FIELD OF THE INVENTION
[0001] The invention generally relates to the processing of containers, such as bottles,
which are produced by blow molding or stretch-blow molding from preforms made of plastic
(mostly thermoplastic, e.g. PET) material. More specifically but not exclusively,
the invention relates to the processing of hot-fill containers, i.e. containers filled
with a hot pourable product (typically a liquid), the term "hot" meaning that the
temperature of the product is higher than the glass transition temperature of the
material, in which the container is made. Typically, hot filling of PET containers
(the glass transition temperature of which is of about 80°C) is conducted with products
at a temperature comprised between about 85°C and about 100°C, typically at 88°C.
BACKGROUND OF THE INVENTION
[0003] According to Denner, the pressure panel is movable between an outwardly-inclined
position and an inwardly-inclined position to compensate for a change of pressure
inside the container. In order to alleviate all or a portion of the vacuum forces
within the container, the pressure panel is moved from the outwardly-inclined position
by a mechanical pusher after the container has been capped and cooled, in order to
force the pressure panel into the inwardly-inclined position.
[0004] Tests conducted on such a container revealed that the effort to be applied on the
container bottom to achieve inversion of the diaphragm is important and therefore
requires a large mechanical pusher to be mounted along the container manufacturing
line.
SUMMARY OF THE INVENTION
[0005] It is a purpose of the invention to provide a solution to facilitate inversion of
the diaphragm.
[0006] It is another purpose of the invention to provide a method for processing containers,
permitting diaphragm inversion with less effort.
[0007] It is yet another purpose of the invention to provide a machine for processing containers,
including a movable pusher of smaller dimensions and/or requiring less power to permit
diaphragm inversion.
[0008] It is therefore provided, in a first aspect, a method for processing a container
provided with:
- a sidewall,
- a neck defining an opening,
- and a base including a standing ring and a central invertible diaphragm, said diaphragm
having a symmetry around a main axis and being deformable with respect to the sidewall
between a lower position, wherein said diaphragm projects outwardly with respect to
the container, and an upper position wherein said diaphragm projects inwardly with
respect to the container,
said method including the step of exerting on the diaphragm, by means of a movable
pusher, an inversion effort along an effort axis to invert the diaphragm from its
lower position to its upper position, wherein the effort axis is distinct from the
main axis.
[0009] Accordingly, the diaphragm is distorted asymmetrically, the distortion starting with
an initiator portion and spreading around the container main axis, whereby the effort
required to achieve inversion is lower than in the known techniques.
[0010] In one embodiment, the effort axis is spaced from the main axis.
[0011] The effort axis is for example substantially parallel to the main axis and spaced
therefrom of a distance comprised between 2 mm and 10 mm.
[0012] In an alternate embodiment, the effort axis is tilted with respect to the main axis.
[0013] The effort axis is for example tilted with respect to the main axis of an angle comprised
between 3° and 15°.
[0014] The method may further comprise the steps of:
- filling the container through said opening with a pourable product, the diaphragm
being in its lower position;
- closing the container at its neck with a cap.
[0015] The steps of filling and closing the container preferably precede the step of inverting
the diaphragm.
[0016] It is provided, in a second aspect, a machine for processing containers each including:
- a sidewall,
- a neck defining an opening,
- and a base including a standing ring and a central invertible diaphragm, said diaphragm
having a symmetry around a main axis and being deformable with respect to the sidewall
between a lower position, wherein said diaphragm projects outwardly with respect to
the container, and an upper position wherein said diaphragm projects inwardly with
respect to the container,
this machine including:
- a container supporting frame including a hollow support ring for engaging a container
base;
- a pusher movable with respect to the container supporting frame, capable of coming
into abutment with the container base through the supporting frame, said pusher being
capable of exerting an inversion effort along an effort axis onto the container base,
distinct from the main axis;
- an actuator for slidingly moving the pusher frontwards towards the container base
through the supporting frame, and backwards,
[0017] The actuator is e.g. an electric or magnetic actuator, including an electric or magnetic
motor, or a hydraulic or pneumatic cylinder including a cylinder housing, a piston
and a rod fixed to the piston, and the pusher is mounted onto the rod.
[0018] The above and other objects and advantages of the invention will become apparent
from the detailed description of preferred embodiments, considered in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019]
FIG.1 is a partial cut view showing a machine for processing containers, including a pusher
for inverting a diaphragm provided on a container base, in a first embodiment.
FIG.2 is an enlarged detailed view showing the machine of FIG.1, in a state preceding an inversion of the diaphragm.
FIG.3 is a view similar to FIG.2, showing the machine during inversion of the diaphragm.
FIG.4 is a view similar to FIG.2 and FIG.3, showing the machine in a state where inversion of the diaphragm is complete.
FIG.5 is a partial cut view showing a machine for processing containers, including a pusher
for inverting a diaphragm provided on a container base, in a second embodiment.
FIG.6 is an enlarged detailed view showing the machine of FIG.5, in a state preceding an inversion of the diaphragm.
FIG.7 is a view similar to FIG.6, showing the machine during inversion of the diaphragm.
FIG.8 is a view similar to FIG.6 and FIG.7, showing the machine in a state where inversion of the diaphragm is complete.
DETAILED DESCRIPTION
[0020] Shown on
FIG.1 is a container
1 made by blow molding or stretch blow molding from a preform made of plastic such
as PET. In a preferred though not exclusive embodiment, the container
1 is a hot-fill container, i.e. it has undergone, during the blow molding process,
a heat set phase in order to increase the resistance of the container
1 to thermal stresses undergone during a filling step with a hot product, "hot" meaning
that the temperature of the product is higher than the glass transition temperature
of the material. In the case of PET, which has a glass transition temperature of about
80°C, the hot pourable product has for example a filling temperature in a range of
about 85-95°C. Examples of hot pourable liquid products include (but are not limited
to) tea, fruit juices, sports drinks.
[0021] The container
1 includes an open cylindrical threaded upper portion or neck
2, which terminates, at an upper end thereof, by an opening or mouth
3. Below the neck
2, the container
1 includes a shoulder
4 of increasing diameter in a direction opposite to the neck
2.
[0022] Below the shoulder
4, the container
1 has a sidewall
5, which is substantially cylindrical around a container main axis
X. The sidewall
5 may, as depicted in
FIG.1, include annular stiffening ribs
6 capable of resisting thermal and mechanical stresses undergone by the container
1 during filling, capping and subsequent handling.
[0023] At a lower end of the sidewall
5, the container
1 has a base
7, which closes the container
1 and allows it to be normally put on a planar surface such as a table when used by
a final customer.
[0024] The container base
7 includes a standing ring
8, which may be a high standing ring as it will be explained later, and a central invertible
diaphragm
9, which has a symmetry around the main axis
X and is deformable with respect to the sidewall
5 between an outwardly-inclined (or lower) position shown on
FIG.1-2 and
FIG.5-6, wherein the diaphragm
9 projects outwardly with respect to the container
1, and an inwardly-inclined (or upper) position, shown on
FIG.4 and
FIG.8, wherein the diaphragm
9 projects inwardly with respect to the container
1.
[0025] The container
1 is blow molded with the diaphragm
9 in its lower position. As will be explained in further details below, the diaphragm
9 is capable of being mechanically forced upwards (i.e. inwards with respect to the
container
1) after the container
1 has been filled with a pourable product, capped and cooled down, in order to compensate
for the vacuum generated by the cooling of the product and to increase the overall
rigidity of the filled container
1, for the benefits of container handling and customer quality perception.
[0026] The standing ring
8 connects to the sidewall
5 of the container at a lower end portion
10 thereof. The standing ring
8 has a support flange
11 adjacent and substantially perpendicular to the lower end portion
10 of the sidewall
5, and a cylindrical or frustoconical inner portion
12 which connects the support flange
11 to the diaphragm
9. The support flange
11 is also substantially perpendicular to the container main axis
X.
[0027] In a preferred embodiment, the lower end portion
10 of the sidewall
5 has, when viewed in transversal section as shown on
FIG.2 and
FIG.3, the shape of an arch with a concavity turned inward with respect to the container
1, whereby the outer diameter of the support flange
11 is smaller than the overall diameter of the sidewall
5.
[0028] As depicted, the inner portion
12 preferably has the shape of a frustum of a cone and, when viewed in transversal section
as shown on
FIG.2, inclines inwardly with respect to the container
1, with a draft angle.
[0029] The cone shape of the inner portion
12 provides a vault stiffening and locking function to the diaphragm
9 in its inverted position (shown in
FIG.4 and
FIG.8), whereby the restriction of diameter of the inner portion
12 at its junction with the diaphragm
9 prevents the latter to articulate back from its inverted position with respect to
the inner portion
12. As a result, re-inversion of the diaphragm
9 back to its initial outwardly-inclined position under the mere hydrostatic pressure
of the poured product is prevented.
[0030] In the depicted example, the inner portion
12 has an axial extension, which is important with respect to the outer diameter of
the support flange
11, hence the expression "high standing ring" to name the standing ring
8. More specifically, the axial extension (or height) of the inner portion
12 is greater than 1/10 of the outer diameter of the support flange
11, and preferably comprised between 1/10 and 1/5 of the outer diameter of the support
flange
11.
[0031] In the blown (and filled) configuration of the container
1 depicted on
FIG.1, FIG.2, FIG.5 and
FIG.6, the invertible diaphragm
9 extends outwards in a frusto-conical shape from an outer edge
13, where the diaphragm
9 connects to an upper end of the inner portion
12, to an inner edge
14, where the diaphragm
9 connects to a central upwardly protruding recess
15. The geometric center of the recess
15 is located on the container main axis
X.
[0032] Also in the blown configuration of the container
1, the axial extension, or height, of the diaphragm
9, is such that the inner edge
14 of the diaphragm
9 extends slightly above a support plane defined at the junction between the support
flange
11 and the lower end portion
10 of the sidewall
5. In other words, the height of the diaphragm
9 is slightly lower than the height of the high standing ring
8.
[0033] After the container
1 has been blow molded, it is filled through its opening
3 with a (possibly hot) pourable product
16 (shown by a dotted pattern in
FIG.1 to
FIG.8), the diaphragm
9 remaining in its lower position.
[0034] Then the container
1 is closed at its neck
2 with a cap
17, which is forced down and screwed onto the neck
2.
[0035] The filled and capped container
1 may then undergo a cooling step for recovering an average atmospheric temperature,
e.g. of about 20°C.
[0036] Then, the container
1 is submitted to a diaphragm inversion, whereby the diaphragm
9 is moved from its lower position to its upper position.
[0037] Diaphragm inversion is conducted by a container processing machine
18, which may be a stand-alone machine but which, in a preferred embodiment, is part
of a container labeling machine configured for applying a label on the sidewall
5 of each container
1. As the present description is centered on the diaphragm inversion, the whole labeling
machine will not be disclosed.
[0038] The processing machine
18 may comprise a carrousel rotatably mounted on a fixed support structure, such carrousel
including a plurality of identical peripheral processing units
19 displaced along a circular path.
[0039] Since processing units
19 are identical, only one will be disclosed in detail hereinafter for the sake of clarity
and simplicity.
[0040] The processing unit
19 comprises a container supporting frame
20 including a hollow support ring
21 for engaging a container base
7. In the depicted example, the support ring
21 has an annular plate
22 and a tubular outer wall
23, whereby plate
22 and outer wall
23 together form a counter print of at least the support flange
11 and the lower end portion
10 of the container sidewall
5.
[0041] The supporting frame
20 (and more specifically the plate
22 and outer wall
23) is (are) centered on a main axis, which, when a container
1 is located on the supporting frame
20, merges with the container main axis
X. In the following,
X denotes both the container main axis and the supporting frame main axis.
[0042] The processing unit
19 further includes a container retaining member
24 for rigidly retaining the container
1 in vertical position with its base
7 located within the support ring
21 while the diaphragm
9 is being inverted.
[0043] In the depicted example, the retaining member
24 is provided with a conical head
25 suitable for vertically coming into abutment with the cap
17 along the main axis
X.
[0044] The processing unit
19 further includes a mechanical pusher
26 movable with respect to the supporting frame
20, capable of coming into abutment with the container base
7 through the supporting frame
20 for inverting the diaphragm
9.
[0045] The processing unit
19 further includes an actuator
27 for slidingly moving the pusher
26 along a displacement axis
Y, both frontwards (i.e. upwards) towards the container base
7 through the supporting frame
20 in order to achieve inversion of the diaphragm
9, and backwards (i.e. downwards) thereafter, to be ready for another inversion cycle.
[0046] In the depicted example it can be seen that the actuator
27 is a hydraulic or pneumatic cylinder, preferably of the two-way type.
[0047] The actuator
27 has a cylinder housing
28, a piston
29 and a rod
30 fixed to the piston
29, with the pusher
26 mounted onto the rod
30. In the depicted example, the pusher
26 is integral with the rod
30, but in an alternate embodiment the pusher
26 may be fixed (e.g. screwed) to a distal end of the rod
30.
[0048] In a known manner, the actuator
27 has a closure head
31 and a closure bottom
32. The piston
29 defines within the actuator
27 a front chamber
33 around the rod
30 and a back chamber
34 opposite to the rod
30, whereby the front chamber
33 is mainly defined between the piston
29 and the closure head
31 whereas the back chamber
34 is mainly defined between the piston
29 and the closure bottom
32.
[0049] As depicted in
FIG.2 and
FIG.6, the back chamber
34 is in fluidic connection, through a bottom fluid port
35 formed in the closure bottom
32, with a directional control valve (DCV)
36 linked to a source
37 of fluid (such as air or oil) under pressure.
[0050] In a preferred embodiment, the front chamber
33 is also in fluidic connection, through a front fluid port
38, to the DCV
36 (which is here of the 5/2 type: 5 ports, 2 spool positions), preferably through a
flow restrictor
39. This allows for a speed regulation of the piston
29 (and hence of the pusher
26) during actuation, i.e. during inversion of the diaphragm
9.
[0051] To achieve inversion of the diaphragm
9 from its lower position to its upper position, the pusher
26 exerts on the diaphragm
9 an inwardly (or upwardly) oriented inversion effort
E along an effort axis
Z, which:
- passes through a contact point between the pusher 26 and the container base 7 (in case pusher 26 contacts the container base 7 in an area, the contact point is regarded as the geometric center of this contact
area),
- is parallel to the displacement axis Y,
- is distinct from the main axis X.
[0052] In a first embodiment, depicted on
FIG.1 through
FIG.4, the effort axis
Z is spaced from the main axis
X.
[0053] More specifically, in the depicted example, the actuator
27 is such mounted with respect to the container supporting frame
20 that the displacement axis
Y and the main axis
X are collinear, and the pusher
26 has a tip
40, which protrudes from the rod
30 and which is shifted laterally with respect to the displacement axis
Y (and hence with respect to the main axis
X) by a distance
D. In a preferred embodiment, distance
D is of several millimeters, e.g. comprised between 2 mm and 10 mm.
[0054] In this first embodiment, the pusher
26 contacts the container base
7 at a contact point, which is shifted laterally with respect to the main axis
X by the same distance
D.
[0055] Accordingly, under the thus shifted inversion effort
E, the central recess
15 is swiveled and the diaphragm
9 is first asymmetrically distorted at an initiator portion
41, which bends inwards, see
FIG.3. As inversion effort
E is maintained, distortion spreads from the initiator portion
41 around the main axis
X, whereby the whole diaphragm
9 inverts to its upper position, see
FIG.4.
[0056] In a second embodiment, depicted on
FIG.5 through
FIG.8, the effort axis
Z is tilted with respect to the main axis
X by an angle
A. Angle
A is preferably comprised between 3° and 15°. In the depicted example, angle
A is of about 5°.
[0057] More specifically, in the depicted example, the actuator
27 is such mounted with respect to the container supporting frame
20 that the displacement axis
Y is tilted with respect to the main axis
X, and the pusher
26 has a tip
40', which is aligned with the rod
30.
[0058] In this second embodiment, the pusher
26 contacts the container base
7 at a contact point, which is substantially at the geometric center thereof. In an
alternate embodiment, the pusher
26 may contact the container base
7 at a contact point, which is shifted laterally with respect to the main axis
X.
[0059] When the pusher is applied against the container base
7, it generates an inversion effort
E, which is directed upwards along the tilted effort axis
Z and hence swivels the central recess
15 as in the first embodiment. The diaphragm
9 is first asymmetrically distorted at an initiator portion
41, which bends inwards, see
FIG.7. As inversion effort
E is maintained, distortion spreads from the initiator portion
41 around the main axis
X, whereby the whole diaphragm
9 inverts to its upper position, see
FIG.8.
[0060] Although the contact point may move during the inversion process, orientation of
the effort axis
Z remains substantially the same.
[0061] As already stated, starting from the raw blown container
1, the whole processing of the container
1 comprises the following steps:
- filling the container 1 through its opening 3 with pourable product 16, the diaphragm 9 being in its lower position;
- closing the container 1 at its neck 2 with cap 17,
- and then, inverting the diaphragm 9 with the processing unit 19, as disclosed hereinbefore by either embodiment.
[0062] In the filling step, the container
1 is normally not fully filled, so that an empty volume (also called headspace)
42 (of air or another gas such as nitrogen) remains between the product
16 and the cap
17. Depending upon the reliability of the filling machine, the volume of poured product
16 may vary from one container
1 to another. As a consequence, the headspace
42 may also vary from one container
1 to another, although the headspace
42 should always be substantially equal in volume to a reference headspace left by the
correct volume of dispensed product.
[0063] During inversion of the diaphragm
9, the product
16, which is virtually incompressible, is displaced upwardly, whereby the gas (generally
air) enclosed in the headspace
42 is compressed by a volume substantially equal to the volume (so-called extraction
volume) swept by the diaphragm
9 during its inversion, between its lower and upper positions.
[0064] Spacing or tilting the effort axis
Z with respect to the main axis
X facilitates inversion of the diaphragm
9, since distortion of the latter is progressive, starting from a localized initiator
portion
41 before spreading to the whole diaphragm
9.
[0065] Accordingly, less effort is required to be applied onto the diaphragm
9. This saves power and permits to use lighter and smaller actuator
27 and pusher
26 with respect to the known techniques.
[0066] Various alternate embodiments may be provided within the scope of the present disclosure.
[0067] For instance, the hydraulic or pneumatic actuator
27 may be replaced by an electric or magnetic actuator, including an electric or magnetic
motor.
[0068] In an alternate process, the step of inverting the diaphragm
9 is achieved before the filling and closing steps.
1. Method for processing a container
(1) provided with:
- a sidewall (5),
- a neck (2) defining an opening (3),
- and a base (7) including a standing ring (8) and a central invertible diaphragm (9), said diaphragm (9) having a symmetry around a main axis (X) and being deformable with respect to the sidewall (5) between a lower position wherein said diaphragm (9) projects outwardly with respect to the container (1), and an upper position wherein said diaphragm (9) projects inwardly with respect to the container (1),
said method including the step of exerting on the diaphragm
(9), by means of a movable pusher
(26), an inversion effort
(E) along an effort axis
(Z) to invert the diaphragm
(9) from its lower position to its upper position, said method being
characterized in that the effort axis
(Z) is distinct from the main axis
(X).
2. Method according to claim 1, wherein the effort axis (Z) is spaced from the main axis (X).
3. Method according to claim 2, wherein the effort axis (Z) is substantially parallel to the main axis (X), the distance (D) between the effort axis (Z) and the main axis (X) being comprised between 2 mm and 10 mm.
4. Method according to claim 1 or claim 2, wherein the effort axis (Z) is tilted with respect to the main axis (X).
5. Method according to claim 4, wherein the effort axis (Z) is tilted with respect to the main axis (X) of an angle (A) comprised between 3° and 15°.
6. Method according to any of the preceding claims, further comprising the steps of:
- filling the container (1) through said opening (3) with a pourable product, the diaphragm (9) being in its lower position;
- closing the container (1) at its neck (2) with a cap (17).
7. Method according to claim 6, wherein the steps of filling and closing the container
(1) precede the step of inverting the diaphragm (9).
8. Machine
(18) for processing containers
(1) each including:
- a sidewall (5),
- a neck (2) defining an opening (3),
- and a base (7) including a standing ring (8) and a central invertible diaphragm (9), said diaphragm (9) having a symmetry around a main axis (X) and being deformable with respect to the sidewall (5) between a lower position, wherein said diaphragm (9) projects outwardly with respect to the container (1), and an upper position, wherein said diaphragm (9) projects inwardly with respect to the container (1),
this machine
(18) including:
- a container supporting frame (20) including a hollow support ring (21) for engaging a container base (7);
- a pusher (26) movable with respect to the container supporting frame (20), capable of coming into abutment with the container base (7) through the supporting frame (20), said pusher (26) being capable of exerting an inversion effort (E) along an effort axis (Z) onto the container base (7);
- an actuator (27) for slidingly moving the pusher (26) frontwards towards the container base (7) through the supporting frame (20), and backwards;
characterized in that the effort axis (Z) is distinct from the main axis (X).
9. Machine (18) according to claim 8, wherein the effort axis (Z) is spaced from the main axis (X).
10. Machine (18) according to claim 9, wherein the effort axis (Z) is substantially parallel to the main axis (X), the distance (D) between the effort axis (Z) and the main axis (X) being comprised between 2 mm and 10 mm.
11. Machine (18) according to claim 8 or claim 9, wherein the effort axis (Z) is tilted with respect to the central axis (X).
12. Machine (18) according to claim 11, wherein the effort axis (Z) is tilted with respect to the main axis (Z) of an angle (A) comprised between 3° and 15°.
13. Machine (18) according to any of claims 8-12, wherein said actuator is an electric or magnetic
actuator, including an electric or magnetic motor.
14. Machine (18) according to any of claims 8-12, wherein said actuator (27) is a hydraulic or pneumatic cylinder including a cylinder housing (28), a piston (29) and a rod (30) fixed to the piston (29), and wherein said pusher (26) is mounted onto the rod (30).
Amended claims in accordance with Rule 137(2) EPC.
1. Method for processing a container
(1) provided with:
- a sidewall (5),
- a neck (2) defining an opening (3),
- and a base (7) including a standing ring (8) and a central invertible diaphragm (9), said diaphragm (9) having a symmetry around a main axis (X) and being deformable with respect to the sidewall (5) between a lower position wherein said diaphragm (9) projects outwardly with respect to the container (1), and an upper position wherein said diaphragm (9) projects inwardly with respect to the container (1),
said method including the steps of
- filling the container (1) through said opening (3) with a pourable product, the diaphragm (9) being in its lower position ,
- closing the container (1) at its neck (2) with a cap (17),
- exerting on the diaphragm (9), by means of a movable pusher (26), an inversion effort (E) along an effort axis (Z) to invert the diaphragm (9) from its lower position to its upper position, said method being characterized in that the effort axis (Z) is distinct from the main axis (X).
2. Method according to claim 1, wherein the effort axis (Z) is spaced from the main axis (X).
3. Method according to claim 2, wherein the effort axis (Z) is substantially parallel to the main axis (X), the distance (D) between the effort axis (Z) and the main axis (X) being comprised between 2 mm and 10 mm.
4. Method according to claim 1 or claim 2, wherein the effort axis (Z) is tilted with
respect to the main axis (X).
5. Method according to claim 4, wherein the effort axis (Z) is tilted with respect to the main axis (X) of an angle (A) comprised between 3° and 15°.
6. Method according to claim 1-5, wherein the steps of filling and closing the container
(1) precede the step of inverting the diaphragm (9).
7. Machine
(18) for processing containers (
1) each including:
- a sidewall (5),
- a neck (2) defining an opening (3),
- and a base (7) including a standing ring (8) and a central invertible diaphragm (9), said diaphragm (9) having a symmetry around a main axis (X) and being deformable with respect to the sidewall (5) between a lower position, wherein said diaphragm (9) projects outwardly with respect to the container (1), and an upper position, wherein said diaphragm (9) projects inwardly with respect to the container (1),
- each container (1) being filled through said opening (3) with a pourable product, the diaphragm (9) being in its lower position, each container (1) being then closed at its neck (2) with a cap (17),
this machine
(18) including:
- a container supporting frame (20) including a hollow support ring (21) for engaging a container base (7);
- a pusher (26) movable with respect to the container supporting frame (20), capable of coming into abutment with the container base (7) through the supporting frame (20), said pusher (26) being capable of exerting an inversion effort (E) along an effort axis (Z) onto the container base (7);
- an actuator (27) for slidingly moving the pusher (26) frontwards towards the container base (7) through the supporting frame (20), and backwards;
characterized in that the effort axis
(Z) is distinct from the main axis
(X).
8. Machine (18) according to claim 7, wherein the effort axis (Z) is spaced from the main axis (X).
9. Machine (18) according to claim 7, wherein the effort axis (Z) is substantially parallel to the main axis (X), the distance (D) between the effort axis (Z) and the main axis (X) being comprised between 2 mm and 10 mm.
10. Machine (18) according to claim 8 or claim 9, wherein the effort axis (Z) is tilted with respect to the main axis (X).
11. Machine (18) according to claim 10, wherein the effort axis (Z) is tilted with respect to the main axis (X) of an angle (A) comprised between 3° and 15°.
12. Machine (18) according to any of claims 7-11, wherein said actuator is an electric or magnetic
actuator, including an electric or magnetic motor.
13. Machine (18) according to any of claims 7-11, wherein said actuator (27) is a hydraulic or pneumatic cylinder including a cylinder housing (28), a piston (29) and a rod (30) fixed to the piston (29), and wherein said pusher (26) is mounted onto the rod (30).