GB2159691A

GB2159691A - Machines for making cigarettes and similar rod-like articles

Info

Publication number: GB2159691A
Application number: GB08513894A
Authority: GB
Inventors: Michael Jozef Soborowski
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1984-06-04
Filing date: 1985-06-03
Publication date: 1985-12-11
Also published as: FR2565073A1; IT8548159A0; DE3519767A1; GB2159691B; GB8414215D0; FR2565073B1; GB8513894D0; JPS6138894A; IT1182731B; IT8548159A1

Abstract

A ledger for a cigarette or filter cut-off comprises rod-supporting member 10 mounted on a tape 20 which is secured to an oscillating drive member 34 and also passes around a guide pulley 28 such that a part of the tape which extends between the drive member of the pulley and carries the rod-supporting member extends in a straight line and reciprocates linearly as a result of oscillation of the drive member. <IMAGE>

Description

SPECIFICATION Machines for making cigarettes and similar rod-like articles This invention is concerned with ledgers for use in cutting acontinuouscigarette orsimilar rod at regular intervals. The ledger supports the continuous rod while it is being cut by a rotary knife. While each cut is being made, it is usual for both the knife and the ledger to move with the rod so that the latter is not held up while it is being cut.

A ledger according to this invention comprises a rod-supporting member mounted on a tape which is securedtoan oscillatory drive memberand also passes around a guide pulley such that a partofthe tape which carries the rod-supporting member extends in a straight iine between the drive member and the pulley and reciprocates linearly as a result of oscillation ofthe drive member.

In a preferred construction, the drive member comprises a pulley and is oscillated by a crank mechanism.The anglethrough which it oscillates can be altered, in conjunction with alteration ofthe knife speed, to vary the length of the cut rods. Alteration of the angle of oscillation is preferably achieved by adjustment of the crank radius.

The guide pulley is preferably an idler, being driven by the tape itself. It is preferably urged away from the driven pulley,forexample byaspring or pneumatic jack, so as to tension the tape.

One advantage of this invention is that it enables the rod to be closely guided by the rod-supporting member while it is being cut. The rod-supporting member preferably comprises two co-axial tubes arranged end to end with a slight gap between them through which the knife passes to cut the rod. Since the rod supporting member moves linearly (in the direction of movement of the rod) it can be formed with minimal clearance around the rod so asto guide the rod very precisely and to prevent deflection or bulging of the rod during cutting.

An example of a ledger according to this invention is shown in the accompanying drawings. In these drawings: Figure lisa front elevation of the ledger; and Figure 2 is a plan view of the ledger.

As shown in the drawings, the ledger comprises a rod-supporting member 10 consisting of two tubes 12 and 14 carried by brackets 16 and 18 secured to a tape 20, which may be of metal, for example spring steel. A continuous rod 22 enters the ledgertubes and is cut at regular intervals by a knife 24 (see Figure 2) carried by a rotating body 26. The knife arrangement may, for example, be as described in our British Patent Specification No.1238460.

As shown in Figure 1, the upper run of the tape 20 which carries the rod-supporting member extends along a straight line which is parallel to the axis of the rod 22. The tape passes around an idler pulley 28 and has its ends secured by screws 30 and 32 to a drive pulley 34. Alternatively, the tape may be endless, but it should in any event befirmlysecured to the drive pulley 34to ensure propertiming of the rodsupporting member with respect to the knife as the latter passes through the rod.

Oscillatory motion of the drive pulley 34 is achieved by means of a crank arrangement 36 comprising a rotary part 38 carrying a crank pin 40 by which a connecting rod 42 is pivotally connected to the rotary part 38. Afurther pin 44, mounted between outwardly projecting parts 43 and 45 integral with the pulley 34, pivotally connects the upper end of the connecting rod to a rearward extension ofthe pulley 34, as shown in Figure 2. The rotary part 38 is formed with a gear 39 which meshes with a drive gear41.

The angle of oscillation ofthe drive pulley 34, and hence the stroke of the rod-supporting member, can be altered by adjusting the radial distance of the pin 40 from the axis of the rotary part 38. This may be achieved in anywell known manner,forexample by means of a radially disposed screw engaging a nut carrying or attached to the pin 40. Asmaller radius (shorter stroke) position of the pin 40 is shown in broken outline at the position 40A.

As shown by the arrow in Figure lithe rotary member 38 is driven in a counter-clockwise direction.

Therefore it will be seen that the connecting rod 42 at the illustrated moment of time is moving downwards and is therefore moving the rod-supporting member 10 to the left; that isto say in the direction of movement of the rod 22. The rod-supporting member 10 is approximately mid-way along its stroke, and at thatstagethe knife (notshown in Figure 1) is approximately halfway through the rod. After a further 90 degrees of rotation of the member 38, the connecting rod 42 begins to rise and reverses the direction of motion of the rod-supporting member; at that stage the knife is clear of the ledger, allowing the ledger to return to its position ready for supporting the rod during the next cutting pass of the knife.

In the configuration shown in the drawings, the knife head 26 lies behind the ledger and moves downwards while cutting the rod; this allows the cutting movement of the knife to be in a direction normal to the plane of the tape. For that purpose, the brackets 16and 18 supporting the tubes 12 and 14 project sideways (rearwards) from the edge of the tape, as show in Figure 2; and as a balance, there are corresponding weights 44 and 46 which project forwards from the tape. During each cutting stroke of the knife there will be a tendency for the resulting downward force on the rod (caused by the resistance of the rod to the passage ofthe knife through it) to twist and deflect the tape.If necessary, to prevent that (orto restrict it) there may be a fixed straight guide 48 below parts ofthe brackets and parallel to the direction of movement of the brackets, along which the brackets slide during cutting; there may be a small clearance between the brackets and the guide so as to avoid rubbing contact except during cutting.

As an alternative, the entire ledger could be tilted through 90 degrees or the knife head could be above the tape so that the motion of the knife during cutting is approximately parallel to the surface of the tape. In either of these cases the rod-supporting tubes could be centrally placed with respective to the tape and there would be no need for balance weights.

As a further alternative, the single broad tape shown in the drawings could be replaced by two narrower laterally-spaced tapes, both secured to the bracket or brackets carrying the rod-supporting tubes.

Claims

1. A ledgerfor use in cutting a continuous cigarette or similar rod at regular intervals, comprising a rod-supporting member mounted on a tape which is secured to an oscillatory drive member and also passes around a guide pulley such that a part of the tape which carries the rod-supporting member extends in a straight line between the drive member and the pulley and reciprocates linearly as a result of oscillation of the drive member.

2. A ledger according to claim 1 in which the drive membercomprises a pulleyto which the tape is secured.

3. A ledger according to claim 1 or claim 2 in which the drive member is arranged to be oscillated by a crank mechanism.

4. A ledger according to claim 3 in which the crank radius is adjustable to alter the angle of oscillation of the drive member.

5. A ledger according to any one of claims 1 to 4 in which the guide pulley is an idler, being driven in an oscillatory member by the tape.

6. A ledger according to claim 5 in which the guide pulley is driven by frictional contact with the tape.

7. A ledger according claim 6 including means for urging the guide pulley away from the drive member to tension the tape.

8. A ledger according to any one of claims 1 to 7 in which the tape is of metal.

9. A ledger according to any one of claims 1 to 8 in which the rod-supporting member projects sideways from the tape, allowing cutting movement of a knife in a general direction which is normal to the plane ofthe tape.

10. A ledger according to claim 9 including at least one balance weight projecting sideways from the tape in the opposite direction to the rod-supporting member.

11. Aledgeraccording any one of claims 1 to 10 including a fixed straight guide member arranged during cutting to prevent or restrict twisting or deflection ofthe tape by contactwith the rodsupporting member.

12. Aiedgeraccordingto Claim 1 andsubstantially as described with reference to the accompanying drawings.