GB2168588A

GB2168588A - Profiled tobacco layers

Info

Publication number: GB2168588A
Application number: GB08531455A
Authority: GB
Inventors: John David Hooper; Steven Edward Potts; Christopher Ralph Bale; Raymond Allen Bryant
Original assignee: Imperial Group PLC
Current assignee: Imperial Group PLC
Priority date: 1984-12-21
Filing date: 1985-12-20
Publication date: 1986-06-25
Also published as: GB2168588B; GB8432412D0; GB8531455D0

Abstract

An apparatus for making a longitudinally profiled layer of tobacco on a moving conveyor band comprises means for depositing a layer of tobacco (16) on the band (10) and means for periodically preventing the deposition of the tobacco on the band or for periodically removing deposited tobacco from the band, the means being rotatable about an axis lying transversely of the band. The means may comprise either a paddle wheel (12) or an apertured hollow cylinder (20) from which a jet of air is caused to issue. <IMAGE>

Description

SPECIFICATION Improvements in or relating to the manufacture of a rod of smokable material This invention relates to the manufacture of a rod of smokable material, such as is used in cigarettes, and is concerned with the production of a rod of smokable material consisting of more than one type of smoking material in which the types of smoking material in the rod are demarcated.

"Types of smoking material" include those exhibiting different natures or compositions and may, for instance, comprise various kinds of tobacco, tobacco products such as reconstituted tobacco, or tobacco substitutes. The term "tobacco substitute" will be understood to include not only smoking materials such as cellulose or cellulosic derivatives of non-tobacco origin, but inert fillers such as alumina.

The present invention is particularly concerned with the provision of a longitudinally profiled layer of a first type of smoking material on an air pervious conveyor band, such as is in common use in the art. A second layer comprising a second type of smoking material is preferably provided on top of the profiled layer so as to provide a composite rod of smokable material consisting of two demarcated smoking materials whose relative proportions vary in a predetermined manner along the longitudinal axis of the composite rod. The structure and properties of such a composite rod are described in the present applicant's published British patent application number 2124471 A.

According to the present invention there is provided an apparatus for making a longitudinally profiled layer of smoking material on a moving conveyor band, the apparatus comprising means for depositing a layer of smoking material on the band and, rotatable paddle means adjacent the band for periodically preventing the deposition of the smoking material on the band or for periodically removing deposited smoking material from the band, the paddle means being rotatable about an axis lying transversely of the band.

The rotatable paddle means may be arranged relative to the band so as to periodically hold back smoking material on the band so as to create spaced zones on the band free of smoking material.

Alternatively, the rotatable paddle means may be arranged relative to the band so as to periodically remove at least a portion of the smoking material from successive zones of the band so as to profile the thickness of said layer of smoking material.

The rotatable paddle means may be provided by a paddle wheel.

The rotatable paddle means may alternatively be provided in use by a radially directed jet of fluid exiting from an apertured cylinder whose axis of rotation is said axis.

The fluid is preferably air.

The invention will now be described by way of example only with reference to the accompanying drawings, which are purely diagrammatic and not to scale, in which, Figure 1 is a perspective view of an arrangement of a conveyor band together with an associated paddle wheel; Figure 2 is a cross-section along the longitudinal axis of the band of the arrangement of Fig. 1, together with a vacuum box; Figure 3 is a second embodiment of the invention and is a perspective view of an arrangement of a conveyor band together with an associated rotatable cylinder for directing a jet of air at the band; Figure 4 is a cross-section along the longitudinal axis of the band of the arrangement of Fig. 3, together with a vacuum box; and, Figure 5 is a cross-section along the longitudinal axis of the rotatable cylinder of Figs. 3 and 4.

Referring to the first embodiment of the invention shown in Figs. 1 and 2, there are shown a horizontal air- pervious conveyor band 10 and, underneath the band, a rotatable paddle wheel 12 whose axis lies transversely of the longitudinal axis of the band. The wheel 12 is driven to rotate in the direction of arrow 6 by a drive motor (not shown). There is further provided a vacuum box 14 (shown in Fig.

2 only) on the upper side of the band 10 so that air may be drawn upwards through the band.

In operation, a layer of tobacco 16 (shown in Fig. 2 only) is deposited on the underside of the band 10 from an upwardly directed chimney (not shown) as described and illustrated in British patent application 2124471 A.

The tobacco 16 is held on the underside of the band 10 by the vacuum applied through the band.

The paddle wheel 12 is spaced from the band 10 so that the paddles 18 of the wheel contact the band and periodically prevent the deposition of tobacco 16 on longitudinally spaced zones of the band.

Alternatively, the paddle wheel 12 may be spaced further from the band 10 so that a top section (i.e. that furthest from the band) of tobacco 16 on the band is periodically removed by the paddles so as to provide longitudinally spaced regions of reduced thickness of tobacco, that is, a longitudinally profiled layer of tobacco.

Referring to the second embodiment of the invention shown in Figs. 3 to 5, the band 10 and vacuum box 14 (shown in Fig. 4 only) are identical to those in the first embodiment, and tobacco 16 is deposited on the band in the aforesaid manner.

A rotatable hollow cylinder 20 is provided instead of the rotatable paddle wheel of the first embodiment. The longitudinal axis of the cylinder 20 lies transversely of the longitudinal axis of the band 10.

As shown in Fig. 5 the cylinder 20 is provided with an axial bore 22 extending in from one end face and terminating in a chamber 24. The chamber 24 is provided with a slot or aperture 26 parallel to the axis of the cylinder 20 opening on to the surface of the cylinder and extending across the width of the band 10. Hence, any fluid, e.g. air that is pumped into the cylinder 20 through the bore 22 will exit as a jet through the slot 26 in whatever direction the slot is facing. The jet is therefore equivalent in function to the paddles of the first embodiment.

A pressurised air supply (not shown) is supplied to the cylinder 20. The cylinder 20 is caused to rotate about its axis by a motor drive (not shown) in the direction of arrow 6 so that the jet of air from the slot 26 strikes the band 10 at regular intervals, thereby preventing deposition of tobacco on longitudinally spaced zones of the band.

It is seen that both embodiments of the invention provide a layer of tobacco 16 on the band 10 that is regularly profiled in the longitudinal direction of the band. A further layer of tobacco may then be laid on top of the first layer 16 that has been profiled so as to provide a composite layer consisting of two demarcated layers of tobacco which are then formed into a continuous rod and ultimately into cigarettes as described in British patent application 2124471 A.

In the second embodiment the cylinder 20 may be provided with a plurality of said slots 26 spaced round its periphery.

The paddles 18 of the first embodiment may be provided by radial vanes or by bunched resilient filaments.

Claims

1. An apparatus for making a longitudinally profiled layer of smoking material on a moving conveyor band, the apparatus comprising means for depositing a layer of smoking material on the band and, rotatable paddle means adjacent the band for periodically preventing the deposition of the smoking material on the band or for periodically removing deposited smoking material from the band, the paddle means being rotable about an axis lying transversely of the band.

2. An apparatus as claimed in claim 1 wherein the paddle means is arranged relative to the band so as to periodically hold back smoking material on the band so as to create spaced zones on the band free of smoking material.

3. An apparatus as claimed in claim 1 wherein the paddle means is arranged relative to the band so as to periodically remove at least a portion of the smoking material from successive zones of the band so as to profile the thickness of said layer of smoking material.

4. An apparatus as claimed in any preceding claim wherein the rotatable paddle means is provided by a paddle wheel.

5. An apparatus as claimed in any one of claims 1 to 3 wherein the rotatable paddle means is provided in use by a radially directed jet of fluid exiting from an apertured cylinder whose axis of rotation is said axis.

6. An apparatus as claimed in claim 5 wherein the fluid is air.

7. An apparatus for making a longitudinally profiled layer of smoking material on a moving conveyor band, substantially as hereinbefore described with reference to Figs. 1 and 2 or Figs. 3 to 5 of the accompanying drawings.