The present disclosure relates to printing presses, and more particularly to an improved cylinder support for printing presses that may improve the dynamic stability of the printing cylinders mounted on the printing press.
On printing presses, conventional cylinders typically have a support shaft protruding from each end. These support shafts typically are integrally formed with the balance of the cylinder by turning down the ends of the cylinder. The protruding ends of the cylinder then are mounted to the supporting frame of the printing press using journal support bearings.
Such a conventional configuration creates a relatively long span for the printing cylinder. As is known, the longer the span of a printing cylinder, the more the cylinder is subject to bending forces. These bending forces cause the middle of the cylinder to deflect or sag to some extent. In printing presses, the normal structural sag of a cylinder may contribute to dynamic instability during operation of the printing press. Accordingly, improvements in cylinder design and/or support may lessen the amount of cylinder deflection.
In accordance with an aspect of the invention, a printing press having an inboard cantilever cylinder support comprises a frame having a drive side and a non-drive side, a cylinder having an axis and a drive end and a non-drive end. A drive aperture extends axially into the cylinder from the drive end, while a non-drive aperture extends axially into the cylinder from the non-drive end. A drive shaft is rotatably mounted to the drive side of the frame and is arranged for connection to a power source, while a drive coupling is disposed within the drive aperture of the cylinder and operatively connects the drive shaft to the drive aperture. A mandrel is carried by the non-drive side of the frame and extends into the non-drive aperture.
In further accordance with a preferred embodiment, the drive coupling is a splined connection, and a portion of the drive shaft is positioned to support the drive end of the cylinder. The drive shaft may be supported on the drive side of the frame by a first bearing set, and the non-drive end of the cylinder is supported on the mandrel by a second bearing set disposed within the non-drive aperture. The drive shaft and/or the mandrel may include one or more lubrication ports in flow communication with the drive coupling or the bearing set supported by the mandrel.
Each of the mandrel and the drive shaft may be supported on the sides of the press frame by an eccentric connection. Suitable seals may be disposed adjacent the non-drive end of the cylinder and encircling the mandrel, or around the drive shaft at the outer end of the drive side aperture. A sidelay registration mechanism may be provided to shift the cylinder axially relative to the frame. The mandrel may include a bearing set disposed within the non-drive aperture and rotatably supporting the non-drive end of the cylinder, and the sidelay registration mechanism may include an adjuster rod extending through the mandrel to the bearing set and arranged to shift the bearing set axially relative to the mandrel. The bearing set on the mandrel may include a race fixed within the non-drive aperture.
In accordance with another aspect of the invention, a printing press having inboard cantilevered cylinder supports includes a frame with a drive side spaced from a non-drive side, and the press includes a cylinder defining an having an axis and having a drive end and a non-drive end. The drive end includes a drive aperture extending axially into the cylinder and a splined insert mounted within the drive aperture, while the non-drive end includes a non-drive aperture extending axially into the cylinder. A drive shaft is rotatably mounted to the drive side of the frame and is arranged for connection to a power source. The drive shaft includes a spline sized to engage the splined insert and is arranged to a portion of the cylinder, while a mandrel carried by the non-drive side of the frame extends into the non-drive aperture and is arranged to support another portion of the cylinder.
In another aspect, a method of supporting a cylinder on a printing press comprises forming a drive side aperture in a drive end of the cylinder, forming a non-drive side aperture in a non-drive end of the cylinder, providing a cantilevered driveshaft mountable to a drive side of the frame and arranged for connection to a power source, and providing a cantilevered mandrel mountable to a non-drive side of the frame. A drive coupling is disposed inside the drive side aperture and operatively couples the drive end of the cylinder to the drive shaft and permits the driveshaft to support a first portion of the cylinder, while providing a bearing set disposed within the non-drive aperture permits support of a second portion of the cylinder.
Although the following text sets forth a detailed description of one or more exemplary embodiments of the invention, it should be understood that the legal scope of the invention is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment of the invention since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the invention.
Referring now to
A drive aperture 24 extends into the drive end 20 of the cylinder 12, while a non-drive aperture 26 extends into the non-drive end 22 of the cylinder 12. A driveshaft 28 is rotatably mounted to the drive side 16 of the frame 14 by a bearing set 30, and an outer end 32 of the driveshaft 28 is arranged for connection to a power source such as a drive motor (not shown) of the type commonly employed on printing presses. Preferably, the bearing set 30 is mounted within an eccentric adjuster 34 which permits the cylinder 12 to be shifted in a direction perpendicular to the axis A. In the disclosed example, the bearing set 30 has a first bearing 30a and a second bearing 30b. A drive coupling 36 operatively connects an inner portion 38 of the shaft 28 to and inner surface 40 of the drive aperture 24, such that rotation of the driveshaft 28 about its longitudinal axis will cause rotation of the cylinder 12 about its axis A.
A mandrel 42 is mounted to the non-drive side 18 of the frame 14, and an inner portion 44 of the mandrel 42 is disposed inside the non-drive aperture 26. The mandrel 44 is mounted to an eccentric adjuster 46 which, in conjunction with the eccentric adjuster 34, permits the cylinder 12 to be shifted in a direction perpendicular to the axis A. The inner portion 44 of the mandrel 42 supports a portion of the cylinder 12 using a bearing set 48 disposed inside the non-drive aperture 26, while the inner portion 38 of the driveshaft 28 supports another portion of the cylinder 12. Preferably, the bearing set 48 will have a pair of bearings 48a and 48b.
The driveshaft 28 is mounted to the drive side 16 of the frame 14 (or mounted to the eccentric adjuster 34) such that the inner portion 38 of the driveshaft 28 extends inwardly from the drive side 16 in cantilever fashion. Similarly, the mandrel 42 is mounted to the non-drive side 18 of the frame 14 (or mounted to the eccentric adjuster 46) such that the inner portion 44 of the mandrel 42 extends inwardly from the non-drive side 18 and cantilever fashion. In the example of
The mandrel 42 includes a lubrication port 58 having a first portion 60 that extends toward the inner portion 44 of the mandrel 42, and a second portion 62 that extends to a grease fitting 64. The lubrication for 58 provides suitable lubrication to the bearing set 48 on the inner portion 44 of the mandrel 42. The lubrication port 58 may include a third portion 66 that connects the innermost part of the lubrication port 58 to the bearing set 48.
The mandrel 42 includes a first part 68 having a first diameter, and a second part 70 having a reduced diameter. The bearing set 48 is mounted two the second part 70. Preferably, an inner race 72 of the bearing set 48 may be mounted about the second part 70, and may be secured with an end cap 72 secured by a suitable bolt 74. Still preferably, a seal 76 is mounted to the non-drive end 22 of the cylinder 12 and encircles the first part 68 of the mandrel 42. The seal 76 may be removable using a series also attachment bolts, screws or other suitable fasteners. A seal 78 may be connected to the drive side 16 of the cylinder 12 in a similar fashion.
In operation, upon connecting the driveshaft 28 to a suitable power source as described above, it will be appreciated that rotation of the driveshaft 28 about it's axis (which is substantially coaxial with the axis A of the cylinder 12) causes rotation of the cylinder 12. The cantilevered driveshaft 28 supports the drive end 20 of the cylinder 12 at a point spaced inwardly along the axis A from the drive end 20. Similarly, the non-drive end 22 of the cylinder 12 is supported on the bearing set 48 carried by the inner portion 44 end of the cantilevered mandrel 42, such that the non-drive end 22 of the cylinder 12 is supported at point space inwardly along the axis from the non-drive and 22. Consequently, in accordance with the disclosed example, any deflection measured at a central portion 80 will be less than the measured deflection of a conventional cylinder having the same the same length measured from the drive end 20 to the non-drive end 22, but having the conventional protruding shafts. Consequently, the cylinder 12 assembled in accordance with the teachings of the present invention may experience less dynamic instability during operation of the printing press. This lessened dynamic instability may be achieved, at least in part, by a shorter effective length between the points of support.
Referring now to
The printing press 100 includes a frame 114 having a drive side 116 and a non-drive side 118. The cylinder 112 includes a drive end 120, a non-drive end 122, and defines a longitudinal axis A. A drive aperture 124 extends into the drive end 120 of the cylinder 112, while a non-drive aperture 126 extends into the non-drive end 122 of the cylinder 112. A driveshaft 128 is rotatably mounted to the drive side 116 of the frame 114 by a bearing set 130, and an outer end 132 of the driveshaft 128 is arranged for connection to a power source such as a drive motor (not shown) of the type commonly employed on printing presses. Preferably, the bearing set 130 is mounted within an eccentric adjuster 134 which permits the cylinder 112 to be shifted in a direction perpendicular to the axis A. In the disclosed example, the bearing set 130 has a first bearing 130a and a second bearing 130b. A drive coupling 136 operatively connects an inner portion 138 of the shaft 128 to the cylinder 112 in order to transmit rotation of the shaft 128 to the cylinder 112. A mandrel 142 is mounted to the non-drive side 118 of the frame 114, and an inner portion 144 of the mandrel 142 is disposed inside the non-drive aperture 126. The mandrel 142 is mounted to an eccentric adjuster 146 which, in conjunction with the eccentric adjuster 134, permits the cylinder 112 to be shifted in a direction perpendicular to the axis A.
The inner portion 144 of the mandrel 142 supports a portion of the cylinder 112 using a bearing set 148 disposed inside the non-drive aperture 126, while the inner portion 138 of the driveshaft 128 supports another portion of the cylinder 112. Preferably, the bearing set 148 will have a pair of bearings 148a and 148b.
The driveshaft 128 is mounted to the drive side 116 of the frame 114 (or mounted to the eccentric adjuster 134) such that the inner portion 138 of the driveshaft 128 extends inwardly from the drive side 116 in cantilever fashion. Similarly, the mandrel 142 is mounted to the non-drive side 118 of the frame 114 (or mounted to the eccentric adjuster 146) such that the inner portion 144 of the mandrel 142 extends inwardly from the non-drive side 118 in cantilever fashion.
In the example of
The inner portion 138 of the driveshaft 128 includes a bearing face 182, with the bearing face 182 being formed generally adjacent to the splines 150. The cup insert 141 also includes a bearing face 184, such that the bearing faces 182 and 184 mate to support the drive end 120 of the cylinder 112. The cup insert 141 is sized for insertion in the drive aperture 124, and can be secured by suitable fastening bolts 186. As can be seen in
The mandrel 142 includes one or more lubrication ports 158 that extend through the mandrel 142 to a point generally adjacent the bearing set 148. Once again, a suitable grease fitting 164 is provided. The mandrel 142 includes a first part 168 having a first diameter, and a second part 170 having a reduced diameter, and the bearing set 148 is mounted to the smaller second part 170. Preferably, an inner race 172 of the bearing set 148 may be mounted about the second part 170 using a bearing support 171, which may be a generally cylindrical sleeve or cup sized to fit over the second part 170. The bearing support 171 may be secured using suitable bolts 174. Still preferably, a seal 176 is mounted to the non-drive end 122 of the cylinder 112 and encircles the first part 168 of the mandrel 142. The seal 176 may be removable using a series of attachment bolts, screws or other suitable fasteners. A seal 178 may be connected to the drive side 116 of the cylinder 112 in a similar fashion.
Preferably, a lubrication port 188 extends generally axially through the drive shaft 128 to route lubrication toward the inner portion 138 of the driveshaft 128. The lubrication port 188 permits the splines 150, 152 in the bearing faces 180, 182 to be lubricated. A grease fitting 185 is carried by the driveshaft 128 and includes a port 188a that intersects the port 188.
A sidelay registration mechanism 190 includes an adjuster rod 191 connected to the bearing support 171. An outer end 192 of the adjuster rod extends from the outer end mandrel 142. The sidelay registration mechanism 190 is described in greater detail below with respect to
Referring now to
In operation, upon connecting the driveshaft 128 to a suitable power source as described above, it will be appreciated that rotation of the driveshaft 128 about its axis causes rotation of the cylinder 112 in a manner similar to that discussed above with respect to the first disclosed example. Once again, the cantilevered driveshaft 128 supports the drive end 120 of the cylinder. 112 at a point spaced inwardly along the axis A from the drive end 120, while the non-drive end 122 of the cylinder 112 is supported on the bearing set 148 carried by the inner portion 144 of the cantilevered mandrel 142, such that the non-drive end 122 of the cylinder 112 is supported at point space inwardly along the axis from the non-drive end 122.
Consequently, in accordance with the disclosed example, any deflection measured at a central portion of the cylinder 12 or 112 will be less than the measured deflection of a conventional cylinder having the same the same length measured from the drive end to the non-drive end, but having the conventional protruding shafts. For example, if the user desires a maximum deflection of the central portion 80 or 180 of the cylinders 12 or 112 to measure in the range of 1-2 thousandths of an inch, and the user knows the bending moment of inertia based on the cross section of the cylinder and the material properties of the cylinder, then the user can calculate how far inboard the support points need to be (measuring inboard from the ends of the cylinders toward the central portion of the cylinder) in order to ensure that the desired maximum deflection is not exceeded.
The present disclosure provides a method and apparatus for an improved method of supporting printing cylinders between the frames of a printing press. The present disclosure utilizes cylinder journals or supports which are not an integral part of the cylinder itself, but are rigidly mounted in the press frames. The cylinder supports are inserted into the cylinder to effectively shorten the cylinder span between the supports, and thus may improve the dynamic stability of the printing cylinders.
The present invention claims priority under 35 U.S.C. § 119(e) from U.S. Provisional Application Ser. No. 60/614,786, filed Sep. 29, 2004, the entire disclosure of which is incorporated herein.
Number | Date | Country | |
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60614786 | Sep 2004 | US |