GB2171168A

GB2171168A - Fluid mandrel

Info

Publication number: GB2171168A
Application number: GB08603825A
Authority: GB
Inventors: Andrew Thomas Gilder; John Edward Nixon; Robert Ernest Williams
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1985-02-16
Filing date: 1986-02-17
Publication date: 1986-08-20
Also published as: GB2171168B; GB8603825D0

Abstract

A tube maker, particularly for making tubes for papirosi, has a mandrel (32) around which the tube (44) is formed and which has air passages (52, 54) for supplying an air bearing for the tube. The mandrel (32) also provides internal support for the tube (44) up to a cut-off (56) and has an angled end face (60 Figure 8 not shown) which lies adjacent the knife path. The mandrel (32) may be retracted (by means 62, 64) to allow operation of rod break-in device during start-up. At least one longitudinal groove (68) may be provided in the mandrel (32) for accommodating part (70, 72) of the tube which forms a fireball trap. <IMAGE>

Description

SPECIFICATION Tube manufacture This invention relates to tube manufacture, in particular the manufacture of continuous rod tubes for production of mouthpieces for cigarettes.

Russian or papirosi-style cigarettes (papirosi) generally include a tobacco portion and an abutting (or overlapping) tube of relatively stiff paper-like material. The tube and the tobacco portion are usually enclosed in a common wrapper of thin paper. It has already been proposed to manufacture papirosi by assembling tobacco sections and tubes using assembly techiques which are used in the tobacco industry to assemble tobacco sections and filter portions. Examples of such proposals are contained in British patent specifications Nos. 1179311, 1179312,1179767,1214491 and 2159386A, to which reference is directed for further details.

According to one aspect of the present invention a machine for making continuous tube comprises a mandrel, means for continuously feeding at least one web of material past or onto said mandrel, means for at least partly wrapping the material around the mandrel into substantially tube-like form, and means for supplying fluid to provide a fluid bearing between the material and the mandrel.

Preferably the fluid is air and is supplied from within the mandrel.

The feeding means, which may comprise a garniture tape, preferably is arranged to feed at least two wrappers. Means may be provided for adhesively securing the wrappers together upstream of the mandrel. Adhesive sealing means for completing the tube may be provided in the region of the mandrel.

The wrapping means may be arranged to progressively form the material into tube-like form on the mandrel, and may comprise folders which cooperate with a garniture tape carrying the wrapper, as conventionally used in continuous rod making machines.

The mandrel preferably extends from a region in which the material is relatively flat to a region in which the tube is completely formed. Additional conveying means, which may cooperate with said conveying means, may be provided to withdraw or convey the completed tube from the mandrel.

The mandrel may comprise a cantilevered, substantially cylindrical member on which the tube is formed, having at least one substantially axial bore and a plurality of transverse bores for supplying air under pressure to provide an air bearing between the material and the surface of the mandrel. Alternatively the mandrel may comprise relatively porous material, so that separately-defined transverse bores may be unnecessary. The provision of an air or other fluid bearing serves to ensure that movement of the material and tube relative to the mandrel is smooth and relatively frictionless.

According to another aspect of the invention a machine for making continuous tube comprises a mandrel, means for feeding at least one web of material past or onto the mandrel, means for forming and sealing the material into a tube on the mandrel, and a cutting device for severing the continuous tube into individual tubes, wherein the mandrel extends to the region of the cutting device and provides internal support for the tube during cutting. The cutting device may 20 comprise a continuous rod cut-off. Preferably the end of the mandrel is shaped so as to correspond closely to the the transverse path of the cut-off knife which severs the tube. Additional support, external to the tube, may be provided by a ledger device, as is conventional in continuous rod cut-offs.

According to a further aspect of the invention a machine for making continuous tube comprises a mandrel, means for feeding at least one web of material past or onto the mandrel, means for forming and sealing the material into a continuous tube around the mandrel, and a continuous rod cut-off device for severing the continuous tube into individual tubes, including means for moving the mandrel in a longitudinal direction. In a preferred arrangement the moving means moves an end of the mandrel towards or away from the cut-off device.This is particularly useful where the mandrel extends into close proximity with the cut-off device, so that retraction of the mandrel can allow deflection of incomplete tube formed during initial startup of the machine. The mandrel may be retracted by a distance sufficient to allow operation of a conventional rod break-in device.

According to a further aspect of the invention a machine for making continuous tube comprises a mandrel, means for feeding at least one web of material past or onto the mandrel, means for wrapping and sealing the material around the mandrel to form a continuous tube, means upstream of at least part of the mandrel for displacing part of the material in such manner that said part will project into the interior of the tube when formed, and at least one longitudinal gap or channel in the mandrel (or that part of the mandrel downstream of said displacing means), whereby said part of the material remains inwardly-projecting during formation or further formation of the tube on the mandrel and at least partly passes through said gap or channel.The inwardly-projecting part of the material may be formed by flaps or portions of the material cut from the web at spaced locations and/or may be formed by an inwardly-directed continuous edge of the web.

Each of the foregoing aspects of the invention may be used or incorporated in a machine incorporating one or more of the other aspects of the invention.

The invention will be further described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side view of part of a tube-making machine, Figures2-7are respectively sectional views on the lines Il-Il, Ill-Ill, IV-IV, V-V, VI-VI and VII-VII of Figure 1, Figure 8 is an enlarged view of part of the machine of Figure 1, and, Figure 9 is a sectional view of a modified mandrel.

Figure 1 shows a machine for producing individual tubes from an inner wrapper web 10 of paper or card and an outer wrapper web 12 of paper or card. The materials of the wrappers 10, 12 could be different.

An adhesive applicator 14 is arranged to apply a line or bead 16 (Figure 2) of suitable gum or adhesive to one edge of the outer wrapper 12. A garniture tape 18 passing around an end roller 19 receives the outer wrapper 12. The inner wrapper 10 passes over an idler roller 20 and is received on top of the outer wrapper 12 at a position which is slightly laterally offset (Figure 3). The inner and outer wrappers 10,12 are conveyed by the tape 18 and also initially by light pressure exerted by a drive roller 22 arranged opposite the garniture tape end roller 19.

Downstream of the roller 22 an upper endless band 24 heated by an element 26 causes the inner and outer wrappers 10, 12 to be bonded together at the adhesive line 16. Subsequently the inner and outer wrappers 10, 12 are carried by the garniture tape 18 into the region of folders 28 of the garniture which, in conventional manner, progressively forms the tape 18 into a U-shape and causes the wrappers 10, 12to be overlapped and eventually to form a tube. As shown in Figures 1 and 4 the wrappers 10, 12 and garniture tape 18 are initially wrapped around a portion 30 of a mandrel 32, which portion has a U-shaped lower end. The portion 30 forms a support for a cylindrical part 34 of the mandrel 32, on which part of the tube is formed.Thus, as can be seen in Figure 5, the folders 28 (not shown in Figure 5) and cylindrical part 34 of mandrel 32 cooperate to progressively form the wrapper 10, 12 into tube-like form.

As also shown in Figure 5, an inner upstanding edge of the outer wrapper 12 is provided with an adhesive bead or line 36 applied from an applicator 38. At a downstream position (Figure 6), where the folder 28 have substantially completed the formation of the tube from the inner and outer wrappers 10, 12, the latter pass beneath a further heated band 40 and heating element 42 to cause the tube to be sealed.

Beyond the end of the folders 28 the sealed tube 44 is engaged between a final drive roller 46 having a tube-engaging (e.g. knurled) outer surface 48 which cooperates with a downstream roller 50 for the garniture tape 18 to withdraw the tube 44 from the garniture and convey it onwards.

It will be appreciated that the tube 44 remains supported by the mandrel 32. In order to reduce any friction which may exist between the mandrel 32 and the wrappers 10, 12 and tube 44 the mandrel 32 is provided with an air supply passage 52 which extends down the support 30 and along the cylindrical part 34 of the mandrel 32. At relatively close spacings along the length of the mandrel 32 there are angularly-spaced transverse bores 54 which supply air to the small space between the wrappers 10, 12 and tube 44 and the mandrel 32, so that a low friction air bearing is provided by the mandrel. The bores 54 could be angled or otherwise arranged so that the air supplied has a component in the direction of movement of the wrappers 10, 12 and tube 44 and hence assists in conveying them.

Downstream of the garniture the tube 44 is cut into individual tubes by a conventional continuous rod cut-off having a cut-off knife 56 and a tube support ledger 58. It will be appreciated that during cutting of the tube the knife 56 and ledger 58 advance in the direction of movement of the tube 44 and at the same speed. The cutting edge of the knife 56 therefore traces an angled path relative to the stationary mandrel 32. The end 60 of the mandrel is angled so that it is very close to the path of the knife during cutting of the tube 44 (at the optimum or normal speed of the machine). In this way the mandrel 32 provides additional support for the tube during cutting and, together with the ledger 58, ensures a clean cut of the tube.

The construction of the completed tube 44 is shown in Figure 7. Other constructions of tube are possible with the present apparatus. In particular, although both inner and outer wrappers 10,12 are formed with butt joints it would be possible to provide that one or both of the joints overlap. In the case of the outer wrapper 12 it would of course be preferable for the material of the wrapper to be relatively thin if a lap joint is to be unobtrusive.

Examples of different constructions of tube are to be found in the previously-mentioned specifications.

During initial start-up of the machine the tube 44 may not be correctly formed; for example the adhesive bead 36 may not be correctly applied or set until the machine has been running for a short time.

It is conventional in continuous rod-making machines to deflect the incorrectly-formed tube and allow the tube to enter the cut-off for production of individual tubes only when the tube is correctly formed (usually a short time after initial start-up).

Normally product is initially deflected just upstream of the cut-off by a device which may also be capable of providing a cut end for entry into the cut-off when the product is satisfactory. An example of such a device is shown in British patent spcification No.

1021741. A device such as this may be incorporated in the present machine. In orderforsuch a device to operate, the mandrel 32 is withdrawn by a sufficient amount to allow operation of the device on the tube upstream of the cut-off. For this purpose the mandrel 32, and in particular the support portion 30, is movable on a track 62 by operation of a piston and cylinder 64. The leading end of the mandrel 32 may then be withdrawn sufficiently to allow deflection and break-in of the tube 44 in conventional manner.

A flexible air supply tube (not shown) may be connected to supply air to the passage 52 at all positions of the mandrel 32. The piston and cylinder 64 may be operated to progessively advance the mandrel back to the position shown in the drawing after inital break-in of the tube 44.

It is common to provide a so-called "fire-ball trap" in tubes for forming mouthpieces for papirosi.

Examples of such traps are shown in the previouslymentioned British patent specifications Nos.

1179312 and 2159386A. In the present machine the mandrel 32 could be modified to provide a slot to allow passage of a flap or edge of wrapper which may eventually form a fire-ball trap in the completed tube 44. For example, in additional roller 66 carrying a knife 67 could be provided upstream of the roller 20 to provide suitable cut-outs in the inner wrapper 10. The positions of the cut-outs could be arranged so that neither the rollers 20, 22 nor the band 24 flatten them, and the mandrel 32 may be provided with longitudinal grooves corresponding in angular position to the position of the cut-outs formed by the roller 66, so that the cut-outs remain inwardly directed during formation of the tube. Figure 9 shows a sectional view of a modified mandrel 132, having an air passage 52 and radial bores 54, and in addition longitudinal slots 68 for receiving cut-outs (as indicated at 70) formed by the roller 66 and knife 67. At least one of the slots 68 could be arranged to receive one edge of the inner wrapper (as indicated at 72), this edge forming the fire-ball trap either alone or in combination with the cut-outs 68.

Claims

1. A machine for making continuous tube comprising a mandrel, means for continuously feeding at least one web of material past or onto said mandrel, means for at least partly wrapping the material around the mandrel into substantially tube-like form, and means for supplying fluid to provide a fluid bearing between the material and the mandrel.

2. A machine as claimed in claim 1, including means for supplying fluid from within the mandrel.

3. A machine as claimed in claim 2, wherein the mandrel includes a part defining a substantially cylindrical shape for the tube and an internal substantially longitudinal passage for fluid.

4. A machine as claimed in claim 3, wherein the mandrel includes a plurality of transverse bores extending between the passage and the surface of the mandrel.

5. A machine as claimed in any preceding claim, wherein the fluid supplying means is arranged so that fluid is supplied in a direction having a component in the direction of movement of said feeding means.

6. A machine as claimed in any preceding claim, wherein the feeding means is arranged to feed at least two webs.

7. A machine as claimed in claim 6, including means for adhesively securing at least two webs together upstream of said mandrel.

8. A machine for making continuous tube, comprising a mandrel, means for feeding at least one web of material past or onto the mandrel, means for forming and sealing the material into a tube on the mandrel, and a cutting device for severing the continuous tube into individual tubes, wherein the mandrel extends to the region of the cutting device and provides internal support for the tube during cutting.

9. A machine as claimed in claim 8, wherein the end of the mandrel is shaped so as to correspond closely to the transverse path of the cutting device as it severs the tube.

10. A machine as claimed in claim 8 or 9, wherein the cutting device includes a continuous rod cut-off including a ledger device.

11. A machine as claimed in claims 8 to 10 and any of claims 1 to 7.

12. A machine for making continuous tube, comprising a mandrel, means for feeding at least one web of material past or onto the mandrel, means for forming and sealing the material into a continuous tube around the mandrel, and a continuous rod cut-off device for severing the continuous tube into individual tubes, including means for moving the mandrel in a longitudinal direction.

13. A machine as claimed in claim 12, wherein the moving means is arranged to move an end of the mandrel towards or away from the cut-off device.

14. A machine as claimed in claim 12 or claim 13, including deflecting means movable across the path of the tube between the mandrel and the cut-off device, said moving means being arranged to retract the mandrel to allow the deflecting means to move across said path.

15. A machine as claimed in any of claims 12 to 14 and any of claims 1 to 7.

16. A machine as claimed in any of claims 12 to 14 and any of claims 8 to 11.

17. A machine for making continuous tube, comprising a mandrel, means for feeding at least one web of material past or onto the mandrel, means for wrapping and sealing the material around the mandrel to form a continuous tube, means upstream of at least part of the mandrel for displacing part of the material in such manner that said part will project into the interior of the tube when formed, and at least one longitudinal gap or channel in the mandrel (or that part of the mandrel downstream of said displacing means), whereby said part of the material remains inwardly-projecting during formation or further formation of the tube on the mandrel and at least partly passes through said gap or channel.

18. A machine as claimed in claim 17 and any other preceding claim.

19. A machine for making continuous tube, substantially as herein described with particular reference to Figures 1 to 8 or Figure 9 of the accompanying drawings.