Printing – Processes – Condition responsive
Reexamination Certificate
2002-03-21
2004-02-03
Hirshfeld, Andrew H. (Department: 2854)
Printing
Processes
Condition responsive
C318S700000, C700S003000
Reexamination Certificate
active
06684788
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from Japanese patent application Serial no. 2001-177895 filed Jun. 13, 2001, the contents of which are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a control system for a rotary press, and more particularly to a control system for the so-called shaft-less rotary press that carries out printing operation by separately driving the driven components thereof, such as a printing section and a folding section, with independent motors; the control system capable of decelerating the driven components at least in synchronization with each other, and stopping them in the event of a main power failure.
2. Description of the Related Art
Conventional rotary presses, such as disclosed in Japanese Published Examined Patent Application No. Sho-60(1985)-36946, employ an integrated drive source comprising a plurality of main motors provided on a printing section, a folding section and other components of the rotary press connected to each other via a main shaft and a clutch to drive the entire rotary press system.
In recent years, on the other hand, the so-called shaft-less rotary press has become widely used due to various advantages in printing operation. In the shaft-less rotary press, a plurality of motors separately drive different driven components, with electrical synchronous control maintained so that the rotational speed and phase of the motors and the driven components can be properly matched with each other, as disclosed in Japanese Patent Publication Nos. 3037650 and 3059081.
With the shaft-less rotary press, however, the motors and the driven components tend to keep rotating by reason of inertia in case power feeding is interrupted due to a main supply failure during printing. This could lead not only to improper printing results but also to uneven tension on the paper web traveling in the rotary press, resulting in the breakage of the web or the clinging of the web around the rotary parts in extreme cases.
Restoration of the rotary press to the normal printing state, such as removal of the paper clung to the rotary parts, or rethreading of the web to the normal travel path, would take much time, preventing printing operation from being immediately resumed even after power supply has been returned to normal. This has been a big problem to be solved especially in newspaper printing and other printing operations requiring quick and timely printing.
As a measure to solve this problem, the shaft-less rotary press disclosed in Japanese Patent Publication No. 3037650 employs a construction where driven components are individually braked to stop the rotary press in case power feeding is interrupted due to a main power failure.
This rotary press control method, however, tends to have differences in the inertial forces that cause the driven components to keep rolling even after power feeding has been interrupted, and there are no small differences in braking forces to put brake on the rotation caused by the inertial forces. In addition, there is some time lag in the timing at which braking is started in each braking section. All these factors have caused variability in the time required for the rotating speed of each driven component to begin decreasing due to braking as well as in the time required for each driven component to come to a halt. For this reason, even this type of rotary press could not avoid uneven tensions on the traveling paper web in the rotary press that could lead to the breakage of the web or the clinging of the web around the rotary parts.
SUMMARY OF THE INVENTION
The present invention is intended to overcome the aforementioned problems, and it is therefore an object of the present invention to provide a rotary press control system, specifically for electrically synchronous-controlled shaft-less rotary presses, that is capable of control in the event of a power failure by preventing uneven tensions from exerting on a continuous paper web that travels in the rotary press, thereby preventing the paper web from breaking or sticking to the rotary parts, so that printing operation can be resumed immediately after the main power is restored.
The present invention provides a rotary press control apparatus capable of controlling, in the event of a power failure, the operation of a rotary press comprising at least one unit each of printing and folding sections; each of the printing and folding sections having at least one electric motor so as to be driven individually, the rotary press operated in a synchronized manner by the motors; the apparatus comprising: an inverter provided on each motor for controlling the rotation of the motor; a basic command output section that can be operated even in a power failure for outputting a normal operation basic speed command signal during normal operation, and a power failure basic speed command signal and a power failure basic voltage command signal for specifying the voltage of power fed to the inverter in the event of a power failure; a power failure detecting section for detecting a power failure and outputting a power failure signal; a power failure power feeding section for storing the power generated by the inertial rotation of the motors during a power failure where the power failure detecting section detects the power failure and feeding power to each of the inverters; and a control command output section that can be operated even in a power failure for outputting a normal operation control speed command signal in accordance with the normal operation basic speed command signal during normal operation, and in the event of a power failure where the power failure detecting section detects the power failure, comparing the power failure basic voltage command signal with an output voltage detection signal of the power failure power feeding section, and generating a power failure control speed command signal for output by correcting the power failure basic speed command signal in accordance with the comparison results, so that the rotary press can be decelerated and stopped at least in a synchronized state in the event of a power failure while stabilizing the voltage of the power fed to each of the inverters from the power failure power feeding section to a voltage level instructed by the power failure basic voltage command signal.
The present invention provides a rotary press control method capable of controlling, in the event of a power failure, the operation of a rotary press comprising at least one unit each of printing and folding sections; each of the printing and folding sections having at least one electric motor so as to be driven individually, and an inverter provided on each motor for controlling the rotation of the motor; the rotary press operated in a synchronized manner by the motors, the method comprising: a basic command output process that can be operated even in a power failure for outputting a normal operation basic speed command signal during normal operation, and a power failure basic speed command signal and a power failure basic voltage command signal for specifying the voltage of power fed to the inverter in the event of a power failure; a power failure detecting process for detecting a power failure and outputting a power failure signal; a power failure power feeding process for storing the power generated by the inertial rotation of the motors during a power failure where the power failure detecting process detects the power failure and feeding power to each of the inverters; and a control command output process that can be operated even in a power failure for outputting a normal operation control speed command signal in accordance with the normal operation basic speed command signal during normal operation, and in the event of a power failure where the power failure detecting process detects the power failure, comparing the power failure basic voltage command signal with an output voltage detection signal of the power failure power feeding process, and g
Kaneko Ryoji
Ohno Kinichiroh
Hirshfeld Andrew H.
Nguyen Hoai-An D.
Tokyo Kikai Seisakusho Ltd.
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