Inker Assembly Including Oscillation Rollers For A Can Body Decorator
1. An inker assembly of a can decorator, comprising:
- an ink well;
plural laterally-fixed roller assemblies;
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 adapted 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 cam followers fore and aft, thereby moving the oscillating roller fore and aft.
An oscillating roller system for a beverage can decorator is driven back and forth by a cam follower. A cam body having a cam is mounted to a frame of the inker system. Three oscillating cam roller assemblies are positioned about the cam body. Rotation of the cam oscillates the cam followers for each one of the oscillating rollers. Bearings of the oscillating roller assemblies includes an inlet gallery and outlet gallery for a closed loop lubrication system. The rollers are water cooled.
- 1. An inker assembly of a can decorator, comprising:
an ink well; plural laterally-fixed roller assemblies; 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 adapted 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 cam followers fore and aft, thereby moving the oscillating roller fore and aft.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- 13. An ink cooling system for inker assemblies of a can decorating machine, the ink cooling system comprising:
a recirculating chiller adapted for transferring heat from the ink to a coolant; a temperature sensor in a coolant outlet from the inker; and a valve adapted to control coolant flow rate in response to data from the temperature sensor to regulate ink temperature to a target temperature.
- View Dependent Claims (14, 15, 16, 17)
This application is related by subject matter to U.S. application Ser. No. ______, filed Oct. 31, 2019 (Attorney Docket Number 102070.006882) and to U.S. application Ser. No. ______, filed Oct. 31, 2019 (Attorney Docket Number 102070.006886); which claims priority to U.S. Patent Application Ser. No. 62/753,818, filed Oct. 31, 2018, the disclosure of the invention in which is hereby incorporated by reference as if set forth in its entirety herein.
The present inventions relate to printing equipment and methods, and more particularly to a beverage can decorator, including subsystems and methods relating to same.
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 3000 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, U.S. Pat. No. 5,337,659 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, 24 or 36 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 co-operates 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 360 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.
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.
According to an aspect of an embodiment of the present invention, an inker assembly of a can decorator can include: an ink well; plural laterally-fixed roller assemblies; plural oscillating roller assemblies; and a cam body. Each oscillating roller assembly can include 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 can be adapted for cooperation to transmit ink from the ink well to a plate cylinder of the can decorator. The cam body can include a cam that ca engage with at least one of the cam followers of the oscillating roller assemblies. Thus, rotation of the cam body moves the cam followers fore and aft, thereby moving the oscillating roller 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 adapted for water cooling.
The cam drive transmission can include a cam drive gear mounted on the cam body and a gear train adapted 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 lubricant supply gallery, a lubricant recovery housing, and a lubricant return gallery. A closed loop lubrication system can be adapted for supplying lubricant to the oscillating roller assembly support bearings and receiving lubricant from the oscillating roller assembly support bearings.
According to another aspect of an embodiment of the present invention, an ink cooling system for inker assemblies of a can decorating machine can include: a recirculating chiller adapted for transferring heat from the ink to a coolant; a temperature sensor in a coolant outlet from the inker; and a valve adapted 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 10 for printing text and graphics on can bodies, such as beverage can bodies 99, includes a structural frame 20; an infeed assembly 100; a print assembly 200; a color assembly 300 that includes a print registration system 400, a temperature regulation system 500, and an inker array 600; an over-varnish assembly 700; and a discharge assembly 900. Some subsystems of decorator 10 are illustrated in
Can bodies 99 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 99 handled by the infeed assembly 100 typically have an exterior that is uncoated aluminum, sometimes referred to as bright cans. It is anticipated that can bodies 99 are prepared for coating in decorator 10 by conventional preparation and handling techniques that are well known to persons familiar with decorating cans at commercial speeds, often over 1,000 cans per minute and approximately 2,200 cans per minute. Can decorator throughput is chosen to match the upstream and downstream processes such that 2,200 cans per minute is not a practical upper limit, as a modern decorator 10 can achieve greater throughputs (such as 3400 cans per minute) depending on many parameters.
Beverage can bodies 99 typically have a thin sidewall, such as below 0.010 inches thickness and often approximately 0.004 inches thickness for conventional 12 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 3000 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 202 (53 mm), 204.5 (58 mm), and 211 (66 mm) nominal (diameter) size; three piece cans of any commercial size; aerosol cans of 112 (45 mm), 214 (70 mm), and 300 (73 mm); open-top or seamed can bodies; aluminum, such as 3000 series aluminum alloy, tin plate, steel can bodies; and others.
Structural frame 20 includes a base 22 and a machine frame 30, which includes a planar rear face 32 and an opposing front face 34, as illustrated schematically in
Infeed turret 130′ rotates (counter-clockwise in the orientation shown in
The mandrel wheel assembly 210 includes a mandrel starwheel or mandrel wheel turret 220 and mandrel assemblies 228. Mandrel wheel turret 220 includes curve-cradle-shaped, peripheral recesses or pockets 222 that receive can bodies 99 from infeed system 100/100′. As turret 220 rotates about an axis defined by a mandrel wheel shaft 212, a vacuum is applied at each pocket 222 to retain the can body 99. The structure forming pocket 222 is not symmetrical about a radial line to enhance its ability to pick up can bodies 99, as is conventional.
In the embodiment illustrated in the figures, the mandrel wheel 210 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 304 are contemplated.
At commercial decorator speeds, loading the can bodies 99 onto the mandrels 230 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 222 are configured and spaced such that each pocket 222 aligns with a corresponding one of the mandrels 230, as illustrated in
Mandrel assembly 228 includes individual mandrels 230 and mandrel arm assemblies 240, which include mandrel trip assemblies 250. Mandrel assembly 228 rotates on shaft 212 in common with turret 220.
Mandrel arm assemblies 240, shown schematically in
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 10, 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 210 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 2000 can bodies per minute.
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 232 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 250 to avoid printing the surface of a misloaded mandrel 210 when no can body 99 is present. Trip mechanisms 250 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 99 are printed by engagement between the can bodies 99 and the print blankets 330. For accuracy, point D may be defined by the point of initial contact of the can body with the print blanket 330.
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 99 to be loaded onto the mandrel wheel 210. As explained below relative to the over-varnish unit, can bodies are discharged from mandrel wheel 210 to the discharge system 900.
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 2000 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 99 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 99 pass through the over-varnish unit after engagement with the print blanket 33, 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 160 to 200 degrees, is such that the decorator machine 10 can be suitable (as the inventors surmise) to run at high speed (approximately 2000 cpm), 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 160 degrees to 200 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 300 is supported by machine frame 20 and includes a main drive 304 (
Blanket wheel assembly 320 includes a horizontal main shaft 322 (indicated in relief in
Print cylinder assemblies 340 and inker assemblies 600 are housed or supported by machine frame 20 such that wheel 326 rotates relative to the print cylinder assemblies 340 and inker assemblies 600. Each inker assembly 600 of the array is associated with one color ink and each inker is associated with its own print cylinder assembly 340 such that each plate cylinder 350 can apply a single color to each print cylinder 350, which then transfers its single-color image to the rotating blanket 330. Each one of the plate cylinders 350 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 330. As blanket 330 contacts plate cylinder 350, plate cylinder 350 rotates approximately one revolution. The blankets and plate cylinder materials and structure can be conventional. In
As illustrated best in
Frame 30 includes the hollow, cylindrical print cylinder structural support 38 that extends inwardly from the front face 34. A print cylinder sleeve 346 is located within support 38 and is capable of movement relative to support 38. In the embodiment of the figures, sleeve 346 (as best shown in
A helical gear 316 is mounted on shaft 344 within housing frame 30 and aligned to engage main drive gear 312, which can be driven by main drive motor 306 and gearbox 308. During operation, main gear 312 drives shaft 344 through helical print cylinder gear 316, as shaft 344 rotation is supported by bearing 348 and internal bearings.
As explained above, while the can bodies 99 are on the mandrel wheel assembly 210, a can body is brought into contact with a blanket 330 of rotating blanket wheel 326 to transfer the ink from blanket 330 to the outer surface of the can body 99.
Can bodies 99, after contact with the printing blankets 330, receive an over-varnish from the over-varnish system 700. The cans exit the mandrel wheel assembly 210 after the over-varnish application when they are handed off to discharge assembly 900.
The print plates 350 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 330. Each one of the print plates 350 is registered with other ones of the print plates both axially (that is, longitudinal along axis of rotation of the plate cylinder 350 and can bodies 99) and circumferentially (that is, angularly relative to the rotation of the print blanket and can bodies 99).
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 424 and a circumferential print registration drive motor 462 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 442, which linear movement or displacement is transferred to the plate cylinder 350 through the print cylinder shaft 344. 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 316. Liner movement or displacement of helical gear 316 is converted to angular or circumferential movement or displacement of print cylinder shaft 344 (to which gear 316 is mounted) when pushed against stationary helical main gear 312, which circumferential movement or displacement is transferred to print cylinder 350 by print cylinder shaft 350.
As illustrated in
Referring again to
Circumferential print registration system 460 for each one of the printing plates or plate cylinders includes a circumferential registration drive 462, a circumferential registration shaft (also referred to as lead screw) 470 coupled to an output shaft of drive 462 via gears 490a and 490b or other transmission, a circumferential system slider 472, a circumferential system nut 474 that is affixed to slider 472 and in a threaded connection with lead screw 470, circumferential system linear bearings 476 in slider 472 for enabling slider 472 to translate on fixed support arms 40, a transfer arm 480, a hub 482 that is attached to slider 472 by transfer arm 480, and a key (not shown in the figures) for affixing a hub bore to driven gear 316. 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 462 can include a motor 464, a gearbox 466, and a housing 468 that is mounted to frame 30.
The axial and circumferential registration slide linear bearings 446 and 476 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 440 and 470 are constrained to the machine frame such that shafts 440 and 470 rotate but do not move axially.
The motors of drives 422 and 462 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 422 and the circumferential registration drive may be any type that can accurately and repeatably move or index axial registration slider 442 and circumferential slider 472, respectively, to desired position. The axial registration drive 422 and the circumferential registration drive 462 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 470 and axial registration lead screw 440 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 422 is coupled to an inline axial registration lead screw (or shaft) 440 that is coaxial and inside of the circumferential registration lead screw 470. Shaft 440 extends through the body of axial registration slider 442 and through axial registration system bearings 446, which preferably are conventional slide bearings. Shaft 440 extends through nut 444, which is fixed on slider 442, such that rotation of shaft 440 translates slider 442. 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 422 rotates axial registration shaft 440, which translates axial registration slider 442 forward or rearward relative to decorator 10 (or distally or proximally, respectively, relative to the axial drive 422) on support arms 40.
The circumferential registration drive 462 has a gear 490a mounted on an output shaft, shown as the bottom gear in
Any mechanism for moving the plate cylinder 350 based on the axial registration slide assembly 420 movement may be employed. And any mechanism for moving the plate cylinder 350 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 442 is affixed to a U-shaped, vertically oriented transfer plate 450. A pair of upstanding arms of transfer plate 450 are held to a rearward face of axial registration slider 442 by a pair of clamps 452. One clamp 452 is applied to a left arm of plate 450 and the other clamp 452 is applied to a right arm of plate 450. A lower portion of plate 450 is affixed to sleeve 346. A pair of cam screws 453 for holding the clamps 452 to transfer plate 450 can be eccentric or tapered such that the clamps 452 securely retains the transfer plate relative to the axial slider 442. Accordingly, forward or rearward movement of the axial registration slider 442 translates sleeve 346, which translates print cylinder shaft 344 and plate cylinder 350. Transfer plate 450 may be not affixed to sleeve 346 such that sleeve 346 (in some embodiments) may be free to move circumferentially with print cylinder shaft 344 during the circumferential registration system. Other structures, such as springs acting on print cylinder shaft 344 to urge the shaft 344 rearwardly against transfer plate 450, a mechanical connection between transfer plate 450 and sleeve 346 and/or print shaft 344, and the like, to enable movement of plate cylinder 350 in response to movement of axial registration slider 442 is contemplated.
In the embodiment illustrated in the figures, the circumferential registration mechanism 460 can include a mechanical connection between the circumferential registration slider 472 and hub 482, which includes bearings (not shown in the figures) between an inboard surface of hub 482 and plate cylinder shaft 344. Accordingly, print cylinder shaft 344 can rotate relative to hub 482, as a housing of hub 482 is attached to circumferential registration slider 472 by arm 480 (as best shown in
The hub 482, in this regard, is constrained to have only axial movement relative to the plate cylinder shaft 344, while a rotating, interior portion of hub 482 is keyed to plate cylinder shaft 344 by a longitudinal key (not shown in the figures). Driven gear 316 is also keyed and fixed to the plate cylinder shaft 344 via a key in a longitudinal keyway in the interior hub bore. In some embodiments, the key attachments between gear 316 and plate cylinder shaft 344 may be such that gear 316 may be longitudinally slidable relative to shaft 344 by a dimension sufficient to enable the circumferential registration without resulting in axial movement of the shaft 344.
Accordingly, rotary motion of the circumferential registration drive gears 490a and 490b causes rotation of the circumferential lead screw 470, which moves circumferential slider 472 forward or rearward by interaction with nut 474. The forward or rearward movement of circumferential slider 472 is transmitted to the housing of hub 482 via the support arm 480. Hub 482 translates forward or rearward (depending on the direction of translation of slider 472) relative to print cylinder shaft 344—that is, while hub 482 translates, the plate cylinder shaft 344 and the plate cylinder 350 do not translate (that is, do not move axially). Translation of hub 482 translates gear 316 relative to shaft 344. As illustrated in the figures, gear 316 is helical such that the helical teeth of gear 316 are in meshed contact with the helical teeth of main drive gear 312. Gear 312 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 316 relative to main gear 312, which during the registration process is not rotating or rotatable, creates an angular displacement or rotation of driven gear 316. Because gear 316 is rotationally fixed via the key, the movement of circumferential registration slider 472 and axial displacement of the hub 482 causes a shift in timing between the gear 316 and drive gear 312, and in this way rotates the print cylinder 350 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 400, a feedback system includes an axial registration proximity sensor 492 and a circumferential registration proximity sensor 494. Axial registration sensor 492 preferably is mounted on axial system slider 442, such as a front-facing portion of the slider 442. Circumferential system sensor 494 preferably is mounted on circumferential system slider 472, such as on a front-facing portion of the slider 472.
Sensors 492 and 494 may be of any suitable type that performs the feedback function described herein. Sensors 492 and 494 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 442, 472, but may also or alternatively be connected to the plate cylinder shaft assembly. Thus, rotary encoder type registration position sensors 496, if employed, may be connected to the axis common to the registration drive motors 432, 462 and/or and registration lead screws 440, 470, 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 400, 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 350 to be registered.
Upon determining the magnitude of circumferential movement desired for the first one of the print cylinders 350, the motor of circumferential registration drive 462 is engaged to rotate circumferential registration lead screw 470 to translate circumferential registration slider 472 on support arms 40. The magnitude of circumferential translation may be measured or sensed by circumferential registration sensor 494 if mounted on circumferential registration slider 472, hub 482, or other translating portion of circumferential registration system 460 and/or by sensor 496 associated with circumferential registration motor 462, axial registration lead screw 470, or other rotating part of axial registration system 460. As explained above, axial displacement of slider 472 is converted into circumferential displacement of print cylinder 350.
Upon determining the magnitude of axial movement desired for a first one of the print cylinders 350, the motor of axial drive 422 is engaged to rotate axial lead screw 440 to translate axial registration slider 442 on support arms 40. The translation of slider 442 is transmitted to the plate cylinder shaft 344. The magnitude of the axial translation can be measured or sensed by axial registration sensor 492 based on translation of the axial registration slider 442 and/or sensor 496 associated with axial registration motor 422, axial registration lead screw 440, or other rotating part of axial registration system 420. If any axial movement of print cylinder 350 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 350 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 350 in its axial and circumferential orientation is achieved, the desired magnitude of axial and circumferential adjustment of the second plate cylinder 350 may be performed according to the above method. Conventional controls systems and techniques may be employed. As needed, each one of the plate cylinders 350 may be registered by its own registration system 410, 460 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 600 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, according to an aspect of the invention, 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 350. The chosen temperature set point may be chosen to achieve a desired ink viscosity.
The system 510 can be configured such that there is a temperature sensor 530 at the coolant outlet of each one of the inker assemblies 600, 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 520. For each assembly, coolant preferably flows through a center of each one of the oscillating roller 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 530 at the outlet 599 of the inker assembly 600 is on the inlet side of the chiller 520. Thus, the valve 540 can increase coolant flow rate if the coolant outlet temperature at temperature sensor 530 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 540 based on the temperature sensor 530 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 520 may be a stand-alone chiller that supplies coolant only to the inker assembly 600, 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 350 is supplied with a single color of ink by an inker assembly 600. Accordingly, the number of inker assemblies 600 matches the number of print cylinder assemblies described herein.
Each inker assembly 600 for supplying ink to the plate cylinder 350 includes an ink well (also referred to as a fountain) 602 and a series of rollers mounted to a structural frame 604. Ink well 602 can be of any type. The rollers transfer and smooth, and to some extent meter, ink from the ink well 602 to the plate cylinder 350. Referring to
Inker assembly 600, in the embodiment shown in the figures, includes an oscillating roller assembly 610 that includes a single oscillating roller drive assembly 640 and three oscillating roller assemblies 611u, 611a, and 611b. Inker assembly 600 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 640 to achieve oscillation of all three oscillating roller assemblies 611u, 611a, 611b.
Each oscillating roller assembly 611u, 611a, 611b includes an oscillating roller shaft 612, an oscillating roller body 614, a linear bearing 616, and a support bearing assembly 620. In some embodiments, bearing assembly 620 includes a lubrication supply gallery in which oil lubricant is supplied to the oscillator shaft support bearing 620 and recovered and managed through co-operation of a lubrication recovery housing 622 and the lubrication return gallery. Each bearing 616 and 620 is supported by frame 604.
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 660 and 670 are supported by bearings that are supported by frame 604.
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 610 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 600 can be separated into three zones: a drive zone 605, an ink zone 606, and operator zone 607. The drive zone 605 is outboard of the inker assembly frame 604, which preferably is an enclosure, on one side and the operator zone 607 is on the opposing side. The ink zone 606 is between the opposing plates of the frame 604 and includes the rollers.
As best illustrated in the
In the embodiment shown in the figures, the oscillating roller assembly 610 includes a single oscillator drive assembly 640 that includes (preferably) a single cam drive gear 642 mounted on a cam body 644. A cam 646 is formed in cam body 644 and preferably is a rise-and-fall or undulating continuous recess or groove about the circumference of cam body 644. A cam gear or idler gear 648 is also mounted to cam body 644. Cam body 644, cam 646, and idler gear 648 are mounted to a cam shaft (mounted to frame 604) and constrained such that cam body 644, cam 646, and idler gear 648 rotate about a cam shaft center axis, identified as line CSA in
The oscillator drive assembly 640 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 646. The cam follower supports are configured 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 604 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 644. 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 644 and such that upper oscillating roller assembly 611u is the top center (that is, at the 12 o'"'"'clock relative to the centerline of cam body 644), and roller assemblies 611a and 611b are spaced 120 degrees from upper roller assemblies 611u and from each other. Other configurations are contemplated
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 642.
The gears described herein for the inker system 600 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 610 include a lubrication system that includes a housing 622, a supply system 624 that feeds lubricant into an inlet plenum 626 formed in the housing 622, a return system 628 for enabling discharge of lubricant from an outlet plenum 630.
For each bearing 620, an inlet 625 (illustrated in
In the embodiment of the figures, each bearing base 622u, 622a, and 622b is affixed to frame 604. 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 631 will determine a depth of lubricant in the plenums 626 and 630. Optionally, the position of the inlet 625 may also be circumferentially adjustable. The term “supply gallery” is used herein to refer to inlet 625 for receiving lubricant and inlet plenum 626. The term “return plenum” is used herein to refer to outlet 631 and outlet plenum 630. 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 620 and other components of the oscillating roller assemblies 610. Thus, lubricant is supplied to the oscillator shaft support bearings 620 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 600 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 691, which transmits torque through the drive train to rotate fountain roller drive gear 681 and to rotate cam drive gear 642. Optionally, third idler gear 692c may engage upper oscillating roller drive gear 654u.
As cam body 644 rotates about its longitudinal axis from torque applied via the cam drive gear 642, the cam followers 652u, 652a, and 652b on each one of the oscillating roller assemblies 610u, 610a, and 610b engages the rotating cam 646.
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 646 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 604 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 680, ductor roller 682, and transfer roller 684 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 99 about its longitudinal axis after dis-engaging with the print blanket 330 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
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 1290 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
The mandrel wheel 210 and over-varnish unit 700 configuration provides independent support for a mandrel pre-spin system 270, as it can be (optionally) supported by the machine frame 30. In this embodiment, the over-varnish assembly 700 can be removed (such as for maintenance or repair) while the over-varnish pre-spin assembly 270 remains mounted on the beverage can decorator machine. Support of the pre-spin assembly 270 independent from the support of the over-varnish unit also enables a mandrel drive belt 224 to be exchanged without removing the over-varnish applicator roller 208. Other embodiments protect some of the mandrel drive belt components from varnish mist and condensate.
Mandrel pre-spin drive 270 includes a motor (not shown in the figures), a motor shaft 271, a drive pulley 274 mounted on shaft 271, idler pulleys 276, and a mandrel drive belt 272. The mandrel drive belt 272 extends between the pulleys 274 and 276 and contacts mandrels 280. In this regard, can bodies 99 after contact with blanket pads 330 are engaged by mandrel drive belt 272 just before the can bodies 99 engage the applicator roller 208 to impart rotation of the mandrel 280 on which the can body is loaded. This “pre-spin” of the mandrel and can body improves the engagement of the can body 99 with the applicator roller 208.
As illustrated in
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.
After the can bodies 99 have been coated in the over-varnish unit 700, the can bodies are transferred to a rotating can transfer assembly 902 and to a pin chain conveyor 904. In the embodiment of the figures, can bodies 99 exit from mandrel wheel 210 before the trip reset point E, but other configurations and sequences are contemplated. A mandrel brake (not shown) may stop the spinning of mandrel 280 before being in a position to receive a can body at point A.
The structure and function of features of a can decorator are disclosed and explained herein to illustrate inventive aspects of the decorator and its components. Further, several advantages of structures and functions are explained above. As partially explained above, the invention is not limited to any particular structure and/or function of the embodiments disclosed herein, nor is invention limited to any structure or functions having any of the advantages described herein. Rather, the structure and function and advantages in the text and drawings are merely to illustrate, and is not intended to limit the scope of the inventions. It is intended that the claims be given their fair and broad scope.