US3769989A

US3769989A - Cigarette making machines

Info

Publication number: US3769989A
Application number: US00164505A
Authority: US
Inventors: F Labbe; E Preston; C Marritt
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1970-07-23
Filing date: 1971-07-21
Publication date: 1973-11-06
Anticipated expiration: 1990-11-06
Also published as: FR2099335A5; JPS5413519B1; GB1314826A; DE2136987B2; DE2136987A1

Abstract

Excess shreded tobacco is discarded from a filler stream moving on a conveyor in a cigarette making machine by trimming the excess and discarding the same therefrom. A pair of rotating disc knives having a rotating brush adjacent thereto removes the excess and the brush discards the same toward and against a plate that is rigidly mounted at one end thereof. The remainder of the plate flexes or bends in proportion with the mass flow rate or quantity of discard tobacco striking the same. The magnitude of the flexure is measured by strain gauges and is used as an indicator of the mass flow rate of the discard tobacco. A rigid plate having a pivotable mounting at one end and a spoon shape at the other may also be used, in which case, the indicator of the mass flow rate may include a screw conveyor adapted to pass discard tobacco against the spoon portion, a spring may be applied to limit displacement of the plate about the pivotable mounting and the plate is then used as one of two capacitive plates through which an electric circuit is passed, thereby providing a quantitiative indication thereof. Alternately, a restoring force may be applied to the plate by means of a fluid operated piston, the force necessary to prevent movement of the plate then provides the desired indicator.

Description

1451 Nov. 6, 1973 CIGARETTE MAKING MACHINES [75] Inventors: Francis Auguste Maurice Labbe,

Neuilly-sur-Seine, France; Edward George Preston; Clifford Russell Marritt, both of London, England [73] Assignee: Molins Limited, London, England [22] Filed: July 21, 1971 [21] Appl. No.: 164,505

[30] Foreign Application Priority Data July 23, l970 Great Britain 35,746/670 [52] us. Cl. 131/211), 131/84 C [51] lnt.Cl. ..A24c 05/34 [58] Field of Search 131/21, 21 D, 84,

' l3l/84C [56] References Cited UNITED STATES PATENTS 3,338,247 8/1967 1 Labbe .4 131 21 1) FOREIGN PATENTS OR APPLICATIONS 331,333 7 1930 Great Britain 131 84 c Primary Examiner-Joseph S. Reich Att0rney-Craig, Antonelli & Hill [57] g ABSTRACT Excess shreded tobacco is discarded from a filler stream moving on a conveyor in a cigarette making machine by trimming the excess and discarding the same therefrom. A pair of rotating disc knives'having a rotating brush adjacent thereto removes the excess and the brush discards the same toward and against a plate that is rigidly mounted at one end thereof. The remainder of the plate flexes or bends in proportion with the mass flowv rate or quantity of discard tobacco striking the same. The magnitude of the flexure is measured by strain gauges and is used as an indicator of the mass flow rate of the discard tobacco. A rigid plate having a pivotable mounting at one end and a spoon shape at the other may also be used, in which case, the indicator of the mass flow rate may include a screw conveyor adapted to pass discard tobacco against the spoon portion, a spring may be applied to limit displacement of the plate about the pivotable mounting and the plate is then used as one of two capacitive plates through which an electric circuit is passed, thereby providing a quantitiative indication thereof. Alternately, a restoring force may be applied tothe plate by means of. a fluid operated piston, the force necessary to prevent movement of the plate then provides the desired indicator.

12 Claims, 6 Drawing Figures CIGARETTE MAKING MACHINES This invention is concerned with cigarette making machines in which a trimmer removes part of the cigarette filler stream before the stream is enclosed in a wrapper to form a cigarette rod. The part of the stream removed by the trimmer may be termed the discard tobacco.

According to this invention a trimming unit for trimming the cigarette filler stream in a cigarette making machine includes means for throwing discard tobacco on to a plate, and means for monitoring the force which the tobacco applies to the plate, as an indication of the mass flow rate of the discard tobacco. A preferred arrangement is one in which the plate is resiliently movable and'in which the monitoring system is sensitive to the amount of movement of the plate.

In an alternative arrangement the plate is movable but is held in a substantially fixed position by a restoring force which varies automatically to balance the force of the tobacco on the plate, the monitoring system being sensitive tothe magnitude of the restoring force.

The movement of the plate may be converted into a signal to provide a visible indication of the mass flow rate of the discard tobacco. Alternatively, or in addition, a signal responsive to the movement of the plate may be used to control'the initial feed rate of the tobacco used to form the stream, so as to maintain the mass flow rate of the I discard tobacco substantially constant, for example as described in U.S. Pat. No. 3,338,247.

The plate is preferably arranged to deflect the stream of discard'tobacco towards a receiver, but as an alternative the inertia of the discard tobacco stream could be entirely lost in the impact with the plate.

In a preferred arrangement the trimmer comprises means, for example two cooperating discs, for separating the discard tobacco from the main body of the tobacco stream, and a rotary brush for brushing away the discard tobacco; the trimmer may for example be as described in U.S. Pat. No. 3,338,247. The brush in this case preferably throws the discard tobacco against the resiliently mounted plate.

An example of apparatus according to this invention is shown in the accompanying drawings. In these draw mgs:

FIG. 1 is a plan view of a double-disc trimmer with a rotary brush and a resiliently mounted deflector plate;

F IG. 2 is a side viewshowing the path of the deflected discard tobacco towards a feed screw;

FIG. 3 is a view of the deflector plate in a direction normal to theplane of the plate;

FIG. 4 is a block diagram illustrating the use of the inventionin a cigarette making machine;

FIG. 5 shows diagrammatically a different sensor plate; and

FIG. 6 shows diagrammatically another sensor plate in accordance with the present invention.

The trimmer shown in the drawings includes two discs 2 and 4 which rotate in opposite directions so that the adjacent parts of their peripheries move in the direction of the tobacco stream (that is to say, the cigarette filler stream) which approaches the trimmer in the direction of the arrows 6. The tobacco stream (not shown) is carried from above by an air-pervious band with the aid of suction. The band does not move quite horizontally but moves in a slightly downward direction parallel to the plane of the discs as shown in FIG. 2. The main body of the tobacco stream continues past the trimmer discs, but part of the stream is separated from the remainder by the discs, which can move up and down to vary the amount of discard tobacco.

Below the discs there is a rotary brush 8 consistingof a number of circumferentially spaced radial ribs 10 joined to an integral side wall. The brush is driven by a shaft 12 which moves up and down with the discs. As shown in FIG. 1, the shaft 12 is inclined to the line joining the centres of the discs, so that the brush throws the discard tobacco obliquely away from the remaining stream of tobacco along the direction of arrows 14. The stream of discard tobacco moving in the direction 14 hits'a deflector plate 16 which deflects the stream downwards in approximately the direction of the arrows 18. The discard tobacco-thus enters a trough 20 containing a feed screw 22 which carries away the discard tobacco; at the downstream end of the feed screw there may for example be another conveyor which feeds the discard tobacco back into the hopper of the cigarette making machine.

As shown best in FIG. 3, the deflector plate 16 is T- shaped and consists of a deflector portion 18, against which the discard tobacco impinges, and a narrower flexible portion 20. The deflector plate is mounted on a casing wall 23 by screws 24 passing through holes 26 in the end of the flexible portion 20. Thus the deflector plate is clamped to the casing but can move owing to the flexibility of the portion 20.

' The clamped end of the plate could alternatively lie outside the casing wall 23, and the portion 20 of the plate could pass through a slot in the casing wall.

Between the clamped end and the deflector portion 18, strain gauges 28 are bonded to both sides of the flexible portion 20 of the plate. Electrical leads 30 from the strain gauges are connected to any suitable electrical circuit by which the amount of movement of the plate can be detected as a result of the changing resistance of the strain gauges due to varying degrees of flexing of the portion 20-of the plate.

In one preferred arrangement shown diagrammatically in FIG. 4 the signal provided an electrical circuit 32 in response to the movement of the deflector plate is fed via an amplifier 34 into an integrator circuit 36 from which an average signal (i.e. representing the average over a predetermined interval of time) is transmitted to a device 38 for varying the speed of the cigarette machine hopper 40 in order to maintain the mass flow rate of the discard tobacco at a substantially constant level. For example, the proportion of tobacco removed from the tobacco stream by the trimmer may be set approximately at a value of between 20 percent and 25 percent by weight of the initial tobacco stream formed from the tobacco delivered by the hopper.

Instead of being flat as shown in the drawings, the deflector portion of the plate may be concave, for example spoon-shaped, as shown by the deflector portion 18' in FIG. 5, to help in concentrating the stream of discard tobacco deflected by the plate; that is to say, to prevent the stream from spreading excessively upon impact with the plate.

Instead of -the deflector portion of the plate being movable by virtue of flexing of part of the plate, the plate may be more rigid, as shown in FIG. 5, and may be pivotally mounted at 42 on the casing, with a spring 44 to restrain pivotal movement. In this case pivotal movement of the plate against the action of the spring may for example be monitored by any sort of displacement transducer; for example, the plate may cooperate with a fixed plate 46 to form a capacitor so that the capacitance between the two plates varies according to the position of the deflector plate.

Instead of the resiliently movable deflector plate being mounted in the path of the discard tobacco stream thrown from the trimmer by the rotarybrush, the deflector plate may for example be mounted at the discharge end of the feed screw 22, as shown in FIG. 5. In this case the feed screw would throw the tobacco against the plate, and the movement of the plate would again give an indication of the mass flow rate of the discard tobacco.

FIG. 6 shows part of a pivotally mounted deflector plate 18 similar to the deflector plate 18' in FIG. 5. However, instead of the displacement transducer of FIG. 5, there is a fluid-powered device 48 which is connected to the plate 18" and applies a restoring force which varies automatically so as to balance the force applied to the plate by the tobacco and thus hold the plate in a substantially fixed position. The magnitude of the restoring force is an indication of the mass flow rate of the tobacco.

We claim:

1. A trimming unit for trimming discard tobacco from a cigarette filler stream in a cigarette making machine, including a plate, means for throwing said discard tobacco on to said plate, and means for monitoring the force which the discard tobacco applies to the plate as an indication of the mass flow of the discard tobacco.

2. A trimming unit according to claim 1 including means for mounting said plate in position to receive said tobacco and in which at least the part of the plate engaged by the tobacco is resiliently movable, said another part of the plate which is rigidly mounted at one end.

4.. A trimming unit according to claim 3 including strain gages secured to the flexible part of the plate for monitoring the movement thereof.

5. A trimming unit according to claim 1 including movable mounting means at one end of the plate automatic means for applying a restoring force adapted to monitoring means being sensitive to the amount of movement of the plate.

3. A trimming unit according to claim 2 including means for rigidly mounting said plate at one end thereof and in which the part of the plate which is struck by the tobacco can move as a result of flexing of balance the force of the tobacco on the plate, the monitoring means being sensitive to the magnitude of the restoring force.

6. A trimming unit according to claim 5 in which the automatic means includes a fluid-powered device.

7. A trimming unit according to claim 1 in which the plate is arranged to deflect the discard tobacco towards a receiver.

8. A trimming unit according to claim 7 in which the part of the plate which is struck by the tobacco is concave so as to reduce the tendency of the discard tobacco stream to spread after impact with the plate.

9. A trimming unit according to claim 1 including a rotary brush arranged to throw the discard tobacco towards the plate.

10. A trimming unit according to claim 9 including two cooperating rotating discs which separate the discard tobacco from the filler stream and wherein the brush removes the separated tobacco therefrom.

11. A cigarette making machine according to claim 1 including adjustable means for forming said filler stream, means to convey said stream through said trimming unit and means responsive to said monitoring means for controlling said adjustable means so as to maintain the mass flow rate of discard tobacco substantially constant.

12. A trimming unit for trimming the cigarette filler stream in a cigarette making machine, including means for throwing discard tobacco on to a deflector plate, said plate comprising a wide part which is struck by the discard tobacco, and a narrow, flexible part which is mounted at one end on a fixed structure, and including strain gauges which are secured to the narrow part of the plate and provide an output signal indicative of the amount by. which the narrow part of the plate is flexed by the force of the tobacco.

Claims

2. A trimming unit according to claim 1 including means for mounting said plate in position to receive said tobacco and in which at least the part of the plate engaged by the tobacco is resiliently movable, said monitoring means being sensitive to the amount of movement of the plate.

3. A trimming unit according to claim 2 including means for rigidly mounting said plate at one end thereof and in which the part of the plate which is struck by the tobacco can move as a result of flexing of another part of the plate which is rigidly mounted at one end.

4. A trimming unit according to claim 3 including strain gages secured to the flexible part of the plate for monitoring the movement thereof.

5. A trimming unit according to claim 1 including movable mounting means at one end of the plate automatic means for applying a restoring force adapted to balance the force of the tobacco on the plate, the monitoring means being sensitive to the magnitude of the restoring force.

12. A trimming unit for trimming the cigarette filler stream in a cigarette making machine, including means for throwing discard tobacco on to a deflector plate, said plate comprising a wide part which is struck by the discard tobacco, and a narrow, flexible part which is mounted at one end on a fixed structure, and including strain gauges which are secured to the narrow part of the plate and provide an output signal indicative of the amount by which the narrow part of the plate is flexed by the force of the tobacco.