Patent Description:
In the field of consumer fluid container manufacture, customers typically require the containers to be decorated with source-identifying indicia, content information, nutritional data, recycling instructions, etc. Specialist printing apparatuses are known to provide continuous, mass printing onto containers at a high throughput. These printing machines are commonly known as "decorators" in the art. <CIT> discloses a decorator for printing onto cylindrical structures comprising a plurality of inkers.

At the present time, there are two main decorator designs which are in common commercial use, although there are additional, smaller volume manufacturers as well. The two main designs are commonly known as the "Concord" and "Rutherford" machines. Although the precise constructional details of the Concord and Rutherford machines differ, in essence they use the same approach to printing onto containers. This approach is a variant of offset printing. More specifically, the decorators comprise a plurality of inkers. Each inker is associated with a different color and has a printing plate affixed to a printing plate cylinder for that color. Each inker is configured to distribute ink of the correct color onto the printing plate. The printing plate has a raised portion corresponding to the desired image for the particular color in question. It will be apparent that, for example, a six inker decorator apparatus can print six colors, and an eight inker decorating apparatus can print eight colors.

The ink from the printing plate of each inker is transferred onto the surface of one of a number of transfer blankets. The intention is that the transfer blanket and the printing plate cylinders of all of the inkers are mutually positioned and oriented such that the different colored inks are in proper registration when applied on a transfer blanket and subsequently to a container. When proper registration is achieved, the pattern of multiple colored inks on the transfer blanket corresponds to the desired final decoration.

The decorator apparatus comprises a plurality of transfer blankets which are disposed on a rotating blanket wheel. As the wheel rotates, a transfer blanket which has had all of the inks transferred to it in the desired pattern is brought into contact with a container carried by a suitable conveyor system which typically uses a number of mandrels on a mandrel carrier. The decorator apparatus is configured so that each container is brought into contact with a transfer blanket so that the full multicolored indicia is transferred to the surface of the container.

During a continuous container printing process, some misregistration of one or more of the colors typically occurs. Misregistration is when designs are not properly positioned on the decorated container. Traditionally, registration errors have been corrected manually.

More specifically, misregistration is detected by manual inspection or non-manual inspection of the printed containers. If a misregistration is identified, it has been necessary to shut down printing for a period of time while manual adjustments of the inkers are made. This is an inefficient process for at least two reasons. First, there is a time lag before a misregistration is identified which can result in a large number of defective containers. Secondly, it is inefficient and undesirable to shut down a continuous process for any period of time.

The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior systems of this type. Additionally, the present invention provides improved arrangements for controlling the position of the printing plate cylinders. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.

The invention is defined in the independent claim <NUM> on file.

Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings.

To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:.

One embodiment of the present disclosure is directed to a retrofit of a container decorator, for example a Rutherford decorator inker. The retrofit comprises a servomotor drive. The servomotor drive is configured to allow independent control over an inker motion of the decorator. This is achieved by a servomotor separating the inker motion from an existing drive system of the decorator.

The existing drive system of the decorator includes a helical bull gear which drives a matching helical gear on each individual inker. By disconnecting the inker from the bull gear. A printing plate cylinder will become free spinning. This will allow a servomotor to be connected to the inker's gearbox and be driven independently. A servomotor will be synchronized with the decorator drive to ensure the servomotor is rotating the inker at the exact speed needed. The servomotor drive will be retrofitted with an encoder for positioning purposes. This will allow the servo to change its position of the printing plate cylinder while running to adjust for circumferential register positioning for that printing plate.

There are two registration adjustments on a prior Rutherford decorator, lateral and circumferential. These adjustments require the decorator to stop in order to make changes to the printing plate cylinder. By having a servomotor drive the inker, the position of the printing plate cylinder can be controlled independently from the rest of the decorator. This will allow an operator, through a human-machine interface (HMI) controller, to change a position of the servomotor thus changing the position of the printing plate cylinder rotational position. By having control of the rotational position of the printing plate cylinder, an operator can change the circumferential register of a printing plate while the decorator is operational and decorating containers.

Commercial decorators, such as a Rutherford decorator, require the apparatus to be stopped to make register adjustments. There are two possible register moves, lateral and circumferential. A servomotor driven inker will allow the adjustment of circumferential register without stopping the decorator, essentially minimizing graphic label change time by limiting the need to stop the decorator to make adjustment by half.

Thus, this disclosure describes corrections to a placement or location of a graphic on a container body, generally a cylindrical container body. Two types of corrections are described.

One type of correction is to the placement about the circumference of the container body. This type of correction may be referred to as left to right, angular, or circumferential corrections. This type of correction is generally accomplished by making small incremental adjustments to the position of a printing plate by rotating the printing plate, either clockwise or counterclockwise, relative to a transfer blanket on which the printing plate deposits ink in a desired graphic or shape. Thus, when viewing the decorated container body in normal upright use, these corrections would adjust the graphic an angle ϕ from a polar axis a cylindrical coordinate system.

The other type of correction is to the placement from one end of the container body to another end of the container body. This type of correction may be referred to as up and down, lateral, or linear corrections. This type of correction is generally accomplished by making small incremental adjustments to the position of a printing plate by moving the printing plate in a direction parallel to an axis of rotation of the printing plate cylinder shaft, relative to a transfer blanket on which the printing plate deposits ink in a desired graphic or shape. Thus, when viewing the decorated container body in normal upright use, these corrections would adjust the graphic upwardly or downwardly along an L-axis in a cylindrical coordinate system.

Generally, a decorator prints images on a metallic container, for example an aluminum beverage can. Within the decorator, there are <NUM> to <NUM> inkers which apply individual ink colors required for a finished graphic design. An inker transfers metered ink from an ink fountain through a series of rollers to apply a layer of ink on a raised image of a printing plate which is carried on a rotational printing plate cylinder. This method of printing is called flexography.

An additional step is performed by transferring an image representing a partial portion of the finished graphic design from a first printing plate to a transfer blanket, typically a rubber sheet member. This is repeated for as many printing plates, as necessary. For example, each printing plate of the <NUM> to <NUM> (or more, or fewer) printing plates transfers its respective pattern of ink to a single transfer blanket. In other words, each transfer blanket can receive ink from multiple printing plates.

After each transfer blanket receives ink from one or more printing plates. A single transfer blanket engages a single container to transfer a complete finished graphic design on the container. This extra step is referred to as "offset" and allows all the colored images from all the inkers to be applied to a single transfer blanket and then transferred to a single container.

The transfer blanket sheets are attached to a blanket wheel which is segmented to allow up to <NUM> transfer blankets to be attached thereto. As the blanket wheel rotates each transfer blanket collects the images from each printing plate and transfers all the images at once onto a container.

Each inker is fixed to the decorator housing and its rotation is controlled by one central motor which drives all the inkers and the blanket wheel at the same speed, this ensures a transfer blanket will receive an image from each printing plate at the correct time ensuring the image is lined up, i.e. in register.

Attached to the blanket wheel is a bull gear. This is a wheel with a helical gear attached to the outside diameter. When an inker is installed, the teeth of this bull gear line up with a helical gear attached internally in the inker. Each inker uses the same process of installation. Thus, when the bull gear is rotated each inker is rotated at the same rate causing the entire system to stay in time.

An inker has a series of rollers used to evenly distribute ink from an ink fountain to a printing plate carried on a printing plate cylinder. A printing plate cylinder shaft is rotated by a gear fixed to the shaft. This gear is matched to the bull gear. The printing plate cylinder shaft has a second gear attached to it. This second gear is used to drive all the rollers in the inker which also have a gear attached to them.

With the whole system in place, a motor drives the blanket wheel along with the bull gear. The bull gear drives each inker's printing plate cylinder shaft which in turn drives the roller train within each inker.

The printing plate cylinder shaft secures a printing plate cylinder. The printing plate cylinder is a component which holds the printing plate. The printing plate cylinder is magnetized, so a metal-backed printing plate is held in place. There are pins on the printing plate cylinder used to line up the printing plate which have punch holes matching the pins.

Misregistration often begins or originates during the installation of a printing plate on a printing plate cylinder and/or the printing plate cylinder on the printing plate cylinder shaft. A great area of concern is the printing plate mounted on the printing plate cylinder. With age, the printing plate cylinder pins can become worn causing the printing plate to be in a slightly different position with every install. Additionally, when the printing plate is made, there is always a chance of the machine not lining up the printing plate exactly perfect every time.

With these variables affecting each printing plate of each inker, there is a high probability that all or some of the final graphic design image will be out of register slightly on the container. There are adjustments in place to allow for manipulating the printing plate on each inker. On a Rutherford decorator, the process of making these adjustments requires the decorator to be stopped as the actual printing plate cylinder will need to be adjusted. Stopping a decorator is problematic during a printing plate adjustment as it is time-loss in production.

Again, there are two types of register issues which can be corrected by adjusting the printing plate cylinder, lateral and circumferential. Lateral register adjusts the image top to bottom of the container. Circumferential register alters the image position around or about a circumference of the container (which can also be considered as left to right or side-to-side).

Principles of the present disclosure enable circumferential register control remotely by individually driving the inker. This is accomplished by disconnecting the gear on the printing plate cylinder shaft from the bull gear allowing the printing plate shaft to be free spinning, then retrofitting a servomotor in operable engagement with the printing plate cylinder shaft. By using the existing gear train within the inker used to simultaneously drive all the rollers, a mounted servomotor drives that same roller train and the printing plate cylinder shaft. A servomotor with an accompanying encoder rotates the entire roller train.

The encoder ensures the servomotor is maintained at a same speed, or approximately the same speed, as the rest of the decorator by matching the speed with the decorator electronics. The encoder is electrically connected to the servomotor also allows the servomotor to change its position slightly while it is rotating by redefining the encoder position. This ability allows the inker's roller train to be repositioned rotationally. Since the printing plate cylinder shaft is part of the roller gear train, repositioning the roller gear train ultimately repositions printing plate cylinder and the image being transferred to the transfer blanket. This changes circumferential register. By having the ability to alter the circumferential register while the decorator is printing containers, downtime incurred during a graphic design change to correct register is reduced by <NUM>%, while downtime to solely correct registration errors can be reduced by as much as <NUM>% or more.

An existing inker must be modified to hold and support the servomotor, this requires one or more guards altered to fit a motor assembly. A software routine matches the resultant speed of the inker from the servomotor speed to the decorator speed. An HMI is incorporated in order to make changes to the servomotor to alter, change, or control register.

Generally, one aspect of the disclosure requires disconnecting a gear on the printing plate cylinder shaft from the bull gear which allows the printing plate cylinder to be free spinning, then retrofit a servomotor on the inker. By using the existing gear train within the inker used to simultaneously drive all the rollers, a mounted servomotor drives that same roller train and the printing plate cylinder shaft. A servomotor with an accompanying encoder drives the entire inker to cause rotation of the rollers, gears, and shafts of the inker. The encoder is a sensor that notifies a controller of a speed and a position of the servomotor. These encoders (position detectors) can be structurally classified as "incremental encoders" and "absolute encoders". An absolute encoder outputs the absolute position of a rotation angle. An incremental encoder outputs a pulse with respect to a change portion of a rotation angle.

The encoder ensures the servomotor maintained the same speed as the rest of the decorator by matching the speed with the decorator electronics. The encoder on the servomotor would also allow the servomotor to change its position slightly while rotating by redefining the encoder position. Stated another way, the servomotor changes the position of the printing plate relative to the transfer blankets and blanket wheel. The encoder measures that change. This ability would allow the inker's roller train to be repositioned rotationally. Since the printing plate cylinder shaft is part of the ink roller gear train, repositioning the roller gear train would ultimately reposition printing plate cylinder and the image being transferred to the blanket, this changes circumferential register. A human machine interface ("HMI") will be incorporated in order to make changes to the servomotor which will change register.

By modifying the main shaft on the inker, when the inker is mounting into the decorator it will have the ability to slide side-to-side while maintaining radial rigidity. The decorator has machined saddles the main shaft fits into, this main shaft is configured to allow the main shaft to move even when strapped in place. The straps ensure the inker will not move up or down but are configured to allow the main shaft to move axially. This axial motion will permit lateral registration.

Referring to <FIG>, a standard container decorator <NUM> is illustrated. This decorator <NUM> has one or more inkers 12a-12f (collectively referred to hereinafter as "<NUM>"). In the example illustrated, there are six (<NUM>) inkers which can supply six (<NUM>) different colored inks if desired. More or fewer inkers <NUM> can be employed on the decorator as a particular finished graphic design requires.

One or more, transfer blankets 14a-<NUM> (collectively referred to hereinafter as "<NUM>" and the transfer blanket which would be labeled "<NUM>" is otherwise obscured by decorator elements) are disposed on a blanket wheel <NUM>. A rotation by the blanket wheel <NUM> brings the transfer blankets <NUM> into contact with the inkers <NUM> to transfer ink onto the transfer blankets <NUM>. The rotation by the blanket wheel <NUM> also brings each transfer blanket 14a-h into contact with a container body <NUM> to transfer the ink onto a surface of the container body <NUM>.

The container bodies <NUM> on a mandrel carrier <NUM> are transported into and out of contact with the transfer blankets <NUM> by a conveyor system <NUM>.

In the embodiment shown in <FIG>, there are six inkers 12a-12f which enables up to six different color inks to be used to form the complete indicia which is printed onto each container <NUM>. Also, according to the embodiment shown in <FIG>, the decorator <NUM> comprises eight transfer blankets 14a-<NUM>. However, the invention is not limited in this regard, and in principle any suitable numbers of inkers and transfer blankets might be utilized.

The design and operation of the transfer blankets 14a-<NUM>, blanket wheel <NUM>, and conveyor system <NUM> with the mandrel carrier <NUM> are essentially conventional in nature. One of ordinary skill in the art is readily familiar with the general design and operation of same. Therefore, it is not necessary to provide a further, more detailed discussion of these portions of the decorator apparatus <NUM>.

Each inker <NUM> comprises a printing plate cylinder <NUM> which is rotated by a printing plate cylinder shaft <NUM>. These aspects of the inkers are described in more detail below. Other features of the inkers <NUM>, such as the arrangement for applying ink to the printing plate cylinders <NUM>, are essentially conventional in nature. Therefore, a more detailed discussion of these portions of the inkers <NUM> is not necessary. The decorator <NUM> or a decorating system comprises the decorator <NUM> and a controller device <NUM>.

The printing plate cylinder <NUM> has a printing plate <NUM> (see <FIG> and <FIG>) disposed thereon. One or both of the printing plate cylinder <NUM> and the printing plate <NUM> may be magnetic wherein that the printing plate <NUM> is attracted to be retained to the printing plate cylinder <NUM>.

Each printing plate <NUM> has raised features which correspond to the print pattern for the ink color which is applied by the particular inker 12a-12f to or with which the printing plate cylinder <NUM> is associated.

Generally, according to <FIG> and <FIG>, each inker unit <NUM> is removably secured to a main frame of the decorator <NUM> by a strap <NUM> (see, e.g., <FIG>) in clamping engagement with an outboard extension of a main shaft <NUM> at a bottom (i.e., in use, a portion of the inker <NUM> adjacent the blanket wheel <NUM> which carries rotationally carries the transfer blankets <NUM>) of each inker unit <NUM>. The main shaft <NUM> is transverse to vertical opposing frame plates <NUM>, <NUM>, <NUM> that are maintained in operable spaced relationship by additional transverse upper stiffening shafts <NUM>, <NUM>. Stiffening shaft <NUM> extends between frame plates <NUM>, <NUM>, and Stiffening shaft <NUM> extends between frame plates <NUM>, <NUM>.

A pair of rubber form rolls <NUM>, <NUM> is rotatably mounted in the space between frame plates <NUM>, <NUM> and engaged with plate cylinder <NUM> and an axially vibrated steel roll <NUM>. A steel roll <NUM> is engaged by a rubber-covered distribution roll <NUM>, which is engaged with an axially vibrated steel distributing roll <NUM> that is also engaged by two additional rubber-coated distribution rolls <NUM>, <NUM>. Distribution roll <NUM> also engages a steel roll (obscured) carried by shaft <NUM> (see, e.g., <FIG>) that is engaged with a rubber ductor roll <NUM>. The ductor roll <NUM> is also engaged with a steel fountain roll (obscured) carried by shaft <NUM> that combine with other known elements to form boundaries for an ink pool. These rolls will be hereinafter referred to collectively as the inker rolls. For purposes of this disclosure, the distribution rolls of each inker <NUM> act as a supply of colored fluid, such as ink, for each printing plate <NUM> in the inker <NUM> wherein a portion of the printing plate <NUM> in high relief receives the colored fluid from a supply of colored fluid, in this case the distribution rolls.

In a prior art inker, these inker rolls are positively driven through gears of a drive train <NUM> engaged with gears housed in a gear box <NUM> (see, e.g., <FIG>) that are keyed to the printing plate cylinder shaft <NUM> for the printing plate cylinder <NUM>. A drive gear <NUM>, keyed to the printing plate cylinder shaft <NUM>, is in operable engagement with a bull gear <NUM> of the blanket wheel <NUM>, which drives rotation of the inker rolls. Printing plate cylinder shaft <NUM>, as well as shafts <NUM>, <NUM>, <NUM>, and <NUM> for the respective rolls <NUM>, <NUM>, the obscured steel roll, and the fountain roll, extends through the frame plates <NUM> and <NUM>, and drive gear <NUM> is disposed between frame plates <NUM> and <NUM>.

However, according to one aspect of the present disclosure, the inkers <NUM> are outfitted, or an existing inker is retrofitted, with one or more servomotors, which drives the drive train within the gear box <NUM> (see, e.g., <FIG>).

According to an embodiment of the disclosure, as illustrated in, for example, <FIG> and <FIG>, drive gear <NUM> is disengaged from the bull gear <NUM>. As illustrated in <FIG> and <FIG>, the drive gear <NUM> is removed altogether. Thus, the printing plate cylinder shaft <NUM> is freewheeling relative to the bull gear <NUM>. An end of the printing plate cylinder shaft <NUM> distal from the printing plate cylinder <NUM> extends from the gear box <NUM> and is connected to a servomotor <NUM>. The servomotor <NUM> is a rotational or angular adjustment servomotor, and in this way, drives rotation of the printing plate cylinder shaft <NUM> which, in turn, drives rotation of the shafts <NUM>, <NUM>, <NUM>, and <NUM> via standard gearing within the gear box <NUM>.

It will be appreciated that the servomotor <NUM> is able to adjust an angular position of the printing plate cylinder <NUM>. That is the register associated with the circumference of the container.

Again, the servomotor <NUM> drives rotation of the printing plate cylinder shaft <NUM> and, by using the existing gears within the gear box <NUM>, to simultaneously drive all the inker rolls within the inkers <NUM>. Thus, a retrofit of the inkers <NUM> with the servomotor <NUM> drives rotation of the prior art inker rolls along with the printing plate cylinder shaft <NUM>.

The servomotor <NUM> with an accompanying encoder <NUM> drives the gears in the gear box <NUM>. The encoder <NUM> ensures the servomotor <NUM> maintains the same speed as the rest of the components of decorator <NUM> by timing the printing plate cylinder shaft <NUM> rotational speed with the decorator electronics.

The encoder <NUM> on the servomotor <NUM> also allows the servomotor <NUM> to change the position of the printing plate <NUM> relative to the blanket cylinder, slightly while rotating, by redefining the encoder position a few thousandths of an inch at a time. This ability would allow the inker rolls, including the printing plate cylinder shaft <NUM> carrying the printing plate cylinder <NUM> and the printing plate <NUM> to be repositioned rotationally. Since the printing plate cylinder shaft <NUM> is part of the inker gear train, repositioning the inker roll gear train would ultimately reposition the printing plate cylinder <NUM> and the printing plate <NUM> carried on the printing plate cylinder <NUM>. Thus, a register of an image transferred to the transfer blanket <NUM> can be controlled with adjustments by the servomotor <NUM>. This changes circumferential register or left and right register on an upright container.

An HMI is incorporated in order to make changes to the servomotor <NUM> which will change register.

According to an aspect of the present disclosure, each inker <NUM> is outfitted with one or more servomotors <NUM>. The servomotor <NUM> is provided to modify or change registry of the printing plate <NUM> in a longitudinal direction (i.e. a lateral adjustment servomotor). The longitudinal direction corresponds to a direction within manufacturing tolerances parallel to an axis of rotation of the printing plate cylinder shaft <NUM>. Thus, this configuration addresses top to bottom register of an image on an upright container.

To achieve automatic longitudinal register, the main shaft <NUM> on the inkers <NUM> is machined to allow the inker frame plates <NUM>, <NUM>, <NUM> to traverse on the main shaft <NUM> and along a direction of a center axis of the main shaft <NUM>. Bushings can be provided to facilitate the movement of the inker frame plates <NUM>, <NUM>, <NUM> on the main shaft <NUM>. This configuration allows the inkers <NUM> to slide side-to-side while maintaining radial inker rigidity.

The decorator <NUM> includes saddles <NUM>, for example, generally u-shaped support surfaces upon which the main shaft <NUM> is supported (see <FIG>, <FIG>, and <FIG>). The main shaft <NUM> fits/sits through/on the saddles <NUM>. The main shaft <NUM> and/or the saddles <NUM> are altered to allow the main shaft <NUM> to move even when clamped by the strap <NUM>. The straps <NUM> ensure that the inkers <NUM> will not move up or down but allow the inker <NUM> to move parallel to an axis of rotation of the printing plate cylinder shaft <NUM>. This axial motion permits lateral registration.

The servomotors <NUM> are positioned to act on the inkers <NUM>. These can be lineartype servomotors that push and/or pull the inkers <NUM> such that a printing plate position relative to the transfer blankets <NUM> can be altered. As illustrated in, for example, <FIG> and <FIG>, the servomotors <NUM> act on the outermost inker frame plates <NUM>, <NUM>. This arrangement can be modified to achieve the best result of the desired side-to-side movement parallel to the axis of rotation of the printing plate cylinder shaft <NUM>. The servomotors <NUM> can be supported against or by the decorator <NUM> external to the inkers <NUM> to provide the necessary opposite force which allows movement of the inkers <NUM> on their respective main shafts <NUM>. The same result might be obtained using rotating servomotors and a screw mechanism.

The present disclosure also includes a decorator <NUM> in combination with a controller <NUM>. The controller <NUM> combine with the modified inkers <NUM>, servomotors <NUM>, <NUM>, and the decorator <NUM> to form a decorating system that is includes a capability of manually and/or automatically adjusting image alignment of decorated containers "on the fly" or during a production run without appreciably adversely affecting production rate or speed, at the very least, without having to cease the decorating operation to make changes to the register/alignment of the image on the containers. The controller <NUM> includes a memory and software stored on the memory to regulate the inkers, for example the servomotors <NUM>, <NUM> on the inkers <NUM>.

Any of the known decorating inspection modules <NUM> can be used in the controller. Some of these inspection modules <NUM> are described in a non-limiting way, for example, in <CIT>. This is not intended to be an exhaustive list of the possible inspection modules that can be incorporated into this system and are set forth in this disclosure for illustrative example purposes.

Referring back to <FIG>, <FIG>, and <FIG>, the controller comprises an HMI <NUM> in communication with a standard programmable motion controller <NUM>, and amplifier <NUM>, the servomotors <NUM>, <NUM>, the decorator <NUM> and inkers <NUM>, and the inspection module <NUM>. One or more feedback circuits sends information from the servomotors <NUM>, <NUM> and the inspection module <NUM> to the programmable motion controller <NUM> and/or the HMI <NUM>. The HMI <NUM> acts as a system control, which in one possible mode of operation enables a user to make corrections manually. However, in another mode of operation, the controller <NUM> provides an automatic correction of any misregistration of the inks applied by one of more of the inkers <NUM> by receiving data from the inspection module <NUM>.

The controller <NUM>, again, includes a memory and utilizes a suitable computer program stored in the memory to react to the results obtained by the inspection module <NUM>. The inspection module <NUM> utilizes a suitable technique for recognizing misregistrations, such as, but not limited to, an optical device, for example, an imager or camera.

The controller <NUM> and its computer program is also adapted to provide suitable control signals to one or both of the servomotors <NUM>, <NUM> of an inker <NUM> in order to correct the detected misregistration. For example, if a misregistration was detected, and it was identified that the cause was that the image applied to the transfer blanket <NUM> by a particular inker in the plurality of inkers <NUM> was too high, then the longitudinal position of the printing plate cylinder <NUM> used in the inker would be modified to correct this misregistration. This would be done by controlling the servomotor <NUM> associated with main shaft <NUM> of the inker <NUM> so as displace the inker <NUM> along the main shaft <NUM>.

Another type of misregistration occurs when one of the ink colors is applied too far to the left or right on a container, i.e. misaligned about the circumference of the container. In this instance, the controller <NUM> or operator identifies which inker <NUM> is responsible for the misregistration and controls the servomotor <NUM> associated with this inker <NUM> to adjust the angular or rotational position of the printing plate <NUM>. In this way, the angular orientation of the printing plate cylinder <NUM> is adjusted so as to correct the misregistration.

It should be understood that if the controller or operator detects that a number of inks are being applied out of register, then appropriate correction of a plurality of inkers will occur. Likewise, misregistration can occur simultaneously laterally and circumferentially. In which case, the servomotors <NUM>, <NUM> would be activated to adjust the printing plate <NUM> laterally and circumferentially.

Another aspect of the disclosure is illustrated in <FIG>, in these embodiments, rotation of the printing plate cylinder <NUM> is driven by an angular adjustment servomotor <NUM>. The remaining gears of the drive train <NUM> remain indirectly driven by a bull gear <NUM>, as in the prior art. Thus, the printing plate cylinder <NUM> rotates independently of the remaining rolls of the inker <NUM>. This is accomplished by providing a two-part shaft <NUM> which comprises the printing plate cylinder shaft <NUM> located within a drive train shaft <NUM>. Accordingly, the two-part shaft <NUM> comprises two shaft components, an inner printing plate cylinder shaft <NUM> and an outer drive train shaft <NUM>.

In this embodiment, the servomotors <NUM>, <NUM> are fixedly attached to the decorator frame and are generally not removable with the inkers <NUM>. That is to say, the inkers <NUM> are removable to swap out designs and are disconnected from and operably joined to the servomotors <NUM>, <NUM> during such exchanges, retrofits, modifications or upgrades. This differs from the embodiments illustrated in <FIG> where the servomotors are generally components of the inkers <NUM> themselves. In these embodiments, it is more accurate to say that the servomotors <NUM>, <NUM> are separate from the inkers <NUM> and, therefore, remain attached to the decorator <NUM> when one or more inkers <NUM> are removed.

This embodiment also includes a controller <NUM>. The controller <NUM> combined with the modified inkers <NUM>, servomotors <NUM>, <NUM>, and the decorator <NUM> form a decorating system that includes a capability of manually and/or automatically adjusting image alignment of decorated containers "on the fly" or during a production run without appreciably adversely affecting production rate or speed, at the very least, without having to cease the decorating operation to make changes to the register/alignment of the image on the containers. The controller <NUM> includes a memory and software stored on the memory to regulate the inkers and/or the servomotors <NUM>, <NUM>. This system is operable as described above.

The drive train shaft <NUM> is mounted on or supported by the inker frame plates <NUM>, <NUM> of the inker <NUM>. The drive train shaft <NUM> carries a drive gear <NUM>, such as an anti-backlash helical gear, which is driven by a bull gear <NUM> of the blanket wheel <NUM>. The drive train shaft <NUM> extends out of and beyond inker frame plate <NUM> and into the gear box <NUM>. A portion of the drive train shaft <NUM> within the gear box <NUM> carries a spur gear <NUM> used to rotate the drive train <NUM> within the gear box <NUM>. The drive train shaft <NUM> is bored to create a channel or passage <NUM> within which and through which the printing plate cylinder shaft <NUM> is fit and passes.

The printing plate cylinder shaft <NUM> extends out of opposite ends of the drive train shaft <NUM>. The printing plate cylinder <NUM> is affixed to a first end of the printing plate cylinder shaft <NUM>. An opposite second end of the printing plate cylinder shaft <NUM> extends beyond the spur gear <NUM> on the drive train shaft <NUM> and through and out of the gear box <NUM> and is operably joined to the angular adjustment servomotor <NUM>. The printing plate cylinder shaft <NUM> is movable within the drive train shaft <NUM>, both rotationally and axially.

The angular adjustment servomotor <NUM> is mounted on a bracket attached to the decorator <NUM>.

The lateral adjustment servomotor <NUM> is mounted with the angular adjustment servomotor <NUM> on the bracket to the decorator <NUM>. The lateral adjustment servomotor <NUM> does not contribute to the rotational drive of the printing plate cylinder shaft <NUM>. Instead, the lateral adjustment servomotor <NUM> is a linear servomotor. Alternatively, the lateral adjustment servomotor <NUM> is coupled to a linear drive plate <NUM> through a ball nut <NUM> and a ball screw <NUM>. The linear drive plate <NUM> engages a coupler <NUM> which operably joins the printing plate cylinder shaft <NUM> to the angular adjustment servomotor <NUM>.

This embodiment functions in the following manner. As the decorator blanket wheel <NUM> rotates in normal operation, the bull gear <NUM> attached to the blanket wheel <NUM> will rotate therewith. The rotation of the bull gear <NUM>, in turn, rotates the drive train shaft <NUM> by engagement with the drive gear <NUM>. The rotation of the drive train shaft <NUM> causes the spur gear <NUM> to rotate therewith. The spur gear <NUM> drives the drive train <NUM> causing the inker rolls other than the printing plate cylinder <NUM> to rotate. Thus, rotation of the drive train shaft <NUM> drives all of the rolls in the inker <NUM> by way of the spur gear <NUM>, but not the printing plate cylinder <NUM>.

Simultaneously, a sensor 242a, such as an encoder, senses the motion of the bull gear <NUM>. The sensor 242a generates a signal corresponding to the rotational speed by the bull gear <NUM>. A controller receives the signal, instructs the angular adjustment servomotor <NUM> to rotate its shaft in unison with the bull gear <NUM>, normally at exactly the same speed as the bull gear <NUM>, with an exception being when an angular correction is in the process of being made. The printing plate cylinder shaft <NUM> is attached to the rotational shaft of the angular adjustment servomotor <NUM> such that the angular adjustment servomotor <NUM> imparts the desired rotational speed to the printing plate cylinder <NUM> via the printing plate cylinder shaft <NUM>. This allows the printing plate cylinder shaft <NUM> to stay in time (synchronized) with the drive train shaft <NUM> which permits accurate ink transfer from the printing plate <NUM> attached to the printing plate cylinder <NUM> to a transfer blanket carried on the blanket wheel <NUM>.

The angular adjustment servomotor <NUM> driven by the printing plate cylinder shaft <NUM> ensures a perfectly matched speed with the entire decorator <NUM>. The angular adjustment servomotor <NUM> can incrementally rotate the printing plate cylinder shaft <NUM> to which the angular adjustment servomotor <NUM> is operably joined to adjust a rotational position of the printing plate <NUM> attached to the printing plate cylinder shaft <NUM> in relation to the transfer blanket <NUM>. In a case where a printed image resulting from a printing plate <NUM> on a printing plate cylinder <NUM> does not circumferentially match the images from other inkers on the transfer blanket, the angular adjustment servomotor <NUM> can make incremental rotational corrections by incrementally rotating the printing plate cylinder shaft <NUM> independent of any rotation by the drive train shaft <NUM>. One or more increments provided by the angular adjustment servomotor <NUM> to the printing plate cylinder shaft <NUM> can be determined based on an inspection of one or more of a decorated container and the transfer blanket. Thus, the angular adjustment servomotor <NUM> is configured to selectively alter a position of a graphic on a decorated cylindrical container in a direction about a circumference of the container from right to left or from left to right, as the container is standing on end.

The lateral adjustment servomotor <NUM> may be a linear servomotor. In the case where a printed image delivered by a printing plate <NUM> attached to a given printing plate cylinder <NUM> is out of registration, does not line up, or does not laterally match the images from the other inkers <NUM> on a given transfer blanket, the lateral adjustment servomotor <NUM> is activated to shift the printing plate cylinder shaft <NUM> inwardly or outwardly in a direction parallel to a rotational axis of the printing plate cylinder shaft <NUM> until the image matches. The lateral adjustment servomotor <NUM> is operably joined to the printing plate cylinder shaft <NUM> of an associated inker <NUM> and imparts a lateral adjustment to the printing plate cylinder shaft <NUM> in a direction parallel to a center axis of the two-piece shaft <NUM> of the associated inker <NUM> to adjust a position of the printing plate <NUM> of the associated inker <NUM> in relation to the transfer blanket <NUM>. A magnitude of the linear motion may be determined by an inspection of at least one of the beverage container and the transfer blanket.

As illustrated in <FIG>, the servomotors <NUM>,<NUM> can be supplied on a common assembly. This common assembly is attached to the decorator frame wherein the common assembly remains attached to decorator frame during swap outs of designs and changes of the inkers <NUM>. The common assembly includes the servomotors <NUM>,<NUM> mounted to a motor mount plate <NUM> by fasteners. The motor mount plate <NUM> is attached to a fixed plate <NUM>, which may be a portion of the decorator frame. The linear drive plate <NUM> is joined to a shaft of the angular adjustment servomotor <NUM> by the coupler <NUM>. The lateral adjustment servomotor <NUM> acts on the linear drive plate <NUM> to adjust the lateral position of the printing plate cylinder shaft <NUM>.

In one embodiment, the angular adjustment servomotor <NUM> is capable of incrementally correcting angular errors by rotating the printing plater cylinder shaft <NUM> less than <NUM> inches (<NUM>), and more preferably <NUM> inches (<NUM>). The printing plate cylinder is generally about <NUM> inches in circumference.

In one embodiment, the lateral adjustment servomotor <NUM> is capable of incrementally adjusting a position of the printing plate cylinder <NUM> laterally in a direction parallel to the axis of rotation of the printing plate cylinder shaft <NUM>. A range of lateral correction is <NUM> inches to <NUM> inches (<NUM> to <NUM>), more preferably <NUM> inches to <NUM> inches (<NUM> to <NUM>) and most preferably <NUM> inches to <NUM> inches (<NUM> to <NUM>).

Claim 1:
A decorator (<NUM>) for printing onto cylindrical structures comprising:
a plurality of inkers (12a-12f), each inker (<NUM>) comprising:
a pair of opposing frame plates (<NUM>, <NUM>);
a printing plate (<NUM>) affixed to a printing plate cylinder (<NUM>) carried by a rotational printing plate cylinder shaft (<NUM>) disposed between the opposing frame plates (<NUM>, <NUM>);
a main shaft (<NUM>) supporting the inker (<NUM>) on the decorator (<NUM>) wherein the pair of opposing frame plates (<NUM>, <NUM>) are slidable along a length of the main shaft (<NUM>);
a plurality of lateral adjustment servomotors (<NUM>), each lateral adjustment servomotor acting on a corresponding inker (<NUM>) to impart a movement by the inker (<NUM>) in a direction parallel to the length of the main shaft (<NUM>),
a blanket wheel (<NUM>) rotationally mounted on the decorator (<NUM>); and
a plurality of transfer blankets (14a-14f) attached to the blanket wheel (<NUM>) and rotational therewith,
wherein each transfer blanket (<NUM>) engages each of the printing plates (<NUM>) to receive quanity of the colored fluid therefrom, wherein a location of the colored fluid across a surface of each transfer blanket (<NUM>) is regulated by a servomotor in the plurality of lateral adjustment servomotors (<NUM>),
a plurality of rolls disposed between the opposing frame plates (<NUM>, <NUM>), each roll carried by a corresponding rotational shaft;
a drive train (<NUM>) comprising a plurality of gears, each gear attached to a rotational shaft,
wherein the drive train (<NUM>) is movable along the length of the main shaft (<NUM>) in response to a force provided by the servomotor in the plurality of lateral adjustment servomotors (<NUM>).