GB2120919A

GB2120919A - Feeding tobacco cutting machine

Info

Publication number: GB2120919A
Application number: GB08220715A
Authority: GB
Inventors: Warren Arthur Brackmann; Stanislav Minoslav Snaidr
Original assignee: ROTHMANS OF PALL MALL; Rothmans of Pall Mall Canada Ltd
Current assignee: ROTHMANS OF PALL MALL; Rothmans Benson and Hedges Inc
Priority date: 1982-05-21
Filing date: 1982-07-16
Publication date: 1983-12-14
Also published as: FR2527054A1; ZA825111B; SE8206569D0; NL8203798A; IT8319021A0; FR2527052B1; SE452706B; JPS6151862B2; IT1205615B; DE3300152A1; FR2527053A1; NL182615C; SE8206569L; IT1167352B; AU554775B2; AU8872982A; ZA828434B; DE3231464A1; FR2527053B1; SE8205497L

Abstract

The transportation of a tobacco layer, in which the tobacco lamina or leaves (94) are horizontally oriented, on a vertically-reciprocating conveyor surface (32) to a cutting machine (12), wherein tobacco shreds are formed from the tobacco (94) in the layer, is assisted by moving side wall conveyors (80,82) so that the orientation and juxtaposition of the tobacco (94) in the layer is maintained to the cutting machine (12). The layer is densified by vibrational and gravitational forces. It is compacted by passing it between upper and lower conveyors (14,16). <IMAGE>

Description

GB 2 120 919 A 1

SPECIFICATION

Feeding tobacco cutting machine - I The present invention is directed to the feed of 70 tobacco to cutting machines.

A known type of tobacco shredding apparatus comprises a rotary carrier for one or more knives which cut tobacco shreds, for use in making cigaret tes, from the leading face of a continuous mass of compacted tobacco. The compacted mass is formed and the tobacco therein provided in compacted form by a feeding device comprising a pair of upper and lower feed conveyors which define a gradually 15 narrowing or converging path extending from a source of threshed tobacco lamina to a comminuting station where the leading face of the compacted mass is squeezed between air cylinder pressure assisted upper and lower pressure applying ele 20 ments and moves into the range of the orbiting knives.

In our prior U.K. patent application No 8039589 (Serial No. 2066046) filed 1 Oth December 1980, there is described an improved procedure for feeding tobacco to the compacting pair of upper and lower feed conveyors. As set forth therein, a layer of tobacco first is formed wherein the tobacco is oriented substantially planarly of the layer, the tobacco is interleaved and the tobacco is substantial 30 ly uniformly distributed acress the layer. The tobac co layer then is densified and the leaves nested by applying gravitational and vibrational forces thereto while simultaneously conveying the tobacco to wards the upstream end of the converging con 35 veyors without substantially altering the orientation and juxtaposition of the tobacco in the layer. The densified layer then is fed onto the lower one of the converging conveyors without substantially altering the orientation and juxtaposition of the tobacco in 40 the densified layer. In this way, the orientation and juxtaposition of the tobacco is maintained all the way from the initial formation of the layer to the cutters.

The formation and conveying of the tobacco in this 45 manner to the compacting conveyors results in much less compaction being required to be effected on the tobacco layer for the same throughput of tobacco when compared with conventional systems, and much less pressure needs to be applied to the 50 compacted tobacco presented to the cutter to pre vent lamina pull-outs, when compared with conven tional procedures.

Since less compacting force needs to be applied to the lamina by the conveyors and such compacting 55 force impares the filling power of the cut tobacco, 120 the gravity-induced precompaction and nesting which is effected in this invention preserves the filling power of the cut tobacco. In addition, since the gravity-compacted tobacco is subjected to physical 60 force for a lesser period of time than is usual in the prior art, more of the filling power is preserved.

In one embodiment of the procedure described in our prior application, a vibrating translating con veyor is provided which extends substantially hori zontally away from the upstream end of the com- pacting conveyors. A relatively thick layer of tobacco containing the quantity of tobacco desired to be fed to the cutting station is formed at the upstream end of the conveyor by showering tobacco, in the form of whole leaves or threshed lamina, uniformly over a length of the conveyor, so that the tobacco builds up to the required layer thickness in the longitudinal direction of movement of the conveyor. The tobacco in the relatively thick layer is oriented substantially 75 planarly of the layer and is substantially evenly distributed across the width of the layer.

The tobacco layer is subjected to vibration on the conveyor by vertical reciprocation of the conveying surface as the layer is conveyed thereon by the 80 conveyor towards to the compacting conveyors under the influence of the translating surface of the conveyor. The vibration causes the tobacco in the layer to densify without the use of any force other than gravity while.the layer is transported by the 85 translating conveyor towards the cutting station without substantially altering the orientation and juxtaposition of the tobacco in the layer.

This orientation and juxtaposition is maintained as the layer is transferred from the vibrating conveyor 90 to the lower one of the converging conveyors.There is no change in speed of the tobacco from the initial formation of the tobacco layer all the way to the cutters, and hence there is no opportunity for the tobacco to change its orientation and juxtaposition.

This operation contrasts markedly with that set forth in U.S. Patents Nos. 4,244,382 and 4,254,781, both to Thiele et al, wherein a stepped conveyor is used and the stepped conveyor is vibrated in two directions. The stepped form of the conveyor means 100 that the speed of the tobacco particles abruptly changes as an initially-formed thin layer forms a thick layer at the step in the conveyor for feed to the compacting conveyors. In this prior art, the thick layer of tobacco particles required to be fed to the

105 cutters is formed by tumbling of particles from the thin stream at the step to form the thick layer, thereby altering the orientation and juxtaposition of the particles. The conveyors set forth in this prior art are designed to handle stem material, wherein such

110 manipulation may be tolerated. In the procedure of our prior application, a thick layer is formed from a shower of tobacco lamina or whole leaves wherein the tobacco particles are provided in their final orientation and juxtaposition.

The present invention is concerned with improvements in the procedure of our prior application to improve the operation thereof. In the present invention, the translational vibrating conveyor is provided with side walls which engage the sides of the tobacco layer and which have translational motion at the same speed as the translational motion of the vibrating conveyor.

Accordingly, the present invention provides a method of forming cut tobacco shreds, which com- 125 prises (a) forming a layer of tobacco in whole leaf or threshed lamina form on a conveying surface, the tobacco in the layer being oriented substantially planarly of the layer, being interleaved and being substantially uniformly distributed across the layer; 130 (b) clensifying the tobacco layer by applying gravita- 2 GB 2 120 919 A tional and vibrational forces only thereto while simultaneously conveying the tobacco towards the downstream end of the conveying surface without substantially altering the orientation and juxtaposi tion of the tobacco in the layer; (c) confining the tobacco layer on the conveying surface at the sides thereof by confining surface and moving the confin ing surfaces in the direction of movement of the tobacco layer; (d) feeding the densified layer onto the lower one of a pair of upper and lower converging conveying surfaces without substantially altering the orientation and juxtaposition of the tobacco in the densified layer; (e) compacting the fed tobacco layer between the converging upper and lower conveying surfaces while conveying the same towards the downstream end of the upper and lower converging conveying surfaces; and (f) cutting tobacco shreds from the forward end of the compacted tobacco at the downstream end of the converging conveying surfaces.

The provision of the moving side walls in association with the vibrating conveyor avoids any tendency of the tobacco to be held by a stationary side wall, and thereby to alter the orientation and/or juxtaposi- tion of the tobacco.

In a preferred embodiment of the invention, the conveying surface forthe tobacco layer extends substantially horizontally to the upstream end of the converging conveying surfaces, the tobacco layer is formed at the upstream end of the conveying surface, and the conveying surface moves rectilinearly from its upstream end to its downstream end. The formation of the tobacco layer atthe upstream end of the conveying surface may be 35 effected by showering tobacco downwardly towards 100 the upstream end of the conveying surface and deflecting tobacco in the shower to fall uniformly over a length of the conveying surface. The com bined effect of the uniform showering of the tobacco and the rectilinear conveying of the tobacco layer on 105 the conveying surface produces a tobacco layer having an upwardly-inclined rear surface extending in the direction of movement of the layer.

Preferably, the tobacco is fed to the shower in suff icient quantity thatthe angle of the upwardlyinclined rear surface of the tobacco layer approximates but does not exceed the angle of repose of the layer, so that the showered and distributed tobacco lies planarly in the layer and does not fall or tumble from the rear surface of the layer. In this way, the thickness of the tobacco layer approximates the maximum attainable in the shortest length of conveyor surface.

The tobacco is usually gripped at the downstream end of the converging conveying surfaces during the 120 cutting of tobacco shreds from the forward end of the compacted tobacco layer. The speed of movement of the upper and lower converging conveyors determines the speed of the tobacco layer all the way from formation thereof on the conveying surface to the downstream end of the upper and lower converging conveying surfaces. Preferably, the confining surfaces and conveying surface move at a slightly greater conveying speed than that of the converging conveying surfaces to ensure that the orientation and juxtaposition of tobacco in the layer is maintained all the way from formation of the tobacco layer to the downstream end of the converging conveyors.

The vibrational forces, which are applied to the tobacco layer on the conveying surface, may decrease in a uniform manner from a maximum value at the upstream end of the conveying surface to a minimum value at the downstream end of the 75 conveying surface. In this way, the tobacco is subjected to the greatest forces when most needed, that is, during the initial compaction and nesting of the tobacco, and is subjected to a diminishing force as the tobacco compacts to a finely-compacted state.

80 This may be achieved by mounting the conveying surface for pivoting about a horizontal ly-extending pivot located at its downstream end and vertically reciprocally moving the upstream end of the conveying surface so that it moves about the pivot.

The present invention also includes apparatus for carrying out the method of the invention. In accordance with the present invention, therefore, there is also provided an apparatus for forming cut tobacco, which comprises (a) upper and lower tobacco con- 90 veyors converging towards a downstream end thereof, (b) cutting means located adjacent the downstream end of the converging conveyors for cutting tobacco held at the downstream end, (c) a generally horizontal ly- extending vibrating conveyor 95 for conveying a layer of tobacco to the upstream end of the conveying conveyors and for applying vertically-reciprocating vibrating forces thereto while conveying the tobacco layerthereon, and (d) confining movable side walls located at each side of the vibrating conveyor to engage the side edges of the tobacco layer.

In the apparatus of the invention, the confining movable side walls preferably comprise verticallyextending conveyor belts extending one each side of and for substantially the length of the vibrating conveyor and rotatable rollers on which the conveyor belts are mounted. Preferably, the verticallyextending conveyor belts are mounted in fixed position relative to the vibrating conveyor for recip- 110 rocating vertical movement therewith.

The vibrating conveyor preferably extends substantially horizontally with the tobacco conveying surface capable of rectilinear motion. The conveying surface usually is constituted by a continuous con- 115 veyor belt. Preferably, the conveying surface is pivotally mounted at its downstream end to a horizontally-extending pivot, so that the verticallyreciprocating vibrating forces decrease uniformly along the length of the vibrating conveyor from a maximum at the upstream end of the vibrating conveyor to zero at the downstream end of the vibrating conveyor.

In one construction, the conveying surface, in cross section has a generally planar central portion 125 extending for a substantial proportion of the width and has downwardly-sloping portions extending from the planar portions to the side edges of the conveyor belt.

In one preferred embodiment of the invention, the 130 vibrating conveyor and the confining movable side f r GB 2 120 919 A 3 wall comprise a plurality of elements. In this embodi ment, a horizontally-extending frame is mounted at one longitudinal end thereof for pivoted movement adjacent the upstream end of the converging con veyors about an axis extending generally horizontal ly transverse to the longitudinal axis of the vibrating conveyor. A first conveyor belt is mounted to the frame and extends horizontally therein for transport ing the layer of tobacco thereon from adjacent the 10 other longitudinal end of the frame to the one longitudinal end of theframe. Second and third conveyor belts are mounted to the frame and extend vertically therein one on each side of the first conveyor for engaging the side edges of the layer of tobacco as it is transported on the first conveyor belt. 80 Drive means is provided for driving the tobacco engaging surfaces of the conveyor belts towards the pivotal end of the frame at substantially the same speed, so that the orientation and juxtaposition of tobacco in the layer is substantially unaltered during conveying by the first conveyor belt. Vibration inducing means is connected to the other longitudin al end of the frame for effecting rapid vertically reciprocal movement of the frame thereby to impart the vibration to the first conveyor belt and to the tobacco layer thereon. The frame may be sprung adjacent the other longitudinal end thereof to dam pen the vibrations. The respective side edges of the first conveyor belt may engage the second and third conveyor belts adjacent the lower edges thereof.

The apparatus of the invention preferably includes a tobacco feed device for forming a failing shower of tobacco, in whole leaf or shredded lamina form which extends uniformly over a predetermined 35 longitudinal distance of the vibrating conveyor, whereby the tobacco layer is built up over the predetermined conveyor length. The tobacco feed device may comprise a conveyor belt located above the upstream end of the conveyor belt which permits tobacco to fall from the end thereof and a distributor device which distributes the failing tobacco into a shower which contains a uniform quantity of tobac co in the length and width thereof.

The invention is described further, by way of 45 illustration, with reference to the accompanying 110 drawings, wherein:

Figure 1 is an overall schematic representation of one embodiment of apparatus provided in accordance with this invention; Figure 2 is a perspective view of an apparatus for feeding tobacco to a cutting machine, constructed in accordance with one embodiment of the invention; and Figure 3 is a sectional view of the conveyor of Figure 2, taken on line 3-3 of Figure 2.

Referring to the drawings, which illustrate the current best mode known to the applicant for effecting the invention, a tobacco cutting apparatus 10 comprises a cutting station 12 wherein upper and 60 lower conveyors 14 and 16 converge towards a 125 downstream throat at which is located a pair of upper and lower pressure plates 18 and 20 mounted to apply pressure to a compacted tobacco mass 22 located therebetween. A rotating drum carrier 24 has a plurality of cutting knives 26 peripherally mounted 130 for cutting shreds of tobacco 28 from the cake 22.

A thick layer 30 of tobacco, which may be in whole leaf or threshed lamina form, is formed on the vibrating conveying surface 32 of a tobacco conveyor 34 from a uniform shower 36 of tobacco which is distributed over a length of the conveying surface 32 at the upstream end thereof, remote from the cutting station 12, and substantially uniformly across the width. The details of construction of the tobacco 75 conveyor 34 are shown in Figures 2 and 3.

By distributing the tobacco from the shower 36 over a length of the conveying surface 32, the tobacco is allowed to build up to the required thickness over that length of the conveying surface 32 with the lamina strips lying substantially horizontally, the thickness corresponding to the feed required by the cutting machine 12 at the desired throughput of tobacco. The tobacco is preferably fed to the shower 36 in such quantity as to provide the 85 upwardly-angled rear face 37 of the tobacco layer 30 approximating but not exceeding the angle of repose of the layer. In this way, the tobacco particles do not fall or tumble rearwardly and alter their orientation and juxtaposition.

The vertically-reciprocating vibrations of the conveying surface 32 cause the tobacco to nest and compact while retaining their juxtaposition one to another and their orientation. The vibrational forces of the conveyor 32 and the force of gravity are the 95 only forces applied to the tobacco which cause compaction. Since the conveyor 32 is pivoted at its downstream end, as discussed in more detail below, the magnitude of the vibrations diminish uniformly from the maximum value at the upstream end to 100 zero and the downstream end. In this way, the vibrations diminish as the tobacco layer assumes its compacted form.

The moving surface 32 conveys the thick layer 30 of tobacco to the mouth of the conveyors 14 and 16, 105 whereat the thick layer 30 is transferred to the lower conveyor 16. The layer 30 is conveyed at a constant speed all the way from its formation at the upstream end of the conveying surface 32 to the throat between the downstream end of the conveyors 14 and 16. In this way, the initial horizontal orientation of the tobacco lamina and juxtaposition thereof within the thick layer 30 is maintained to the cutting of the tobacco mass 22. The speed of movement of the thick layer 30 is determined by the conveying 115 speed of the converging conveyors 14 and 16. To ensure that the tobacco in the thick layer 30 retains its orientation and juxtaposition, the surface 30 is preferably run at a conveying speed which is slightly greater than that of the converging conveyors 14 and 120 16 to cause slipping between the surface 32 and the layer30.

This procedure enables the pressure that needs to be applied to the cake 22 to prevent lamina pull out to be significantly decreased for the same throughput of tobacco, as compared with the conventional process. Typically, the air cylinder pressure which needs to be applied can be decreased from about 275 kPa to about 35 kPa. An improved filling power of the tobacco shreds 28 resulting from the cutting has been observed.

4 GB 2 120 919 A Turning now to consideration of Figures 2 and 3, details of the construction of the conveyor 34 are illustrated therein. The conveyor 34 has a continuous conveyor belt 32 which is mounted about horizontal 5 ly-extending rollers 38 and 40 which are mounted to side frame members 42 and 44. The frame members 42 and 44 are pivoted at the downstream end of the conveyor 34 to fixed frame members of cutting station 12.

10 The conveyor belt 32 is shaped over support 75 members (not shown) to have, when viewed in cross section, downwardly sloping portions 46 and 48 extending at each side of a central planar portion 50.

This construction is most clearly seen in Figure 3.

The shaping of the conveyor belt 32 provides a more even distribution of tobacco across the width of the compacted mass 22 than is the case in the prior art.

The frame members 42 and 44 are supported at the end remote from the pivot by compression 20 spring supports 52 and 54 respectively, which are mounted to a support table 56. A cross brace frame member 58 extends between and is affixed the frame members 42 and 44. A crank arm 60 is pivotally connected to the cross-brace frame mem ber 58 and is mounted to an axle 62 to be eccentrical ly rotated with respect to the axle 62. The axle 62 is driven by motor 64 through belt 66 trained around pulleys 68 and 70.

As the motor 64 drives the axle 62, the crank arm 30 60 moves eccentrically about the axle 62, thereby raising and lowering the frame members 42 and 44 and hence the conveyor belt 32. The springs 54 cushion the vibrations induced by the movement of the crank arm 60. The motor 64 is run at such a speed 35 as to subjecttobacco layer 30 on the surface of the conveyor belt 32 to continuous vibrations of uni formly-diminishing magnitude as the layer 30 is transported by the conveyor belt 32.

Spaced from and joined to the lower frame 40 members 42 and 44 are upper frame members 72 and 74 joined by cross members 76 and 78. Con veyor belts 80 and 82 are mounted between the respective pairs of frame members 42 and 72 and 44 and 74 on rollers 84 and 86, only the two for the 45 conveyor belt 80 being shown.

The conveyors 80 and 82 engage the sides of the tobacco layer 30 and are driven at the same speed as the conveyor belt 32 through a suitable drive mechanism shown schematically at 88. The provi 50 sion of the moving side belts 80 and 82 engaging the tobacco layer 30 ensures that the tobacco lamina in the layer 30 maintain their orientation and relative juxtaposition and have no tendency to hang-up on stationary confining walls of the conveyor, which 55 may lead to disruption of the tobacco layer and loss of orientation and juxtaposition.

A tobacco feed mechanism 90 is provided to form the tobacco shower 36 containing a uniform distribu tion of tobacco both transversely and longitudinally 60 of the conveyor 34. The tobacco feed mechanism 90 comprises a feed belt 92 on which threshed tobacco lamina or tobacco leaves 94 are transported to a location above the upstream end of the conveyor belt 32. A plate 96 is hingedly attached adjacent the downstream end of conveyor belt 92 for to-and-fro movement under the influence of drive mechanism 98. The plate 96 engages the tobacco lamina 94 as it falls from the end of the conveyor 92 and its to-and-fro movement causes the shower 36 of 70 tobacco to be formed.

Although the feed belt 92 is illustrated as extending coaxially with the conveyor 34, the same result can be achieved by arranging the feed belt 92 perpendicularly to the conveyor 34, so that the tobacco 94 is fed from the side to the conveyor 34.

The tobacco conveyor 34, therefore, enables a tobacco layer 30 to be formed and transported to the cutting mechanism 14. The tobacco in the layer 30 is oriented substantially planarly, is densified as it is 80 transported by the belts 32, 80 and 82 and maintains its orientation and juxtaposition as it is transported.

In summary of this disclosure, the present invention provides an improved procedure for forming and transporting a tobacco layer to a cutting

85 machine. Modifications are possible within the scope of this invention.

Claims

1. A method of forming cut tobacco shreds, which comprises (a) forming a layer of tobacco in whole leaf or threshed lamina form on a conveying surface, the tobacco in the layer being oriented substantially planarly of the layer, being interleaved 95 and being substantially uniformly distributed across the layer; (b) densifying the tobacco layer by applying gravitational and vibrational forces only thereto while simultaneously conveying the tobacco towards the downstream end of the conveying 100 surface without substantially altering the orientation and juxtaposition of the tobacco in the layer; (c) confining the tobacco layer on the conveying surface at the sides thereof by confining surface and moving the confining surfaces in the direction of movement 105 of the tobacco layer; (d) feeding the densified layer onto the lower one of a pair of upper and lower converging conveying surfaces without substantially altering the orientation and juxtaposition of the tobacco in the densified layer; (e) compacting the 110 fed tobacco layer between the converging upper and lower conveying surfaces while conveying the same towards the downstream end of the upper and lower converging conveying surfaces; and (f) cutting tobacco shreds from the forward end of the com- 115 pacted tobacco at the downstream end of the converging conveying surfaces.

2. A method as claimed in claim 1, in which the conveying surface extends substantially horizontally to the upstream end of the converging conveying 120 surfaces, the tobacco layer is formed at the upstream end of the conveying surface and the conveying surface moves rectilinearly from its upstream end to its downstream end.

3. A method as claimed in claim 2, in which the 125 formation of the tobacco layer at the upstream end of the conveying surface is effected by showering tobacco downwardly towards the upstream end of the conveying surface and deflecting tobacco in the showerto fall uniformly over a length of the 130 conveying surface, whereby the layer is built up over C 6 i GB 2 120 919 A 5 the length of conveying surface and has an upwardly-inclined rear surface.

4. A method as claimed in claim 3, in which tobacco is fed to the shower in sufficient quantity that the angle of the upwardly-inclined rear surface approximates but does not exceed the angle of repose of the layer, whereby the showered and distributed tobacco lies planarly in the layer and does not fall or tumble from the rear surface of the 10 layer.

5. A method asclaimed in anyone of claims 1 to 4 in which the tobacco is gripped at the downstream end of the converging conveying surfaces during the cutting of tobacco shreds from the forward end of the compacted tobacco layer.

6. A method as claimed in any one of claims 1 to 5, in which the speed of movement of the upper and lower converging conveyors determines the speed of the tobacco layer all the way from formation thereof on the conveying surface to the downstream end of the upper and lower converging conveying surfaces, and the confining surfaces and conveying surfaces move at a slightly greater conveying speed than that of the converging conveying surfaces to 25 ensure that the orientation and juxtaposition of tobacco in the layer is maintained all the way from formation of the layer to the downstream end of the converging conveyors.

7. A method asclaimed in anyone of claims 1 to 6, in which the vibrational forces applied to the tobacco layer on the conveying surface decrease in a unform manner from a maximum value atthe upstream end of the conveying surface to a minimum value at the downstream end of the conveying 35 surface.

8. A method of forming cut tobacco substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

9. An apparatus for forming cut tobacco, which 40 comprises (a) upper and lower tobacco conveyors converging towards a downstream end thereof, (b) cutting means located adjacent the downstream end of the converging conveyors for cutting tobacco held at the downstream end, (c) a generally horizontal ly- 45 extending vibrating conveyor for conveying a layer of tobacco to the upstream end of the conveying conveyors and for applying vertical ly- reciprocating vibrating forces thereto while conveying the tobacco layer thereon, and (d) confining movable side walls located at each side of the vibrating conveyor to 115 engage the side edges of the tobacco layer.

10. An apparatus as claimed in claim 9, in which the confining movable side walls comprise vertically-extending conveyor belts extending one each side 55 of and for substantially the length of the vibrating conveyor and rotatable rollers on which the conveyor belts are mounted.

11. An apparatus as claimed in claim 10, in which the verticallyextending conveyor belts are mounted 60 in fixed position relative to the vibrating conveyor for reciprocating vertical movement therewith.

12. An apparatus as claimed in anyone of claims 9 to 11, in which the vibrating conveyor extends substantially horizontally and the tobacco conveying surface is capable of rectilinear motion.

13. An apparatus as claimed in claim 12, in which the tobacco conveying surface is constituted by a continuous conveyor belt.

14. An apparatus as claimed in anyone of claims 70 9 to 13, in which the conveying surface is pivotally mounted at its downstream end to a horizontallyextending pivot, whereby the verticallyreciprocating vibrating forces decrease uniformly along the length of the vibrating conveyor from a maximum at the upstream end of the vibrating conveyor to zero at the downstream end of the vibrating conveyor.

15. An apparatus as claimed in anyone of claims 9 to 14, in which the conveying surface, in cross 80 section, has a generally planar central portion extending for a substantial proportion of the width and has downwardly-sloping portions extending from the planar portion to the side edges of the conveyor belt.

16. An apparatus as claimed in claim 9, in which the vibrating conveyor and the confining movable side walls comprise (a) a horizontallyextending frame mounted at one longitudinal end thereof for pivotal movement adjacent the upstream end of the 90 converging conveyors about an axis extending generally horizontally transverse to the longitudinal axis of the vibrating conveyor, (b) a first conveyor belt mounted to the frame and extending horizontally therein for transporting the layer of tobacco thereon 95 from adjacent the other longitudinal end of the frame to the one longitudinal end of the frame, (c) second and third conveyor belts mounted to the frame and extending vertically therein one on each side of the first conveyor for engaging the side edges 100 of the layer of tobacco as it is transported by the first conveyor belt, (d) drive means for driving the tobacco engaging surfaces of the conveyor belts towards the pivoted end of the frame at substantially the same speed, so that the orientation and juxtapo- 105 sition of tobacco in the layer is substantially unaltered during conveying by the first conveyor belt, and (e) vibration inducing means connected to the other longitudinal end of the frame for effecting rapid vertical ly-reciprocal movement of the frame 110 thereby to impart the vibration to the first conveyor belt and to the tobacco layer thereon.

17. An apparatus as claimed in claim 16, in which the frame is sprung adjacent the other longitudinal end thereof to dampen the vibrations.

18. An apparatus as claimed in claim 16 or 17, in which the respective side edges of the first conveyor belt engage the second and third conveyor belts adjacent the lower edges thereof.

19. An apparatus as claimed in any one of claims 120 9 to 18, including a tobacco feed device for forming a falling shower of tobacco in whole leaf or threshed lamina form which extends uniformly over a predetermined longitudinal distance of the vibrating conveyor, whereby the tobacco layer is built up over the 125 predetermined conveyor length.

20. An apparatus as claimed in claim 19, in which the tobacco feed device comprises a conveyor belt located above the upstream end of the conveyor belt which permits tobacco to fall from the end thereof 130 and a distributor device which distributes the failing 6 GB 2 120 919 A 6 tobacco into a shower which contains a uniform quantity of tobacco in the length and width thereof.

21. An apparatus for forming cut tobacco substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon, Surrey, 1983. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.

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