Abstract: Tobacco smoke filters and methods and means for making same wherein the products have an elongated hollow inner member overwrapped with a conventional plug wrap, with an intermediate member interposed therebetween. The intermediate member is comprised preferably of a filtering material different from that which forms the inner member so as to provide selective filtration through the two layers of filtering material, the intermediate member functioning to remove larger particles of undersirable material so that the interstitial spaces of the inner member are not clogged thereby. Moreover, the presence of the intermediate member provides a smooth outer surface for attaching a conventional plug wrap without the need for an internal glue line. The inner member is formed continuously as a crimped rod and is used in place of the mandrel for forming the hollow intermediate member thereover.

Abstract: Tobacco smoke filters and methods and means for making same wherein the products have an elongated annular intermediate member overwrapped with a conventional plug wrap, with discrete inner plugs of a length shorter than the intermediate member and offering at least as much resistance to passage of smoke as the intermediate member, being secured within the intermediate member against axial displacement. The inner member may be formed of a filtration material, as is the intermediate member, or the inner member may be formed of a material which is non-permeable to smoke. Portions of the intermediate member may be crimped to embed them into the inner member thereby improving the engagement between these members. The inner member may be centrally positioned within the intermediate member to form cavities at each end of the filter or, alternatively, the inner member may be secured at one end of the intermediate member to provide only a single inner cavity.

Abstract: The invention provides a process for the continuous production of an elongate smoke filtering member comprising a heat-activatable bonding material and having air-permeable deformations at longitudinally displaced positions along its length, which comprises continuously advancing longitudinally a rod-like body of the material of the member, intermittently passing a hot fluid laterally into the advancing body to activate the bonding material substantially only at separate longitudinally displaced regions of the body, and deforming the outer surface of the advancing body at such regions where the bonding material is activated. Apparatus for performing the method comprises means for continuously longitudinally advancing the rod-like body, means for passing a hot fluid laterally into the body at regions longitudinally displaced along the body, and means for deforming the outer surface of the body at said regions.

Abstract: Tobacco smoke filters wherein the products have both internal and external cavities, with the external cavities being of a limited nature so as to provide a substantially smooth outer surface for attaching conventional plug wrap without the need for an internal glue line. The external cavities comprise from about 5 to no more than 50 percent of the total outer surface of the inner filter member, preferably between about 20 to 30 percent. This enables the inner filter member to provide substantially uniform support to the overwrap. The outer cavities may be in the form of elongated, discrete, grooves, a knurled-like pattern or a continuous helical groove. The resultant filter has high filtration and correspondingly low pressure drop characteristics, with the technique of manufacture being such as to permit higher production speeds than with the prior art, resulting in lower manufacturing costs.

Abstract: Tobacco smoke filters wherein the products have an elongated hollow inner member overwrapped with a conventional plug wrap, with an intermediate member interposed therebetween. The intermediate member is comprised preferably of a filtering material different from that which forms the inner member so as to provide selective filtration through the two layers of filtering material, the intermediate member functioning to remove larger particles of undesirable material so that the interstitial spaces of the inner member are not clogged thereby. Moreover, the presence of the intermediate member provides a smooth outer surface for attaching a conventional plug wrap without the need for an internal glue line.

Abstract: An improved crimper assembly for use in making crimped filter materials is disclosed. The improved features of the assembly include an insulated central heater block which incorporates a steam entrance housing. Also provided are side plate bearing blocks which are insulated from the heater block. Other features include means for precision alignment and interchangeability of components.

Abstract: Tobacco smoke filters having a composite substantially cylindrical inner member formed from two semi-cylindrical inner elements and overwrapped with a common plug wrap. The composite inner member has a discrete inner cavity formed in each semi-cylindrical element and a composite cavity formed by a depressed portion in each semi-cylindrical element. A substantially smooth outer surface is provided on the composite inner member for attaching a conventional plug wrap without the need for an internal glue line. Separate cylindrical elements are reformed into semi-cylindrical elements and crimped to provide depressed pockets, following which the semi-cylindrical elements are mated and overwrapped to produce the final product.

Abstract: A circumference-measuring gauge comprising a tape curved over an intermediate portion into a closed loop with its two end portions extending away from the loop in opposite directions, two mounting members one fixed relative to each end portion of the tape and mounted for relative movement towards and away from one another to increase or decrease the loop circumference, and means responsive to the distance apart of two datum points one fixed relative to each mounting member to indicate the size of the loop.