U.S. patent application number 16/495695 was filed with the patent office on 2020-03-05 for method and device for the production of filled containers from thermally conditioned preforms.
The applicant listed for this patent is KHS Corpoplast GmbH. Invention is credited to Benjamin JAISER, Michael LINKE, Deniz ULUTURK.
Application Number | 20200070397 16/495695 |
Document ID | / |
Family ID | 64453512 |
Filed Date | 2020-03-05 |
United States Patent
Application |
20200070397 |
Kind Code |
A1 |
JAISER; Benjamin ; et
al. |
March 5, 2020 |
METHOD AND DEVICE FOR THE PRODUCTION OF FILLED CONTAINERS FROM
THERMALLY CONDITIONED PREFORMS
Abstract
A method and device for producing containers filled with liquid
content from preforms made of thermoplastic material. The liquid
content is fed as a pressure medium into thermally conditioned
preforms during a forming and filling phase in a mold of one of a
plurality of forming stations arranged circumferentially spaced
apart on a common, continuously rotationally driven working wheel.
A compensating device compensates for thermal consequences of
centrifugal force acting on the liquid content fed into the preform
during the forming and filling phase. The compensating device
imparts a temperature profile to the preform in a circumferential
direction, which is not point-symmetrical in relation to a
longitudinal axis of the preform to produce a thermally
differentiated partial circumferential region. The preform is
inserted into the mold such that the thermally differentiated
partial circumferential region faces in a radial direction of the
working wheel.
Inventors: |
JAISER; Benjamin; (Hamburg,
DE) ; LINKE; Michael; (Hamburg, DE) ; ULUTURK;
Deniz; (Hamburg, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KHS Corpoplast GmbH |
Hamburg |
|
DE |
|
|
Family ID: |
64453512 |
Appl. No.: |
16/495695 |
Filed: |
November 22, 2018 |
PCT Filed: |
November 22, 2018 |
PCT NO: |
PCT/EP2018/082169 |
371 Date: |
September 19, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 49/36 20130101;
B29C 2049/4664 20130101; B29C 49/6436 20130101; B29C 49/06
20130101; B29C 2949/78899 20130101; B29C 49/78 20130101; B29C
49/786 20130101; B29C 49/12 20130101; B29L 2031/7158 20130101; B29C
2949/78663 20130101; B29C 49/68 20130101; B29C 49/08 20130101; B29C
49/64 20130101; B29C 49/6409 20130101; B29C 49/46 20130101 |
International
Class: |
B29C 49/64 20060101
B29C049/64; B29C 49/12 20060101 B29C049/12; B29C 49/36 20060101
B29C049/36; B29C 49/46 20060101 B29C049/46; B29C 49/78 20060101
B29C049/78 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2017 |
DE |
10 2017 011 087.5 |
Claims
1-13. (canceled)
14. A method for producing a container filled with at least one
liquid content from a preform made of a thermoplastic material,
said method comprising: thermally conditioning the preform along a
heating zone in a heating device; and subsequently, during a
forming and filling phase in a mold of a forming station, feeding
the at least one liquid content into the preform as a pressure
medium and thereby simultaneously forming and filling the container
with the at least one liquid content; wherein the forming station
is one of a plurality of forming stations arranged
circumferentially spaced apart on a common, continuously
rotationally driven working wheel at a radial distance from an axis
of rotation of the working wheel, wherein a compensating device is
used to compensate for thermal consequences of centrifugal force
acting on the at least one liquid content fed into the preform
during the forming and filling phase, wherein the compensating
device is a temperature control device, which imparts to the
preform a temperature profile in a circumferential direction which
is not point-symmetrical in relation to a longitudinal axis of the
preform and thereby produces a thermally differentiated partial
circumferential region in the preform, and wherein the preform is
inserted into the mold in such an alignment that the thermally
differentiated partial circumferential region is facing in a radial
direction of the working wheel.
15. The method according to claim 14, wherein, while the preform is
being formed into the container, the preform is guided and
stretched in a direction of its longitudinal axis at least for a
time by a stretching rod.
16. The method according to claim 14, wherein the thermally
differentiated partial circumferential region is heated more
strongly than remaining circumferential regions of the preform.
17. The method according to claim 14, wherein the temperature
profile imparted to the preform in the circumferential direction is
regulated or controlled as a function of a selected circumferential
speed of the working wheel.
18. The method according to claim 14, wherein the compensating
device is arranged in the heating zone of the heating device.
19. The method according to claim 14, wherein the thermally
differentiated partial circumferential region faces radially
outward after insertion of the preform into the mold of the forming
station.
20. The method according to claim 14, wherein the container is
rotationally symmetrical about its longitudinal axis, is formed
with n-fold symmetrical rotation, and wherein n is greater than
4.
21. The method according to claim 20, wherein n is greater than 8,
and wherein the container is substantially circularly
symmetrical.
22. The method according to claim 14, wherein the thermally
differentiated partial circumferential region has a partial
circumferential angle .PHI. of less than 180.degree..
23. The method according to claim 22, wherein the partial
circumferential angle .PHI. is less than 90.degree..
24. A device for producing containers filled with at least one
liquid content from preforms made of a thermoplastic material, said
device comprising: a plurality of forming stations each having a
forming and filling head and a mold, wherein each forming station
is configured to feed the at least one liquid content into one of
the preforms as a pressure medium and thereby simultaneously form
the one of the preforms into a container and fill the container
with the at least one liquid content during a forming and filling
phase in the mold; and a heating device for thermally conditioning
the preforms along a heating zone; wherein formation of the
container takes place against an inner wall of the mold with the
mold being closed, wherein the plurality of forming stations are
arranged circumferentially spaced apart on a common, continuously
rotationally driven working wheel at a radial distance from an axis
of rotation of the working wheel, wherein the device further
comprises a compensating device to compensate for thermal
consequences of centrifugal force acting on the at least one liquid
content fed into the preforms during the forming and filling phase,
wherein the compensating device is a temperature control device,
which is Imparts a temperature profile in the preforms, wherein the
compensating device further has a preform alignment device for
aligned insertion of the temperature-profiled preforms into
respective molds of the plurality of forming stations, wherein the
temperature control device is configured to impart the temperature
profile in the preforms in a circumferential direction, which is
not point-symmetrical in relation to a longitudinal axis of the
preforms and thereby produce a thermally differentiated partial
circumferential region in the preforms, and wherein the preform
alignment device is configured to insert the preforms into the
respective molds in such an alignment that the thermally
differentiated partial circumferential region is facing in a radial
direction of the working wheel.
25. The device according to claim 24, wherein the forming station
has a stretching rod configured to stretch the preform in a
direction of its longitudinal axis at least for a time during the
forming and filling phase.
26. The device according to claim 24, wherein the temperature
control device is arranged in the heating zone of the heating
device.
27. The device according to claim 24, wherein the temperature
control device is configured such that the thermally differentiated
partial circumferential region is heated more strongly than
remaining circumferential regions of the preforms.
28. The device according to claim 24, wherein the preform alignment
device is configured such that the thermally differentiated partial
circumferential region is facing radially outward after insertion
of the preform into the mold of a forming station.
29. The device according to claim 24, wherein the inner wall of the
mold is configured to produce the container such that the container
is rotationally symmetrical about its longitudinal axis, and has
n-fold symmetrical rotation, wherein n is greater than 4.
30. The device according to claim 29, wherein n is greater than 8,
and wherein the inner wall of the mold is configured to produce a
container having a substantially circular symmetry.
31. The device according to claim 24, wherein the temperature
control device is configured to control or regulate the temperature
profile of the preforms dependent on a circumferential speed of the
working wheel.
32. The device according to claim 24, wherein the thermally
differentiated partial circumferential region has a partial
circumferential angle .PHI. of less than 180.degree..
33. The device according to claim 32, wherein the partial
circumferential angle .PHI. is less than 90.degree..
Description
[0001] The invention relates to a method for producing containers
filled with a liquid content from thermally conditioned preforms
made from a thermoplastic material according to the preamble of
claim 1 and a device for producing containers filled with a liquid
content from temperature-conditioned preforms made of a
thermoplastic material according to the preamble of claim 7.
[0002] The production of containers by means of blow molding from
preforms made of a thermoplastic material, for example from
preforms made of PET (polyethylene terephthalate), is known,
wherein the preforms are supplied to different processing stations
within a blow molding machine. Typically, a blow molding machine
has a heating device for temperature control and/or thermal
conditioning of the preforms as well as a blowing device with at
least one blowing station, in which area the previously
temperature-conditioned preform is expanded into a container. The
expansion takes place with the help of a compressed gas
(pressurized air) as a pressure medium, which is introduced into
the preform to be expanded with a forming pressure. The
process-engineering sequence with such an expansion of the preform
is explained in DE 43 40 291 A1. The basic structure of a blowing
station is described in DE 42 12 583 A1. Possibilities of thermal
conditioning of the preforms are explained in DE 23 52 926 A1.
Thermal conditioning here is understood to mean that the preform is
heated to a temperature suitable for blow molding and optionally a
temperature profile is imparted to the preform in the longitudinal
direction and/or in the circumferential direction. The blow molding
of containers made from preforms with the additional use of a
stretching rod is likewise known.
[0003] According to a typical further processing method, the
containers produced by means of blow molding are fed to a
downstream filling device and filled with the intended product or
content here. Thus, a separate blow molding machine and a separate
filling machine are used. In doing so, it is also known to combine
the separate blow molding machine and the separate filling machine
into a machine block, i.e. into a combined blow-molding filling
device, wherein still the blow molding and the filling take place
on separate machine components and one after the other.
[0004] Furthermore, it has already been proposed to produce
containers, particularly also in the form of bottles, from
thermally conditioned preforms and, in doing so, to simultaneously
fill with a liquid content, which is supplied as a hydraulic
pressure medium to expand the preform and/or to form the container
with a forming and filling pressure such that the respective
preform is formed into the container at the same time as the
filling. Such methods in which simultaneous forming and filling of
the respective container takes place can also be characterized as a
hydraulic forming process or as hydraulic container forming. It is
also known here to support this forming by the use of a stretching
rod. In this case as well, the preform is initially
temperature-conditioned before the forming and filling process,
i.e. is heated to a temperature suitable for the hydraulic forming
and optionally imparted with a temperature profile.
[0005] When forming the container from the preforms by means of the
content to be filled itself, i.e. with the use of the content as a
hydraulic pressure medium, only one machine is required for the
forming and filling of the container, said machine, however, having
increased complexity for this. An example of such a machine is
shown in U.S. Pat. No. 7,914,726 B2. DE 10 2010 007 541 A1 shows a
further example.
[0006] The simultaneous forming and filling of a container from a
preform takes place in a forming station, which has, inter alia, a
multipart mold. The multipart structure of the mold is required in
order to insert a preform into the mold and to remove the
completely formed and filled container from the mold after
completion of the forming and filling process. The multipart mold
in this case is arranged in the forming station and designed such
that the mold can have a closed state and an open state. In the
closed state, the multipart mold encloses an inner cavity and, in
the closed state, the multipart mold forms an inner wall of the
mold, against which the preform expands in the closed state by
supplying the liquid content into the preform at a pressure and
into the container bubble resulting from the preform until the
final container form is obtained, wherein this forming process is
preferably supported, at least for a time, by a stretching rod, in
which said stretching rod is inserted into the preform against the
closed base of the preform. The stretching rod has the task of
stretching the preform in the axial direction and guiding the
expansion thereof, at least for a time. Furthermore, it is
customary for the forming stations to be cyclically or periodically
fed a preform, and completely formed containers are removed from
the mold cyclically or periodically. Also known, for example, are
cyclically working machines with multiple forming stations or also
machines functioning according to the rotation principle with
continuously circulating working wheels on which multiple forming
stations are arranged circumferentially spaced apart and at a
radial distance from an axis of rotation of the working wheel. The
invention relates to these machines of the rotational type.
[0007] Compared to the production process and compared to the
devices with the blow molding of preforms into containers while
using a pressurized gas, there are particularities and problems
which have not yet been solved in a fully satisfactory manner with
the forming of preforms into containers with simultaneous filling
by means of the use of a filling material as a liquid pressure
medium. The present invention relates to such a particularity and
such a problem which occurs with machines functioning according to
the rotation principle.
[0008] Centrifugal forces due to the introduction of a gas as a
pressure medium during container forming have not played any
significant role until now; thus, the centrifugal force is
significantly more strongly pronounced during the production of the
container due to the introduction of a pressurized liquid, because
the introduced liquid has a much greater mass than a pressurized
gas and is thus pressed outward with more force. On one hand, this
has the consequence that the wall area of the preform, which is
lying radially outward, and/or the developing container bubble is
cooled more strongly by the filled content. On the other hand, it
has been determined that the preform will make contact radially
outward on the inner wall of the mold earlier.
[0009] However, this effect is partially reduced by means of the
use of a stretching rod. Nevertheless, the centrifugal force leads
to the aforementioned effect that a certain area of the developing
container bubble, namely the area lying radially outward, makes
contact with the inner wall of the mold earlier than an area lying
radially inward and thereby, e.g., cools off earlier when the inner
wall of the mold is colder than the preform and/or the container
bubble, which is regularly the case, provided there are not
hot-fill-forming and filling processes present in which the mold,
e.g., is maintained at an increased temperature, which may be close
to the forming temperature of the preform. The disadvantage here is
that the temperature in the preform and/or in the developing
container bubble has significant influence on the material
distribution in the finished container. In this respect, the
aforementioned cooling effects lead to a deviation in the material
distribution in the finished container from the targeted material
distribution.
[0010] There have been no solutions to this problem in the prior
art up until now and the prior art also has not previously
described this problem, because this problem is specifically for
the simultaneously implemented forming and filling process of
containers from preforms.
[0011] Thus, the object of the present invention is to provide a
method and a device for the production of filled containers from
temperature-conditioned preforms, which solve the previously
mentioned problem with high forming and filling rates in
addition.
[0012] This object is achieved by means of a method with the
features of claim 1. Accordingly, it is provided that the thermal
consequences of the centrifugal force are compensated for by a
compensating device. Said compensating device should be designed as
a temperature control device in order to impart a compensating
temperature profile to the preform, wherein said temperature
profile is designed in its symmetry and in its size to compensate
for the previously described thermal consequences of the rotational
movement of the containers and of the forming fluid filled therein.
These thermal consequences are primarily the previously explained
early contact of the wall area, lying outward radially, of the
preform with the inner wall of the mold. According to the
invention, the compensating device in the form of the temperature
control device is designed to impart a temperature profile to the
preform in the circumferential direction thereof, which is not
point-symmetrical in relation to the longitudinal axis of the
preform, wherein this symmetrical observation naturally relates to
a section perpendicular to said longitudinal axis of the preform;
thus, the temperature distribution is considered in the
circumferential direction in this sectional plane and thus
generates a thermally differentiated partial circumferential region
in the preform. The preform is then inserted into the mold at such
an alignment that the thermally differentiated partial
circumferential region is facing in the radial direction of the
rotating circumferential working wheel. To this end, a suitable
temperature profile to be imparted can be, e.g., empirically
determined by means of a few tests, e.g. in which the material
distribution, e.g. measured by means of wall thicknesses, is
determined in the circumferential direction of the container with
container production without compensation and with the specified
compensating temperature profiles. It is also possible to adjust
and/or readjust the compensating temperature profile by means of a
control and/or regulation and by measuring wall thicknesses in
ongoing operation.
[0013] This object is also achieved by means of a device with the
features according to claim 7. Subsequently, a compensating device
is provided in the device, which, as previously explained with
respect to method claim 1, supports the compensation of the thermal
consequences and which has a temperature control device. In doing
so, the temperature control device is designed and configured using
control engineering for production of the aforementioned
compensating temperature profile in the preform, and the
compensating device furthermore has a preform alignment device for
the aligned insertion of the temperature-profiled preform in a mold
of a forming station. The temperature control device in this case
is designed and configured to impart a temperature profile to the
preform, which is not point-symmetrical in relation to the
longitudinal axis of the preform, in order to create a thermally
differentiated partial circumferential region in the preform. The
symmetrical observation relates to a section perpendicular to the
longitudinal axis of the preform; thus, the temperature
distribution is considered in the circumferential direction in this
sectional plane. The preform alignment device is, in turn, designed
and configured to insert the preform into the mold with such an
alignment that the thermally differentiated partial circumferential
region is facing in the radial direction. The explanations given in
the previous paragraph apply to the method herein accordingly.
[0014] The goal of the previously described device as well as the
previously described method in this case is to offset the early and
asymmetrical contact of a partial circumferential region of the
container bubble with the thermal effect occurring at the inner
wall of the mold due to a preceding corresponding and compensating
thermal differentiation of a partial circumferential region of the
preform.
[0015] Advantageous embodiments and details of this general
technical teaching according to the invention are indicated in the
dependent claims or result from the description of the figures.
[0016] It should be noted that the described and claimed
compensating thermal differentiation of the preforms is a
supplement to the known temperature conditioning; optionally, the
known preferential heating is also a supplement to this.
[0017] This results in various options for implementing the thermal
differentiation of a partial circumferential region of a preform
according to the invention. Thus, it is essentially possible, e.g.,
to choose between a targeted cooling or a targeted heating of the
thermally differentiated partial circumferential region. It is
essentially also possible to achieve the thermal differentiation of
a partial circumferential region in that the complementary regions
thereto are cooled or heated in a targeted manner. It is also
possible to purposefully cool a partial circumferential region and
to purposefully heat another region in order to achieve the thermal
differentiation of a partial circumferential region according to
the invention. Suitable heating mechanisms for the targeted heating
as well as suitable cooling devices for the targeted cooling are
known in the prior art, e.g., from the technical area of
temperature conditioning of preforms. Known heating and/or cooling
devices used for this purpose can also be used for the described
thermal differentiation according to the invention. For example,
radiant heaters emitting thermal radiation in the IR or NIR range
or cool-air or hot-air blowers are suitable.
[0018] The previously described thermal consequences of the
centrifugal force depend on whether the preform and/or the
container bubble developing therefrom or whether the inner wall of
the mold is at a higher temperature. If the inner wall of the mold
is, e.g., colder than the preform and/or the container bubble, the
thermal consequences would be an earlier and stronger cooling of
the container bubble in its region lying outward radially and
initially making contact with the inner wall of the mold. On the
other hand, if the inner wall of the mold is maintained at a higher
temperature than the container bubble, the thermal consequences
would be a heating of the container bubble in said region lying
outward radially. The cooling or heating occurring due to the
asymmetrical contact of the container bubble with the inner wall of
the mold would be offset by means of the suitable prior heating or
cooling measures on the preform. Compensation of cooling of the
container bubble in its region lying outward radially could exist,
e.g., from a targeted heating of the preform in this region or from
a targeted cooling of the remaining regions. It is also possible to
provide said targeted heating of a region and the targeted cooling
of the remaining region simultaneously.
[0019] From the aforementioned possibilities, it is considered to
be advantageous for the method as well as for the device that the
thermally differentiated partial circumferential region is heated
more strongly than the remaining circumferential regions of the
preform. The targeted heating of a partial circumferential region
is already known to one skilled in the art from the technical area
of so-called "preferential heating," however, not in the symmetry
according to the claim, and one skilled in the art can thus resort
to the known technology and known heating mechanisms. Furthermore,
the targeted heating is possible, e.g., by supplying heating
capacity by means of IR or NIR radiation. In doing so, this refers
to the absorption of radiation which occurs over the entire
thickness of the wall and thus throughout the entire wall volume. A
quicker and more direct input of thermal energy is advantageous,
e.g., as compared to blowing with a cooling medium, whereby
initially only the surface being blown at would be cooled, and the
cooling throughout the volume would then take place by means of
slower thermal processes.
[0020] In particular, it is advantageous in this case when the
thermally differentiated partial circumferential region is facing
radially outward after insertion of the preform into the mold of a
forming station. The compensating temperature profile is thereby
simpler to adjust and to determine, because there is a direct
geometric association between the thermally differentiated region
and the region initially making contact with the inner wall of the
mold. The area initially making contact with the inner wall of the
mold would also thereby be the thermally differentiated region.
[0021] The thermal consequences of the centrifugal force are
dependent on the circumferential speed of the working wheel. For
this reason, it is advantageous both for the device and for the
method when the compensation of the thermal consequences is
implemented dependent on the circumferential speed in that the
temperature profile imparted to the preform by the compensating
device is selected or regulated and/or controlled as a function of
the circumferential speed of the working wheel.
[0022] It would also be possible to arrange the imparting of the
compensating temperature profile explained in the previous
paragraphs to the preforms, e.g., between the heating device and
the forming station or between the infeed region into the forming
and filling machine and the heating device, e.g. on a transfer
wheel arranged in between. For example, the temperature control
device according to the claim could be arranged there, e.g., for
creating the compensating temperature profile. However, it is
proposed with advantage that the imparting of the compensating
temperature profile takes place in the heating zone by means of the
heating device for the preforms. The temperature control device
according to the invention would thus be arranged in the heating
zone. During pass-through of the heating device, the preform would
obtain both the temperature conditioning for the forming known in
the prior art as well as the imparting of a temperature profile in
the circumferential direction according to the invention for the
compensation of the thermal consequences of the centrifugal force,
namely the thermal differentiation of a circumferential region. The
heating mechanisms used for temperature conditioning could thereby
also optionally be used for creating the compensation temperature
profile. To this end however, the control and/or the regulation of
the known heating mechanisms must be modified or optionally the
preform would have to be moved differently than previously known,
e.g., during pass-through of the heating zone. The entire
temperature profile of the preform upon exiting the heating zone
would then basically be the superimposing of the known profile
based on the common temperature conditioning (optionally with
preferential heating) plus the temperature profile which is
imparted to the preform for the purposes of the compensation.
[0023] The partial circumferential region initially making contact
with the inner wall of the mold will have a partial circumferential
angle .PHI. of less than 180.degree.. For this reason, it is
preferable for the thermally differentiated partial circumferential
region to also have a partial circumferential angle .PHI. of less
than 180.degree., preferably less than 120.degree., further
preferably less than 90.degree..
[0024] The described compensation by means of targeted imparting of
a temperature profile to the preform in its circumferential
direction has a certain similarity to the known area of
preferential heating, with this being understood as generally the
nonuniform temperature control of preforms in the circumferential
direction thereof. With preferential heating, such type of
nonuniform temperature control with more strongly heated
circumferential regions and with less strongly heated
circumferential regions is applied when containers, the
cross-section thereof deviating from a circular shape, are to be
produced from the preforms. The deviation may exist, for example,
in that the containers are to be produced with an oval
cross-section or, for example, with a triangular or rectangular
cross-section. The temperature profile imparted to the preform
within the scope of the preferential heating in this case follows
the symmetry of the container to be produced, is point-symmetrical
with respect to the longitudinal axis of the preform in this case,
and does not support the compensation of thermal effects according
to the invention which are due to and specific for the hydraulic
forming of preforms on machines of a rotating design by means of
the introduction of a pressurized liquid forming fluid into a
preform. All of the non-generic documents regarding the prior art
addressed in the following relate to the blow-molding production of
containers from preforms by means of the introduction of a
pressurized gaseous forming fluid into a preform.
[0025] The blow-molding production of non-round containers is
described, e.g., in U.S. Pat. No. 3,892,830. Point-symmetrical
temperature conditioning by means of selective shading is indicated
in DE 33 14 106 A1. EP 0 620 099 B1 and DE 694 01 024 T2, with
similar content, disclose a combining of methods known from the
prior art for temperature conditioning of preforms. Furthermore, it
is known in the prior art to initially heat a preform in a first
heating section of a heating device in the circumferential
direction homogenously, that is uniformly, and subsequently to
create the temperature profile desired for preferential heating in
a second heating section in the circumferential direction. WO
97/32713 discloses such prior art with an incrementally functioning
rotational drive for the preforms. U.S. Pat. No. 5,853,775
discloses two heating sections with a likewise incrementally
circulating transport chain with a plurality of chain links, in the
form of transport mandrels, bearing preforms. Homogenous heating of
the preforms initially takes place in a first heating station and,
in a second heating station opposite the first station,
circumferentially profiled heating of the preforms takes place. In
both heating stations, the preforms are rotated by means of a chain
assigned to only the respective heating station. DE 10 2007 016 027
A1 teaches a device for preferential heating, in which a rotational
movement of the preforms is created by an extruded profile, which
interacts with a gear wheel of the transport means, which carries
the preforms through the heating zone and which, together with
other transport means, is connected to a circulating transport
chain. The extruded profile circulates around the heating zone
spaced apart from the transport chain and intermeshes with the gear
wheel of the transport means. In doing so, the extruded profile is
driven at a constant or varying circumferential speed.
[0026] A significant difference compared to the preferential
heating known in the prior art in this case is that the temperature
profile according to the invention compensating for the influence
of centrifugal force in the circumferential direction of the
preform is independent of the symmetry of the container to be
produced. With preferential heating, the symmetry of the
temperature profile imparted to the preform in the circumferential
direction follows the symmetry of the bottle to be produced, while
the compensating temperature profile according to the invention in
the circumferential direction may deviate from the symmetry of the
container to be produced and normally does deviate therefrom. The
method according to the invention and the device according to the
invention lead to a non-point-symmetrical circumferential
temperature profile and thus to a thermal differentiation of a
circumferential region of the preform. However, they can
advantageously be used during the production of point-symmetrical
containers, particularly in the production of containers with
n-fold rotational symmetry where n={2,3,4,6,8}, particularly during
the production of circular-symmetrical containers.
[0027] Additional advantages, features, and details of the
invention result from the exemplary embodiments described in the
following with reference to the schematic drawings. The following
is shown:
[0028] FIG. 1 a highly schematized representation of a forming and
filling device;
[0029] FIG. 2 a longitudinal section through a mold of a forming
station, in which a preform is stretched and expanded, with a
developing container bubble;
[0030] FIG. 3a a first exemplary embodiment of a temperature
control device according to the invention;
[0031] FIG. 3b a second exemplary embodiment of a temperature
control device according to the invention;
[0032] FIG. 4 a sketch related to a further exemplary embodiment of
the present invention with a preform alignment device in a top
view;
[0033] FIG. 5 a side view of a further exemplary embodiment of the
invention;
[0034] FIGS. 6a, 6b enlarged views of the exemplary embodiment in
FIG. 5 in the region of the alignment device for the preforms;
[0035] FIG. 7 a detailed view from FIG. 4 in the region of the head
wheel for the alignment device therein;
[0036] FIG. 8 perspective views of the details from FIG. 7;
[0037] FIG. 9 sectional views from above of the subject matter in
the left half of the picture from FIG. 8.
[0038] The structure of a combined forming and filling machine 10
essentially known from the prior art is shown in FIG. 1. The
representation shows the preferred design of such a filling device
10 in the form of a rotating machine with a rotating working wheel
110 supporting forming stations and/or forming and filling stations
16. Schematically represented preforms 14 are continuously fed to a
heating device 116 by an infeed device 112 with use of a transfer
wheel 114. In the region of the heating device 116, in which the
preforms 14 are transported along a heating zone and thermally
conditioned while doing so, the preforms 14 can be transported
depending on the application, for example, with their outlet
sections 22 upward in the vertical direction or downward in the
vertical direction. The heating device 116 is equipped, for
example, with heating mechanisms 118, which are arranged along a
transport mechanism 120 for forming the heating zone. For example,
a circulating chain with transport mandrels for retaining the
preforms 14 can be used as a transport mechanism 120. For example,
IR radiators or light-emitting diodes (LEDs) or NIR radiators are
suitable as heating mechanisms 118. Because such heating mechanisms
are known in various forms in the prior art and the design details
of the heating mechanism are not essential for the present
invention, a more detailed description can be omitted and reference
can be made to the prior art, particularly to the prior art related
to heating mechanisms of mold blowing and stretch mold blowing
machines.
[0039] After sufficient temperature control, also known as thermal
conditioning, the preforms 14 are transferred by a transfer wheel
122 to a working wheel 110, which is arranged so as to rotate, i.e.
can be circumferentially driven about a vertical machine axis MA,
and/or to forming and filling stations 16, which are arranged on
the working wheel 110 distributed around the circumference. The
working wheel 110 is equipped with a plurality of such forming and
filling station 16, in the region of which both forming of the
preforms 14 into the schematically shown containers 12 as well as
filling of the containers 12 with the intended content take place.
The forming of each container 12 in this case takes place
simultaneously with the filling, wherein the content serves as a
pressure medium during forming.
[0040] After the forming and filling, the containers 12 are taken
from the working wheel 110 by a removal wheel 124, further
transported, and supplied to an output zone 126. The working wheel
110 circulates continuously at a desired circumferential speed
during production operation. During a revolution, the insertion of
a preform 14 into a forming and filling station 16, the expansion
of the preform 14 into a container 12 including filling with a
content and optionally including stretching, in the event a
stretching rod is provided, and the removal of the container 12
from the forming and filling station 16 take place.
[0041] According to the embodiment in FIG. 1, it is further
optionally provided to feed schematically shown caps 130 to the
working wheel 110 by means of an input mechanism 128. It is hereby
also possible to implement a closing of the container 12 while
already on the working wheel 110 and to handle completely formed,
filled, and closed containers 12 using the removal device 124.
[0042] Various thermoplastic materials can be used as the material
for the preforms 14. Examples include polyethylene terephthalate
(PET), polyethylene (PE), polyethylene terephtalate (PEN), or
polypropylene (PP). The dimensions as well as the weight of the
preforms 14 are adapted to the size, the weight, and/or the shape
of the containers 12 to be produced.
[0043] A plurality of electrical and electronic components are
typically arranged in the region of the heating device 116.
Moreover, the heating mechanisms 118 are provided with
moisture-sensitive reflectors. Because a filling and forming of the
container 12 takes place in the region of the working wheel 110
while using the liquid content, it should be ensured that
unintentional entry of moisture is prevented in the region of the
heating device 116 to prevent electrical problems. This can take
place, for example, by means of a partition mechanism 132, which at
least offers spray protection.
[0044] Moreover, it is also possible to suitably adjust the
temperature of the transport elements for the preforms 14, said
transfer elements being used in the region of the transfer wheel
122, or to impact with pressurized gas such that adhering moisture
cannot reach the region of the heating device 116.
[0045] The preforms 14 and/or the containers 12 are preferably
handled using tongs and/or the outlet section 22 is handled, at
least in areas, by clamping mandrels or dowels impinging from the
interior or exterior. Such handling means are likewise well-known
from the prior art.
[0046] In a principally sectional view through a forming and
filling station 16 in addition to the molded container 12, FIG. 2
also shows the preform 14 in dashes and a developing container
bubble 15 schematically. In the exemplary embodiment shown, a
stretching of the preform 14 in the longitudinal direction X
thereof is provided by means of a stretching rod 11. In the process
state shown of the forming and filling process, the mold 13 of the
forming station 16 is in a closed state and the stretching rod 11
is moving until it reaches its lower end position. The stretching
of the preform 14 in the axial direction X is complete, while the
expansion transverse to the axial direction X is not yet complete
in reference to the container bubble 15. The mold 13, which is
formed from a mold base 4 and two halves of the mold sides, 5 and
6, encloses an inner cavity, which is terminated by the inner wall
of the mold 7, against which the preform 14 and/or the developing
container bubble 15 expands through the introduction of the content
3 under forming pressure. The pressurized feeding of the content 3
takes place by means of a forming and filling head 8, which has
been lowered so as to seal the outlet section 22 of the preform 14
and by means of which the content 3 is introduced, e.g., through
the stretching rod 11 and/or passed the stretching rod 11.
[0047] FIG. 3a shows a horizontal section through a preform 14
arranged in the region of a temperature-profile-creation device 36.
It can be seen that the temperature-profile-creation device 36 has
a radiant heater 37, e.g. an IR or NIR radiator, as well as a
reflector 38. In this embodiment, a circumference of the preform 14
has been divided into four angle ranges 14a, 14b, 14c, 14d. In the
circumferential direction, the temperature control of the angle
ranges 14a, 14b, 14c, 14d should take place such that one of these
ranges is thermally differentiated, thus obtains, e.g., a higher
temperature than the remaining ranges. In particular, it is
provided that the radiant heater 37 directly radiates the preform
14 only in angle range 14a, while the remaining angle ranges 14b,
14c, 14d do not experience any direct heat radiation. Accordingly,
angle range 14a with angle .PHI. of the preform 14 is provided with
a higher temperature than angle ranges 14b, 14c, 14d after impact
with the heat radiation. The size of the respective angle ranges
14a, 14b, 14c, 14d is selected at 90.degree. for each in the
example shown and can also be selected to deviate therefrom.
[0048] When implementing the desired thermally differentiated
circumferential region 14a of the preform 14, it would be possible
to maintain the preform 14 in a non-rotatable manner. However, it
is also possible to implement a rotation of the preform 14 about
its longitudinal axis 8 with an incremental movement or
continuously and, in doing so, to switch on or release the radiant
heater 37 in cycles when the circumferential region 14a is aligned
so as to face the radiant heater 37.
[0049] The temperature-profile-creation device 36 can be arranged,
e.g., in the heating device 116, e.g. at the end of the heating
zone, and resemble the heating mechanisms 118 provided in the
heating device 116. For example, it is possible to adjust the
temperature of the preform 14 in the circumferential direction
uniformly initially in advance and subsequently to create the
thermally differentiated region 14a with the help of the described
temperature-profile-creation device 36, e.g., in that a preform 14
is guided passed a heating mechanism 118 in a non-rotatable manner.
FIG. 3b shows another option for thermal differentiation of a
circumferential region 14a of a preform 14. A pre-tempered preform
14 in this case is moved along a cooling nozzle 53 in a
non-rotatable manner, from which a cooling gas flows onto the
circumferential region 14d. Air can be used for example. The
statements related to FIG. 3a regarding rotation of the preform 14
and arrangement of the cooling nozzle 53 in the heating device 116
apply here in a similar manner.
[0050] It is also conceivable to provide both cooling of a first
circumferential region, as explained by means of example in FIG.
3b, as well as heating of the circumferential region complementary
thereto, as explained in FIG. 3a. It is also conceivable to replace
the cooling nozzle 53 with a heating nozzle and to impact the angle
range 14a with hot air.
[0051] In a view from above, FIG. 4 shows a heating device 116
essentially known from the prior art with a
temperature-profile-creation device 36 according to the invention
for creating a thermally differentiated circumferential region 14a
of a preform 14. The circulating transport chain 50, composed of
multiple transport means 33, is indicated by individual chain links
33. This chain 50 is deflected via deflection wheels, which are not
shown in greater detail, and has a curved region 41 in the area of
this deflection and linear regions 42 lying in between. The preform
is inserted into the heating device 116 in the region of the head
wheel indicated by reference 34. FIG. 4 does not show the
corresponding transfer wheels for transforming preforms to the
heating device 116 and for removing the temperature-controlled
preforms after passing completely through the heating device 116 by
means of an almost complete circulation cycle of the transport
chain 50.
[0052] Multiple heating mechanisms 118 are provided in the linear
region 42 on the left in FIG. 4. Typical heating mechanisms 118 of
this type are constructed, for example, as heater boxes with
radiant heaters housed therein. Normally, multiple essentially
horizontally extending linear-shaped heating pipes emitting heat
radiation are arranged in this heating mechanism 118, with the
heating pipes being arranged distributed about the length of the
preform. These radiant heaters are normally arranged on one side of
the heater box and a reflector is normally arranged on an opposite
side of the heater box, the reflector being designed with high
reflection capacity for the heat radiation used. The preforms 14
are guided through by the transport means 33 in the region formed
between the radiant heaters and the reflector. In doing so, the
preforms 14 are moved continuously and continuously rotated about
their longitudinal axis in order to ensure the most uniform heating
possible about the circumference of the preforms 14. Uniform
temperature control can also take place in the axial direction of
the preform 14. However, it is also possible for certain elevation
regions of the preform 14 to be brought to a higher or a lower
temperature than the other elevation regions. In the left-hand
region, FIG. 4 shows five heater boxes 118 arranged next to one
another, in which this uniform heating of the preforms 14 in the
circumferential direction takes place, wherein this number can be
selected as desired.
[0053] There are also heater boxes 118, 36 located on the opposite
linear region 42 of the heating zone, through the heating device
116. The two heater boxes 118 the preforms 14 initially pass
through on this section of the heating zone are structurally
similar to the previously described heater boxes 118 for the
uniform circumferential temperature control of the preforms 14.
This is followed by a gap as well as two heater boxes 36 required
for the thermal differentiation of a partial circumferential region
14a of the preforms 14 further in the direction of the preform
movement, said boxes differing in their structure from the
previously mentioned heater boxes 118. In this case as well,
multiple radiant heaters are typically arranged on a first side of
the heater box 36. However, there is optionally no reflector
arranged on the opposite side of the heater box 36. This is
intended to ensure that the preforms 14 guided through these
thermal differentiation heater boxes 36 are not
temperature-adjusted equally on the two opposite sides. This can
also be achieved or further enhanced in that radiant heaters are
used, which emit a radiation with a high portion of the radiation
in a wavelength range which is absorbed by the preform material to
a higher degree than with the heater boxes 118 for the uniform
circumferential temperature control. In this manner, a desired
temperature profile can be created in the circumferential
direction, namely a circumferential region with an excellent
temperature, at present with a higher temperature, namely the
circumferential region facing the radiant heaters. The remaining
circumferential regions have a lower temperature, namely the
circumferential regions of the preform 14 facing in the direction
of movement and opposite the direction of movement and the
circumferential region facing away from the radiant heater.
[0054] FIG. 4 further shows the arrangement of an engagement
mechanism 45, which, in the exemplary embodiment shown, is designed
as a circumferentially guided engagement belt 46'. The upper
deflection region 49 of the engagement belt 46' is located between
the heating boxes 118 for the uniform circumferential temperature
control of the preforms 14 and those heating boxes 36 for the
thermal differentiation of a circumferential region. To this end,
one feed-in position, for example, is unoccupied for a heater box.
The lower deflection roller 48 for the engagement belt 46' is
arranged in the region of the head wheel 34. In particular, this
deflection roller 48 is designed such that the engagement belt 46'
partially follows the curved region 41 around the head wheel 34.
Furthermore, this deflection roller 48 is particularly formed so as
to shift in a manner such that the engagement belt 46' follows the
curved region 41 of the head wheel over a changing course. Details
regarding this are shown in FIG. 7 and explained in greater detail
in conjunction with FIG. 7, particularly the advantages thereby
achieved.
[0055] The engagement belt 46' has a belt drive 47 in the exemplary
embodiment shown. The engagement belt 46' is designed in this case
such that an engagement in the transport means 33 takes place such
that there is no rotation about the longitudinal axis of the
preforms when passing through the heater boxes 36 designed for
thermal differentiation. To this end, it is provided, for example,
that the engagement belt 46' runs at the same speed as the
transport chain 50. It is possible, for example, for a
synchronization to take place between the transport chain 50 and
the engagement belt 46'. It would also be conceivable, however, for
the engagement belt 46', for example, to not have its own drive but
rather, for example, carriers, which engage the transport chain 50
and are then carried along by the transport chain 50. In this
manner, the speed of the transport chain 50 and of the engagement
belt 46' can be evenly maintained in a simple manner.
[0056] FIG. 4 further shows a so-called mandrel rotary belt 51,
which ensures the uniform rotation of the preforms 14 about their
longitudinal axis when passing through the heater boxes 118 for
uniform circumferential temperature control. This mandrel rotary
belt 51 is guided by the transport chain 50 externally; in
alternative embodiment variations, it could also be guided
internally, and extends, at a slight distance, into the linear
regions 42 of the heating device 116, parallel to the transport
chain 50. This mandrel rotary belt 51 extends completely around the
transport chain 50 and is a first engagement mechanism. Such a
mandrel rotary belt 51 is already known in the prior art and
interacts, for example, with a gear wheel 52, which is arranged at
the respective transport means 33 and rolls off the mandrel rotary
belt 51. The circumferential speed of the mandrel rotary belt 51 is
selected in a ratio to the circumferential speed of the transport
chain 50 such that a relative speed exists so that the transport
means 33 bearing the preform 14 is placed into rotation about its
own axis due to the unwinding of the gear wheel 52 on the mandrel
rotary belt 51.
[0057] In the region between the heater boxes 118 for the uniform
circumferential temperature control and the heater boxes 36 for the
thermal differentiation of a circumferential region, this mandrel
rotary belt 51 is guided away from the transport chain 50 and the
mandrel rotary belt 51 is thereby out of engagement with the gear
wheels 52 of the transport means 33. This guiding away is provided
so that the second engagement mechanism 45 can engage the gear
wheel 52 without the mandrel rotary belt 51 showing a fault. To
this end, the mandrel rotary belt 51 is guided externally at the
second engagement mechanism 45 and at its deflection and guide
rollers 48, 49. Outside of the region of the heater boxes 36 for
the thermal differentiation of a circumferential region and after
the engagement belt 46' is returned for a complete circulation, the
mandrel rotary belt 51 again extends close to the transport chain
50 and again engages with the gear wheels 52 of the transport means
33 formed, e.g. as transport mandrels, in the left linear region 42
of the heating device 116.
[0058] The enlarged cutout from FIG. 4 shown in FIG. 7 shows the
engagement belt 46' in its extension in the region of the head
wheel 34. In the left linear region, the engagement belt 46', e.g.
a toothed belt, engages with the gear wheel 52 of the transport
mandrels of the transport chain 50, wherein other transport means
33 could also form the chain links of the transport chain 50 as
transport mandrels. This engagement is continued in a curved region
41 of the transport chain 50, and the engagement belt 46' extends
over a partial circumference at a corresponding angle a in this
curved region around the head wheel 34, before the belt 46' lifts
off of the gear wheels 52 and starts its return. In the linear
region 42, the engagement belt 46' and the transport chain 50 are
at the same speed and, due to the parallel arrangement of the two
belt and/or chain extensions, the preform 14 can be maintained in
this manner in a fixed circumferential angle position. However, as
soon as the curved region 41 starts, the transport chain 50 spreads
and the engagement belt 46' and the transport chain 50 run at a
different angular velocity on different radii r1, r2. For this
reason, a rotation of the transport means 33 and of the preform 14
being thereby retained takes place in this curved region 41 of the
head wheel 34. The angle of rotation is dependent, on one hand, on
the ratio of the rotation radii of the transport chain 50 and of
the engagement belt 46' and, on the other hand, on the angle a. Due
to movement of the respective position in the curved region 41, at
which the engagement belt 46' is placed out of engagement with the
gear wheel 52 of the transport mandrel 33, the rotation of the
preform 14 and/or of the transport mandrel 33 can be adjusted
specifically. For the purposes of this adjustment, a deflection
means 48 of the engagement belt 46' is implemented in this region
41 in an adjustable manner in order to specifically modify the
angle shown in FIG. 7. The targeted rotation of the preform 14
and/or of the transport mandrel 33 is desired so that the preform
14 is inserted into the forming station 16 at a certain alignment
so that, thus, the thermally differentiated circumferential region
of the preform 14 is at a certain orientation, for example, upon
the transfer to the working wheel 110 and into the molds of the
forming stations, e.g. so that the differentiated circumferential
region is lying outward radially or inward radially. The previously
described design is an example of a preform alignment device
according to the invention. The adjustment of such a desired
alignment of the preform 14 is supported by the targeted adjustment
of the angle a in FIG. 7 by means of shifting of a deflection
roller 48 of the engagement belt 46.
[0059] The engagement belt described in reference to FIGS. 4 and 7
could also be designed, e.g., as an engagement chain. This chain
would only have to be guided similarly to the engagement belt and
engage the engagement body and/or the gear wheel 52. Other
engagement mechanisms with the same functionality are also
possible.
[0060] An example of an engagement chain, which has a significantly
more complex structure in comparison to the previously mentioned
engagement chain according to the exemplary embodiment in FIGS. 4
and 7 and which optionally provides further functionalities, is
explained in the following, wherein, in a further variation from
the previous exemplary embodiment, it does not have its own
belt/chain drive and/or generally does not have its own drive for
the engagement mechanism but rather the following exemplary
embodiment provides for carrying of the engagement mechanism by
means of the conveyor chain. This should also be considered an
option which can be implemented in the previous exemplary
embodiment. Vice versa, a separate drive can be provided for the
engagement mechanism instead of a carrier and/or instead of a
carrying engagement in the conveyor chain in any of the exemplary
embodiments.
[0061] FIG. 5 shows a partial cutout and a perspective side view of
a second example of a second engagement mechanism 45'. This second
engagement mechanism 45' is substantially designed as a circulating
chain with multiple chain links. The first engagement mechanism 51
is also formed here in the form of a circulating toothed belt,
namely as a mandrel rotary belt. In the front right-hand region of
FIG. 5, a heater box 118 is shown, which is provided for the
uniform temperature control of a preform 14 in the circumferential
direction. Two heater boxes 36 are shown in the left region of FIG.
5, which are formed for the thermal differentiation of a
circumferential region of a preform 14. In the region in between,
which remains free due to the omission, for example, of a heater
box, the second engagement mechanism 45' is arranged. This
engagement mechanism 45' consists of an upper component 53 and a
lower component 54. The mandrel rotary belt 51 is guided away from
the transport chain 50 between these components 53, 54 and extends
on the exterior along the heater boxes 36. This selected division
of the engagement mechanism into two sections is purely optional
and enables, e.g., the provision of further functions in this
region of the heating device 116. Such further functions may be,
e.g., the implementation of sterilization by means of a
sterilization mechanism or, e.g., the provision of an inspection
device. With respect to the sterilization mechanism, reference is
made, e.g., to DE 10 2010 026 166 A1 and particularly here to FIG.
5 as well as to the statements therein regarding the advantages and
regarding the technical implementation of the sterilization of
preforms in the region of the heating zone of a heating device.
[0062] The upper component 53 and the lower component 54 of the
second engagement mechanism 45' are linked to a coordinated
rotational movement, which is not shown. It is also conceivable
here to provide both components 53, 54 with their own drives, which
function in a manner coordinated with one another, in order to
achieve a uniform and synchronized rotational movement. However, it
is also conceivable for only one of the two components 53, 54 to
have a drive and, for example, the other component to be driven by
means of a coupling motion. However, it is also possible for one or
both components to engage the transport chain 50 by means of
carriers and be carried along by the transport chain 50. This is
shown in FIGS. 6a and 6b by means of example. This embodiment
variant has the advantage that the individual chain links of the
engagement chain 45' automatically run at the same speed as the
links of the transport chain. Upon engagement of the engagement
elements 45' with the gear wheel 52 of the transport mandrel 33 and
upon the indicated same speed of the engagement mechanism 45' and
of the transport mandrel 33, this means that the inherent rotation
of the preform 14 about its longitudinal axis is suppressed.
Accordingly, the preform 14 can be guided with a fixed orientation
in the circumferential direction by means of the heater box 36
formed for the thermal differentiation of a circumferential region.
Because the mandrel rotary belt 51 is guided out of engagement with
the transport mandrel 33 in the region of the second engagement
mechanism 45', it is sufficient to end and to stop the mandrel
rotation in this region.
[0063] Essentially, it may be provided, e.g., that the carrier 44
has an engagement element, e.g. a blocking element, which engages
the rotary drive body 52 of the transport mandrel 33 in a manner to
prevent a rotation, as soon as the carrier 44 is placed in carrying
engagement with the transport chain 50 in a cam-controlled manner.
The blocking elements would then be moved with the carriers and,
e.g., simultaneously placed in engagement and out of engagement. To
this end however, the lift-off of the mandrel rotary belt 51 shown
in FIG. 6a must take place, e.g., earlier than as shown there. It
is also possible for an engagement element of the engagement
mechanism 45' to be arranged on each chain link, separate from the
carrier 44 but in a similar manner to the carrier 44, with the
engagement element likewise being placed in engagement and out of
engagement, in a cam-controlled manner, with the rotary drive body
52 of the transport mandrel 33. This can take place at a different
time than the carrier engagement with the conveyor chain 50. This
would also make it possible to select the number of carriers 44 to
be different than the number of engagement elements. It is not
necessary for each chain link to have a carrier; this is purely
optional. It is only necessary that a sufficient number of carriers
be arranged distributed over the chain length in order to ensure
continuous carriage. To this end however, 3 or 4 uniformly
distributed carriers would be sufficient.
[0064] FIGS. 6a and 6b show how the carriers 44 discussed in the
previous paragraph can be formed in a special embodiment, with
omission of the upper component. The lower chain unit 54 has
carriers 44 that can be moved in the radial direction, which are
held, e.g., spring-loaded in a position pulled radially inward.
Upon reaching an external control curve 43, the carriers 44 are
pressed radially outward and reach traction engagement with the
transport means 33 of the transport chain. Such a solution is
considered to be advantageous, because the carriers 44 cannot
simply swivel into the linearly moved transport chain 50. The
engagement of the carriers 44 can take place, e.g., only in the
linear circumferential region 42.
[0065] FIG. 8 shows a further detail of a second engagement
mechanism 45''. This engagement mechanism 45'' consists of multiple
engagement elements 63, which are formed by an external control
curve 56 in a cam-controlled manner. In a first region 57 of this
control curve 56, the engagement elements 63 are out of engagement
with the gear wheel 52 of the transport mandrel 33. In a second
region 58 of the control curve 56, a swivel lever 59 is actuated,
which has inner toothing 60 and which drives a pinion 61. The
details regarding this are more easily seen in FIG. 9. In
particular, it can be seen that this pinion 61 sits on a common
shaft 62 with a belt pulley segment 63. The swivel movement of the
swivel lever 59 leads to a rotation of the pinion 61. The rotation
of the pinion 61 is matched by the belt pulley segment 63. In the
first region 57 of the control curve 56, this belt pulley segment
63 is out of engagement with the gear wheel 52 of the transport
mandrel 33. In the second region 58 of the control curve 56, the
swivel lever 59 swivels, the pinion 61 thereby rotates, and the
belt pulley segment 63 thereby reaches engagement with the gear
wheel 52 of the transport mandrel 33. Retaining this position means
that the gear wheel 52 is held, and the transport mandrel 33 and
the preform 14 being held thereby are maintained in a non-rotatable
manner.
[0066] This design further enables the transport mandrel 33 and the
preform 14 being held thereby to be maintained not only in a
non-rotatable manner but specifically to twist about a certain
angle of rotation, namely when the swivel movement of the swivel
lever 59 is designed such that the belt pulley segment 63 not only
holds the gear wheel 52 in a certain position but rather the swivel
lever 59 could be more strongly swiveled, for example, in a third
region of the control curve 56 in that the pinion 61 thereby
rotates even further and the belt pulley segment 63 thereby rotates
even further such that, as a result of the comb-like engagement
with the gear wheel 52 of the transport mandrel 33, this gear wheel
52 and thus also the transport mandrel 33 is twisted about a
certain angle. This can be used, e.g., as a preform alignment
device, because the preform 14 should be inserted into the forming
station 16 in a certain alignment and must possibly have to be
rotated specifically for this.
[0067] A plurality of further suitable alignment devices for
preforms are known in the prior art, e.g., devices interacting with
alignment structures on the preform or with optical markings on the
preform. WO 2016/180510 A1 shows examples and mentions examples in
the prior art, which are essentially suitable also as preform
alignment devices for the present invention in order to align the
thermally differentiated circumferential region of the preform in
the desired manner for transfer to the forming stations. Reference
is explicitly made with regard to this to the content of WO
2016/180510 A1 and to the content of the documents mentioned
therein as the prior art.
* * * * *