Ink fountain and ink station assembly

Abstract

An ink fountain (206, Fig.2) for transferring ink to a roller (204, Fig.2) of an ink station assembly (200, Fig.2) of a can decorator (100, Fig.1). The ink fountain comprises a removable ink reservoir

Description

22 07 25 TECHNICAL FIELD 5 The present application relates to can decorators i.e., machines for transferring ink on to an outer surface of a can, such as a beverage or food can. BACKGROUND 10 Metal cans such as steel and aluminium beverage cans are commonly manufactured in two pieces. A first piece comprises a generally cylindrical container body with integral base, formed from a circular metal disc using a drawing and ironing process. A second piece comprises an end having a tab or ring-pull formed therein. The can is filled, e.g. with beverage, and the end subsequently fixed to the body to close the can using a 15 seaming process. A can decorator is used to print artwork (i.e. decoration) onto the external surface of the can body prior to filling of the can body and seaming of the end. The can decorator is typically operated to print an artwork on a number of can bodies, after which the can 20 decorator must be reconfigured to print a new artwork. During such changeovers, the can decorator needs to be cleaned thoroughly to remove ink left over from the previous production run, which would otherwise contaminate the ink that is to be used to print the new artwork. Ink reservoirs of the can decorator also need to be replenished, before another production run can commence. 25 Typically, the can decorator is cleaned manually between runs by a trained operator, which can lead to significant lost production time, which is particularly problematic given the very high production rates used in the can manufacturing industry and the inability of other downstream parts of the manufacturing process to continue to operate without a 30 constant supply of decorated can bodies. There are also health and safety concerns as the operators must access the can decorator while it is operating (e.g. to spray solvent onto and wipe down ink covered surfaces) in order to ensure that all the parts of the can decorator that come into contact with ink are clean. It is also desirable to reduce the amount of solvent used during the cleaning and / or the exposure of the operators to the 22 07 25 solvent(s). Excess ink is also typically not recovered after a production run ends, which can be inefficient and wasteful. WO2023102358 describes using a robotic arm to transfer ink to and from a can 5 decorator. SUMMARY The present invention seeks to address or at least alleviate the above problems. 10 According to a first aspect of the present disclosure there is provided an ink fountain for transferring ink to a roller of an ink station assembly of a can decorator. The ink fountain comprises a removable ink reservoir having an opening through which to transfer ink to an outer surface of the roller when the ink reservoir is installed into the ink fountain. The 15 ink reservoir comprises a barrier operable to selectively open or close the opening when the ink reservoir is installed into the ink fountain. Closing the opening of the ink reservoir with the barrier means that ink is prevented from leaving the ink reservoir through the opening. As the ink used for decorating cans is 20 typically quite viscous, the barrier may not need to form a tight seal over the opening, e.g., the ink may be retained in the ink reservoir even if there are small gaps between the barrier and the periphery of the opening. The barrier can be moved between open and closed configurations, e.g. by a sliding, rotational or hinged movement of the barrier with respect to the ink reservoir. In some implementations, the barrier may partially or 25 wholly form a sidewall of the ink reservoir when the opening is closed. With the barrier in a closed configuration, the ink reservoir can be filled with ink prior to the ink reservoir being installed into the ink fountain, and the barrier then moved to an open configuration to allow ink to transfer to the outer surface of the roller through the 30 opening. That is, a pre-filled ink reservoir can be installed into the ink fountain, thereby reducing the time needed to replenish or replace the ink in the ink fountain, e.g. during a changeover of can body design. By moving the barrier to the closed configuration whilst the ink reservoir is still installed 35 in the ink fountain, excess ink remaining in the ink reservoir can be retained when the 22 07 25 ink reservoir is removed from the ink fountain, e.g. for re-filling or replacement with another ink reservoir with the same or a different ink. Conventionally, unused ink remaining in the ink reservoir would be removed manually, e.g. by scraping away most of the ink and then washing the ink reservoir with a solvent, which is time consuming and 5 potentially hazardous for operators (particularly when the roller is still operating), and can require larger quantities of solvent to be used. The roller may, for example, have cells provided on its outer surface that, in use, receive the ink from ink fountain and help control the amount of ink that is transferred from the 10 roller to subsequent rollers in the ink station assembly. Such a roller may be referred to as an “anilox” roller in some cases. The ink fountain further comprises one or more nozzles for supplying cleaning fluid (e.g. a solvent, such as ethanol) to the outer surface of the roller when the ink reservoir is not 15 installed into the ink fountain. The nozzles may, for example, be configured such that cleaning fluid is sprayed onto the outer surface of the roller and / or onto regions of the ink fountain where ink tends to collect. Where multiple nozzles are used, they may be spaced apart in a direction parallel to an axis of the roller to ensure that the cleaning fluid has an even distribution on the outer surface of the roller. In general, the one or more 20 nozzles are connectable to a supply of cleaning fluid that is operable to force the cleaning fluid through the one or more nozzles. A control system may be provided to control supply of the cleaning fluid to the outer surface of the roller. For example, the control system may be configurable to cause cleaning fluid to be supplied through the one or more nozzles in response to a received electrical signal, e.g., the control system may be 25 computer controlled, such as via a wired or wireless connection. The control system may be configured to dispense a predetermined amount of cleaning fluid in response to the received electrical signal, such that excessive use of cleaning fluid can be avoided. Alternatively, the amount of cleaning fluid dispensed may be controlled by an operator or automatically, e.g. based on an amount of ink remaining in the ink fountain and / or ink 30 station assembly, which may be measured by a sensor, such as a colorimeter, configured to measure the amount of ink in the waste solvent. The cleaning fluid may be forced through the nozzles using compressed air in some implementations. 22 07 25 The one or more nozzles can be covered by the ink reservoir when the ink reservoir is installed into the ink fountain. That is, the ink reservoir may impede the supply of the cleaning fluid to the outer surface of the roller whilst the ink reservoir is in place. Such an arrangement may avoid the one or more nozzles (and any associated connections to a 5 cleaning fluid supply) from taking up space that can otherwise be given to the ink reservoir and prevent the nozzles from becoming blocked with ink. It may also act as a “fail-safe” against accidental discharge of cleaning fluid onto the roller. The ink reservoir can comprise an angled surface for directing ink towards the outer 10 surface of the roller, i.e. such that the ink flows towards the roller. The ink reservoir may then have a corresponding angled surface for supporting the angled surface of the ink reservoir. The one or more nozzles can be provided in the angled surface of the ink reservoir, thereby allowing the one or more nozzles to be directed towards the outer surface of the roller. 15 The ink fountain may additionally comprise one or more drainage holes through which to expel fluid from the ink fountain when the ink reservoir is not installed into the ink fountain. The drainage holes may create a (preferred) pathway along which ink and cleaning fluid can leave the ink fountain, thereby allowing large quantities of cleaning fluid to be 20 supplied to outer surface the roller in a short amount of time without flooding the ink fountain, which can reduce the amount of production time lost to cleaning. The ink and cleaning fluid may be directed into a drip tray located beneath the ink fountain. The drip tray can be removed such that the ink and cleaning fluid can be recovered for re-use or safe disposal. 25 The ink reservoir may comprise one or more locator pins (i.e. members that extend from an outer surface of the ink reservoir) corresponding to the one or more drainage holes for aligning the ink reservoir within the ink fountain (e.g. each locator pin may be received by a corresponding drainage hole). Thus, the locator pin(s) and drainage hole(s) may 30 ensure that the ink reservoir is installed into the ink fountain correctly prior to the opening of the ink reservoir being opened. In some implementations, the opening of the ink reservoir extends circumferentially with respect to the outer surface of the roller. That is, the opening may be defined by a 35 sidewall of the ink reservoir that extends partially around the (e.g. cylindrical) outer 22 07 25 surface of the roller. The barrier may also be movable circumferentially with respect to the outer surface of the roller to open and close the opening. Such configurations may help minimise the footprint of the ink fountain within the ink station assembly, while still ensuring that an appropriate amount of ink can be delivered to the roller. 5 In some implementations, the ink fountain (e.g. the ink reservoir of the ink fountain) may comprise a mechanism for locking the barrier in an open configuration when the ink reservoir is installed into the ink fountain. For example, the ink reservoir may comprise a handle for moving the barrier between the open configuration and a closed configuration, 10 and the handle may be operable to lock the barrier in the open configuration when the ink reservoir is installed into the ink fountain. For example, the handle may be rotatable away from the ink reservoir to allow the ink reservoir to be removed from or installed into the ink fountain using the handle, or moved into contact with part of the ink reservoir to lock the barrier in place. 15 The size of the opening when the barrier is locked in the open configuration may be chosen such that an appropriate flow of ink through the opening is obtained when the ink fountain is in use. That is, the mechanism for locking the barrier in the open configuration may ensure that the size of the opening is neither too small, such that the 20 flow ink to the roller is insufficient, nor too large, such that too much ink is transferred to the roller. In some cases, the mechanism may allow the barrier to be locked in one of multiple open configurations that have different sizes of opening to transfer ink to the outer surface of the roller at different rates. 25 In some implementations, the ink fountain comprises a scraper blade having an edge for removing ink from the outer surface of the roller. The scraper blade is preferably movable between a retracted configuration in which the edge of the scraper blade is spaced apart from the outer surface of the roller and an engaged configuration in which the edge of the scraper blade contacts the outer surface of the roller for removing ink therefrom. The 30 ink fountain may comprise an actuator, such as a pneumatic or hydraulic actuator, for moving the scraper blade between the retracted and engaged configurations. The actuator is preferably computer controlled. The ink fountain may additionally comprise a doctor blade that is spaced apart from the 35 outer surface of the roller (by a small amount) to ensure that ink coated onto the outer 22 07 25 surface of the roller has an appropriate and uniform thickness. The scraper blade may be operated independently of the doctor blade, e.g. no adjustment of the doctor blade may be necessary when the scraper blade is moved between the retracted and engaged configurations. 5 The ink fountain may comprise one or more nozzles arranged to direct fluid on to the scraper blade and / or the roller when the blade is in the engaged configuration. The one or more nozzles may be the same as or different from one or more nozzles that, if present, may be used to direct fluid onto the outer surface of the roller. The nozzles may, 10 for example, be provided between the scraper blade and the doctor blade (if present), e.g., to clean parts of the ink fountain that are not cleaned by the other one or more nozzles (if present). In the engaged configuration, the scraper blade can also guide used solvent and / or ink into the drip tray (when present). Thus, in some cases, the scraper blade can be moved into the engaged configuration (e.g. automatically, by the control 15 system), prior to the one or more nozzles directing fluid onto the roller and / or surrounding areas. Thus, the scraper blade can be used to help minimise transfer of solvent and / or residual ink to other parts of the ink station assembly or can decorator. According to a second aspect of the present disclosure there is provided a method of 20 configuring an ink station assembly of a can decorator. The ink station assembly comprises one or more rollers, including a first roller, operable to transfer ink to a printing plate. The method comprises transferring ink from an ink reservoir onto an outer surface of the first roller through an opening in the ink reservoir. The method further comprises closing the opening and removing the ink reservoir from the ink station assembly. The 25 ink reservoir may therefore be cleaned away from the ink station assembly and / or excess (i.e. leftover) ink remaining in the ink reservoir can be recovered. In some implementations, the method may comprise installing another ink reservoir into the ink station assembly in place of the ink reservoir, or adding ink to the ink reservoir 30 and re-installing the ink reservoir into the ink station assembly. The other ink reservoir may, for example, comprise ink or it may be clean and empty, such that it can be filled with ink whilst installed into the ink fountain. The method may also comprise, before transferring ink from the ink reservoir on to the 35 outer surface of the first roller of the ink station assembly through the opening in the ink 22 07 25 reservoir, creating an opening in the ink reservoir, e.g. by moving a barrier to create the opening. The ink reservoir can therefore be filled before the ink reservoir is installed into the ink fountain. 5 The method may also comprise cleaning the outer surface of the first roller after the ink reservoir has been removed from the ink station assembly. For example, cleaning the outer surface of the roller may comprise directing cleaning fluid (e.g. a solvent) onto the first roller and / or scraping ink from the outer surface of the first roller, e.g. using one or more nozzles and / or a scraper blade as described above for the first aspect. 10 According to a third aspect of the present disclosure there is provided an ink fountain for transferring ink to a roller of an ink station assembly of a can decorator. The ink fountain comprises an ink reservoir having an opening through which to transfer ink to an outer surface of the roller. The ink fountain further comprises one or more nozzles for supplying 15 cleaning fluid to the outer surface of the roller the ink reservoir. The nozzles may, for example, be configured such that cleaning fluid is sprayed onto the outer surface of the roller. Where multiple nozzles are used, they may be spaced apart in a direction parallel to an axis of the roller to ensure that the cleaning fluid has an even 20 distribution on the outer surface of the roller. In general, the one or more nozzles are connectable to a supply of cleaning fluid that is operable to force the cleaning fluid through the one or more nozzles. A control system may be provided to control supply of the cleaning fluid to the outer surface of the roller. For example, the control system may be configurable to cause cleaning fluid to be supplied through the one or more nozzles 25 in response to a received electrical signal, e.g., the control system may be computer controlled, such as via a wired or wireless connection. The control system may be configured to dispense a predetermined amount of cleaning fluid in response to the received electrical signal, such that excessive use of cleaning fluid can be avoided. Alternatively, the amount of cleaning fluid dispensed may be controlled by an operator 30 or automatically, e.g. based on an amount of ink remaining in the ink fountain and / or ink station assembly, which may be measured by a sensor, such as a colorimeter, configured to measure the amount of ink in the waste solvent. In some implementations, the ink fountain further comprises a scraper blade having an 35 edge for removing ink from the outer surface of the roller and an actuator for moving the 22 07 25 scraper blade or roller between a retracted configuration in which the edge of the scraper blade is spaced apart from the outer surface of the roller and an engaged configuration in which the edge of the scraper blade contacts the outer surface of the roller for removing ink therefrom. The ink fountain may additionally comprise a doctor blade that 5 is spaced apart from the outer surface of the roller to ensure that ink coated onto the outer surface of the roller has an appropriate and uniform thickness. The scraper blade may be operated independently of the doctor blade, e.g. no adjustment of the doctor blade may be necessary when the scraper blade is moved between the retracted or engaged position. An additional one or more nozzles may be provided above the scraper 10 blade (e.g., between the scraper blade and the doctor blade) for supplying cleaning fluid to the scraper blade to remove ink that would otherwise accumulate on the scraper blade. According to a fourth aspect of the present disclosure there is provided a method of cleaning an ink station assembly comprising the ink fountain of the third aspect. The 15 method comprises controlling (e.g., using one or more computers) a source of cleaning fluid to supply cleaning fluid to the outer surface of the roller through the one or more nozzles. For example, the source may comprise one or more valves that can be opened or closed in response to a supplied electrical signal, to turn on or off the supply of cleaning fluid to the nozzle(s). The method may additionally comprise forcing a purge 20 gas (e.g. compressed air) through the one or more nozzles to remove residual cleaning fluid and / or ink. When a scraper blade is present, cleaning the ink station assembly may comprise controlling (e.g. using one or more computers) the actuator to move the scraper blade or 25 roller into the engaged configuration or the retracted configuration. According to a fifth aspect of the present disclosure there is provided an ink station assembly comprising: one or more rollers, including a first roller, operable to transfer ink to a printing plate; and the ink fountain of the first aspect or the third aspect, wherein the 30 ink fountain is configured to transfer ink from the ink reservoir to the first roller through the opening in the ink reservoir. According to a sixth aspect of the present disclosure there is provided a can decorator comprising one or more ink station assemblies according to the fifth aspect. The can 35 decorator may comprise a respective printing plate for each of the ink station assemblies 22 07 25 and, preferably, a blanket wheel comprising a plurality of blankets configured for receiving ink (e.g. a respective ink image or pattern) from each of the printing plates when the blanket wheel is rotated. 5 According to a seventh aspect of the present disclosure there is provided a system comprising: the ink fountain of the first or fourth aspect of the present disclosure, or the ink station assembly of the fifth aspect of the present disclosure; one or more computers; and one or more storage devices communicatively coupled to the one or more computers. The one or more storage devices store instructions that, when executed by 10 the one or more computers, cause the one or more computers to: (i) control a source (supply) of cleaning fluid to supply cleaning fluid through the one or more nozzles of the ink fountain; and / or (ii) control an actuator to move the scraper blade into the engaged configuration or the retracted configuration. The source of cleaning fluid and / or the actuator may be part of the system. 15 According to an eighth aspect of the present disclosure there is provided one or more non-transitory computer storage media (e.g. a computer program product) storing instructions that when executed by one or more computers cause the one or more computers to: (i) control a source of cleaning fluid to supply cleaning fluid through the 20 one or more nozzles of the ink fountain of the first or fourth aspect of the present disclosure; and / or (ii) control an actuator to move the scraper blade of the ink fountain of the first or fourth aspect of the present disclosure into the engaged configuration or the retracted configuration. 25 The details of one or more embodiments of the subject matter of this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims. 30 BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawing in which corresponding reference numbers and designations indicate corresponding parts, and in which: 35 FIG. 1 is a schematic side section view of a can decorator; 22 07 25 FIG. 2 is a schematic perspective view of an ink station assembly of the can decorator; FIG. 3 is a schematic front perspective view of an ink fountain of the ink station assembly; FIG. 4 is a schematic rear perspective view of the ink fountain; FIG. 5 is a schematic front perspective view of the ink fountain of FIG. 2 with the ink 5 reservoir removed; and FIG. 6 is a schematic perspective side section view of the ink fountain installed in the ink station assembly in the can decorator. DETAILED DESCRIPTION 10 FIG. 1 is a schematic side view of a can decorator 100 that comprises a plurality of ink station assemblies (“ink stations” or “inkers”) 102, in this example eight ink station assemblies 102, spaced apart from one another circumferentially around a blanket wheel 104 on which a plurality of blankets 106 is mounted. The can decorator 100 is configured 15 to rotate the blanket wheel 104 to bring each blanket 106 into contact with successive print cylinders 108 that are each supplied with ink from a corresponding one of the ink station assemblies 102. Typically, each print cylinder 108 accommodates, on its outer surface, a printing plate that has a corresponding part of an image or pattern (“artwork”) embossed into its exterior surface, such that the image or pattern is built up on the 20 blanket 106 as the blanket 106 contacts each of the print cylinders 108 in turn. In general, each ink station assembly 102 is configured to provide a different colour ink for inking the corresponding print cylinder 108 and hence the blanket. Once a blanket 106 has been inked, the rotation of the blanket wheel 104 carries the blanket 106 into contact with a can body (not shown), whereby rotation of the can body over the surface of the 25 blanket 106 allows the ink image or pattern to be transferred from the blanket 106 onto the outer surface of the can body. FIG. 2 is a schematic perspective view of an ink station assembly 200 of the can decorator. The ink station assembly 200 comprises a plurality of rollers 202, including a 30 first “fountain” roller 204 and an ink fountain 206 that, in use, transfers ink to the rollers 202, via the first roller 204. The rollers 202, 204 are configured to transfer ink to a print cylinder (not shown in FIG. 2) for inking a blanket of the can decorator. The plurality of rollers 202, 204 collectively provide an “ink train” from the ink fountain 206 to the print cylinder 108. The rollers 202, 204 are arranged to ensure that an appropriate amount of 22 07 25 ink is transferred to the print cylinder and that the ink is distributed evenly over the surface of the print cylinder. FIGS. 3 and 4 are schematic perspective views of the ink fountain 206 of the ink station 5 assembly 200. The ink fountain 206 comprises a housing 302 into which a removable ink reservoir 304 is fitted. In the present example, the housing 302 is open-topped such that the ink reservoir 304 can be lifted into or out of the housing 302, e.g. using one or more handles 306, 308 attached to the ink reservoir 304. The ink reservoir 304 comprises a base portion 310, two sidewalls 312A, 312B and a rear wall 314, which each extend 10 upwards from the base portion 310, and a moveable barrier 316 extending between the two sidewalls 312A, 312B. In the “open” configuration shown in FIGS. 3 and 4, the moveable barrier 316 is spaced apart from the base portion 310 to create an opening 318 through which ink can leave the ink reservoir 304, the ink otherwise being confined within the ink reservoir 304 by the base portion 310, the two sidewalls 312A, 312B and 15 the rear wall 314. The rear wall 314 slopes downwardly towards the opening 318 such that the ink can flow under gravity towards the first roller 204 when the ink fountain is installed in the ink station assembly 200. The ink reservoir 304 comprises a lip extending outwards from the sidewalls 312A, 312B and the rear wall 314 to support the ink reservoir 304 across the walls of the housing 302. 20 The barrier 316 may be raised or lowered, e.g. using the handle 306 attached to the barrier 316 to vary the size of the opening 318, e.g. to control the flow rate of ink through the opening 318, or to close the opening 318 such that the ink is prevented from leaving the ink reservoir 304. A seal between the barrier and the base portion 310 (and / or the 25 sidewalls 312A, 312B) may be provided to reduce the potential for ink to leak around the barrier, but this is generally not necessary because of the viscosity of the inks used in can decorating. The barrier 316 is supported by opposing rails 320 provided on the each of the sidewalls 30 312A, 312B and within which the barrier 316 is able to slide, although it will be appreciated that other methods of supporting or attaching the barrier 316 can be used. In the open configuration shown in FIGS. 3 and 4, the barrier can be prevented from moving downwards to close the opening 318 by having the handle 316 rest against a strut 322 extending between the sidewalls 312A, 312B. The handle 316 is arranged to 22 07 25 pivot about its points of attachment to the barrier 316 so that it can then be rotated away from the strut 322, allowing the barrier 316 to then be lowered to close the opening 318. The barrier 316, and the edges of the sidewalls 312A, 312B, are curved such that they 5 extend partially around the first roller 204 when the ink fountain 206 is installed in the ink station 200, i.e. the barrier 316 and the edges of the sidewalls 312A, 312B extend outwards from the base portion 310 of the ink reservoir 304 along a curved path, e.g., a circumferential path with respect to an axis (such as the axis of the first roller 204) located outside the ink reservoir 304. Movement of the barrier 316 to open or close the opening 10 318 follows the curved path. Such a configuration allows the ink fountain 206 to be located close to the first roller 204 when it is installed into the ink station assembly 200, thereby reducing the space required in the ink station assembly 200 for the ink station 206. 15 FIG. 5 is a schematic front perspective view of the ink fountain 206 with the ink reservoir 304 removed so that the interior of the housing 302 is visible. The interior surfaces of the housing 302 generally correspond to the outer surfaces of the ink reservoir 304 such that the ink reservoir 304 is supported by the housing 302. For example, the housing 502 comprises a sloping rear wall 502 for supporting the sloping rear wall 314 of the ink 20 reservoir 304. The housing 302 is open on a side opposite the rear wall 502 so that the ink can be transferred to the first roller 204 through the opening 318 in the ink reservoir 304 when the ink station 306 is in use. The sloping rear wall 502 of the housing 302 comprises a plurality of nozzles, which in 25 this example are arranged as first and second nozzle arrays 504A, 504B, for directing cleaning fluid (e.g. a solvent for the ink, such as ethanol) through the open side of the housing 302 and onto the first roller 204. The nozzles are arranged to direct cleaning fluid onto different parts of the first roller 204 to remove ink efficiently from the first roller 204. In the example shown, the nozzles are be spaced apart from one another along a 30 direction parallel to the axis of the first roller 204 so that different sections of the first roller 204 receive cleaning fluid from a corresponding one or more of the nozzles. The first nozzle array 504A is arranged (oriented) such that, in use, cleaning fluid supplied by the first nozzle array 504A strikes the first roller 204 at a different height and / or at a different angle from cleaning fluid supplied by the second nozzle array 504B. In the 35 present example, the diameter of the holes is 1.5 mm and the cleaning fluid is supplied 22 07 25 through tubes extending through the housing 302 (as can be seen best in FIG. 6). A purge gas (such as air) may be forced through the nozzles 504A, 504B after the cleaning fluid has been supplied to remove remaining cleaning fluid and / or ink. A control system to switch between cleaning fluid and purge gas may be provided, such that purging may 5 be carried out automatically, e.g. as part of a pre-programmed cleaning cycle. The housing 302 comprises a doctor blade 506 that extends over the base portion 508 of the housing 302 and outwards through the open side of the housing 302. In use, the doctor blade 506 extends to almost touch the first roller 204, but is spaced apart from 10 the outer surface of the first roller 204 by a small amount so that so that a thin layer of ink can be maintained on the first roller 204, with excess ink being removed by the doctor blade 506. The thickness of the layer of ink can be varied by moving the doctor blade 506 towards or away from the first roller 204 using an adjustment mechanism, which in this example, comprises actuator arms 510 attached to the outside of the sidewalls of 15 the housing 302. The base portion 508 of the housing 302 and the doctor blade 506 comprise drainage holes 512 that allow cleaning fluid and ink to be rapidly expelled from the ink fountain 206 during cleaning of the first roller 204. The fluid(s) pass through the drainage holes 20 512 into a removable drip tray 322 (best seen in FIG. 4) located beneath the base portion 506 of the housing 302. The drainage holes 512 are generally aligned so that the cleaning fluid and ink can pass directly into the drip tray 322. The underside of the ink reservoir 304 has locator pins (i.e. protruding members) that are aligned with the drainage holes 512 to help seat the ink reservoir 304 in the correct location within the 25 housing 302. The ink fountain 206 further comprises a scraper blade 514 mounted beneath the base portion 508 of the housing 302. The scraper blade 514 is used for cleaning ink from the first roller 204 (in contrast to the doctor blade 506, which is used to produce a thin film of 30 ink on the first roller 204 and does not contact the first roller). During normal use of the ink station assembly 200, the scraper blade 514 is retracted so that is spaced apart from the first roller 204. A further array of nozzles 504C for supplying cleaning fluid to the first roller 204 is located within the base portion 508 of the housing 302. The scraper blade 514 is preferably located below the nozzles 504C so that the scraper blade 514 can be 22 07 25 cleaned using the cleaning fluid from the nozzles 504C, e.g. to remove ink that would otherwise build up on the scraper blade 514 during cleaning of the first roller 204. FIG. 6 is a schematic perspective side section view of the ink fountain 206 installed in 5 the ink station assembly 200 in the can decorator 100 with the ink reservoir 304 removed. The scraper blade 514 is shown in FIGS. 5 and 6 in the engaged configuration, in which the scraper blade 514 contacts the first roller 204 in order to remove (scrape) ink from surface of the first roller 204. The scraper blade 514 is moved between the retracted and engaged configurations using an actuation mechanism 516, which in this example is 10 pneumatic. In some implementations, retracting the scraper blade 514 causes the scraper blade 514 to cover the nozzles 504C. Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In particular, while this specification contains 15 many specific implementation details, these should not be construed as limitations on the scope of any invention or on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions.

Claims

22 07 251. An ink fountain for transferring ink to a roller of an ink station assembly of a can decorator, the ink fountain comprising:5 a removable ink reservoir having an opening through which to transfer ink to an outer surface of the roller when the ink reservoir is installed into the ink fountain, the ink reservoir comprising a barrier operable to selectively open or close the opening when the ink reservoir is installed into the ink fountain; andone or more nozzles for supplying cleaning fluid to the outer surface of the roller10 when the ink reservoir is not installed into the ink fountain.

2. The ink fountain of claim 1, wherein the one or more nozzles are covered by the ink reservoir when the ink reservoir is installed into the ink fountain.15 3. The ink fountain of claim 2, wherein the ink reservoir comprises an angled surfacefor directing ink towards the outer surface of the roller and the ink reservoir has a corresponding angled surface for supporting the angled surface of the ink reservoir, the one or more nozzles being provided in the angled surface of the ink reservoir.20 4. The ink fountain of any preceding claim, further comprising one or more drainageholes through which to expel fluid from the ink fountain when the ink reservoir is not installed into the ink fountain.

5. The ink fountain of claim 4, wherein the ink reservoir comprises one or more 25 locator pins corresponding to the one or more drainage holes for aligning the ink reservoir within the ink fountain.

6. The ink fountain of any preceding claim, wherein the opening extends circumferentially with respect to the outer surface of the roller.

307. The ink fountain of any preceding claim, wherein the barrier is movable circumferentially with respect to the outer surface of the roller to open and close the opening.22 07 258. The ink fountain of any preceding claim, further comprising a mechanism for locking the barrier in an open configuration when the ink reservoir is installed into the ink fountain.5 9. The ink fountain of claim 8, wherein the ink reservoir further comprises a handlefor moving the barrier between the open configuration and a closed configuration, the handle being operable to lock the barrier in the open configuration when the ink reservoir is installed into the ink fountain.10 10. The ink fountain of any preceding claim, further comprising a scraper bladehaving an edge for removing ink from the outer surface of the roller, wherein the scraper blade is movable between a retracted configuration in which the edge of the scraper blade is spaced apart from the outer surface of the roller and an engaged configuration in which the edge of the scraper blade contacts the outer surface of the roller for15 removing ink therefrom.

11. The ink fountain of claim 10, further comprising one or more nozzles arranged to direct fluid on to the scraper blade when the blade is in the engaged configuration.20 12. The ink fountain of claim 11, wherein the one or more nozzles arranged to directfluid on to the outer surface of the roller or scraper blade are covered by the ink reservoir when the ink reservoir is installed into the ink fountain.

13. An ink station assembly comprising:25 one or more rollers, including a first roller, operable to transfer ink to a printingplate; andthe ink fountain of any one of claims 1-12, wherein the ink fountain is configured to transfer ink from the ink reservoir to the first roller through the opening in the ink reservoir.3014. A can decorator comprising one or more ink station assemblies according to claim 13.

15. A system comprising:35 the ink station assembly of claim 13;one or more computers; andone or more storage devices communicatively coupled to the one or more computers, wherein the one or more storage devices store instructions that, when executed by the one or more computers, cause the one or more computers to:5 (i) control a source of cleaning fluid to supply cleaning fluid through the one ormore nozzles of the ink fountain; and / or(ii) control an actuator to move the scraper blade of the ink fountain into the engaged configuration or the retracted configuration.22 07 25

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