U.S. patent application number 09/709889 was filed with the patent office on 2002-02-28 for method and apparatus for rotating rotationally symmetrical containers, such as bottles, while transporting them under backup pressure.
Invention is credited to Goller, Hans-Ulrich, Heuft, Bernhard.
Application Number | 20020023821 09/709889 |
Document ID | / |
Family ID | 8015851 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020023821 |
Kind Code |
A1 |
Heuft, Bernhard ; et
al. |
February 28, 2002 |
Method and apparatus for rotating rotationally symmetrical
containers, such as bottles, while transporting them under backup
pressure
Abstract
Rotationally symmetrical containers (10) are transported under
backup pressure on a conveying surface (12) limited laterally by
railings (14). For rotating the containers (10) at a predetermined
site along the conveying surface (12), one of two consecutive
containers (10) is arranged stable against one railing (14) and the
other stable against the other railing (14) in the direction of
conveyance after the site at which the containers are to
rotate.
Inventors: |
Heuft, Bernhard; (Burgbrohl,
DE) ; Goller, Hans-Ulrich; (Godesberg, DE) |
Correspondence
Address: |
GARDNER, CARTON & DOUGLAS
321 N. CLARK STREET
SUITE 3400
CHICAGO
IL
60610
US
|
Family ID: |
8015851 |
Appl. No.: |
09/709889 |
Filed: |
November 10, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09709889 |
Nov 10, 2000 |
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08875393 |
Jul 23, 1997 |
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6155408 |
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08875393 |
Jul 23, 1997 |
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PCT/EP96/05193 |
Nov 25, 1996 |
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Current U.S.
Class: |
198/411 |
Current CPC
Class: |
B65G 47/244
20130101 |
Class at
Publication: |
198/411 |
International
Class: |
B65G 047/244 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 1995 |
DE |
295 18 628.3 |
Claims
1. Method for rotating rotationally symmetrical containers (10) at
a predetermined site along a conveying surface (12) which is
limited laterally by railings (14) and on which the containers (10)
are transported under backup pressure, characterized in that one of
two consecutive containers (10) is arranged stable against one
railing (14) and the other stable against the other railing (14) in
the direction of conveyance after the site at which the containers
are to rotate.
2. Apparatus for carrying out a method according to claim 1,
characterized in that a stabilizing device for the stable
arrangement of one of at least two consecutive containers (10) at
one railing (14) and of the other container (10) at the other
railing (14) is provided at the exit of the apparatus.
3. Apparatus according to claim 2, characterized in that the
distance between the railings (14) is about 1.2 to 1.5 times the
diameter of the container in the area of the conveying surface (12)
preceding the stabilizing device.
4. Apparatus according to claims 2 or 3, characterized in that the
stabilizing device is formed by the distance of the two lateral
railings (14) between each other in the direction of conveyance
increases to about 1.5 times the diameter of the containers (10)
and then reduces at an angle of the lateral railings (14) to each
other of about 30 to 100.degree., preferably 50 to 80.degree., to
about somewhat more than the diameter of the containers (10).
5. Apparatus according to claim 4, characterized in that the two
lateral railings (14) run symmetrical to the midline of the
conveying surface in the area in which their distance between each
other reduces at angle of about 30 to 100.degree..
6. Apparatus according to claim 2 or 3, characterized in that the
stabilizing device is formed by a star wheel (30) which is arranged
adjacent to the conveying surface (12), is freely rotatable about a
vertical axis and lays every second container (10) against the
opposite railing (14).
7. Apparatus according to claims 2 or 3, characterized in that the
stabilizing device is formed by a worm (34) which is arranged
adjacent to the transporter (12), has an about vertical axis and
has threads of alternately different depth, their arrangement being
such that the threads with lesser depth lay each second container
(10) against the opposite railing (14).
8. Apparatus for inspection of the side wall or for monitoring the
labels of rotating containers (10) which are transported on a
transporter (12.) and comprising a radiation source (18) on one
side of the transporter (12) and an identification device (20) on
the other side of the transporter (12), characterized in that the
containers (10) are rotated by a device according to claims 2 to 7
within the visual field of the detection device (20).
9. Apparatus for transporting rotationally symmetrical containers
(10) on a conveying surface (12) under backup pressure, a railing
(14) being arranged on each side of the conveying surface (12),
characterized by at least one device according to one of claims 2
to 7.
Description
[0001] The invention relates to a method and apparatus for rotating
rotationally symmetrical containers, such as bottles, while
transporting them on a conveying surface. The containers are
transported under backup pressure and are guided during the
transportation, for which the conveying surface has a guide device
or a railing on each side.
[0002] In particular empty glass or plastic bottles are rotated
about their axis for inspecting their side walls. A side wall
inspection device is known from EP-A-0 415 154 with which the
lateral guide devices consist of belts arranged on both sides of
the conveying surface and driven at different speeds so that the
empty bottles held between them are rotated about their
longitudinal axis. That apparatus requires that the empty bottles
have previously been separated or at least guided to the conveying
surface free of backup pressure. Therefore, if the empty bottles
are not arranged free of pressure, they must be separated.
[0003] The invention is based on the problem of enabling the
rotation of containers conveyed under backup pressure about their
longitudinal axis in a simple manner.
[0004] This problem is solved according to the method of the
invention in that one of two consecutive containers is arranged
offset stable to one side and the other stable to the other side
seen in the direction of conveyance after the site at which the
containers are to rotate.
[0005] The problem is solved within the scope of the apparatus of
the invention in that a device is provided for the stable
arrangement of one of at least two consecutive containers against
the railing and the other container against the other railing in
the direction of conveyance after the site at which the containers
are to rotate.
[0006] Apparatuses are known from DE-C-843 973 and DE-C-922 519 for
transporting empty bottles under backup pressure with which empty
bottles are alternately offset to the left and to the right
railing. However, with those apparatuses, disturbances that lead to
a change in the position of a container from one railing to the
other railing propagate from the exit end of the conveying device
counter to the direction of transportation. Such a change in
position then also leads to a reversal of the direction of rotation
of the individual empty bottles so that a defined rotation of the
empty bottles is not achievable.
[0007] According to the basic concept of the present invention, a
stable arrangement of at least two containers at the left or,
resp., right railing prevents such a disturbance and a change in
the position of the individual containers caused by that from
taking place after those containers.
[0008] All subsequent containers lie stable against one of the two
railings and roll along the railing and against each other, the
containers rolling alternately along the left and right railing
with alternate direction of rotation.
[0009] An apparatus for transporting rotationally symmetrical
containers is known from U.S. Pat. No. 2,725,138, the containers
backing up at the end of the conveying surface and rolling along
the side rails. At the end of the conveying surface, the containers
are arranged at defined distances on a further transporting device
by means of a star wheel. Upon being taken over by the star wheel,
each container is pushed laterally against the same railing. Hence,
the containers which were previously positioned at the other rail
change their position. That change of position causes all
subsequent containers likewise to change their position and
therewith also their direction of rotation.
[0010] The conveying surface can be moving or fixed. Moving
conveying surfaces are conveyer belts, chain link conveyers, air
cushions, rollers and the like. Fixed conveying surfaces can be
simple metal slideways on which the containers are pushed by means
of backup pressure, the backup pressure can be produced by a star
wheel or a seriesed chain link conveyer.
[0011] In this context, the term "transporter" encompasses all
these kinds of conveying surfaces.
[0012] In a first embodiment of the device for stabilizing the
position of at least two consecutive containers, the distance
between the two railings in the direction of conveyance is to begin
with gradually broadened to about 1.5 times the diameter of the
containers and then narrowed down at an angle of the two railings
to each other of about 30 to 100.degree., preferably 50 to
80.degree., to somewhat more than the diameter of the containers.
The path of the railings in this area preferably mirrors or is
symmetrical to the midline of the transporter.
[0013] The distance between the two railings has an effect on the
pressure conditions in the stream of the containers. The following
relationships are applicable:
.alpha.=arc sin (V/D)
V=D-d 1 F 1 n = ( 2 n - 1 ) F R sin cos = ( 2 n - 1 ) F R tan F 2 n
= n F R cos
[0014] V=lateral displacement of consecutive containers;
[0015] D=distance between the lateral rails (width of the
transporter);
[0016] d=diameter of the containers;
[0017] .alpha.=angle between the connecting line of two consecutive
containers and the direction of transportation;
[0018] F.sub.1n=the force of the nth container acting on the
railing;
[0019] F.sub.2n=the force component acting on the subsequent
container
[0020] F.sub.R=friction force between container and railing.
[0021] The apparatus works stable in a broad range of the backup
pressure. However, in practice, extreme situations which can lead
to disturbances in the rotation behavior of the container result
due to most varied influences. Those influences can be allayed by
additional measures so that a disturbance of the operation is
largely prevented. Very strong pressure at the upstream end of the
apparatus can be reduced by a mechanical resistance in the course
of the transporter before the apparatus. For example, there can be
arranged on the transporter a thin metal sheet over which the
containers slide and thereby undergo an additional friction.
Baffles which reduce the pressure peaks can also be built up by
means of the side railings. The backup pressure is also reduced by
the apparatus of the invention itself so that the backup pressure
for a subsequent apparatus is reduced by a preceding apparatus. If,
vice versa, too low a backup pressure exists, the container can be
imparted a force acting in the direction of transportation by a
laterally arranged belt running along with it.
[0022] By narrowing the distance between the railings at a
relatively large angle, it is achieved that in the case that a
container at the section of the transporter again narrowed down
changes its position from one railing to the other, this does not
have any influence on the position of the subsequent container
still within the narrowing area. That is to say, the pressure point
between the two containers shifts so slightly due to the narrow
free movement area of the preceding container that the subsequent
container is not forced to change its position to the other
railing. The chaotic behavior of the containers is therewith
interrupted and a clear and stable arrangement of the containers is
attained.
[0023] In a second embodiment, the device for stabilizing the
position of at least two consecutive containers is a star wheel
that is arranged rotatable about a vertical axis adjacent to the
transporter and has cutouts on its perimeter of alternately
different depth that are distributed to correspond to about the
diameter of the containers such that the teeth push every second
container against the opposite railing while the intermediate
containers rest against the adjacent railing due to the cutouts.
Two such star wheels can also be arranged meshing on the left and
right adjacent to the transporter, the containers then passing
through between the two star wheels.
[0024] A stable arrangement of the containers is also possible
alternately at the one and the other railing by means of a worm
arranged adjacent to the transporter.
[0025] The distance between the two railings is normally only
slightly, e.g. 1 to 10 mm, greater than the diameter of the
containers. For transportation purposes, such a distance between
the railings was hitherto viewed to be sufficient, and the
containers jumping back and forth from one railing to the other and
the associated change of rotational direction during transport was
accepted as being unavoidable. This chaotic behavior can be
prevented by the invention. In the area in which each container is
to have a defined position and rotational direction proceeding from
the stabilization device counter to the direction of conveyance,
the distance between the railings is there preferably greater than
the distance quoted above and is about 1.2 to 1.6 times, preferably
1.4 to 1.5 times, the diameter of the containers.
[0026] Within this area with increased distance between the
railings on the two sides, the containers alternately rotate in
opposite directions about their vertical axis and at the same time
each roll alternately along the left and right railings. The
stability of the position of the containers is also improved by the
friction of the containers against each other being greater than
the friction between them and the undersurface, i.e., the
transporter, and the railings.
[0027] The device according to the invention can be used generally
when the containers must rotate when they are handled and
inspected.
[0028] The apparatus according to the invention can be used for all
types of container inspections that require an unrolling of the
surface of or a rotation of containers, e.g. to monitor the
placement of labels, the mouth or thread, to check the rotational
symmetry of the containers, to monitor the side wall, etc., further
devices then not being required to rotate the containers. The side
walls are there expediently inspected in an area in which the
containers (viewed from the side) overlap as little as possible but
have already assumed a stable position against one of the two
railings. This is generally the area in which the distance between
the two railings is about about 1.2 times the bottle diameter.
[0029] The apparatus according to the invention can, however, also
be used to avoid container noise and wear in the congestion area of
transporting devices. The noise and the wear are substantially
reduced by the containers rolling against each other and the
railings in a controlled manner. When the apparatus according to
the invention is used for this purpose over longer distances, it
can be expedient to distribute several of the apparatuses over the
distance, e.g. at railings that are far apart (about 1.5 times the
bottle diameter) which can be provided with a soft surface for
additional reduction of noise and wear.
[0030] Furthermore, as a result of the controlled surface unrolling
of rotationally symmetrical bodies, the apparatus according to the
invention can also use be used for printing, coating or applying
films, labels or caps to containers. The purposive removal of
films, labels or caps is similarly possible with the apparatus
according to the invention. It is further of advantage with the
apparatus according to the invention that most of the bottle
filling machines used at present require backup pressure at their
feed area. Therefore, due to the apparatus according to the
invention, not only do the bottles not have to be separated before
the side wall inspection device, rather is the device for producing
the backup pressure before the filling machine also not needed.
[0031] Embodiment examples of the invention are explained in the
following with reference to the drawings in which:
[0032] FIG. 1 is a top view of the apparatus for rotating empty
bottles in conjunction with a device for side wall inspection;
[0033] FIG. 2 is a vertical section of the apparatus of FIG. 1
viewed in the direction of the transporter;
[0034] FIG. 3 is a top view of another embodiment example of the
apparatus for rotating containers;
[0035] FIG. 4 a further embodiment example of the apparatus for
rotating containers and
[0036] FIG. 5 the course of the railing for bottles with a diameter
of 55-87 mm.
[0037] In accordance with FIG. 1, empty bottles 10 are transported
on a transporter 12, e.g. a conveyer belt or a link conveyer, in
the direction of the arrow. On each side of the transporter 12 is a
fixed railing 14 to hold the empty bottles 10 on the transporter 12
even when there is backup pressure. As indicated by the individual
arrows 16, the bottles 10 rotate alternately in opposite direction
due to their mutual contact and their contact with the railings 14,
the bottles 10 alternately resting against the left and right
railings 14.
[0038] An inspection station to inspect the side walls of the
bottles 10 is provided that has a radiation source 18 arranged
adjacent to the transporter 12 and a detection device 20, e.g. a
CCD camera, arranged on the opposite side. Both are constructed and
operate in the usual manner and are, therefore, not described in
more detail. Within the normal transportation area, the railing 14
is located at about a half the height of the empty bottles 10. In
the area of the inspection station, the railing 14 is arranged
lower so that the empty bottles 10 are held by the railing 14 at
their bottom edges. The empty bottles are guided at the top at
their necks by an additional railing 15 (FIG. 2). One of the two
railings 14, 15, preferably the lower railing 14, can be provided
with a higher friction coating. The empty bottles 10 then slide
along the upper railing 15. If the apparatus according to the
invention is used in conjunction with an apparatus for inspecting
the base of the containers as according to the simultaneously filed
PCT application, "Method and apparatus for transporting containers
past an apparatus for inspecting the base of the containers" (our
reference: 30562/Boden-inspektion), this additional railing 15 can
be an extension of the neck guide according to FIG. 2 of this
simultaneously filed utility model application. The containers
found to be faulty in the base inspection or the side wall
inspection can be separated out by an apparatus according to the
likewise simultaneously filed PCT application "Apparatus for
separating individual or a plurality of rotationally symmetrical
containers from a stream of rotationally symmetrical containers
conveyed under backup pressure and cylinder having a piston
extensible in a controlled manner" (our reference:
30561/Loffel).
[0039] When empty bottles are transported under backup pressure on
a transporter at substantially unchanging distance between the
lateral railings, the position of the bottles is unstable, i.e. the
bottles now and then jump chaotically from one railing to the
opposite railing or change their rotational direction. It is
achieved by the apparatus according to the invention that the
individual bottles 10 rest stably against one of the two railings
14 within a certain area and retain their rotational direction. The
distance between the two railings 14 at the exit of the apparatus
is there somewhat more than the diameter of the bottles 10, as is
customary for transporting under backup pressure. This distance is
then increased to 1.2 to 1.3 times the diameter of the bottles 10
within a length corresponding to about the diameter of the bottles
10. This increased distance is then maintained within a first area
24 whose length depends on the circumstances involved. It is
sufficient for a side wall inspection when the length of this first
area 24 corresponds to about 4 times the bottle diameter. In the
following second area 26, the distance between the railings 14
gradually increases, i.e. within a length corresponding to about 2
to 3 times the bottle diameter, to 1.5 times the bottle diameter
and then reduces within a substantially shorter third area 28,
whose length corresponds to about 1.5 times the bottle diameter, to
the initial length of somewhat more than the bottle diameter.
[0040] Disturbances in the position of the bottles 10 generally
arise at the exit end of a transporter, e.g. by removing a bottle,
and then propagate counter to the direction of conveyance. If the
last bottle changes its position from left to right, the pressure
point changes with respect to the last bottle but one so that it
jumps from right to left and this change in position then
propagates counter to the direction of conveyance over the entire
length of the transporter. Since the bottles at the exit end of the
third area 28 are very markedly offset from each other, and in
particular the last bottle 11 within the third area 28 is offset
relatively far to the side of the following bottle 10 that is in
the again narrow area 29 subsequent thereto, the pressure point
between these two bottles does not change so markedly when the
bottle in the narrow area 29 changes its position that the last
bottle in the third area 28 changes its position toward the other
railing 14.
[0041] In FIG. 5, the course of the railings 14 is shown for a
transporter 12 with which bottles are transported whose diameter D
ranges from 55 to 87 mm. L.sub.2 is the length of the first area
24, L.sub.3 that of the second area 26 and L.sub.4 that of the
third area 28. The lateral distance between the railings at the
inlet and outlet (area 29) is a few millimeters greater than the
bottle diameter D.
[0042] FIG. 2 shows a section of the device for side wall
inspection viewed counter to the direction of transportation. The
side wall inspection is arranged in the first area 24 because the
distance between the railings 14 is there only about 1.2 to 1.3
times the bottle diameter so that the bottles 10 overlap only
slightly viewed from the side. The field of vision of the camera is
selected such that several bottles 10 are comprised simultaneously
and a complete unrolling of the side wall of each bottle within the
field of vision of the camera results due to the rotation of each
bottle. Each point on the surface of the bottle can therewith be
examined at least once.
[0043] FIG. 3 shows an embodiment example with which the device for
stabilizing the position and rotational direction of the containers
10 is formed by a star wheel 30 arranged adjacent to the
transporter 12 and rotatable about a vertical axis. The star wheel
30 is divided into sections equal to about the diameter of the
containers 10 and has cutouts 32 of alternately different depth.
Due to this design, the star wheel 30 presses each second container
10 against the opposite railing so that the intermediate containers
10 necessarily rest against the railing 14 close to the rotary axis
of the star wheel 30. Due to this obligatory positioning of the
containers 10 by the star wheel 30, a disturbance cannot propagate
counter to the direction of transportation beyond the star wheel
30. Each container 10 can also be held between two star wheels
30.
[0044] FIG. 4 shows a similar embodiment example, the device for
stabilizing the position and rotational direction of the containers
10 is a worm 34 arranged adjacent to the transporter 12 and having
an approximately horizontal rotary axis. The worm has threads with
alternately different depth so that each second container 10 is
pushed against the opposite railing. In this case, too, it is in
turn possible to arrange a worm 34 at both sides of the transporter
12.
* * * * *