U.S. patent application number 09/402459 was filed with the patent office on 2001-11-15 for method for making an aerosol housing with threaded neck.
Invention is credited to FLECHEUX, FRANCK, GRANGER, JACQUES, SCHNEIDER, BERNARD.
Application Number | 20010040167 09/402459 |
Document ID | / |
Family ID | 9523596 |
Filed Date | 2001-11-15 |
United States Patent
Application |
20010040167 |
Kind Code |
A1 |
FLECHEUX, FRANCK ; et
al. |
November 15, 2001 |
METHOD FOR MAKING AN AEROSOL HOUSING WITH THREADED NECK
Abstract
Process for manufacturing a metal can (1) equipped with a
threaded neck on which any type of removable head can be fitted,
comprising at least the following steps: a) production of a can
with a bottom and a cylindrical or shaped wall b) formation of a
neck (4) at the open end of the can c) use of a ring (5) equipped
with a spindle hole (52) and a thread (54) over its outer surface
(55), and sleeve fitting of the spindle hole (52) in the said ring
(5) around the neck (4) formed in the previous step, and
characterized in that it also includes the following step: d)
plastic expansion of the said neck (4), the diameter of the outer
surface (42) of the neck (4) being expanded to exceed the value of
the inner diameter of the spindle hole (52) of the ring (5) when at
rest.
Inventors: |
FLECHEUX, FRANCK;
(BELLEGARDE, FR) ; GRANGER, JACQUES; (LIBOURNE,
FR) ; SCHNEIDER, BERNARD; (SAINTE MENEHOULD,
FR) |
Correspondence
Address: |
DENNISON MESEROLE SCHEINER & SCHULTZ
1745 JEFFERSON DAVIS HIGHWAY
SUITE 612
ARLINGTON
VA
222023417
|
Family ID: |
9523596 |
Appl. No.: |
09/402459 |
Filed: |
October 8, 1999 |
PCT Filed: |
February 23, 1999 |
PCT NO: |
PCT/FR99/00399 |
Current U.S.
Class: |
220/634 ;
29/523 |
Current CPC
Class: |
B65D 41/08 20130101;
B65D 1/0246 20130101; Y10T 29/4987 20150115; Y10T 29/4994
20150115 |
Class at
Publication: |
220/634 ;
29/523 |
International
Class: |
B65D 025/24; B21D
039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 1998 |
FR |
98 02571 |
Claims
1. Process for manufacturing a metal can (1) equipped with a
threaded neck on which any type of removable head can be fitted,
comprising at least the following steps: a) production of a can
with a bottom and a cylindrical or shaped wall b) formation of a
neck (4) at the open end of the can c) use of a ring (5) equipped
with a spindle hole (52) and a thread (54) over its outer surface
(55), and sleeve fitting of said ring (5) by driving its spindle
hole (52) around the neck (4) formed in the previous step, and
characterized in that it also includes the following step: d)
plastic expansion of the said neck (4), the diameter of the outer
surface (42) of the neck (4) being expanded to exceed the value of
the inner diameter of the spindle hole (52) of the ring (5) when at
rest.
2. Manufacturing process for a metal can (1) equipped with a
threaded neck according to claim 1, characterized in that the said
plastic expansion of the neck (4) corresponds to an incremental
plastic deformation equal to at least 2% at the inner surface of
the neck.
3. Manufacturing process for a metal can (1) equipped with a
threaded neck according to claim 1, characterized in that the
shoulder (41) formed on the neck (4), designed to act as a stop
when ring (5) is fully sleeve fitted on the neck (4) formed in step
c).
4. Manufacturing process for a metal can (1) equipped with a
threaded neck according to claim 1, characterized in that a plastic
ring (5) is used.
5. Manufacturing process for a metal can (1) equipped with a
threaded neck according to claim 1, characterized in that a ring
(5) is used with a height such that after the said ring has been
sleeve fitted onto the neck (4), a part (48) of the said neck (4)
projects beyond the ring (5), and that the previous steps in the
process are followed by rolling the said portion (48) projecting
beyond the ring (5) in order to make a rolled edge (6).
6. Manufacturing process for a metal can (1) equipped with a
threaded neck according to claim 5, characterized in that it is
followed by a final step to smooth the rolled edge (6).
7. Receptacle with a metal can (1) equipped with a neck (4) and
designed to be fixed to any type of removable head, the said
removable head being provided with fastening means, characterized
in that it comprises a ring (5) equipped with fastening means (54)
complementary to the means on the head, the said ring bonding to
the neck (4) of the metal can (1) with a sufficiently strong force
to resist the removable head separation torque.
8. Receptacle with a metal can (1) equipped with a neck (4)
fastened by screwing with a removable head, characterized in that
the said receptacle is provided with locking means.
Description
TECHNICAL DOMAIN
[0001] This invention relates to a process for making cans made of
a low carbon steel or aluminum alloy, manufactured by deep drawing,
drawing and ironing or extrusion, in which the inner wall is
covered with a protective coating and which are equipped with a
threaded neck designed to fix any type of removable head, for
example aerosol spray distribution heads, of the eco-refill type,
but also for the attachment of a closing cap.
STATE OF ART
[0002] According to standard practice as described in GB 1 445 758,
cans with a bottom and a cylindrical wall are manufactured starting
from round and flat pieces made of low carbon steel or aluminum
alloy, and using deep drawing, drawing and ironing of blanks or
backward extrusion (impact extrusion) of slugs. Once formed, these
cans are usually varnished on their inner surface, and painted
and/or varnished on their outer surface. The open end of the can is
then formed to have a cylindrical neck with a smaller diameter, and
a strong plastic deformation is then applied by necking.
[0003] For practical reasons to facilitate application with a
roller or a spray gun, it is better to apply the paint or varnish
on the cylindrical surface before necking. The varnish on the inner
surface is necessary for many types of applications, in order to
prevent contact between the bare metal and the contents of the can.
The metallic surface must be well protected throughout the period
during which the can is being used and it is important that the
inner varnish covers this surface fully and continuously. Prior art
includes paints and varnish that remain undamaged during
necking.
[0004] Since the metal used (low carbon steel or aluminum alloy) is
an inexpensive and easy-to-recycle packaging material, it seemed a
good idea to develop receptacles onto which aerosol spray
distribution heads or covers could be screwed, as is the case for
glass and plastic bottles. For example, the receptacle could then
be sold full and a screwed cap could be fitted onto it. The user
screws and unscrews the distribution head, designed for multiple
use, according to his needs. The receptacle could then be refilled,
or the consumer could throw it away with the rest of his waste, and
it could be taken for recycling.
[0005] In order to obtain this type of metallic receptacle
satisfying the "eco-refill" principle, it must be possible to make
a thread, for example on the neck of the receptacle, in order to
participate in the attachment of any type of head. This thread must
not damage the varnish layer described above, that has been
subjected to necking in order to form the neck, and which must
maintain its protective properties in all cases.
[0006] In the past, the thread was usually made using internal
tooling with a helical impression, acting mainly as a support and
shaping mold, and an external tooling acting like one or several
rollers. The European patent application EP 0 510 291 (NUSSBAUM)
describes a process for making an improved thread, in which the
thread(s) is(are) shaped by means of an internal tooling and an
external tooling, both toolings being rotated in a coordinated
manner such that sliding takes place between the neck material and
each tooling. This prevents the neck metal from accumulating and
folding in front of the external threading tool and being pushed in
the direction of advance of the tooling.
[0007] The neck is then cut off on the same device, in other words
without having removed the receptacle, leaving a bare surface, in
other words unprotected and possibly with burrs, on the edge
surrounding the orifice.
Problem that Arises
[0008] Even if sliding occurs between the tooling and the neck
material, it is impossible to avoid further damage to the varnish.
Thus, micro-crazing is observed on the varnish at the thread, both
on the outer surface and the inner surface of the neck wall. This
crazing makes the can more sensitive to corrosion by the packaged
product.
[0009] Furthermore, with the can thus obtained, it is impossible to
position the distributing head precisely with respect to the edge
and the shoulder. It is difficult to control the position of the
heads, which has negative consequences both on the leak tightness
of the assembly and on its esthetic appearance.
Purpose of the Invention
[0010] The process according to the invention is a process for the
manufacture of a metallic can comprising at least the following
steps:
[0011] a) production of a can with a bottom and a cylindrical or
shaped wall, for example by deep drawing, drawing and ironing,
extrusion or extrusion-drawing, possibly followed by a painting or
varnishing deposit on at least the inner surface of the cylindrical
wall, followed by a varnish annealing treatment;
[0012] b) necking, in order to make a neck on the open end of the
can, this step possibly being followed by cutting open end of the
neck perpendicular to the center line of the can;
[0013] c) use of a ring with a spindle hole and threaded on its
outer surface, and sleeve fitting of the said ring so that its
spindle hole fits around the neck formed in the previous step, in
an operation that will subsequently be called "sleeve fitting":
[0014] and characterized in that it also includes the following
step:
[0015] d) plastic expansion of the said neck, the outside diameter
of the neck being expanded until it is larger than the inside
diameter of the spindle hole of the ring when unstressed.
[0016] The process is characterized by the use of a ring, for
example made of a plastic molded ring (but it could be made of any
other material--metallic, machined or die forged, etc.), with a
globally toroidal shape, with a cylindrical inner surface that we
will subsequently call the spindle hole, and an outer cylindrical
threaded surface. The diameter of the spindle hole is slightly
greater than the outside diameter of the neck that has just been
formed on the can, such that the ring can be sleeve fitted into
place freely.
[0017] The thread formed on the outer surface of the ring is
preferably a standard thread, for example with a
[0018] triangular or trapezoidal section, more suitable for precise
positioning of the distributor head with respect to the metallic
can. The thread obtained in prior art, in other words directly by
rolling on the neck, was rounded and consequently imprecise.
Furthermore, since rolling is no longer necessary to form the
thread, there is no additional damage to the varnish on the inner
surface of the neck of the can.
[0019] Finally, the choice of a plastic ring together with a
distribution head fitted with an attachment skirt also made of
plastic, improves the sealing conditions when the said distribution
head is put into position by screwing.
[0020] A first end of the ring is brought into position facing the
can neck that was obtained by necking during the previous step b)
and the said neck is then inserted inside the spindle hole in the
said ring. This is a relative movement; this sleeve fitting
operation may also be made by moving the ring and keeping the can
motionless. In this case, this step can be carried out in the same
way as the previous and next steps, during the same can clamping
phase, in other words these operations may be carried out on the
same machine, the cans being placed on a circular rotating table
for which the step by step rotation brings them in front of
different tools in sequence, each adapted to one of these steps,
and themselves installed on a circular tool holder plate. A device
of this type has already been described, for example in FR 1 434
177 (LECHNER).
[0021] Since precise positioning of the heads to be fixed on the
can is required, it is desirable to place the ring precisely on the
neck and to create a stop system that gives good positioning at the
end of sleeve fitting. The shape of the first end of the ring can
be designed so that it is recessed and matches the shoulder of the
can. It would also be possible, and preferable, to form a small
shoulder on the neck, at a certain distance from the edge of the
neck. This distance can be very precise when the shoulder is made
at the same time as the end of the neck is cut off (optionally) in
step b). The ring also has a surface that stops in contact with the
shoulder formed on the neck. For example, this surface may be
obtained by making a shoulder in the spindle hole. The shoulder
made on the neck must be sufficiently "high" (radial height) so
that it can act as a stop for the corresponding surface on the ring
while it is being put into position, in other words before
expansion of the neck.
[0022] The height of the neck above the spindle hole is controlled
by this stop system acting when the ring is fully sleeve fitted. It
is advantageous to include a subsequent step in which this part
projecting beyond the ring is rolled outwards, so that it traps it
and prevents any axial backwards movement. Therefore, the
projection distance is chosen such that a rolled edge can be made,
for example by stamping. It depends on the outside diameter of the
plastic ring and the inside diameter of the neck.
[0023] Once the ring has been sleeve fitted and is in contact with
the neck, the neck and the ring surrounding it are expanded, for
example by stamping, the neck being expanded in the range of
plastic deformations (in other words irreversible), the final
diameter after elastic recovery being slightly greater than the
diameter of the spindle hole of the ring at rest, in other words in
the initial state free of any mechanical stress.
[0024] The neck is preferably expanded over its entire length, so
as to obtain the largest possible contact surface between the neck
and the ring after expansion.
[0025] By carrying out this type of deformation and ensuring that
the elastic recovery effect of the spindle hole of the ring is
greater than the elastic recovery effect of the neck, which is easy
to ensure when the ring is made of a plastic material, a strong
bond is obtained between the ring and the neck over the entire
contact surface. The bond force between the ring and the neck
depends on the amount of the expansion and the magnitude of their
contact areas. The amount of the expansion is limited by the
ductility of the neck material. The contact surface, which depends
primarily on purely geometric conditions, is an easier parameter to
control.
[0026] Expansion consists of applying a plastic deformation by
expanding a metal that has already been strongly deformed during
shaping of the cylindrical can (deformation which is particularly
high close to the free edge of the can) and then strong necking.
Consequently, the metal is in a very work hardened state,
characterized by high mechanical properties but low residual
ductility.
[0027] The applicant was surprised to observe that this residual
ductility was actually greater than expected, due to the particular
deformation history imposed on the metal; necking followed by
circumferential expansion, the principal deformation axes remaining
parallel to the axial, radial and ortho-radial directions at all
times. However, although the metal is more ductile than expected,
it is desirable to allow for a sufficiently large gap between the
diameter of the ring hole and the initial diameter of the neck
formed in step b) to facilitate sleeve fitting of the ring over the
neck, but sufficiently small so that expansion will not cause
necking, or even rupture of the metal.
[0028] The limiting value that must not be exceeded depends on the
nature of the metal and the geometry of the can to be obtained, and
can be determined experimentally using simulation tests reproducing
the thermo-mechanical conditions of the various steps in the
shaping process considered, on the metal considered. Preferably,
expansion is carried out such that it results in an incremental
plastic deformation exceeding 2% on the inner surface of the neck.
The upper limit of this incremental plastic deformation varies as a
function of the ductility of the alloy chosen, for which the work
hardened state after necking is very favorable for good ductility
in circumferential expansion.
[0029] In our example applicable to a particular geometry of a can
made of a 1050 A alloy (inside diameter of the neck of the order of
15 mm), the clearance between the hole of the ring and the neck
remains approximately one tenth of a millimeter, and the inside
diameter of the neck after expansion is increased by about 0.3 mm,
corresponding to an incremental plastic deformation of about 2% at
the inner surface of the neck.
[0030] Therefore at the end of expansion, there is a strong bond
over the entire contact surface between the neck and the hole of
the ring. This bond can be quantified by measuring the untightening
torque necessary to separate the ring from the neck, that we will
subsequently call the sliding torque. In our example, it is found
that the sliding torque exceeds 20 Nm, in other words that it is
far greater than torques necessary to screw and unscrew the
removable head. Standard NF H 35103 for glass rings can be used to
estimate the order of magnitude of these tightening torques.
[0031] The process is advantageously followed by the following
steps:
[0032] e) rolling, for example by stamping, the end of the neck
[0033] f) smoothing, which consists of moving a roller bearing on
the edge of the neck formed by rolling in the previous step, and
designed to improve the surface condition of the varnish layer.
[0034] The edge is rolled preferably outwards, since in this case
the ring can be fixed in position axially, preventing any axial
backwards movement. However, the principal function of the rolled
edge is to improve the leak tightness of the assembly, since it
forms a rounded edge covered with varnish, in other words a
toroidal shape with a circular section which is much more suitable
to produce a leak tight joint than the as-cut edge, bare and flat
edge, on which burrs may be present, used in prior art.
Furthermore, this geometry prevents contact between the packaged
product and the metal edge that is not necessarily protected by
varnish.
[0035] There is no doubt that the varnished layer is damaged once
again during rolling, resulting in a disturbed surface condition on
which there are sharp edges and micro-cracks, fairly similar to
what is observed on threads obtained by rolling directly. The next
smoothing operation is designed to improve this surface condition,
by closing crazing and leveling of sharp edges.
[0036] These two additional operations can thus give particularly
satisfactory leak tightness of the can + head assembly.
[0037] If the ring is made of plastic, it is recommended that the
stress relaxation that inevitably takes place in this type of
material should be taken into account, and which has the
consequence of reducing the tightness a few hours after expansion.
Taking account of geometric manufacturing tolerances, this
loosening may be significant, in other words sufficient so that the
ring can no longer resist the head screw untightening torque, which
would trap it on the can without providing leak tightness. In this
situation, the can would then be unsuitable for use.
[0038] Longitudinal grooves can be made in the hole of the plastic
ring in order to prevent the unwanted effects of this loosening.
The applicant has observed that this type of relief on the surface
of the hole, which is easy to produce while the ring is being
molded, improves the long term tightness between the ring and the
neck, no doubt because it modifies the distribution and intensity
of stresses and therefore the effect of stress relaxation.
[0039] Additional operations can also be carried out on the neck
before sleeve fitting the ring; for example sanding, scratching,
deformation by rolling, machining, allowing at least one pin to
project during machining of the shoulder that acts as a ring
penetration stop. An inverse thread can also be made on the neck
and on the ring, to be sure that it is always possible to unscrew
the head even if the ring is completely loose.
[0040] Thus, it is possible to make a receptacle according to the
invention with a metal can fitted with the neck, designed to be
fixed to any type of removable head (of the eco-refill type), the
head being fitted with fastening means such as a thread, a rim or a
click fit groove, characterized in that it comprises a ring fitted
with additional fastening means other than those on the head, the
said ring bonding to the neck of the metallic can with a
sufficiently strong bond to resist the removable head separation
torque.
[0041] The distribution head is usually covered by a protective cap
that is fitted with a cylindrical skirt that extends close to the
shoulder of the can. For the purposes of this invention, this inner
end of the skirt and the lower end of the ring can be fitted with
means of preventing the receptacle from being opened, for example a
radial click fit locking system (vertical attachment), or notches
inside a breakable locking strip (plastic rings with unbreakable
notches and multi-notches).
[0042] Due to the presence of the ring used in this invention, it
is possible to have eco-refill type metal cans equipped with
reliable locking systems. The rolling means used in prior art
resulted in a rounded and imprecise thread, but could not be used
to make a sufficiently sharp relief capable of trapping a locking
strip. However, with the ring according to this invention, this
sharp relief is easy to form during molding, for example by
increasing the outside diameter at the first end of the ring.
[0043] This end thus acts as a mating ring, the edge of which can
trap a locking strip, for example connected to the inner end of a
cap skirt by several breakable bridges, like the ring described in
EP 0 107 680. This ring can also be fitted with ratchet teeth, and
the locking means described in FR 2 665 142 can be reproduced. This
latter system has the advantage that a large torque is not
necessary to separate the strip.
[0044] The process according to the invention will be better
understood after reading the detailed description of a particular
embodiment, presented as a non-limitative example.
EXAMPLE EMBODIMENT OF THE INVENTION
[0045] FIG. 1 shows a can with a threaded neck according to prior
art associated with the bottom part of a distribution head provided
with a hole in which a pump can be fitted in order to distribute
the product in the spray form.
[0046] FIG. 2 shows a can with a threaded neck designed for the
attachment of an aerosol distributor made according to the
invention.
[0047] FIG. 3 shows a diametric half-section of an enlarged view of
the neck and the ring obtained by the process according to the
invention, after the ring has been sleeve fitted, the neck has been
expanded and the free edge of the neck has been rolled. This same
figure shows the free end of the neck before rolling, in dashed
lines.
[0048] The can 1 illustrated in FIG. 2 is made of a 1050A aluminum
alloy. It is composed of a bottom 2 and a cylindrical wall 3 with
diameter 35 mm. Its free end has been formed into an approximately
cylindrical neck 4 with height and diameter equal to approximately
10 mm and 15 mm respectively. The ring 5 is made of polypropylene.
It is held fixed onto neck 4 by expansion of the neck made
according to the invention and by rolling the end 48 of the neck 4
leading to the formation of a rounded edge 6, in other words with a
circular toroidal shape, and always coated with varnish. The edge 6
forms the edge (rounded in this case) of the open end of the can
surrounding its orifice 7.
[0049] The ring 5, more easily seen on the half-section in FIG. 3,
is of molded polypropylene. Its shape is globally toroidal, with a
spindle hole 52 and an external cylindrical surface 55 on which a
thread 54 is formed. The diameter of the spindle hole 52 is
slightly greater than the outside diameter of the neck of the can
obtained by necking (average 0.1 mm, maximum 0.3 mm), such that the
ring may be sleeve fitted without applying force. The thread 54
formed on the outer surface 55 of the ring 5 is a standard thread
with a triangular section. The ring also has a shoulder 53 formed
in the spindle hole 52, the small ledge being designed to form a
stop on the shoulder 41 formed on the neck 4 of the can after the
ring 5 has been fully sleeve fitted on neck 4.
[0050] The process for making the can in this example comprises the
conventional steps for making an aluminum allow aerosol can:
[0051] slugs made of 1050 A aluminum alloy
[0052] tumbling of slugs in the presence of a lubricant such as
zinc stearate
[0053] impact extrusion of the slugs, possibly followed by one or
several drawing passes
[0054] trimming of the end
[0055] stripping, designed to eliminate traces of extrusion and
drawing lubricants
[0056] deposition of varnish by spraying on the inner surface,
followed by baking at about 200-265.degree. C. designed to dry and
polymerize the said varnish
[0057] deposition of a coat of lacquer with a roller, followed by
drying
[0058] the can decor is printed, usually by offset, and possibly
followed by an overprinting varnish and baking again
[0059] the cans are put into position on a circular table rotating
step by step, bringing each can in front of a different tool in
each step, the tools being adapted to the different phases
described below, these tools themselves being mounted on a circular
tool holder plate.
[0060] formation of the neck and cutting of the free edge. Necking
is done gradually by stamping in several passes with shaping dies,
the final die matching the required shape of the shoulder. While
cutting the free edge 49 of the neck 4, a small shoulder 41 is
formed on the neck at a precise distance from the top end 49 of the
neck 4.
[0061] sleeve fitting the ring A first end 51 of the ring 5 is put
into position facing neck 4 of can 1 which was obtained by necking
during the previous step, and ring 5 is then sleeve fitted on neck
4. When the shoulder 53 formed in the spindle hole 52 of the ring 5
stops in contact with the shoulder 41 on neck 4, the ring 5 is
retained in this position. This stop system acting after the ring
has been sleeve fitted, controls the height of the part 48 of neck
4 that projects from the spindle hole 52. In this case it is of the
order of 2 mm. The first end 51 of the ring is molded such that it
acts as a mating ring 56 on which a locking strip can be fixed.
[0062] Expansion Once the ring has been sleeve fitted and held in
contact with the ring, the neck 4 and the ring 5 are expanded by
stamping until the diameter of the outer surface 42 of the neck 4
is greater than the diameter of the spindle hole 52 of the ring 5
at rest, after elastic recovery. In this case expansion is done by
stamping, in other words using an internal tool that is inserted in
the orifice and then applying pressure to the free edge. The
conical and then cylindrical shape of the stamping tool imposes a
plastic expansion that increases the diameter of the outer surface
42 of the neck 4 by about 0.5 mm, over the entire length L of the
cylindrical part of the neck. This thus gives a strong bond over
the entire contact surface between the neck and the hole of the
ring. The spindle hole of the ring is marked with longitudinal
striations, which eliminates any risk of loosening due to stress
relaxation that occurs sometimes after expansion.
[0063] rolling and smoothing The end 48 of the neck 4 projecting
from the ring is then rolled by stamping. The rounded edge 6 thus
formed fixes the ring in position axially, and in particular forms
a rounded edge, always covered with varnish, improving the
tightness of screwed can + head assemblies. The next smoothing
operation, designed to improve the surface condition of the varnish
at the rounded rolled edge, consists of passing the roller over the
said rolled edge with a very low pressure, just sufficient to
smooth off rough edges created on the varnish and to close off
cavities created during the previous steps.
[0064] With this geometry (inside diameter of the neck of the order
of 15 mm), the ring according to the invention is rigidly fixed on
the bottle neck since it resists a sliding torque exceeding 20 Nm.
This value can then be compared with the range of values of
unscrewing torques to be applied to cap rings (between 2 and 8 Nm),
particularly in standard AFNOR NF H 35103 (glass rings and
caps).
Advantages of the Process According to the Invention
[0065] This process can be used to make eco-refill type cans.
[0066] The interchangeable head can easily be detached from the
can, so that each part used in the assembly can easily be recovered
and recycled.
[0067] The varnish is less damaged on the inner surface of the
neck, which makes the can less sensitive to corrosion by the
product contained in it.
[0068] The ring is positioned such that the distributor head is
fixed in leaktight manner and is in a precise and repeatable
position with a controlled clearance between the skirt and the
shoulder, favorable to improving the esthetic appearance of the
assembly.
[0069] For the first time, an eco-refill type metallic can can be
fitted with a distribution head protected by a locking strip.
* * * * *