Patent Description:
Modern cans, such as aluminum beverage cans, are often manufactured in two pieces: a cylindrical container body with integral base and an end that is seamed on to the body after the can is filled with a beverage. The can body is typically formed from a circular metal disk of a <NUM> series aluminum alloy (as defined by the industry standard International Alloy Designation System) using a drawing and ironing process. The end includes an opening mechanism, such as an "easy-open" tab or a full-aperture-type pull tab.

Graphics and text are printed on can bodies, such as beverage can bodies, at commercial speeds by rotating machines referred to as decorators. During the printing process in a decorator, mandrels hold can bodies that are placed into rolling contact with print blankets on a rotating blanket wheel. Can bodies are fed onto a turret wheel, also known as a mandrel wheel or a spindle disk, of a decorator typically either through an infeed chute or through an infeed turret. In an infeed chute configuration, a continuous stream of cans is fed from conveyor track work into an infeed section of the can body decorator. In a conveyor stack, the can bodies have a linear "pitch," which is the distance between the center centers of adjacent can bodies. The pitch dimension is typically approximately the outside diameter of the can body.

Individual can bodies can be separated from the conveyor stack by a pocketed single rotating turret wheel or starwheel that retains the can bodies in pockets via vacuum. Many decorators include a separator turret that receives can bodies from the infeed device to increase the pitch such that the pitch and peripheral speed of the cans match that of the turret wheel. Often, while on the turret a can body is held in a pocket on a mandrel wheel and is then drawn by vacuum longitudinally onto a mandrel.

For example, <CIT> discloses an infeed system that directs cans into cradles in a pocket wheel. The pocket wheel rotates with a mandrel wheel such that a can body in a pocket of a pocket wheel can be transferred onto the corresponding mandrel of the mandrel wheel.

Often, <NUM> or <NUM> mandrels are mounted to the mandrel wheel assembly or the spindle disk assembly. In many commercial decorators, the mandrel wheel assembly is rotated by gearing that is driven by the main gearing from the blanket wheel assembly. The rotational speed of the mandrel wheel assembly matches, and in this regard determines, production output of the decorator.

While the can bodies are mounted on the mandrel, the can bodies are printed with up to eight colors (or more for some machines) in an offset printing process. In the printing process, a discrete ink reservoir of each inker assembly supplies ink (typically of a single color) to a print plate on the circumference of a print plate cylinder. Ink is transferred from the print plates, which typically have artwork etched into their surfaces, to printing blankets on a blanket drum assembly. The printing blankets on the circumference of a rotating blanket drum assembly transfer graphics and text from the blanket to the cans while the cans are on the mandrels of the rotating mandrel wheel assembly. In this regard, the co-operation of the blanket drum assembly and the mandrel wheel assembly transfers colored images from the print blankets to the can bodies.

Some prior art inking configurations include rollers that oscillate back and forth. To achieve the linear motion, the oscillating roller includes a pivoting lever mechanism that cooperates with machine elements, such as a cam. In some configurations, the linear motion of an oscillating roller is achieved by a discrete cam mounted directly on the oscillating roller shaft axis. Further, prior art oscillating roller systems typically have support bearings that are lubricated via a total loss grease system or a total loss oil system.

After rotating the can bodies past the printing blankets, the mandrel wheel carries the mandrels and can bodies to an over-varnish unit, where the contact between the can bodies and an over-varnish applicator roller applies a protective film of varnish over the graphics and text previously applied by the blankets. Over-varnish is often referred to as "OV". The coatings applied over the decorated can body in the over-varnish unit are well known.

As explained above, can bodies, when engaged with the printing blankets and with the over-varnish unit, are located on rotating mandrels. Conventional mandrel wheels have a system to determine when a can body is misloaded on the mandrel. The term "misloaded" is used herein to refer to a can body and/or a mandrel where the can body is either not fully seated on the mandrel, no can is loaded on the mandrel, and/or like failures of loading of the can bodies onto the mandrels). Prior art mandrel wheels often include a mandrel trip system that retracts a misloaded mandrel inwardly sufficient to prevent the misloaded mandrel from engaging with the printing blanket.

The mandrel rotational speed when engaged with the over-varnish applicator roller is one condition that determines the magnitude of angular contact between the can and the applicator roller, which is measured in units of "can wraps" that are equivalent to the circumferential length of the can body. The contact period between the can body and the over-varnish applicator roller is a fixed boundary condition - that is, the period is a fixed proportion of <NUM> degrees of mandrel wheel rotational movement.

Varnish is applied to the can body through contact between the can body and the over-varnish applicator roller. The over-varnish applicator roller is an element of the over-varnish assembly. <FIG> illustrate a typical arrangement of the over-varnish unit that includes an enclosure, a fountain well, a gravure roller, and an over-varnish applicator roller. A metered supply of over-varnish is delivered to the over-varnish applicator roller through the over-varnish unit fountain well and gravure roller machine elements.

Varnish mist is heavy at roller contact points and in the region of the over-varnish unit fountain well. The over-varnish enclosure contains varnish misting caused by the fountain well and contact between gravure roller and over-varnish applicator roller.

In order to achieve process accuracy in the parameters of varnish thickness and varnish weight applied to a can body, the surface speeds of the gravure roller, over-varnish unit applicator roller, and the mandrel/can body are designed to be identical. After the application of varnish at the over-varnish unit, the can bodies are transferred from the mandrels to a transfer wheel and then transferred to a pin chain for curing.

Prior art mandrels are rotated by contact either with a mandrel drive tire, which is mounted on a shaft common with the over-varnish applicator roller, or a mandrel drive belt which contacts the mandrels prior to them contacting the applicator roller. The over-varnish applicator roller, mandrel drive tire and mandrel drive belt are all partially enclosed within the over-varnish enclosure.

Printing beverage cans requires exacting alignment, even after label changes. The quality of the print reflects the alignment of the plate cylinder and printing blankets, among other parts. The alignment or registration is typically judged by inspection of decorated can bodies sampled at the region of the decorated can exit pin chain conveyor. Typically, manual print registration operations are carried out in the region of the color section. This requires either one machine operator to move across the beverage can printing machine between the pin chain conveyor and print registration area, or two machine operators to work co-operatively in a high noise environment.

Typically, axial and circumferential registration is performed by manual movement (that is, by a person's hands) at the mounting interface between the plate cylinder shaft and the plate cylinder. The plate cylinder shaft is a machine element rotationally driven about its own axis and geared to the blanket drum assembly rotational movement.

Another approach is to manually adjust parallel axes lead screws that co-operate with parallel axis-arranged axial and circumferential registration adjustment assemblies, or to manually adjust co-axial lead screws co-operating with circumferential and axial registration adjustment assemblies. <CIT> describes a can decorating apparatus comprising multiple station ink supply and transfer apparatus for transferring ink from an ink fountain to a blanket wheel through a plate cylinder with ink image registration adjustment apparatus and axial and circumferential tightness control apparatus operatively associated with each plate cylinder and each ink supply and transfer apparatus. <CIT> describes a method and apparatus for adjusting the temperature of a printing press.

According to the present invention, an inker assembly of a can decorator according to claim <NUM> is provided, said inker assembly comprising: an ink well; plural laterally-fixed roller assemblies, each laterally-fixed roller assembly comprising a roller configured to rotate about an axis and having a fixed position along the axis; plural oscillating roller assemblies, each oscillating roller assembly including an oscillator body, an oscillator shaft supporting the oscillator body, and a cam follower coupled to the oscillator shaft; the oscillating roller assemblies and the laterally-fixed roller assemblies configured for cooperation to transmit ink from the ink well to a plate cylinder of the can decorator; a cam body having a cam that is engaged with at least one of the cam followers of the oscillating roller assemblies; and a cam drive transmission for rotating the cam body and cam; whereby rotation of the cam body moves the at least one of the cam followers fore and aft, thereby moving the oscillator shaft and oscillator body fore and aft.

The oscillating roller assemblies can include an upper oscillating roller assembly, a left oscillating roller assembly, and a right oscillating roller assembly that are oriented circumferentially about the cam body such that each one of the upper, left, and right oscillating roller assemblies is engaged with the cam. The oscillating roller assemblies can be equally spaced about a pitch circle diameter having a center that is coincident with a longitudinal axis of the cam body. The body of the oscillating roller assemblies have internal passages configured for water cooling.

The cam drive transmission can include a cam drive gear mounted on the cam body and a gear train configured for transmitting torque to the cam drive gear. The cam body can include a cam body idler gear coupled to the cam body. And each one of the upper, left, and right oscillating roller assemblies can include an oscillating roller drive gear engaged with the cam body idler gear.

Each one of the cam follower supports can be slidably coupled to the inker assembly frame such that the cam follower is restricted to rotation about a oscillating roller assembly longitudinal axis and translation along the oscillating roller assembly longitudinal axis. The laterally-fixed roller assemblies can include a left distributor roller assembly and a right distributor roller assembly, the left distributor roller assembly engaged with the upper oscillating roller assembly and the left oscillating roller assembly, the right distributor roller assembly engaged with the upper oscillating roller assembly and the right oscillating roller assembly. Further, the laterally-fixed roller assemblies can include a left form roller assembly and a right form roller assembly, the left form roller assembly is engaged with the left oscillating roller assembly, the right form roller assembly is engage with the right oscillating roller assembly, and each one of the left and right form roller assemblies engage the plate cylinder.

Each one of the oscillating roller assemblies can include at least one support bearing mounted to an inker assembly frame. And each oscillating roller assembly support bearings can include a lubrication system that includes a housing, a supply system that feeds lubricant into an inlet plenum formed in the housing, and a return system for enabling discharge of lubricant from an outlet plenum. The lubrication system may be a closed loop lubrication system that is configured for supplying lubricant to the oscillating roller assembly support bearings and receiving lubricant from the oscillating roller assembly support bearings.

Also described herein a system comprising one or more of the above described inker assembly and an ink cooling system configured for cooling the inker assemblies, the ink cooling system comprising: a recirculating chiller configured for transferring heat from the ink to a coolant; a temperature sensor in a coolant outlet from at least one of the inker assemblies; and a valve configured to control coolant flow rate in response to data from the temperature sensor to regulate ink temperature to a target temperature.

The temperature sensor can be a single temperature sensor at an outlet of one of the inker assemblies such that a signal from the temperature sensor represents the coolant outlet temperature of the single inker assembly. Alternatively, the inker assemblies can include plural inker assemblies, and the temperature sensor can be a single temperature sensor in a common flow of all or a portion of the inker assemblies. Or the inker assemblies can include plural inker assemblies, and the temperature sensor can be plural temperature sensors, such that each inker assembly includes one temperature sensor (that is, each inker assembly has its own temperature sensor), and each one of the inker assemblies has its own control valve, thereby enabling coolant temperature control of ink to each inker assembly independent of coolant temperature control of ink to the other inker assemblies.

Each one of the inker assemblies can include at least one roller through which the coolant flows to indirectly cool the ink in contact with the at least one roller.

A can body decorating machine or decorator <NUM> for printing text and graphics on can bodies, such as beverage can bodies <NUM>, includes a structural frame <NUM>; an infeed assembly <NUM>; a print assembly <NUM>; a color assembly <NUM> that includes a print registration system <NUM>, a temperature regulation system <NUM>, and an inker array <NUM>; an over-varnish assembly <NUM>; and a discharge assembly <NUM>. Some subsystems of decorator <NUM> are illustrated in <FIG>.

Can bodies <NUM> in the embodiment shown in the figures are beverage can bodies, which are drawn and wall ironed can bodies having a base that includes a domed bottom surface inside of a standing ring, a cylindrical sidewall that extends upwardly from the base, and a circular opening opposite the base. The can bodies <NUM> handled by the infeed assembly <NUM> typically have an exterior that is uncoated aluminum, sometimes referred to as bright cans. It is anticipated that can bodies <NUM> are prepared for coating in decorator <NUM> by conventional preparation and handling techniques that are well known to persons familiar with decorating cans at commercial speeds, often over <NUM>,<NUM> cans per minute and approximately <NUM>,<NUM> cans per minute. Can decorator throughput is chosen to match the upstream and downstream processes such that <NUM>,<NUM> cans per minute is not a practical upper limit, as a modern decorator <NUM> can achieve greater throughputs (such as <NUM> cans per minute) depending on many parameters.

Beverage can bodies <NUM> typically have a thin sidewall, such as below <NUM> inches thickness and often approximately <NUM> inches thickness for conventional <NUM> ounce, drawn and ironed (DWI) beverage cans. Because of the thin wall and the open end, can bodies can be subject to crushing or plastic deformation, especially from a transverse (that is, normal to longitudinal) load. Typically, the can bodies are formed of a <NUM> series aluminum alloy (as defined by the industry standard International Alloy Designation System). The present invention is not limited to any can body configuration, but rather encompasses can bodies of any type, such as (for non-limiting example) drawn and ironed beverage or food cans of <NUM> (<NUM>), <NUM> (<NUM>), and <NUM> (<NUM>) nominal (diameter) size; three piece cans of any commercial size; aerosol cans of <NUM> (<NUM>), <NUM> (<NUM>), and <NUM> (<NUM>); open-top or seamed can bodies; aluminum, such as <NUM> series aluminum alloy, tin plate, steel can bodies; and others.

Structural frame <NUM> includes a base <NUM> and a machine frame <NUM>, which includes a planar rear face <NUM> and an opposing front face <NUM>, as illustrated schematically in <FIG> and <FIG> and best shown in <FIG>. In this regard, the term "front" refers to the side of the machine having the blanket wheel of the color assembly <NUM> and the terms "back" and "rear" refer to the side opposite the front, which in the embodiment shown includes the main drive motor. Faces <NUM> and <NUM> are enclosed by sidewalls so as to support components of the decorator <NUM>. A portion of the frame <NUM> may be extended to support infeed assembly <NUM>, as illustrated schematically in <FIG>. Plural fixed cylindrical supports <NUM> extend from an inboard portion of front face <NUM> for supporting the print cylinder assemblies <NUM>, as described more fully below. Frame <NUM>, as well as supports <NUM>, may be formed of cast iron or steel and/or by carbon steel fabrications or a combination of both, as well understood by persons familiar with rotating machinery.

<FIG> illustrates a first embodiment infeed feed assembly <NUM> that includes an infeed chute <NUM>. Infeed chute <NUM> in the embodiment in the figures includes a vertical portion <NUM> that holds and guides can bodies <NUM> in a horizontal, stacked orientation (that is, the longitudinal axis of each can body <NUM> is horizontal), a curved portion <NUM> at the base of the vertical portion <NUM>, and a chute outlet/mandrel wheel infeed <NUM>.

<FIG> illustrates a second embodiment infeed assembly <NUM>' that includes an infeed chute <NUM>' and an infeed turret <NUM>'. Infeed chute <NUM>' includes a vertical portion <NUM>' that holds and dispenses can bodies in a horizontal orientation and a can outlet <NUM>' at a lowermost end of vertical chute <NUM>'. Pockets <NUM>' of infeed turret <NUM>' pick up can bodies from the can outlet <NUM>'.

Infeed turret <NUM>' rotates (counter-clockwise in the orientation shown in <FIG>) to carry can bodies in pockets <NUM>' about the outboard circumference of the starwheel or turret <NUM>'. Pockets <NUM>' are curved-cradle like structures that are evenly spaced about the perimeter of turret <NUM>' and include a vacuum inlet to retain the can bodies <NUM> in the pockets <NUM>' under vacuum pressure. The pocket structure can be conventional, as will be understood by persons familiar with can body handling in decorators. Can bodies <NUM> are handed off from infeed turret <NUM>' at an infeed point <NUM>' to a mandrel wheel <NUM> of the print assembly <NUM>. The mandrel wheel <NUM> is rotating clockwise (in the orientation in <FIG>) to carry the can bodies <NUM> into contact with the print blankets. The angular positions of the infeed point <NUM> or <NUM>' and other working points about the circumference of the mandrel wheel, such as the point at which the can bodies contact the print blankets, contact the over-varnish applicator roller, retract from the print-ready position, discharge from the mandrel wheel, and the like, may be chosen as explained below.

The mandrel wheel assembly <NUM> includes a mandrel starwheel or mandrel wheel turret <NUM> and mandrel assemblies <NUM>. Mandrel wheel turret <NUM> includes curve-cradle- shaped, peripheral recesses or pockets <NUM> that receive can bodies <NUM> from infeed system <NUM>/<NUM>'. As turret <NUM> rotates about an axis defined by a mandrel wheel shaft <NUM>, a vacuum is applied at each pocket <NUM> to retain the can body <NUM>. The structure forming pocket <NUM> is not symmetrical about a radial line to enhance its ability to pick up can bodies <NUM>, as is conventional.

In the embodiment illustrated in the figures, the mandrel wheel <NUM> is driven by its own mandrel wheel drive (not shown in the figures) that includes a mandrel wheel drive motor. Other configurations, such as gearing transmitting torque from the main drive system <NUM> are contemplated.

At commercial decorator speeds, loading the can bodies <NUM> onto the mandrels <NUM> repeatably without error can be a challenge. Incorrectly loaded can bodies can cause excessive spoilage, machine downtime, and in some cases damage to parts of the mandrels, printing blankets, or other components.

Pockets <NUM> are configured and spaced such that each pocket <NUM> aligns with a corresponding one of the mandrels <NUM>, as illustrated in <FIG> and <FIG>. Can bodies <NUM> are transferred longitudinally from pockets <NUM> of the mandrel wheel <NUM> onto the mandrels <NUM> by vacuum. Each mandrel <NUM> is capable of rotating about its longitudinal axis, as is well known. As mandrel wheel <NUM> carries the can bodies <NUM> into engagement with printing blankets <NUM> of the blanket drum assembly <NUM>, mandrels <NUM> rotate as needed in response to contact with the printing blankets.

Mandrel assembly <NUM> includes individual mandrels <NUM> and mandrel arm assemblies <NUM>, which include mandrel trip assemblies <NUM>. Mandrel assembly <NUM> rotates on shaft <NUM> in common with turret <NUM>.

Mandrel arm assemblies <NUM>, shown schematically in <FIG>, carry mandrels <NUM> and include the mandrel trip assemblies <NUM>. Arm assemblies <NUM> carry the mandrels <NUM>, and when loaded, also can bodies <NUM>, about the circumference of mandrel wheel <NUM>. While carried by the arm assemblies <NUM>, mandrels <NUM> follow a predetermined path that may be chosen according to known parameters. The arm assemblies may also enable the mandrels to radially retract, as needed, to apply desired contact pressure of a can body <NUM> with a print blanket <NUM>. Further, the mandrel trip assembly <NUM> retracts the mandrel <NUM> from a print-ready position (that is, a diametral position at which a can body <NUM> contacts a print blanket during normal printing) to a retracted or bypass position (that is, in which the diametral position - reflected in the radial distance of the mandrel <NUM> from the axis of shaft <NUM> - at which a can body <NUM> does not contact the print blanket) upon sensing that the mandrel or can is misloaded.

The present invention is not intended to be limited to the structure of any particular mandrel arm assemblies or manual trip assemblies disclosed herein unless expressly required by the claim. Rather, the present invention encompasses any structure and method relating to the arm assemblies and trip assemblies consistent with the functions described herein.

In current decorators, there are two main types of systems for mandrel trip. First, in a "carriage trip" system, the mandrel wheel assembly separates from the blanket drum such that the mandrels, as a whole, do not engage the print blanket. Second, in a "single mandrel trip" system, individual mandrel assemblies are capable of moving independently of other mandrels assemblies to retract from a print-ready position (that is, a position, including a radial position or dimension on the mandrel wheel, in which a mandrel/can body is about to engage a print blanket of the blanket wheel). The term retract preferably includes diminishing the radial or diametral position of the mandrel using well known features of can decorator mandrel wheels.

Decorator <NUM>, in the embodiment of the figures, has 'single mandrel trip' functionality and features, in which individual mandrels may independently 'trip' out of their print-ready position to avoid any of the mandrels, if misloaded, being printed when no can is present or the can is not loaded sufficiently or the can is defective. Points that define an angular or circumferential position on the mandrel wheel <NUM> are explained below. The angle range(s) provided below, which are larger than those in conventional beverage can decorators, are chosen to address problems associated with increasing throughput of beverage can decorators, such as approaching or (in the future) exceeding <NUM> can bodies per minute.

<FIG> is an enlarged view of decorator <NUM> illustrating an infeed configuration. The infeed system is shown only for illustration, as it is not intended that the structure or functional details limits the scope of the invention relating to the mandrel wheel unless expressly set out in the claims. A point A - referred to as the infeed point -- defines the point relative to mandrel wheel <NUM> at which the can bodies <NUM> are released from infeed system <NUM>/<NUM>' to load onto the mandrel wheel <NUM>. Each pocket <NUM> includes a passage or hole through which vacuum is pulled to urge the can body <NUM> onto the mandrel pocket <NUM> and to retain can body <NUM> in pocket <NUM>, as explained above. Typically, a guide is provided to push the can body <NUM> towards the mandrel <NUM> from pocket <NUM> of the mandrel wheel <NUM> after or downstream of point A. Point B - referred to as the seated point -- is the circumferential point on the mandrel wheel assembly <NUM> at which the can body <NUM> should be fully seated or loaded onto the mandrel <NUM>. As explained above, vacuum may be employed to load or aid in loading each can body <NUM> onto the corresponding mandrel <NUM>. A sensor <NUM>, which preferably is conventional and is illustrated schematically, at point B detects whether the can is fully and appropriately loaded onto the mandrel. Any conventional sensor may be employed, as will be understood by persons familiar with conventional decorator technology.

At point C - referred to as the trip point -- air pressure is used to remove (that is, blow off) a can from the mandrel if the can is detected by the sensor at B as incorrectly loaded onto the mandrel or otherwise so defective that the sensor <NUM> identifies it as requiring removal, thus preventing possible damage to the printing blankets and other equipment. Also at point C, a misloaded mandrel is 'tripped' out of print position by mandrel trip mechanism <NUM> to avoid printing the surface of a misloaded mandrel <NUM> when no can body <NUM> is present. Trip mechanisms <NUM> are known in the art, and the present invention contemplates employing any trip mechanism. At point D - referred to as the printing point -- the can bodies <NUM> are printed by engagement between the can bodies <NUM> and the print blankets <NUM>. For accuracy, point D may be defined by the point of initial contact of the can body with the print blanket <NUM>.

At point E - referred to as the reset point -- any misloaded mandrels which were tripped out of the print-ready position are reset to their default diametral position to allow further can bodies <NUM> to be loaded onto the mandrel wheel <NUM>. As explained below relative to the over-varnish unit, can bodies are discharged from mandrel wheel <NUM> to the discharge system <NUM>.

The above sequence of mandrel wheel events requires precise timing and coordination between pneumatic & mechanical systems to occur correctly. At high speeds (particularly as machine speeds approach <NUM> can bodies per minute) there is a danger that there is not sufficient time to perform them correctly, at least without very precise setup by skilled operators. In this regard, the time between points A and D (that is, betting loading of the can bodies <NUM> onto the mandrel wheel and printing) must be sufficient to achieve loading, verification of loading and sensing errors, and tripping (if needed), but is constrained by the requirement that the can bodies <NUM> pass through the over-varnish unit after engagement with the print blanket <NUM>, and then have sufficient time for the reset step for the retracted mandrels (after the over-varnish unit) before the mandrel loading process begins again. The master cam (for controlling the path of the mandrels) for such a procedure must also be designed to achieve the functions described herein. Ultimately, this acts as an upper limit to the speeds the machine can be expected to run under normal operating conditions.

The stated angle, especially angle A-D in the range of <NUM> to <NUM> degrees, is such that the decorator machine <NUM> can be suitable (as the inventors surmise) to run at high speed (approximately 2000cpm), is easier to set up as the process window reflected by the angle is opened, and less liable to produce scrap can bodies. To achieve the structure and function described herein, a master cam profile is designed, such as according to complex cam profiles (for example, 7th order polynomial curves), as will be understood by persons familiar with beverage can decorator design in view of the present disclosure.

Thus, the inventors surmise that to allow the machine to run at higher rotational speed and higher can throughput, and to be easier to set and to be less liable to create spoilage, the time interval (and therefore the angle A-D at a given mandrel wheel rotational speed) between the infeed & the print position is increased in the current invention. The angle A-D is set by the design of the 'master cam' (which controls the relative motion of the decorator parts); altering the design of the master cam allows more time between points A and D. Designing the master cam to optimize angle A-D, while also choosing angle E-A, to increase angle A-D to within a range, for example, of <NUM> degrees to <NUM> degrees gives the current invention an advantage over existing machines. The structure of the master cam (not shown in the figures) and engineering the master cam to achieve the functions described herein will be understood by persons familiar with can decorator technology in view of the present disclosure.

Color assembly <NUM> is supported by machine frame <NUM> and includes a main drive <NUM> (<FIG>), a blanket drum or blanket wheel assembly <NUM>, plate cylinder or print cylinder assemblies <NUM>, a print cylinder registration system <NUM>, a temperature regulation system <NUM>, and an arrays of inker assemblies <NUM>. Main drive <NUM> includes a motor and gearbox <NUM> that is mounted to frame rear face <NUM> and a main drive gear <NUM>, which preferably is helical, as described more fully below.

Blanket wheel assembly <NUM> includes a horizontal main shaft <NUM> (indicated in relief in <FIG> and <FIG>) that is common with main drive gear <NUM> and supported by bearings (not shown in the figures). A drum or wheel <NUM> is mounted to shaft <NUM> such that drive <NUM> rotates wheel <NUM> at a desired rotational speed. A periphery of wheel <NUM> includes several pads <NUM> that are curved or circumferentially shaped such that the radially outboard surface of the pads <NUM> lie on the circumference of wheel <NUM>. Blanket wheel pad <NUM> can be a conventional print pad for receiving ink decoration from the plate cylinder <NUM>.

Print cylinder assemblies <NUM> and inker assemblies <NUM> are housed or supported by machine frame <NUM> such that wheel <NUM> rotates relative to the print cylinder assemblies <NUM> and inker assemblies <NUM>. Each inker assembly <NUM> of the array is associated with one color ink and each inker is associated with its own print cylinder assembly <NUM> such that each plate cylinder <NUM> can apply a single color to each print cylinder <NUM>, which then transfers its single-color image to the rotating blanket <NUM>. Each one of the plate cylinders <NUM> can have a unique pattern, image, text, and like that corresponds to the desired color that when combined provides a complete can decoration to the blanket <NUM>. As blanket <NUM> contacts plate cylinder <NUM>, plate cylinder <NUM> rotates approximately one revolution. The blankets and plate cylinder materials and structure can be conventional. In <FIG>, eight print cylinder assemblies are schematically shown. In <FIG>, only one print cylinder assembly is shown for clarity, as it is understood that the seven openings in the housing wall <NUM> in <FIG> preferably houses print cylinders. The present invention encompasses a decorator having any number of print cylinders according to well-known parameters, such as the desired number of colors to be applied to the can bodies.

As illustrated best in <FIG>, each print cylinder assembly <NUM> includes a print cylinder shaft <NUM> having a tapered distal end surface <NUM> on which a plate cylinder <NUM> (shown by a relief line in <FIG>) is mounted. The taper at surface <NUM> is optional, as other means for joining shaft <NUM> to plate cylinder <NUM> are known. Shaft <NUM> extends from an interior of the machine frame <NUM> through front face <NUM> such that end surface <NUM> is exterior to or outside of the enclosure of frame <NUM>. Print cylinder shaft <NUM> is supported by a main bearing <NUM> that is supported by front face <NUM> and internal bearings (not shown in the figures) located between print cylinder shaft <NUM> and an inboard surface of sleeve <NUM>.

Frame <NUM> includes the hollow, cylindrical print cylinder structural support <NUM> that extends inwardly from the front face <NUM>. A print cylinder sleeve <NUM> is located within support <NUM> and is capable of movement relative to support <NUM>. In the embodiment of the figures, sleeve <NUM> (as best shown in <FIG>) is prevented from rotation by a spring-loaded support that is affixed to a portion of the machine frame and the sleeve. Accordingly, sleeve <NUM> does not rotate with print cylinder shaft <NUM>. Rather sleeve <NUM> is capable of axial translation, which translation (forward and rearward) is imparted to print cylinder shaft <NUM> and print cylinder <NUM>. The magnitude of axial translation of sleeve <NUM> may be chosen according to the desired magnitude of axial registration of print cylinders <NUM>. Sleeve <NUM>, in some embodiments, is capable of a small amount of angular movement or rotation to accommodate circumferential registration.

A helical gear <NUM> is mounted on shaft <NUM> within housing frame <NUM> and aligned to engage main drive gear <NUM>, which can be driven by main drive motor <NUM> and gearbox <NUM>. During operation, main gear <NUM> drives shaft <NUM> through helical print cylinder gear <NUM>, as shaft <NUM> rotation is supported by bearing <NUM> and internal bearings.

As explained above, while the can bodies <NUM> are on the mandrel wheel assembly <NUM>, a can body is brought into contact with a blanket <NUM> of rotating blanket wheel <NUM> to transfer the ink from blanket <NUM> to the outer surface of the can body <NUM>.

Can bodies <NUM>, after contact with the printing blankets <NUM>, receive an over-varnish from the over-varnish system <NUM>. The cans exit the mandrel wheel assembly <NUM> after the over-varnish application when they are handed off to discharge assembly <NUM>.

The print plates <NUM> of beverage can decorators are typically registered -- that is, aligned with a high and repeatable degree of accuracy -- to a common datum such that the specified artwork design is accurately transferred onto print blankets <NUM>. Each one of the print plates <NUM> is registered with other ones of the print plates both axially (that is, longitudinal along axis of rotation of the plate cylinder <NUM> and can bodies <NUM>) and circumferentially (that is, angularly relative to the rotation of the print blanket and can bodies <NUM>).

In the embodiment of the figures, a registration drive gear train is configured to combine the rotary motion of an axial print registration drive motor <NUM> and a circumferential print registration drive motor <NUM> into a co-axial output-shaft configuration. Rotary motion of an axial registration shaft is converted to linear movement or displacement of an axial registration slide assembly <NUM>, which linear movement or displacement is transferred to the plate cylinder <NUM> through the print cylinder shaft <NUM>. Rotary motion of a circumferential registration shaft is converted to linear movement or displacement of a circumferential registration slide assembly, which linear movement or displacement is transferred to the helical gear <NUM>. Liner movement or displacement of helical gear <NUM> is converted to angular or circumferential movement or displacement of print cylinder shaft <NUM> (to which gear <NUM> is mounted) when pushed against stationary helical main gear <NUM>, which circumferential movement or displacement is transferred to print cylinder <NUM> by print cylinder shaft <NUM>.

As illustrated in <FIG>, an automated print plate registration assembly <NUM> includes an axial alignment or registration assembly <NUM> and a circumferential alignment or registration assembly <NUM>. Axial registration system <NUM> moves plate cylinder <NUM> preferably only by translation in the longitudinal or axial direction. Circumferential registration system <NUM> preferably moves plate cylinder <NUM> only circumferentially, although a small amount of axial movement during circumferential registration may occur in some instances in some embodiments. The present invention is not limited to registrations that each move only axially and only radially. Rather, other configurations, in which one registration system simultaneously registers the plate cylinders both axial and circumferentially coupled with another registration system that registers the plate cylinders in only one of the axial and circumferential configurations may also be employed.

Referring again to <FIG>, axial registration system <NUM> for each one of the plate cylinders <NUM> includes an axial print registration drive <NUM>, an axial registration shaft <NUM> (also referred to as a lead screw in accordance with the embodiment shown in the figures) coupled to an output shaft of drive <NUM> , an axial system slider <NUM>, an axial registration system nut <NUM> that is affixed to slider <NUM> and in a threaded connection with lead screw shaft <NUM>, axial registration assembly linear bearings <NUM> in slider <NUM>, a transfer plate <NUM> that translates with slider <NUM>, and a clamp <NUM> for affixing slider <NUM> to transfer plate <NUM>. Axial system slider <NUM> has a pair of through-holes for mounting linear bearings <NUM> such that slider <NUM> can translate on a pair of fixed, parallel, horizontal, support arms <NUM> that extend from the inboard portion of the front face <NUM> of the machine frame <NUM>. Axial registration drive <NUM> can include a motor <NUM> and a gearbox <NUM> in a housing <NUM> that is mounted to frame <NUM>.

Circumferential print registration system <NUM> for each one of the printing plates or plate cylinders includes a circumferential registration drive <NUM>, a circumferential registration shaft (also referred to as lead screw) <NUM> coupled to an output shaft of drive <NUM> via gears 490a and 490b or other transmission, a circumferential system slider <NUM>, a circumferential system nut <NUM> that is affixed to slider <NUM> and in a threaded connection with lead screw <NUM>, circumferential system linear bearings <NUM> in slider <NUM> for enabling slider <NUM> to translate on fixed support arms <NUM>, a transfer arm <NUM>, a hub <NUM> that is attached to slider <NUM> by transfer arm <NUM>, and a key (not shown in the figures) for affixing a hub bore to driven gear <NUM>. At least one human machine interface panel (HMI) is also provided. The present invention is not limited to the use of gears 490a and 490b. For non-limiting example, a belt and pulley arrangement or a chain and sprocket arrangement are alternative options for the registration drive gear train. The term "transmission" is used to refer to any means for transmitting torque, such as a gear train, belt and pulley system, sprocket assembly, and the like. Circumferential registration drive <NUM> can include a motor <NUM>, a gearbox <NUM>, and a housing <NUM> that is mounted to frame <NUM>.

The axial and circumferential registration slide linear bearings <NUM> and <NUM> can be, for non-limiting example, circular plain bore bearings, prismatic plain bore bearings, ball bush bearings, recirculating ball bush bearings, or recirculating ball prismatic bearings. Lead screws shafts <NUM> and <NUM> are constrained to the machine frame such that shafts <NUM> and <NUM> rotate but do not move axially.

The motors of drives <NUM> and <NUM> may be of any suitable type that is capable of performing the registration functions described herein, such as alternating current induction motor - ac motor, stepper motor or servo motor, direct current motor- dc motor, hydraulic motor or pneumatic motor. Each motor type will be accompanied with the appropriate control system hardware and software logic. A gearbox at the output shaft of the motor may be employed.

The HMI (not shown in the figures) can be any interface that enables a user and/or a control system to actuate one or both of the axial registration system and circumferential registration system.

In the embodiment in the figures, the axial registration drive <NUM> and the circumferential registration drive may be any type that can accurately and repeatably move or index axial registration slider <NUM> and circumferential slider <NUM>, respectively, to desired position. The axial registration drive <NUM> and the circumferential registration drive <NUM> may be arranged on parallel axes, that is, the drives may be mutually parallel. Alternatively (not shown in the figures), the axial print registration drive motor and circumferential print registration drive motor could be arranged on perpendicular axes or in other configurations. Further, the present invention encompasses the registration drive motor being a linear actuation type connected directly to the registration slide assembly, which in some configurations includes the registration lead screw and lead screw nut, or eliminates the registration lead screw and lead screw nut.

In the embodiment of the figures, the circumferential registration lead screw <NUM> and axial registration lead screw <NUM> are arranged co-axially. The circumferential registration lead screw and axial registration lead screw may be, for example, a cut screw thread, recirculating ball track type - also known as recirculating ball screw type. The circumferential registration slide assembly and axial registration slide assembly are configured with accompanying discrete lead screw nut. In the embodiment of the figures, each lead screw nut is constrained to the accompanying registration slide assembly.

Referring again to the embodiment shown in figures, the axial print registration drive <NUM> is coupled to an inline axial registration lead screw (or shaft) <NUM> that is coaxial and inside of the circumferential registration lead screw <NUM>. Shaft <NUM> extends through the body of axial registration slider <NUM> and through axial registration system bearings <NUM>, which preferably are conventional slide bearings. Shaft <NUM> extends through nut <NUM>, which is fixed on slider <NUM>, such that rotation of shaft <NUM> translates slider <NUM>. The term "nut" and "lead screw" are used herein to refer to any type of structure that enables the conversion of rotary motion of the screw or shaft into linear translation.

In operation, actuation of axial drive <NUM> rotates axial registration shaft <NUM>, which translates axial registration slider <NUM> forward or rearward relative to decorator <NUM> (or distally or proximally, respectively, relative to the axial drive <NUM>) on support arms <NUM>.

The circumferential registration drive <NUM> has a gear 490a mounted on an output shaft, shown as the bottom gear in <FIG>, <FIG>. The bottom gear 490a is engaged with an upper gear 490b that is mounted on the circumferential registration shaft <NUM>, through which the axial registration lead screw <NUM> passes. Accordingly, circumferential registration lead screw <NUM> is attached to the upper gear 490b such that rotation of the motor of the circumferential drive <NUM> rotates the lower gear 490a, which transmits torque to the circumferential lead screw <NUM> through the upper gear 490b. The circumferential slider <NUM> is attached to the circumferential lead screw <NUM> as described above. The axial registration slider <NUM> is attached to the axial registration lead screw <NUM> as described above. Thus, the circumferential slide assembly and axial registration slider assembly are inline, and co-axial in the embodiment of the figures, and independently adjustable and capable of independently adjusting the position of print cylinder <NUM>.

Any mechanism for moving the plate cylinder <NUM> based on the axial registration slide assembly <NUM> movement may be employed. And any mechanism for moving the plate cylinder <NUM> based on the circumferential slide assembly movement may be employed. For general example of the axial registration mechanism, there can be a mechanical connection between the first (axial) registration slide assembly and the sleeve associated with the plate cylinder such that fore and aft movement of the registration slide assembly causes fore and aft movement of the plate cylinder.

In the embodiment illustrated in the figures, axial registration slider <NUM> is affixed to a U-shaped, vertically oriented transfer plate <NUM>. A pair of upstanding arms of transfer plate <NUM> are held to a rearward face of axial registration slider <NUM> by a pair of clamps <NUM>. One clamp <NUM> is applied to a left arm of plate <NUM> and the other clamp <NUM> is applied to a right arm of plate <NUM>. A lower portion of plate <NUM> is affixed to sleeve <NUM>. A pair of cam screws <NUM> for holding the clamps <NUM> to transfer plate <NUM> can be eccentric or tapered such that the clamps <NUM> securely retains the transfer plate relative to the axial slider <NUM>. Accordingly, forward or rearward movement of the axial registration slider <NUM> translates sleeve <NUM>, which translates print cylinder shaft <NUM> and plate cylinder <NUM>. Transfer plate <NUM> may be not affixed to sleeve <NUM> such that sleeve <NUM> (in some embodiments) may be free to move circumferentially with print cylinder shaft <NUM> during the circumferential registration system. Other structures, such as springs acting on print cylinder shaft <NUM> to urge the shaft <NUM> rearwardly against transfer plate <NUM>, a mechanical connection between transfer plate <NUM> and sleeve <NUM> and/or print shaft <NUM>, and the like, to enable movement of plate cylinder <NUM> in response to movement of axial registration slider <NUM> is contemplated.

In the embodiment illustrated in the figures, the circumferential registration mechanism <NUM> can include a mechanical connection between the circumferential registration slider <NUM> and hub <NUM>, which includes bearings (not shown in the figures) between an inboard surface of hub <NUM> and plate cylinder shaft <NUM>. Accordingly, print cylinder shaft <NUM> can rotate relative to hub <NUM>, as a housing of hub <NUM> is attached to circumferential registration slider <NUM> by arm <NUM> (as best shown in <FIG>) to prevent the housing of hub <NUM> from rotating.

The hub <NUM>, in this regard, is constrained to have only axial movement relative to the plate cylinder shaft <NUM>, while a rotating, interior portion of hub <NUM> is keyed to plate cylinder shaft <NUM> by a longitudinal key (not shown in the figures). Driven gear <NUM> is also keyed and fixed to the plate cylinder shaft <NUM> via a key in a longitudinal keyway in the interior hub bore. In some embodiments, the key attachments between gear <NUM> and plate cylinder shaft <NUM> may be such that gear <NUM> may be longitudinally slidable relative to shaft <NUM> by a dimension sufficient to enable the circumferential registration without resulting in axial movement of the shaft <NUM>.

Accordingly, rotary motion of the circumferential registration drive gears 490a and 490b causes rotation of the circumferential lead screw <NUM>, which moves circumferential slider <NUM> forward or rearward by interaction with nut <NUM>. The forward or rearward movement of circumferential slider <NUM> is transmitted to the housing of hub <NUM> via the support arm <NUM>. Hub <NUM> translates forward or rearward (depending on the direction of translation of slider <NUM>) relative to print cylinder shaft <NUM> - that is, while hub <NUM> translates, the plate cylinder shaft <NUM> and the plate cylinder <NUM> do not translate (that is, do not move axially). Translation of hub <NUM> translates gear <NUM> relative to shaft <NUM>. As illustrated in the figures, gear <NUM> is helical such that the helical teeth of gear <NUM> are in meshed contact with the helical teeth of main drive gear <NUM>. Gear <NUM> is effectively fixed, either by a mechanical brake, by an electrical brake on the main drive motor, and/or inertia or the like such that translation of driven gear <NUM> relative to main gear <NUM>, which during the registration process is not rotating or rotatable, creates an angular displacement or rotation of driven gear <NUM>. Because gear <NUM> is rotationally fixed via the key, the movement of circumferential registration slider <NUM> and axial displacement of the hub <NUM> causes a shift in timing between the gear <NUM> and drive gear <NUM>, and in this way rotates the print cylinder <NUM> by a desired amount to achieve circumferential registration of print cylinder. Other configurations or mechanisms to achieve the shift in plate cylinder circumference in response to axial movement of the circumferential registration slide assembly are contemplated.

For some embodiments, productivity efficiency can be increased since print registration activity is possible and desirable during can decoration production. The registration system disclosed herein can improve the working environment and safety of machine operators, and the print registration (in some embodiments) can be achieved or realized by a single machine operator using the remote HMI placed in the region of the output from the beverage can printing machine.

According to another aspect of the registration system <NUM>, a feedback system includes an axial registration proximity sensor <NUM> and a circumferential registration proximity sensor <NUM>. Axial registration sensor <NUM> preferably is mounted on axial system slider <NUM>, such as a front-facing portion of the slider <NUM>. Circumferential system sensor <NUM> preferably is mounted on circumferential system slider <NUM>, such as on a front-facing portion of the slider <NUM>.

Sensors <NUM> and <NUM> may be of any suitable type that performs the feedback function described herein. Sensors <NUM> and <NUM> can be, without limitation, one or more inductive proximity sensors (such as eddy current or inductive type), micro switch contact, and linear encoder type registration position sensors that are preferably connected to the corresponding registration slider <NUM>, <NUM>, but may also or alternatively be connected to the plate cylinder shaft assembly. Thus, rotary encoder type registration position sensors <NUM>, if employed, may be connected to the axis common to the registration drive motors <NUM>, <NUM> and/or and registration lead screws <NUM>, <NUM>, may be integral with the motor, and/or may be connected to the plate cylinder shaft assembly or other appropriate location.

The feedback system described herein can mitigate "lost" motion within the print registration mechanism giving high accuracy during print plate registration adjustment. Non-limiting examples of lost motion can include clearance or "play" in the bearings, motors, sliders, and/or lead screws, errors related to hysteresis of the system, other differences between input and expected output, and the like.

For an example of the operation of registration system <NUM>, a user or an automated control system may initiate registration via the HMI or by other means based on information that includes a desired amount of axial adjustment and/or radial adjustment of the particular plate cylinder <NUM> to be registered.

Upon determining the magnitude of circumferential movement desired for the first one of the print cylinders <NUM>, the motor of circumferential registration drive <NUM> is engaged to rotate circumferential registration lead screw <NUM> to translate circumferential registration slider <NUM> on support arms <NUM>. The magnitude of circumferential translation may be measured or sensed by circumferential registration sensor <NUM> if mounted on circumferential registration slider <NUM>, hub <NUM>, or other translating portion of circumferential registration system <NUM> and/or by sensor <NUM> associated with circumferential registration motor <NUM>, axial registration lead screw <NUM>, or other rotating part of axial registration system <NUM>. As explained above, axial displacement of slider <NUM> is converted into circumferential displacement of print cylinder <NUM>.

Upon determining the magnitude of axial movement desired for a first one of the print cylinders <NUM>, the motor of axial drive <NUM> is engaged to rotate axial lead screw <NUM> to translate axial registration slider <NUM> on support arms <NUM>. The translation of slider <NUM> is transmitted to the plate cylinder shaft <NUM>. The magnitude of the axial translation can be measured or sensed by axial registration sensor <NUM> based on translation of the axial registration slider <NUM> and/or sensor <NUM> associated with axial registration motor <NUM>, axial registration lead screw <NUM>, or other rotating part of axial registration system <NUM>. If any axial movement of print cylinder <NUM> occurs during circumferential registration, based on sensor output, the desired magnitude of axial movement may be adjusted for correction. If any circumferential movement of print cylinder <NUM> occurs during axial registration, based on sensor output, the desired magnitude of circumferential movement may be adjusted for correction. Either axial or circumferential registration may occur first, or the registrations may be simultaneous, or in interrupted, alternating sequence.

When the desired magnitude of movement of the first plate cylinder <NUM> in its axial and circumferential orientation is achieved, the desired magnitude of axial and circumferential adjustment of the second plate cylinder <NUM> may be performed according to the above method. Conventional controls systems and techniques may be employed. As needed, each one of the plate cylinders <NUM> may be registered by its own registration system <NUM>, <NUM> until desired image quality is achieved. The registration processes may be iterated as needed.

The description of the structure and function of the print registration system and the corresponding feedback system herein is provided as an example and illustration, as it reflects merely one embodiment. The present invention is not intended to be limited to the particular structure and function in the description (including the drawings) unless expressly set out in the claims. For merely some non-limiting examples, the present invention is not limited to a co-axial configuration of the shafts of the axial and circumferential registration systems, to any configuration of the drive registration gear train, any number of print cylinders of the decorator, to a particular control system or type of control system (if any), and the like.

Offset printing, as illustrated in the figures, relies on the transfer of ink between several different surfaces at each stage of the printing stage. The viscosity of the ink in inker assemblies <NUM> can affect the function of the equipment and the quality of the printing process. The temperature of the ink directly affects its viscosity. In some circumstances, ink temperatures may be higher or lower than preferred. Accordingly, the temperature of the ink is controlled by one or more water cooled rollers as it is transferred through the inker assembly to the plate cylinder <NUM>. The chosen temperature set point may be chosen to achieve a desired ink viscosity.

Referring to <FIG>, a printing ink temperature regulation system <NUM> includes a recirculating chiller <NUM>; the rollers of the inker assembly <NUM>; a temperature sensor, such as an inline temperature sensor <NUM> in the coolant flow at the outlet <NUM> of the inker assembly <NUM>, a valve <NUM> for controlling the coolant flow, and a control system (not shown in the figures) that assesses the coolant outlet temperature and controls the position and movement of valve <NUM>. The pump <NUM> may be of any type, as will be understood by persons familiar with conventional cooling systems in view of the present disclosure. The flow from <NUM> pump may be controlled by any means. In one embodiment, a variable speed drive (such as a Variable Frequency Drive (VFD)) is employed and configured to maintain approximately constant coolant pressure, regardless of the position of the valve <NUM>. Other drives are contemplated.

The system <NUM> can be configured such that there is a temperature sensor <NUM> at the coolant outlet of each one of the inker assemblies <NUM>, the coolant outlet flows can be combined (as, for example, via a manifold) such that a single (that is, only one) temperature sensor is located in the combined stream, or the coolant streams from two or more inker assemblies can be combined such that the coolant flow is separated into zones. Each zone, in addition to having its own temperature sensor, can have its own pump and/or valve.

Preferably, oscillating roller assemblies 610u, 610a, and 610b, described more fully below, receive coolant from chiller <NUM>. For each assembly, coolant preferably flows through a center of each one of the oscillator shafts 612u, 612a, and 612b, and then counter-flows concentrically (either inside or outside the in-flow) through the same end of the roller assembly as the coolant inlet. Other configurations are contemplated.

Sensor <NUM> at the outlet <NUM> of the inker assembly <NUM> is on the inlet side of the chiller <NUM>. Thus, the valve <NUM> can increase coolant flow rate if the coolant outlet temperature at temperature sensor <NUM> is higher than a predetermined set point or range, and can decrease coolant flow rate if the coolant outlet temperature is lower than the predetermined set point or range.

A controller to actuate the valve <NUM> based on the temperature sensor <NUM> and other conventional inputs and data can be of any type using any algorithm or method, such as a PID control (that is, proportional integral derivative control) or other control, as will be understood by persons familiar with industrial equipment controllers.

The chiller <NUM> may be a stand-alone chiller that supplies coolant only to the inker assembly <NUM>, or may be a chiller or cooler that supplies coolant to other parts of the can decorating machinery or other plant equipment.

Each print cylinder <NUM> is supplied with a single color of ink by an inker assembly <NUM>. Accordingly, the number of inker assemblies <NUM> matches the number of print cylinder assemblies described herein.

Each inker assembly <NUM> for supplying ink to the plate cylinder <NUM> includes an ink well (also referred to as a fountain) <NUM> and a series of rollers mounted to a structural frame <NUM>. Ink well <NUM> can be of any type. The rollers transfer and smooth, and to some extent meter, ink from the ink well <NUM> to the plate cylinder <NUM>. Referring to <FIG>, within the inker assembly <NUM>, to promote uniform ink application, an oscillation roller assembly <NUM> may move an ink roller axially back and forth, as described more fully below.

Inker assembly <NUM>, in the embodiment shown in the figures, includes an oscillating roller assembly <NUM> that includes a single oscillating roller drive assembly <NUM> and three oscillating roller assemblies 611u, 611a, and 611b. Inker assembly <NUM> also includes distributor roller assemblies 660u, 660a, and 660b, and form roller assemblies 670a and 670b. As illustrated in the figures, a preferred embodiment system has a single oscillating roller drive assembly <NUM> to achieve oscillation of all three oscillating roller assemblies 611u, 611a, 611b.

Each oscillating roller assembly 611u, 611a, 611b includes an oscillating roller shaft <NUM> (or "oscillator shaft"), an oscillating roller body <NUM> (or "oscillator body"), a linear bearing <NUM>, and a support bearing assembly <NUM>. In some embodiments, bearing assembly <NUM> includes a lubrication supply gallery in which oil lubricant is supplied to the oscillator shaft support bearing <NUM> and recovered and managed through co-operation of a lubrication recovery housing <NUM> and the lubrication return gallery. Each bearing <NUM> and <NUM> is supported by frame <NUM>.

Each distributor roller assembly 660a and 660b includes a distributor roller shaft 662a and 662b, a distributor roller body 664a and 664b, and a gear 666a and 666b, respectively. Each form roller assembly 670a and 670b includes a form roller shaft 672a and 672b, a form roller body 674a and 674b, and a gear 676a and 676b, respectively. Rollers <NUM> and <NUM> are supported by bearings that are supported by frame <NUM>.

As is clear from the usage above, when there is more than one component, individual components (such as oscillating roller assemblies 611u, 611a, 611b) are identified by appending a letter a, b, or c. The components in general or as a group are referred to as reference number without an appended letter (such as by reference number <NUM> to refer to the oscillating roller assembly). This convention, referring to individual components by an appending a letter onto a reference number and using an un-appended reference number to refer to the components as a group or generally, may be used other places in this specification.

The inker assembly <NUM> can be separated into three zones: a drive zone <NUM>, an ink zone <NUM>, and operator zone <NUM>. The drive zone <NUM> is outboard of the inker assembly frame <NUM>, which preferably is an enclosure, on one side and the operator zone <NUM> is on the opposing side. The ink zone <NUM> is between the opposing plates of the frame <NUM> and includes the rollers.

As best illustrated in the <FIG> and <FIG>, the inker assembly <NUM> includes an upper oscillating roller 611u, left and right distributor rollers 660a and 660b. The bodies 664a and 664b of left and right distributor rollers 660a and 660b are engaged with the roller body 614u of upper oscillating roller 611u. The body of left and right oscillating rollers 610a and 610b are engaged with the corresponding left and right distributor rollers 660a and 660b. Left and right form rollers 970a and 970b are engaged with the corresponding left and right lower oscillating rollers 610a and 610b, and each one of the form rollers 670a and 670b engages the plate cylinder <NUM>.

Referring to <FIG>, each inker assembly also includes a fountain roller <NUM> located at ink well <NUM>, a ductor roller <NUM> adapted to engage the fountain roller <NUM>, a transfer roller <NUM> adapted to engage the ductor roller <NUM>, and an upper distributor roller 660u adapted to engage transfer roller <NUM> and to engage upper oscillating roller 611u. Rollers <NUM>, <NUM>, and <NUM> may employ conventional inker roller technology. For convenience in the description, roller assemblies <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> are referred to as "laterally-fixed roller assemblies" to distinguish them from the laterally oscillating roller assemblies <NUM>. The laterally-fixed roller assemblies can be conventional, and do not require and need not have special structure to maintain their lateral positions. Rather, the term "laterally fixed" is used merely to refer to conventional rollers that do not have a system to create lateral or oscillating motion of the roller for distributing ink.

In the embodiment shown in the figures, the oscillating roller assembly <NUM> includes a single oscillator drive assembly <NUM> that includes (preferably) a single cam drive gear <NUM> mounted on a cam body <NUM>. A cam <NUM> is formed in cam body <NUM> and preferably is a rise-and-fall or undulating continuous recess or groove about the circumference of cam body <NUM>. A cam gear or idler gear <NUM> is also mounted to cam body <NUM>. Cam body <NUM>, cam <NUM>, and idler gear <NUM> are mounted to a cam shaft (mounted to frame <NUM>) and constrained such that cam body <NUM>, cam <NUM>, and idler gear <NUM> rotate about a cam shaft center axis, identified as line CSA in <FIG>, as each one of elements <NUM>, <NUM>, and <NUM> are coincident or share the same centerlines.

The oscillator drive assembly <NUM> can be considered to include three cam follower supports 650u, 650a, 650b and three corresponding cam followers 652u, 652a, 652b, each of which is affixed or unitary with the corresponding cam follower support. Each cam follower 652u, 652a, 652b and associated cam follower support 650u, 650a, 650b are mounted on the corresponding oscillating roller shaft 612u, 612a, 612b and co-operate directly with the cam groove <NUM>. The cam follower supports are configurated to transmit "rise-and-fall" or "back-and-forth" translation to the corresponding oscillating roller body 614u, 614a, and 614b. Linear bearings 616u, 616a, 616b co-operate with the frame <NUM> to constrain the corresponding cam follower support 650u, 650a, 650b to linear motion.

As illustrated in the figures, three multiple oscillating roller assemblies 611u, 611a, 611b are arranged about the single oscillator cam body <NUM>. The oscillating roller assemblies 611u, 611a, 611b can be arranged equally spaced about a pitch circle diameter where the center point of the pitch circle diameter is coincident with the axis of a single oscillator cam body <NUM> and such that upper oscillating roller assembly 611u is the top center (that is, at the <NUM> o'clock relative to the centerline of cam body <NUM>), and roller assemblies 611a and 611b are spaced <NUM> degrees from upper roller assemblies 611u and from each other. Other configurations are contemplated.

Referring to <FIG>, each inker drive assembly includes a coupling <NUM> for receiving power from a motor (not shown) or through gearing connected to another power source (not shown). A first idler gear 692a is mounted on a common shaft with coupling <NUM>. First idler gear 692a is engaged (that is, in mesh contact so as to be capable of transmitting torque) with a drive gear <NUM> that is mounted on the shaft of transfer roller <NUM>. Transfer roller drive gear <NUM> is engaged with a second idler gear 692b, which at a lower level is engaged with a third idler gear 692c, which is engaged with fourth idler gear 692d, which is engage with fountain roller drive gear <NUM>.

The shaft on which third idler gear 692c is mounted has another gear, fourth idler gear 692d, mounted on an end thereof that is distal from third idler gear 692c. Fourth idler gear 692d engages a fifth transfer gear 692e, which engages a sixth transfer gear 692f, which engages the cam drive gear <NUM>.

The gears described herein for the inker system <NUM> may be conventional, such as conventional spur gears. The figures illustrate gear ratios, tandem gears (that is, two or more gears on one shaft), and other details of the gear train. Further, the gear ratio and gear designs may be chosen according to the desired parameters of the inking system. And other means for transmitting torque are possible. In this regard, the term "transmission" is used to refer to any means for transmitting torque, such as a gear train, belt and pulley system, sprocket assembly, and the like.

The present invention is not limited to any gearing configuration or even to gears at all, as (as explained above) alternatively, the gear system could be a pulley and belt system, or sprocket and chain system to achieve the functions as needed. Persons familiar with inker system structure and function will understand the design parameters to achieve the desired system function. Thus, the inker gear train illustrated and described herein is provided merely for convenience of illustration and is not intended to limit the scope of any invention disclosed herein unless expressly claimed.

Preferably each one of the support bearings 620u, 620a, and 620b of the oscillating roller assemblies <NUM> include a lubrication system that includes a housing <NUM>, a supply system <NUM> that feeds lubricant into an inlet plenum <NUM> formed in the housing <NUM>, a return system <NUM> for enabling discharge of lubricant from an outlet plenum <NUM>.

<FIG> show an enlarged view of the preferred embodiments of the support bearings 620u, 620a, and 620b. As illustrated in the figures, each one of the support bearings 620u, 620a, and 620b includes a two-part housing <NUM> (that is, 622u, 622a, and 622b) that forms an inlet plenum and an outlet plenum for holding lubricant and for enabling the lubricant to flow through the corresponding housing 622u, 622a, and 622b to lubricate bearing <NUM> (that is, bearing 632u, 632a, and 632b) therein. The two-part lubricant recovery housing 622u, 622a, and 622b includes a base <NUM> (that is, 616u, 619a, and 619b) and a cap <NUM> (that is, as illustrated 621a, 621b, and 621b).

For each bearing <NUM>, an inlet <NUM> (illustrated in <FIG>) connects a lubricant supply system to inlet plenum <NUM> and an outlet <NUM> (illustrated in <FIG> as outlets 631a and 631b) connects a lubricant return system to outlet plenum <NUM>. The particular configuration of the plenums <NUM> and <NUM> may be chosen according to the desired bearing type, size, rating, and other known parameters.

In the embodiment of the figures, each bearing base 622u, 622a, and 622b is affixed to frame <NUM>. The bearing cap 622u, 622a, and 622b includes slots for enabling angular positioning of the cap such that the circumferential position of corresponding outlet 631u, 631a, and 631b relative to a horizontal datum can be chosen and/or adjusted as needed. In some embodiments, the circumferential position of the outlet <NUM> will determine a depth of lubricant in the plenums <NUM> and <NUM>. Optionally, the position of the inlet <NUM> may also be circumferentially adjustable. The term "supply gallery" is used herein to refer to inlet <NUM> for receiving lubricant and inlet plenum <NUM>. The term "return plenum" is used herein to refer to outlet <NUM> and outlet plenum <NUM>. The particular structure and function of the supply gallery and return gallery illustrated are not intended to be limiting, but rather encompass other structures according to the plain meaning of the structural terms, and as set out in the claims.

The lubrication system can be a closed loop system that can include a pump, filter, cooler, instrumentation and controls, and other conventional oil conditioning equipment. The lubrication system components may be chosen according to design parameters well known in the art and depending on the particular configuration of the bearings <NUM> and other components of the oscillating roller assemblies <NUM>. Thus, lubricant is supplied to the oscillator shaft support bearings <NUM> through co-operation of the lubricant supply gallery and bearing housing. Lubricant supplied to the oscillator shaft support bearing is recovered and managed through co-operation of lubrication recovery housing and the lubrication return gallery. The lubricant is preferably an oil.

To illustrate the function of the structure of inker system <NUM> and to describe a method of operating an inker assembly, torque is supplied to the gear train by connection of a rotating shaft to coupling <NUM>, which transmits torque through the drive train to rotate fountain roller drive gear <NUM> and to rotate cam drive gear <NUM>. Optionally, third idler gear 692c may engage upper oscillating roller drive gear 654u.

As cam body <NUM> rotates about its longitudinal axis from torque applied via the cam drive gear <NUM>, the cam followers 652u, 652a, and 652b on each one of the oscillating roller assemblies 610u, 610a, and 610b engages the rotating cam <NUM>.

Referring to only one of the three oscillating roller assembly systems for illustration, as the description of the other rollers will be the same, the undulating path of the cam <NUM> causes the oscillating translation (fore and aft or back and forth) of the cam follower 652u, which motion is transmitted to the cam follower support 652u, which motion is in turn transmitted to the roller shaft and roller 612u. In this regard, oscillator shaft support bearing 620u and linear bearing 616u are fixed to the bearing housing <NUM> such that oscillating roller shaft 612u is supported and constrained by the oscillator shaft support bearings. The oscillating roller shaft 612u rotates and translates about its own axis to spread and even out the ink as it interacts with rollers above and below it to deliver to the plate cylinder. Oscillating roller assemblies 610a and 610b operate as describe for assembly 610u.

Other rollers, such as fountain roller <NUM>, ductor roller <NUM>, and transfer roller <NUM> can rotate independently from the linear motion of the oscillating rollers, either driven directly from the gear train of through contact with other rollers.

The inker configuration described herein has some advantages over prior art systems. The present invention is not limited to structures of functions embodying or including the advantages, unless expressly set out in the claims, nor are the advantages listed herein intended to distinguish the inventive structure or function. Rather, the advantages are merely for illustrations. The structure shown in the figures engages three oscillating roller systems, as prior art, pivoting lever-type configurations are often effectively limited to cooperation with no more than two oscillator shafts. Prior art cams and cam followers typically provided higher inertia, and the magnitude of the reaction force sum in configurations in which the cam is mounted directly on the oscillating roller shaft. The structure in the figures diminishes the magnitude of inertia compared with prior art oscillating roller structures. And dynamic loading on the cam and cam follower are reduced. Symmetric arrangement of multiple oscillating roller assemblies about a single cam combined with the "rise-fall-rise" cam profile sums complementary reaction forces to zero thereby eliminating a source of vibration and extending component life. And total loss lubrication systems can contaminate the ink zone and the operator zone. Current commercially available beverage can printing machinery rely on periodic operator intervention to manually wipe clean the total loss lubricant, which operator intervention is eliminated or diminished in the embodiment of the figures.

In many prior art machines, beverage can bodies exit the print region and enter the over-varnish unit on mandrels that are stationary (that is, not rotating about the longitudinal axis of the mandrel), or that have reduced rotational speed (compared with the rotations speed immediately after engaging the print blankets) due to friction. As used herein, the term "pre-spin" refers to imparting rotation to the beverage can body <NUM> about its longitudinal axis after dis-engaging with the print blanket <NUM> of the blanket drum assembly. For decorators without pre-spin of the mandrels before the over-varnish unit, rotation of the mandrel occurs instantaneously with contact between a mandrel drive tire and the mandrel, which is simultaneous with contact between the can body and over-varnish applicator roller. Thus, without pre-spin, accuracy of "can wraps" may be lost due to skidding between can body and over-varnish applicator roller.

Referring to prior art <FIG>, a prior art over-varnish unit <NUM> includes and over-varnish fountain well <NUM> that supplies a coating to a gravure roller <NUM> that supplies the coating an applicator roller <NUM>, that in turn applies the coating to the can bodies <NUM> on mandrels <NUM>. The mandrel wheel <NUM> is driven by a mandrel drive tire <NUM> that is driven by a drive belt (not shown in the figures). The belt, applicator roller <NUM>, and drive tire <NUM> are within a varnish unit enclosure <NUM>.

Varnish mist created by the over-varnish process and condensate from the mist can build up on the components, including the mandrel drive tire, which can transport varnish from within the over-varnish enclosure <NUM> into the general environment of the beverage can decorating machine print section. The contamination by varnish of the general machine environment leads to uneconomic consumption of varnish, loss of production for clean-up schedules, & possible quality issues.

Referring to the embodiment of illustrated in <FIG>, over-varnish unit <NUM> of decorator <NUM> includes and over-varnish fountain well <NUM> that supplies a coating to a gravure roller <NUM> that in turn supplies the coating to an applicator roller <NUM>, that in turn applies the coating to the can bodies <NUM> on mandrels <NUM>.

The mandrel wheel <NUM> and over-varnish unit <NUM> configuration provides independent support for a mandrel pre-spin system <NUM>, as it can be (optionally) supported by the machine frame <NUM>. In this embodiment, the over-varnish assembly <NUM> can be removed (such as for maintenance or repair) while the over-varnish pre-spin assembly <NUM> remains mounted on the beverage can decorator machine. Support of the pre-spin assembly <NUM> independent from the support of the over-varnish unit also enables a mandrel drive belt <NUM> to be exchanged without removing the over-varnish applicator roller <NUM>. Other embodiments protect some of the mandrel drive belt components from varnish mist and condensate.

Mandrel pre-spin drive <NUM> includes a motor (not shown in the figures), a motor shaft <NUM>, a drive pulley <NUM> mounted on shaft <NUM>, idler pulleys <NUM>, and a mandrel drive belt <NUM>. The mandrel drive belt <NUM> extends between the pulleys <NUM> and <NUM> and contacts mandrels <NUM>. In this regard, can bodies <NUM> after contact with blanket pads <NUM> are engaged by mandrel drive belt <NUM> just before the can bodies <NUM> engage the applicator roller <NUM> to impart rotation of the mandrel <NUM> on which the can body is loaded. This "pre-spin" of the mandrel and can body improves the engagement of the can body <NUM> with the applicator roller <NUM>.

As illustrated in <FIG> the pre-spin drive assembly <NUM> can be supported by the machine frame <NUM> (or supported by a separate, independent frame, not shown in the figures). The mandrel drive belt <NUM> and drive pulley <NUM> and idler pulleys <NUM> all outside of the over-varnish unit enclosure <NUM>. In the embodiment of the figures, belt <NUM> extends behind the applicator roller <NUM> and the rear wall of its enclosure <NUM>. Thus, the belt pulleys <NUM> and <NUM> and belt <NUM> are spaced apart from and at least partially, and preferably wholly, protected from varnish mist and by the over-varnish unit enclosure. The term "belt" as used herein relating to the pre-spin belt can encompasses other means, such a chain, gears, and the like.

Advantages to the pre-spin configuration shown and described herein also includes that the accuracy of "can wraps" is improved by the pre-spin because friction characteristics between the mandrel and mandrel drive belt are consistent. And mandrel rotational pre-spin speeds are independent of other drives in the beverage can decorating machine in embodiments in which the mandrel drive belt has its own motor.

Claim 1:
An inker assembly (<NUM>) of a can decorator, comprising:
an ink well (<NUM>);
plural laterally-fixed roller assemblies (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), each laterally-fixed roller assembly comprising a roller configured to rotate about an axis and having a fixed position along the axis;
plural oscillating roller assemblies (610u, 610a, 610b, 611u, 611a, 611b), each oscillating roller assembly including an oscillator body (614u, 614a, 614b), an oscillator shaft (612u, 612a, 612b) supporting the oscillator body, and a cam follower (652u, 652a, 652b) coupled to the oscillator shaft; the oscillating roller assemblies and the laterally-fixed roller assemblies configured for cooperation to transmit ink from the ink well to a plate cylinder (<NUM>) of the can decorator;
a cam body (<NUM>) having a cam (<NUM>) that is engaged with at least one of the cam followers of the oscillating roller assemblies; and
a cam drive transmission for rotating the cam body and cam;
characterised in that rotation of the cam body moves the at least one of the cam followers fore and aft, thereby moving the oscillator shaft and oscillator body fore and aft.