摘要:
An extractor and a ventilation control window are coupled to the housing of a sheet delivery conveyor to extract unwanted heat, moisture, volatile vapors and obnoxious odors from the conveyor housing to eliminate the need for a separate venting system above the sheet delivery stacker. The suction airflow is varied by adjusting the speed of a vacuum source or motor driven fans, or by adjusting a ventilation window. A sheet control ventilation window is covered by a slidable, transparent panel which permits the operator to observe the orientation of the freshly printed sheets as the suction airflow is adjusted to precision. The sheet control window is also covered by a slidable screened panel which prevents introduction of objects into the press. Volatile vapors, moisture laden air and the like are also extracted from laterally opposite sides of the sheet delivery path, thus helping to control air turbulence at the delivery sheet stacker.
摘要:
A vacuum assisted sheet transfer assembly has an array of support bars which support the unprinted side of a freshly printed sheet along a sheet transfer path. The support bars overlie the airflow inlet of a manifold housing, with the longitudinal axis of each support bar extending across the sheet transfer path. The support bars provide smooth surfaces for engaging and supporting the unprinted side of the sheet material as it is pulled along the transfer path while simultaneously limiting the flow of inlet air through elongated inlet apertures. As air is drawn through the inlet apertures, the unprinted side of the sheet is sucked into engagement with the support bars as it moves along the sheet transfer path. The sheet transfer assembly eliminates the need for conventional skeleton wheels and the like. Marking, smearing and smudging are prevented since the printed side of the sheet is not handled or contacted in any way as the sheet is conveyed along the sheet transfer path.
摘要:
A vacuum transfer apparatus for use in a sheet fed rotary printing press for supporting the unprinted side of a freshly printed sheet as it is moved from the press impression cylinder along a transfer path to a further processing station of the press, the apparatus including a vacuum chamber supporting a plurality of rotatable elongated rollers arrayed in spaced side-by-side parallel relationship laterally across the transfer path, and a vacuum pump connected to the chamber for producing a pressure differential across the freshly printed sheet to draw the unprinted side of the sheet into engagement with the support rollers by drawing air into the vacuum chamber through the spaces between the rollers as the sheet is pulled along the transfer path so that the printed side of the sheet can not be marked or marred.
摘要:
In a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is provided. The anti-marking device comprises a flexible jacket having a first surface and a second surface, each surface having projections projecting from the surface. When the flexible jacket is installed over the transfer cylinder with the second surface positioned facing towards the transfer cylinder the first surface is positioned to engage the freshly printed substrate as it is transferred over the transfer cylinder, and when the flexible jacket is installed over the transfer cylinder with the first surface positioned facing towards the transfer cylinder the second surface is positioned to engage the freshly printed substrate as it is transferred over the transfer cylinder. The anti-marking device is removably attached to the transfer cylinder.
摘要:
In a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is provided. The anti-marking device comprises a flexible jacket comprised of fluoropolymer to engage the freshly printed substrate as it is transferred over the transfer cylinder, the anti-marking device removably attached with free play to the transfer cylinder. In an embodiment, a base cover is installed on the transfer cylinder between the anti-marking device and the transfer cylinder.
摘要:
In a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is provided. The anti-marking device comprises an assembly of at least two flexible jackets, the assembly removably attached with free play to the transfer cylinder, wherein an outermost flexible jacket supports the freshly printed substrate as it passes over the transfer cylinder and wherein the outermost flexible jacket is removable from the assembly while the assembly remains attached to the transfer cylinder. In an embodiment, a base cover is attached to the transfer cylinder, and the assembly is removably attached with free play to the transfer cylinder over the base cover.
摘要:
A flexible jacket covering for a printing press transfer cylinder having a low density selvage for attaching one edge of the jacket to a hook and loop attachment strip on the transfer cylinder. The covering is cut from fabric woven on a shuttleless loom. The fabric has a reduced density selvage formed by reducing the density of warp threads in the selvage is no more than the warp thread density in the body of the covering fabric and preferably to about half the warp thread density in the body of the fabric.
摘要:
A retractable in-line inking/coating apparatus selectively applies either spot or overall ink/coating to a blanket or flexographic plate on a blanket cylinder or spot coating or overall ink/coating to a flexographic printing plate on a plate cylinder in a rotary offset printing press. The inking/coating apparatus is pivotally mounted on the tower of a printing unit or dedicated coating unit, and is extended into and retracted out of inking/coating engagement by a carriage assembly which is pivotally coupled to the printing unit tower. Because of the pivotal support provided by a cantilevered support arm, the inking/coating apparatus can be raised and lowered through a Ferris wheel arc movement between adjacent printing units. The aqueous component of the printing ink or coating is evaporated by a high velocity, hot air interstation dryer and a high performance heat and moisture extractor so that the ink on a freshly printed sheet is dry before the sheet is printed on the next printing unit. Thus, flexographic ink or coating applied at the first printing unit can immediately be overprinted on subsequent printing units.
摘要:
A vacuum assisted sheet transfer assembly has an array of support bars which support the unprinted side of a freshly printed sheet along a sheet transfer path. The support bars overlie the airflow inlet of a manifold housing, with the longitudinal axis of each support bar extending across the sheet transfer path. The support bars provide smooth surfaces for engaging and supporting the unprinted side of the sheet material as it is pulled along the transfer path while simultaneously limiting the flow of inlet air through elongated inlet apertures. As air is drawn through the inlet apertures, the unprinted side of the sheet is sucked into engagement with the support bars as it moves along the sheet transfer path. The sheet transfer assembly eliminates the need for conventional skeleton wheels and the like. Marking, smearing and smudging are prevented since the printed side of the sheet is not handled or contacted in any way as the sheet is conveyed along the sheet transfer path.
摘要:
A coating apparatus for use in a sheet-fed or web-fed, offset rotary or flexographic printing press to apply a protective and/or decorative coating to the surface of freshly printed sheets includes a doctor blade coating unit coupled to a pickup roller for supplying liquid material from a reservoir to the surface of a pickup roller mounted on a press delivery drive shaft. Liquid material is circulated through the reservoir of the doctor blade unit by suction flow produced by a return pump. This prevents the buildup of a positive pressure differential within the doctor blade reservoir. The doctor blade reservoir is maintained at below ambient pressure level, thereby preventing leakage through the end seals. A vacuum sensor circuit provides a visual indication of air vacuum pressure in the doctor blade reservoir chamber, and a vacuum sensor switch applies electrical power to an audio transducer. The audio transducer produces an audible alarm in response to an increase in doctor blade chamber pressure, thereby providing advance warning of an impending end seal failure or a worn doctor blade condition.