US3590675A

US3590675A - Apparatus for and method of making filter rods for filter tip cigarettes

Info

Publication number: US3590675A
Authority: US
Inventors: Otto Kappeler; Siegfried Sudrow
Original assignee: Efka Werke Fritz Kiehn GmbH
Current assignee: Efka Werke Fritz Kiehn GmbH
Priority date: 1969-08-14
Filing date: 1969-08-14
Publication date: 1971-07-06
Anticipated expiration: 1988-07-06

Abstract

Filter rods for filter tip cigarettes are cut from tows of cellulose acetate fibers. The tows are placed coaxially in front of a jet emitting continuously or intermittently a stream of compressed air which drives the tows successively against a detent. When the forward end of a tow abuts against the detent a movable circular knife is brought into position to sever a segment of the two therefrom. The knife is mounted at a predetermined distance from the detent, so that the portions of the two which are separated by the action of the knife are of uniform and precisely controlled length. Retraction of the knife following the cutting operation and lateral transport of the cut segments permits the uncut tow to advance by the force of the airblast until it rests at its forward end against the detent, whereby the operation is repeated.

Description

United States Patent Inventors Otto Kappeler Trossingen; Siegfried Sudrow,/Bunzwangen, both of, Germany Appl. No. 850,072

Filed Aug. 14, 1969 Patented July 6, 197 l Assignee Efka-Werke Fritz Kiehn G.m.b.lll. Trosstngen, Germany APPARATUS FOR AND METHOD OF MAKING FILTER RODS FOR FILTER TIP CIGARETTES 6 Claims, 2 Drawing Figs.

Primary Examiner-1ames M. Meister A!!0rney Nolte and Nolte ABSTRACT: Filter rods for filter tip cigarettes are cut from tows of cellulose acetate fibers. The tows are placed coaxially in front of a jet emitting continuously or intermittently a stream of compressed air which drives the tows successively against a detent. When the forward end of a tow abuts against [1.5. [he detert a movable circular knife is brought into position to 33/160, 83/263, 33/281, 33/402, 83/417 sever a segment ofthe two therefrom. The knife is mounted at hit. a predetermined distance from the deter so that the portions Field of Search 83/98, l 12, f th tw which are eparated by the action fthe knife are of 269, 281, 402, 417 uniform and precisely controlled length. Retraction of the knife following the cutting operation and lateral transport of Rekrences Cm the cut segments permits the uncut tow to advance by the UNITED STATES PATENTS force of the airblast until it rests at its forward end against the 2,005,589 6/1935 McCoy 83/269 UX detent, whereby the operation is repeated.

e 2e o l 25 1 D 16 r 7" l7 2 a C O I 8 t r O r mr O O PATENTEU JUL 6 I97! INVENTORS. OTTO KAPPELER BY SIEGFRIED SUDROW %%1 jz@eez ATTORNEYS APPARATUS FOR AND METHOD OF MAKING FILTER RODS FOR FILTER TIP CIGARETTES The present invention relates to an apparatus for, and method of, making filter rods for filter tip cigarettes, and particularly for making filter rods which are segments of a longitudinal tow of smoke-filtering fibers.

It is essential in the manufacture of such filter rods to minimize the physical and temporal length of the supply path; this requirement, however, makes it difficult to precisely time the process and to control the length of the filter rods.

SUMMARY OF THE INVENTION It is, therefore, the primary object of the present invention to satisfy the respective requirements by providing a simple apparatus for, and method of, making filter rods for filter tip cigarettes which permit a precise measurement of the length of the individual filter rods.

This object and other which will become apparent hereinafter are attained, in accordance with the present invention, by aligning the tows in spaced relationship in front of, and coaxial with an air jet to which compressed air is supplied from a source. The forward propulsion of the tows under the force of the compressed airblast is arrested by detent means disposed at a predetermined distance from the air jet. Cutting means positioned intermediate the air jet and the detent are actuatable to sever the tows transversely of their length. The distance between the cutting means and the detend means precisely equals the desired length of the individual filter rods. In one preferred embodiment of the invention the cutting means is a circular crosscut knife executing one idling revolution after each cutting operation, whereby a special working rhythm is established during which uniform segments are successively cut from a tow without waste motions and without a waste of time.

According to a preferred embodiment, the detent means is formed by the outer wall of a sliding conveyor movable in a reciprocating manner in a direction perpendicular to the direction of the airblast. The conveyor is enclosed in a coaxial conduit. The wall of the conduit comprises, in the region ofair jet, an aperture through which the forward end of the tow is admitted to abut against the outer wall of the sliding conveyor. The conveyor includes a bore transversely its length and of substantially the same diameter as the aperture in the'conduit wall. The reciprocating movement of the conveyor is synchronized with the movement of transport means which place the tows into position relative to the knife, and with the operation of the knife, so that following the cutting operation the conveyor is in its initial position wherein the bore is aligned with the aperture in the conduit wall. During the alignment the cut segment of the tow, of precisely the same length as the final filter rod, is received in the bore and is subsequently transported therein to a precessing station. Removal of the cut segment out of the path of the airblast permits the uncut tow to advance, so that successively lengths of uniform filter rods are produced.

BRIEF DESCRIPTION OF THE DRAWING Filter rods for cigarette filters are commonly produced from substantially cylindrical tows comprising synthetic fibers, especially cellulose acetate fibers. The tows are cut into filter plugs or rods of predetermined length, which are inserted into filter tubes attached to tobacco-filled cigarettes and cemented therein.

In FIG. 1 there is shown a hopper 3 mounted on a rotatable drum 1 which is attached to a frame 20. The bottom section of hopper 3 comprises an open part 3a through which a portion of the drum 1 is admitted. Hopper 3 is adapted to hold a supply of cylindrical tows 2 of acetate fibers in substantially parallel alignment relative to one another. The drum I is mounted coaxially with a notched wheel I on shaft 2!. Rotation of the drum I in the direction of arrow A is actuated by means of a striker 22 which is supported in springs 23, and

which alternatingly engages and releases, by reciprocating motion, successive notches 24 on the periphery of wheel 1'. The springs 23 are alternatingly attracted and repulsed by a magnet ll" which is connected to a motor 27, and which is energized, respectively deenergized thereby, as is well known. The angle of striker 22 in respect to the notches 24 of wheel 1' is such that a forward stroke of the striker gives the wheel a forward push to angularly displace it by a distance which puts the following notch into position to receive another push in the indicated direction during the following forward movement ofthe striker.

In an alternate embodiment of the present invention, which is indicated diagrammatically in FIG. 1, the drum 1 is rotated by motor 27, the output shaft of which is linked by camming gear 28 of conventional construction to the drum. A tension spring 25 is provided intermediate the motor 27 and the drum 1; when an electric contact is close-d, the spring means 23 releases the drum by retraction of the striker 22, so that the drum 1 can rotate through the predetermined angle. In this embodiment the function of striker 22 is to arrest the movement of the drum by engagement of the notches 24 of wheel El.

Drum ll comprises on its circumference a plurality of symmetrically spaced U-shaped pockets 5. As the pockets 5 are moved successively through the hopper 3 by rotation of the drum 1, one tow 2 after the other is scooped up in the successive pockets and is transported therein along a rotary path toward a position P (FIG. 2) in front of and coaxial with a stream of compressed air which is supplied intermittently or continuously through a jet 6 by means not shown. At a predetermined distance from the jet 6 detent means for the tows 2 are provided by the other wall of a sliding conveyor 7 which is movable perpendicular to the airstream in the horizontal direction. A circular crosscut knife 8 is mounted on the frame 20 at a point intermediate the detent means, that is, the wall of conveyor 7 and the jet 6. The knife is rotatable in the direction of arrow C, and is mounted, controlled and actuated by means denoted by the

reference numerals

9, and 11 respectively which are not to be considered part of the present invention. In combination, these elements make it possible to reciprocate the knife in the direction of arrow D, so that, in synchronization with the rotation of drum 1 and with the sliding movement of conveyor 7, the knife is lowered into the path of the airstream, to cut a segment 14 from the two 2, and elevated away from the path and out of the way as a successive portion of tow is advanced by the airblast.

The conveyor 7 is encased in a conduit 12 which includes, in the region of the airstream, an aperture 13 through which the forward part of tow 2 is admitted to abut against the outer wall of conveyor 7 inside the conduit. The conveyor 7 comprises a bore 15 transverse to its length which, in the initial position of the conveyor is coaligned with aperture 13 in the conduit 12, and forms an opening in which the cut filter rod 14 is received as the airstream pushes against the tow 2 in the pocket 5. When the conveyor 7 slides forward under the influence of drive means, not shown, the filter rod 2 in the bore 15 is transported therein, and a closed portion of the wall of conveyor 7 is brought opposite the aperture 13 to form a detent for a succeeding portion of tow 2 prior to cutting.

A transport wheel 16 is mounted on the frame 20 parallel with drum l proximate to the longitudinal wall of conduit 12 opposite the wall which is facing the airstream. The wheel 16 which is rotatable on a shaft 26 comprises a plurality of tubular bores 17 which are equidistantly spaced in annular arrangement on its surface and extend parallel with shaft 26. During rotation of the wheel 16 (by means not shown) one of the bores 17 after the other is brought into position to commu nicate with the bore 15 of conveyor 7 when the latter is in its extreme forward or terminal position. A pin-shaped pusher 18 which is mounted on the frame 26 coaxiaily with the bores 17 and E5 in their coaligned position is reciprocated in the direction of arrow E (by means not shown), to push the filter rod M out of bore 15 into bore 17. The wheel I6 then carries the rod 14 through a rotary path of predetermined length to an ejection station 19 where the rod is removed and processed into a filter tube, as is well known.

The steps of the operation by which the filter rods are produced are as follows: drum 1 is driven by actuation of the notched wheel 1' through striker 23, respectively by energization of the magnet 1''. During rotation of the drum 1 tows 2 are deposited in the pockets 5 on the periphery of the drum and moved, one after the other, in front of an air jet 6. The force of compressed air emitted through the jet propels the tow in a forward direction until it passes through an aperture 13 in the wall of conduit 12 to abut against the outer wall ofa sliding conveyor 7 which is coaxially reciprocable in the interior of the conduit. Held in place thereby, the tow 2 is cut transversely ofits length by a circular knife 8 which is positioned at a location intermediate the jet 6 and the detent means provided by the wall of conveyor 7. The knife 8 is actuated by drive means 11 and controlled by means to sever a portion of predetermined length from the tow 2, proportional to the length of the final filter rod 14.

The length of the cut filter rod is independent of the length of the tow. As the sliding movement of the conveyor 7 aligns the bore in the conveyor with the aperture 13 in the conduit wall and with the direction of the airblast, the cut filter rod 14 is received in the interior of the conveyor 7 and laterally transported therein, so that a successive portion of the uncut tow is moved into the place previously occupied by the cut segment. The forward transport of the conveyor moves a portion of the wall of the conveyor 7 opposite the frontal part of the uncut tow 2 to form detent means therefor, prior to the cutting operation. In this way the process is repeated until a tow 2 has been separated into parts 14 of equal length. If any remnant of a tow should be left over it will be blown aside by the airblast; lengths of tow which are less than the specified length of the final filter rod cannot enter the bore 15 of the conveyor 7, since the bore is always occupied by a cut filter rod. The distance between the pocket 5 of the drum 1 and the detent means is precisely controlled, so that a portion of a tow which is shorter than the correct length will not be held in the required alignment relative to the knife.

Although preferred embodiments of the invention have been illustrated and described, many modifications thereof will be obvious to those skilled in the art. Accordingly, the invention should not be limited except as defined by the following claims.

What we claim is:

ll. An apparatus for making filter rods for filter tip cigarettes from longitudinal tows of smoke-filtering material comprising a frame, a hopper for said tows, a source of compressed air, means for injecting compressed air from said source along a straight path across said frame, transport means for collecting said tows from said hopper and moving the same from said hopper laterally in spaced relationship into said path and coaxial therewith, a conveyor adjacent to said transport means, detent means mounted on said frame limiting said path, cutting means attached to said frame and movable thereon between a first position away from and a second position into said path, for cutting segments of said tows therefrom transversely of their lengths, and said compressed air source propelling the cut segments of said tows on said conveyor.

2. An apparatus as defined in claim 1 wherein said cutting means is a crosscut circular knife positioned relative to said detent means at a distance which is proportional to the length of each ofsaid filter rods.

3. An apparatus as defined in claim 1 wherein said detent means is formed by said conveyor reciprocatingly slidable in a direction normal to said path of compressed air.

t. An apparatus as defined in claim 3 wherein said conveyor comprises a tubular bore extending therethrough transversely of its longitudinal axis, said tubular bore being adapted to receive a cut segment ofsaid tows.

5. An apparatus as defined in claim 4 further comprising a hollow conduitcoaxial with and enclosing said conveyor, said conduit comprising an aperture at a location opposite said source of compressed air and adapted to communicate with said bore in said conveyor only in the initial position thereof, wherein said out segments of said tows are received in said conveyor.

6. An apparatus as defined in claim I wherein said transport means is a rotatable drum having a plurality of spaced pockets on the circumference thereof for receiving said tows from the hopper.

Claims

1. An apparatus for making filter rods for filter tip cigarettes from longitudinal tows of smoke-filtering material comprising a frame, a hopper for said tows, a source of compressed air, means for injecting compressed air from said source along a straight path across said frame, transport means for collecting said tows from said hopper and moving the same from said hopper laterally in spaced relationship into said path and coaxial therewith, a conveyor adjacent to said transport means, detent means mounted on said frame limiting said path, cutting means attached to said frame and movable thereon between a first position away from and a second position into said path, for cutting segments of said tows therefrom transversely of their lengths, and said compressed air source propelling the cut segments of said tows on said conveyor.

2. An apparatus as defined in claim 1 wherein said cutting means is a crosscut circular knife positioned relative to said detent means at a distance which is proportional to the length of each of said filter rods.

4. An apparatus as defined in claim 3 wherein said conveyor comprises a tubular bore extending therethrough transversely of its longitudinal axis, said tubular bore being adapted to receive a cut segment of said tows.

5. An apparatus as defined in claim 4 further comprising a hollow conduit coaxial with and enclosing said conveyor, said conduit comprising an aperture at a location opposite said source of compressed air and adapted to communicate with said bore in said conveyor only in the initial position thereof, wherein said cut segments of said tows are received in said conveyor.

6. An apparatus as defined in claim 1 wherein said transport means is a rotatable drum having a plurality of spaced pockets on the circumference thereof for receiving said tows from the hopper.