Abstract:
Herein disclosed is a web paper cutting position adjusting system which comprises: marking means including a control unit for generating a predetermined phase detection signal by detecting a predetermined rotational phase of a platen, and a marking unit for marking a web paper in response to the predetermined phase detection signal; web paper cutting means disposed a predetermined distance downstream of the marking means for cutting the web paper; mark detecting means interposed between the marking means and the web paper cutting means for detecting the mark to transmit a mark detection signal; cutting phase signal transmitting means associated with the operation of the web paper cutting means for transmitting a cutting phase signal; and web paper threading path changing means including an arithmetic unit having an operation signal transmitting unit made receptive of the mark detection signal and the cutting phase signal for transmiting a web paper threading path length changing signal, if the transmission timing of the mark detection signal is outside of a predetermined range for allowance of the cutting phase signal, and a web paper threading path length changing unit disposed upstream of the mark detecting means for changing the threading path length of the web paper in response to the web paper threading path length changing signal.
Abstract:
A recorded image frame is distorted on the printing plate when image information or image data from a computer is recorded in the form of band strips, with a plurality of image elements dotted on each widthwise dotted line of the band, on a printing plate wound over a drum. The present invention permits an undistorted recording on the printing plate by an arrangement which includes a printing plate wound around a drum in the form of a right circular cylinder, an exposing assembly to record image information in the form of a band strip on the printing plate by means of light beam, a moving mechanism to move the exposing assembly in relation to the drum in the direction of the drum axis--by one band width per revolution of the drum--and a circuit to generate an incline distortion offsetting signal in a sawtoothed pattern having the cycle synchronized with that of the rotation of the drum with the initial writing position on the band as starting point. Under this arrangement, this incline distortion offsetting signal is applied to the exposing assembly to gradually move the light beam in the direction opposite to the moving direction of moving mechanism--by one band width per revolution of the drum. This process is repeated until the whole printing image is recorded.
Abstract:
A system for making printing plates for newspaper, which can make, with great efficiency, replacement printing plates to be used when a printing face of the printing plate mounted on the plate cylinder of the rotary press is to be changed in part. The plate-making system is built by linearly arranging in series a plate feeder 2, an exposure unit 3, and a developer 5 so that the exposure unit 3 may directly form images on the printing faces of a plate material 12 in accordance with image drawing signals from a computer to make a printing plate P large enough for at least several pages. On the downstream side of the developer 5 are provided: a borer 7 for making positioning notches 12a and positioning holes 12b in the plate material 12 (for several pages of newspaper) as discharged from the developer 5; a cutter 12 for cutting the plate material 12 (for several pages of newspaper) from the borer 7 into several plate materials 12', each the size one page of newspaper; a first bender for forming bends 12c, for mounting the printing plate on the rotary press, in the plate material 12 (for several pages of newspaper) which plate material has not been cut by the cutter 8 after being bored by the borer 7; and a second bender for forming bends 12c, for mounting the printing plate on the rotary press, in several one page size plate materials 12' which have been obtained by cutting the plate material 12 by the cutter 8 after boring by the borer 7.
Abstract:
A dampening system for a printing apparatus includes a print plate, a printing cylinder contacting the print plate and adapted to supply water to the print plate, a feed device for feeding water to the printing cylinder, and a dampening roller adapted to transfer water from the feed means to the printing cylinder. The dampening roller comprises a roller having a dampening layer composed of a substrate through which is dispersed a plurality of minute hollow bodies. A plurality of the hollow bodies open towards the circumferential surface to form cells for transferring the water from the feed means to the printing cylinder. At least one of the size and the concentration of the hollow bodies dispersed within the substrate is selected depending on the amount of dampening water to be fed to the print plate.
Abstract:
A color printing apparatus printing for both sides of a web of printing paper comprises a plurality of printing sections which are arranged at a regular interval in a piled configuration. Each one of the printing section includes a pair of blanket cylinders facing each other which can be moved between their contacting positions and their isolating position. Every blanket cylinder is connected to a plate cylinder which is connected to an inking unit, or an inking unit and a dampening unit. Each of the plate cylinders is further provided with a fine adjusting means for shifting the plate cylinder along its axis with respect to the blanket cylinder. The shifting operation of the fine adjusting means can easily minimize the printing shears caused by moisture without stopping the printing apparatus.
Abstract:
The present invention has as an object to provide an inking device which prevents the generation of vibration in rollers and is capable of supplying the amount of ink uniformly all the time to the surface of printing plate in the direction of its width. The inking device of the invention is constructed such that the distance between the bottom of the ink pan and the surface of the ink fountain roller, the distance between the surface of the ink fountain roller and the surface of the ink transfer roller and the surface of the roller next to it in the downstream direction are made smaller as the distance proceeds downstream. The ink is transferred from the upstream side to the downstream side, and during this ink transfer, the ink distribution is regulated uniformly in the direction of roller width by means of a doctor blade, etc. Further, the circumferential surface speeds of the rollers are variable, and the vibration of the inking device is prevented by matching the circumferential surface speed of the ink transfer roller to the circumferential surface speeds of the rotating rollers on the downstream side.
Abstract:
A roller with a doctor blade has both a harder material portion and a softer material portion provided on the peripheral surface in the same radius from the center of the roller, for achieving complete doctoring. The harder material portion forms a minimum belt-like line in a non-perpendicular direction with respect to the axis of the roller, and preventing wear by doctoring against the softer material portion, and limits the wear of the doctor blade, producing uniform wear without a fear of local wear. The softer material portion has maximum area provided between the turns of the belt-like line and facilitates the formation of cells for measuring and the use of a lipophilic material.
Abstract:
A groove having parallel walls is formed in the longitudinal direction of a blanket cylinder.A pair of retainers are attached to and along both ends of a blanket. The opposing end surfaces of the pair of retainers have alternating convexities and concavities arranged to permit the opposing surfaces to slide up and down relatively to each other. The total width of the pair of retainers with the convexities and concavities mating with each other coincides with the width of the groove. The pair of retainers are guided by the walls of the groove such that each retainer can be moved up and down along the associated wall independently of each other as a plurality of tensioning bolts are tightened or loosened.Whereby, the tension can be applied only to the portion of the blanket which tends to be slack, in response to the change of the slacking portion due to the change of direction of rotation of the blanket cylinder, while applying no tension to the portion of the blanket irrespective of the direction of rotation to the portion of the blanket which is in close and good contact with the blanket cylinder to preserve the good contacting condition.