| 摘要 |
A pneumatic axially oscillated, frictionally rotated roller is disclosed and may be used in the ink or damping systems of a printing press. The roller features an internal air piston-cylinder construction that causes the axial motion but permits the roller to freely rotate. Further, several air cylinders can be stacked on each side of the roller to permit even a small diameter roller to be pneumatically oscillated. The roller, when used as an ink form roller, may be operated to oscillate in synchronization with an adjacent oscillating, vibrating roller to continually diagonally redistribute the ink so as to eliminate or minimize "ghosting". The foregoing is accomplished by controlling the oscillation of the form roller to move axially in a direction opposite of that of the vibrating roller. The lengths of the strokes of the two rollers may differ or be the same. The length of axial movement or stroke of the form roller can be varied, while maintaining synchronization by varying the speed of the axial motion, a slower speed yielding a shorter stroke and a higher speed yielding a longer stroke for a given half cycle.
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