GB1581723A - Cut-off mechanisms of cigarette and other continuous rod making machines - Google Patents

Description

(54) IMPROVEMENTS RELATING TO CUT-OFF MECHANISMS OF CIGARETTE AND OTHER CONTINUOUS ROD 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 ledgers associated with cut-off devices used in continuous rod making machines, particularly cigarette and cigarette filter making machines. The ledger is a device which supports the rod during cutting.

According to one aspect of the present invention, a part of the ledger which engages the rod to support it during cutting has, near the cutting position, an aperture through which suction is applied to urge the rod towards the rod-engaging part of the ledger.

As a result of the suction, the rod is more precisely located and supported by the ledger. This may in suitable arrangements improve the quality of the cut and in any event defines more precisely the path of the rod, assuming that the suction aperture is in the part of the ledger upstream of the cutting position. The latter advantage, in the case of a cigarette making machine with a Beta ray or other rod weight monitoring device located immediately upstream of the ledger, facilitates the weight monitoring since the path of the rod is more precisely defined.

This invention is particularly applicable to a fixed ledger. Such ledgers have been proposed in the past but have not been regarded as entirely satisfactory since they do not include a part which reciprocates in unison with the rod during cutting. In a preferred fixed ledger according to the present invention, the rod is supported upstream and/or downstream of the cutting position by a tubular member (through which the rod passes) formed with at least one suction aperture to urge the rod against the side of the tube towards which the rod tends to be urged by a knife during cutting. The application of suction may also tend to "puff out" the wrapper during cutting.

An example of a fixed ledger according to this invention is shown in the accompanying drawings. In these drawings: Figure 1 is a longitudinally sectioned side elevation of the ledger; and Figure 2 is a section on a larger scale on the line II-II in Figure 1.

The ledger shown in the drawings is used to support a continuous rod 10 while it is being cut at regular intervals by a knife 11.

which may be as described in our British patent specification No. 1,238,458.

The ledger itself includes a fixed tubular part 12 which supports the rod 10 upstream of the cutting position, and a fixed tubular part 13 lying downstream of the cutting position. The downstream end of the part 12 has an oblique edge 12A along which the knife moves during cutting. The knife is shown in solid outline in a position in which it is about to enter the rod, and is shown in chain dotted outline in a subsequent position in which it has moved partly through the rod and has moved axially at the same speed as the rod.

Near the cutting position the tubular part 12 is formed with an aperture 14 and preferably also with apertures 14' through which suction is applied from a suction chamber 15.

This suction tends to urge the rod 12 downwards, it being assumed that the knife 11 moves downwards during cutting. The orientation of the entire arrangement about the axis of the rod could, however, be different.

Further apertures 16, 17, 18 and 19, all in a common plane with the aperture 14, are formed in the tubular part 12 to allow an inflow of air from the atmosphere. Without these apertures 16 to 19, air would have to flow axially along the rod towards the aperture 14. However, it should be noted that the apertures 16 to 19 are of smaller cross sectional area than the aperture 14 so that there is an air pressure of below atmospheric pressure between the rod 10 and the surrounding tubular part 12.

WHAT WE CLAIM IS: 1. A ledger for use in a cigarette or other continuous rod making machine for supporting the rod during cutting, in which a part of the ledger which engages the rod to support it during cutting has, near the cutting position, an aperture through which suction is applied to urge the rod towards the rod-engaging part of the ledger.

2. A cigarette making machine including a ledger according to claim 1 and a rod weight monitoring device located immediately upstream of the ledger.

3. A ledger for use in a cigarette or other continuous rod making machine for supporting the rod during cutting, in which the rod is supported upstream and/or downstream of the cutting position by a tubular member (through which the rod passes) formed with at least one suction aperture to urge the rod against the side of the tube towards which the rod tends to be urged by a knife during cutting.

4. A ledger according to claim 3, including at least one air inlet hole formed in the tubular member at a position circumferentially spaced from the suction aperture.

5. A ledger according to claim 4 in which the air inlet hole has a smaller cross-section than the suction aperture, the arrangement being such that the air pressure between the rod and the surrounding tubular member during use is below atmospheric.

6. A ledger substantially as described with reference to the accompanying drawings.

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

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. is an air pressure of below atmospheric pressure between the rod 10 and the surrounding tubular part 12. WHAT WE CLAIM IS:

1. A ledger for use in a cigarette or other continuous rod making machine for supporting the rod during cutting, in which a part of the ledger which engages the rod to support it during cutting has, near the cutting position, an aperture through which suction is applied to urge the rod towards the rod-engaging part of the ledger.

2. A cigarette making machine including a ledger according to claim 1 and a rod weight monitoring device located immediately upstream of the ledger.

3. A ledger for use in a cigarette or other continuous rod making machine for supporting the rod during cutting, in which the rod is supported upstream and/or downstream of the cutting position by a tubular member (through which the rod passes) formed with at least one suction aperture to urge the rod against the side of the tube towards which the rod tends to be urged by a knife during cutting.

4. A ledger according to claim 3, including at least one air inlet hole formed in the tubular member at a position circumferentially spaced from the suction aperture.

5. A ledger according to claim 4 in which the air inlet hole has a smaller cross-section than the suction aperture, the arrangement being such that the air pressure between the rod and the surrounding tubular member during use is below atmospheric.

6. A ledger substantially as described with reference to the accompanying drawings.