't IA
`D'
`Igl a
`(DAS)
`
`_
`S
`66655 el‘Vlce
`
`WIPO
`
`WORLD
`INTELLECTUAL PROPERTY
`ORGANIZATION
`
`CERTIFICATE OF AVAILABILITY OF A CERTIFIED PATENT DOCUMENT IN A
`
`DIGITAL LIBRARY
`
`The International Bureau certifies that a copy of the patent application indicated
`below has been available to the WIPO Digital Access Service since the date of
`availability indicated, and that the patent application has been available to the
`indicated Office(s) as of the date specified following the relevant Office code:
`
`Document details:
`
`Country/Office: G B
`
`Filing date: 28 Jul 2016 (28.07.2016)
`
`Application number: 16130619
`
`Date of availability of document:
`
`08 Sep 2016 (08.09.2016)
`
`The following Offices can retrieve this document by using the access code:
`
`JP, US, SE, NZ, KR, GB, AU, ES, IB, EE, CN, MA, Fl
`
`Date of issue of this certificate:
`
`22 Jun 2017 (22.06.2017)
`
`34, ohemin des Colombettes
`
`
`
`

`

`Concept House
`Cardiff Road
`
`Newport
`South Wales
`
`NPlO 8QQ
`
`Certified Office Copy
`
`1, the undersigned, being an officer duly authorised in accordance with Section 74(1) and (4) of
`the Deregulation & Contracting Out Act 1994, to sign and issue certificates on behalf of the
`Comptroller—General, hereby certify that annexed hereto is a true copy of the documents as
`originally filed in connection with patent application GBl6l306l .9 on 28 July 2016 and as
`stored electronically on the Patents Electronic Case file System.
`
`The Patents Electronic Case—file System is compliant with British Standard BS10008 —
`Evidential weight and legal admissibility of information stored electronically and 1S015801 -
`Electronic imaging — information stored electronically, recommendations for trustworthiness and
`reliability.
`
`In accordance with the Patents (Companies Re-registration) Rules 1982, if a company named in
`this certificate and any accompanying documents has re-registered under the Companies Act
`1980 with the same name as that with which it was registered immediately before re-registration
`save for the substitution as, or inclusion as, the last part of the name of the words "public limited
`company" or their equivalents in Welsh, references to the name of the company in this certificate
`and any accompanying documents shall be treated as references to the name with which it is so
`re—registered.
`
`In accordance with the rules, the words "public limited company” may be replaced by p.l.c., plc,
`P.L.C. or PLC.
`
`Re-registration under the Companies Act does not constitute a new legal entity but merely
`subjects the company to certain additional company law rules.
`
`Signed A HAYES
`
`Dated 2 August 2016
`
`

`

`
`
` .fi,
`intellectual
`
`Property
`OffiCe
`
`Patents Form 1
`Patents Act 1977 (Rule 12)
`
`Request for grant of a patent
`
`.
`.
`Application number
`1. Your reference
`
`GB 1613061 _9
`
`2.
`
`Full name, address and postcode of the applicant or of
`each applicant
`
`1200203669
`1016017671 D01063
`28/07/2016 230.00 DepositAccount
`
`Concept House
`Cardiff Road
`Newport
`South Wales
`NP10 SQQ
`
`RL/PX215464GB
`
`CROWN PACKAGING TECHNOLOGY, INC.
`11535 South Central Avenue
`Alsip 60803-2599
`Illinois
`United States of America
`
`Patents ADP number (if you know it)
`
`3. Title of the invention
`RADIAL OFFSET MONITOR
`
`MARKS & CLERK LLP
`4. Name of your agent (ifyou have one)
`“Address for service" to which all correspondence should MARKS & CLERK LLP
`be sent. This may be in the European Economic area or
`Fletcher House (2nd Floor)
`Channel Islands (see warning note below)
`Heatley Road Oxford Science Park
`(including the postcode)
`Oxford OX4 4GE
`Oxfordshire
`
`United Kingdom
`
`Patents ADP number (if you know it)
`
`5. Priority declaration: Are you claiming priority from one or
`more earlier-filed patent applications? If so, please give
`details ofthe application(s)
`
`Country
`
`Application number
`
`Date of filing
`
`PDAS Access Code
`
`6. Divisionals etc: Is this application a divisional application,
`or being made following resolution of an entitlement
`dispute about an earlier application. If so, please give the
`application number and filing date ofthe earlier
`application
`
`7.
`
`lnventorship: (Inventors must be individuals not
`companies)
`
`Are all the applicants named above also inventors?
`
`8. Are you paying the application fee with this form?
`
`No
`
`Yes
`
`Number of earlier UK
`app'mat'on
`
`Date of filing
`(day/month Wear)
`
`(REV DEC07)
`Intellectual Property Office is an operating name ofthe Patent Office
`
`Patents Form 1(e)
`https://www.gov.uk/ipo
`
`

`

`Patents Form 1
`
`9. Accompanying documents: please enterthe number of
`pages of each item accompanying this form.
`
`Continuation sheets of this form
`
`Description:
`
`1 3
`
`Claim(s):
`
`Abstract:
`
`2
`
`1
`
`Drawing(s):
`
`14
`
`If you are n_ot filing a description, please give details of
`the previous application you are going to rely upon
`
`
`
`Application number Date of filingCountry PDAS Access Code
`
`
`
`
`
`10. If you are also filing any of the following, state how many
`against each item.
`
`Priority documents:
`
`0
`
`Statement of inventorship and right to grant of a patent
`(Patents Form 7):
`
`Request for search (Patents Form 9A):
`
`Request for a substantive examination (Patents Form 10):
`
`1
`
`1
`
`1
`
`Pre-conversion Archive
`Any other documents (please specify):
`
`PDAS Registration Form
`
`11. WVe request the grant of a patent on the basis of this application.
`
`Signature: Subject: Robert Lind 364; Issuer: European Date:
`Patent Office, European Patent Office CA
`GZ
`
`28 Jul 2016
`
`12. Name, e-mail address, telephone, fax and/or mobile
`number, if any, of a contact point for the applicant
`
`LIND, Dr Robert
`Email: oxford@marks-clerk.com
`Telephone: +44(0)1865 397900
`Fax: +44(0)1865 397919
`
`Warning
`After an application for a patent has been filed, the Comptroller will consider whether publication or communication of the
`invention should be prohibited or restricted under section 22 of the Patents Act 1977. You will be informed if it is necessary to
`prohibit or restrict your invention in this way. Furthermore, if you are resident in the United Kingdom and your application contains
`information which relates to military technology, or would be prejudicial to national security orthe safety of the public, section 23 of
`the Patents Act 1977 prohibits you from applying for a patent abroad without first getting written permission from the Office unless
`an application has been filed at least 6 weeks beforehand in the United Kingdom for a patent for the same invention and either no
`direction prohibiting publication or communication has been given, or any such direction has been revoked. Until such time or until
`the revocation of any direction, for any such application the address for service referred to at part 4 above must be in the United
`Kingdom.
`
`Although you may have an address for service in the Channel Islands, any agent instructed to act for you must reside or have a
`place of business in the European Economic Area or Isle of Man.
`
`(REV DECO7)
`
`Patents Form 1(e)
`
`

`

`M&C PX215464GB
`
`Technical Field
`
`RADIAL OFFSET MONITOR
`
`The present invention relates to a radial offset monitor, and in particular, though not
`
`necessarily, to a can bodymaker comprising a radial offset monitor. The invention also
`
`relates to a method of detecting a radial offset of a bodymaker ram and/or punch.
`
`1O
`
`Background
`
`15
`
`20
`
`25
`
`30
`
`In known bodymakers for the production of thin-walled metal can bodies by a “drawing
`
`and wall—ironing” (DWI) process, metal cups are fed to the bodymaker and carried by a
`
`punch on the end of a ram through a series of dies to produce a can body of the
`
`desired size and thickness. The series of dies may include a redraw die for reducing
`
`the diameter of the cup and lengthening its sidewall, and one or more ironing dies for
`
`wall-ironing the cup into a can body. The area or cradle of the bodymaker frame within
`
`which the dies are located is known as the “toolpack”. The can body carried on the
`
`punch may ultimately contact a bottom forming tool or “domer” so as to form a shape
`
`such as a dome on the base of the can. An exemplary bodymaker is described in
`W09934942.
`
`When setting up a can bodymaker, the ram and its drive components are typically fixed
`
`in place on the bodymaker frame. This aligns the axis of the ram with the main axis of
`
`the bodymaker. The other components, including for example the redraw and ironing
`
`dies and domer, are then aligned with the ram.
`
`Over time, frictional forces and general wear will cause the alignment of the ram to vary
`
`slightly.
`
`In addition, a high speed reciprocating ram is generally subject to at least
`
`some vibration, due to the impact of the ram on the can body and to the variable
`
`“droop” of the ram as it moves from and to its fully-extended position. When the ram
`
`carries the can body into contact with the domer, any misalignment can lead to the can
`
`body end splitting, particularly where the can body is aluminium.
`
`If the misalignment is
`
`slight, the split (sometimes known as a “smile”) may not be immediately visible to the
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`2
`
`naked eye, and the split may lead to the can bursting once the can body has been
`
`filled. This may not occur until the filled can has been purchased.
`
`Alignment procedures for known bodymakers are complex and require significant skill
`
`to ensure that the machines can be operated safely and efficiently. A typical method of
`
`aligning the ram of a bodymaker comprises halting the production line and inserting two
`
`gauge rings comprising sensors into the bodymaker toolpack, preferably in
`
`the
`
`positions usually occupied by the first and third ironing dies. The gauges must be
`
`inserted in the correct orientation and must then be calibrated. Measurements may
`
`then be taken as the punch passes through the gauge ring on the forward stroke,
`
`backward stroke and during and after doming. This process is carried out
`
`in the
`
`absence of a can body to avoid the sensors detecting the can body rather than the
`
`punch.
`
`Alignment and re-alignment of known bodymakers is
`
`therefore a time consuming
`
`process which requires the can body production line to be halted. The high volume
`
`nature of the can industry means that
`
`lost production time can be very costly for
`
`producers.
`
`Summary of the Invention
`
`According to a first aspect there is provided a radial offset monitor comprising a body
`
`defining an internal bore and one or more eddy current sensors spaced around the
`
`bore. The bore may be cylindrical.
`
`The radial offset monitor may be configured to detect the misalignment of an object
`
`moving axially through the bore, relative to the axis, i.e. to detect offset along a radius.
`
`The radial offset monitor may be configured to be attached to a toolpack module of a
`
`can bodymaker, wherein said object is a ram and/or a punch, or a can body held on the
`
`punch.
`
`The radial offset monitor may comprise comprising four eddy current sensors
`
`equiangularly spaced around the bore.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`The eddy current sensors may be adjustable in a direction orthogonal to the axis.
`
`3
`
`According to a second aspect there is provided a can bodymaker comprising the radial
`
`offset monitor of the first aspect, wherein the object is a ram and/or a punch, or a can
`
`body held on the punch, of the can bodymaker.
`
`The body of the radial offset monitor may be co-located with, or integrated into, a
`
`stripper housing.
`
`The can bodymaker may comprise a controller having an input for receiving sensor
`
`data from the radial offset monitor; and a processor configured to compute one or more
`
`of ram position, ram trajectory, punch position, punch trajectory, can body presence,
`
`can body sidewall thickness.
`
`The can bodymaker may comprise an adjustment mechanism to automatically adjust
`
`one or more components of the bodymaker in response to detection by the radial offset
`
`monitor of a misalignment of the ram and/or punch and/or can body.
`
`The one or more components may be or may include the ram, the punch, a domer, and
`
`the adjustment may be an axial adjustment.
`
`According to a third aspect there is provided a can bodymaker toolpack comprising the
`
`radial offset monitor of the first aspect.
`
`According to a fourth aspect there is provided a method of detecting axial misalignment
`
`of an object subject to reciprocating motion along an axis,
`
`the method comprising
`
`obtaining electrical output signals from one or more eddy current sensors spaced
`
`around a bore extending through a body within which the sensor(s) is(are) located, as
`
`the object moves through the bore; and processing the signal(s) to detect any axial
`
`10
`
`15
`
`20
`
`25
`
`30
`
`misalignment.
`
`The method may be employed in a can bodymaker, wherein said object may be a ram
`
`and/or a punch, or a can body held on the punch, of the can bodymaker.
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`4
`
`The method may comprise the radial offset monitor being co—located with, or integrated
`
`into, a stripper of the can bodymaker.
`
`The method may comprise processing the sensor data to compute one or more of ram
`
`position, ram trajectory, punch position, punch trajectory, can body presence, can body
`sidewall thickness.
`
`The method may comprise using an adjustment mechanism to automatically adjust one
`
`or more components of the bodymaker in order to correct the misalignment.
`
`The method may be carried out while the bodymaker is producing can bodies.
`
`Brief Description of the Drawings
`
`Figure 1 illustrates schematically a cross-section of a part of a known bodymaker;
`
`Figure 2a is a perspective view of a plurality of sensors integrated into a stripper
`
`housing;
`
`Figure 2b is a cross-sectional schematic view of a sensor within the stripper housing;
`
`Figure 3 is a cross-sectional view of the stripper housing of Figure 2 in position on a
`
`10
`
`15
`
`20
`
`bodymaker;
`
`Figure 4 is an enlarged cross—sectional view of the bodymaker of Figure 3;
`
`Figure 5a is a perspective cross-sectional view of the bodymaker of Figure 3;
`
`Figure 5b is an enlarged section of the view of Figure 5a;
`
`Figure 6a is a perspective view of a stripper housing comprising adjustable sensors
`
`and attached to a plastic stripper;
`
`Figure 6b is a perspective view of the stripper housing of Figure 6a in position on a
`
`bodymaker;
`
`Figure 7a is a perspective view of a stripper housing comprising adjustable sensors
`
`and attached to a steel stripper;
`
`Figure 7b is a cross-sectional view of the stripper housing of Figure 7a in position on a
`
`25
`
`30
`
`bodymaker;
`
`Figure 8 is a cross-sectional view of the stripper housing of Figure 7a;
`
`Figure 9 is a perspective view of a plurality of sensors integrated into a sensor housing;
`
`Figure 10 is a cross-sectional view of the sensor housing of Figure 9 in position on a
`
`35
`
`bodymaker;
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`5
`
`Figure 11a is a perspective cross—sectional view of the bodymaker of Figure 10;
`
`Figure 11b is an enlarged section of the view of Figure 11a;
`
`Figure 12 is a graphical representation of sensor output;
`
`Figure 13 is an alternative graphical representation of sensor output; and
`
`Figure 14 is a further alternative graphical representation of sensor output.
`
`Detailed Description
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`Figure 1
`
`illustrates schematically a cross-section of a known long-stroke bodymaker 1.
`
`The bodymaker 1 comprises a frame 2 and a ram 4 supported by a pair of hydrostatic
`
`bearings (not shown). The ram 4 is constructed using a metal or metal alloy and
`
`moves horizontally through a series of ironing dies 5. The dies 5 are clamped to a
`
`large block of metal or bolster plate 9. On the forward stroke, the ram 4 moves towards
`
`a bottom forming tool or domer 6 and on the return stroke the ram 4 moves away from
`
`the domer 6. A punch 7 is mounted on the end of the ram 4 nearest the domer 6. The
`
`punch 7 is constructed using a metal or metal alloy, such as steel. At the furthest
`
`extent of the ram’s 4 fonNard stroke, a base of a can body (not shown) held on the end
`
`of the punch 7 is brought into contact with the domer 6. At the furthest extent of the
`
`ram’s 4 backward stroke, the punch 7 will be located at a position to the right of a
`
`blankholder 3 of the bodymaker 1.
`
`In one complete cycle the ram 4 therefore moves
`
`from the blankholder 3 to the domer 6 and back again.
`
`Metal cups are fed into the bodymaker 1 one at a time to the left of the blankholder 3
`
`position. Each cup is carried by the punch 7 through the series of dies 5 as described
`
`above, as the ram 4 moves forwards. At the end of the forward stroke the resulting can
`
`body is brought into contact with the domer 6 and the base of the can body is formed.
`
`As the ram 4 begins its return stroke, the can body is removed from the punch 7 by a
`
`stripper 8. The stripper 8 may comprise a plastic or a steel ring. The stripper 8 in this
`
`example consists of stripping fingers (not shown here) mounted within an annular
`
`plastic stripper housing 13,
`
`located at one end of the die assembly 5. The radially
`
`inward ends of the stripping fingers extend into the bore of the die assembly 5 through
`
`which the punch 7 passes. On the forward stroke of the ram 4 the can body carried on
`
`the punch 7 deflects the stripping fingers as it moves along the bore of the die
`
`assembly 5. As the punch 7 moves on the return stroke, i.e. away from the domer 6,
`
`the stripping fingers prevent the can body from returning with the punch 7 and the can
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`6
`
`body is stripped from the punch 7 and then removed from the bodymaker 1.
`
`In other
`
`embodiments not shown here, the can body may be removed from the bodymaker 1 by
`
`pressurised air (alternatively, pressurised air may be used to assist removal by a
`
`stripper).
`
`Figures 2, 3, 4 and 5 illustrate a first embodiment of a radial offset monitor or ram
`
`position sensor 10 comprising a plurality of sensors 11 housed within the outer
`
`circumference of a stripper housing 13, which takes the form of an annular ring.
`
`In
`
`Figure 2a, the stripper housing 13 is illustrated from the rear,
`
`i.e. as seen from the
`
`toolpack of the bodymaker, and without the stripper being present.
`
`In this example,
`
`there are four sensors 11 equally spaced around the stripper housing 13, although
`
`fewer, or additional sensors, may be used. The housing 13 may be a monolithic block
`
`machined from a single piece of metal, and comprises an internal bore configured to
`
`accommodate a can body of specific diameter, located on the punch 7.
`
`The sensors
`
`11
`
`are eddy current sensors,
`
`such as the eddyNCDTTM range
`
`manufactured by Micro-EpsilonT'V'.
`
`Unlike simple inductive sensors, eddy current
`
`sensors provide the ability to measure distances to conductive objects with an
`
`extremely high degree of precision (in the nanometre range). Advantageously, no
`
`contact with the object is required, such that measurement is wear-free.
`
`The eddy current sensors 11 each comprise a coil (not shown here) inside an outer
`
`casing. The coil
`
`is supplied with a high-frequency alternating current
`
`in order to
`
`produce an electromagnetic field.
`
`The coil’s electromagnetic field induces eddy
`
`currents in the conductive object. These eddy currents create an opposing magnetic
`
`field which resists the field produced by the coil. The interaction of magnetic fields
`
`produced by the coil and the conductive object depends upon the distance between
`
`them, and changes when the distance changes. The sensors 11 then produce a
`
`10
`
`15
`
`20
`
`25
`
`30
`
`voltage output proportional to the change in distance between the conductive object
`and the sensor 11.
`
`The electromagnetic field produced by a sensor 11 is capable of penetrating non-
`
`metallic objects. This means that eddy current sensors 11 can be used to produce
`
`measurements even where the (metallic) object has a non-conductive coating, such as
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`7
`
`plastic, or where the metallic object is contaminated with dirt or oil. The sensors 11 are
`
`also substantially insensitive to temperature change.
`
`Each sensor 11 comprises a face 11a which is located within a circumference of the
`
`internal bore of the stripper housing 13 and which faces into the internal bore of the
`
`stripper housing 13. As illustrated in Figure 2b, each sensor 11 is housed within the
`
`stripper housing 13 such that the face 11a of the sensor 11 does not protrude from the
`
`stripper housing 13. The face 11a may be flush with an exterior of the housing 13, or
`
`the face 11a may be slightly recessed, as shown in Figure 2b. An air gap 16 is
`
`provided around the sensor face 11a, such that the sensor face 11a does not come
`
`into contact with the stripper housing 13. This avoids any interference from the stripper
`
`housing 13, which may be constructed from plastic or from metal.
`
`Figures 3, 4 and 5 illustrate the stripper housing 13 and integrated sensors 11 of Figure
`
`2 positioned within a bodymaker, such as the bodymaker of Figure 1.
`
`In these
`
`illustrated examples, a section of the bodymaker comprising the stripper 8, stripper
`
`housing 13, sensors 11 and bolster plate 9 is shown. This illustrated section of the
`
`bodymaker further comprises an adapter plate 14 and a retaining ring 15. The adaptor
`
`plate 14 enables the stripper 8 and stripper housing 13 to be attached to the
`
`bodymaker 1 and the retaining ring 15 holds the stripper 8 in place on the front of the
`
`stripper housing 13.
`
`In this illustrated example, the toolpack,
`
`identified by reference
`
`numeral 18, is shown without tools (i.e. the die assembly is not shown).
`
`An advantage of integrating the sensors 11 into an interior of the stripper housing 13 is
`
`that no additional space is required between the adapter plate 14 and the retaining ring
`
`15. Both the sensors 11 and stripper housing 13 may be accommodated within the
`
`space usually occupied by the stripper housing 13 alone, hence the overall longitudinal
`
`dimensions of the bodymaker 1 are unaffected by the inclusion of the sensors 11.
`
`Figure 4 illustrates the ram 4 on its forward stroke, passing through the internal bore of
`
`the stripper housing 13. Also illustrated is the can body unloader pocket 17, which
`
`forms part of the discharge turret and which transports the manufactured can body (not
`
`shown) away from the bodymaker.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`8
`
`The eddy current sensors 11 continuously sense or monitor the position or radial offset
`
`of the ram 4 (i.e. measure the distance between themselves and the ram surface) as it
`
`passes through the stripper housing 13 and send this information to a bodymaker
`
`controller (not shown), comprising a PLC (programmable logic circuit). The sensors 11
`
`and the controller may be in wired or
`
`in wireless communication. The controller
`
`calculates the distance of the ram 4 from a longitudinal bodymaker axis, indicated in
`
`Figure 4 by line AA. The alignment of the ram may also be measured with respect to a
`
`vertical bodymaker axis indicated in Figure 4 by line BB. The information provided by
`
`the sensors is displayed on an external device (not shown here) comprising a display
`
`screen, as will be further discussed below.
`
`It will be appreciated that a bodymaker may need to be re—configured to produce can
`
`bodies of different diameters, by replacing the toolpack with a toolpack having dies of a
`
`different diameter and by replacing the ram with a ram having a different diameter. For
`
`example, to accommodate a larger can body, a ram having a 2 inch diameter might be
`
`replaced by a ram having a 3 inch diameter.
`
`In this case, the stripper will also need to
`
`be replaced in order to accommodate the ram and to remove the can body.
`
`Figures 6, 7 and 8 illustrate a second embodiment of radial offset monitor 20,
`
`in which
`
`the eddy current sensors 11 integrated into a stripper housing 113 are adjustable.
`
`Figures 6a and 6b illustrate a plastic stripper 8a attached to the stripper housing 113 by
`
`a retaining ring 15. Figures 7a, 7b and 8 illustrate the same stripper housing 113, to
`
`which a steel stripper comprising steel fingers 8b is attached using the retaining ring
`
`15. The plastic stripper 8a has a smaller internal bore than the steel stripper 8b, hence
`
`the steel stripper 8b can accommodate a ram, and a can body, of larger diameter. The
`
`stripper housing 113 has an internal bore configured to accommodate the largest
`
`diameter ram to be used with the bodymaker.
`
`In order to facilitate the exchange of
`
`strippers 8a, 8b, each stripper 8a, 8b is provided with a stripper adapter ring 19a, 19b.
`
`When changing from one type of stripper to another, only the stripper 8a, 8b and the
`
`stripper adapter ring 19a, 19b need be replaced.
`
`In both Figures 6 and 7, eddy current sensors 11 which are configured to be adjustable
`
`are integrated into the stripper housing 113, as will be discussed in more detail below.
`
`In these examples,
`
`four eddy current sensors 11 are equally spaced around the
`
`stripper housing 113, with sensor faces 11a facing into the bore of the stripper housing
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`9
`
`113. An air gap (not shown here) is provided around each sensor face 11a, such that
`
`the sensor face 11a does not come into contact with the stripper housing 113.
`
`Figure 8 is a perspective cross-sectional view of the stripper housing 113 of Figure 7,
`
`shown attached to an adaptor plate 14. The steel stripper 8b is held in place on the
`
`stripper housing 113 by a retaining ring 15 and is provided with a stripper adapter ring
`
`19b. Although a steel stripper 8b is shown in this example, the plastic stripper 8a, or
`
`an alternative stripper, could also be used.
`
`The stripper housing 113 is configured to accommodate four adjustment mechanisms,
`
`one adjacent to each eddy current sensor 11. For example, the stripper housing 113
`
`may comprise cut outs of a suitable size and shape.
`
`In this example, each adjustment
`
`mechanism comprises a miniature high precision ball screw 21 and a guide mechanism
`
`22. The ball screw 21 converts rotary motion to linear motion.
`
`Each screw 21
`
`comprises a moveable collar 24 attached to the guide mechanism 22, which is in turn
`
`attached to the adjacent eddy current sensor 11 .
`
`Upon manual or automatic adjustment of
`
`the ball screw 21,
`
`the collar 24, guide
`
`mechanism 22 and hence the eddy current sensor 11 can be adjusted in a direction
`
`orthogonal to the inner face of the stripper housing 113.
`
`In other words, the eddy
`
`current sensor 11 can be adjusted, or screwed in or out, so that the face of the sensor
`
`11a either protrudes from, is flush with or is recessed into the inner face of the stripper
`
`housing 113.
`
`It will be appreciated that the position of the sensor face 11a can be
`
`adjusted depending upon the diameter of the ram which is to be used.
`
`Sensor
`
`recalibration may be required after adjustment.
`
`The adjustability of the sensors 11 allows the same stripper housing 113 to be used
`
`with a range of ram sizes. The ball screws 21 can be adjusted without removing the
`
`stripper housing 113 and so the sensors 11 can be easily and quickly configured to be
`
`used with a variety of ram sizes.
`
`A third embodiment of a radial offset monitor or ram position sensing gauge 30 is
`
`illustrated in Figures 9, 10 and 11.
`
`In this embodiment, a number of eddy current
`
`sensors 11 are housed in a separate sensor housing 12.
`
`In this illustrated example,
`
`there are four eddy current sensors 11 equally spaced around the annular sensor
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`10
`
`housing 12. The housing 12 comprises an internal bore configured to accommodate a
`
`can body located on the punch 7.
`
`In use, the sensor housing 12 is located between a stripper housing 213 and the
`
`stripper 8, as will be discussed further below. The face 11a of each sensor 11 is
`
`located within a circumference of an internal bore of the sensor housing 12, such that
`
`the face 11a of the sensor 11 does not protrude from the sensor housing 12. As
`
`discussed with reference to Figure 2b above, each sensor face 11a is surrounded with
`
`an air gap to avoid any interference from the sensor housing 12.
`
`Figures 10 and 11 illustrate the sensor housing 12 of Figure 9 in position within a
`
`bodymaker, such as the bodymaker of Figure 1, shown with the toolpack removed.
`
`In
`
`this illustrated example, the sensors 11 are not integrated into the stripper housing 213,
`
`but are instead mounted equiangularly around a separate sensor housing 12, located
`
`behind the stripper 8, Le. between the stripper 8 and stripper housing 213.
`
`In this case,
`
`the stripper housing 213 is adapted with one or more recesses to provide space for the
`
`sensor housing 12.
`
`The embodiments described above may be retrofitted to existing bodymakers.
`
`Advantageously, the embodiment of Figures 9, 10 and 11, in which a separate sensor
`
`housing 12 is provided, can be moved from one bodymaker to another in order to carry
`
`out diagnostic testing on the alignment of the ram 4.
`
`In other words, the sensor
`
`housing 12 may be removed from its position between the stripper 8 and the stripper
`
`housing 213 without affecting the configuration or the operation of the bodymaker.
`
`Similarly, the sensor housing 12 may be re-fitted into the bodymaker where further
`
`diagnostic testing is
`
`required.
`
`The number of
`
`radial offset monitors required is
`
`therefore reduced.
`
`The eddy current sensors 11 provide precise, real-time information as to the ram 4
`
`position with respect to the bodymaker 1 axis or axes. Since the punch 7 is located on
`
`a distal end of the ram 4, the sensors 11 can also provide information regarding the
`
`position of the punch 7. Positional information can be provided by the sensors 11 both
`
`when the ram 4 is stationary and when the bodymaker 1
`
`is running,
`
`i.e. when the
`
`bodymaker is in normal operation and can bodies are being fed in. Since the radial
`
`offset monitor 10, 20, 30 either comprises a stripper housing 13, 113 or is mounted
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`between the stripper housing 213 and the stripper 8,
`
`it is not necessary to remove any
`
`of the dies 5.
`
`11
`
`In addition to dynamically monitoring the radial offset of the ram 4 with respect to an
`
`axis of the bodymaker, the sensors 11 can also provide information regarding the ram’s
`
`4 trajectory i.e. the path the ram 4 will take after it passes through the stripper housing
`
`13, 113, 213 and/or the sensor housing 12. This can be provided by taking a series of
`
`measurements of the ram’s position as it passes by the sensors 11.
`
`The sensor data received can also be used to monitor the punch 7 trajectory and
`
`alignment, as well as measuring ram 4 vibration. The use of highly sensitive eddy
`
`current sensors 11 also means that
`
`it
`
`is possible to detect whether a can body is
`
`present on the punch 7 or not, and to measure a thickness of the can body. Since the
`
`sensitivity of the eddy current sensors eliminates interference from the can body, these
`
`measurements can be taken while the bodymaker
`
`1
`
`is
`
`idle and also when the
`
`bodymaker 1 is making can bodies.
`
`Detection of the presence and/or thickness of a can body on the punch 7 is useful as it
`
`can indicate whether a can body has been properly removed from the punch 7 by the
`
`stripper 8, and whether there are any defects in the can body, e.g. the sidewall of the
`
`can body is too thin or too thick, potentially indicating cracks or splits.
`
`The signal
`
`from the sensors 11
`
`is sent
`
`to the bodymaker controller where it
`
`is
`
`converted and presented on a human-machine interface (HMI), which may comprise a
`
`screen or digital display. The signal can be presented in several different ways. For
`
`example, the processed signal output may show the position of the punch 7 in relation
`
`to its fully-aligned target position; the position of the ram/punch in relation to the A
`
`and/or B axis of the bodymaker; the trajectory of the ram/punch as a 3D plot; a 3D
`
`ram/punch patch plot or A-B axis ram/punch patch plot; a plot of the position of the ram
`
`or punch in relation to an axis of the bodymaker 1.
`
`Figure 12 is a graphical representation of an exemplary signal output from the sensors
`
`11 of any of the embodiments of Figures 2 to 11, showing the position of a ram
`
`operating at 100 cycles per minute (equivalent to the drive shaft operating at a speed of
`
`100 rpm). The signal output
`
`is recorded over a single cycle of the ram i.e. one
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`33594726—1-SBRADLEY
`
`

`

`M&C PX215464GB
`
`12
`
`complete ram stroke. The graph indicates the real—time radial deviation of the ram from
`
`its target or fully aligned position in millimetres. A deviation of 0.00 mm indicates that
`
`the ram is fully aligned and in its target position.
`
`The graph also illustrates any deviation of
`
`the ram from its target
`
`trajectory.
`
`A
`
`deviation of 0 degrees indicates th