a feed path in such a way that said join is maintained in a controlled orientation, means to lower the band on to the carton to be engaged about the midriff of the carton during continuous forward movement.

Description

This invention relates to a machine and method of applying an endless band to an article, in particular a carton, such that the band encircles the article and provides a handle means by which the article can be carried.

The invention is particularly, although not exclusively, useful in conjunction with a carton of the type described in EP A 0 244 047 and apparatus according to the invention may be installed in a packaging system.

EP 0 042 277 illustrates a machine for forming and applying carrying straps to cartons and includes strip measuring means for supplying a strip of pre-determined length from a supply of strip material. The strip is rotated to form a loop and the ends of the strip are secured together for form an endless strap. Thereafter the strap is attached to grouped articles. One example of measuring means is a disc and to change the required length of strip it is necessary to change the disc and to make other adjustments to the machine. This results in a period of machine "downtime" which is an expensive delay in a bottling plant. Such a delay may even result in downtime for the entire bottling line, not just the packaging machine, if problems arise during the changeover period.

Advantageously, the present invention seeks to provide a machine which is capable of switching from one carton type or size with minimal downtime.

The present invention and its preferred embodiments seek to overcome or at least mitigate the problems of the prior art.

One aspect of the invention provides apparatus for forming an endless strap from a supply of strip material, which apparatus comprises first feed means for continuously withdrawing strip material from the supply, a holding station where a surplus amount of strip material can be held in a storage area, second feed means for intermittently drawing a predetermined length of the strip material from the storage area and supplying said length to a strip looping means by which the said length of strip material can be formed into an endless strap and disconnected from the strip material which is immediately to succeed said predetermined length, and control means to co-ordinate the rate of supply of said strip material into the holding station by the first feed means with the desired length of strip material drawn from the holding station by the second feed means.

According to a feature of this aspect of the invention, the holding station may include sensor means to detect an insufficiency of strip material present and to instruct the control means accordingly so that the holding station is replenished with an appropriate amount of said strip material.

According to another feature of this aspect of the invention, the control means may be operative to:

a. introduce a lead end of the strip material to strip gripping means; and engage the gripping means to grip the lead end of the strip;

b. supply a measured length of strip material from said second feed means;

c. rotate the gripping means through 360° to form a loop of strip material;

d. secure a lead end of the strip to the length of strip so as to form an endless strap;

e. sever the strip at a trailing end thereof;

f. bring a second gripping means into engagement with the endless strap; and

g. release the first gripping means and eject the endless strap to be moved forward by said second gripping means.

Another aspect of the invention provides a packaging machine for forming and applying carrying straps to cartons, said machine comprising an apparatus according to any of the three immediately three preceding paragraphs, conveyor means for conveying each endless strap formed by said strip forming means, carton conveyor means for supplying cartons to be fitted with said endless straps, applicator means for applying individual endless straps to successive cartons, and further conveying means to convey the completed cartons from the machine.

Exemplary embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: -

FIGURE 1 is a perspective view of a machine according to one aspect of the invention from a viewpoint wherein the upstream end of the machine is positioned to the right;

FIGURE 2 is a perspective view of the machine shown in Figure 1 illustrating the strap conveying system.

FIGURE 3 is a perspective view of the machine shown in Figure 1 from a viewpoint where the downstream end of the machine is positioned to the left;

FIGURE 4 is a perspective view showing the progress of the strap and carton as it moves progressively downstream in the machine shown in Figure 1;

FIGURE 5 is a perspective view of the strap infeed station of the machine shown in Figure 1;

FIGURES 6a, 6b and 6c are perspective views of the strap forming station of the machine shown in Figure 1;

FIGURES 7a, 7b, 7c, 7d, 7e and 7f are views showing the construction of the strap in the machine of Figure 1;

FIGURE 8 is a flow diagram of the software of a monitoring system for monitoring and rejecting badly welded straps and/or badly positioned straps in accordance with the present invention;

FIGURE 9 is a flow diagram of a control system for controlling the drive means for forming a loop of strap material;

FIGURE 10 is a block diagram of a control system of a control means in accordance with the present invention.

Figure 1 illustrates one example of a machine 10 for forming and applying carrying straps, which machine includes apparatus for forming an endless strap from a supply of strip material and apparatus 12 for applying an endless band 9 to an article, for example a carton 8, so that the band encircles the carton. The machine further comprises means to secure the band or strap to the midriff of a carton. It will be seen from Figures 1 and 2 that the material 6 is fed into the machine in one direction "X", the band or endless strap is constructed and then the direction of the flow of endless straps is reversed to enable cartons moving in an opposite direction "Y" to be engaged with the strap shown in Figure 3. Thus, the infeed and outfeed ends of the machine are adjacent. It is apparent from the drawings that this configuration results in a machine that uses less floor area in a bottling plant, often an important commercial consideration in the machine selection.

Turning to the construction of the upstream end of the machine, shown in Figures 1 and 2, there is included a supply of strip material 6 from source 16, for example a roll, which in this embodiment is mounted onto a shaft 17 secured to the frame 19 of the machine. Optionally, a roller 80 to tension the strip material is included and shown in Figures 1 and 5. The strip material 6 is fed between a disc 84 and follower roll 82 which is biased by suitable means known in the art to grip the strip 6. The disc is driven by suitable drive means, for example a servo motor 88, and is rotated continuously to feed the strip into the machine. In some embodiments the strip material 6 is fed into a storage area 18 prior to feeding it into the machine.

The storage area 18 is illustrated, in more detail, in Figure 5 whereby a surplus amount is held within a strip holding compartment 89 surrounded by a support frame to ensure a continuous supply. The strip is drawn from the holding compartment in an intermittent manner as a desired length of strip material is pushed by suitable drive means 93, 100 into the endless strap forming station 12. Advantageously, the holding compartment facilitates a continuous flow of strip material to be converted to an intermittent supply, thereby making it easier and quicker to transfer the material supply from one source to another with minimum downtime. Therefore, in the illustrated embodiment disc 84 is continuously driven by drive means 88, whereas drive means 100 intermittently drives disc 93. Furthermore, the holding compartment includes sensor means to adjust in flows and the supply of material described below. An alternative configuration is illustrated in Figure 6 whereby the infeed drive means 192 and strap forming drive means 93 are synchronised - the strap forming drive means pushing the strip into the station 12 and the infeed drive means 192 pulling the strip directly from the supply 16.

Suitable control means is provided to control the drive means driving the disc 84 and the drive means 100 driving the disc 93 for pushing the strap into station 22, so as to coordinate the rate of material supply into the compartment with the desired length of strip material leaving the compartment by adjusting the relative velocities of each drive means 88, 100. For example, an increase in the desired length of strap material in station 12 will result in control means causing drive means 100 to increase the velocity of the disc 93 to supply a longer length of material or reduce the time between the intermittent drive of disc 93. It will be appreciated that the intermittent nature of the second drive means 100 requires the velocity profile of second drive means to be greater for shorter time periods compared with the velocity profile of the continuous flow drive means so that the flow of the strap material does not increase too much or for supply to be reduced too much to the holding compartment.

In the event that the second drive means 93, 100 draws too much material from the holding compartment, the amount of strap material 6 contained within the compartment will be reduced. Suitable sensoring means, for example arm 86, is supplied to detect when too little material is in the holding compartment 89. The arm 86 is rotatable about a pivot and is biased in a downward direction. A shortage of material within the holding compartment will cause the material 6 to abut the arm 86 and to move it in an upward direction which causes a signal to be transmitted to the control means. The control means then adjusts the velocity of the disc 84 to increase the amount of strap material supplied to the holding compartment 89. A surplus of material in the compartment 89 will be detected by a user and manual input adjustments can be made via the control means. Preferably, the strip of material 6 passes through two additional pairs of

rollers

90, 92 to rotate the strap from a horizontal plane to a vertical plane ready to be received by the strap forming station 12 shown in Figure 1.

The strap forming station 12 is described in more detail with reference to Figures 6 and 7. The supply of strip material is fed between measuring means, for example a disc 93 and follower roller 95 which is biased by means known in the art. In this embodiment, the disc 93 is driven by an intermittent drive means 100 for example a servo motor to rotate the disc 93 through a certain number of revolutions. Thus, a different length of strip is measured for each incremental movement of the disc. Drive means 100 is controlled by suitable control means so that the disc is rotated to provide the desired linear length of strip material passing between the points of the peripheral contact between the pressure roller 95 and the measuring means. Advantageously, the disc 93 is not required to be interchanged because the control means can determine the desired length at any point in the rotation of the measuring disc 93.

The endless strap is formed by strip looping means generally designated by reference numeral 20. The formation of the strap is best shown in Figures 7a to 7f. In this embodiment, the strip looping means 20 comprises suitable gripping means 94, for example, a pincer or pair of jaws secured to a rotatable shaft 96 and driven by suitable drive means for example, a servo motor 98. In this embodiment, at the beginning of the cycle, the jaws of the pincer are opened to receive a leading end of the strip and the pincer is then closed shown in Figure 7b. Suitable drive means, for example, a brushless type motor 114 is provided to permit the pincer to open and close. Thereafter, the pincer 94 is rotated in a cycle of 360° by drive means 98 and, at the same time disc 93 pushes the desired length of strap 6 beyond the pincer shown in Figure 7c. The length of strip is preferably guided by suitable guide means, for example a fixed guide 130 as shown in Figure 7d to create a loop.

Once the pincer has completed the 360° cycle, shown in Figure 7e, the end of the strip is brought into face contacting relationship with the length of strip and is connected thereto by suitable securing means 104.

In this embodiment, the strip material is, preferably, formed from plastics material so that a sonic welding device can be used as the securing device to weld the end of the strap to the desired length in a known manner. It will be appreciated that other types of strip material, for example fibrous tape can be used without departing from the scope of invention.

The securing means is moved into and out of position of operation by suitable drive means for example brushless type motor 108. Thereafter the strap is cut by suitable cutting means, which in this embodiment is a cutter 110 moved into and out of the position of use by suitable drive means 112 which in this embodiment is a brushless type motor. It will be seen from Figure 7f the strap is formed with the welding device juxtaposed the pincer to provide a known position on the strap 9 for the securing point.

The operation of forming a loop is controlled by suitable control means and Figure 9 illustrates one preferred embodiment of the flow diagram for controlling the loop forming drive means. Reference to pincer includes other known gripping means for purposes of this drawing and the accompanying specification.

The discs and rollers of the present invention are provided with high friction material along the strap contact edges, commonly rubber or other suitable plastics material.

Before the first gripping means 94 releases the endless band and it is ejected from the loop forming station, a second gripping means mounted on an endless chain 28 enters the loop and engages the endless strap. The second gripping means, for example pincer 27 is opened and closed by suitable drive means, for example a pneumatic cylinder controlled by suitable control means and illustrated in Figure 2. The looped strap is engaged by the pincer 27 and it is then closed to retain it. Once the pincer has moved a certain distance by the conveyor 28 and selected by control means, the position of the securing point or weld is a known distance from the second pincer 27, so that it can be correctly positioned on the carton at the preferred location, described below. It is envisaged that a larger looped strap 9 would necessitate the second pincer 27 being moved further along the conveyor before being closed, to ensure the strap 9 is properly engaged with the pincer 27: the position being controlled by suitable control means described below.

As the strap 9 is moved along the conveyor by the pincer it is preferably held laterally to give it an elongate form, shown in Figure 4.

Thereafter, the gripping means 94 of the loop forming station 20 is opened and an ejector 110 displaced from its rest position by drive means pushes the loop in an upward direction to eject it from the loop forming station.

As the strap is moved along the conveyor it is transferred to an overhead plunger unit 22. The unit comprises a plurality of plunger devices 30, shown in Figures 1, 2 and 3, each of which is of similar form and is carried by upper and lower endless chain and sprocket sets 36 powered by suitable drive means for example one or more servo motors (not shown). The plunger devices are caused to move continuously around the unit in a cyclical reciprocating manner. In the preferred embodiment, the frame 34 commences the strap pick up by being lowered so that the lugs are placed within the loop, shown in Figure 2.

The plunger device 30 comprises suitable strap receiving and gripping means, for example pincers or more preferably a plurality of lugs 32 mounted to a frame 34. The strap engaging means is driven in this embodiment, by pneumatic cylinders whereby the lugs 32 are moveable outwardly in direction Z as illustrated in Figure 4. In use, the lugs are placed within the loop 9 and are moved outwardly to engage the strap and to deform the loop 9 so that it conforms substantially to the shape of the carton to which it is to be applied. In this embodiment, four lugs are provided to shape the endless band in a rectangular form. The lugs 32 continue to be moved outwardly and away from each other until there is no more slack in the loop. At that point the second gripping means 27 mounted on the endless conveyor 28 is opened to release the strap and the frame 34 is caused to move away from the conveyor.

It will be seen from Figures 1, 2 and 3 that during movement around the unit, the frame is caused to be reciprocally moved by means of a cam track 50 disposed between the chain and sprocket sets and engaged by a roller follower (not shown) carried by the arms of the frame 34.

Once the strap is fully engaged by the lugs 32 and it has been released by the second gripping means 27, the frame is caused to be raised by the cam track 50 and follower and is moved to the carton loading station 14, shown in Figure 3 where the endless band 9 is caused to be lowered by the cam track 50 and roller follower. Thus, the strap and lugs are lowered around the carton 8 which is moved forward in a continuous manner described below, with the lugs being lowered at each end of the carton. Once the strap 9 is positioned at the desired location on the carton the lugs 32 are moved inwardly by the drive means, or are returned to their rest position by suitable known biasing means to be released from the strap 9. The carton and strap continue to move downstream, the lugs 32 are raised out of engagement with the carton and strap as the frame 34 is caused to be moved upwards by the cam track 50 and follower. The aforementioned application process is desirable, because the strap is applied to the carton in a positive and controlled manner, thereby minimising the chance of the strap being applied incorrectly or to the wrong location. Furthermore, the position of the securing point or weld is known throughout the forming and application process so that the weld can be positioned at a particular preferred location and not, for example along the handle part of the strap. In this embodiment, the weld would preferably be positioned along a side wall of the carton.

As the carton moves downstream the plunger unit 22 is raised and returns to the strap forming station 20. The carton 8 and strap 9 continue downstream and pass through a plurality of air dryers: the temperature of the air dryers is regulated by a user, so that the strap is shrunk around the pack. Optionally, one or more sensors (not shown) is provided to check the positioning of the strap on the pack so that it is in the correct position. Thus the cartons are secured to complete the packaging operation.

It is envisaged that the packaging operation throughout the machine is controlled by a computer programme which controls the speed of the upper and lower sprocket sets and the throughput of the straps to ensure the straps are aligned with the carton. To adapt the machine for a change in the carton size or shape, a different lug plate is used which can be connected to the machine by means of quick release means known in the art. Thus the machine downtime is minimised.

Turning to the conveyance of the carton, as shown in Figure 3, the upstream end of the carton conveyor preferably includes carton infeed means 24 which in this embodiment comprises a pair of opposed belt sets 38. The belts are formed from high frictional material, for example, rubber, and feed the cartons at a controlled rate, determined by the control means, by a carton conveyor 40. Thus, cartons are released by the belts 38 one at a time to be indexed by a suitable lug chain assembly 42 well known in the art which is controlled by suitable control means to be synchronised with the plunger device 22. Once the strap has been engaged with the carton it continues to move downstream by

endless chains

46, 48.

The packaging machine of the present invention may further comprise suitable control means for detecting an incorrectly welded strap. Figure 8 illustrates the block diagram of the programme for detecting bad weld. In the event that a bad weld is detected by a weld sensor in the securing means 104, the endless strap 9 is transferred to the second gripper 27 by the method outlined above and is conveyed forward by the conveyor 28. The plunger unit 34 is brought down onto the band but the lugs 27 remain in a closed position for that particular strap 9 so that it is not transferred. As the second gripping means 27 moves forward it is retained in a closed position until the end of the conveyor where the strap 9 is released and deposited outside the machine. There may further comprise suitable control means shown in Figure 8 for determining the strap position on the carton 8, as outline above. A conventional sensor, for example a photo electric cell is commonly used. In the event that the strap 9 is located in the wrong position then the control means causes a divider guide (not shown) to be moved from a rest position to a position of use to move the carton off the outfeed conveyor 48 for recycling.

The packaging machine incorporates suitable control means described above for controlling the various functions of the machine. Figure 10 illustrates the preferred control means having a central processor and manual input means through which specific instructions can be programmed and a display which indicates useful information to the machine apparatus. The central processor and the display can display operational information such as the speed of operation of the machine and its compliance with particular safety requirements, in the normal manner. In addition, the central processor and display can also indicate information specific to the present machine, such as the strap feeder, carton feeder, welding device, conveyor means speed, safety features and power. All of this information is provided through sensors shown generally at 200.

The control means also controls the positions of the moveable components, for example, the divider guide cylinder for rejecting cartons and air cylinder for the second gripping means, as well as the speed of movement of variable speed components. For example, the central processor controls the motors which power the loop feed chain 34, loop forming station 22, second gripping means chain 28, carton conveyors, carton guide belts 24, loop feed motor 84.

The positions and speeds of the devices can be input manually or a specific pre-written programme can be loaded into the central processor for control of the packaging machine. Also for the controlled change over for the machine from one carton type or size to another can be the result of a pre-written programme or manual input signal.

The machine is readily adjustable to accommodate a wide range of carton sizes without undue time being taken to adapt the machine from running one size of carton to running a different size of carton.

Modifications may be made without departing from the scope of invention. In particular, alternative sensors and alternative means of positioning and moving the strap and/or carton may be utilised without departing from the scope of invention, as claimed in the accompanying claims.

In addition, while the preferred embodiment described herein is for loading a strap onto a fully enclosed carton, it would be recognised that the invention is not limited to cartons for bottles. The invention may be used with machines for packaging cans, paperboard bricks and other containers into cartons. Further, the present invention is able to process cartons comprising numerous configurations of groups of articles covering a wide range of carton size and shape without undue time being spent in adjusting the apparatus.

It is envisaged that the present invention, and in particular the storage area 18, the strap forming station and/or strap transfer station can be used in a variety of other packaging machines. Alternatively, these devices can be sold as an individual module to be fitted to new equipment or to existing equipment on a retrofit basis.

Claims

Apparatus for forming an endless strap from a supply (16) of strip material (6) which apparatus comprises first feed means (82, 84, 88) for continuously withdrawing strip material from the supply, a holding station (18) where a surplus amount of strip material can be held in a storage area, second feed means (93, 95, 100) for intermittently drawing a predetermined length of the strip material from the storage area and supplying said length to a strip looping means (12) by which the said length of strip material can be formed into an endless strap and disconnected from the strip material which is immediately to succeed said predetermined length, and characterised by control means to co-ordinate the rate of supply of said strip material into the holding station by the first feed means with the desired length of strip material drawn from the holding station by the second feed means.
Apparatus according to claim 1 wherein the holding station (18) includes sensor means (86) to detect an insufficiency of strip material present and to instruct the control means accordingly so that the holding station is replenished with an appropriate amount of said strip material.
Apparatus according to claim 1 or claim 2 wherein the control means is operative to:

a. introduce a lead end of the strip material to strip gripping means (44); and engage the gripping means to grip the lead end of the strip;

b. supply a measured length of strip material from said second feed means;

c. rotate the gripping means through 360° to form a loop of strip material;

d. secure a lead end of the strip to the length of strip so as to form an endless strap;

e. sever the strip at a trailing end thereof;

f. bring a second gripping means (27) into engagement with the endless strap; and

g. release the first gripping means and eject the endless strap to be moved forward by said second gripping means.
A packaging machine for forming and applying carrying straps to cartons, said machine comprising an apparatus according to claim 1 to claim 3, conveyor means (27, 28) for conveying each endless strap formed by said strip forming means, carton conveyor means (38, 42) for supplying cartons to be fitted with said endless straps, applicator means (22) applying individual endless straps to successive cartons, and further conveying means (46, 48) to convey the completed cartons from the machine.