Ryobi Limited

Yoshinori Honkawa

Kenso Maehara

Koji Ishii

Takahiko Shinmoto

Nobuhiko Fujisawa

Masamichi Sasaki

Takashi Sakaguchi

Tomoyuki Tasaka

A LED radiates light on a plate held on plate cylinder upon receiving a radiation start signal, so as to form an irradiated area on plate. A photo diode (PD) senses substantially only conventional catoptric light reflected from irradiated area and generates the sensed signal representing the conventional catoptric light intensity. A data processing unit computes the dampening volume based on the sensed signal which is stored in storage device 9, storage device 9 then generates dampening volume signal. The LED is held in such manner that an incident angle of the light in connection with the surface of the irradiated area is made at predetermined angle sufficient for changing the conventional catoptric light intensity sensed by PD in accordance with the dampening volume.

System for determining dampening water for an offset press using

A printing machine is disclosed in which a sleeve having a tapered side surface is provided movably in an axial direction to a gripper shaft 5 arranged in parallel to a plate cylinder shaft 2. A sleeve member 25 is provided movably in the axial direction of the plate cylinder shaft 2. The sleeve member 25 is connected to the sleeve by a swingable arm. A screw 18 which is brought into contact with the tapered side surface of the sleeve is fixed to a bracket 16 mounted on the gripper shaft 5. Furthermore, a plate 13, a gripper 10 and a front abutment are provided on the gripper shaft 5, the front abutment being moved. An amount of displacement of an image position on the printing plate relative to a regular or normal position is obtained by intersecting two lines 47b and 47c formed at the clamp end portion. Since the method is related to a method of drawing two lines 47b and 47c having any width, it is possible to eliminate an error generated due to a configuration error of a register mark and it is possible to detect the image position width high precision. Accordingly, when the printing plate is automatically fed to the plate cylinder of an offset printing machine, it is possible to feed the printing plate with the image on the printing plate being parallel to the plate cylinder.

Offset printing machine, printing plate and image position reading-out

There is provided a sheet feeder for a sheet-fed press which allows an optimum separation state of printing sheets 27 to be established readily and certainly. Air is jetted out from an injection nozzle 6 toward the upper part of a bundle 2 of printing sheets to thereby float up printing sheets 27. A top printing sheet 27 thus floated is absorbed by an absorption foot 8 and conveyed to a printing process. The number of floating printing sheets 27 is detected using photoelectric sensors 21 and 22, and in order to establish the optimum separation state, is adjusted by varying the injection air quantity from the injection nozzle 6 or by moving the paper pressure bar 4 in directions of arrows 93 and 94. Further, by equalizing outputs G1 and G2 from detection areas M1 and M2, it is possible to place the top printing sheet 27 in parallel with the absorption surface 8Q of the absorption foot 8 and realize secure absorption. A fuzzy inference system may be used for adjustment.

Sheet feeder for sheet-fed press

A printing apparatus of the type capable of printing on both sides of a paper supplied thereto is improved by enabling simple operation through the use of a single operating lever. Adjustment devices allow simple vertical and transversely adjustment of the plate cylinders with respect to the paper position. After printing is effected, the operating lever is shifted stepwise from the printing position to a starting position through intermediate positions wherein blanket cleaning and plate ejection functions are effected. Changeover between single and two-sided printing is easily effected by a simple switch operation.

Offset perfecting press

An offset printing machine including an operating lever mechanism in which, before the printing process is started, all required preliminary processes can be carried out while the operator can visually confirm them to thereby prevent unsatisfactory printing operations due to erroneous plate insertion. The operating lever is rigidly coupled to an operating shaft upon which are mounted cams and arms for controlling each of a plate loading device, a plate unloading device, a blanket cylinder cleaning device, a form roller control mechanism, a plate cylinder control mechanism, a sheet feed control mechanism, a water duct roller control mechanism and an ink duct roller control mechanism in accordance with the angular position of the operating shaft. The plate loading device includes a switch structure having a memory circuit adapted to be set to open and closed positions in accordance with a plate loading operation and to store a plate loaded state even during a restoring operation which is carried out upon completion of the plate loading operation.

Operating lever device for printing machine

A device for preventing irregular supplying of printing sheets in a printing machine in which the supply of two or more printing sheets stuck together is positively prevented even if the quantity of light passing through a printing sheet is changed such as by a change in an original plate. A detection circuit detects the quantity of light passing through the printing sheets. The output of the detection circuit is coupled to a memory circuit which is activated to store a value representing a quantity of light corresponding to a single printing sheet. This operation is performed in advance before a printing operation is started. A control circuit operated by the memory circuit controls the printing machine operation such that the sheet supplying operation is suspended when the quantity of light detected by the detection circuit is less than the value stored in the memory circuit.

Device for preventing irregular supplying of printing sheets for

A transfer control roller having individually adjustable surface portions is provided between a fountain roller and a succeeding ductor roller. The surface portions can be moved radially inwardly and outwardly to vary the content surface between the fountain roller and respective surface portions, thereby varying the amount of transferred ink or water.

Automatic ink or water quantity adjusting device for printing machine

A number printing machine for use with an offset printing press in which, with only a single numbering device, both a present and a successive number printing operation in which a desired number is printed a desired number of times can be carried out. Either of the two printing modes of operation can be selected by one action. A counter is provided which counts the number of times of printing of a number up to a value set on a dial unit. Once the preset value has been reached, a solenoid is actuated in response to which the number to be printed is changed to the next succeeding number.

Number printing machine for offset press

Apparatus is disclosed for controlling the operation cycle of a duplicating machine. Each complete operation cycle of the duplicator includes plate loading, eching, inking, imaging, duplicating, blanket cleaning and plate removing processes. The number of revolutions of any cylinders constituting the duplicator and rotated synchronously with each other are counted by a counter. The counter starts and terminates its counting operation every time each of all the processes required for the duplicator is started and completed, in order to determine the period of time for carrying out each of the processes, thereby enabling always to maintain the best and uniform printing effect through a simpler and easier control than in a conventional duplicator.

Apparatus for controlling operation cycle of duplicating machine

A control mechanism for an offset printing machine in which total printing operation is efficiently and easily carried out through a single control shaft with a knob. The control mechanism is operative in a combination of an automatic mode and a manual mode to utilize advantages of both modes. The control shaft is rotatively constructed in such a way that its neutral position, its position for supply of ink and dampening solution to rollers, its position for transfer of ink and dampening solution to a master cylinder, its position for paper feeding and printing, its position for blanket cleaning, and its position for stopping the machine make one complete cyclic loop. The control shaft is manually rotated stepwise from its neutral position to its position for paper feeding and printing. After a pre-set number of sheets are printed, the control shaft is automatically rotated to its position for blanket cleaning and then to its position for stopping the machine.

Control mechanism for an offset printing machine

The printed sheet guide mechanism in an offset printing press comprises a stay provided parallel to a delivery roller which is in frictional contact with the eject rollers to rotate therewith, and a pair of guide members each of which has a slanted or curved guide flap. Each of the guide members is secured to the stay so that they are adjustable in their lateral movement, and is also so adapted as to hold at its both edges the printed sheet delivered out passing between the eject rollers and delivery rollers. The guide flap provided in each guide member is designed to bend or curve both edges of the printed sheet to give stiffness thereto.

Growing community of inventors

Fuchu, Japan

Yoshinori Honkawa