GB2117217A - Tip-turning cigarettes - Google Patents

Abstract

Apparatus for conveying rod-like articles, especially cigarettes, includes conveyors (104, 116) which deliver streams of stacked articles to a junction (112) (which maybe provided with retractable conveyor bands (138) which initially extend across the junction to aid filling); the stream on one (116) of the conveyors is delivered from a further conveyor (102), by a rotary disc transfer conveyor (114) which turns articles through 180 DEG for delivery to the conveyor (116). A fourth conveyor moves the combined stacks of articles away from the junction. The apparatus is particularly useful for tip-turning of cigarettes at the exit of a filter cigarette assembling machine. <IMAGE>

Description

SPECIFICATION Apparatus for conveying rod-like articles This invention relates to apparatus for conveying rod-like articles such as cigarettes or cigarette filter rods.

A typical machine for assembling filter cigarettes delivers two separate rows of filter cigarettes with the filter ends of the cigarettes facing one another. Before the two rows can be combined for further handling of the cigarettes it is desirable that the cigarettes in one row are turned so that their filter ends face the same way as those in the other row; this process is "tip turning". The present invention is usefully (but not exclusively) applied to "tip turning" of filter cigarettes.

According to the invention apparatus for combining substantially parallel streams of rodlike articles in stack formation, comprises a first conveyor for a first stream at a first level, a second conveyor for a second stream at the first level, a third conveyor for said second stream at the first level, means for transferring the second stream from the second to the third conveyor, a junction between said first and third conveyors, and a fourth conveyor for moving the first and second streams combined away from the junction at a second level.

In a preferred arrangement the first, second and third conveyors are substantially parallel, with the first and second conveyors moving in the same direction and the third conveyor moving in an opposite direction. The first and third conveyors may be opposed and separated by the first junction. A chute may lead down or an elevator lead up from the junction to the fourth conveyor.

The means for transferring the second stream from the second to the third conveyor preferably comprises a transfer conveyor, which may move the stream through about 1800 around a substantially vertical axis. The transfer conveyor may be substantially as disclosed in British Patent specification No. 2007964. Alternatively, the transfer conveyor may define a substantially similar path to the conveyor disclosed in said specification but consist of flexible plastics material in the form of a disc constrained to move along a banked path around a substantially vertical axis. The central portion of the transfer conveyor preferably comprises a hub having inwardly inclined sides which may support the inner ends of the articles on the banked portion of the conveyor.Transfer from the second conveyor onto the transfer conveyor and from the transfer conveyor onto the third conveyor may be by way of dead plates adapted to reorientate or straighten the articles during transfer. For example, the line of transfer between the dead plates and the transfer conveyor need not be parallel to the passing articles, so that one end or part of the lowermost articles in the stream is contacted before the other end or parts.

The apparatus may further include means for priming the junction, including means restricting passage through the junction until sufficient articles have accumulated in or upstream of the junction, so that leading articles are bounded and controlled to prevent misalignment.

The priming means may comprise means restricting exit from the junction and may further comprise means responsive to pressure of articles in or adjacent the junction. In a preferred arrangement the priming means includes at least one conveyor band which may extend across the junction and which may be retracted. The conveyor band may be a resiliently-loaded drive band which extends across the junction to substantially close it until the pressure of articles in the junction overcomes the resilient loading. For example the band could normally be curved by pressure of articles and convey the articles in a curved path leading from the junction to the fourth conveyor. Alternatively, or additionally, a flexible curtain of relatively heavy or other material (e.g.

chain-mail) could extend in the junction. Another possibility is a sensor or pressure plate associated with the junction (e.g. above it) and linked to mechanism for restricting the width of the exit from the junction; as pressure builds up in the junction the sensor operates the linkage to increase the width of the exit and allow articles to pass from the junction.

Apparatus for combining streams according to the invention and including a junction is particularly suited for use as a tip turner. In this case, in a preferred arrangement, parallel streams of filter cigarettes are received from a filter cigarette assembling machine and a first stream passes to one side of the junction whilst the other stream passes to the other side of the junction, having been turned so that on combining beyond the junction the tips of the cigarettes are at corresponding ends in the combined stack.

Priming means is particularly useful since one stream (the first) will normally arrive at the junction before the other because it has a shorter path length from the assembling machine. The priming means is preferably loaded so as to accept the first stream and pass it through the junction before the second stream reaches the junction; this avoids an undesirable build-up of cigarettes on the first side of the junction.

The invention will now be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view of apparatus for conveying cigarettes; and Figure 2 is a plan view of the apparatus of Figure 1.

The drawings show apparatus for conveying cigarettes away from a machine for assembling filter cigarettes, such as a Molins PA8. A final cut or delivery drum 100 of the plug assembling machine delivers two parallel streams of cigarettes with the filter tip ends of the cigarettes facing in opposite directions. Parallel band conveyors 102, 104 receive cigarettes from the respective stream on the drum 100. An inclined guide 106 transfers the cigarettes from the drum 100 on to the conveyor 102 underneath a flexible curtain 108. The curtain 108 helps initial formation of a stack on the conveyor 1 02. A guide and curtain (not shown) similar to the guide 106 and curtain 108 are associated with the conveyor 104 on which a stack is formed in the same way as on the conveyor 102.Each conveyor 102,104 is formed with half-round pips or flights 110 to aid conveyance of the cigarettes.

The conveyor 104 leads to a junction 112. The conveyor 102 leads to a transfer conveyor 114 which turns the stream on conveyor 102 through approximately 1 80C and delivers it onto a further flighted band conveyor 11 6. The conveyor 11 6 delivers the stream from conveyor 114 to the side of the junction 112 opposite the conveyor 1 04.

The transfer conveyor 114 comprises a substantially circular disc 11 8 of flexible plastics material rotatable about a substantially vertical axis and including a central rotatable frustoconical hub 120. The disc 11 8 is constrained to have a substantially horizontal surface for receiving cigarettes from the conveyor 102 and for delivering cigarettes to the conveyor 1 16.

Intermediate these positions, on the conveying side of the disc the outer surface is elevated by guide means 1 22 to provide a banked path for the cigarettes, thereby allowing a particularly small radius bend. Opposite its banked portion the disc 11 8 is depressed below the level of the conveyors 102 and 1 16 by adjustable guide means 124. The guide means adjacent the conveyor 102 may be of slightly different shape to that adjacent the conveyor 11 6. For example, an additional guide adjacent the periphery of the disc 11 8 at its point of greatest radius may be required near the conveyor 11 6, to avoid excessive distortion of the disc.The outer periphery of the disc 11 8 is slit to form fingers 126, in order to allow flexing of the disc without kinking.

A stationary guide 1 28 progressively moves cigarettes outwardly of the conveyor 102 for entry onto the disc 11 8 of the transfer conveyor 114.

The flights 110 on the conveyor 102 help to maintain the cigarettes parallel. A dead plate 1 30 is positioned between the end of the conveyor 102 and the disc 11 8 for transfer of cigarettes thersbetween. The trailing edge of the dead plate 130 is inclined at about 140 relative to the axis of the cigarettes; this has been found to aid smooth transfer onto the disc 11 8.

On the transfer conveyor 114 the cigarettes are progressively elevated by the disc 11 8 and then maintained at a constant inclination until the guide means 122 allows the disc to progressively lower and deliver the cigarettes onto a dead plate 132 for transfer to the conveyor 1 6. The plate 132 has a projecting element for helping to strip the cigarettes from the disc 11 8. Inwardly directed side guides 134 align the stream on the conveyor 116.

After the plug assembling machine has been operating for some time opposed streams of cigarettes are delivered respectively by the conveyors 104 and 1 16 to the junction 112. The streams are combined at the junction 112 and descend for delivery by a flighted conveyor 136. At and below the junction 112 a pair of transverselyspaced resiliently-loaded conveyor bands 1 38 define the path from the conveyors 104 and 11 6 to the conveyor 136. On the opposite side of the junction 112 to the bands 138 a flexible curtain 140 (shown in Figure 1 in the position it would assume when the junction is full of cigarettes) is suspended from a position adjacent the end of conveyor 11 6. A stationary guide surface 142 defines the limit of the movement of curtain 140.

The bands 138 pass around two fixed rollers 144 and a movable roller 146 mounted on a pivoted arm 148 and resiliently loaded by a spring 1 50. When the bands 1 38 are not subject to pressure from cigarettes in and below the junction 122 the spring 1 50 causes the roller 146 to move to the position shown in chain-dot lines so that the bands 138 are stretched between the rollers 144 and effectively close the exit from the junction 112, as shown in chain-dot lines in Figure 1. The curtain 140 would then extend vertically downwards from its fixing position adjacent the end of conveyor 11 6.

Assuming that the junction 112 is empty and that the filter assembling machine is then started the stream of cigarettes on the conveyor 104 reaches the junction 112 with the exit substantially closed as just described. Increasing pressure from the cigarettes progressively causes the bands to move downwards and thus open the exit to the junction. In order to direct the pressure onto the bands a horizontally pivoted pressure plate (not shown) may be positioned above the junction 112 to prevent substantial upward movement of the cigarettes at the junction. The apex between the curtain 140 and the bands 1 38 progressively advances with the stream until the junction 112 and the region between the bands 138 and guide surface 142 is fuil, the leading cigarettes being constantly maintained under control to prevent skewing or misalignment.The bands 138 may not be fully retracted against the tension of spring 1 50 until the stream from the conveyor 16 also reaches the junction 112. A curved backing plate (not shown) may define the maximum position of the bands 138 as shown in Figure 1.

As an alternative or in addition to the use of a spring 1 50 the pressure above the junction 112 may be used to control positioning of the bands 1 38. Thus a pivoted curved pressure sensor 1 52 may operate through a linkage comprising levers 154, 1 56, 158 and 148 to move the roller 146.

Thus as pressure builds up over the junction 112 the roller 146 is advanced to the left (as shown in Figure 1) to allow the bands 138 to become curved and open the exit to the junction 112. It should be noted that the sensor 1 52 is asymmetrically positioned over the junction 11 2.

This is so that the sensor 1 52 is optimally positioned for reaction to the stream on conveyor 104, which is the stream for which priming is usually necessary.

It is possible that a sensor could be positioned over the junction 11 2 to control the speed of the bands 138 and/or the conveyor 136. However, since the apparatus is associated with a filter cigarette assembling machine which is delivering cigarettes at a known rate it is normally unnecessary to provide such control, the relative speeds of the conveyors and bands being preset. In this respect it should be noted that the conveyors 102 and 104 normally travel at the same speed, being lower than the peripheral speed of the drum 1 00.

Preferably the speed of conveyors 102,104 is constantly related to the speed of drum 100 (and hence to that of the assembling machine). The conveyor 11 6 travels at the same speed as the conveyor 102, with the transfer conveyor 114 travelling at a corresponding speed. The speed of conveyor 1 36 need not be twice that of the conveyors 104 and 11 6 since the stack height may be increased on the conveyor 1 36. The bands 1 38 may be driven at a speed corresponding to that of the conveyor 1 36 or may be driven at a different speed (either faster or slower). In this respect it should be noted that the bands 138 are not flighted.

Reference is directed to British Patent Specification Nos. 1453191 and 2540831 which disclose band tensioning arrangements which may be incorporated in priming means for the arrangement of Figures 1 and 2.

Reference is also directed to our co-pending Application No. 82 , which includes claims directed to matter disclosed in the present application.

Claims (20)

1. Apparatus for conveying rod-like articles, comprising a first conveyor for conveying a first stream of rod-like articles in stack formation at a first level, a second conveyor for conveying a second stream of rod-like articles in stack formation at the first level, a third conveyor for conveying said second stream at the first level, means for transferring the second stream from the second to the third conveyor, a junction between said first and third conveyors, and a fourth conveyor for moving the first and second streams combined away from the junction at a second level.

2. Apparatus as claimed in claim 1 , wherein the first, second and third conveyors are substantially parallel.

3. Apparatus as claimed in claim 1 or claim 2, wherein the first and third conveyors are opposed at said junction.

4. Apparatus as claimed in any preceding claim, including a path linking the junction and the fourth conveyor, said path including a portion in which articles move with a vertical component of movement.

5. Apparatus as claimed in any preceding claim wherein the means for transferring the second stream comprises a transfer conveyor having a path which is curved about an axis generally transverse to the articles on said conveyor and to their direction of conveyance.

6. Apparatus as claimed in claim 5, wherein the transfer conveyor conveys the second stream on a curve which moves through about 1800 around a substantially vertical axis.

7. Apparatus as claimed in claim 5 or 6, wherein the transfer conveyor comprises a flexible disc constrained to elevate the outer ends of the articles in the second stream on said curved path.

8. Apparatus as claimed in claim 7, wherein the transfer conveyor includes a central portion having inwardly inclined sides for supporting the inner ends of articles on the conveyor.

9. Apparatus as claimed in any of claims 5 to 8, including stationary support surfaces for said second stream arranged between said second conveyor and said transfer conveyor and between said transfer conveyor and said third conveyor.

10. Apparatus as claimed in claim 9, wherein at least one of said surfaces has a transition with said transfer conveyor adapted to engage articles at an asymmetric position to aid transfer to or from the tranfer conveyor.

11. Apparatus as claimed in any preceding claim, including means for priming said junction, said priming means including means restricting passage through the junction until sufficient articles have accumulated in or upstream of the junction, so that leading articles are bounded and controlled to prevent misalignment.

12. Apparatus as claimed in claim 11, wherein the priming means comprises means restricting exit from the junction.

13. Apparatus as claimed in claim 11 or 12, wherein the priming means comprises means responsive to pressure of articles in or adjacent the junction.

14. Apparatus as claimed in claim 11, 12 or 13, wherein the priming means includes at least one conveyor band which may extend across the junction and which may be retracted.

1 5. Apparatus as claimed in claim 14, wherein the conveyor band comprises a resiliently-loaded drive band.

1 6. Apparatus as claimed in any of claims 11 to 15, wherein the priming means includes a flexible curtain of relatively heavy material extending in the junction.

1 7. Apparatus as claimed in any of claims 11 to 16, wherein the junction includes a path for delivering articles towards the fourth conveyor, and means located generally opposite said path for restricting movement of articles away from said path.

18. Apparatus as claimed in claim 1 7 wherein said means comprises a movable member.

19. Apparatus as claimed in claim 18, wherein said movable member is connected to mechanism for restricting exit from the junction zone and constitutes part of said priming means.

20. Apparatus as claimed in claim 1 and substantially as herein described with particular reference to the accompanying drawings.