Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F13/00—Common details of rotary presses or machines
  • B41F13/08—Cylinders
  • B41F13/20—Supports for bearings or supports for forme, offset, or impression cylinders
  • B41F13/21—Bearer rings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F33/00—Indicating, counting, warning, control or safety devices
  • B41F33/0072—Devices for measuring the pressure between cylinders or bearer rings
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/08—Measuring force or stress, in general by the use of counterbalancing forces
  • G01L1/083—Measuring force or stress, in general by the use of counterbalancing forces using hydraulic or pneumatic counterbalancing forces

Definitions

• the invention relates to a method and to a device for measuring the pretension between two bearers on rotary printing press cylinders that are in working contact with one another.
• the previously known methods for adjusting the bearer ring preload are in principle all based on a displacement measurement. Either the bearer deflection, the width of the contact zone of the Schmitzrihge or the compression of a stack of paper placed between the cylinders are measured. All of these methods are makeshift devices that measure a path that is not clearly dependent on them instead of the relevant force. Practical experience shows that this can cause difficulties.
• the invention has for its object to find a method and an apparatus for performing the method, whereby the direct measurement of the bearer ring preload is made possible.
• the printing unit cylinders are placed in the "Print from" position;
• Pressing the cylinders apart on the light gap between the bearer rings with a hydraulically generated force is an effective alternative to distance measurement.
• a force is directly measured here that clearly correlates with the preload force via the system rigidity.
• the narrow design of today's printing machines usually prevents this possibility. If the force, which would be possible in some cases, were applied between the cylinder journals, their rigidity will be changed so that a noticeable measurement error would be accepted. This measurement error does not apply if the force is applied to the cylinder barrel in the immediate vicinity of the bearer rings. This is As studies carried out showed, a highly precise and reproducible measurement is possible without damaging the cylinder surfaces by excessive surface pressure.
• Each cylinder with bearer rings has an undercut in the area of the pressure zone for the printing plate and blanket compared to the bearer ring. It is a minimum of 0.4 mm for the plate cylinder and a minimum of 2.0 mm for the rubber cylinder. This results in a gap of at least 2.4 mm when the bearer rings are on.
• the measuring device is introduced into this gap directly next to the bearer ring on the side selected for the measurement. Since the contact surface of the measuring device with the cylinders must nestle well, a separate measuring device is necessary for each print format, that is to say for different cylinder diameters.
• FIG. 1 shows a two-part device according to the invention, introduced into the gap between two printing unit cylinders, cut in the region of the printing medium supply;
• FIG. 2 shows an enlarged detail from the lower part of the device according to FIG. 3; 3 shows the lower part of the device cut in the region of a vent hole;
• Fig. 4 is a plan view of the lower part of the device according to FIGS. 3 and
• Fig. 5 greatly reduced a sketch of the location of the installation of the device.
• the device 1a consists of a lower part 1 and an upper part 2. These are inserted side by side into the gap 3 between the printing unit cylinders 4, 5 and then joined together so that the inner surfaces 6, 7 in contact with one another form a pressure chamber 8.
• the outer surfaces 9, 10 of the parts 1, 2 have the contour of the respective printing unit cylinder 4, 5.
• a closed groove 11 is provided, in which a sealing ring 12 is inserted.
• the outlet 13 of the inlet channel 14 is provided for the pressure medium.
• a further recess 15 extends concentrically to the sealing ring 12, into which a vent hole 16 opens.
• a membrane 17 covers the sealing ring 12 and recess 15 and is then glued to the lower part 1.
• the pressure chamber 8 thus forms between the bottom Part 1 and the membrane 17 supported by upper part 2. Oil flows into the pressure chamber 8 via the inlet channel 14, for example.
• the pressure p taken off via a pressure gauge connection 18 is therefore a clear measure of the force F hydr.
• a pressure gauge can therefore be calibrated directly in a force unit.
• the measurement for a special version with sealing ring and ventilation runs as follows:
• the adjustment mechanisms available for the bearer ring preload on the respective machine type are set so that a correct preload can be expected.
• the pressure chamber 8 enclosed by the sealing ring 12 is filled with oil through the inlet channel 14 when the pressure of the printing unit cylinders 4, 5 is switched off. Since the membrane 17 is pushed away, the air passes through the annular recess 15 lying outside the sealing ring 14 into the constantly open ventilation hole 16.
• the bearer rings 4a, 5a are now turned on, which seals the pressure chamber 8 to the outside. Now the oil pressure is increased with a hand pump until there is a light gap between the bearer rings 4a, 5a. Then the force F hydr. be read. After switching off the oil pressure, the bearer rings 4a, 5a are moved apart. If necessary, the preload setting is corrected and the measuring process repeated.
• the use of this device is so simple that it can be put in the hands of any operational mechanic.
• the part with the inlet channel 14 is expediently assigned to a rubber cylinder and the other to a plate cylinder. If you want to measure between rubber cylinders, the upper part 2 can be used with an intermediate layer. It is of course possible to use an upper part 2 adapted to the rubber cylinders instead of the intermediate layer.
• the preload setting increases significantly if an equal amount of force is applied to both bearer rings at the same time, since there are genuinely symmetrical conditions with respect to the cylinder center. It would therefore be very advantageous to work with two power transmitters connected in parallel to the same pressure source.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Inking, Control Or Cleaning Of Printing Machines (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6123001

Family Applications (2)

Family Applications After (1)

Country Status (3)

Families Citing this family (3)

Family Cites Families (8)

• 1981
  • 1981-01-21 DE DE19813101742 patent/DE3101742A1/de active Granted
• 1982
  • 1982-01-15 EP EP19820900344 patent/EP0070291A1/de not_active Withdrawn
  • 1982-01-15 WO PCT/DE1982/000011 patent/WO1982002515A1/de not_active Ceased
  • 1982-01-18 EP EP82100313A patent/EP0056643A1/de not_active Withdrawn

Non-Patent Citations (1)

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