Method, mechanism and apparatus for momentary compression of filter material

Abstract

A mechanism for a momentary compression of a filter material used in the tobacco industry, wrapped into a wrapper and glued with an adhesive delivered from an adhesive applying apparatus, adapted to being placed on a machine for manufacturing filter rods before the adhesive applying apparatus is characterised in that it comprises at least one rotary compressing member for pressing the filter material linearly moving underneath it. A method of a momentary compression of a filter material used in the tobacco industry, wrapped into a wrapper and glued with an adhesive delivered from an adhesive applying apparatus on a machine for manufacturing filter rods is characterised in that before wrapping the filter material into the wrapper the filter material is compressed by exerting a force on the filter material by at least one rotary compressing member.

Claims

1. A method for wrapping preformed rod-shaped filter segments (S) used in the tobacco industry into a wrapper, wherein the preformed rod-shaped filter segments (S) positioned on the wrapper (103) are travelling on a belt of a conveyor (102), the wrapper (103) being located lengthwise on the conveyor (102), the method characterized by the following steps: forming the wrapper (14) into a U-shape, momentarily compressing the preformed rod-shaped filter segments (S) by means of at least one rotary compressing member (10) exerting a force (F) on the preformed rod-shaped filter segments (S) located in the U-shaped wrapper (14), the U-shaped wrapper having an edge, wherein the at least one rotary compressing member (10) is situated above the travelling preformed rod-shaped filter segments (S) and the force (F) is directed in a vertical direction (V) or at an angle (β) relative to the vertical direction (V), forming the U-shaped wrapper (14) into a cylindrical sleeve around the compressed preformed rod-shaped filter segments (S) by delivering glue from an adhesive applying apparatus on the edge (15) of the U-shaped wrapper (14), yielding a fully closed cylindrical wrapper, allowing the compression of the preformed rod-shaped filter segments (S) to cease after the fully closed cylindrical wrapper has been formed, such that space inside the fully closed cylindrical wrapper (14) is filled with at least one preformed rod-shaped filter segment (S).

2. The method as in claim 1 wherein the compression of each preformed rod-shaped filter segment (S) is carried out gradually by means of a series of multiple rotary compressing members (10), each of the multiple rotary compressing members acting on the compressed preformed rod-shaped filter segment (S) with a different force (F).

3. The method as in claim 2 wherein the force (F) exerted by successive rotary compressing members (10) on the compressed rod-shaped filter segment (S) increases.

4. The method as in claim 1 wherein the force (F) is directed at an angle (β) in the range of 5° to and 30°.

5. The method as in claim 4 wherein the angle (β) is in the range of 15° to 20°.

6. A device for wrapping a preformed rod-shaped filter segment (S) used in the tobacco industry into a wrapper, comprising: a belt conveyor (102) for transferring the preformed rod-shaped filter segments (S) positioned on the wrapper (103), wherein the wrapper (103) is formed into a U-shaped wrapper (14), an adhesive applying apparatus (104) for delivering glue on the edge of the U-shaped wrapper (14), a heater (105) adapted to heat up adhesive so that fully closed cylindrical sleeve of the wrapper (14) is formed, and a momentary compressing mechanism (11, 11′) arranged before the adhesive applying apparatus (104) and comprising at least one rotary compressing member (10) excreting a force (F) on the preformed rod-shaped filter segment (S) located in the U-shaped wrapper (14), wherein rotary compressing member (10) is situated above the travelling preformed rod-shaped filter segment (S) and wherein the momentarily compressing mechanism (11, 11′) is adapted to adjust the force (F) so that the force (F) is directed in a vertical direction V or at an angle βrelative to the vertical direction V to allow decompression of the preformed rod-shaped filter segment (S) to end to end after forming the cylindrical sleeve of the wrapper (14).

7. The device as in claim 6, wherein it comprises two rotary compressing members (10).

8. The device as in claim 7 wherein the last rotary compressing member (10A), considering the direction of movement of the preformed rod-shaped filter segments (S), has a smaller working width than the preceding compressing members (10).

9. The device as in claim 6, wherein it comprises three rotary compressing members (10).

10. The device as in claim 6 wherein rotary compressing members (10) have different diameters and a compression line (13) defined by the lowest points of rotary compressing members (10) is inclined relative to an axis (SA) of the preformed rod-shaped filter segment (S) an angle (α) between 1° and 5°.

11. The device as in claim 10 wherein the inclination is between 2° and 3°.

12. The device as in claim 6 wherein the rotary compressing member (10) is a compressing roller with a cylindrical working surface (20).

13. The device as in claim 6 wherein the rotary compressing member (10) is a compressing roller with a conical working surface (20).

14. The device as in claim 6 wherein the rotary compressing member (10) is a compressing roller with an oval working surface (20).

Description

DESCRIPTION OF THE DRAWING

(1) The invention is explained in a drawing in which:

(2) FIG. 1 diagrammatically shows a fragment of a machine for manufacturing multi-segment rods,

(3) FIG. 2 shows a compressing mechanism in a front view,

(4) FIG. 3 shows a compressing mechanism in a top view,

(5) FIG. 4 shows an embodiment of a rotary compressing member,

(6) FIG. 5 shows another embodiment of a rotary compressing member,

(7) FIG. 6 shows another embodiment of a rotary compressing member,

(8) FIG. 7 shows a section of a continuous filter rod during material decompression,

(9) FIG. 8 shows a section of a continuous filter rod after material decompression,

(10) FIG. 9 shows an alternative embodiment of the compressing mechanism,

DETAILED DESCRIPTION

(11) FIG. 1 diagrammatically shows a fragment of a machine for manufacturing multi-segment rods. A delivery unit 101 delivers filter segments S prepared in a known way onto a conveyor 102, whereas onto its surface a wrapper 103 is placed. During the transfer of segments on the conveyor 102 the wrapper 103 is wrapped in a known way around the segments and glued, whereas the adhesive is delivered from an adhesive applying apparatus 104 and an adhesive seam is heated up by a heater 105. A multi-segment continuous rod CR formed in such a way is transferred further and is cut into filter rods FR by means of a known cutting head 106 provided with knives 107. Typical members supporting and guiding the endless rod CR and the filter rods FR were omitted in the drawing.

(12) An apparatus for a momentary compression of the filter material constitutes a part of a machine for manufacturing rods of the filter material. It comprises members for guiding the wrapper and the filter material, and a compressing mechanism 11 a fragment of which was shown in FIG. 2. The compressing mechanism 11 is situated above the moving filter material, for example in the form of segments S, whereas the wrapper into which the segments are wrapped was not shown. An example mechanism comprises three rotary compressing members 10 situated one after another, whereas in the embodiment shown the centres of the compressing members 10 lying on the axes of rotation T of the compressing members are situated on one line 12. Through the lowest positioned points, which press the material to the highest degree, a compression line 13 on the circumferential surfaces of the rotary members 10 was drawn. For the rotary members 10 with equal diameters the compression line 13 will be parallel to a line 12 going through the centres of the rotary members 10. The rotary members 10 can have different diameters, whereas the compression line defined by the lowest positioned points can be inclined relative to the axis SA of the filter material S at an angle α between 1° and 5°, preferably the inclination is between 2° and 3° depending on the filter material. An inclination of the compression line ensures that successive rotary compressing members 10 act on the filter material with an increased force. If different diameters of the rotary members 10 are used, the compression line 13 is a broken line.

(13) FIG. 3 shows a compressing mechanism 11 for a momentary compression of the filter material in a top view. A wrapper 14 into which the segments S are wrapped can be seen here, whereas its edges were marked with the markings 15 and 16. Also an adhesive nozzle 17 of an adhesive applying apparatus, from which the adhesive is delivered onto the wrapper 14 on the edge 15, is shown in simplified representation. Three rotary compressing members 10 can be seen in the compressing mechanism 11 shown, whereas the last rotary compressing member 10A has a smaller width g2 than a width g1 of the preceding compressing members 10. The rotary compressing members 10, 10A are rotatably mounted in a body 18 by means of bearings 19. The rotary compressing members are set in rotational motion by the filter material. A torque coming from the forces of friction between the filter material and the surface of compressing members acts on each of the compressing members. However, a solution is also possible wherein they are driven by a separate drive mechanically or electronically synchronised with the drive of the conveyor 102 (FIG. 1) so that no slide between the circumferential surface of the rotary members 10 and the surface of the filter material S occurs.

(14) The embodiments of rotary compressing members are described below. A rotary compressing member 10′ rotating around the axis T shown in FIG. 4 has a circumferential surface 20 in the cylindrical form and during the operation of the mechanism exerts a force F on a continuous or segmental filter material S partly wrapped into the wrapper 14, whereas the force F is directed in a vertical direction V and causes horizontal depression of the filter material. The rotary compressing member 10″ rotating around the axis T shown in FIG. 5 has a circumferential surface 21 in the conical form and during the operation exerts a force F′ on the continuous or segmental filter material S partly wrapped into the wrapper 14, whereas the force F′ is directed at an angle β to the vertical direction V and causes inclined depression on the surface of the filter material. Preferably the angle β is between 5° and 30°. Conducted tests showed that even more preferably the angle β amounts between 15° and 20°. A rotary compressing member 10″′ rotating around the axis T shown in FIG. 6 has an oval circumferential surface 22 and during the operation exerts a force F″ on a continuous or segmental filter material S partly wrapped into the wrapper 14, whereas the force F″ is directed at an angle β to the vertical direction V and causes inclined concave depression of the filter material.

(15) The position of the compressing mechanism can be selected according to the filter material and the manufacturer's requirements. The position of the compressing mechanism can be determined in a typical way in the directions of three axes X, Y and Z (FIGS. 2 and 3). In addition, the angular position of the compressing mechanism can be determined so as to select the value of the angle α of the compression line of the mechanism relative to the axis of the filter material according to the kind of the filter material.

(16) During the manufacture of filter rods FR, before gluing the wrapper 14, the filter material S in the form of segments or in the continuous form is compressed by means of the compressing mechanism 11 in order to reduce the cross-section of the filter material. The depression and the reduction of the cross-section caused by the compression makes it possible that wrapping of the wrapper in order to obtain a cylindrical sleeve around the filter material takes place without the need of a simultaneous compression of the wrapped material. The wrapper is formed in the cylindrical shape and is glued. A decompression takes place during the wrapping and it finally ends after forming a sleeve of the wrapper. FIG. 7 shows a section of an endless filter rod during the decompression of the filter material S; a certain space P not yet filled with the filter material exists within the endless rod section, whereas the wrapper has already been formed, and the adhesive seam G has already been made. FIG. 8 shows a section of an endless filter rod after the decompression of the filter material S.

(17) A compressing mechanism 11′ according to the invention can also be embodied using an intermediate pressing member 25 (FIG. 9) between the rotary compressing members 10 and the filter material S, for example in the form of a strip or a tape. The working surface of the intermediate pressing member 25 can be shaped in any way. The use of an intermediate pressing member does not influence the effectiveness of operation of the mechanism according to the invention.

(18) An advantage of the method according to the invention is that the final decompression of the filter material takes place after forming and gluing the wrapper, which allows obtaining better filling of the wrapper.