Printing – Inkers – Roller
Reexamination Certificate
1999-07-09
2001-01-30
Asher, Kimberly (Department: 2854)
Printing
Inkers
Roller
C101S351400, C101S364000, C101S352030, C101S352050
Reexamination Certificate
active
06178887
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention deals with means including an ink fountain and forming parts of an inking mechanism for printing presses, particularly those having a printing plate wrapped around a plate cylinder. More particularly, the invention concerns ink supply means suitable for “keyless” printing, by which is meant the printing processes that demand no control of ink supply to suit specific density distributions as required by the images on the printing plates but that need only ink film of constant thickness at all times.
Japanese Unexamined Patent Publication No. 9-226095 is hereby cited as teaching an ink supply apparatus closest to the instant invention. This prior art apparatus includes an ink fountain having an open side closed by a fountain roller, which is therefore constantly directly exposed to the ink in the fountain. The ink is transferred from the fountain roller to a knurled cylinder via one or more ink rollers, from which knurled cylinder excess ink is doctored off and back into the ink fountain. Ink transfer from the knurled cylinder to the printing plate on a plate cylinder is accomplished, typically, by two ink rollers each in rolling contact with both knurled cylinder and plate cylinder. Ideally, the ink film thus formed on the plate cylinder is of constant thickness throughout its axial dimension.
Further, according to the prior art, the ink fountain has its bottom formed, either in part or in whole, by a blade movable into and out of abutment against the surface of the fountain roller to close and open the ink outlet therebetween. Drive means are mounted to the ink fountain for linearly moving the blade toward and away from the fountain roller.
Difficulties have been experienced, however, in moving the fountain bottom blade into neat, leak-free contact with the fountain roller, particularly in usual cases where the blade, and of course the fountain roller as well, are elongated axially of the fountain roller. In such cases there have been provided two or more drive mechanisms in spaced positions along the fountain roller axis. The noted prior art teaches the use of drive mechanisms that are independently adjustable for moving the blade parallel to the fountain roller. Such adjustable drive mechanisms are complex and costly in construction, inherently susceptible to troubles and malfunctionings because of precise synchronization sought after, and have required much time and labor for repair and maintenance.
As an additional disadvantage, even when themselves functioning normally, the drive mechanisms have been easy to cause uneven travel of the blade due to differences in load thereon. Ink has often leaked from between the blade and the fountain roller when, with the cessation of printing operation, the former is forced into contact with the latter because of nonparallel relationship therebetween.
SUMMARY OF THE INVENTION
The present invention seeks to accomplish, in ink supply apparatus of the kind defined, leak-free contact between blade and fountain roller by use of means that are materially simplified, inexpensive, and maintenance-free in construction and positive and reliable in operation.
Briefly, the invention may be summarized as an ink supply apparatus comprising an ink fountain for containing ink, and a fountain roller closing one side of the ink fountain and constantly exposed to the ink. Forming at least part of the fountain bottom, a blade means is provided which are movable toward and away from the surface of the fountain roller for closing and opening an ink outlet defined by and between the fountain roller and the blade means. The blade means is resiliently biased away from the fountain roller. A plurality of blade drive means are disposed in spaced positions along the fountain roller axis and act between the ink fountain and the blade means for moving the blade means into engagement with the surface of the fountain roller against the force of the resilient means in order to close the ink outlet. A link means is provided for mechanically linking the blade drive means to each other in order to synchronize the operations thereof and hence to assure leak-free contact of the blade means with the fountain roller.
The mechanical linking of the two or more blade drive means constitutes perhaps the most pronounced feature of the instant invention. Since a simple straight link is the easiest, cheapest, and most reliable way of linking, it is considered desirable that the blade drive means include linear actuators that are aligned parallel to the fountain roller axis, the aligned output members of such actuators being capable of rigid interconnection by a straight link.
Thus, in a preferred embodiment of the invention, each of two identical blade drive means is comprised of a blade pusher coupled to the blade means and constrained to linear travel with the blade means toward and away from the fountain roller, a linear actuator mounted to the ink fountain and having an output member reciprocably movable relative to the ink fountain in a direction parallel to the axis of the fountain roller, and cam means for translating the motion of the output member of the linear actuator in the direction parallel to the axis of the fountain roller into the motion of the blade pusher at right angles with the axis of the fountain roller. The output members of both linear actuators are interconnected by a straight link.
Most desirably, the linear actuators take the form,of double-ended-rod fluid actuators each comprising a double-ended rod immovably mounted to the ink fountain, a piston formed on the double-ended rod, and a cylinder slidably fitted over the piston so as to define a pair of fluid chambers on opposite sides of the piston, the cylinder being capable of linear reciprocation relative to the ink fountain in a direction parallel to the axis of the fountain roller. It is therefore the cylinders, not the double-ended piston rods, that constitute the output members of these fluid actuators. Both fluid actuators have their cylinders linked together for synchronization.
No means other than the straight link, and no fine, adjustment of the individual actuators, are required for moving the blade means into leak-free contact with the fountain roller. Moreover, constantly held parallel to the fountain roller, the blade means is smoothly and quickly movable to open and close the ink outlet. It will also be apparent that the invention permits remote control of such operation of the ink fountain apparatus in association with the operation of the complete printing press with which the apparatus is to be incorporated.
The above and other objects, features and advantages of this invention and the manner of achieving them will become more apparent, and the invention itself will best be understood, from a study of the following description and attached claims, with reference had to the accompanying drawings showing a preferable embodiment of the invention.
REFERENCES:
patent: 1644723 (1927-10-01), Halliwell
patent: 3630146 (1971-12-01), Shields
patent: 3746957 (1973-07-01), Forster et al.
patent: 3877369 (1975-04-01), D'Amato et al.
patent: 4960052 (1990-10-01), Junghans
patent: 5533450 (1996-07-01), Hachiya et al.
patent: 5603262 (1997-02-01), Uera et al.
patent: 5709148 (1998-01-01), Uera et al.
patent: 5722324 (1998-03-01), Nishiwaki et al.
patent: 5842416 (1998-12-01), Olawsky et al.
patent: 9-226095 (1997-09-01), None
Hachiya Tadashi
Miyoshi Masahiko
Takahashi Yukitoshi
Arent Fox Kintner & Plotkin & Kahn, PLLC
Asher Kimberly
Kabushiki Kaisha Tokyo Kikai Seisakusho
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