GB2130167A - Packing cigarettes in soft packs - Google Patents

Abstract

In a machine for packing cigarettes in soft packs having a pusher (6) to engage a block of cigarettes in a hollow mandrel (3) on a forming drum (1) and to transfer the cigarettes with the pack which has been folded around the mandrel, to a pocket (4) in a drying drum (2), the folded and glued end of the pack is supported during transfer. As illustrated a retractable member (7) associated with each pocket (4), provides said support. Alternatively, each drying drum pocket may be of such a length to receive two packs end-to-end so that a pack previously transferred to a pocket provides the necessary support for the next pack to be received in that pocket. Adhesive may be applied to the folded end closure of the pack in the regions (31-34) by a gravure gummer to cause adherence of the first end closure flap to be folded to an inner wrapper. <IMAGE>

Description

SPECIFICATION Packing machines This invention reiates to the packing of cigarettes in so-called soft packs.

In machines for packing cigarettes in soft packs it is usual to fold each outer wrapper or label into a tubular rectangular shape around a hollow mandrel, about which a foil inner wrapper has already been folded, and to form opposed tucks and folds at one end of the tube so that there are two wide overlapping flaps. These flaps are secured together by adhesive, which was previously applied to the inside surface of the second of the flaps to be folded. A group of cigarettes introduced within the mandrel is then pushed through it so as to withdraw the soft pack from the mandrel for transfer with the enclosed group to a respective aligned pocket of a drying drum.

A problem with such packing machines operating at high speeds is that the adhesive between the two flaps may have insufficient time to set, with the attending risk that the folded end of the outer wrapper bursts open during transfer of the group of cigarettes.

According to one aspect of the present invention there is provided apparatus for packing groups of cigarettes in soft packs, each pack having at one end a folded closure secured by adhesive that may not have fully set upon transfer of the pack, comprising a first intermittently movable conveyor carrying a succession of hollow mandrels, means for forming around each mandrel a soft pack open at its other end and into which is introduced a group of cigarettes, a second conveyor movable intermittently with the first conveyor and carrying a plurality of pockets each of which successively comes into alignment with a respective mandrel at a transfer station, a pusher at the transfer station for transferring a group together with its enclosing soft pack off a mandrel and into a respective pocket while said first and second conveyors are stationary, and restraining means associated with each pocket and disposed opposite said pusher when at the transfer station for engagement with said folded closure of a soft pack being transferred into a respective pocket, so that said folded closure is held against the group therein at least during transfer into the respective pocket.

Each restraining means may comprise a restraining member movable through its respective pocket, guide means disposal parallel to the pocket and along which the member is slidable, and means to apply a frictional resistance between the member and the guide means to oppose movement of the member in a direction away from said pusher.

According to a second aspect of the invention there is provided in a method of packing groups of cigarettes in soft packs, in which an outer sheet is formed as a rectangular tube around an inner wrapper enclosing a group, and in which one end of the tube is closed and secured by tucking in material at the two narrower sides of the pack and folding over the resultant first and second flaps at its wider sides successively into overlapping relationship, said second flap to be folded having adhesive thereon, the improvement of applying adhesive to at least the inner surface of the first flap to be folded, so that said first flap is also secured to the inner wrapper.

The invention also extends to apparatus for performing such a method.

By applying adhesive also to said first flap, the risk of the bottom of the pack bursting open during transfer is further reduced. And it may then be possible to dispense with said restraining means in some circumstances where the packing machine is operating at speeds lower than its maximum.

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is front view of part of a packing machine embodying the invention, Figure 2 is a section taken on the line Il-Il of Figure 1 and drawn to a larger scale, Figure 3 is a developed plan view of one of the drums shown in Figure 1.

Figure 4 is a front view of the machine of Figure 1, on a smaller scale, showing a gumming device for applying a pattern of adhesive to the wrapper sheet which forms the cigarette pack, and Figure 5 shows a wrapper sheet with the adhesive pattern applied to it.

Referring first to Figure 1 , there is shown part of a machine for packing cigarettes in soft packs, including an indexable packet forming drum 1 and a synchronously indexable drying drum 2, which rotate about respective axes 1 A, 2A. As more fully described in U.S. Patent No. 4,330,976 the drum 1 comprises a plurality of rectangular hollow mandrels 3 around each of which a pack P is formed, a group of cigarettes (not shown) being disposed inside each mandrel 3.

The drying drum 2 has a plurality of pockets 4 in its circumference, each pocket being open at its axial ends and at its radial outer side. The drum 2 is indexable in timed relationship with indexing steps of the packet forming drum 1, so that at a transfer station 5 where the two drums overlap, a packet may be transferred from drum 1 to a pocket 4 of drum 2.

With added reference to Figures 2 and 3 the transfer of only one pack P from the drum 1 to the drum 2 will now be described, as the transfer of each pack is identical.

When the drums 1, 2 come to rest a pack P at the transfer station 5 is pushed lengthwise off the mandrel 3 by means of a pusher 6, operated by a cam (not shown), which engages the trailing end face of the group of cigarettes inside the mandrel.

Thus as the pusher moves to the left in Figure 2 the leading end face of the group of cigarettes contacts the inside of the pack and pushes it off the mandrel.

At this time the adhesive holding together the leading bottom folds of the pack P is not completely dry, so there is a danger that the folds may burst open. To make sure that this does not happen, a restraining member 7 is arranged to be contacted by the leading end face of the pack P and pushed through the pocket 4 until the pack comes to rest in the pocket. When the drums 1, 2 stop at transfer station 5 the member 7 is in the position shown in Figure 2. Thus the member 7 is preventing the newly stuck folds from opening during the time that the pack is being transferred from the drum 1 to the drum 2. A member 7 is provided for each of the pockets 4 on the drum 2 and is carried round with the drum 2 as it is indexed.Each member 7 is formed as part of a slide 8 having grooves 9 at opposite sides which run on fixed guide means in the form of rails 10, the latter being carried on the drum 2. The slide 8 is movable in both direction along the rails 10.

To ensure that the member 7 remains in contact with the pack as the latter is being transferred into the pocket 4, the slide 8 is mounted so that a controlled resistance is offered to the movement of the pusher 6. In this respect the bottom face of part of the slide 8 is in close proximity to the upper surface of a platform 11 which supports the rails 10. Positioned between the slide 8 and platform 11 is a thin spring steel runner 1 2 which is caused to be moved with the slide 8 by means of small upturned lugs 13. The runner is pressed into contact with the upper surface of the platform 11 by means of a spring 14 which sits in a recess 15 in the slide 8.In this way the degree of friction, produced in opposition to the force of the pusher 6 when the slide 8 is being pushed along the rails 10, may be controlled by selection of a spring 14 of the required stiffness. To prevent any tendency for the member 7 to move away from the pack P when the latter comes to rest in the pocket 4, a ramp 16 (Figure 2) is positioned in the platform 11 to stop further movement of the slide 8, due to movement of the pusher 6.

When the pack comes to rest in the pocket 4 the pusher 6 is withdrawn and the drums 1, 2 are both indexed round one pitch so that the next mandrel 3 and pocket 4 are positioned in axial alignment at the transfer station 5. The pusher 6 is then again operated to transfer the next pack into the waiting pocket in drum 2.

As the pocket 4 in drum 2, which has just received a pack at the transfer station 5, is indexed away from the transfer station the member 7 is moved away from the pack by means of a fixed cam 17 which is engaged by a cam follower 1 8 rotatably mounted on the slide 8. While the pack is being conveyed intermittently by the drum 2 in the direction shown by the arrow in Figure 3, various further operations are performed to close the open end of the pack, including compieting the drying of the adhesive by a heater 1 9 and removing the pack radially from the drum at position 22 (Figure 3); but these form no part of the present invention so will not be further described.Before the pocket 4 under consideration again reaches the transfer station 5 to receive a further pack from drum 1 , the member 7 is moved back by a further fixed cam 20 through its respective pocket 4 to the position shown in Figure 2.

If for any reason a group of cigarettes and its surrounding pack were missing from a mandrel 3 when it stopped at transfer station 5, the restraining member 7 would then not be moved through the respective pocket 4 in the drum 2 and so might foul other mechanisms round the drum.

Under these conditions the member 7 is arranged to be withdrawn by a fixed cam 21, which is in the form of an extension of the cam 17.

In a modification of the packing machine (not illustrated) the restraining member 7 and associated mechanism are omitted, and the drying drum 2 is instead made wider than described with reference to Figure 2. Each pocket is arranged to be of a length to accommodate two packs P in abutting end-to-end relationship, so that there are two rows of packets in a part of the drum 2 at any one time. The drum is also arranged to be more closely spaced from the ends of the mandrels, for example by a distance of about 18 mm. Instead of the packs being removed at position 22 of the drum, i.e. after they have only moved about one half a revolution, the packs are kept on the drum for about one and a half revolutions and are then removed radially from the second row position, i.e.

to the right of position 22 as seen in Figure 3.

The operation of the modified machine will now be briefly described.

Commencing with the pockets all empty, as on start-up, the machine is at first run at a slow speed for one full revolution of the drying drum, i.e. until the first row of packs in the drum has been filled.

Referring for convenience to Figure 3, a pack P is at this stage already in the drum in a position opposite the pusher 6 (shown in solid lines) with its open end having just been closed. As the pusher is about to transfer the next packet (shown chain-dotted) into the drum a pushing device opposite the pusher 2 moves the first pack towards the pusher 2, taking up said spacing of about 1 8 mm, so that the- two packs are abutting end-to-end. Due to its close fit in the pocket of the drum, the first pack will offer some frictional resistance to the transfer of the next pack, so preventing opening of its newly stuck folds. The first pack then remains for about one half a revolution in the second row position of the drying drum until it is radially removed, as previously described.

Referring now to Figure 4 there is shown the entire packet-forming drum 1 of Figure 1. Above the drum 1 is a guide 25 down which are fed successive labels or wrapper sheets S for forming the outer wrapper layer of the soft pack. Before reaching their respective mandrels 3, each label S passes a gummer 26 which applies a pattern of adhesive to it.

The gummer 26, operating on the known gravure or intaglio principle, comprises a gum dish 27 and a gum wheel 28 (which may be made of a series of coaxial wheels). The wheel 28 has indentations on its periphery at positions where adhesive is to be deposited on to each label. A doctor blade 29 scrapes adhesive from the periphery and from the side flanks of the wheel 28, so that adhesive remains only in the indentations.

Figure 5 shows a label S, viewed in the direction of arrow 5 in Figure 4, after a pattern of adhesive has been applied to it. At the left-hand marginal portion of the label (as viewed in Figure 4) are three stripes 30 for securing the overlapping long marginal portions when the label is initially formed into a tube. The gaps between the stripes 30 are sufficiently wide to enable a pair of narrow gripper rollers (not shown) to contact the label as it is fed towards the respective mandrel 3.

Conventionally adhesive is applied to a label at its end portion (i.e. other than to the stripes 30) in a pattern which only covers a small rectangular area A at an inner surface of what will become the outer flap of the bottom end of the pack. In contrast, in the label of Figure 5 adhesive is also applied to the following areas: to the two rectangular portions 31 which will be tucked in against the bottom of the pack; to a trapezoidal area 32 which extends beyond the conventional area A; and to a further trapezoidal area 33 and to a small triangular area 34 which will lie under the outer part of the area 33 adjacent to the long seam stripes 30.

In the folded pack the adhesive area 33 is caused to bond with the underlying flap of the inner foil wrapper, and so assists in preventing opening of the bottom of the pack during transfer into a pocket of the drying drum 2. The other additional adhesive areas make sure that the bottom of the pack is well stuck down, and give it a neat, flat appearance.

The gravure gummer 26 allows a thin layer of adhesive to be deposited on each sheet, ensuring a rapid drying time, and so also contributing to the bottom of the pack remaining closed during transfer.

As the individual members of the restraining mechanism described above may vary as to the resistance offered during transfer of the pack, the combination with the improved adhesive pattern described above assists in preventing the bottom of the back bursting open. And as previously noted, it may be possible to omit the restraining mechanism in circumstances where a good adhesive bond is made at the lower machine speeds.

Claims (13)

1. Apparatus for packing groups of cigarettes in soft packs, each pack having at one end a folded closure secured by adhesive that may not have fully set upon transfer of the pack, comprising a first intermittently movable conveyor carrying a succession of hollow mandrels, means for forming around each mandrel a soft pack open at its other end and into which is introduced a group of cigarettes, a second conveyor movable intermittently with the first conveyor and carrying a plurality of pockets each of which successively comes into alignment with a respective mandrel at a transfer station, a pusher at the transfer station for transferring a group together with its enclosing soft pack off a mandrel and into a respective pocket while said first and second conveyors are stationary, and restraining means associated with each pocket and disposed opposite said pusher when at the transfer station for engagement with said folded closure of a soft pack being transferred into a respective pocket, so that said folded closure is held against the group therein at least during transfer into the respective pocket.

2. Apparatus as claimed in claim 1 in which each restraining means comprises a restraining member movable through its respective pocket, guide means disposal parallel to the pocket and along which the member is slidable, and means to apply a frictional resistance between the member and the guide means to oppose movement of the member in a direction away from said pusher.

3. Apparatus as claimed in claim 2, further comprising a cam follower mounted on each member and engageable with first fixed cam means adjacent said second conveyor to slide the member away from said transfer station.

4. Apparatus as claimed in claim 3, further comprising second fixed cam means adjacent said second conveyor and downstream of said first fixed cam means for engagement with said cam follower to slide the respective member back through its pocket in order to restrain a subsequent soft pack at said transfer station.

5. Apparatus as claimed in claim 3 or claim 4, further comprising third fixed cam means extending from said first cam means to slide a member at said transfer station through its pocket as the member is moved away from said transfer station, in the event that no group is transferred at said transfer station by the pusher.

6. Apparatus as claimed in claim 1, in which each pocket is of a length to hold two soft packs endwise, and in which said restraining means is constituted by the frictional resistance needed to move a previous pack in a pocket from a first position to a second position remote from said pusher.

7. Apparatus as claimed in claim 6, further comprising a pushing device at the transfer station to urge said previous pack towards said pusher and into contact with the folded closure of a pack about to be transferred.

8. In a method of packing groups of cigarettes in soft packs, in which an outer sheet is formed as a rectangular tube around an inner wrapper enclosing a group, and in which one end of the tube is closed and secured by tucking in material at the two narrower sides of the pack and folding over the resultant first and second flaps at its wider sides successively into overlapping relationship, said second flap to be folded having adhesive thereon, the improvement of applying adhesive to at least the inner surface of the first flap to be folded, so that said first flap is also secured to the inner wrapper.

9. Apparatus for packing groups of cigarettes in soft packs, comprising means for forming an outer sheet as a rectangular tube around an inner wrapper enclosing a group, means for closing and securing one end of the tube by tucking in material at the two narrow sides of the pack and folding over the resultant first and second flaps at its wider sides successively into overlapping relationship, and a gummer device for applying adhesive to both said first and second flaps to be folded, so that said first flap is also secured to the inner wrapper.

10. Apparatus as claimed in claim 9, in which the gummer device is a gravure gummer, known per se, having a doctored gum wheel which feeds adhesive directly from a gum dish to the outer sheet.

11. Apparatus for packing groups of cigarettes in soft packs substantially as herein described with reference to and as illustrated in Figures 1 to 3 of the accompanying drawings.

1 2. Apparatus for packing groups of cigarettes in soft packs substantially as herein described with reference to and as illustrated in Figures 4 and 5 of the accompanying drawings.

13. A method of packing groups of cigarettes in soft packs substantially as herein described.