Abstract:
In a rotary stencil printing press including a rotary screen cylinder which supports a screen printing forme and is supported rotatably, and a squeegee which is located within the rotary screen cylinder and, when printing is done, contacts an inner peripheral surface of the screen printing forme to transfer ink stored within the rotary screen cylinder to a web via holes of the screen printing forme and, when printing is stopped, leaves the inner peripheral surface of the screen printing forme, throw-on and throw-off of the squeegee with respect to the inner peripheral surface of the screen printing forme, and adjustment of the position of the throw-on are performed by motors.
Abstract:
In a rotary screen device in which ink is transferred through holes of a screen, with a rotary screen cylinder provided with the screen being rotated, to carry out printing, the rotary screen cylinder is stopped, in accordance with a stop signal, at a position at which a pattern-free portion (a hole-free portion) of the screen comes to a lowermost position. Since the rotation of a stencil printing press is stopped in a rotation phase in which the pattern-free portion of the screen comes to the lowermost position, ink is prevented from dripping through the holes of the screen.
Abstract:
A pile board inserting machine comprises two pile board inserting units installed in combination respectively with the two sheet piling units of a sheet-fed printing press. Printed sheet are delivered alternately to the two pile board inserting units every time a predetermined number of printed sheets are delivered to each sheet piling unit, and the pile board inserting unit associated with the inoperative sheet piling unit is operated to insert a pile board while the sheet piling unit is at rest. Each pile board inserting unit comprises a lifting bar for lifting stacked pile boards, a pile board inserting mechanism for pushing the top pile board into the sheet piling unit, a lower limit detecting switch for detecting the arrival of the lifting bard at a lowermost position, an automatic start switch which starts lifting bar raising operation only when the lower limit detecting switch is closed, warning means which provides an alarm upon the reduction of the number of pile boards on the lifting bars to a predetermined number, and stopping means for stopping the printing press after the duration of the alarm has exceeded a predetermined time. The pile board is inserted automatically into the sheet piling unit, and the operator is warned of the reduction of the pile board on the lifting bars by the alarm.
Abstract:
In a sheet-fed printing press including; an impression cylinder gear driven by an upstream drive motor of an upstream printing unit group; an impression cylinder rotationally driven by the impression cylinder gear; a transfer cylinder gear of a convertible press mechanism rotationally driven by the upstream drive motor through the impression cylinder; and a transfer cylinder which is provided with a notch and is rotationally driven by the transfer cylinder gear, a load motor is provided to the transfer cylinder or the transfer cylinder gear, and braking force of the load motor is controlled according to load on the upstream drive motor.
Abstract:
A method and a device for synchronously controlling multiple printing presses or multiple units in a printing press can reduce power consumption and improve durability of motors and motor bearings. A synchronous control device for multiple printing presses includes machine shafts of a main printing press and a sub printing press respectively provided with drive motors and is configured to synchronously control rotation of the sub printing press with respect to rotation of the main printing press. Here, drive motor brakes are attached to the respective drive motors, and drive control devices respectively configured to release synchronous control of the drive motor of the sub printing press by a stop instruction and to start the drive motor brakes of both of the printing presses are provided.
Abstract:
A rotary screen printing press includes a rotary screen cylinder which supports a screen printing forme and is supported rotatably; an impression cylinder which is provided to oppose the rotary screen cylinder, has a groove portion provided in an outer peripheral surface thereof, the groove portion accommodating a gripper device for holding a material to be printed, and is supported rotatably; and a squeegee which is located within the rotary screen cylinder and, during printing, contacts an inner peripheral surface of the screen printing forme, while being pressed against it, to transfer ink stored within the rotary screen cylinder to the material to be printed, which is held on the impression cylinder, via holes of the screen printing forme. The printing press has a squeegee throw-on and throw-off control device which, when the squeegee opposes the groove portion of the impression cylinder, brings the squeegee into contact with the inner peripheral surface of the screen printing forme, and controls the pressing force of the squeegee acting on the inner peripheral surface of the screen printing forme to be lower than its pressing force exerted during printing.
Abstract:
Provided are an ink supply amount adjustment method and system for a relief printing press which enable a reduction in a burden of the operator by enabling automatic adjustment of an ink fountain key opening degree and an ink fountain roller rotation speed on the basis of the width or the area of a line portion measured in advance, and a reduction in costs by reducing the amount of waste paper to be produced, the relief printing press including: an ink fountain for storing ink; and ink fountain keys and an ink fountain roller for adjusting the amount of ink supplied from the ink fountain. The width of a line portion printed on paper by the relief printing press is measured by a width measuring camera, and the ink fountain key opening degrees and the ink fountain roller rotation speed are controlled on the basis of the obtained line-portion width.
Abstract:
A printing quality control method and apparatus are disclosed for a printing press including an ink fountain for storing ink, and a motor for driving an ink fountain roller which adjusts the amount of ink supplied from the ink fountain. According to the method and apparatus, a face side distance measuring instrument measures the ink film thickness of a printing product of printing by the printing press, and control means controls the motor for driving the ink fountain roller based on the ink film thickness measured.
Abstract:
An ink feed control method for a printing press in which ink, supplied to an ink fountain roller from a gap between each ink fountain key and the ink fountain roller by the rotation of the ink fountain roller, is supplied to the printing plate by swing operation of an ink ductor roller, so that a print is eventually made on a print sheet with the ink supplied to the printing plate, the method including the steps of: measuring any one of the density and the ink film thickness of a first printing product made by the printing press; and controlling the number of times of the swing operation of the ink ductor roller relative to the rotation of the printing press in accordance with the value of the measured one of the density and the ink film thickness of the first printing product.
Abstract:
A printing press includes, a printing unit; a motor for driving the printing unit; a first drive system for drivingly connecting a blanketed impression cylinder, etc. of the printing unit to the motor; a first frame cover for covering the first drive system; an inker movable to be capable of being thrown on and thrown off the printing unit; a second drive system for driving ink rollers of the inker; and a second frame cover for covering the second drive system, the printing press further includes a motor for driving the ink rollers of the inker via the second drive system, and wherein opposed surfaces of the first frame cover and the second frame cover are entirely closed.