GB1587816A

GB1587816A - Cigarette making machines

Info

Publication number: GB1587816A
Application number: GB477780A
Authority: GB
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1977-06-01
Filing date: 1977-06-01
Publication date: 1981-04-08

Description

(54) IMPROVEMENTS RELATING TO CIGARETTE MAKING MACHINES (71) We, MOLINS LIMITED, a British Company, of 2 Evelyn Street, Deptford, London SE8 5DH, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention is concerned with the hoppers of cigarette making machines. The hopper of a cigarette making machine is used to form a metered flow of tobacco which may be received intermittently by the machine. The metered flow is converted, in another part of the machine, into a cigarette filler stream which is enclosed in a wrapper to form a cigarette rod.

In this context the term "tobacco" is intended to include tobacco substitutes; and the term "cigarette" is intended to include other similar rod-like articles for smoking, for example small cigars which are made in a similar manner to cigarettes.

According to the present invention, a hopper for a cigarette making machine comprises an elevator for feeding a stream of tobacco from a mass of tobacco adjacent to the elevator, means for feeding into the hopper discard tobacco removed from the cigarette filler stream and for feeding the discard tobacco onto the elevator before the elevator receives tobacco from the mass of tobacco, and means for receiving from the elevator the combined discard and other tobacco and for delivering that combined tobacco to a cigarette filler forming device.

Examples of hoppers according to this invention are shown in the accompanying drawings. In these drawings: Figures 1 and 2 are diagrammatic sectional views of different hoppers according to this invention; Figure 3 is an enlarged view showing a possible design of part of the hopper; and Figure 4 is a partly sectional view in the direction of the arrow IV in Figure 3.

The hopper shown in Figure 1 has parallel walls 10 and 11 defining a tobacco inlet channel extending obliquely downwards. The length of the channel is sufficient to accommodate a buffer store of tobacco, for example about 3 cubic feet. Tobacco may be fed into the upper end of the channel 10, 11 in any convenient way.

The angle of inclination to the vertical of the channel 10, 11 is such that the tobacco is just able to slide down when allowed to do so by a spiked roller 13; the angle could be even greater if the wall 11- is coated with a low friction material such as ultra-high molecular weight polyethylene.

When the roller 13 rotates (in a counterclockwise direction) it allows tobacco to drop from the lower end of the channel 10, 11; when the roller 13 stops rotating, it holds up the tobacco. As an additional safeguard (especially for "long" tobacco which tends to tangle up) there is a doffer roller 12 which may rotate continuously, for example at a speed of about 120 r.p.m. This manner of feeding tobacco minimizes degradation of the tobacco and is useful in its own right.

The width of the tobacco shower delivered by the channel 10, 11 (measured in the direction of the axes of rollers 12 and 13) may be changed (e.g. increased) as follows: Inclined side walls 14 and 15 are each formed with a number of downwardly extending vanes 14A and 15A; these vanes may, for example, diverge slightly in a downward direction if the tobacco shower is required to be increased. This may be necessary if the width of the tobacco discharge unit feeding the channel 10, 11 is less than the width of the eventual carpet of tobacco which the hopper is required to produce (on band 78).

The tobacco arrives in a space 79 adja,- cent to a spiked elevator band 67.

The hopper also includes a downwardly extending channel 65, 66 into which tobacco is fed with the aid of the elevator band 67.

Tobacco received from the elevator band 67 is projected by a projector roller 68 towards a ramp 69 and slides down the ramp and into the channel 65, 66 while heavy foreign bodies pass over the top edge 69A of the ramp and are rejected.

Tobacco is fed continuously from the lower end of the channel 65, 66 by a sixroller - arrangemelnt by which the tobacco stream leaving the channel 65, 66 is divided into two streams one of which passes between a roller 70 and a fixed wall 71 while the other passes between a roller 72 and a fixed wall 73. The two streams are received respectively by rollers 74 and 75 which have cooperating picker rollers -76 and 77 which project the tobacco downwards onto a band 78, producing a spread shower along the band as indicated by the arrows.

Tobacco is received by the elevator band 67 from the tobacco - space 79, which is defined partly by an oscillating plate 80. The plate 80 reciprocates, with slow strokes towards the elevator and fast return strokes, about a horizontal pivot axis 81 at its upper end so as to feed tobacco onto the elevator band 67. A fixed plate 82 is positioned adjacent to the lower end of the plate 80 so as to stop large quantities of tobacco falling down from the space 79 while the lower end of the plate 80 is spaced from the band 67.

Discard tobacco is fed by a vibrating tray 83 into a well 84 near the lower end of the upward-moving run of the band 67, so that discard tobacco is fed onto the elevator before the elevator receives tobacco from the mass of tobacco 19 in the space 79. The well 84 is defined on one side by a wall 85 onto which the tray 83 delivers the discard tobacco. It-should be noted that the wall 85 extends obliquely downwards towards the band 67 and that the band 67 is inclined to the vertical in a direction away from the wall 85.

Instead of being pivoted about a fixed axis at 81, the oscillating plate 80 may be suspended at its upper end by a number of springs so that the upper end can move at least to a limited extent in a horizontal direction. As a result, movement of the plate 80 towards and away from the elevator band 67 is less positive, having slight flexibility as a result of the spring suspension. The mean position and/or stroke of the plate 80 or 85 may in either case be adjustable.

The oscillating plate 80 may have a lowfriction coating on its face contacting the tobacco. For example, the coating may be of ultra-high molecular weight polyethylene.

The hopper also includes a roll detector 20 as described in Patent Application No.

36468/78 (Serial No. 1,587,815) which was also divided from the Application No.

22902/76 (Serial No. 1,587,814) from which the present application was divided. Atten tion is directed to both those applications.

In order to accommodate different tobacco, the assembly comprising the elevator band 67, its associated pulleys, and possibly the refuser roller 22, may be adjust able about the axis of the upper pulley 67A to adjust the angle of inclination to the vertical of the band 67, e.g. between limits of 15 and 25". The mean position of the oscillating plate: 80 would in that case be adjusted as appropriate.

Figure 2 shows part of a different hopper.

Walls 90, 91 (which may have vanes like the vanes 14A and 15A identified in Figure 1) guide tobacco which is fed downwards (e.g. from feed rollers 12 and 13 as in Figure 1) onto a projector roller 92 formed with a number of circumferentially spaced axial ribs 92A. The tobacco arrives at somewhat random positions across the width of the roller 92 and is accordingly projected along varying trajectories onto the band 93 feeding the tobacco towards an elevator band 94; as a result of the varying trajectories of the tobacco, the tobacco tends to be spread somewhat along the length of the band 93 thus helping to maintain a layer of tobacco of substantially uniform thickness on the band 93 in the region of the elevator band 94. The thickness of the layer of tobacco presented by the band 93 to the elevator may, for example, be in the region of 100 mm to 225 mm.Discard tobacco is returned by a vibrating tray conveyor 95 to the lower end of the elevator band 94. As in the hopper shown in Figure 1, the band 96 delivering the final carpet of tobacco passes below the elevator 94 so that any particles of tobacco which drop between the elevator 94 and a fixed wall 97 fall onto the band 96.

Figure 3 shows an arrangement which can be used in the region of the upper end of the elevator band in Figure 1. It shows the construction of the elevator band (identified here as band 18) and of the associated unraveller roller 23.

The elevator band 18 has transversely extending rows of spikes 100A (see Figure 4) formed by metal slats 100 which have recesses 100B at regular intervals along the outer edges of the slats so as to leave spike portions 100A between the recesses. Each slat is carried by a metal strip 102 which is secured to the band 18, e.g. by bolts 104.

The unraveller roller 23 has a number of axially spaced groups of spikes 23A, each group comprising six spikes. The spikes enter the recesses 100B of the slats on the band, as shown in Figure 4. It will be understood that the recesses in successive slats are aligned for that purpose.

The inner rib-like portions 6f the slats adjacent to the band 18 serve as pockets which can convey upwards small particles of tobacco which spikes alone cannot convey. By way of example, a cluster 106 of such particles of tobacco is shown in Figure 4. It will be understood that the small particles of tobacco fall from the band 18 at the same time as larger strands of tobacco are stripped from the band with the aid of the unraveller roller 23.

By way of example, the slats 100 on the band 18 may be at about 20 mm intervals.

However, in order to reduce the tendency for tobacco to roll in the tobacco space adjacent to the elevator band, occasional slats may be omitted. For example, every fourth slat may be omitted.

The feed roller 13 (Figure 1) may have spikes formed by recessed slats similar to the slats 100 shown in Figure 3. On the other hand, the doffer roller 12 may have non-recessed slats curved backwards relative to the direction of rotation, as shown in Figure 1.

WHAT WE CLAIM IS:- 1. A hopper for a cigarette making machine comprising an elevator for feeding a stream of tobacco from a mass of tobacco adjacent to the elevator, means for feeding into the hopper discard tobacco removed from the cigarette filler stream and for feeding the discard tobacco onto the elevator before the elevator receives tobacco from the mass of tobacco, and means for receiving from the elevator the combined discard and other tobacco and for delivering that combined tobacco to a cigarette filler forming device.

2. A hopper according to claim 1 in which the elevator comprises a spiked band.

3. A hopper according to claim 2 in which the discard tobacco is arranged to be fed onto the upwardly moving run of the elevator band at a position below the mass of tobacco.

4. A hopper according to claim 3 in which the discard tobacco is arranged to be delivered into a space formed between the upwardly moving run of the elevator band and a wall extending obliquely downwards towards the band.

5. A hopper according to claim 4 in which the upwardly moving run of the elevator band is inclined to the vertical in a direction away from the downwardly extending wall.

6. A hopper according to claim 4 or claim 5 in which the means for returning discard tobacco into the hopper includes a conveyor which delivers the discard tobacco onto the downwardly inclined wall.

7. A hopper according to any one of claims 4 to 6 in which the means for returning discard tobacco includes a vibratory tray extending across the downwardly inclined wall.

8. A hopper according to any one of claims 4 to 7 including a conveyor band which receives the combined discard and other tobacco from the elevator and feeds it towards the filler forming device, this band being arranged to pass below the elevator and to receive any discard tobacco which escapes between the downwardly inclined wall and the elevator.

9. A hopper according to any one of claims 1 to 8 in which the means for feeding the mass of tobacco towards the elevator comprises an approximately horizontal conveyor.

10. A hopper according to claim 1 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. which can convey upwards small particles of tobacco which spikes alone cannot convey. By way of example, a cluster 106 of such particles of tobacco is shown in Figure 4. It will be understood that the small particles of tobacco fall from the band 18 at the same time as larger strands of tobacco are stripped from the band with the aid of the unraveller roller 23. By way of example, the slats 100 on the band 18 may be at about 20 mm intervals. However, in order to reduce the tendency for tobacco to roll in the tobacco space adjacent to the elevator band, occasional slats may be omitted. For example, every fourth slat may be omitted. The feed roller 13 (Figure 1) may have spikes formed by recessed slats similar to the slats 100 shown in Figure 3. On the other hand, the doffer roller 12 may have non-recessed slats curved backwards relative to the direction of rotation, as shown in Figure 1. WHAT WE CLAIM IS:-

1. A hopper for a cigarette making machine comprising an elevator for feeding a stream of tobacco from a mass of tobacco adjacent to the elevator, means for feeding into the hopper discard tobacco removed from the cigarette filler stream and for feeding the discard tobacco onto the elevator before the elevator receives tobacco from the mass of tobacco, and means for receiving from the elevator the combined discard and other tobacco and for delivering that combined tobacco to a cigarette filler forming device.

2. A hopper according to claim 1 in which the elevator comprises a spiked band.