U.S. patent application number 11/375019 was filed with the patent office on 2006-09-21 for detection of non-homogeneities in a continuous filter rod.
This patent application is currently assigned to Hauni Maschinenbau AG. Invention is credited to Siegfried Hapke, Karsten Meins.
Application Number | 20060207616 11/375019 |
Document ID | / |
Family ID | 36579371 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060207616 |
Kind Code |
A1 |
Hapke; Siegfried ; et
al. |
September 21, 2006 |
Detection of non-homogeneities in a continuous filter rod
Abstract
A device for detecting isolated occlusions in a conveyed
continuous rod in the tobacco industry includes a light source for
irradiating the continuous rod with the aid of a light-transmission
method. A sensor is disposed for at least partially detecting
brightness caused by the light source being transmitted in the
continuous rod. An evaluation unit detects the presence of isolated
occlusions in the continuous rod on the basis of the detected
brightness.
Inventors: |
Hapke; Siegfried;
(Geesthacht, DE) ; Meins; Karsten; (Lauenburg,
DE) |
Correspondence
Address: |
VENABLE LLP
P.O. BOX 34385
WASHINGTON
DC
20045-9998
US
|
Assignee: |
Hauni Maschinenbau AG
Hamburg
DE
|
Family ID: |
36579371 |
Appl. No.: |
11/375019 |
Filed: |
March 15, 2006 |
Current U.S.
Class: |
131/280 |
Current CPC
Class: |
A24D 3/0295 20130101;
A24C 5/3412 20130101; G01N 2021/8925 20130101; G01N 21/89
20130101 |
Class at
Publication: |
131/280 |
International
Class: |
A24C 5/34 20060101
A24C005/34 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 17, 2005 |
DE |
10 2005 012 811.4 |
Claims
1. A device for detecting isolated occlusions in a conveyed
continuous rod in the tobacco industry, said device comprising: a
light source for irradiating the continuous rod via a
light-transmission method with a beam of light; a sensor for
receiving the beam of light transmitted through the continuous rod
and at least partially detecting areas of brightness caused by
irradiation from the light sources in the continuous rod; and an
evaluation device for detecting the presence of the isolated
occlusions in the continuous rod by evaluating the detected areas
of brightness.
2. The device as defined in claim 1, further comprising an imaging
device disposed between the continuous rod and the sensor where the
imaging device focuses the areas of brightness caused in the
continuous rod on the sensor.
3. The device as defined in claim 2, wherein the imaging device is
provided with at least one optical lens.
4. The device as defined in claim 2, wherein the light source
disposed on one side of the continuous rod, the imaging device
disposed on the opposite side of the continuous rod, and the sensor
that receives light from the imaging device constitute a measuring
device.
5. The device as defined in claim 4, wherein at least two measuring
devices are used to measure the continuous rod.
6. The device as defined in claim 5, wherein the at least two
measuring devices are arranged transverse to the longitudinal axis
of the continuous rod.
7. The device as defined in claim 1, wherein the light source
comprise a laser light source.
8. The device as defined in claim 2, further comprising at least
one diaphragm disposed in a path of the light beam between the
imaging device and the sensor.
9. The device as defined in claim 1, wherein the conveyed
continuous rod is a continuous filter rod.
10. The device as defined in claim 6, wherein the at least two
measuring devices are arranged in a single plane.
11. A continuous rod-producing machine used in the tobacco
industry, including the device as defined in claim 1.
12. A method for detecting isolated occlusions in a conveyed
continuous rod in the tobacco industry comprising the steps of:
irradiating the continuous rod with a light source using a
light-transmission method; at least partially detecting brightness
caused by the light source in the irradiated rod with a sensor; and
determining the presence of isolated occlusions in the continuous
rod on the basis of the detected brightness.
13. The method as defined in claim 12, including imaging, at least
in part, the brightness on the sensor by an imaging device.
14. The method as defined in claim 12, wherein the irradiating step
includes irradiating the continuous rod by a laser light
source.
15. The method as defined in claim 12, wherein the irradiating step
includes irradiating the continuous rod by at least two laser light
sources.
16. The method as defined in claim 12, wherein the irradiating step
includes irradiating the number of occlusions the locations of the
occlusion via the detected brightness.
17. The method as defined in claim 12, including removing at least
a section of the continuous rod if values for the detected
brightness deviate from predetermined control values.
18. The method as defined in claim 12, wherein the determining step
includes detecting the presence of occlusions in the continuous rod
via an evaluation unit.
19. A method of producing a continuous rod in a machine used in the
tobacco industry, comprising utilizing the device according to
claim 1 to detect isolated occlusions in the continuous rod as it
is conveyed in the machine.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of German Application
No. 10 2005 012 811.4, filed on Mar. 17, 2005, the subject matter
of which is incorporated herein by reference. Each U.S. and foreign
patent and patent application mentioned below is also incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a device for detecting isolated
occlusions in a conveyed continuous rod in the tobacco industry, in
particular in a continuous filter rod, wherein a light source
illuminates the continuous rod by a light-transmission method. A
sensor at least partially detects areas of brightness in the
continuous rod, caused by the light source.
[0003] The invention furthermore relates to a method for detecting
isolated occlusions in a conveyed continuous rod in the tobacco
industry, in particular a continuous filter rod. The continuous rod
is irradiated by a light source and wherein the brightness in the
continuous rod caused by the light source irradiation is at least
partially detected with the aid of a sensor.
[0004] The invention furthermore relates to a continuous
rod-producing machine in the tobacco industry, in particular a
filter-rod maker.
[0005] A known method for testing a conveyed continuously advancing
rod, in particular a continuous cigarette filter rod, is described
in unexamined published patent application DE-A-27 32 520. The '520
application describes sections containing different types of
material and/or differently embodied sections that follow
successively and continuously. In this known method, a light beam
extending nearly perpendicular to the plane for the longitudinal
axis of the continuous filter rod is introduced at one location
into the filter rod, and the brightness value measured at a
distance thereto by means of a photo-electronic component, meaning
at a location on the continuous filter-rod outside which is at
least nearly in the same plane as the one for the light ray. The
measuring result is then evaluated in an evaluation circuit that is
electrically connected to the photo-electronic component.
[0006] A device for testing multi-component cigarette filters
during the manufacturing process, following the continuous
attachment of filter elements in a tube-shaped wrapper, is
furthermore disclosed in U.S. Pat. No. 4,001,579 which corresponds
to patent document DE-C-25 10 502.
SUMMARY OF THE INVENTION
[0007] Starting with the above-mentioned prior art, it is an object
of the present invention to detect capsules or similar items
purposely inserted into a continuous transverse axial conveyed
filter rod.
[0008] The above and other objects are achieved according to an
exemplary embodiment of the invention in which there is provided a
device for detecting isolated occlusions in a conveyed continuous
rod in the tobacco industry, in particular a continuous filter rod,
comprising: a light source for irradiating the continuous rod by a
light-transmission method, a sensor for at least partially
detecting areas of brightness caused by irradiation from the light
source, and an evaluation unit for detecting the presence of
isolated occlusions in the continuous rod based on the detected
areas of brightness.
[0009] During the production of continuous filter rods,
non-homogeneities or occlusions, for example in the form of added
bodies such as flakes or capsules but also in the form of holes,
are inserted and/or generated either purposely or isolated in the
otherwise homogeneously embodied continuous filter rods. The
invention is designed to determine the existence of the
non-homogeneities or occlusions, as well as the correct location
therein in a continuous filter rod and/or in an individual filter,
and to evaluate these by the device according to the invention. The
distance between the occlusions as seen in the longitudinal axial
direction and/or the conveying direction for the continuous rod can
furthermore also be detected. For this, the conveyed continuous
filter rod is irradiated and a photodiode is used to receive the
light which passes through the continuous filter rod and/or the
corresponding brightness profile. Following this, the brightness
profile is used to determine whether the continuous filter rod
contains a non-homogeneous area.
[0010] According to an embodiment of the invention, the speed for
conveying the continuous filter rod can furthermore be used to
detect the spacing in the longitudinal axial direction between the
non-homogeneities. The detection according to the invention may
also determine the dimensions of the occlusion and/or the
non-homogeneous area with the aid of the continuously detected
brightness profiles and the conveying speed for the continuous rod.
This is achieved in another aspect of the invention by using an
evaluation unit to which the signals and/or the detected brightness
profiles from the sensor are transmitted.
[0011] It is furthermore advantageous if an imaging device is
provided for imaging the brightness of the continuous rod on the
sensor. As a result of this measure, the opening angle for the
receiving optic is minimized and an imaging optic and/or device is
used on the receiver side. For example, a smaller area of
brightness in the continuous rod and/or the brightness profile,
caused by the light source, is detected on a photo-sensitive layer
of a photo-sensor.
[0012] The imaging device is advantageously provided with at least
one lens and is thus embodied as an optical device.
[0013] It is furthermore advantageous if a measuring device is
constituted by the light source, imaging device, and sensor.
According to another exemplary embodiment at least two of such
measuring devices are provided for the continuous rod. In
particular, the at least two measuring devices are arranged
transverse to the longitudinal axis of the continuous rod,
preferably in a single plane.
[0014] A light propagation cone for the light emitted by the light
source is minimized in the continuous filter rod if the light
source is embodied as a laser light source, so that the continuous
filter rod and/or the rod-shaped article to be examined, which is
conveyed in longitudinal axial direction, is admitted with
fan-shaped or point-shaped light. The detection quality is improved
with a reduced light propagation cone in the continuous rod. The
continuous filter rod is preferably irradiated by a laser which
emits light in the red visible range, wherein laser light of this
type typically has a wavelength in the range of 655 nm.
[0015] At least one diaphragm is furthermore provided in the beam
path between the imaging device and the sensor.
[0016] According to another aspect of the invention, there is
provided a continuous rod-producing machine in the tobacco
industry, in particular a filter production machine and/or a filter
rod maker, equipped with a device according to the invention for
detecting isolated occlusions in a conveyed continuous rod in the
tobacco industry. To avoid repetition, the preceding explanation
concerning the device for detecting isolated occlusions is
expressly referred to.
[0017] According to yet another exemplary embodiment of the
invention, there is provided a method for detecting isolated
occlusions in a conveyed continuous rod in the tobacco industry, in
particular a continuous filter rod, wherein the rod is irradiated
by a light source with the aid of the light-transmission method and
wherein the brightness caused by the light source in the irradiated
continuous rod is at least partially detected by a sensor. The
detected brightness is used for determining the presence of
isolated occlusions in the continuous rod.
[0018] The method according to the invention is based on the
principle of detecting and identifying on a filter-rod maker and/or
system the number and/or locations of inserted non-homogeneities
and, if necessary, also the longitudinal axial spacing between the
occlusions in a continuous filter rod by using light, and in
particular laser light. The light conductivity is reduced owing to
the non-homogeneities in the continuous filter rod, thus resulting
in a brightness profile that differs from the profile of a filter
rod section without non-homogeneity. The change in the brightness
profile due to the occlusion is significant enough to allow
detecting the non-homogeneity in the continuous filter rod. The
difference in the light conductivity between the continuous filter
rod material and the inserted non-homogeneity results in a signal
that can be evaluated.
[0019] It is advantageously proposed that the brightness is imaged
at least in part on the sensor with the aid of an imaging
device.
[0020] The continuous rod is furthermore irradiated by means of a
laser light source which preferably emits light in the visible red
light range.
[0021] According to one embodiment, it is advantageous if the
continuous rod is irradiated with the aid of at least two light
sources.
[0022] According to another embodiment of the method, the position
and/or the number of occlusions are identified with the aid of the
detected areas of brightness.
[0023] It is furthermore advantageous to remove the continuous rod
and/or the continuous filter rod or a section of the continuous rod
and/or the continuous filter rod if the detected brightness values
differ from predetermined control values.
[0024] An evaluation device can advantageously be used to detect
the presence of occlusions in the continuous rod and/or the
continuous filter rod.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] These and other features and advantages of the invention
will be further understood from the following detailed description
of the exemplary embodiments with reference to the accompanying
drawings.
[0026] FIG. 1 is a schematic representation showing a filter-rod
maker, provided with a detection device according to the
invention.
[0027] FIG. 2 is a longitudinal section through an embodiment of a
detection device according to the invention.
[0028] FIG. 3 is a cross section through a second embodiment of a
detection device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] In the drawings, the same and/or similar elements or parts
are provided with the same reference numbers and will not be
introduced again.
[0030] FIG. 1 shows a schematic view from the side of an apparatus
for producing a continuous filter rod, in particular for producing
cigarette filters and similar types of smoking articles. This
apparatus includes two main structural components: a filter-tow
processing machine 1 for producing an endless band of filter
material and/or filter-tow material; and a processing machine 2 for
producing wrapped individual filter rods.
[0031] The filter-tow processing machine 1, for example a machine
of the Type AF2, AF3 or AF4 by the Assignee of the present
application, which is known in the tobacco industry, is provided
with a roller pair 3 for continuously pulling an endless band of
filter material 4 from a bale 6. After being removed from the bale
6 and on its way to the roller pair 3, during which it is guided
across a deflection roller 5, the filter-tow band 4 passes by two
air nozzles 7 and 8. These air nozzles serve to spread out and
loosen up the weave of the filter-tow band 4. The roller pair 3 is
followed by two additional roller pairs 9 and 11, between which an
application device 12 is arranged for applying plasticizer to the
spread-out filter-tow band 4 that is guided between the roller
pairs 9 and 11.
[0032] The roller pairs 3 and 9 jointly form a stretching device.
The speed of the roller pair 3 is lower than the speed of the
roller pair 9 and can be changed by means of a drive unit 14, for
which the transmission ratio can be changed with an adjustment
motor 16. The speed ratio between the roller pairs 3 and 9
predetermines the degree of stretching of the filter material band
4. For the exemplary embodiment shown herein, the rollers of the
roller pair 3, which function as braking rollers, are driven.
However, they can also be operated in the form of drag rollers
which function as braking rollers due to the frictional
conditions.
[0033] The roller pairs 3, 9 and 11 can be driven by means of a
main drive motor 13 and via the belt drives 13a to 13c. One or
several separate, individually controllable drives can also be
provided for the roller pairs in place of a main drive motor
13.
[0034] The processed filter material band 4, which has been sprayed
with plasticizer, forms a continuous filler material rod 44 which
travels via the roller pair 11 from the filter-tow processing
machine 1 to an intake funnel 17 of the processing machine 2, for
example a machine of the Type KDF 2, KDF 3, or KDF 4 by the
Assignee of the present application, which is known in the tobacco
industry.
[0035] The continuous filler material rod 44 is compacted in the
processing machine 2 and is placed onto a wrapping tape 21, pulled
from a bobbin 18, and coated with glue by means of a glue
applicator 19. The wrapping material tape 21 and the compacted
filler material rod 44 are moved to a format belt 22 which moves
both components through a format machine 23 where the wrapping tape
21 is wrapped around the continuous rod 44 of filter material,
thereby creating an endless filter rod 24. This endless rod passes
through a smoothing iron and/or a cooling section in which the glue
on the overlapping seam hardens.
[0036] A smoothing iron is provided at this location if the glue
applied to the wrapping tape is wet glue, wherein the seam is dried
in the smoothing iron. A cooling section is provided if the
wrapping tape 21 is provided with hot-melt glue, which is hardened
by cooling it in the cooling section 26. Following this, the
continuous filter rod 24 is transported through a detection device
100 according to the invention, so as to locate non-homogeneities
purposely introduced into the continuous filter rod 24 with respect
to their location and spacing.
[0037] Individual filter rods 28 are then cut continuously from the
filter rod 24 by a knife apparatus 27 and are subsequently
transferred by an accelerating device 29 to a delivery drum 31, in
which they are conveyed while positioned transverse to the
conveying direction. From the delivery drum 31, the filter rods are
moved to a delivery belt 32 for conveying them to a different
processing machine or to an intermediate storage location.
[0038] FIG. 2 shows a longitudinal section through an embodiment of
a detection device 100 according to the invention, comprising a
laser light source 122 and a sensor 114, arranged opposite the
laser light source 122. A continuous filter rod 24, produced with
purposely inserted occlusions or non-homogeneities 130, is conveyed
between the laser light source 122 and the sensor 114.
[0039] The continuous filter rod 24 of cellulose acetate contains
regularly spaced apart occlusions or non-homogeneities 130 on the
inside. The occlusions or non-homogeneities 130 are disposed
preferably near the center axis of the continuous filter rod 24.
The occlusions or non-homogeneities 130 are purposely inserted into
continuous filter rod 24, for example with the aid of a machine as
disclosed in European patent document EP-A-1 012 961. The
occlusions or non-homogeneities 130 are, for example, small
capsules, flakes, grains, or additive grains, or predetermined
planned holes, in particular inserted with equidistant spacing.
[0040] The continuous filter rod 24 is irradiated on the
transmitting side with the aid of a light-transmission method,
using the laser light source 122. With the aid of the laser light
source 122, a line-shaped ray is directed point-shaped or
fan-shaped onto the continuous filter rod 24, so that the light ray
enters point-shaped and perpendicular into the continuous filter
rod 24. From this point of entry, the light propagates cone-shaped
inside the continuous filter rod 24 as a result of scattering, as
shown in FIG. 2. The light entering the filter rod 24 at a point or
apex of the cone is thus spread out due to the scattering so that a
propagation cone is formed that increases in diameter to the side
of filter rod 24 where the light exits the continuous filter rod in
the region between points A-B.
[0041] With the exemplary detection device 100, shown in FIG. 2,
the dimension of the planes and/or the spacing between the planes
S1, S2 is determined by the propagation cone for light fed into the
continuous filter rod 24 and/or the material of the continuous
filter rod, the propagation cone for the light source 122, as well
as the opening angle shown by lines 111, 112 for the receiving
optic on the opposite side of the continuous filter rod 24 from the
laser light source 122. Planes S1 and S2 include the point of
intersection of the propagation cone for the light fed into the
continuous filter rod 24 and the lines 111, 112 indicating the
opening angle of the receiving optic. The propagation cone for the
light in the continuous filter rod 24 and/or the material is
determined by the material properties of the continuous filter rod
24 and/or material and therefore cannot be influenced from outside
the filter rod.
[0042] A diaphragm 116 is provided on the receiver side of the
continuous filter rod 24 in front of the sensor 114, which may be a
photodiode in a preferred embodiment. Owing to geometric
conditions, light travels at a specific angle from the side where
the light exits the continuous filter rod 24, through the diaphragm
116, and onto a photo-sensitive layer in the sensor 114.
Transferred to the surface of the filter rod 24, this means that
light reaching zone I-II, shown in FIG. 2, travels to the
photo-sensitive layer of the sensor 114. That is, only a portion of
the light exiting filter rod 24 is evaluated by the receiving
optic.
[0043] The influence of the opening angle indicated by lines 111,
112 for the receiving optic on the exit side is furthermore
minimized by providing an imaging device 126 so that light can pass
only through a short section or zone I-II of the continuous filter
rod 24 surface and onto the photo-sensitive layer of sensor 114.
The imaging device 126 may be in the form of a lens 126, which
focuses light onto diaphragm 116. As a result, the spacing between
the two planes S1, S2 is reduced.
[0044] Once a continuous filter rod 24, provided with at least one
non-homogeneous area 130, enters the measuring zone of detection
device 100, the beam of light that is transmitted through the
continuous filter rod 24 creates a light-dark brightness profile. A
light-dark transition is intensified by the non-homogeneous area
once it reaches the plane S2. The intensity transition is completed
once it passes through the parallel plane S1.
[0045] The light emitted by the laser light sources, for example in
the red visible range (wavelength approximately 655 nm), passes
through the continuous filter rod 24 and impinges on the sensor
114. The electrical signal from the sensor is then fed to an
evaluation unit 120. The changes in the brightness profile and/or
the signal to be evaluated are detected by means of the evaluation
unit 120, thus making it possible to determine by means of the
evaluation unit 120 whether the beam path contains a
non-homogeneity 130. The brightness profile depends on the
differences in the light conductivity of the material in the
continuous filter rod 24 and/or the non-homogeneities 130.
[0046] The non-homogeneities 130 cause a reduction in the light
conductivity, so that the non-homogeneity 130 can be localized
and/or detected on the basis of the change in the brightness
profile. Using the transporting speed for the continuous filter rod
24, as well as the measured brightness profiles, it is also
possible to determine the spacing between the isolated
non-homogeneities and, if necessary, also the dimensions of the
non-homogeneities 130.
[0047] For a secure detection of the non-homogeneities 130 and/or
the capsules, the brightness profiles are compared to a
predetermined control value or a predetermined control brightness
profile. The existence or lack of a non-homogeneity 130 in the
continuous filter rod 24 is then determined based on the deviations
from these control values.
[0048] If, for example following the detection of one
non-homogeneity 130, no further non-homogeneity is detected in the
continuous filter rod 24 at a predetermined distance to the
location of the previously detected non-homogeneity 130, the
corresponding section of the continuous filter rod 24 is removed
from the further production process during a following production
step.
[0049] The propagation cone for the light from the laser light
source 122, used to irradiate the section A-B on the surface of the
continuous filter rod 24, depends on the size of the cone angle.
The opening angle indicated by lines 111, 112 for the receiving
optic is fixed by the dimensions for the diaphragm 116 and the
photo-sensitive layer of the sensor 114.
[0050] FIG. 3 shows a different exemplary embodiment of an
arrangement for detecting and/or localizing non-homogeneities in a
continuous filter rod 24. This embodiment utilizes two detection
devices 100, arranged transverse to the conveying direction for the
continuous filter rod 24, so that the continuous filter rod 24 is
irradiated in a single plane by two laser light sources 122.
[0051] As a result of a measuring and/or detecting operation along
two axes, these operations can be carried out independent of the
axial position of the non-homogeneities 130 in the continuous
filter rod 24. In the process, the brightness profiles detected by
the sensors 114 are transmitted further to the joint evaluation
unit 120. Since the laser light sources 122 and the sensors 114 are
arranged in a plane that is positioned perpendicular to the
conveying direction for the continuous filter rod, it is possible
to determine the precise position of the non-homogeneities in the
continuous filter rod 24 on the basis of irradiating the continuous
filter rod 24 along two axes.
[0052] The invention has been described in detail with respect to
preferred embodiments, and it will now be apparent from the
foregoing to those skilled in the art, that changes and
modifications may be made without departing from the invention in
its broader aspects, and the invention, therefore, as defined in
the appended claims, is intended to cover all such changes and
modifications that fall within the true spirit of the
invention.
* * * * *