British-american Tobacco Company Limited

Raymond J Harrison

John A Luke

Henry G Horsewell

John D Green

A tobacco-smoke filter has a filter body comprising at least one intermediate section which is located between end sections, has a cross section less than that of the end sections and lies wholly within the outline of the latter sections as viewed axially of the body, and a porous wrap of sheet material which is pervious to volatile constituents of tobacco smoke and which bounds, with the said body, at least one space affording a path through which smoke can pass when the filter is in use and from which said constituents are removed fom the smoke by diffusion through the said sheet material, each of the said sections being made of filter material. Suitably the body is of generally cylindrical form and composed of cellulose acetate. Advantageously the intermediate section is integral with at least one end section.

Tobacco-smoke filters

For shaping a component of a smoke filter, a rod of the material to be shaped and a heated former are relatively moved in contact with each other, in an arcuate path, in a direction transverse to the longitudinal axis of the rod, whereby an impression, for example an annular or helical groove, is produced in the rod by the former. For the said relative movement, the rod may be supported at the periphery of a rotor, while the former comprises a heated arcuate stator element or elements projecting inwardly towards the rotor. The rod may be turned about its axis during the relative movement, for example by a pair of rollers by which it is supported at the periphery of the rotor. A surface or surfaces bounding the impression, for example the bottom surface of a groove, may be sealed, during the shaping operation, so as to be smoke-impervious.

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Southampton, United Kingdom

Raymond J Harrison