Back to results
US 4,858,528 AGranted
Printing press and control method of plate feeding operation
AssigneeToray Industries, Inc.
InventorsYoshinori Inouye, Yoshihiko Osawa, Minoru Ueda
Life of this patent
Estimating the term…
Abstract
A printing plate (50) is provided with a plurality of positioning holes (50d) at the head portion (50a) on the basis of at least two cross sides (51a, 51b) of the printing plate (50). The printing plate (50) is delivered towards the plate cylinder (3) by the predetermined distance on the basis of two cross sides (51a, 51b) in relation to the rotation of the plate cylinder (3) so that each positioning holes (50d) can be engaged with the corresponding positioning pins (315) of the plate cylinder (3). This allows the printing plate (50) to be automatically and accurately mounted onto the designated position of the plate cylinder (3).
Claims13
A printing press for automatically feeding a printing plate having a lead edge portion provided with a plurality of register holes, and at least two sides extending from the lead edge portion, comprising:
- a printing press body;
- a plate cylinder mounted to said printing press body:
- a plurality of register pins provided at said plate cylinder and adapted to engage said register holes;
- a first driving motor for driving said plate cylinder;
- a plate feeding unit installed in said printing press body;
- a plate feeding tray having a positioning part means for guiding to set said at least two sides of the printing plate on a predetermined position of the plate feeding tray, said plate feeding tray being installed in said plate feeding unit;
- a plate forwarding mechanism including at least one plate-feeding driving roller provided at said plate feeding unit to advance the printing plate positioned on said plate feeding unit;
- a second driving motor for driving said plate-feeding driving roller;
- means for imparting a driving command signal to said first driving motor;
- means for generating a plate-feeding command signal;
- means for outputting a rotation phase detecting signal in relation to a rotation phase of said plate cylinder;
- means for imparting a plate-feeding start-up command signal for driving said plate-feeding driving roller with said second driving motor in response to said plate-feeding command signal when a rotation phase of said plate cylinder detected by said rotation phase detecting signal reaches a predetermined rotation phase;
- and
- means for controlling a rotating speed of said plate-feeding driving roller on the basis of said rotation phase detecting signal so that said register pins engage with said register holes after commencement of plate-feeding by said plate-feeding driving roller.
11 more elements
A method of controlling a plate-feeding operation in a printing press having a printing press body;
- a plate cylinder provided on said printing press body;
- a plurality of register pins provided on said plate cylinder;
- a first driving motor for driving said plate cylinder;
- a plate-feeding unit installed in said printing press body;
- a plate feeding tray installed in said plate-feeding unit and having a positioning part for guiding to set at least two sides of a printing plate on a prescribed position of the plate feeding tray;
- a plate-feeding driving roller provided at said plate-feeding unit to advance the printing plate positioned on said plate feeding unit;
- a second driving motor for driving said plate-feeding driving roller;
- means for imparting a driving command signal to said first driving motor;
- means for generating a plate-feeding command signal;
- and means for outputting a rotation phase detecting signal in relation to a rotation phase of said plate cylinder;
- said method comprising the steps of:
- positioning the printing plate provided with a plurality of register holes at a lead edge portion thereof into the plate-feeding unit;
- generating a plate-feeding command signal;
- providing a plate-feeding start-up command signal for driving said plate-feeding driving roller with said second driving motor in response to said plate-feeding command signal when a rotation phase of said plate cylinder detected by said rotation phase detecting signal reaches a predetermined rotation phase;
- and
- controlling a rotating speed of said plate-feeding driving roller on the basis of said rotation phase detecting signal so that said register pins engage with said register holes after start of plate-feeding by said plate-feeding driving roller.
13 more elements
A method of plate feeding operation of a printing press in accordance with claim 18, further comprising:
- an acceleration step that activates the plate-feeding operation at the predetermined rotation position of said plate cylinder after opening a plate-head holding member set to said plate cylinder before eventually leading said lead edge portion into a plate-insertion space between said plate-head holding member and said plate cylinder by raising the plate-feeding speed of the plate-feeding driving roller to a predetermined level faster than the circumferential speed of said plate cylinder;
- a deceleration step that decelerates the plate-feeding speed to a level almost corresponding to the circumferential speed of said plate cylinder after completing said acceleration step so that said lead edge portion can be led to the predetermined position in the farthest position of said plate-insertion space;
- a constant speed step that keeps the plate-feeding speed at a specific level almost equal to the circumferential speed of said plate cylinder until said plate-head holding member fully closes itself after completing said deceleration step;
- and
- a stop step that stops the plate-feeding operation after completing said constant-speed step.
2 more elements
A method of plate feeding operation of a printing press in accordance with claim 18, further comprising:
- a first step which, in response to a plate feeding/discharging command signal, releases a plate-head holding operation accomplished by a plate-head holding means at a first rotational position of said plate cylinder with respect to a first printing plate wound onto said plate cylinder;
- a second step which, after completing said first step, allows said plate-head holding means to lock the lead edge portion of a second printing plate at a second rotation position of said plate cylinder while drawing out said first plate from said plate cylinder using plate extraction means and simultaneously feeding said second printing plate to said plate cylinder using plate-forward means;
- a third step which, after completing said second step, unlocks a tail edge portion of said first printing plate from the state locked by said plate-holding means at a third rotation position of said plate cylinder and causes said first plate to be drawn out of said plate cylinder using said plate extraction means;
- and
- a fourth step which, after completing said third step, causes a tail edge portion of said second printing plate wound onto said plate cylinder to be locked by plate-end holding means.
2 more elements
Dependencies are inferred from the claim text.