A cigarette-making machine has an air-pervious band which is arranged to carry the cigarette filler stream by means of suction applied through the band from a suction chamber, and includes ports through which air from the atmosphere is drawn by the suction from the suction chamber so that air flows inwards from both edges of the band over both surfaces thereof to help in clearing particles out of the gap between the band and the surface of a fixed member supporting the band.
Application Number:
05/173384
Publication Date:
05/14/1974
Assignee:
Molins Limited (London, EN)
Other Classes:
198/689.100, 131/84.400
International Classes:
A24C5/18; A24C5/00; A24C5/18
Field of Search:
131/23A,84,84B,84C,110 198/184
Primary Examiner:
Reich, Joseph S.
Attorney, Agent or Firm:
Craig & Antonelli
Claims:
I claim
1. In a cigarette making machine, the combination comprising means for forming a tobacco stream; a conveyor band for carrying the tobacco stream and having an air pervious mid-region in contact with the tobacco stream, and edge portions extending laterally from the tobacco stream; means providing a suction chamber in communication with the band; spaced walls for supporting respectively the edge portions of the band and for defining between them a suction space whereby the tobacco stream is held on the band by suction acting through the air-pervious mid-region of the band; spaced side rails for contacting and confining the sides of the tobacco stream, each edge portion of the band lying between one of the said side rails and one of the said spaced walls; and means defining at least one air flow passage adjacent to each edge of the band, the said passage communicating with the atmosphere, whereby air is drawn into the passage from atmosphere as a result of the suction pressure and flows, from the edge of the band and towards the mid-region of the band, at least between the corresponding edge portion of the band and the adjacent rail.
2. A cigarette making machine according to claim 1 in which the rails and walls are spaced apart by protrusion means which also serve to restrict sideways movement of the band.
3. A cigarette making machine according to claim 2 in which the protrusion means are formed on the walls.
4. A cigarette making machine according to claim 2 including a plurality of said flow passages adjacent to each edge of the band, each flow passage being at least partly defined by spaced opposed surfaces of the corresponding wall and rail and by two of said protrusion means.
5. In a cigarette-making machine, a cigarette filler stream conveying arrangement comprising means defining a suction chamber, an elongated air-previous band having lateral edges, means for driving said band longitudinally to carry a cigarette filler stream by means of the suction applied through the band from said suction chamber, and including fixed members supporting the edges of the band, and means defining ports which are elongated in the direction of the band and approximately aligned with said lateral edges thereof through which ports air from the atmosphere is drawn by the suction from said suction chamber so that air flows from both edges of the band towards the center of the band for clearing out particles between the band and the surface of at least one of said fixed members supporting each edge of the band.
6. In a cigarette-making machine, a cigarette filler stream conveying arrangement comprising means defining a suction chamber, an elongated air pervious band having lateral edges, means for driving said band longitudinally to carry a cigarette filler stream by means of the suction applied through the band from said suction chamber, rails supported along the lateral edges of said band for confining the sides of the cigarette filler stream, the edge portions of said band being supported on opposite faces respectively by said suction chamber and said rails, and means defining ports through which air from the atmosphere is drawn by the suction from said suction chamber, said ports communicating with the edges of the band so that air flows from both edges of the band and towards the longitudinal center of the band along both surfaces of the band for clearing out particles between the band and the surfaces of said rails and said suction chamber supporting the band.
7. In a cigarette-making machine, a cigarette filler stream conveying arrangement comprising means defining a suction chamber, an elongated air pervious band having lateral edges, means for driving said band longitudinally to carry a cigarette filler stream by means of the suction applied through the band from said suction chamber, rails supported along the lateral edges of said band for confining the sides of the cigarette filler stream, the edge portions of said band being supported on opposite faces respectively by said suction chamber and said rails, and means defining ports through which air from the atmosphere is drawn by the suction from said suction chamber so that air flows from both edges of the band and towards the center of the band for clearing out particles between the band and at least one surface adjacent thereto at each edge of the band, said suction chamber and said rails having spaced opposed surfaces defining between them at least some of the ports, said ports being approximately aligned with the edges of the band.
Description:
This invention is concerned particularly with cigarette making machines in which a cigarette filler stream is formed by showering tobacco on to the surface of an air-pervious band through which suction is applied to hold the stream on the band. Air flowing through the band as a result of the suction may also help to carry the tobacco towards the band. For example, the band may run along the top of a channel through which tobacco is carried upwards by air to form a filler stream against the underneath surface of the band, while suction is applied from a suction box above the band. Alternatively the tobacco may be showered downwards under gravity (possibly with the assistance of a downward air stream) on to the upper surface of a band below which there is a suction box.
In this specification the term "cigarette" will be used with the intention that it should be regarded as including other similar articles for smoking. The term "tobacco" will be used with the intention that it should be regarded as including any material or mixture of materials which may be used to form the filler of a cigarette or other similar article for smoking.
A cigarette making machine according to the present invention has an air-pervious band which is arranged to carry the cigarette filler stream by means of suction applied through the band from a suction chamber, and includes ports through which air from the atmosphere is drawn by the suction from the suction chamber so that air flows inwards from both edges of the band to help in clearing particles out of the gap between the band and the surface of a fixed member supporting the band.
The band may be of metal with solid edges. Alternatively, in the case of a woven band, for example of nylon, some fine tobacco particles may even lodge in the selve-edges of the band, in which case the inward flow of air may be such as to help also to dislodge the particles in the selve-edges.
An example of a cigarette making machine according to this invention is shown in the accompanying drawings. In these drawings:
FIG. 1 is a diagrammatic elevational view of part of the cigarette making machine;
FIG. 2 is an enlarged section on the line II--II in FIG. 1;
FIG. 3 is an elevational view from one side of FIG. 2;
FIG. 4 is an enlarged sectional view of part of FIG. 2; and
FIG. 5 is an enlarged section on the line V--V in FIG. 1.
The machine shown in FIG. 1 includes a channel 2 up which tobacco is carried by air so as to build up a cigarette filler stream on the undersurface of a band 4, the filler stream being held on the band by means of suction applied through the band from a suction chamber 6. Part of the air drawn up the channel 2 passes through a louvre port 8 connected to a supercharger fan (not shown).
The band 4 passes round two pulleys 10 and 12 and moves in the direction shown by the arrow. Thus the filler stream passes round the pulley 10 and then moves along the upper run of the band 4, past a trimmer 13, and is then received by a suction wheel 14 which carries the filler stream on to a continuous wrapper web. As shown by FIGS. 2 and 5, the height of the filler stream 18 downstream of the trimmer (FIG. 5) is less than the height upstream of the trimmer (FIG. 2).
The band 4 is for example of stainless steel and has solid edge portions with a perforated mid-region. In the region between the pulleys 10 and 12 the edge portions of the upper portion of the band run between rails 20 (which confine the sides of the filler stream 18) and inserts 22 fitted in walls 24 defining the suction chamber 6. At regular intervals along the band there are slots 26, leaving lands 28 which provide protrusions which guide the edges of the band so as to maintain the correct direction of movement of the band. Air is drawn in through the slots 26 and flows into the suction chamber 6, after passing along both the upper and lower surfaces of the edge portions of the band, as shown particularly by FIG. 4. It will be seen that the top outer edges of the inserts have chamfered portions 22A; this asists the movement of air between the band and the inserts, and furthermore ensures that the entire top surfaces of the inserts wear substantially evenly, without leaving ridges along the sides such as would be formed if the chamfering were omitted.
FIG. 5 shows how the air cleaning and band edges may be continued in the region of the pulleys 10 and 12. Air is drawn in through holes 30 (which may be of circular cross section) arranged at intervals along the band, so as to enter spaces 32 which extend substantial distances along the band and from which the air can flow into the suction chamber 6 in the same way as before. Instead of the holes 30 and spaces 32, there may be slots as shown in FIGS. 2 and 3. However, instead of the slots as shown in FIGS. 2 and 3, in the region between the pulleys 10 and 12, there may be holes and spaces as shown in FIG. 5.
The inserts 22 are of low-friction material, for example a plastics material.
The suction pressure in the suction chamber 6 may for example be about 500 mm water gauge. The suction may be created and maintained by any conventional means such as a fan, blower or the like.
It should be noted that the inflow of air between the band and the rails means that the gap between the band and the rails does not have to be kept as small as possible, as has hitherto been the case. The reason for previously keeping this gap small has been to avoid allowing tobacco shorts from the cigarette filler stream to escape through the gap. The air flow according to the present invention prevents the escape of shorts, and the gap need not be carefully controlled as hitherto, thus reducing the cost of machining.