U.S. patent application number 12/114416 was filed with the patent office on 2008-08-28 for deformation of thin walled bodies.
Invention is credited to Santiago Garcia Campo, Juan Saiz Goiria.
Application Number | 20080202182 12/114416 |
Document ID | / |
Family ID | 26243613 |
Filed Date | 2008-08-28 |
United States Patent
Application |
20080202182 |
Kind Code |
A1 |
Campo; Santiago Garcia ; et
al. |
August 28, 2008 |
Deformation of Thin Walled Bodies
Abstract
A thin walled body is deformed in a process in which the body is
gripped securely in a holding station and, whilst gripped in the
holding station, tooling engages to deform the peripheral wall of
the body at a predetermined wall zone. The tooling is provided at a
tooling station which is adjacent the holding station during
deformation. The predetermined wall zone is co-aligned with the
tooling by rotation of the body about an axis prior to securing at
the holding station.
Inventors: |
Campo; Santiago Garcia;
(Llodio (Alava), ES) ; Goiria; Juan Saiz; (Llodia
(Alava), ES) |
Correspondence
Address: |
GORDON & JACOBSON, P.C.
60 LONG RIDGE ROAD, SUITE 407
STAMFORD
CT
06902
US
|
Family ID: |
26243613 |
Appl. No.: |
12/114416 |
Filed: |
May 2, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11314630 |
Dec 21, 2005 |
7398665 |
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12114416 |
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10182643 |
Sep 30, 2002 |
7003999 |
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11314630 |
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Current U.S.
Class: |
72/14.9 ; 72/37;
72/379.4; 72/414; 72/421 |
Current CPC
Class: |
B21D 51/26 20130101;
B21D 51/2692 20130101; B21D 17/02 20130101; B44B 5/0004 20130101;
B21D 15/06 20130101; B21D 51/2646 20130101; Y10S 72/715 20130101;
B65D 1/165 20130101 |
Class at
Publication: |
72/14.9 ;
72/379.4; 72/414; 72/421; 72/37 |
International
Class: |
B21D 11/20 20060101
B21D011/20 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2000 |
GB |
0003033.8 |
Oct 27, 2000 |
GB |
0026325.1 |
Feb 9, 2001 |
GB |
PCT/GB01/00526 |
Claims
1. A method of deforming a thin walled body comprising: (i) holding
the body gripped securely in a holding station; and (ii) whilst
gripped in the holding station engaging tooling to deform the
peripheral wall of the body at a predetermined wall zone, the
tooling being provided at a tooling station which is adjacent the
holding station during deformation; wherein the predetermined wall
zone is co-aligned with the tooling by rotation of the body about
an axis prior to securing at the holding station.
2. A method according to claim 1, wherein: the body is gripped non
rotatably at the holding station.
3. A method according to claim 1, wherein: the tooling is provided
at a tooling station and said tooling station is advanced relative
to the holding station, such that an internal tooling part is
inserted into the interior of the body and an external tooling part
is positioned externally of the body whilst the body is gripped
securely at the holding station; and the tooling is operated to
engage with and deform the peripheral wall of the body at a
predetermined wall zone whilst the body is gripped in a fixed
orientation in the holding station; wherein the predetermined wall
zone is co-aligned with the tooling by rotation of the body about
an axis prior to securing at the holding station in said fixed
orientation for deforming of the wall of the body.
4. A method according to claim 1, wherein: the holding station
comprises a holding station of a multi-station holding table and
the deformation tooling is provided at a deformation tooling
station of a multi-station tooling table, the tooling table and
holding table being rotationally indexable relative to one another
to bring the bodies in succession to the deformation tooling.
5. A method according to claim 1, wherein: the body is optically
viewed to determine orientation of the body relative to a datum and
subsequently rotated about said axis to a datum orientation.
6. A method according to claim 5, wherein: with the body in the
datum orientation, the body is inserted into a clamp of the holding
station.
7. Apparatus for deforming a thin walled body comprising: i) a
holding station for holding the body gripped securely; ii) a
tooling station including tooling arranged to engage with and to
deform the body at a predetermined wall zone on the peripheral wall
whilst the body is gripped securely in the holding station, the
tooling station being positioned at a location adjacent the holding
station and advanced relative to the tooling station for
deformation of the body; iii) determination means for determining
the orientation of the cylindrical body relative to a reference
datum situation; and iv) means for co-ordinated movement to
reconfigure the body about an axis of the body to accord with the
datum situation prior to the body being gripped at the holding
station in a fixed orientation for deforming of the wall of the
body.
8. Apparatus according to claim 7, wherein: the holding station is
configured to grip the body non-rotatably.
9. Apparatus according to claim 7, wherein: the tooling comprises
an internal tooling part and an external tooling part arranged to
engage within the interior and exterior of the body
respectively.
10. Apparatus according to claim 7, further comprising: i) a
multi-station holding table, respective holding stations comprising
a respective clamp for clamping securely a respective body; and ii)
a multi-station tooling table being positioned adjacent the holding
table, the tooling table and holding table being rotationally
indexable relative to one another to bring the bodies in succession
to the tooling station for coordinated deformation, the tooling
table being advanceable relative to the holding table, a
coordinated deformation tooling station of the tooling table
including an internal tooling part and an external tooling part
arranged to engage within the interior, and on the exterior, of the
body respectively, together to deform the body at a predetermined
wall zone on the body with reference to a pre-applied design on the
wall of the body, whilst the body is clamped securely in the
holding station.
11. Apparatus according to claim 7, further comprising: optical
viewing means to determine the orientation of the body relative to
the datum situation.
12. Apparatus according to claim 7, further comprising: a necking
apparatus for performing a necking operation on the body.
13. Apparatus according to claim 10, wherein: the tooling table
includes a necking station to which the body is indexed.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 11/314,630, filed Dec. 21, 2005, which is a
continuation of U.S. application Ser. No. 10/182,643, filed Sep.
30, 2002, now U.S. Pat. No. 7,003,999, both of which are related to
PCT Application No. PCT/GB01/00526, filed Feb. 9, 2001, G.B.
Application No. 0003033.8, filed Feb. 10, 2000, and G.B.
Application No. 0026325.1, filed Oct. 27, 2000, all of which are
incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to deformation of generally
thin walled bodies, particularly thin walled containers or
tube-form bodies which may be of cylindrical or other form.
[0004] The invention is particularly suited to embossing of thin
walled metallic bodies (particularly aluminium containers) by
embossing or the like. More specifically the invention may be used
in processes such as registered embossing of thin walled bodies,
particularly registered embossing of containers having pre-applied
(pre-printed) surface decoration.
[0005] 2. State of the Art
[0006] It is known to be desirable to deform by embossing or the
like the external cylindrical walls of metallic containers such as
aluminium containers. In particular attempts have been made to
emboss the walls of containers at predetermined locations to
complement a printed design on the external surface of such a
container. In such techniques it is important to coordinate the
embossing tooling with the preprinted design on the container wall.
Prior art proposals disclose the use of a scanning system to
identify the position of the container relative to a datum position
and reorientation of the container to conform to the datum
position.
[0007] Prior art embossing techniques and apparatus are disclosed
in, for example, WO-A-9803280, WO-A-9803279, WO-A-9721505 and
WO-A-9515227. Commonly in such techniques the container is loaded
into an internal tool which acts to support the container and also
co-operate with an external tool in order to effect embossing. Such
systems have disadvantages, as will become apparent from the
following.
SUMMARY OF THE INVENTION
[0008] An improved technique has now been devised.
[0009] According to a first aspect, the present invention provides
a method of deforming a thin walled body, the method comprising:
[0010] i) holding the body gripped securely at a holding station;
[0011] ii) engaging tooling to deform the wall of the body at a
predetermined wall zone, the tooling being provided at a tooling
station which is adjacent the holding station during deformation;
[0012] wherein the predetermined wall zone is co-aligned with the
tooling by means of co-ordinated movement of the tooling prior to
deforming engagement with the wall of the body.
[0013] According to a further aspect, the invention provides
apparatus for deforming a thin walled body, the apparatus
including: [0014] i) a holding station for holding the body gripped
securely; [0015] ii) a tooling station including tooling to deform
the body at a predetermined wall zone of the body, the tooling
station being positioned at a location adjacent the holding station
during deformation; [0016] iii) determination means for determining
the orientation of the cylindrical body relative to a reference
(datum) situation; [0017] iv) means for coordinated movement to
reconfigure the tooling to co-align with the predetermined wall
zone prior to deforming engagement of the tooling with the body.
Co-alignment of the tooling and the wall zone of the body typically
required in order to ensure that embossing deformation accurately
lines up with pre-printed decoration on the body. In the technique
of the present invention, the body is not passed from being
supported at a holding station to being supported by the tooling
but, by contrast, remains supported at the holding station
throughout the deforming process.
[0018] Re-configuration of the tooling avoids the requirement for
the or each holding or clamping station to have the facility to
re-orientate a respective body.
[0019] The technique is particularly suited to embossing containers
having wall thicknesses (t) in the range 0.25 mm to 0.8 mm
(particularly in the range 0.35 mm to 0.6 mm). The technique is
applicable to containers of aluminium including alloys, steel,
tinplate steel, internally polymer laminated or lacquered metallic
containers, or containers of other materials. Typically the
containers will be cylindrical and the deformed embossed zone will
be coordinated with a pre-printed/pre-applied design on the
circumferential walls. Typical diameters of containers with which
the invention is concerned will be in the range 35 mm to 74 mm
although containers of diameters outside this range are also
susceptible to the invention.
[0020] Beneficially the tooling will be re-configurable by rotation
of the tooling about a rotational tooling axis to co-align with the
predetermined wall zone.
[0021] The determination means preferably dictates the operation of
the tooling rotation means to move/rotate the tooling to the datum
position. The determination means preferably determines a shortest
rotational path (clockwise or anti-clockwise) to the datum position
and triggers rotation of the tooling in the appropriate sense.
[0022] The length of time available to perform the steps of
re-orientation and deformation is relatively short for typical
production runs which may process bodies at speeds of up to 200
containers per minute. Re-orientation of the tooling (particularly
by rotation of the tooling about an axis) enables the desired
re-orientation to be achieved in the limited time available. The
facility to re-orientate clockwise or anti-clockwise following
sensing of the container orientation and shortest route to the
datum position is particularly advantageous in achieving the
process duration times required.
[0023] According to a further aspect, the invention provides
apparatus for use in deforming a wall zone of a thin walled
container, the apparatus comprising internal tooling to be
positioned internally of the container, and external tooling to be
positioned externally of the container, the external and internal
tooling co-operating in a forming operation to deform the wall zone
of the container, the internal tooling being moveable toward and
away from the centreline or axis of the container between a
retraction/insertion tooling configuration in which the internal
tool can be inserted or retracted from the interior of the
container, to a wall engaging configuration for effecting deforming
of the wall zone.
[0024] Correspondingly a further aspect of the invention provides a
method of deforming a thin walled container, the method comprising:
[0025] inserting internal tooling into the interior of the
container, the internal tooling being in a first, insertion
configuration for insertion; [0026] moving the tooling to a second,
(preferably expanded) position or configuration closely adjacent or
engaging the internal container wall so as to facilitate
deformation of a wall zone of the container; [0027] returning the
tooling from the second position toward the first tooling
configuration thereby to permit retraction of the internal tooling
from the container. Because the internal tooling is movable toward
and away from the container wall (preferably toward and away from
the axis/centreline of the container), embossed relief features of
greater depth/height can be produced. This is because prior art
techniques generally use an internal tool which also serves to hold
the container during deformation (embossing) and therefore
typically only slight clearance between the internal tool diameter
and the internal diameter of the container has been the standard
practice.
[0028] In accordance with the broadest aspect of the invention, the
relief pattern for embossing may be carried on cam portions of
internal and/or external tools, the eccentric rotation causing the
cam portions to matingly emboss the relevant portion of the
container wall.
[0029] A particular benefit of the present invention is that it
enables a greater area of the container wall (greater dimension in
the circumferential direction) to be embossed than is possible with
prior art techniques where the emboss design would need to be
present on a smaller area of the tool. Rotating/cam-form tooling,
for example, has the disadvantage of having only a small potential
area for design embossing.
[0030] Re-configurable, particularly collapsible/expandable
internal tooling provides that greater depth/height embossing
formations can be provided, the internal tooling being collapsed
from engagement with the embossed zone and subsequently retracted
axially from the interior of the container.
[0031] Embossed feature depth/height dimensions in the range 0.5 mm
and above (even 0.6 mm to 1.2 mm and above) are possible which have
not been achievable with prior art techniques.
[0032] According to a further aspect, the invention provides
apparatus for use in deforming the cylindrical wall of a thin
walled cylindrical container, the apparatus comprising an internal
tooling part to be positioned internally of the container, and an
external tooling part to be positioned externally of the container,
the external and internal tools co-operating in a forming operation
to deform a portion of the cylindrical container wall therebetween;
wherein tooling actuation means is provided such that: [0033] (a)
the external and internal tools are movable independently of one
another to deform the container wall; and/or [0034] (b) deforming
force applied to the external and internal tools is positioned at
force action zones spaced at opposed sides of the zone of the
container wall to be deformed.
[0035] As described above, the technique of the invention is
particularly suited to embossing containers having relatively thick
wall thickness dimensions (for example in the range 0.35 mm to 0.8
mm). Such thick walled cans are suitable for containing pressurised
aerosol consumable products stored at relatively high pressures.
Prior art techniques have not been found to be suitable to
successfully emboss such thicker containers, nor to produce the
aesthetically pleasing larger dimensioned emboss features as is
capable with the present invention (typically in the range 0.3 mm
to 1.2 mm depth/height).
[0036] The technique has also made it possible to emboss containers
(such as seamless monobloc aluminium containers) provided with
protective/anti-corrosive internal coatings or layers without
damage to the internal coating or layer.
[0037] According to a further aspect, the invention therefore
provides an embossed container or tube-form product, the product
comprising a product side-wall having a thickness substantially in
the range 0.25 mm to 0.8 mm and a registered embossed wall zone,
the embossed deformation having an emboss form depth/height
dimension substantially in the range 0.3 mm to 1.2 mm or above.
[0038] Preferred features of the invention are defined in the
appended claims and readily apparent from the following
description. The various features identified and defined as
separate aspects herein are also mutually beneficial and may be
beneficially included in combination with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The invention will now be further described in a specific
embodiment, by way of example only, and with reference to the
accompanying drawings, in which:
[0040] FIG. 1 is a flow diagram of a process according to the
invention;
[0041] FIG. 2 is a view of a container to be operated upon in
accordance with the invention;
[0042] FIG. 3 is a side view of the container of FIG. 2 in a finish
formed state;
[0043] FIG. 4 is a 360 degree view of a positional code in
accordance with the invention;
[0044] FIG. 5 is a schematic side view of apparatus in accordance
with the invention;
[0045] FIGS. 6 and 7 are half plan views of apparatus components of
FIG. 5;
[0046] FIGS. 8, 9 and 10 correspond to the views of FIGS. 5, 6 and
7 with components in a different operational orientation;
[0047] FIG. 11 is a schematic close up sectional view of the
apparatus of the preceding figures in a first stage of the forming
process;
[0048] FIG. 11a is a detail view of the forming tools and the
container wall in the stage of operation of FIG. 11;
[0049] FIGS. 12, 12a to 16,16a correspond to the views of FIGS. 11
and 11a; and
[0050] FIG. 17 is a schematic sectional view of an embossed zone of
a container wall in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0051] Referring to the drawings the apparatus and technique is
directed to plastically deforming (embossing or debossing) the
circumferential wall of an aluminium container 1 at a predetermined
position relative to a preprinted decorative design on the external
container wall. Where the embossing deformation is intended to
coincide with the printed decorative design, this is referred to in
the art as Registered Embossing.
[0052] In the embodiment shown in the drawings, a design 50
comprising a series of three axially spaced arc grooves is to be
embossed at 180 degree opposed locations on the container wall (see
FIG. 16a). For aesthetic reasons it is important that the location
at which the design 50 is embossed is coordinated with the printed
design on the container 1 wall. Coordination of the container 1
axial orientation with the tooling to effect deformation is
therefore crucial.
[0053] Referring to FIGS. 5 to 7 the forming apparatus 2 comprises
a vertically orientated rotary table 3 operated to rotate (about a
horizontal axis) in an indexed fashion to successively rotationally
advanced locations. Spaced around the periphery of table 3 are a
series of container holding stations comprising clamping chucks 4.
Containers are delivered in sequence to the table in random axial
orientations, each being received in a respective chuck 4, securely
clamped about the container base 5.
[0054] A vertically orientated forming table 6 faces the rotary
table 3 and carries a series of deformation tools at spaced tooling
stations 7. Following successive rotary index movements of rotary
table 3, table 6 is advanced from a retracted position (FIG. 5) to
an advanced position (FIG. 8). In moving to the advanced position
the respective tools at tooling stations 7 perform forming
operations on the container circumferential walls proximate their
respective open ends 8. Successive tooling stations 7 perform
successive degrees of deformation in the process. This process is
well known and used in the prior art and is frequently known as
necking. Necked designs of various neck/shoulder profiles such as
that shown in FIG. 3 can be produced.
[0055] Necking apparatus typically operates at speeds of up to 200
containers per minute giving a typical working time duration at
each forming station in the order of 0.3 seconds. In this time, it
is required that the tooling table 6 moves axially to the advanced
position, the tooling at a respective station contacts a respective
container and deforms one stage in the necking process, and the
tooling table 6 is retracted.
[0056] In accordance with the invention, in addition to the
necking/shoulder-forming tooling at stations 7, the tooling table
carries embossing tooling 10 at an embossing station 9. The
embossing tooling (shown most clearly in FIGS. 11 to 16) comprises
inner forming tool parts 11a, 11b of respective arms 11 of an
expandable internal tool mandrel 15. Tool parts 11a, 11b carry
respective female embossing formations 12.
[0057] The embossing tooling 10 also includes a respective outer
tool arrangement including respective arms 13 carrying tooling
parts 13a, 13b having complementary male embossing formations 14.
In moving to the table 7 advanced position the respective internal
tool parts 11a, 11b are positioned internally of the container
spaced adjacently the container 1 wall; the respective external
tool parts 13a,13b are positioned externally of the container
spaced adjacently the container 1 wall.
[0058] The internal mandrel 15 is expandable to move the tooling
parts 11a, 11b to a relatively spaced apart position in which they
abut the internal wall of the container 1 (see FIG. 12) from the
collapsed position shown in FIG. 11 (tools 11a, 11b spaced from the
internal wall of the container 1). An elongate actuator rod 16 is
movable in a longitudinal direction to effect expansion and
contraction of the mandrel 15 and consequent movement apart and
toward one another of the tool parts 11a,11b. A the cam head
portion 17 of the actuator rod 16 effects expansion of the mandrel
15 as the actuator rod 16 moves in the direction of arrow A. The
cam head portion 17 acts against sloping wedge surfaces 65 of the
tool parts 11a, 11b to cause expansion (moving apart) of the tool
parts 11a, 11b. The resilience of arms 11 biases the mandrel 15 to
the closed position as the rod 16 moves in the direction of arrow
B.
[0059] Outer tool arms 13 are movable toward and away from one
another under the influence of closing cam arms 20 of actuator 21
acting on a cam shoulder 13c of respective arms 13. Movement of
actuator 21 in the direction of arrow D causes the external tooling
parts 13a to be drawn toward one another. Movement of actuator 21
in the direction of arrow E causes the external tool parts 13a to
relatively separate. Arms 13 and 11 of the outer tool arrangement
and the inner mandrel are retained by cam support ring 22. The arms
11, 13 resiliently flex relative to the support ring 22 as the
actuators 21, 16 operate.
[0060] As an alternative to the cam/wedge actuation arrangement,
other actuators may be used such as hydraulic/pneumatic,
electromagnetic (e.g. solenoid actuators) electrical
(servo/stepping) motors.
[0061] The operation of the embossing tooling is such that the
internal mandrel 15 is operable to expand and contract
independently of the operation of the external tool parts 13a.
[0062] The internal mandrel 15 (comprising arms 11) and the
external tooling (comprising arms 13) connected at cam support ring
22, are rotatable relative to table 6, in unison about the axis of
mandrel 15. Bearings 25 are provided for this purpose. A
servo-motor (or stepping motor) 26 is connected via appropriate
gearing to effect controlled rotation of the tooling 10 relative to
table 6 in a manner that will be explained in detail later.
[0063] With the tooling 10 in the position shown in FIG. 11, the
mandrel 15 is expanded by moving actuator rod 16 in the direction
of arrow A causing the internal tooling parts 11a to lie against
the internal circumferential wall of cylinder 1, adopting the
configuration shown in FIGS. 12, 12a. Next actuator 21 moves in the
direction of arrow D causing cam arms 20 to act on cam shoulder 13c
and flexing arms 13 toward one another. In so doing the external
tooling parts 13a engage the cylindrical wall of container 1,
projections 14 deforming the material of the container 1 wall into
respective complementary receiving formations 12 on the internal
tooling parts 11a.
[0064] The deforming tooling parts 11a, 13a, can be hard, tool
steel components or formed of other materials. In certain
embodiments one or other of the tooling parts may comprise a
conformable material such as plastics, polymeric material or the
like.
[0065] An important feature is that the internal tooling parts 11a
support the non deforming parts of the container wall during
deformation to form the embossed pattern 50. At this stage in the
procedure, the situation is as shown in FIGS. 13, 13a. The
configuration and arrangement of the cam arms 20, cam shoulders 13c
of the external embossing tooling and the sloping (or wedge) cam
surface of internal tooling parts 11a (cooperating with the cam
head 17 of rod 16) provide that the embossing force characteristics
of the arrangement can be controlled to ensure even embossing over
the entire area of the embossed pattern 50. The external cam force
action on the outer tool parts 13a is rearward of the embossing
formations 14; the internal cam force action on the inner tool
parts 11a is forward of the embossing formations 12. The forces
balance out to provide a final embossed pattern of consistent depth
formations over the entire zone of the embossed pattern 50.
[0066] Next actuator 21 returns to its start position (arrow E)
permitting the arms 13 of the external tooling to flex outwardly to
their normal position. In so doing tooling parts 13a disengage from
embossing engagement with the container 1 external surface. At this
stage in the procedure, the situation is as shown in FIGS. 14,
14a.
[0067] The next stage in the procedure is for the internal mandrel
to collapse moving tooling parts 11a out of abutment with the
internal wall of the cylinder 1. At this stage in the procedure,
the situation is as shown in FIGS. 15, 15a.
[0068] Finally the tooling table 6 is retracted away from the
rotatable table 3 withdrawing the tooling 10 from the container. At
this stage in the procedure, the situation is as shown in FIGS. 16,
16a.
[0069] In the embodiment described, the movement of the tools to
effect embossing is translational only. It is however feasible to
utilise rotational external/internal embossing tooling as is known
generally in the prior art.
[0070] The rotary table is then indexed rotationally moving the
embossed container to adjacent with the next tooling station 7, and
bringing a fresh container into alignment with the embossing
tooling 10 at station 9.
[0071] The embossing stages described correspond to stages 106 to
112 in the flow diagram of FIG. 1.
[0072] Prior to the approachment of the embossing tooling 10 to a
container 1 clamped at table 3 (FIG. 11 and stage 106 of FIG. 1) it
is important that the container 1 and tooling 10 are accurately
rotationally oriented to ensure that the embossed pattern 50 is
accurately positioned with respect to the printed design on the
exterior of the container.
[0073] According to the present invention this is conveniently
achieved by reviewing the position of a respective container 1
whilst already securely clamped in a chuck 4 of the rotary table 3,
and rotationally reorientating the embossing tooling 10 to the
required position. This technique is particularly convenient and
advantageous because a rotational drive of one arrangement (the
embossing tooling 10) only is required. Chucks 4 can be fixed
relative to the table 3 and receive containers in random axial
rotational orientations. Moving parts for the apparatus are
therefore minimised in number, and reliability of the apparatus is
optimised.
[0074] The open ends 8 of undeformed containers 1 approaching the
apparatus 2 have margins 30 printed with a coded marking band 31
comprising a series of spaced code blocks or strings 32 (shown most
clearly in FIG. 4). Each code block/string 32 comprises a column of
six data point zones coloured dark or light according to a
predetermined sequence.
[0075] With the container 1 clamped in random orientation in a
respective chuck 4 a charge coupled device (CCD) camera 60 views a
portion of the code in its field of view. The data corresponding to
the viewed code is compared with the data stored in a memory (of
controller 70) for the coded band and the position of the can
relative to a datum position is ascertained. The degree of
rotational realignment required for the embossing tooling 10 to
conform to the datum for the respective container is stored in the
memory of main apparatus controller 70. When the respective
container 10 is indexed to face the embossing tooling 10 the
controller instigates rotational repositioning of the tooling 10 to
ensure that embossing occurs at the correct zone on the
circumferential surface of the container 1. The controller 70 when
assessing the angular position of the tooling relative to the
angular position to be embossed on the container utilises a
decision making routine to decide whether clockwise or
counterclockwise rotation of the tooling 10 provides the shortest
route to the datum position, and initiates the required sense of
rotation of servo-motor 26 accordingly. This is an important
feature of the system in enabling rotation of the tooling to be
effected in a short enough time-frame to be accommodated within the
indexing interval of the rotating table 3.
[0076] The coding block 32 system is in effect a binary code and
provides that the CCD camera device can accurately and clearly read
the code and determine the position of the container relative to
the tooling 10 datum by viewing a small proportion of the code only
(for example two adjacent blocks 32 can have a large number of
unique coded configurations). The coding blocks 32 are made up of
vertical data point strings (perpendicular to the direction of
extent of the coding band 31) in each of which there are dark and
light data point zones (squares). Each vertical block 32 contains
six data point zones. This arrangement has benefits over a
conventional bar code arrangement, particularly in an industrial
environment where there may be variation in light intensity,
mechanical vibrations and like.
[0077] As can be seen in FIG. 4, because the tooling 10 in the
exemplary embodiment is arranged to emboss the same pattern at 180
degree spacing, the coding band 31 includes a coding block pattern
that repeats over 180 degree spans.
[0078] The position determination system and control of rotation of
the tooling 10 are represented in blocks 102 to 105 of the flow
diagram of FIG. 1.
[0079] The coding band 31 can be conveniently printed
contemporaneously with the printing of the design on the exterior
of the container. Forming of the neck to produce, for example a
valve seat 39 (FIG. 3) obscures the coding band from view in the
finished product.
[0080] As an alternative to the optical, panoramic visual sensing
of the coding band 31, a less preferred technique could be to use
an alternative visual mark, or a physical mark (e.g. a deformation
in the container wall) to be physically sensed.
[0081] Referring to FIG. 17, the technique is particularly switched
to forming aesthetically pleasing embossed formations 50 of a
greater height/depth dimension (d) (typically in the range 0.3 mm
to 1.2 mm) than has been possible with prior art techniques.
Additionally, this is possible with containers of greater wall
thickness (t) than have been successfully embossed in the past.
Prior art techniques have been successful in embossing aluminium
material containers of wall thickness 0.075 mm to 0.15 mm. The
present technique is capable of embossing aluminium containers of
wall thickness above 0.15 mm, for example even in the range 0.25 mm
to 0.8 mm. The technique is therefore capable of producing embossed
containers for pressurised aerosol dispensed consumer products
which has not been possible with prior art techniques. Embossed
monobloc seamless aluminium material containers are particularly
preferred for such pressurised aerosol dispensed products
(typically having a delicate internal anti-corrosive coating or
layer protecting the container material from the consumer product).
The present invention enables such containers to be embossed
(particularly registered embossed).
[0082] As an alternative to the technique described above in which
the embossing tooling is rotated to conform to the datum situation,
immediately prior to the container being placed in the chuck 4 and
secured, the position of the container may be optically viewed to
determine its orientation relative to the datum situation. If the
orientation of the container 1 differs from the desired datum
pre-set situation programmed into the system, then the container is
rotated automatically about its longitudinal axis to bring the
container 1 into the pre-set datum position. With the container in
the required datum position, the container is inserted
automatically into the clamp 4 of the holding station, and clamped
securely. In this way the relative circumferential position of the
printed design on the container wall, and the position of the
tooling is coordinated. There is, thereafter, no requirement to
adjust the relative position of the container and tooling. This
technique is however less preferred than the technique primarily
described herein in which the embossing tooling 10 is
re-orientated.
[0083] The invention has primarily been described with respect to
embossing aluminium containers of relatively thin wall thicknesses
(typically substantially in the range 0.25 mm to 0.8 mm. It will
however be readily apparent to those skilled in the art that the
essence of the invention will be applicable to embossing thin
walled containers/bodies of other material such as steel, steel
tinplate, lacquered plasticised metallic container materials an
other non-ferrous or non-metallic materials.
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