Title:
FEEDING DEVICE FOR TANGLED TOBACCO FRAGMENTS OR STANDARD CUT-LEAF TOBACCO
United States Patent 3586211


Abstract:
A device for constituting substantially constant volumetric doses from a mass of material composed of tangled fragments, comprising a chamber having an inlet and an outlet, means for supplying material to said chamber and connected to said inlet, means for retaining the material at said inlet, and movable means for closing off said outlet.



Inventors:
BONNERIC FRANCIS
Application Number:
04/811298
Publication Date:
06/22/1971
Filing Date:
03/28/1969
Assignee:
SERVICE D'EXPLOITATION INDUSTRIELLE DES TABACS ET DES ALLUMETTES
Primary Class:
Other Classes:
131/108, 198/570, 222/280
International Classes:
B65B1/36; (IPC1-7): B67D5/08; B67D5/12
Field of Search:
222/56,127,55,77,280 221
View Patent Images:



Primary Examiner:
Bockenek, David M.
Claims:
What I claim is

1. A device for portioning out substantially constant volumetric doses from a mass of material composed of tangled fragments, said device comprising a chamber having an inlet and an outlet, means for supplying material to said chamber, said means being connected to said inlet, means for retaining said material at said inlet, and movable means for closing off said outlet, said chamber having a volume at least corresponding to that of said doses, said chamber disposed for serving as a dosing compartment.

2. A device for portioning out substantially constant volumetric doses from a mass of material composed of tangled fragments, said device comprising a chamber having an inlet and an outlet, means for supplying said material to said chamber, said means being connected to said inlet, means for retaining said material at said inlet, movable means for closing off said outlet, said means for retaining said material comprising at least one needle movable transversely to the direction of flow of said material.

3. A device according to claim 2, wherein said means for retaining material comprises at least two needles forming a retractable fork.

4. A device for portioning out substantially constant volumetric doses from a mass of material composed of tangled fragments, said device comprising a chamber having an inlet and an outlet, said outlet having a wall, means for supplying said material to said chamber, said means being connected to said inlet, means for retaining said material at said inlet and movable means for closing off said outlet, said movable means comprising a blade wheel, and a space being provided between said wall of said outlet and the surface being swept by the tips of said blades of said wheel, said wall being deformable.

5. A device in accordance with claim 1, wherein said means for supplying the chamber comprises at least one passageway having a lower portion constituting said chamber.

6. A device for portioning out substantially constant volumetric doses from a mass of material composed of tangled fragments, said device comprising a chamber having an inlet and an outlet, said outlet having a wall, means for supplying said material to said chamber, said means being connected to said inlet, means for retaining said material at said inlet and a blade wheel for closing off said outlet, said blade wheel having a rotational axis and compartments, said compartments extending to part of the full length of said rotational axis, semicylindrical shields disposed symmetrically with respect to the center of said wheel for limiting the volume of said compartments and said shields having a height smaller than one-half the length of said rotational axis.

7. A device for portioning out substantially constant volumetric doses from a mass of material composed of tangled fragments, said device comprising a chamber having an inlet and an outlet, said outlet having a wall, means for supplying said material to said chamber, said means being connected to said inlet, means for retaining said material at said inlet, a rotatable studded cylinder for closing off said outlet, a passageway formed by said studded cylinder and said wall, detecting means for detecting said material in said passageway, and means for synchronizing the movements of said studded cylinder and of said means for retaining said material at said chamber inlet.

8. A device in accordance with claim 1, wherein said means for closing off said outlet of said chamber comprises a blade wheel.

9. A device in accordance with claim 8, wherein a space is provided between the wall of the opening which is closed off by the said wheel and the surface which is swept by the tips of the blades of said wheel.

Description:
When preparing gravimetric doses of long-shred tobacco or so-called standard cut-leaf tobacco in a device for making up doses of equal weight for machines designed to pack materials such as tobacco of the type described in U.S. Pat. No. 3,404,742, one of the problems presented is the need to minimize the degradation of shreds and particularly of long shreds.

In order to supply material either to a device of this type or alternatively, for example, to a device for reducing the cross-sectional area of a stream as described in U.S. Pat. application No. 622,794, filed on March 13, 1967, now Pat. No. 3,450,311 it is possible to make use of feeder and separator devices which are designed to deliver a stream of maximum uniformity from a mass of material. A fraction is withdrawn from the mass by the studded cylinder and conveyed by this latter into a passageway which corresponds in section to the desired stream; this stream or flow of material is removed from the studs by the stripping cylinder which rotates in the direction opposite to the studded cylinder. Degradation of the material under the action of these components remains of a low order on condition that the movements of the materials or of cut tobacco in the example under consideration upstream of the studded cylinder do not take place under pressure and that there does not exist any permanent volute at this level. In point of fact, if this condition is not satisfied, the longest shreds undergo degradation when the cut tobacco is taken by the studs of the cylinder.

The foregoing considerations hold particularly true when it is desired to supply a feeder and separator device under gravity by means of a duct even in the case of a duct of small height. The movements of the cut tobacco which result from the rotation of the cylinder will not take place freely and the pressure exerted will be more or less substantial.

Under these conditions, it appears desirable to limit the quantity which is present upstream of the studded cylinder to a volume such that compression phenomena which are liable to result in the formation of volutes are practically nonexistent. It is therefore necessary to constitute volumetric doses of material which are limited and as constant as possible.

However, it is difficult to constitute such doses from a heterogeneous mass formed of more or less tangled shreds which are liable to form lumps.

It is a specific object of the present invention to solve the problem which has just been discussed.

To this end, the invention is directed to a device for constituting substantially constant volumetric doses from a mass of material composed of tangled fragments. This device essentially comprises a chamber having an inlet and an outlet, means for supplying material to said chamber and connected to said inlet, means for retaining the material at said inlet and movable means for closing off said outlet.

The chamber can have a volume corresponding to that of the doses and accordingly serves as a dosing compartment.

Said chamber can also have a volume which is greater than that of said doses and in that case serves as an intermediate compartment or lock chamber.

The means for retaining material advantageously consist of at least one needle which is capable of moving transversely to the direction of flow of material, preferably by means of a retractable fork which serves to retain the material without causing any damage thereto.

The means for closing off the outlet of the chamber can consist of a blade wheel defining compartments which may or may not have the same dimensions and a space can be formed between the wall of the opening which is closed off by said wheel and the surface which is swept by the tips of the blades of said wheel; said wall can be slightly deformable in order to prevent any jamming or packing of the material and therefore any shearing which always results in irregularities in subsequent feeds by causing artificial formation of lumps in said material, particularly in the case of tobacco.

The means for supplying the chamber can consist of at least one duct or passageway which may be either vertical or inclined to the vertical and the lower portion of which constitutes the dosing chamber or lock chamber.

The means for closing off the outlet can consist of a blade wheel having compartments which do not extend to the full length of its rotational axis. The volume of said compartments can be limited in this case by semicylindrical shields disposed symmetrically with respect to the center of the wheel and having a height which is preferably smaller than one-half the length of the rotational axis.

It is thus possible to utilize a feed passage of fairly large size and thus to improve the downward flow of the mass of material. Moreover, the withdrawal of material which is effected alternately on each side of said mass is conducive to the disentangling of shreds. Finally, the fact that the ends of the shields do not extend to half the length of the rotational axis assists the transfer of shreds and prevents on the one hand any shearing action which would contribute to the degradation of the material and on the other hand any undesirable hanging effect or bridge formation.

The device in accordance with the invention is intended to feed a studded cylinder and, in this case, the said cylinder itself can constitute the movable means for closing off the outlet of the chamber.

In this case, the material is drawn out in the passageway formed between the said studded cylinder and the surrounding wall and means can be provided for detecting material which is present in the said passageway and for controlling in synchronism the movements of the said cylinder and of the means for retaining material at the chamber inlet.

Three embodiments of devices according to the invention for supplying standard out-leaf tobacco are shown in the accompanying drawings which are given without any implied limitation, and in which:

FIG. 1 is a view in isometric perspective showing a device for feeding by means of an endless conveyor and closing off by means of a studded wheel;

FIG. 2 is a sectional view of a device for closing off by means of a blade wheel;

FIG. 3 is a view looking on the rear end of the device of FIG. 2 but showing an alternative embodiment of the conveying system in which provision is made for a plurality of blade wheels disposed side-by-side, and

FIG. 4 is a view in isometric perspective showing a device for supplying material by means of a duct having substantial dimensions.

In the example of FIG. 1, provision is made for an endless-belt conveyor 1, a retractable fork 2 provided with teeth 3, a photoelectric cell 4, a casing 5 which surrounds the studded rotary cylinder 6, an opening 7 being formed in the top wall of the casing and surrounded by a small flange 8, a photoelectric cell 9, a sloping wall 10 of the casing, a vertical wall 11 of the casing which forms a continuation of said sloping wall.

The operation of the device is as follows:

At the outset, no shredded tobacco is present either on the teeth 3 of the fork or on the studded rotary cylinder which is stationary.

The endless-belt conveyor 1 which is shown in this case in the form of a feeding belt is then set in motion in the direction indicated by the arrow A. The cut-leaf of shredded tobacco is discharged onto the teeth 3 of the retractable fork 2 between the sides of the flange 8 which surrounds the opening 7. When a sufficient dose of shredded tobacco is formed on the teeth 3 of the fork as detected by the photoelectric cell 4, the feeding belt 1 comes to a standstill. Since there is no tobacco on the studded rotary cylinder 6, the fork withdraws. The dose of shredded tobacco which was retained by the teeth 3 of the fork 1 then falls onto the stationary studded cylinder 6 within the space formed between said cylinder and the teeth 3 of the fork 2. Once the tobacco has been discharged, the fork returns to is initial position and the conveyor is started up again.

As stated above, the dose of shredded tobacco rests on the studded cylinder within the space formed between the cylinder 6 and the fork 2, said space being larger than the volume of the dose, thereby permitting any random movement of the tobacco shreds as a result of rotation of the cylinder.

The rotary studded cylinder 6 is set in motion in the direction indicated by the arrow B. The tobacco which rests thereon is then carried in natural motion against the wall 10 of the casing 5 which is inclined so as to prevent any bridge effect.

The dose of shredded tobacco which rests on the wall 10 is progressively transferred by the studs of the cylinder 6 towards the passageway formed between said cylinder and the wall 11, and is consequently drawn out.

When there is practically no tobacco left on the studded cylinder as detected by the photoelectric cell 9, said cell causes the studded cylinder to stop and the fork to withdraw. It may be found advantageous to prevent any movement of rotation of the studded cylinder during the time of operation of the fork in order to prevent any hanging effect or bridge formation. It will be noted that, at the moment of stopping of the studded cylinder, a small quantity of tobacco to which will be joined the downstream end of the following dose will in practice remain within the passageway formed by said cylinder and the wall 11.

Once the dose of shredded tobacco has been delivered, a further operation then takes place.

In the example of FIGS. 2 and 3, the supply duct which is inclined to the vertical is designated by the reference numeral 11 whilst the reference numeral 12 designates a retractable needle. There is also shown a blade wheel 13 with its hubs 14, the wall 15 which is adjacent to the blade wheel, the system of brackets 16, 16' for driving the blade wheel, the discharge duct 17, three endless chains 18, 19 and 20 which are placed in juxtaposed relation, said chains being driven by means of the shaft 21 and adapted to carry the brackets 22, 23, 24 which are disposed in such a manner as to drive the corresponding blade wheels independently with respect to each other.

The operation of the device is as follows:

At the outset, no shredded tobacco is present on the blade-wheel 13 and the needle 12 is in the withdrawn position.

The shredded tobacco falls under gravity within the feed duct 11 and the top portion of the column is applied against the hub 14 of one of the quadrants of the blade-wheel 13.

The needle 12 then advances across the feed duct 11 and penetrates transversely into the stream of shredded tobacco.

The blade-wheel 13 then starts up and the rotational motion of this latter causes the dose of tobacco which is located downstream of the needle 12 to be carried downwards and delivered into the discharge duct 17. This dose is a function of the dimensional characteristics of the blade-wheel 13 and of the position of the needle 12. It should be noted that, in addition, the blade-wheel 13 can advantageously be rotated by an amount corresponding to two-fourths of a revolution in order to discharge the entire quantity of tobacco beneath the needle 12. In point of fact, it is found in the majority of cases that, after only one-quarter of a revolution, a small quantity of tobacco remains between the blade-wheel 13 and the needle 12. In order to take this into account, the volumes between blades can be different. This difference is obtained by adopting a different radius for the wheel hub in the case of different quadrants.

Although the blade-wheel 13 can be driven on the shaft in a conventional manner, the drive can also be carried out by means of a continuous-motion drive system comprising brackets 16 applied to the rear portion of the blade, thereby permitting the juxtaposed assembly of a plurality of wheels of the same type on a single shaft, said wheels being thus driven independently.

In the example of FIG. 2, when the endless chain which comprises two brackets moves in the direction of the arrow A, one of the two brackets 16 comes into contact with one blade, thereby driving the blade wheel in rotation in the direction of the arrow B. In this example, the blade wheel is caused to rotate by one-quarter of a revolution; the wheel 13 then stops until the bracket 16' comes into contact with the following blade. In order to produce a rotation corresponding to two-quarters of a revolution without any stopping of the wheel 13 between each revolution, it is only necessary to mount the requisite number of brackets on the endless chain in a suitable manner.

In the example of FIG. 3, the three endless chains 18, 19, 20 which each control the motion of three blade wheels by means of the brackets 22, 23, 24 are put into operation by means of the shaft 21 and rotate in synchronism. However, the corresponding blade wheels will not rotate in synchronism by reason of the fact that the brackets 22, 23, 24 are disposed in staggered relation, with the result that the blades of the wheels will not be driven at the same moment.

In the example of FIG. 4, there is shown the feed duct 31 which is inclined to the vertical, a tooth-bar 32 for retaining the tobacco, a blade-wheel 33 with semicylindrical shields 34 and 35, the conveyor-belt 36 which feeds the ducts 37 and 38 for the distribution of predoses and the duct 39 for the distribution of make-up doses as described in U.S. Pat. No. 3,404,742.

The operation of the device is as follows:

At the outset, there is no cut tobacco on the blade-wheel 33 and the tooth-bar 32 is withdrawn from the downward path of the tobacco.

The tobacco falls down within the duct 31 under the action of gravity. The left-hand portion of the column of tobacco is applied against the left-hand semicylindrical shield 34 whereas the right-hand portion of the column of tobacco falls into the compartments of the right-hand portion of the blade-wheel 33.

The tooth-bar 32 then advances through the supply duct 31 and penetrates transversely into the stream of tobacco.

The blade-wheel 33 then starts up in the direction of the arrow and performs a movement of rotation corresponding to one half-revolution. The shredded tobacco contained in the right-hand compartments falls onto the feeding belt 36. During the rotation of the blade-wheel 33, the column of tobacco is retained by the tooth-bar 32, thus permitting stripping of the shredded tobacco with a minimum of degradation.

When there is no longer a sufficient quantity of tobacco within one of the three ducts 37, 38, 39 as detected by any suitable means, the feeding belt 36 starts up and discharges the dose carried thereon into the duct which has called for said dose and then returns to its starting position.

When the blade-wheel 33 has carried out its half-revolution, the tooth-bar 32 again withdraws. It is then the left-hand portion of the column of tobacco which falls into the left-hand compartments of the blade-wheel 33. The tooth-bar 32 moves back into position, a dose is placed on the feeding belt and a further operation of supply to one of the ducts can then begin.