Abstract: A blanket that has a varying profile and a method for its use is disclosed. By varying the profile of the blanket cylinder and/or blanket, either in terms of its material properties or its thickness, the blanket, when placed about a blanket cylinder, corrects for unwanted variation in the velocity profile present in the web. Such velocity profile variations, if not taken into account, may cause wrinkling of a web passing over the blanket cylinder in a printing press and thus cause misregistered images. In a further embodiment, the blanket cylinder may be provided with a varying profile.

Abstract: A blanket that has a varying profile and a method for its use is disclosed. By varying the profile of the blanket cylinder and/or blanket, either in terms of its material properties or its thickness, the blanket, when placed about a blanket cylinder, corrects for unwanted variation in the velocity profile present in the web. Such velocity profile variations, if not taken into account, may cause wrinkling of a web passing over the blanket cylinder in a printing press and thus cause misregistered images. In a further embodiment, the blanket cylinder may be provided with a varying profile.

Abstract: A tubular printing blanket for a blanket cylinder in an offset printing press comprises a cylindrical sleeve, a compressible layer over the sleeve, and an inextensible layer over the compressible layer. The cylindrical sleeve is movable telescopically over a blanket cylinder. The compressible layer comprises a first seamless tubular body of elastomeric material containing compressible microspheres. The inextensible layer comprises a second seamless tubular body of elastomeric material containing a tubular sublayer of circumferentially inextensible material. A seamless tubular printing layer over the inextensible layer has a continuous, gapless cylindrical printing surface. Methods of manufacturing the tubular printing blanket are also disclosed.

Abstract: An apparatus for reducing procession of a gapless tubular printing sleeve in an offset printing press caused by at least one fluid wave having a certain pressure trapped at an interface of the printing sleeve and a cylinder on which it is mounted. The apparatus includes a cylinder which is adapted to receive the printing sleeve for mounting on its circumferential surface. The cylinder has at least one path which connects an interface of the cylinder and the printing sleeve to a region of pressure lower than the pressure in the fluid wave. The path allows the fluid wave, which is trapped at the interface and advancing in front of a nip between the cylinder and an adjacent cylinder, to escape to the region of low pressure.

Abstract: A tubular printing blanket for a blanket cylinder in an offset printing press comprises a cylindrical sleeve, a compressible layer over the sleeve, and an inextensible layer over the compressible layer. The cylindrical sleeve is movable telescopically over a blanket cylinder. The compressible layer comprises a first seamless tubular body of elastomeric material containing compressible microspheres. The inextensible layer comprises a second seamless tubular body of elastomeric material containing a tubular sublayer of circumferentially inextensible material. A seamless tubular printing layer over the inextensible layer has a continuous, gapless cylindrical printing surface. Methods of manufacturing the tubular printing blanket are also disclosed.

Abstract: In a lithographic printing press for printing on material in sheet or web form, a plate cylinder has a printing form mounted thereon. A gapless blanket cylinder is engageable with the plate cylinder and a tubular, removable blanket having a continuous surface is mounted on the blanket cylinder. Mechanisms to expand a cylindrical sleeve are provided as well as mechanisms to reduce cylinder distortion during rotation.

Abstract: A tubular printing blanket for a blanket cylinder in an offset printing press comprises a cylindrical sleeve, a compressible layer over the sleeve, and an inextensible layer over the compressible layer. The cylindrical sleeve is movable telescopically over a blanket cylinder. The compressible layer comprises a first seamless tubular body of elastomeric material containing compressible microspheres. The inextensible layer comprises a second seamless tubular body of elastomeric material containing a tubular sublayer of circumferentially inextensible material. A seamless tubular printing layer over the inextensible layer has a continuous, gapless cylindrical printing surface. Methods of manufacturing the tubular printing blanket are also disclosed.

Abstract: An improved printing press includes a tubular-shaped printing blanket removably disposed on a blanket cylinder rotatably supported by a frame and having a continuous outer circumferential surface which is free of gaps. The printing blanket is disposed in rolling engagement with a conventional printing plate disposed on a plate cylinder having an axially extending gap in which opposite ends of the printing plate are secured. The printing blanket is removed by opening a portion of the frame and axially sliding the printing blanket off of the blanket cylinder. To assist in the removal or insertion of the printing blanket the blanket cylinder has passages which deliver a stream of air to the outer surface of the blanket cylinder which expands the inner circumferential surface of the printing blanket so that the blanket can be axially removed or inserted onto the blanket cylinder.

Abstract: A tubular printing blanket for a blanket cylinder in an offset printing press comprises a cylindrical sleeve, a compressible layer over the sleeve, and an inextensible layer over the compressible layer. The cylindrical sleeve is movable telescopically over a blanket cylinder. The compressible layer comprises a first seamless tubular body of elastomeric material containing compressible microspheres. The inextensible layer comprises a second seamless tubular body of elastomeric material containing a tubular sublayer of circumferentially inextensible material. A seamless tubular printing layer over the inextensible layer has a continuous, gapless cylindrical printing surface. Methods of manufacturing the tubular printing blanket are also disclosed.

Abstract: A tubular printing blanket for a blanket cylinder in an offset printing press includes a cylindrical sleeve, a compressible layer over the sleeve, and an inextensible layer over the compressible layer. The cylindrical sleeve is movable telescopically over a blanket cylinder. The compressible layer includes a first seamless tubular body of elastomeric material containing compressible microspheres. The inextensible layer includes a second seamless tubular body of elastomeric material containing a tubular sublayer of circumferentially inextensible material. A seamless tubular printing layer over the inextensible layer has a continuous, gapless cylindrical printing surface. Methods of manufacturing the tubular printing blanket are also disclosed.

Abstract: An offset printing unit (10) for printing an inked image on sheet material (30) comprises a rotatable plate cylinder (12) and a rotatable blanket cylinder (14). The plate cylinder (12) supports a printing plate (18) which defines the inked image. A tubular printing blanket (20) is received telescopically over the blanket cylinder (14). The printing unit (10) further comprises a frame (16) and a motor (26). The frame (16) supports the plate cylinder (12) and the blanket cylinder (14) in positions for the printing plate (18) to transfer the inked image onto the tubular printing blanket (20) at a nip (28) between the cylinders (12, 14) when the cylinders (12, 14) are rotating. The motor (26) rotates the plate cylinder (12) and the blanket cylinder (14) to transfer the inked image to the tubular printing blanket (20).

Abstract: A printing unit (10) includes a blanket cylinder (20), a bearing assembly (56) and a door assembly (72). The blanket cylinder (20) carries a tubular printing blanket (36). The bearing assembly (56) includes a bearing housing (58) fixed to the stub shaft (50) on the end of the blanket cylinder (20). The door assembly (72) includes a door (82) which is supported for pivotal movement on a frame wall (22) of the printing unit (10). The door (82) has a closed position in which it extends across an opening (76) in the frame wall (22), and an open position in which it does not extend across the opening (76) in the frame wall (22). A clamping assembly clamps the bearing housing (58) on the door (82) when the blanket cylinder (20) rotates during a printing operation. The clamping assembly includes a first clamp (100) which fixed to the door (82) and a second clamp (102) which is supported on the door (82) for movement relative to the first clamp (100).

Abstract: A tubular printing blanket (20) has a metal sleeve (42) which is receivable over a blanket cylinder (14) in an offset printing unit (10). The sleeve (42) is expandable diametrically under the influence of pneumatic pressure directed against the inner surface (46) of the sleeve (42), and is movable telescopically over the blanket cylinder (14) when in its expanded condition. The tubular printing blanket (20) has a damping ring (120) for attenuating noise upon expansion of the sleeve (42) under the influence of the pressurized flow of air. The damping ring (120) damps vibrations of the sleeve (42) which are caused by the pressurized flow of air, and which cause noise.

Abstract: A printing unit (10) includes a blanket cylinder (20), a bearing assembly (56) and a door assembly (72). The blanket cylinder (20) carries a tubular printing blanket (36). The bearing assembly (56) includes a bearing housing (58) fixed to the stub shaft (50) on the end of the blanket cylinder (20). The door assembly (72) includes a door (82) which is supported for pivotal movement on a frame wall (22) of the printing unit (10). The door (82) has a closed position in which it extends across an opening (76) in the frame wall (22), and an open position in which it does not extend across the opening (76) in the frame wall (22). A clamping assembly clamps the bearing housing (58) on the door (82) when the blanket cylinder (20) rotates during a printing operation. The clamping assembly includes a first clamp (100) which fixed to the door (82) and a second clamp (102) which is supported on the door (82) for movement relative to the first clamp (100).