CA2202334A1 - Rotary flexographic printing press - Google Patents

Abstract

A rotary flexographic printing press includes a carriage supported on a frame for movement toward and away from an impression cylinder between a printing positionand an interrupted position, and a plate cylinder supported on the carriage for rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the impression cylinder. The carriage is moved by an interruption assembly including a pair of laterally spaced, elongated shuttles, each of which are supported on the frame for longitudinal shifting movement in a horizontal direction transverse to the axis of the impression cylinder, and an actuator that shifts each shuttle toward and away from the impression cylinder. Another carriage is supported on the frame for movement toward and away from the plate cylinder between a plurality of inking and interrupted positions, and an inking cassette is supported on the second carriage for inking the plate cylinder during printing. The inking cassette includes an inking roller and a supply reservoir.
A drive mechanism is provided for driving rotation of the inking roller, and includes a rotatable drive head supported on the carriage for movement with the inking cassette carriage toward and away from the plate cylinder. The inking roller engages and is rotated by the drive head.
A rotary web printing press includes an elongated frame defining a web travel path, and an anvil roller supported on the frame for rotation about a horizontal axis extending in a direction transverse to the web travel path. A carriage is supported on the frame for movement toward and away from the anvil roller between a die cutting position and an interrupted position in a direction transverse to the horizontal axis of the anvil roller, and a die roller is supported on the carriage for rotation about a horizontal axis extending in a direction parallel to the axis of the anvil roller. The axes of the anvil roller and die roller are disposed in a common horizontal plane. In addition, a pressure regulating assembly is provided for moving the carriage to the die cutting position and pressing the die roller against the anvil roller.
A rotary web printing press includes an elongated frame defining a web travel path and a dryer opening extending in a direction transverse to the web travel path.
A first pair of ventilation ducts communicate with the dryer opening, and a first power plug is accessible from within the dryer opening. A carriage is supported on the frame within the dryer opening and is sized for receipt of a dryer. The dryer includes a housing, a drying element, a mounting plate by which the housing is secured to the carriage, a second pair of ventilation ducts, and a second power plug. The mounting plate can be locked on the carriage when the dryer is positioned in the dryer opening or unlocked to permit the dryer to be removed from the opening. The second pair of ducts and the second plug are connected to the first pair of ducts and plug when the housing is inserted into the opening and are disconnected when the housing is withdrawn from the opening.

Description

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Rotary Flexographic Printing Press Background of the Invention 1. Field of the Invention The present invention relates generally to rotary web printing presses, and moreparticularly to a flexographic press having a construction which permits several of the 5 press components to be quickly changed over between runs and adjusted for proper operation.

2. Discussion of the Prior Art Flexographic web printing presses are conventionally used in the printing of a wide variety of materials such as packaging and the like, and typically include a 10 plurality of printing units, each provided with a flexographic plate cylinder, an impression cylinder opposing the plate cylinder to form a printing nip, and an inking assembly including an ink reservoir, an analox roller, and a ductor blade or the like for metering the application of ink to the analox roller. A drying station is also provided for drying the web between printing,operations and additional web handling equipmentsuch as one or more die units, slotters or the like are provided downstream of the printing units for preparing the web material for use. Each die unit includes a die roller on which a die is supported.
In order to change a conventional flexographic press over between runs, it is necessary to replace the plate cylinders and inking assemblies of the printing units, and to replace the die rollers of the die units. Such changeover of a five color press having three die units takes an average of two hours to complete. As such, it is not economically feasible to use such a flexographic press for relatively short runs of as little as ten minutes or less.

Objects and Summary of the Invention In light of the growing versatility of the flexographic process, and the desire of manufacture to reduce inventory and obtain labels and other materials "just in time" for use, it is an object of the present invention to provide an improved flexographic press construction that can be quickly changed over between runs, e.g. in ten minutes or - less, in order to economize use of the press for runs of any length.
It is another object of the present invention to provide a flexographic printingpress in which the plate cylinder of each printing unit is carried by a carriage on a pair of laterally spaced, longitudinally shiftable shuttles for movement between printing and 10 interrupted positions in order to facilitate quick replacement and registration of the plate cylinder. Another object is to provide a flexographic printing press in which the inking assembly of each printing unit is also carried by a carriage on the shuttles formovement between inking and interrupted positions in order to facilitate quick replacement and adjustment of the inking assembly.
It is yet another object of the present invention to provide a rotary web printing press in which the die roller of each die unit is mounted in a cassette and carried by a carriage for movement in a horizontal plane between a die cutting position and an interrupted position, and in which a pressure regulating means is provided for moving the carriage to the die cutting position and holding the die roller against the anvil roller.
Such a construction expedites changeover of the die roller and adjustment of thepressure between the die roller and the anvil roller.
Another object of the present invention is to provide a rotary web printing press in which the dryer associated with each printing unit is easily removable from the press and interchangeable to allow quick replacement.
In accordance with these and other objects evident from the following description of a preferred embodiment of the invention, a rotary flexographic printing press is provided which includes an elongated frame defining a web travel path, and an impression cylinder supported on the frame for rotation about a horizontal axis extending in a direction transverse to the web travel path. A first carriage is supported 3 o on the frame for movement toward and away from the impression cylinder between a printing position and an interrupted position in a direction transverse to the horizontal axis of the impression cylinder. A plate cylinder is supported on the first carriage for CA 02202334 l997-04-lO

rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the impression cylinder. The press also includes an interruption means for moving the first carriage between the printing and interrupted positions. The interruption means includes a pair of laterally spaced, elongated shuttles, each supported on the frame for longitudinal shifting movement in a direction transverse to the horizontal axis of the impression cylinder, and an actuator for shifting each shuttle longitudinally toward and away from the impression cylinder, the first carriage being secured to the shuttles for movement with the rails between the printing and interrupted positions.
By providing this type of construction of a flexographic press, numerous 10 advantages are realized. For example, by S~ ol ~ing the plate cylinder of each printing unit on a carriage that is, in turn, carried on a pair of longitudinally shiftable shuttles, it is possible to not only interrupt printing, but also to change out the plate and make pressure and registration adjustments by repositioning the carriage on the shuttles.
This operation is further facilitated by orienting the impression cylinder and plate cylinder in a common horizontal plane so that movement of the carriage longitudinally of the press adjusts the plate cylinder relative to the impression cylinder.
In accordance with another aspect of the present invention, a rotary flexographic printing press is provided which includes an elongated frame defining a web travel path, an impression cylinder supported on the frame for rotation about a horizontal axis, and a removable plate cylinder supported on the frame for rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the impression cylinder.
A carriage is supported on the frame for movement toward and away from the platecylinder between a plurality of inking and interrupted positions in a direction transverse to the horizontal axis of the plate cylinder, and an inking assembly is supported on the second carriage for inking the plate cylinder during printing. The inking assembly includes an inking roller supported for rotation about a horizontal axis extending in a direction parallel to the horizontai axis of the impression cylinder, and a supply means for supplying ink to the inking roller. A first drive means is provided for driving the impression cylinder, and a second drive means drives rotation of the inking roller in any of the inking positions. The second drive means includes a rotatable drive head supported on the carriage for movement with the carriage toward and away from the CA 02202334 l997-04-lO

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plate cylinder, the inking rolier engaging the drive head so that rotation of the inking roller is driven by the drive head.
Several advantages are obtained through the use of such a construction. For example, by providing an inking assembly that is supported on a carriage for movement 5 between a plurality of inking and interrupted positions, it is possible to quickly adjust ~ the position of the inking assembly or to change out the assembly and replace it with another. In addition, by providing a drive head on the carriage, it is possible for the press to accommodate plate cylinders of various diameters without increasing thechangeover time required by such changes.
10In accordance with others of the objects, a rotary web printing press is provided which includes an elongated frame defining a web travel path, and an anvil roller supported on the frame for rotation about a horizontal axis extending in a direction transverse to the web travel path. A carriage is supported on the frame for movement toward and away from the anvil roller between a die cutting position and an interrupted position in a direction transverse to the horizontal axis of the anvil roller. A die roller is supported on the carriage for rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the anvil roller, the horizontal axes of the anvil roller and die roller being disposed in a common horizontal plane. A pressure regulating means is provided for moving the carriage to the die cutting position and pressing the die roller against the anvil roller.
By providing this construction, several benefits arise. For example, by supporting the die roller on a carriage in a common horizontal plane with the anvil roller, it is possible to quickly change out the die roller between die cutting runs and adjust the pressure between the die roller and the anvil roller. In addition, the provision of the carriage facilitates regulation of the pressure between the die roller and the anvil roller and simplifies operation of the pressure regulating means.
In accordance with still others of the objects of the present invention, a rotary web printing press is provided which includes an elongated frame defining a web travel path and a dryer opening extending in a direction transverse to the web travel path, a first pair of ventilation ducts communicating with the dryer opening, and a first power plug accessible from within the dryer opening. A carriage is supported on the frame - within the dryer opening for supporting a dryer that includes a housing, a drying ' element supported within the housing, a mounting plate by which the housing is secured to the carriage, a second pair of ventilation ducts and a second power plug.
The press also includes a locking means for locking the mounting plate on the carriage when the dryer is positioned in the dryer opening, and for unlocking the mounting plate to permit the dryer to be removed from the opening. The second pair of ventilation ducts and the second power plug are connected to the first ducts and the first plug when the housing is inserted into the opening, and are disconnected when the housing is withdrawn from the opening.
By providing a press in accordance with the present construction, numerous advantages are realized. For example, by providing a dryer that is removably supported on a carriage within the dryer opening of the frame, a modular construction results which simplifies removal and replacement of the dryer while improving the versatility of the press by permitting the use of different types of dryers within the opening. Further, it is possible to support the carriage for longitudinal shifting movement relative to the frame to facilitate access to the dryer and to position the dryer relative to the web travel path.
~rief Description of the Drawing Figures The preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein:
Fig. 1 is a schematic plan view of a flexographic web printing press constructedin accordance with the preferred embodiment of the invention, and a make-ready area for permitting quick changeover and servicing of the press;
Fig. 2 is a schematic front elevational view of the press, illustrating the web travel path;
Fig. 3 is a perspective view of the press, illustrating an assembled printing unit and a partially assembled unit, both forming a part of the press;
Fig. 4 is a fragmentary view of an assembled printing unit;
Fig. 5 is a perspective view of the press, illustrating inking cassette carriages forming a part of the printing units and an inking cassette being assembled on one of the carriages;
Fig. 6 is a perspective view of a partially assembled printing unit, illustrating an interruption assembly forming a part of the press;

Fig. 7 is a side elevational view, partially in section, of an actuator and adjustment mechanism forming a part of the interruption assembly;
Fig. 8 is a perspective view of one of the inking cassette carriages;
Fig. 9 is a bottom plan view, partially in section, of a gripping mechanism and 5 adjustment mechanism forming a part of the inking cassette carriage;
Fig. 10 is a fragmentary end elevational view, partially in section, of the gripping mechanism and adjustment mechanism of the inking cassette carriage;
f ig. 11 is a perspective view of a transmission assembly for transmitting driveto a drive head forming a part of the inking cassette carriage;
lo Fig. 12 is a perspective view of the press, illustrating a pair of dryer assemblies forming a part of the press;
~ig. 13 is a side elevational view of a dryer forming a part of the dryer assemblies; and Fig. 14 is a perspective view of the press illustrating a pair of die units forming a part of the press.
Detailed Description of the Preferred Embodiment Aflexographic web printing press constructed in accordance with the preferred embodiment is shown in ~ig. 1, as is a make-ready area arranged for use with thepress. The press generally includes an elongated frame defining a web travel path, shown in Fig. 2, a web supply assembly 14, a plurality of printing units 16, one or more die units 18, and a take-up assembly 20. A raised walkway 22 extends along the front side of the press and is adapted to support a pressman while he or she works on the press.
The make-ready area is laid out beside the press and generally includes a cleaning facility 24, storage and preparation areas 26, 28, 30 for plate cylinders, inking cassettes, and die rollers, a test bench 32, and a temporary storage area for make-ready carts 34 loaded with newly prepared and tested inking cassettes and plate cylinders. These areas can either be provided together in one area as shown, or in different areas of the printing facility. However, use of the make-ready cart 34 is 3 o facilitated by providing the areas in general proximity to one another and to the press so that the pressman can prepare and test the plate cylinders, inking cassettes and die rollers quickly prior to each new run of the press. An example of a make-ready cart particularly adapted for use with the flexographic printing press of the preferred embodiment is disclosed in co-pending application l~lo. 08/641,910, filed May 2, 1996, and entitled "Printing Press Make-Ready Cart."
The press frame includes laterally spaced, longitudinally extending front and rear 5 side walls 36, 38 between which the cylinders and rollers of the printing units and die units are supported. In addition, a drive housing 40 is provided directly behind the rear side wall 38 for housing a line shaft and a number of transmission mechanisms for driving the press components.
AS shown in Figs. 3 and 14, the front side wall of the press is modular, being assembled from a plurality of C-shaped sections 42, 44, wherein a section 42 is associated with each printing unit 16, as shown in Fig. 3, and a section 44 is provided for each die unit 18, as shown in Fig. 14. With reference to Fig. 3, each printing unit section 42 has upper and lower longitudinally extending legs, and an upstanding vertical portion connecting the legs to one another. The shape of each printing unit section 42 defines a central opening 46 that permits access to the area within the frame between the side walls 36, 38. A longitudinally extending slot 48 is formed in the upper leg of each printing unit section 42 and is sized for receipt of an inking carriage adjustment mechanism that is described more fully below. A circular hole 50 is formed in the upper leg within which a plate cylinder adjustment mechanism is supported. An upstanding arm extends vertically from the upper leg of each section beyond the vertical portion. The arm defines a means for supporting a control pad 52 that is accessible by the pressman, as well as a means for supporting one end of an impression cylinder associated with the printing unit.
Each front side wall section 42 includes a longitudinally extending channel 54 adjacent the upper edge of the upper leg. The channel faces outward toward the front of the press and defines a means for supporting a longitudinally shiftable shuttle forming a part of an interruption mechanism that is described more fully below.
Turning to Fig. 14, at each die unit 18, the front wall section 44 includes upper and lower longitudinally extending legs and an upstanding vertical portion connecting 3 o the legs together. An upstanding arm extends vertically from each end of the upper leg of each section 44. One of the arms includes a C-shaped notch within which an anvil roller of the die unit is supported and the other arm defines a means for supporting a pressure regulating mechanism that is described more fully below. Each die unit section 44 also supports a longitudinally extending rail 56 on which a carriage forming a part of the die unit is supported.
The rear wall of the frame is also formed of printing unit sections 58, shown ins Fig. 3, and die unit sections 60, shown in Fig. 14. With reference to Fig. 3, each - printing unit section is substantially similar to the front wall section 42, and includes upper and lower longitudinally extending legs that are connected together by a vertical portion, an upstanding arm that supports an end of the impression cylinder, a longitudinally extending slot 48 for receiving the inking assembly adjustment o mechanism, a hole formed in the upper leg for receipt of the plate cylinder adjustment mechanism, and a longitudinally extending, outward facing channel 54 for receiving a longitudinally shiftable shuttle forrning a part of the interruption mechanism.
As illustrated in Fig. 14, the rear wall section 60 associated with each die unit is similar to the front wall section 44 in that it is C-shaped. However, the upper leg of each die unit rear wall section extends vertically to a height equal to the height of the arms of the front wall section. Thus, the upper leg defines a means for supporting an end of the anvil roller and an end of the pressure regulating mechanism. An opening is provided in the upper. Ieg for receiving the anvil roller and for permitting replacement of the roller.
The drive housing is shown in Fig. 1, and extends along the rear side wall of the frame. As shown in Fig. 3, the housing includes an upstanding wall 62 and a plurality of covers that are supported on the wall and extend to the rear of the press, as shown in Fig. 1. As shown in Fig. 11, a conventional line shaft 64 is housed within the housing and extends along and is supported by the side wall of the housing 40. A plurality of 2s gear boxes 66 are also supported within the housing and cooperate with the line shaft to provide drive to the impression cylinders and inking cassettes of each printing unit and to the anvil roller of each die unit during printing. The covers of the housing can be removed to allow access to the line shaft and the various gear boxes 66 located along the press. As shown in Fig. 3, a pair of vertically spaced, longitudinally extending 3 o slots 68, 70 are formed in the housing wall along the length of each printing unit and are adapted for receipt of the inking carriage so that drive can be provided to the inking roller during printing in a manner described below.

'' The printing units 16 are identical to one another, and each generally includes an impression cylinder 72, a plate cylinder 74, a plate cylinder carriage 76, an inking cassette 78, an inking cassette carriage 80, a dryer 82, shown in Fig. 12, and a dryer carriage 84. In addition, returning to Fig. 3, each printing unit includes a pair of 5 longitudinally shiftable shuttles 86 that support the plate cylinder carriage 76 and inking - cassette carriage 80 on the frame for movement relative to the impression cylinder 72.
The impression cylinder includes a central shaft by which it is supported between the arms of the front and rear side wall sections 42, 58 of the frame for rotation about the central longitudinal axis defined by the shaft. The cylinder includes an outer circumferential surface over which a web of substrate material is guided during printing, as shown in Fig. 2. A gear 88 is provided on the impression cylinder, as shown in Fig.

4, for transmitting rotation of the impression cylinder to the plate cylinder 74, which also includes a gear 90 in alignment with the gear of the impression cylinder. The end of the impression cylinder shaft extending through the arm on the rear side wall section ~8 of the frame is connected to the line shaft through one of the gear boxes so that rotation of the line shaft is transmitted through the gear box to the impression cylinder, and by the gears 88, 90 to the plate cylinder.
The plate cylinder 74 includes a relatively rotatable central shaft by which it is supported on the carriage 76 for rotation about the central longitudinal axis defined by the shaft. An outer circumferential surface of the plate cylinder is adapted for receipt of a conventional flexographic printing plate, and the gear 90 protrudes radially beyond the outer surface of the plate cylinder so as to engage the gear 88 of the impression cylinder when a plate is positioned on the plate cylinder and positioned for printing engagement with the impression cylinder.
The plate cylinder carriage 76 includes a transverse base plate 92 that spans the side walls of the frame. A pair of laterally spaced, upstanding support arms 94 are provided on the base plate for supporting the plate cylinder, and a U-shaped bearing block 96 is secured to the top of each support arm. Each bearing block defines alaterally extending channel sized for receipt of an end of the plate cylinder shaft so that the plate cylinder can be positioned on the carriage by simply being dropped into the bearing blocks A serpentine-shaped rocker arm 9~ is supported for pivotal movement on each bearing block between an unclamping position retracted from the channel and CA 02202334 l997-04-lO

a clamping position extending partially over the channel. A pneumatic actuator 100 is supported on the base plate outboard of each upstanding arm for moving the rocker arm 98 between the clamping and unclamping positions, and includes an axially shiftable output shaft that is connected to the rocker arm for pivoting the arm. 8y s providing this construction, it is possible to secure a plate cylinder on the carriage by - operating the actuators 100, pivoting the rocker arms 98 to the clamped position.
Likewise, in order to remove the plate cylinder it is only necessary to operate the actuators to shift the rocker arms to the unclamping position so that the plate cylinder can be lifted from the bearing blocks 96.
A pair of laterally spaced depending slides 102 are secured to the underside of the base plate for supporting the carriage for longitudinal shifting movement along rails 104 forming a part of the shuttles 86. The slides 102 each include a longitudinally extending channel having a cross-sectional shape corresponding to the cross-sectional shape of the rails and adapted to hold the carriage on the rails while permitting relative longitudinal shifting movement. A pair of depending blocks 106 are secured to the underside of the base plate between the slides, and support a gripping assembly 108 for locking the plate cylinder carriage in place on the shuttles 86 to prevent relative longitudinal shifting movement. The gripping assembly includes a pneumatic actuator 110 having two coaxial, laterally extending output shafts 1 12 that connect the actuator to a pair of wedge-shaped gripping elements 114 supported within channels 116 defined by the shuttles 86. Each wedge-shaped gripping element 114 supports a pair of wedge-shaped shoes 118 within the channel so that lateral shifting movement of the gripping elements away from one another forces the shoes against the top and bottom walls of the channel to secure the carriage in place, and shifting movement of the elements 1 14 toward one another releases the shoes 1 18 from engagement with the channel walls to permit relative longitudinal shifting movement.
The inking cassette 78 is shown in Fig. 5, and includes a base 120 on which a pair of upstanding end walls 122 are provided. The end walls include slots adapted for receipt of a conventional ink reservoir, and journals for receiving an analox inking roller 124. The analox roller is supported in the reservoir for rotation about the central longitudinal axis of the roller, and a ductor blade or the like can be provided for metering the application of ink to the roller. Preferably, the analox roller includes a support shaft defining the central longitudinal axis of the roller, and an outercircumferential surface that is textured to define many small interstices that carry ink for inking the plate during use. ~oth ends of the support shaft of the analox roller are provided with a hexagonal socket 126 sized for receipt of a rotatable drive head forming 5 a part of the inking cassette carriage 80, as described below, such that the roller can be rotated by the drive head.
The bottom of the base presents a laterally extending channel and a pair of depending wall sections on which guide rails 128 are secured. The guide rails each present an inner, V-shaped edge extending into the channel and defining a means for 10 supporting the inking cassette on the carriage. A vertically shiftable pin is supported on the base at the outboard end thereof, and extends through the base to permit the inking cassette to be secured in place on the carriage once the cassette is properly loaded onto the carriage.
The inking cassette carriage 80 includes a transverse base plate 130 that spans the side walls of the frame. A plurality of sheaved rollers 132 are secured to the upper surface of the base plate for rotation about parallel vertical axes, and are aligned with one another in two longitudinally spaced rows so that each row of rollers is engaged by one of the rails 128 of the inking cassette when the inking cassette is loaded onto the carriage. Thus, the sheaved rollers guide loading and unloading of the inking 20 cassette and accurately position the inking cassette on the carriage.
A pair of laterally spaced depending slides 134 are secured to the underside of the base plate 130 for supporting the carriage for longitudinal shifting movement along the rails 104. Each slide includes a longitudinally extending channel having a cross-sectional shape corresponding to the cross-sectional shape of the rail and adapted to 25 hold the carriage on the rail while permitting reiative longitudinal shifting movement.
A pair of depending arms 136 are secured to the underside of the base plate 130 between the slides 134, and support a gripping assembly 138, shown in Fig. 9, for locking the inking cassette carriage 80 in place on the shuttles 86 to prevent relative longitudinal shifting movement, and an adjustment mechanism 140 for adjusting the orientation and position of the carriage relative to the gripping assembly 138. The gripping assembly includes a laterally extending support plate 142, a pair of mounting blocks 144 secured to the support plate, and a pneumatic actuator 146 supported CA 02202334 l997-04-lO

between the mounting blocks and having two coaxial, laterally extending output shafts 148 that extend through the mounting blocks and connect the actuator to a pair of wedge-shaped gripping elements 150 supported within the channels defined by the shuttles. As shown in Fig. 10, each wedge-shaped gripping element 150 supports a5 pair of wedge-shaped shoes 152 within the channels so that movement of the gripping elements away from one another forces the shoes against the top and bottom walls of the channel to secure the carriage in place, and shifting movement of the elements toward one another releases the shoes from engagement with the channel walls to permit relative longitudinal shifting movement.
10Returning to Fig. 9, the gripping assembly 138 is connected to the base plate 130 through the adjustment mechanism 140 so that the relative longitudinal position of the inking cassette carriage can be adjusted relative to the plate cylinder and plate cylinder carriage while the gripping assembly 138 of the inking cassette carriage remains secured to the shuttles 86. As described below, this allows the pressman to adjust both the orientation of the analox roller relative to the plate cylinder and the pressure between the analox rqller and the plate cylinder. Also, this construction permits the plate cylinder and inking cassette to be moved together between the interrupted and printing positions upon longitudinal shifting movement of the shuttles.
The adjustment mechanism 140 includes a pair of laterally spaced pneumatic 20actuators 154, each secured to a bracket 156 connected to one of the depending arms 136 of the carriage 80. Each actuator 154 includes an output shafl 158 presenting two coaxial, longitudinally extending ends 160, 162 that extend from the ends of theactuator. An end 160 of the output shaft 158 is threaded, and is received in a threaded opening of the support plate 142. The end 162 of the output shaft is provided with a 25worm gear 164 that is rotated by one of a pair of manually actuated adjustment shafts , 166, 168 to rotate the output shaft 158 to thread the end 160 into and out of the support plate 142. A spur gear 170 is also supported on the end 162 of the output shaft for rotation therewith. As shown in Fig. 10, a spring biased ball-type detent 172 is provided on a mounting bracket 174 secured to each depending arm 136, and engages 30the spur gear 170 to provide a tactile, stepwise indication of the degree of rotation of the output shaft 1 ~8 in order to facilitate adjustment of the carriage.

CA 02202334 l997-04-lO

The adjustment shafts 166,168 are supported on the carriage by the brackets 174, and the inner shaft 16~ is received within the tubular outer shaft 168 and extends beyond the end of the outer shaft so that each actuator engages a different one of the shafts. Both shafts 166,168 are supported together within the slots 48 formed in the walls of the press. A gripping portion 176,178 is provided on the outboard end of each of the inner and outer shafts for permitting independent rotation of the shafts. However, each gripping portion includes an axially extending, arcuate slot that is aligned with the slot in the other gripping portion, and a threaded fastener extends through the slots for normally securing the gripping portions together. By providing this construction, the inner and outer shafts 166, 168 are normally rotated together as a unit but can, by loosening the threaded fastener, be rotated independently of one another. Thus, with reference to Fig. 9, longitudinal movement of the support plate 142 relative to the base plate 130 can be achieved either by axially shifting the output shafts 158 through operation of the actuators 154, or by rotating both of the shafts 166,168 simultaneously to thread the ends 160 of the output shafts into or out of the support plate. Likewise, it is possible to adjust the angular orientation of the base plate 130 relative to the support plate 142 by rotating the shafts relative to one another.
Turning to Fig. 5, the base plate 130 of the inking cassette carriage extends beyond the rear wall of the frame and through the slot 70 in the housing wall 62. In addition, a pair of upstanding parallel plates 180, 182 are secured to the base plate, wherein one of the plates 180 is disposed to the rear of the wall 62 and the other plate 182 is located on the front side of the wall. As shown in Fig. 8, the front plate 182 supports a rotatable drive head assembly that is adapted to transmit rotational drive to the analox roller 124. The drive head assembly includes a rotatable drive shaft 184 supported on the upstanding plates 180,182 by suitable bearing structure, wherein the drive shaft includes a polygonal drive head 185 sized and shaped for receipt in the socket of the analox roller upon assembly of the inking cassette on the carriage.
The rear plate 180 extends above the front plate behind the wall of the housing and supports the drive shaft 184 and a pair of idler rollers 188, as shown in Fig. 11.
A toothed pulley 190 is secured to the rear axial end of the drive shaft and extends to CA 02202334 l997-04-lO

the rear of the rear plate 180, and the idler rollers 188 are spaced above and to the sides of the pulley 190 so as to guide engagement between the pulley and a toothed drive belt 192 forming a part of the means for transmitting drive to the analox roller 124.
The drive means also includes three toothed pulleys 194,196,198 that are supported on the side wall 62 of the housing for rotation about parallel transverse axes - extending in a direction parallel to the drive shaft 184. The belt is trained around the drive head pulley 190 and the three fixed pulleys 194,196,198 so that rotation of any one pulley is transmitted to the others. The line shaft 64 extends past each printing unit 16, and the gear box 66 is provided for transmitting drive from the line shaft to the lO pulley 194 through a conventional one-way clutch assembly 200.
A Sunday drive motor 202 is supported within the housing and includes an output shaft 204 connected to the pulley 196 through a one-way clutch 206. During printing, the one-way clutch 206 allows the pulley 196 to rotate relative to the output shaft of the Sunday drive motor 202. However, when printing is interrupted, the drive shaft 184 is driven by the Sunday drive motor in order to rotate the analox rolier.
Typically, Sunday drive is carried out at a very slow speed relative to the normal printing speed for the purpose of maintaining the analox roller in a wetted condition If the analox roller is allowed to dry during an interruption in printing, the interstices in the analox roller become filled with dry ink, ruining the roller. Thus, by maintaining drive to the inking cassette, this problem is obviated.
An interruption assembly 208 is shown in Fig. 6, and includes the shuttles 86, one of which is supported on the front side wall section 42 of each printing unit and the other of which is supported on the rear side wall section 58. In addition, the assembly 208 includes of actuators 210 for simultaneously shifting the shuttles longitudinally of the press to move the plate cylinder carriage 76 and the inking cassette carriage 80 between printing and interrupted positions, and an adjustment mechanism 212 for adjusting the longitudinal positions of the shuttles relative to one another. The shuttles 86 are substantially similar to one another, and each includes an elongated bodyhaving an L-shaped uoss section presenting a top wall that is directed laterally outward 30 over the associated side wall section of the frame, and a depending, laterally inner side wall that runs along the inner surface of the frame side wall section. A pair of L-shaped runners 214 are secured to the top plate of each shuttle 86 and extend along the front CA 02202334 l997-04-lO
' surface of the side wall section. The runners extend into the channels 54 provided in the upper leg of the side wall sections 42, ~8 for allowing longitudinal shifting movement of the shuttle. Three guide rollers 216 are secured to the body at spaced locations along the length thereof for guiding the longitudinal movement. The axially extending channel 116 is formed in the side wall of each shuttle body and presents upper and lower channel walls that are engaged by the shoes of the gripping assemblies of the plate cylinder carriage and inking cassette carriage so that upon actuation of the gripping assemblies, the plate cylinder and inking cassette are secured to the shuttles 86 and move with the shuttles as a unit toward and away from theimpression cylinder 72 between a printing position in which the plate cylinder engages the impression cylinder and an interrupted position in which the plate cylinder is spaced from the impression cylinder. An arm 220 is secured to each shuttle body and depends downward from the shuttle for permitting connection between the shuttle and one of the actuators 21 0.
As shown in Fig. 7, each actuator 210 is supported on one of the side wall sections of the frame by a mounting bracket, and includes an output shaft 222 presenting two coaxial, longitudinally extending ends that extend from the ends of the actuator. One of the ends of the output shaft 222 is threaded, and is received in a threaded opening of the depending arm 220 of the shuttle. The opposite end of the output shaft 222 is provided with a worm gear 224 that is rotated by a worm gear 218 mounted on one of a pair of manually actuated adjustment shaRs 226, 228 to thread the output shaft into and out of the shuttle arm, as shown in Fig. 6. A spur gear 230 is also supported on the output shaR and engages a spring biased ball-type detent 232, shown in Fig. 7, to provide a tactile, stepwise indication of the degree of rotation of the output shaft in order to facilitate adjustment of the shuttles.
Returning to Fig. 6, the adjustment shafts 226, 228 are supported on the frame between the side walls, and the inner shaft 226 is received within the tubular outer shaft 228 and extends beyond the end of the outer shaR so that each shaft engages the worrn gear 224 on one of the actuators 210. A gripping portion 234 is provided on the 3 o outboard end of each of the inner and outer shafts for permitting independent rotation of the shafts. However, each gripping portion includes an axially extending, arcuate .

slot that is aiigned with the slot in the other gripping portion, and a threaded fastener extends through the slots for normally securing the gripping portions together.
By providing this construction, the inner and outer shafts are normally rotated together as a unit but can, by loosening the threaded fastener, be rotated independentiy of one another. Thus, simultaneous movement of the shuttles 86 relative to the frame can be achieved either by axially shifting the output shafts 222 through operation of the actuators 210, or by rotating both of the shafts to thread the ends of the output shafts into or out of the shuttle arms 220. Likewise, independent movement of each shuttle relative to the other can be achieved by rotating the shafts o 226, 228 relative to one another.
Turning to Fig. 12, the dryer 82 associated with each printing unit generally includes a housing within which a convection, ultra violet or other known type of drying mechanism is provided. A pair of laterally spaced rails 236 are secured to the side walls of the frame just inside of and beneath the openings 46 defined by the front and rear side wall sections of each printing unit. The carriage 84 is supported on the frame for movement along the side rails 236, and inciudes a pair of transverse base plates adapted to support the dryer. Each base plate preferably includes a rail or the like for guiding the dryer onto and off of the carriage during assembly and disassembly. An upstanding rear side wall 23~ is secured to the carriage at the rear end thereof and includes a pair of ventilation ducts 240, 242, and a power plug 244. The ducts are connected to a conventional air supply means through conduits. The power plug 244 is an electric socket and is connected to a conventional power source.
A transverse bar 246 extends between and is secured to the front and rear side wall sections of the frame and is connected to the carriage by a piston and cylinder assembly 248 which permits the carriage to be positioned longitudinally of the press along the rails 236.
As shown in Fig. 13, the dryer housing includes a mounting plate 258 by which the housing is secured to the carriage, a second pair of ventilation ducts 250, 252, and a second power plug 254. Returning to Fig. 12, the housing side walls substantially enclose the dryer and direct air over the drying elements to ventilate the housing during printing while the drying elements direct heat or light onto the web. A pair of handles 256 are provided on the housing for facilitating handling thereof, and the mounting CA 02202334 l997-04-lO

plate 2~8 presents a pair of longitudinally spaced, laterally extending edges that engage the rails 260 on the carriage to guide movement of the dryer onto and off of the carriage. The mounting plate and rails cooperate to align the ventilation ducts and power plugs with one another so that air and power can be supplied to the dryer once it is assembled on the carriage. Thereafter, the longitudinal position of the dryer can - be adjusted relative to the frame by shifting the carriage through the use of the piston and cylinder assembly. A threaded fastener is provided on the dryer and can be tightened down against the carriage upon assembly of the dryer for locking the mounting plate on the carriage when the dryer is positioned in the dryer opening.
lo As shown in Fig.14, each die unit 18 generally includes a die roller cassette 262 supported on a movable carriage 264, and an anvil roller 266 supported on the frame for rotation about a horizontal, transverse axis disposed in a common horizontal plane with the axis of a die roller 268 forming a part of the cassette 262. The anvil roller 266 is supported on the frame by suitable bearing structure permitting rotation of the anvil roller about the central longitudinal axis thereof. A gear box is provided at the rear end of the anvil roller for connecting the anvil roller to the line shaft so that the anvil roller is rotated during printing. A circumferential gear 270 is provided on the outer surface of the anvil roller adjacent the rear end for transmitting rotation of the anvil roller to the die roller.
The die roller 268 includes a central shaft by which it is supported on the cassette for rotation about the central longitudinal axis defined by the shaft. An outer circumferential surface of the die roller is adapted for receipt of a conventional die and a gear 272 is provided adjacent the rear end of the roller and protrudes radially beyond the outer surface of the die roller so as to engage the gear 270 of the anvil roller when a die is positioned on the die roller and pressed against the anvil roller.
The cassette 262 also includes an elongated base plate 274 having a pair of laterally spaced, upstanding mounting blocks 276 between which the die roller issupported. Preferably, suitable bearing structure is provided between each bearing block and the die roller shaft for permitting rotation of the die roller relative to the cassette, and handles 278 protrude from the mounting blocks for facilitating handling of the cassette. The base plate 274 includes a bottom wall defining an axially extending channel, and a pair of rails 280 extend along the edges of the bottom wall .

and protrude slightly into the channel. A vertically shiftable pin is supported on the base plate and protrudes therethrough for permitting the cassette to be locked in place on the carriage when the cassette is assembled.
The carriage 264 includes a transverse base plate 282 spanning the side walls of the frame, and includes a pair of depending slides 284 that are received on the rails 56 for guiding longitudinal shifting movement of the carriage. A plurality of sheaved rollers are supported on the base plate for guiding receipt of the rails 280 of the cassette during assembly of the cassette on the carriage. A hole is formed in the upper surface of the transverse plate for receiving the pin of the cassette to secure the 10 cassette on the carriage during use.
A pressure regulating assembly 288 is provided for pressing the die roller against the anvil roller during operation of the press and for releasing the die roller so that the die roller can be changed out between runs. The pressure regulating assembly includes a pair of pneumatic actuators 290 that are supported on the frame between a pair of transverse cross members 292. Each actuator 290 includes a longitudinally shiftable output shaft 294, and a block 296 is mounted on the distal end of the output shaft. A pair of vertically spaced rollers are supported on each block and protrude from the distal end thereof so that the rollers engage the die roller as the output shafts are extended. A cross piece 298 extends between and is connected to the blocks for coordinating movement of the output shafts.
During printing, the web passes through the printing units along the path shown in Fig. 2, and a color image is printed on the web. The web is guided through each printing unit and passes between the impression and plate cylinders 72, 74 and around the impression cylinder. Thereafter, the web is directed downward past the dryer 82 and then horizontally toward the next printing unit or die unit. The plate cylinder 74 of each printing unit engages the impression cylinder during printing to define the nip, and the anatox roller 124 of the inking cassette engages the plate cylinder and transfers ink thereto for printing. Drive from the line shaft 64 is transmitted to the impression cylinder through one of the gear boxes 66, and rotational drive is further transmitted to the plate cylinder by the gears 88, 90 on the impression and plate cylinders.
The analox roller of the inking assembly is driven independently of the impression and plate cylinders. Drive from the line shaft is transmitted to the analox CA 02202334 l997-04-lO

roller through another of the gear boxes 66, as shown in Fig. 11, through the output shaft connected to the pulley 194 through the one-way clutch 200. The pulley drives the belt which in tum rotates the pulley on the drive head of the inking cassette, rotating the analox roller.
Upon completion of printing, drive to the line shaft is interrupted and the plate cylinder and inking cassette of each printing unit is shifted longitudinally away from the impression cylinder to form a gap between the plate cylinder and impression cylinder and to remove the gear 90 of the plate cylinder from engagement with the impression cylinder gear 88, shown in ~ig. 3. This movement of the plate cylinder and inking o cassette is achieved by operating the actuators 210 of the interruption assembly 208, shown in Fig. 6, shifting the shuttles 86 longitudinally away from the impression cylinder. Because the plate cylinder carriage and inking cassette carriage are secured to the shuttles, as shown in Fig. 3, they move as a unit relative to the impression cylinder.
In order to separate the analox roller from the plate cylinder, the actuators 154 of the inking cassette carriage, shown in Fig. 9, are operated, shifting the base plate 130 of the carriage with the inking cassette 78 relative to the gripping assembly 138 that secures the carriage to the shuttles. Thus, the inking cassette is shifted longitudinally away from the plate cylinder.
Because the line shaft is stopped upon interruption of printing, it does not provide continued drive to the analox roller 124. However, with reference to Fig. 11, Sunday drive is provided by the motor 202. Specifically, the motor is operated during interruption of printing and rotates the output shaft 204 which is connected to the pulley 198 through the one-way clutch 206. The pulley 198 drives the belt 192 which, in turn, rotates the pulley 190 on the drive shaft 184, driving rotation of the analox roller. The one-way clutch 200 on the pulley 194 permits the pulley to rotate even though the output shaft of the gear box 66 is stationary. Likewise, during printing, the one-way clutch 206 on the pulley 196 allows the pulley to rotate when the output shaft 204 of the motor 202 is stationary. The Sunday drive continuously rotates the analox roller on the 3 o inking cassette to maintaining the analox roller in a wetted condition so that the roller is not ruined between printing runs.

CA 02202334 l997-04-lO
.

With reference to Fig. 4, the plate cylinder 74 is released from the carriage 76for removal by operating the actuators 100 on the plate cylinder carriage. This operation pivots the arms 98, uncovering the plate cylinder shaft so that the plate cylinder can be lifted from the carriage and replaced by a plate cylinder carrying a plate that is to be used in a subsequent printing run. Turning to Fig. 5, the inking cassette ~ 78 is changed out by lifting the locking pin to release the cassette for sliding movement on the sheaved rollers 132. Thereafter, the cassette is slid from the carriage and replaced by a new inking cassette carrying an ink for use in the subsequent printing run. As the new cassette is loaded onto the inking cassette carriage 80, the drive shaft 184 engages the analox roller shaft and maintains Sunday drive to the roller until the line shaft is engaged during the subsequent run.
With reference to Fig. 3, in order to register the new plate cylinder with the impression cylinder, a gauge is placed between the impression and plate cylinders, and the plate cylinder is moved longitudinally into engagement with the gauge, pinching the gauge between the cylinders. As shown in Fig. 4, such longitudinal movement of the plate cylinder is achieved by oper,ating the actuator 110 of the gripping assembly 108 to release the plate cylinder carriage from the shuttles 86 so that the plate cylinder carriage can be shifted relative to the shuttles toward and away from the impression cylinder. Thereafter, the actuator 110 is operated to secure the carriage to the shuttles.
At the beginning of the subsequent run, the actuators 210 of the interruption assembly, shown in Fig. 6, are operated and shift the plate cylinder carriage to position the plate cylinder in contact with the impression cylinder at iust the right pressure Turning to Fig. 9, if it is necessary to readjust the position of the analox roller relative to the plate cylinder, one or both of the shafts 176,178 associated with the inking cassette carriage 80 are rotated to shift the base plate 130 and inking cassette longitudinally relative to the gripping assembly 138. Likewise, the shafts 226, 228 of the interruption assembly 208 shown in Fig. 6, allow independent adjustment of each of the shuttles 86 relative to the impression cylinder to permit registration corrections to be made during printing.
3 o If a plate cylinder is replaced by a larger or smaller plate cylinder, no additional steps are required to register the plate cylinder with the impression cylinder or the analox roller since the analox roller is driven independently of the impression and plate CA 02202334 l997-04-lO

cylinders and because the cylinders and inking roller are disposed in a common horizontal plane. This feature of the preferred construction improves the versatility of the press while facilitating changeover between runs.
Turning to Fig.12, if it is necessary to replace one or more of the dryers 82 prior 5 to a subsequent run, the carriage 84 of each dryer assembly to be replaced is shifted - away from the web by the piston and cylinder assembly 248. Thus, the dryer is accessible and can be removed from the carriage by loosening the threaded fastener and sliding the dryer from the opening in the frame. Thereafter, a replacement dryer can be slid onto the carriage so that the ventilation ducts and power plug of the new dryer engage the ventilation ducts and power plug of the press, and the piston and cylinder assembly can be actuated to return the carriage to the use position. Likewise, adjustment of the position of the dryer toward and away from the web can be achieved through the use of the piston and cylinder assembly.
During die cutting, as shown in ~ig. 14, the web passes through each die unit and is cut into labels or the like for use in the particular application to be made of the web. The web is guided between the anvil and die rollers and around the anvil roller.
Thereafter, the web is directed downward and then horizontally toward the next die cutting unit. The die roller 268 of each unit engages the anvil roller 266 during die cutting. Drive from the line shaft 64 is transmitted to the anvil roller through one of the gear boxes 66 which includes an output shaft having a spur gear that engages a spur gear on the anvil roller shaft. Rotational drive is further transmitted to the die roller by the gears 270, 272 on the anvil and die rollers.
When die cutting is interrupted, the actuators 290 of the pressure regulating assembly 288 are operated to release the die roller 268 so that the die roller and carriage 264 separate from the anvil roller. Thereafter, the die roller cassette 262 can be removed from the carriage by lifting the locking pin and sliding the cassette from the carria~e. A replacement cassette can then be slid onto the carriage and locked in place prior to a subsequent run. The actuators 290 of the pressure regulating assembly 288 are operated to press the die roller against the anvil roller and to regulate the pressure at the nip between the rollers. The actuators can be operated independently of one another, if necessary, to adjust the pressure along the axes of the rollers.

By arranging the impression cylinder 72, plate cylinder 74 and analox roller 124of each printing unit in a common horizontal plane, as shown in Fig. 2, changeover of the plate cylinders and inking cassettes is simplified, and can be accomplished in just a few minutes. Likewise, by arranging the anvil and die rollers 266, 268 in a common 5 horizontal plane, similar advantages are realized with respect to changeover of the die units.
Further, by providing the interruption assembly along with independent carriagesfor the plate cylinder and inking cassette, replacement and registration of the plate cylinders and inking cassettes is greatly facilitated. In a like manner, the provision of 10 a carriage and a die roller cassette permits quick changeover of the die roller between runs. The use of such a carriage in connection with each dryer of the press further improves the versatility of the press relative to conventional constructions.
Although the present invention has been described with reference to the preferred embodiment, it is noted that equivalents may be employed and substitution made herein without departing from the scope of the invention as recited in the claims.

Claims (26)

1. A rotary flexographic printing press comprising:
an elongated frame defining a web travel path;
an impression cylinder supported on the frame for rotation about a horizontal axis extending in a direction transverse to the web travel path;
a plate cylinder carriage supported on the frame for movement toward and away from the impression cylinder between a printing position and an interrupted position in a direction transverse to the horizontal axis of the impression cylinder;
a plate cylinder supported on the plate cylinder carriage for rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the impression cylinder; and an interruption means for moving the plate cylinder carriage between the printing and interrupted positions, the interruption means including a pair of laterally spaced, elongated shuttles, each supported on the frame for longitudinal shifting movement horizontally in a direction transverse to the axis of the impression cylinder, and an actuator for shifting each shuttle longitudinally toward and away from the impression cylinder, the plate cylinder carriage being secured to the shuttles for movement with the shuttles between the printing and interrupted positions.

2. A rotary flexographic printing press as recited in claim 1, further comprising:
an inking cassette carriage supported on the frame for movement toward and away from the plate cylinder carriage between a plurality of inking and interrupted positions in a horizontal direction transverse to the axis of the impression cylinder; and an inking cassette supported on the inking cassette carriage for inking the plate cylinder during printing, the inking cassette including an inking roller supported for rotation about a horizontal axis extending in a direction parallel to the axis of the impression cylinder, and a supply means for supplying ink to the inking roller, the axes of the impression cylinder, plate cylinder, and inking roller being disposed in a common horizontal plane.

3. A rotary flexographic printing press as recited in claim 2, further comprising a first drive means for driving rotation of the impression cylinder during printing, and a second drive means for driving rotation of the inking roller during printing, the plate cylinder being driven by the impression cylinder.

4. A rotary flexographic printing press as recited in claim 1, further comprising a means for detaching the plate cylinder carriage from the shuttles to permit adjustment of the printing gap between the plate cylinder and the impression cylinder.

5. A rotary flexographic printing press as recited in claim 2, further comprising a means for detaching the inking cassette carriage from the shuttles to permit the inking roller to be removed from contact with the plate cylinder.

6. A rotary flexographic printing press as recited in claim 1, wherein the interruption means includes an adjustment means for adjusting the longitudinal position of each shuttle relative to the other in order to adjust the orientation of the horizontal axis of the plate cylinder relative to the impression cylinder.

7. A rotary flexographic printing press as recited in claim 2, wherein the inking cassette carriage includes an adjustment means for adjusting the orientation of the horizontal axis of the inking roller relative to the horizontal axis of the plate cylinder.

8. A rotary flexographic printing press comprising:
an elongated frame defining a web travel path;
an impression cylinder supported on the frame for rotation about a horizontal axis;
a removable plate cylinder supported on the frame for rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the impression cylinder;
a first drive means for driving rotation of the impression and plate cylinders;
an inking cassette carriage supported on the frame for movement toward and away from the plate cylinder between a plurality of inking and interrupted positions in a horizontal direction transverse to the axis of the plate cylinder;
an inking cassette assembly supported on the inking cassette carriage for inking the plate cylinder during printing, the inking cassette including an inking roller supported for rotation about a horizontal axis extending in a direction parallel to the axis of the impression cylinder, and a supply means for supplying ink to theinking roller; and a second drive means for driving rotation of the inking roller, the second drive means including a rotatable drive head supported on the carriage for movement with thecarriage toward and away from the plate cylinder, the inking roller engaging thedrive head so that rotation of the inking roller is driven by the drive head.

9. A rotary flexographic printing press as recited in claim 8, wherein the inking cassette carriage includes an adjustment means for adjusting the orientation of the horizontal axis of the inking roller relative to the axis of the plate cylinder.

10. A rotary flexographic printing press as recited in claim 8, wherein the inking cassette is removable from the carriage, the carriage including a guide means for guiding receipt of the inking cassette on the carriage so that the inking roller engages the drive head of the drive means.

11. A rotary flexographic printing press as recited in claim 10, wherein the guide means includes a plurality of sheaved rollers for guiding movement of the inking cassette onto and off of the carriage and for positioning the cassette on the carriage.

12. A rotary flexographic printing press as recited in claim 8, wherein the second drive means includes a belt connected between the drive head and the first drive means, and a first clutch interposed between the first drive means and the belt.

13. A rotary flexographic printing press as recited in claim 12, wherein the second drive means further includes a Sunday drive means for rotating the inking roller when the first drive means is stopped.

14. A rotary flexographic printing press as recited in claim 13, wherein the drive head is connected to the Sunday drive means by the belt, and the second drive means further includes a second clutch interposed between the belt and the Sunday drive means for coupling the drive head to the Sunday drive means.

15. A rotary flexographic printing press as recited in claim 8, further comprising a pair of laterally spaced, elongated shuttles supported on the frame, the carriage including a gripping means cooperating with the shuttles for guiding relative shifting movement of the carriage between the plurality of inking and interrupted positions and for selectively locking the carriage in place.

16. A rotary flexographic printing press as recited in claim 15, further comprising an interruption means for shifting the carriage relative to the plate cylinder while the carriage is locked in place to space the inking cassette from the plate cylinder.

17. A rotary web printing press comprising:
an elongated frame defining a web travel path;
an anvil roller supported on the frame for rotation about a horizontal axis extending in a direction transverse to the web travel path;
a carriage supported on the frame for horizontal movement toward and away from the anvil roller between a die cutting position and an interrupted position in a direction transverse to the axis of the anvil roller;
a die roller supported on the carriage for rotation about a horizontal axis extending in a direction parallel to the horizontal axis of the anvil roller, the horizontal axes of the anvil roller and die roller being disposed in a common horizontal plane;
and a pressure regulating means for moving the carriage to the die cutting position and pressing the die roller against the anvil roller.

18. A rotary web printing press as recited in claim 17, further comprising a pair of laterally spaced, elongated rails supported on the frame, the carriage cooperating with the rails for guiding relative shifting movement of the carriage between the die cutting and interrupted positions.

19. A rotary printing press as recited in claim 17, further comprising a drive means for driving rotation of the anvil roller and the die roller during die cutting.

20. A rotary web printing press as recited in claim 17, further comprising a cassette in which the die roller is mounted, the cassette being removable from the carriage.

21. A rotary web printing press as recited in claim 20, wherein the carriage includes a guide means for guiding receipt of the cassette on the carriage.

22. A rotary web printing press comprising:
an elongated frame defining a web travel path and a dryer opening extending in a direction transverse to the web travel path;
a first pair of ventilation ducts communicating with the dryer opening;
a first power plug accessible from within the dryer opening;
a carriage supported on the frame within the dryer opening;
a dryer including a housing, a drying element supported within the housing, a mounting plate by which the housing is secured to the carriage, a second pair of ventilation ducts in communication with the first pair of ducts, and a second power plug connected to the first plug; and a locking means for locking the mounting plate on the carriage when the dryer ispositioned in the dryer opening, and for unlocking the mounting plate to permit the dryer to be removed from the opening, the second pair of ventilation ducts and the second plug being connected to the first pair of ducts and the first plug as the housing is inserted into the opening and being disconnected from the first pair of ducts and the first plug when the housing is withdrawn from the opening.

23. A rotary web printing press as recited in claim 22, wherein the carriage is movable longitudinally of the frame.

24. A rotary web printing press as recited in claim 24, further comprising a means for moving the carriage relative to the frame.

25. A rotary web printing press as recited in claim 22, wherein the drying element is a heater.

26. A rotary web printing press as recited in claim 22, wherein the drying element is an ultraviolet light source.