Printing – Rolling contact machines – Rotary
Reexamination Certificate
1999-08-30
2001-10-30
Asher, Kimberly L. (Department: 2854)
Printing
Rolling contact machines
Rotary
C101S479000, C101S481000
Reexamination Certificate
active
06308622
ABSTRACT:
FIELD OF THE INVENTION
The invention concerns a device for use in a rotary printing machine.
BACKGROUND OF THE INVENTION
A typical form of rotary printing machine has at least one printing mechanism including a plate cylinder which can be releasably mounted to a shaft carrying it. The plate cylinder carries a printing plate which is fixedly connected thereto. If the printing plate is provided with the respective print image to be produced, in a special imaging or image-applying apparatus, that is to say outside the printing mechanism itself, it is then necessary for the printing or blanket cylinder, upon being fitted into the printing mechanism, to be properly oriented with respect to the shaft which carries it, in such a way that the print image which is transferred from the printing plate on to the printing cylinder is correctly oriented with respect to the article to which the printing is to be applied and on to which therefore the printing or blanket cylinder transfers the print image. In view of the fact that in many cases the number of articles to which printing is to be applied in the same fashion, that is to say the number of articles constituting a respective batch, may be very low, there is a need for the printing plate to be changed at short intervals of time. If the printing plate is fixedly connected to the plate cylinder, frequent changes in the printing plate entail correspondingly frequent changes in the plate cylinder. The amount of time that this involves is particularly significant when, as is normally always the case in offset printing, the article is to be successively provided with a plurality of partial print images each consisting of different colors or inks, which supplement each other to form an overall print image. This therefore requires a corresponding number of printing mechanisms and accordingly also plate cylinders, in the rotary printing machine.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a rotary printing machine which permits plate cylinder changes to be implemented in a simple fashion involving a minimum amount of time.
Another object of the present invention is to provide a rotary printing machine affording a structure such as to permit accurate adjustment of the respective plate cylinder so as to satisfy the nowadays usual demands in terms of print image quality.
Still a further object of the present invention is to provide a rotary printing machine affording adjustability of plate cylinder and print image such as to satisfy the particularly high demands in terms of accuracy of adjustment which are involved when an article to be provided with printing thereon is to be successively provided with a plurality of partial print images which must be accurately positioned relative to each other.
In accordance with the principals of the present invention the foregoing and other objects are obtained by a rotary printing machine having at least one printing mechanism which includes a plate cylinder which can be releasably mounted on a shaft carrying it. The plate cylinder and the shaft are adapted to as to enable orientation of the plate cylinder relative to its shaft both axially and also in a peripheral direction, and for fixing the plate cylinder to a shaft in an oriented position with respect thereto. The plate cylinder includes a means of positioning which comprises a first and second projection. Associated with the shaft is an adjustment means for adjusting the position of the positioning means enabling the plate cylinder to be positioned as desired. The adjustment means comprises a first and second adjustable bolt. The first projection is co-operable with the first adjustable bolt which is operatively associated with the shaft for fixing the position of the plate cylinder in the peripheral direction. The second projection is co-operable with the second adjustable bolt which is operatively associated with the shaft to fix the axial position of the plate cylinder relative to the shaft. The first and second adjustable bolts include a region against which the respective positioning means come to bear so as to enable convenient and accurate positioning of the plate cylinder in either the peripheral direction or the axial direction.
In accordance with a preferred feature of the invention, operatively associated with the plate cylinder is a collar which is also arranged on the drive shaft thereof and which is provided with the adjustable bolts, while the-first and second projections located on the plate cylinder are introduced into openings in the collar that are brought into contact in the openings with the adjustable bolts which determine the position of the plate cylinder both axially and also in the peripheral direction.
In accordance with a further preferred feature of the invention the use of conically tapering portions of said bolts which are adjustable in the direction of the longitudinal axis thereof affords the advantage that the operating position of the plate cylinder can be very accurately adjusted relative to the shaft by simple axial displacement of the conically tapering portion.
An operating procedure which has been found to be particularly advantageous is one in which the imaging apparatus is also so designed that the positioning of the plate cylinder in the imaging apparatus is in conformity with the positioning thereof in the printing mechanism so that it is only necessary for the imaged plate cylinder to be removed from the imaging apparatus and fitted on to the drive shaft in the printing mechanism, whereupon, using the arrangement according to the invention, orientation thereof can be effected therein, relative to the shaft, without each change in plate cylinder necessitating displacement of the conically tapering portions for the purposes of adjusting the position of the plate cylinder in the axial direction and in the peripheral direction. On the other hand however the invention also permits fast and in particular accurate adjustment of the plate cylinder in a simple fashion in the situations in which the conically tapering portions for determining the position of the plate cylinder on the shaft have to be set for the first time or re-adjusted so that a fast change of the plate cylinders including accurate adjustment thereof is possible even when the position of the plate cylinder in the imaging apparatus is not defined in relation to the position of the plate cylinder in the printing mechanism.
It will be appreciated that it is assumed in all cases that the position of the plate which is respectively carried by the plate cylinder is accurately fixed and defined in relation to the plate cylinder.
Further objects, features and advantages of the invention will be apparent from the following description of a preferred embodiment of the invention.
REFERENCES:
patent: 1328842 (1920-01-01), Marquardt
patent: 3143962 (1964-08-01), Dobson et al.
patent: 3724367 (1973-04-01), Pasinski
patent: 3750568 (1973-08-01), Weisgerber
patent: 4512256 (1985-04-01), Schriber et al.
patent: 5255604 (1993-10-01), Durr
patent: 2365201 (1975-06-01), None
patent: 9113505 (1992-02-01), None
Steffen Volker
Voigt Michael
Asher Kimberly L.
Drinker Biddle & Reath LLP
Werner Kammann Maschinenfabrik GmbH
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