Printing – Rolling contact machines – Rotary
Reexamination Certificate
2000-07-10
2002-07-16
Yan, Ren (Department: 2854)
Printing
Rolling contact machines
Rotary
C101S375000, C492S047000
Reexamination Certificate
active
06418845
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a printing cylinder for offset printing which is removably attached onto a printing machine.
2. Description of the Related Art
Japanese Patent No. 2825784 and Japanese Patent Application Laid-Open (kokai) No. 7-256864 disclose examples of a conventional printing cylinder for offset printing which is removably attached onto a printing machine. Further, Japanese Patent Application Laid-Open (kokai) No. 1-242250 discloses a conventional printing cylinder for gravure printing which is removably attached onto a printing machine.
The printing cylinder disclosed in Japanese Patent No. 2825784 consists of a cylinder body, an endless rubber blanket attached to the outer circumferential surface of the cylinder body, and bearing journals connected to the opposite ends of the cylinder body. The bearing journals are attached to opposed frames such that the flanges of the bearing journals face each other while sharing a common center axis. Each of the flanges of the bearing journals can be moved toward the corresponding frame, so that the distance between the flanges becomes slightly greater than the axial length of the printing cylinder.
The printing cylinder has a centering/release apparatus provided with the cylinder body. Specifically, stopper disks are disposed within and fixed to a through hole which extends in the axial direction of the cylinder body. A pin having a tip end of a truncated conical shape is disposed between each of the stopper disks and the inner surface of the flange of the corresponding bearing journal such that the pin is movable in the axial direction only. On the inner surface of the flange of each bearing journal is formed a tapered circular depression for receiving the tip end of the corresponding pin.
An adjustment bolt is inserted into each stopper disk such that the head portion of the adjustment bolt is in contact with the stopper disk, whereby axial movement of the adjustment bolt toward the corresponding pin is restricted. The tip end of the adjustment bolt is screwed into a through hole of the pin, and a compression spring is disposed between the stopper disk and the inner end surface of the pin. Further, a manipulation hole is formed in each bearing journal such that the manipulation hole is aligned with the through hole of the pin.
A tool inserted into the manipulation hole of the bearing journal and further into the through hole of the pin is engaged with a depression formed on the tip end surface of the adjustment bolt. Subsequently, the tool is rotated in order to rotate the adjustment bolt to thereby advance or retract the pin in the axial direction. Through this axial movement of the pin, the engagement between the truncated-conical tip end of the pin and the tapered depression in the inner surface of the bearing journal is established or broken.
The adjustment bolt may be rotated by use a motor which is disposed within the printing cylinder and has a motor shaft connected to the adjustment bolt.
The printing cylinder is attached onto the printing machine as follows. First, in a state in which the pins are retracted into the cylinder body, the cylinder body is placed between the opposed flanges of the bearing journals, and the pins are projected from the cylinder body and fitted into the tapered depressions of the flanges. Subsequently, the flanges are fixed to the opposed end surfaces of the cylinder body by use of bolts.
The patent publication discloses another mechanism for advancing and retracting pins. Only a compression spring is disposed within the through hole of the cylinder body in order to bias the pins such that their tip ends project from the opposite end surfaces of the cylinder body. A pressure chamber is formed between each pin and the cylinder body. When a pressurized medium is supplied to the pressure chamber, the pressure chamber expands axially, so that the pin is retracted into the cylinder body against the restoration force of the spring.
The printing cylinder disclosed in Japanese Patent Application Laid-Open No. 7-256864 can be used as a plate cylinder and a blanket cylinder. The printing cylinder consists of a cylindrical cylinder body, a shaft attached to one end of the cylinder body such that the center axis of the shaft is aligned with that of the cylinder body, and a tapered circular depression formed on the opposite end of the cylinder body such that the center axis of the depression is aligned with that of the cylinder body. Further, a groove is formed on the outer circumferential surface of the cylinder body such that the groove extends parallel to the center axis of the cylinder body to reach the opposite end surfaces. The groove can accommodate opposite end portions of a form plate or blanket. Alternatively, the groove can accommodate therein a winding shaft for winding the opposite end portions.
The printing cylinder is attached onto a printing machine by use of printing cylinder support means provided on the printing machine.
The printing cylinder support means includes opposed first and second frames, the first frame having an opening through which a printing cylinder is loaded; a sub-frame disposed on the outer side of the opening of the first frame to be movable along the side surface of the first frame and adapted to support a shaft provided at a first end of the printing cylinder; and a support shaft which is supported on the second frame such that the center axis of the support shaft is aligned with the printing cylinder support position of the sub-frame and which is adapted to be fitted into a tapered circular depression provided at the second end of the printing cylinder to thereby support the second end of the printing cylinder.
The printing cylinder is attached onto the printing machine as follows. The printing cylinder is loaded via the opening of the first frame and is positioned such that the truncated conical tip end of the support shaft provided on the second frame is fitted into the tapered circular depression provided at the second end of the printing cylinder. Subsequently, the sub-frame disposed on the outer side of the first frame having the opening is moved so as to close the frame opening. As a result, the sub-frame comes into contact with the shaft at the first end of the printing cylinder to thereby support the shaft.
The printing cylinder disclosed in Japanese Patent Application Laid-Open No. 1-242250 is used as a plate cylinder. The printing cylinder has a cylindrical shape, and a tapered circular depression is formed on each of the opposite ends of the printing cylinder such that the center axes of the tapered circular depressions are aligned with each other. Further, a key groove is formed in one of the tapered circular depressions.
The printing cylinder is supported by printing cylinder support means provided on the printing machine.
The printing cylinder support means consists of two support shafts which are supported on opposed drive-side and manipulation-side frames such that the support shafts are rotatable about a common center axis and are axially movable; two moving mechanisms for moving the respective support shafts in the axial direction; a drive transmission mechanism disposed on the drive-side frame and adapted to transmit rotation to the drive-side support shaft; and a constant phase stop mechanism for stopping the drive-side support shaft at a preset angular position in the circumferential direction.
Each of the two support shafts for supporting the printing cylinder has a truncated conical tip end, which is fitted into a tapered circular depression formed on the corresponding end surface of the printing cylinder. Further, at the tip end of the drive-side support shaft is attached a key which is to be fitted into the key groove provided in the corresponding tapered circular depression of the printing cylinder.
The moving mechanism for moving the drive-side support shaft includes a bearing sleeve which is disposed on the drive-side frame to be movable in the axial direction and which ro
Kawashima Shinji
Satoh Masayoshi
Tokyo Kikai Seisakusho Ltd.
Yan Ren
LandOfFree
Printing cylinder for offset printing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Printing cylinder for offset printing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Printing cylinder for offset printing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2850218