Patent Application
20100043658
The present invention relates generally to printing presses and more specifically to a device for varying the size of cylinders in a printing press.
U.S. Pat. No. 4,144,812 discloses a printing sleeve in a printing roll wherein the outer surface of a roll core and preferably the inner surface of the sleeve are made with one end of a lesser diameter than the other; the sleeve is slightly undersize diametrically. Remote from the ends of the core are orifices whereby gas under pressure may be blown radially outwardly from the core. The difference in diameter allows the sleeve to be passed freely along the core until it jams up against an increased diameter portion of the outer surface of the roll, at which time it covers the orifices. Gas is then blown from the orifices to expand the sleeve which can then be moved into its working position on the core.
U.S. Pat. No. 5,950,536 discloses a fixed cutoff press is adapted to a variable cutoff press while maintaining the size of the blanket cylinders. A plate cylinder is mounted on a frame and includes a plate cylinder sleeve and a blanket cylinder is mounted on the frame, includes with a gapless blanket cylinder sleeve. The plate cylinder sleeve is variable, whereby a length of an image to be printed is varied proportionally to the variable outer diameter while maintaining the outer diameter of the gapless blanket cylinder sleeve constant. The size of a plate cylinder is changed by using a sleeve mounted over the plate cylinder or adding packing under a plate to increase the diameter of the plate cylinder.
U.S. Pat. No. 6,082,261 discloses a plate cylinder including a plate cylinder body; a first partially cylindrical image carrying shell and a second partially cylindrical image carrying shell, the shells being removably fastened to the plate cylinder body. Printing plates can be prefastened to the shells. A shell is connected to plate cylinder body by threaded bolts on shell and interface locking nuts, which can be rotated by rotating drivers in plate cylinder body so as to lock the shell to the plate cylinder body.
A variable-diameter printing press cylinder is provided. The variable-diameter printing press cylinder includes a cylinder body, a first shell segment having a first circumferential end portion and a second shell segment having a second circumferential end portion. The first and second shell segments are mounted on the cylinder body via the first and second circumferential end portions.
A method of varying a circumference of a cylinder in a printing press is also provided. The method includes the steps of mounting a segmented cylinder sleeve including a first shell segment and a second shell segment on a cylinder body in a printing press via a first circumferential end portion of the first shell segment and a second circumferential end portion of the second shell segment; removing the segmented cylinder sleeve from the cylinder body; and mounting a replacement segmented cylinder sleeve including a first replacement shell segment and a second replacement shell segment on the cylinder body via a first circumferential end portion of the first replacement shell segment and a second circumferential end portion of the second replacement shell segment. The replacement segmented cylinder sleeve has an effective diameter of a length that is different from a length of an effective diameter of the segmented cylinder sleeve.
The present invention is described below by reference to the following drawings, in which:
Longitudinal locking edges 23 of shell segment 22 include male locking devices 24 and longitudinal locking edges 13 of shell segment 12 include female locking devices 14. Interiors of shell segments 12, 22 include radial supports 16, 26, respectively, which run circumferentially within outer surfaces 17, 27 of shell segments 12, 22, respectively. Radial supports 16, 26 define inner circumferences 18, 28 of shell segments 12, 22, respectively. Radial supports 16 run between longitudinal locking edges 13 and radial supports 26 run between longitudinal locking edges 23. Male locking devices 24 are located on longitudinal locking edges 23 of radial supports 26 and extend outward from shell segment 22 past longitudinal locking edges 23. Female locking devices 14 are cut-out in radial supports 16 and extend inward towards shell segment 22 away from edges 13.
Shell segments 12, 22 may be connected by inserting male locking devices 24 into female locking devices 14. In one embodiment, segmented cylinder sleeve 10 may be mounted on cylinder body 20 by contacting cylinder body 20 with inner circumferences 18, 28 of shell segments 12, 22, respectively, such that male locking devices 24 are axially offset from female locking devices 14 and longitudinal locking edges 23 of shell segment 22 are contacting longitudinal locking edges 13 of shell segment 12. Axial positioning of shell segments 12, 22 may be adjusted so that female locking devices 14 engage male locking devices 24. This interlocked axial positioning may be maintained by inserting fasteners, such as bolts 40, radially inward through axial extensions 32, 42 of shell segments 12, 22, respectively, or some other part of shell segments 12, 22 and into cylinder body 20. Cylinder body 20 may include holes to receive bolts 40.
Unlocking may be achieved for example through force against a locking friction force or via a release mechanism. If bolts 40 are employed, bolts 40 are removed before unlocking. Locking devices 14, 24 may be manually or automatically actuated to lock and unlock shell segments 12, 22. In an alternative embodiment, locking device 14, 24 may be replaced by magnets at circumferential end portions 15, 25.
Printing plates or printing blankets may be placed on outer circumferences of cylinder sleeves 10, 110 when sleeves 10, 110 are mounted on cylinder body 20. Thus, cylinder body 20 may be a blanket cylinder body or a plate cylinder body. In alternative embodiments cylinder body 20 may be a transfer cylinder, an impression cylinder or any other type of cylinder used in a printing press. When cylinder body 20 is used as a plate or blanket cylinder body in a printing press, segmented cylinder sleeves can be used to vary a cutoff length of images printed by the printing press. Segmented cylinder sleeves of varying diameters may be provided and may be installed and uninstalled on cylinder body 20. Plates and blankets having printing surfaces of different lengths may be placed on the segmented cylinder sleeves in order to change the cutoff length of images printed by the printing press.
Segmented cylinder sleeve 110 shown in
Shell segments 212, 222 may be mounted on cylinder body 200 so that respective longitudinal edges 213, 223 of shell segments 212, 222 contact each other at a non-lock-up location 255, but are separated by a minimal gap at a lock-up location 265. To mount shell segment 222 on cylinder body 200, cylinder body 200 may include locking devices 224 that connect circumferential end portions 225 of shell segment 222 to cylinder body 200 at locations 255, 265. Locking devices 224 may engage radial supports 226 at circumferential end portions 225 of shell segment 222. Radial supports 226 and locking devices 224 may be shaped to help locking devices 224 engage radial supports 226. Radial supports 226 and locking devices 224 may also be designed with rough surfaces that provide a frictional force to help removably fix shell segment 222 to cylinder body 200. Cylinder body 200 may also includes radial grooves 245 that receive radial supports 226 at circumferential end portions 225. Grooves 245 may be cut into cylinder body 200 and may prevent axial sliding of shell segment 222. Grooves 245 may be roughened or shaped to provide a tangential force against shell segment 222, which may help removably fix shell segment to cylinder body 200.
Cylinder body 200, at locations 255, 265, may include locking devices similar to locking devices 224 and radial grooves 235 similar to radial grooves 245, which may removably fix circumferential end portions 215 of shell segment 212 to cylinder body 200 via radial supports 216. Shell segments 212, 222 may also be secured to cylinder body 200 by bolts in the same manner as shell segments 12, 22 may be secured to cylinder body 20 by bolts 40 (
Cylinder body 200, at location 255, includes a lock-up device 250 which may secure a plate or blanket about the surface of segmented cylinder sleeve 210. Ends of a plate or blanket may pass through a slot 244 on the surface of cylinder body 200 and a gap between circumferential end portions 215, 225 and be engaged by lock-up device 250.
Segmented cylinder sleeve 210 may be replaced by a segmented cylinder sleeve configured in the same manner as segmented cylinder sleeve 210, but that has a larger or smaller outer circumference in order to change the cutoff length of images printed by cylinder 211. Shell segments 212, 222 may be removed by sliding shell segments so that circumferential end portions move tangentially away from cylinder body 200 with sufficient force to overcome forces between radial supports 216, 226 and corresponding locking devices 224 and forces between radial supports 216, 226 and corresponding grooves 235, 245. Shell segments of a larger or smaller size than shell segments 212, 222 may be slid on cylinder body 200 in grooves 235, 245 to replace shell segments 212, 222.
Plates 92, 96 transfer images having a cutoff length to blankets 94, 98, respectively, which print the images on a moving web 70. Each cylinder 62, 64, 66, 68 has the same outer circumference. Outer circumferences of cylinders 62, 64, 66, 68, and thus the cutoff length of images printed by cylinders 62, 64, 66, 68, may be varied by removing plates 92, 96 and blankets 94, 98 and sleeves 82, 84, 86, 88 from cylinder bodies 72, 74, 76, 78. New sleeves sized to fit new plates and blankets having outer circumferences that can print images having a new cutoff length, as desired by an operator, may be installed on cylinder bodies 72, 74, 76, 78, and the new plates and blankets may be installed on the new sleeves to allow printing press 60 to print images having a new desired cutoff length.
More than one axially extending lock-up device may be provided on the circumference of each cylinder sleeve 82, 84, 86, 88.
In alternative embodiments, cylinder sleeves 10, 82, 84, 86, 88, 110, 210 may each include more than two shell segments.
In the preceding specification, the invention has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.
