US3370514A - Manufacture of cigarette filters - Google Patents

Description

Feb. 27, 1968 M. D.l x.. ROME MANUFACTURE OF CIGARETTE. FILTERS 2 Sheeis-Sheet l Filed May 28, 1965 HHHII lilllllllllll IHII PMN Hlm Hummm FIGB MATTI/sw .DAV/p Eh/1.: EaME Feb. 27, 1968 Filed May 28, 1965 M. D. L. ROME MANUFACTURE OF CIGARETTE FILTERS 2 Sheets-Sheet 2 United States Patent 3,370,514 MANUFACTURE F. CIGARETTE FILTERS Matthew David Lewis Rome, Gresswold, Johannesburg, Transvaal, Republic of South Africa, assignor to Brown & Williamson Tobacco Corporation, Louisville, Ky., a corporation of Delaware Filed May 28, 1965, Ser. No. 459,671 Claims priority, application Great Britain, May 29, 1964, 22,389/ 64 Claims. (Cl. 931) ABSTRACT 0F THE DISCLGSURE Apparatus for manufacturing multiple tobacco smoke filters comprising an Iassembly having means for feeding quantities of particles of particulate material and means for feeding lengths of filte-r plug material to an assembly point so that both materials are combined in vertical superimposition and means for wrapping the superimposed materials in a wrapper to form a continuous rod.

This invention concerns improvements relating to the manufacture of multiple cigarette-smoke filters.

It is known to make such filters from two or more sections of different filtering materials, using a modified form of conventional cigarette making machine. Shutiling means arrange the sections of different materials in the appropriate order and the sections are then aligned and wrapped on the horizontal moving band of the machine. This procedure is satisfactory for the assembly of sections of materials which are capable by themselves of sustaining a required form, such as fibrous or sheet material which has been wrapped or sealed on the surface so as to retain a substantially cylindrical shape. However, it may be desirable to incorporate into a multiple filter one or more sections of filtering material in the form of loose powder or granules. The manufacture of these filters requires the accurate measurement of a substantially constant amount of the loose material into a space or spaces, usually between filter sections of self-sustaining material, and subsequent envelopment of the sections in an outer wrapper to form a coherent multiple-section rod. This may involve considerable difficulties both as to the consistent feeding of the loose material and as to its even packing into the spaces. Consequently the modified cigarette-making machine must be operated at a considerably slower rate than is possible when only self-sustaining sections have to be assembled.

An object of the present invention is to make it possible to produce quickly and conveniently multiple filters incorporating sections containing powdered or granular material capable of filtering cigarette smoke, for exa-mple charcoal, silica gel, zeolites or activated alumina and sections consisting of filter plugs made, for example, of cellulose acetate, viscose or polyolefin fibres or of sheet material such as paper.

According to the invention, apparatus for the purpose set forth comprises means for feeding quantities of powdered or granular filter material and lengths of filterplug material to an assembly point and means operative at the said point for combining the said quantities and lengths in vertical superimposition. Advantageously, successive assemblies are carried away from the assembly point in rod form, with which object they may be wrapped after leaving the said point. A continuous rod thus produced may then be passed through sealing and forming devices to cut-off means. The feed means may operate by gravity alone or may be pneumatically assisted.

Such apparatus has the advantage that, with vertical superimposition ofthe materials, the powdered or granular material can be evenly distributed over a plane perice pendicular to the longitudinal axis of the assembly or rod which is produced. Also the plug material can be caused to come to bear firmly upon the sections or beds of powdered or granular material, holding them vin the evenly distributed state during subsequent wrapping and sealing.

Examples of ways of carrying the invention into effect will now be more fully described with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of one form of apparatus for producing multiple filters,

FIGURE 2 is a vertical section on the line II-II in FIGURE 1.

FIGURE 3 is a plan view of the apparatus, and

FIGURE 4 is a perspective view of another form of apparatus.

The form of apparatus illustrated in FIGURES l to 3 comprises upper and lower feed wheels 1, 2 rotatable about vertical axes 3, 4 respectively. The upper wheel 1 is perforated ne-ar its periphery with holes 5 adapted for receiving double-lengths of filter-plug material and holding them vertically, i.e. with their longitudinal axes perpendicular to the plane of the wheel 1. The wheel 2, disposed immediately below the Wheel 1, is of larger diameter and is similarly perforated with holes 6 each adapted for receiving a measured quantity of powdered or granular material or for itself measuring out the said quantity. Suitably the grain size of this material is between 10 and 40 British Standard mesh, but finer material can be employed. The axes 3, 4 are offset in relation to each other, but so that the upper wheel 1 falls within the lower wheel 2 as seen in plan View (FIG. 3) and that the holes 5, 6 in the upper and lower wheels 1, 2 coincide at only one point 7, where assembly occurs. The wheels 1, 2 are driven in the same direction through a common gear wheel 8 meshing with teeth 9, 10 at the peripheries of the respective wheels. Plug lengths are fed into the holes v5 in the upper wheel 1 from supply means which is shown as a pneumatic-conveyor tube 11, but may be a hopper. The powdered or granular material is supplied from a hopper 12 to the holes 6 in the wheel 2, at a point where it is not overlaid by the wheel 1. With the arrangement illustrated, the holes 6 themselves serve to measure out the required quantities of material. If preferred, however, additional means may be provided for feeding accurately measured quantities to the holes 6. Fixed underneath the wheel 2 and extending, at least, from the hopper 12 to the assembly point 7 is a retaining plate 13 of sufiicient width to close the lower ends of the holes 6 in the wheel 2, except at the point 7, Where the plate 13 is likewise provided with a hole 14 (FIG.4 2). A tube 15 with an internal diameter slightly larger than the diameter required for the finished filter rod is attached by a boss to the plate 13 in vertical alignment with the hole 14 and with the point 7 of coincidence of the holes 5, 6 in the wheels 1, 2. Preferably and as shown, Van air nozzle 16 is arranged above the point 7 to provide an air jet for assisting transfer of the filter assemblies into the tube 15.

Wrapping-paper strip 17 from a reel passes over a roller 18 into a funnel-shaped guide 19 which leads it around the reduced and obliquely terminated lower end 20 of the tube 15, where it becomes wrapped tightly around each emerging assembly with the assistance of a guide 21.

For the example illustrated, it is to be assumed that the paper strip 17 is coated with a heat-seal composition. To seal the strip around the assembly as it emerges from the guide 21, it is passed through a vertically disposed heater 22 which may be an electrical seam heater such as is used in conventional cigarette-making machines. Beyond the heater 22, the wrapped assembly now in the of 0.318 inch and was provided withV six longitudinal form of a continuous rod, is carried, with the assistance of a garniture tape 23, through a conventional garniture 24. ln addition to bringing the rod to its final circular form and required diameter, the garniture thus serves to draw the rod through the machine, the paper strip 1'.' being freely running and not itself driven. Difiiculties due to slip can be avoided in this manner. Beyond the garniture 24, the rod is cut at 25 into lengths suitable for subsequent sub-division into individual triple filters for incorporation in cigarettes. ln the individual filter7 a section f powdered or granular material remains held, within the wrapping, between single-length sections of plug material. The cutting is effected by a conventional cut-off device comprising knives operating in a horizontal plane.

` Instead of using heat-seal paper, a plain paper strip 17 may be pasted or glued in the apparatus. In this case, a pasting wheel is arranged to apply paste to the overlapping edges of the strip 17 immediately before it is completely closed to form a wrapping. If desired, an inlet may be arranged to communicate with the inside of the tube 15 to allow paste to be applied to the filter materials before wrapping in order to assist in sealing the materials to the strip. The continuous rod then passes through a vertically disposed seam heater and is cut into lengths, as described above. The rod may be driven by means of successive rubber feed rollers and the paper strip 17 may itself also be driven by geared feed rollers.

With the alternative form of apparatus shown in FIG- Y URE 4, filter-plug lengths 26 are Ifed in vertical align ement from a pneumatic tube 11 to a point 27 adjacent to the assembly point '7 on the upper surface of the wheel 2 for supplying the measured quantity of powdered or granular material. The wheel 2 is rotated intermittently, through one pitch of the holes 6 at a time, by a drive i controlled by. an indexing unit. Two push rods 28, 29, operating in timed relation with the intermittent move-` ment of the wheel 2, are arranged to bring each plug length 26 into position. One push rod 28, operating substantially parallel to a diameter of the wheel 2, moves the plug length from below the tube 11 to a position co-axial with the hole 6 at the assembly point 7 and with the hole 14 (not seen) in the plate 13, vwhile the other push rod 29, operating vertically from above the said point, ensures both close contact between each plug 26 and the powdered or granular material in the hole 6 and complete transfer of the plug length and powdered or granular material into a tube similar to the tube 15 of the apparatus of FIGS. 1 to 3. The rod thus formed is then wrapped and sealed and cut up as described above. As illustrated, the push rod 28 operates radially of the wheel 2, but it could be arranged to operate tangentially.

A specic example for the production of triple filters ina form of apparatus such as is shown in FIGS. 1 to 3 will now bedescribedz- Plug material in rod form made from cellulose acetate fibres of Y- shaped cross-section, of filament denier 8.

and of total denier 51,000, were cut into 15 mm. lengths of 24.7 mm. circumference by a conventional cutting device. The plug lengths were fed pneumatically through a plastic tube 11 of 3/8 inch bore using an air pressure of lbs. per sq. in. The rate of feed was 1650 plug lengths per minute. The tube 11 ended in an injector head of 0.315 inch internal diameter, from which the said lengths were blown into the holes 5 in the wheel 1. Charcoal granules of 12-16 British Standard mesh (Pittsburgh Activated Carbon Co., Grade BPL) were fed from the hopper 12 to the holes 6 in the wheel 2. For this example, the wheels 1, 2 were 15 mm. and 5 mm. thick respectively.

A perforated brass disc rotating between the nozzle 16 and the upper wheel 1 was arranged to act as a valve so that the air-jet, supplied at 60 lbs. per sq. inch, only H functioned when holes 5 and 6 were aligned over the hole 14V and tube 15. The tube 15 hady an internal diameter slits to allow the air to escape.

The paper 17 was polyethylene coated paper 0.003 inch thick and 27 mm. wide. The heater 22 was 3.5 inches long and of 0.315 inchinternal diameteLrThe garniture 24 was 10l inches long and designed toproduce filters of 25 mm. circumference. The rod produced was-cut through each six plug length to givey a rod length comprising six triple filters each with end sections, 7.5 mm. long, of cellulose acetate and a middle section, 5 mm. long, of carbon granules.V y l The dimensions of the wheels 1 and 2 can be selected to suit requirements. Thus, their diameters can be increased if higher production speeds are required. Their thicknesses will depend upon the lengths of the respective sections of the different materials. Moreover, the apparatus is not confined to the production of triple ilters such as have been referred to above'. By modifying the feeding system and the spacing of the holes in the wheels 1 and 2, it is possible to produce filters comprising, Say, three short plug lengths and two narrow sections of powdered or granular material or a thin waferyof the latter material between two retaining plugs.

If desired, the holes 5 in the wheel 1 may be arranged to taper downwardly, from the upper end to a short distance from the lower end, in orderto facilitate entry of the plug lengths. rl`his taper. may also be increased by displacing the leading edge of the upper end ofthe hole in theV direction of rotation of the wheely 1, so`

that the upper end of the hole is bounded by two semicircular portions joined by short straight portions. For example, with a hole 0.585 inch deep and having a diameter at its circular lower end of 0.320 inch, the hole may taper from 0.335 inch at the upper end to within 0.125 of the lower end. In addition, the leading edge may be displaced by 0.050 inch in the direction of rotation. Y

i claim: f

1. Apparatus for the manufacture of multiple cigarettesmoke filters comprising: a supply device for particles of particulate ilter material, a supply device for lengths of lter plug material, means for feeding quantities of said particulate material to an assembly point,means for feeding a length of said filter plug material to said assembly point and means operative at said point for combining said particles and lengths of filter plug material in vertical superimposition.

2. Apparatus as claimed in claiml and comprising assembly-guiding means whereby successive assemblies are carried away from said assembly point in rod form.

3. Apparatus as claimed in `claim 1 and comprising enrobing means for wrapping said assemblies in arpaperV strip and sealing and forming devices for forming a comV tinuous rod from said enrobed assemblies.

5. Apparatus as claimed in claim 1, comprising enrob ing means for-wrapping said assemblies in a paper strip and sealing and forming devices for forming a continuous rod from said enrobed assemblies, including a garniture device provided with a driven tape for applying traction Vto said rod.

6. Apparatus as claimed in claim 1,- comprising enrobing means for wrapping said assemblies in a paper strip, sealingl and forming devices for forming a continuous rod from said enrobed assemblies and cut-olf means, through which said rodis iinally passed, for dividing it into lengths.

7. A`method of manufacturing aV multiple cigarette'- sm'oke filter comprising: feeding particles of particulate filter material from a supply device, feeding lengths of filter plug material from a supply device, moving said particulate material andsaid filter material to an assembly point Vso as to combine both materials in vertical supen imposition and then wrapping the vertically superimposed materials to form a continuous rod.

8. Apparatus for the manufacture of multiple cigarettesmoke filters, comprising: means for feeding quantities of particles of particulate lter material and lengths of lter plug material to an assembly point, said means including a supply device for said particulate material, a rotatable horizontal wheel having a ring of holes forming pockets and positioned in relation to said supply device and said assembly point for receiving successive quantities of said particulate material in said pockets and conveying them therein to said assembly point and a surface closing the lower ends of said holes except at said point and means operative at said point for combining said quantities and lengths in vertical superimposition.

9. Apparatus for the manufacture of multiple cigarettesmoke filters, comprising: means for feeding quantities of particles of particulate iilter material and lengths of filter plug material to an assembly point, said means including a supply device for said particulate material, a rotatable horizontal Wheel having a ring of holes forming pockets and positioned in relation to said supply device and said assembly point for receiving successive quantities of said particulate material in said pockets and conveying them therein to said assembly point, a supply device for said lengths of filter plug material, a second, smaller, rotatable horizontal Wheel having a ring of holes forming pockets and positioned above the iirst named wheel in relation to the second named supply device and said assembly point for receiving successive lengths of said plug material in said pockets and conveying them therein to said assembly point, the two Wheels having their axes odset in such a manner that their said holes coincide at said assembly point only, means for driving said wheels so that the formed pockets in each Wheel pass said point at substantially the same speed and a surface closing the lower ends of said holes in the irst named Wheel except at said assembly point, and means operative at said point for combining said quantities and lengths in vertical superimposition.

l. Apparatus for the manufacture of multiple cigarette-Smoke lters, comprising: means for feeding quantities of particles of particulate filter material and lengths of iilter plug material to an assembly point, said means including a supply device for said particulate material, a rotatable horizontal wheel having a ring of holes forming pockets and positioned in relation to said supply device and said assembly point for receiving successive quantities of said particulate material in said pockets and conveying them therein to said assembly point, a supply device for said lengths of lter plug material, a pushing device operating in a direction .parallel to said Wheel for feeding successive said lengths to said assembly point and a pushing device operating in a direction perpendicular to said wheel for assembling said lengths with respect to said quantities and means operative at said point for combining said quantities and lengths in Vertical superimposition.

Reierences Cited UNlTED STATES PATENTS 3,259,029 7/1966 Hall et al 131-94 3,308,832 3/1967 Stelzer et al. 131-94 3,312,151 4/1967 Molins 131-94 GERALD A. DOST, Primary Examiner.

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