T 0152/98 12-06-2001

Main request of the appellant

1. Amendments

Claim 1 differs from claim 1 as granted substantially in the following features:

(a) the claim is restricted to a plate replacing apparatus for a printing press comprising a plurality of printing press units;

(b) a belt-driven drive shaft is provided which meshes with the plate cylinders through gears; and

(c) the controller is "adapted to sequentially operate said plate lockup opening/closing unit, said predetermined plate position stop unit, said plate holding apparatus drive unit, said plate removal unit, said plate supply unit and said plate press unit for said plurality of printing press units according to a predetermined timing in the order of the arrival of each plate cylinder at its plate removal position and in the order of the arrival of each plate cylinder at its plate supply position, respectively, with the movement of all plate cylinders being performed synchronously in a first and a second direction, respectively."

In the application as filed, the preferred illustrated embodiment incorporates feature (a), feature (b) is present in claim 2 as granted, the subject-matter of which was disclosed in the application as filed, and feature (c) is described with reference to Figures 16 to 21 at column 18, line 53 to column 26, line 38 of the published version of the application as filed.

Claim 2 differs from claim 3 as granted, the subject-matter of which was disclosed in the application as filed, only by virtue of clarifying linguistic amendments.

The amendments to the independent claims 1 and 2 thus comply with the requirements of Article 123(2) EPC. In addition, the amendments involve a restriction of the protection conferred and thus also comply with the requirements of Article 123(3) EPC.

2. Inventive step

2.1. Closest prior art

As accepted by both parties, the closest prior art is represented by document E3.

The disclosure of document E3 is largely concerned with automatic plate exchange in a single printing press unit. The procedure for removing an old plate and mounting a fresh plate is described at column 8, line 20 to column 10, line 4.

As disclosed in this passage, the procedure for removing an old plate and mounting a fresh plate is carried out by the sequential operation of five push buttons (54a) to (54e), as illustrated in Figure 3.

In order to remove a plate (16), a plate dismount preparation push button (54a) is depressed. This results in relaxation of the plate, followed by the trailing side lockup device (17b) being brought to a dismount position, whereafter the plate cylinder (10) stops. Thereafter, the trailing side lockup device is opened, these operations being carried out automatically. Then, the trailing side of the plate is gripped manually by the operator.

Next, a plate removal start button (54b) is depressed. The plate cylinder is rotated in the reverse direction, and when the leading side lock-up device (17a) has come to the dismount position, the plate cylinder stops. The plate is then removed. This plate removal operation is summarised in Figure 1A.

In order to start mounting of a plate, a plate mount preparation button (54c) is depressed. The plate cylinder rotates in the normal direction, and when the leading side lock-up device has reached a mount position (through the procedure shown in Figure 1C), the plate cylinder stops. The new plate is then inserted manually into the leading side lock-up device.

Next, the plate bite start push button (54d) is depressed in order to press the plate against the plate cylinder by means of a tightening roller.

Thereafter, a plate wrap start push button (54e) is depressed and the plate cylinder rotates in the normal direction, and the tightening roller advances to press the plate against the plate cylinder. The plate cylinder is then further rotated, and when the trailing side lock-up device has come to the plate mount position, the plate cylinder is stopped, whereafter mounting of the plate is completed.

The only disclosure in document E3 relating to the application of this procedure to a plate replacing procedure for a printing press comprising a plurality of printing press units is at column 10, lines 5 to 15, which reads as follows:

"While a method for exchanging a plate for one color stage has been described above, it is also possible to control in a similar manner the operation in which exchanges of plates are performed in parallel for a plurality of color stages. Also, while it is not shown in the illustrated embodiment, there are provided alarm means to operate when an abnormal condition has occurred during an automatic operation and display means for informing the location of the abnormal condition as well as a control circuit for these means."

It is thus necessary to construe the meaning of the reference in this passage to plate exchange being carried out "in parallel". It is suggested on behalf of the respondent that this refers to a procedure involving overlapping plate removal and supply.

However, such a procedure cannot be carried out using the mode of operation and the control system described in document E3 for a single colour stage. Thus, during removal of a plate, after the trailing side lockup device has been brought to the dismount position and has been opened, the trailing side of the plate is gripped manually by the operator.

The operator must then press the plate removal start button, whereupon the plate cylinder rotates in the reverse direction, and continues to rotate until the leading side lock-up device has reached the dismount position, whereupon the plate cylinder stops. During this time, the operator holds the plate in his hands. The plate is then removed.

During this procedure, all the plate cylinders rotate synchronously, since, in a conventional printing press, they are all connected by means of gears to a common longitudinal shaft.

In contrast, in order to carry out the method of claim 2 of the patent in suit, it is necessary to halt the rotation of all the plate cylinders at the point at which each of the remaining plate cylinders reach their respective plate removal positions. This is not compatible with the plate removal procedure described above.

A similar analysis applies to the procedure for mounting fresh plates.

After the leading side of a new plate is inserted manually into the leading side lock-up device, the plate bite start push button is depressed in order to press the plate against the plate cylinder by means of a tightening roller. Then, the plate wrap start push button is depressed and the plate cylinder rotates in the normal direction, and the tightening roller advances to press the plate against the plate cylinder. The plate cylinder is then further rotated, and when the trailing side lock-up device has come to the plate mount position, the plate cylinder is stopped, whereafter mounting of the plate is completed. Again, during this procedure, the operator holds the plate in his hands and it would not be feasible to halt the mounting operation of a plate each time one of the other plates reaches its mount position.

Further, Figure 2 of document E3 shows two colour stages of a printing press in which two plate cylinders are in phase. Whilst this would in principle enable plate exchange in each colour stage to be carried out simultaneously, this would require the simultaneous presence of operators required to remove and supply plates for each printing press unit. It is therefore more practical, also in the case of the plate cylinders being in phase, to remove and supply plates to the plate cylinders sequentially, that is, plate removal and supply for each plate cylinder only being initiated after plate removal or supply for a previous plate cylinder has been completed.

In the case of a printing press comprising a plurality of printing press units, the procedure disclosed in document E3 could thus be carried out according to either of the two methods described to in the patent in suit at column 2, lines 30 to 58 and referred to as the first and second methods. It thus appears that the reference at column 10, lines 8 and 9, of document E3 to exchanges of plates being "performed in parallel for a plurality of color stages" refers to plate exchange being carried out according to the second method. That is, plate removal operations for all the colour stages are carried out sequentially for each plate cylinder, whereafter plate supply operations for all the colour stages are carried out sequentially for each plate cylinder.

It is thus considered that document E3 does not contain a clear and unmistakable disclosure of a method in which, while synchronously rotating the plate cylinders in a first direction, each old plate is removed from each further corresponding plate cylinder as it has reached its respective plate removal position and has been stopped. Similarly, it is considered that document E3 does not contain a clear and unmistakable disclosure of an apparatus in which a controller is provided which is adapted to sequentially operate a plate lockup opening/closing unit, a predetermined plate position stop unit, a plate holding apparatus drive unit, a plate removal unit, a plate supply unit and a plate press unit for a plurality of printing press units according to a predetermined timing in the order of the arrival of each plate cylinder at its plate removal position and in the order of the arrival of each plate cylinder at its plate supply position, respectively, with the movement of all plate cylinders being performed synchronously in a first and a second direction, respectively.

2.2. Object of the invention

The object of the invention is to shorten the time required to carry out plate exchange.

As stated below, the object of the invention is not considered to be to enable fully automatic plate replacement. This could be achieved by use of a cassette as disclosed in document E1, but would not result in the method and apparatus as claimed in the patent in suit.

2.3. Solution

This object is achieved in a method of plate exchange as specified in claim 2, which results in overlapping of the plate removal and plate supply operations for the individual printing press units. Such a method is made possible in a printing press comprising plurality of printing press units by virtue of the provision of a controller as specified in the last sub-paragraph of claim 1.

This solution is not suggested by the cited prior art. Document E1 discloses a cassette which houses both old and new plates thus reducing the amount of handling of the plates during plate exchange. Such a cassette could be incorporated in the printing machine of document E3 in order to achieve this aim. The elimination of the necessity for the operator to manually handle the plates during plate exchange is a prerequisite for the method and apparatus of the patent in suit, in view of the number of personnel which would otherwise be required. This does not, however, imply that plate removal and plate supply operations are carried out in an overlapping manner, and there is no suggestion in document E1 that this should be done. The passage at page 6, lines 14 to 16 of the German translation of document E1 (E1c) merely states that the procedure described for a single printing unit should be repeated for each printing unit of a printing press having a plurality of printing units.

The subject-matter of claims 1 and 2 thus involves an inventive step. Claims 3 to 5 are directly or indirectly appendant to claim 2 and relate to preferred embodiments of the method according to the invention. The main request of the appellant is thus allowable and consideration of the auxiliary request is not necessary.