FR2527053A1 - FEEDING METHOD AND DEVICE FOR TOBACCO MACHINES - Google Patents

Abstract

THE INVENTION RELATES TO THE FORMATION AND TRANSPORT OF A LAYER OF TOBACCO 30, IN WHICH THE TOBACCO LEAVES OR STRIPS ARE ARRANGED HORIZONTALLY, ON A TRANSPORT SURFACE 32 WHICH IS ANIMATED BY VERTICAL VIBRATIONS. THE TOBACCO IS BROUGHT TO A CUTTING APPARATUS 12 WHERE IT IS DEBITED IN SCAFERLATI 28. TO IMPROVE ITS FORMATION AND ITS TRANSPORT ON CONVEYOR 34, THE LAYER OF TOBACCO 30 IS ANIMATED BY VIBRATIONS THE AMPLITUDE OF WHICH DECREASES IN THE SENSE OF LENGTH OF THE TRANSPORT SURFACE 32, SHAPED BY A BELT FOR EXAMPLE. TO THIS EFFECT, THE CONVEYOR 34 IS MOUNTED UP AND DOWN BY ROTATION AROUND A HORIZONTAL AXIS FIXED AT ITS EXIT END AND THE VIBRATION MECHANISM 60 ATTACK ITS OPPOSITE END OR FORM LAYER 30.

Description

The present invention relates to the supply of

tobacco choppers.

  A known type of tobacco chopper has a sup-

  rotary port for one or more knives which cut strips or strands of tobacco, for the manufacture of cigarettes, of the front face of a continuous mass of compacted tobacco, also called cake or load This load is formed and its content is compressed by a feeding device having an upper conveyor and a lower conveyor which define between them a passage whose height progressively decreases and which leads from a source of pieces

  of parenchyma called strips (from separation by bat-

  parenchyma and ribs of tobacco leaves) at a cutting station where the front face of the load is clamped between an upper pressing element and a lower pressing element, controlled by

  pneumatic cylinders, and enters the area of the rotary knives

  nants. French patent application 80/26,479, filed on December 12, 1980 in the name of the plaintiff, describes an improved method for supplying tobacco to the upper and lower feed and compression conveyors.

  first a layer of tobacco in which the tobacco is oriented essentially

  tially along the plane of the layer and in which the tobacco is entangled and distributed almost uniformly across the width of the layer Then the increase in the

  density of this layer and the entanglement of the leaves by the application

  cation of gravitational forces and vibration, during the

  transport of tobacco to the entry end of converging conveyors

  compression gents, without appreciably changing the orientation and the juxtaposition of the sheets or strips of tobacco in the layer The layer thus made denser is then transferred to the lower compression conveyor, also without this

  a noticeable change in orientation and juxtapo-

  sition of tobacco The orientation and the juxtaposition of tobacco are thus preserved throughout the course between the training point

  layer and the cutting device.

  This way of forming and transporting the tobacco load to the compression conveyors makes it possible to considerably reduce, compared to conventional systems, the compression required of the tobacco layer, for the same flow of tobacco, and to exert pressure significantly less on the tobacco load at the point where it is presented to the cutting device, to prevent the rotating knives from tearing strips from the load. The compression force affecting the filling capacity of the cut tobacco exerted by the conveyors may be less, the entanglement and the compression by gravity obtained according to

  said document preserve the filling power of cut tobacco.

  This power is also preserved more because tobacco

  is subjected to physical forces for less time than usual

study in the prior art.

  According to an embodiment of the method described in the aforementioned application, the compression conveyors are themselves 8

  fed by a substantially horizontal vibrating translation conveyor

  zontal A distribution of tobacco, in the form of whole sheets or strips, falling in the manner of a rain and uniformly on a longitudinal section of the conveyor, forms on the entry end of this vibrating conveyor a layer of tobacco relatively thick which contains the amount of tobacco needed for food

  of the cutting station, the thickness of this layer increasing progressively

  sively, in said section, in the longitudinal direction of movement of the conveyor The tobacco in this relatively thick layer is oriented essentially along the plane of the cauche

  and is distributed evenly across the width of the layer.

  The tobacco layer is vibrated on the conveyor

  due to the fact that the transport surface is moving in an alternating

  native in the vertical direction during the transport of the layer towards the compression conveyors The vibration increases the density of the layer of tobacco without the use of forces other than gravity and without noticeable change in orientation and juxtaposition

tobacco in the diaper.

  This orientation and this juxtaposition are also preserved when the layer is transferred from the vibrating conveyor to the lower compression conveyor. As there is no change in the speed of the tobacco over the entire path between the zone of formation of the layer and the Tobacco cutter does not have the possibility of changing its orientation and relative arrangement. This solution differs considerably from that described in US Pat. Nos. 4,244,382 and 4,254,781 and which uses a step conveyor which is vibrated in two directions. The step shape of this conveyor means that the speed of the pieces of tobacco-change abruptly to the right of the tier, where a thin starting layer forms a thick layer brought to the compression conveyors The thick layer is formed in this case by the pell-mell collapse of pieces of tobacco from the thin layer, to the right of the tier, * which changes the orientation and the juxtaposition of the pieces The conveyors described in these two patents are designed to transport sides, which support such handling According to the prior patent application cited by the applicant, the thick layer is made up of a distribution in the form of a rain of strips or whole leaves of tobacco,

  which retain their orientation and their juxtaposition or

  relative position on all the following course.

  The invention provides a method for producing tobacco strips or strands (scaferlati) by cutting a layer of compressed tobacco formed from whole tobacco leaves or pieces of parenchyma or strips, which are oriented essentially along the plane of the layer, tangled and spread evenly across the width of the layer, increasing the density of tobacco

  of the layer by application of gravitational forces and vibra-

  tion to it, during its essentially horizontal transport and without significant change in the orientation and the juxtaposition of the tobacco in the layer, as well as the compression of the tobacco made denser, which is characterized in that one reduces by uniformly, along its length, the vibration forces

  applied to the horizontally transported tobacco layer.

  Due to the decrease in the amplitude of the vertical vibrations to which the tobacco layer is subjected in

  the length direction of the transport surface, the maximum forces

  males are applied to tobacco when it is most needed, i.e. during the initial compaction and entanglement of tobacco, which is then subjected to decreasing forces as

  as it approaches its final state of compression.

  According to a preferred embodiment of the invention

  tion, the transport surface can be raised and lowered by rotation

  tion around a fixed horizontal axis at its outlet end,

  so that the vibration forces are zero at this end.

  The thick layer of tobacco is preferably formed, at the upstream end of the vibrating conveyor, by the uniform distribution of the tobacco in the form of a rain over a longitudinal section of the conveyor, so as to provide the layer of tobacco thus formed with '' an inclined rear face, from bottom to top in the direction of tobacco transport, and by supplying to the dispensing device a quantity of tobacco sufficient for the angle of this rear face or slope of the layer to be close of but does not exceed the natural angle of rest of the layer of tobacco, so that the pieces of tobacco are located flat and are oriented along the plane of the latter in the layer and do not roll over this embankment or do not fall from it despite

  the fact that the layer is brought to a thickness close to the thick-

  maximum achievable distance over the shortest possible length of the

transport surface.

  The speed of the upper and lower compression conveyors determines the speed of the layer along its entire course on said transport surface, up to the entry end of the

compression conveyors.

  According to a preferred embodiment of the invention

  tion, the tobacco layer on the transport surface is laterally confined by containment surfaces which are displaced in

  the direction of transport of the tobacco layer.

  In this embodiment, it is preferable that the containment surfaces and the transport surface give the tobacco a transport speed which is slightly higher than that of the convergent compression conveyors in order to ensure that the orientation and the juxtaposition of the tobacco in the layer are kept over the entire course from the formation zone of

  the layer up to the entry end of the converging conveyors.

  The invention also provides a device for implementing the process. This device, intended for production

  cut tobacco or scaferlati, includes top tobacco conveyors

  lower and lower which converge towards a downstream end, an apparatus

  cutting edge located near this end and intended for cutting the tobacco held at this end, as well as an essentially horizontal vibrating conveyor for transporting a layer of tobacco to the entry end of the passage formed between the converging conveyors and to apply alternative forces to this layer

  vertically during transport This device is essential

  characterized in that the vibrating conveyor is mounted re-

  can be lifted and lowered by rotation around a fixed horizontal axis at its outlet end, so that the amplitude of the vibrations decreases along the length of the conveyor This is generally oriented horizontally and has a surface of

mobile transport in translation.

  It is preferable that the device conferring the vibration on the conveyor is coupled to the upstream end thereof to produce rapid reciprocating movements of the conveyor in the vertical direction by rotation of the latter around the axis at its

downstream end.

  According to one embodiment, the transport surface has, in cross section, a substantially horizontal central portion which extends over a large part of the width of this surface and portions inclined downward between this central portion and the lateral edges. of the strap

  forming said transport surface.

  Other features and advantages of the invention

  tion will emerge more clearly from the description which follows

  of a nonlimiting exemplary embodiment, as well as of the appended drawings, in which: FIG. 1 is a schematic overall view of an exemplary embodiment of a device according to the invention;

252? 053

  Figure 2 is a perspective view of a

  vibrating feed conveyor in combination with a distributor

  tobacco killer, according to an embodiment of the invention; and Figure 3 is a cross section of the conveyor of Figure 2, taken along line 3-3 of this figure. The accompanying drawings illustrate the mode of implementation of the invention currently considered the best. They represent a tobacco chopper 10 with a cutting or chopping station 12 o an upper conveyor 14 and a lower conveyor 16 delimit a passage which decreases in height to an outlet end where an upper pressure plate 18 is located and

  a lower pressure plate 20 intended to exert a pressure

  sion on a mass of compressed tobacco 22 located between them The plates 18 and 20 present the mass or load of tobacco 22 to a rotary drum 24 whose surface carries knives 26 cutting

  tobacco strips or strands 28 of the load 22.

  The load 22 is formed of a thick layer of tobacco 30, which can be in the form of whole sheets or strips, which is formed on the vibrating transport surface 32 of a tobacco conveyor 34 of a uniform "rain" tobacco 36 falling uniformly in length and in width on a longitudinal section

  from the transport surface 32 to the upstream end thereof, that is

  ie opposite the cutting station 12 Details of the conveyor 34

  are shown in Figures 2 and 3.

  The distribution of tobacco 36 on a section of the transport surface 32 forms on this section a layer of tobacco in which the strips are arranged approximately horizontally and whose thickness corresponds to the flow of tobacco necessary for the cutting device 12 The tobacco rain 36 preferably has a flow such that the embankment 37 at the rear of the formed tobacco layer 30 has an angle close to but not exceeding the natural rest angle of the tobacco layer. tobacco does not fall out

  backwards, which would change their orientation and

relative sition.

  The vertical vibrations applied to the transport surface 32 produce the entanglement and the compaction of the pieces of tobacco but do not modify their relative arrangement and their orientation. The vibration forces of the conveyor 34 and gravity are the only forces applied to the tobacco * for give it back

  denser As the conveyor 34 is mounted oscillating at its end

  downstream, the amplitude of the vibrations, according to the invention, decreases uniformly from a maximum value at the end

  upstream to zero at the downstream end In this way, the vi-

  brations have the greatest amplitude during the start of the tobacco layer formation and decrease in amplitude as

let the layer settle.

  The mobile surface 32 carries the thick layer of

  tobacco 30 up to the entrance of the passage formed by the conveyors

  gents 14 and 16, where layer 30 is transferred to the lower conveyor

  laughing 16 The layer 30 is transported at constant speed over the entire route from its formation at the upstream end of the transport surface 32 to the exit of the passage between the conveyors 14 and 16 The initial horizontal orientation of the pieces of tobacco and their relative arrangement in the thick layer 30 are thus preserved

  up to the point where the tobacco mass 22 is cut into scaferlati.

  The speed of advance of the layer 30 is determined by the speed of transport of the converging conveyors 14 and 16 To ensure that the tobacco of the layer 30 retains its orientation and its juxtaposition, the transport speed of the surface 32 is preferably slightly greater than that of the conveyors 14 and 16, so that a slip

  is established between the surface 32 and the tobacco layer 30.

  This procedure makes it possible to considerably reduce-

  the pressure to be exerted on the gfteau 22 to prevent tearing

  of strips, compared to the conventional technique and for the same flow of tobacco According to a typical example, the pressure

  of air for the pneumatic cylinders controlling the pressure plates

  sion 18 and 20 can be reduced from approximately 2.8 to approximately 0.35 bar.

  It was found that the scaferlati 28 thus obtained has a better

their filling power.

  Figures 2 and 3 show that the conveyor 34 has a continuous conveyor belt 32 which circulates around rollers

  horizontal 38 and 40 mounted between side members 42 and 44 These

  niers are mounted oscillating, at the outlet end of the conveyor 34,

  on fixed parts of the cutting station frame 12.

  The belt 32 is shaped by its passage over

  supports (not shown) so as to define, in cross section

  dirty, two portions 46 and 48 inclined downward and situated on either side of a horizontal central portion 50 This configuration of the belt 32, which is most clearly shown in FIG. 3, produces a more even distribution tobacco across the width of the compacted mass 22, compared to

prior art.

  At the opposite end of the axis of oscillation, the longitudinal members 42 and 44 are mounted on compression springs 52 and 54 arranged on a support table 56 A spacer 58 fixed transversely between the longitudinal members 42 and 44 is connected by a connecting rod 60 to a crankshaft 62 which an engine 64 rotates by

  via a belt 66 passing over pulleys 68 and 70.

  When the engine 64 turns the crankshaft 62, the connecting rod 60 makes the side members 42 and 44 go up and down and

  with them the conveyor belt 32 The springs 54 serve as shock absorbers

  weavers for the vibrations thus applied by the connecting rod 60 La

  tobacco layer 30 on the belt 32 is thus subjected to vibrations

  continuous states whose amplitude decreases uniformly as

as the tobacco layer advances.

  The conveyor 34 shown by way of example in FIGS. 2 and 3 further comprises two upper beams 72 and 74 2.5 located above the lower beams 42 and 44 and connected to them The upper beams 72 and 74 are connected between them by cross members 76 and 78 Two conveyor belts 80 and 82, between the side members 42 and 72 on the one hand and between the side members 44 and 74 on the other hand, circulate around rollers 84 and 86 (shown

  only for the conveyor belt 80).

  Belts 80 and 82 retain the tobacco layer 30

  on both sides and are driven at the same speed as the run

  line 32, by a drive mechanism 88 shown schematically-

  The movable side belts 80 and 82 ensure that the tobacco strips of layer 30 retain their orientation and their relative arrangement and do not tend to catch on, as could be the case with fixed side walls, which could

  disturb or undo the arrangement of tobacco in layer 30.

  The tobacco rain 36, falling uniformly in the transverse direction and in the longitudinal direction on the conveyor 34,

  is produced in this example by a tobacco distributor 90.

  This includes a feed belt 92 on which strips or tobacco leaves 94 are transported to a point

  located above the upstream end of the conveyor belt 32.

  A leaf plate 96 is suspended oscillating near the former

  exit end of the feed belt 92 and can be driven by reciprocating movements of advancement and retraction by a drive mechanism 98 The leaf 96 comes into contact with the strips 94 during their fall from the end of the belt 92

  and its reciprocating movement forms the rain of tobacco 36.

  Although the feed belt 92 of the example shown is oriented lengthwise of the conveyor 34,

  the same result can be obtained by placing this perpen- ted belt

  specifically to the conveyor 34, which would correspond to a supply

cross section of tobacco 94.

  The conveyor 34 therefore allows the formation of the tobacco layer 30 and its transport to the cutting device 12 Les

  30 layer tobacco sheets or strips are arranged essential-

  flat, they are compacted during transport by the cour-

  lines 32, 80 and 82 and they keep their orientation and their

  relative starting position during this transport.

  The invention is not limited to the embodiments described and those skilled in the art may make various modifications thereto,

  without going beyond its framework.

1 O

Claims (3)

  1 Process for producing tobacco strips or strands (scaferlati) by cutting a layer of compressed tobacco formed from whole tobacco leaves or pieces of parenchyma or strips, which are oriented essentially along the plane of the layer, entangled and distributed uniformly over the width of the layer, the increase in the density of the tobacco of the layer by application of gravitational forces and vibration to the latter, during its essentially horizontal transport and without significant change in orientation and juxtaposition of the tobacco in the layer, as well as the compression of the tobacco made denser, characterized in that one uniformly reduces, in the direction of its length, the vibration forces applied to the layer of tobacco transported horizontally. 2 Method according to claim 1, characterized in that   the tobacco layer is formed from strips or tobacco leaves tom-   bant like a rain from a tobacco dispenser and so   that the tobacco layer thus formed has a face or embankment   rière whose angle is close to the natural angle of rest of the layer, but without exceeding it.   3 Device - for producing tobacco strips or strands   (scaferlati), for implementing the method according to the claim   tion 1 or 2, comprising an upper tobacco conveyor and a converging lower tobacco conveyor which define them   a passage narrowing towards an outlet end, a device   cutting tif located near this end and intended to cut the tobacco maintained at this end, as well as an essentially horizontal vibrating conveyor for transporting a layer of tobacco to the entry end of said passage between the converging conveyors and to apply to this layer of tobacco, during its transport on it, alternative forces in the vertical direction, characterized in that the vibrating conveyor (34) is mounted to be raised and lowered by rotation about an axis (38) X its end output, so that the amplitude of the vibrations decreases in the direction the length of the conveyor (34).   4 Device according to claim 3, characterized in that the device (60) applying the vibrations is coupled to the upstream end of the vibrating conveyor (34) and confers thereon   rapid alternating movements in the vertical direction by rotation   tion around the axis (38). Device according to claim 3 or 4, characterized   in that the conveyor 34) is arranged at least about horizontally-   and has a transport surface, notably constituted   by a conveyor belt (32), which is movable in translation.   6 Device according to any one of claims   3 to 5, characterized in that the transport surface (32) has, in cross section, a central portion (50) essentially horizontal and extending over a large part of the width of this surface, as well as portions (46 , 48) inclined downwards which extend from the central portion (50) to   lateral edges of the transport surface (32).