US2701420A - Device for checking the process results of printing presses - Google Patents

Description

Fil ed Nov. 20, 1952 Y J. F. MONROY EI'AL Feb. 8, 1955 DEVICE FOR CHECKING THE PROCESS RESULTS OF PRINTING PRESSES United States Patent f DEVICE-FOR CHECKING THE'PRDCESS RESULTS or rnmrmcrnnssns Johan Frederik Monroy, Amsterdam, and Willem Lenaarts', Haarlem Netherlands, a'ssignors to "hting Ins 'tuiit'yoor Grafische Techniek 'T. N. 0., Amsterdam, Netherlands,-acorporated liody Application November 20, 1952, Serial No. 321,702

Claims priority, application Netherlands November 24, 1951 Claims. (Cl. 33-1845) The invention relates to a device for checking the process results of printing presses.

It is known that a printing press is provided with a rotating cylinder with an elastic lining, on which cylinder the paper to be printed is placed, and with a printing plate making forward and backward movements, on which the printing form is mounted, which is appropriately provided with printing ink. The paper is printed by means of the combined movements of the cylinder and the printing plate.

In order to achieve the clean and unblurred printing and to prevent undue wear of type it is necessary at the point where the type is in contact with the paper sheet, the velocities of paper and of type should be exactly the same, i. e. that the distance covered by the paper is the same as the distance covered by the printing form. As a matter of course this is unrealizable in actual practice, but a discrepancy frequently amounts to 0.5 to 1.0 mm., sometimes even up to 3 mm. Such a discrepancy causes abrasion which is specially substantial at the beginning and at the end of the printing form. Consequently it is of the utmost importance to regulate the velocities of the printing form and the cylinder very accurately. This is a very time-consuming work, as it cannot be done at one go, the result being often unsatisfactory, as explained above. The cause of this is that, since the lining of the press cylinder is more or less elastic and in order to obtain a proper print a rather considerable pressure must be exerted upon it, the radius of the cylinder at the point of contact of the sheet of paper and the printing form is not accurately to be determined, so that it is impossible to ascertain straight away whether the velocity of the sheet of paper at the point of contact with the printing form indeed corresponds with that of the printing form, and, if it does not, how great the discrepancy is.

The present invention is intended to obviate this drawback and to enable the press to be regulated quickly and very precisely, by accurately measuring the possible discrepancy between the distance covered by the sheet of paper and that of the form, under conditions as prevailing during the printing proper. The device according to the invention mainly comprises instead of the printing form a holder to be mounted on the carriage, provided with a strip which can easily move over it.

The holder is provided with a device indicating a possible movement of the strip, such as for example a dial gauge. The device has a height exactly corresponding with the height of the printing form, so that when, on moving the carriage, it is pushed under the press cylinder provided with a sheet of paper, the circumstances prevailing during the printing proper, are imitated as accurately as possible. If, on printing, the velocity of the paper at the point of contact should not exactly correspond with that of the printing form, the strip will be slightly shifted in relation to its holder. The knowledge of this shift enables the mechanic to regulate the printing press quickly and with every degree of accuracy desired. The invention will be elucidated with the help of an embodiment as shown on the following drawings, of which Fig. 1 is partly a longitudinal section and partly a side aspect and Fig. 2 represents a cross section.

The device consists of a U-shaped holder 1C, provided with a strip 9, which, owing to a conveyor consisting The touching' piril-s of'tlie 'dialfgail'g'e ism coma ca'te's every mbvemerit'dt the strip in relation to'the holder; [The teps: are" fastened n ftheho1der by "means of dowels '7 and? screws ,11. .The strip isishii'flin'between pressure spri s 3" the ass st 'whieh'z est 'ag'airist' 'tlie .s'top'si The .sprang w ichiis connected with s p 1 does not rest on this directly, but on 'aiftidj'iistztbl' srW'Z. By screwing in this screw more or less, the neutral position of strip 9 in holder 10 can be adjusted in such a way that the dial gauge indicates 0. The extremities of cage 6 are provided with plates 4 which catch the middlemost windings of the respective springs 3. The effect of this is that the situation of the conveyor in relation to the strip and the holder is determined, so that the conveyor assumes the position as shown in Fig. 1, when it is not in operation. Without this provision it could happen that the cage moved in relation to the strip and the holder and that when in operationand consequently strip 9 is moved in relation to the holderit came into contact with one of the stops. Consequently, the conveyor, which is hampered in its movements by this contact, will exercise on the strip a friction power opposite to its movement, as a result of which it is possible that the strip does no longer follow the movement of the pressure cylinder entirely and the indication of dial gauge 14 becomes incorrect. The height of the whole device corresponds closely with the height of the printing form. In order to check the process results, the device is mounted on the printing plate temporarily replacing the printing form, with its length in the direction of movement of the printing plate.

The press is put into operation and the dial gauge is read to see whether the printing plate indeed is synchronized with the press cylinder or how great the discrepancy is. If the length of the controlling device is smaller than that of the sheet of paper to be printed, measuring may be done in several stages and the measuring results may be totalized.

It is also possible to use instead of the dial gauge or simultaneously with it a cathode ray oscillograph, by means of which irregularities in the speed of the printing press, especially at greater velocities, can be ascertained. In this case the strip should have a slight mass, which may be attained, for instance, by making it of an aluminum alloy.

We claim:

1. Device for checking the registry between the type form and the cylinder of a printing press comprising, a bed plate mountable in place of a type form on the type bed of the press, a follower slide slidably supported in said bed plate and having its upper surface protruding beyond said bed plate to contact said cylinder, and means to indicate a relative displacement of said slide with respect to the bed plate.

2. Device according to claim 1, wherein the follower slide is supported by a roller bed interposed between said slide and the bed plate and supported by the bed plate.

3. Device for checking the registry between the type form and the cylinder of a printing press, comprising, a bed plate mountable in place of a type form on the type bed of the press, a follower slide slidably supported in said bed plate and having its upper surface protruding beyond said bed plate to contact said cylinder, means to indicate a relative displacement of said slide with respect to the bed plate, studs mounted on said bed plate at the ends of said slide, and compression coil springs positioned with their axes parallel to the direction of the movement of said slide relative to the bed plate, one end of each spring abutting a respective end of said slide and the other end of each spring engaging a respective stud to maintain said slide floating between its extreme positions with respect to the bed plate.

4. Device according to claim 3 at least one of the studs being adjustable to vary the compression of the springs.

5. Device for checking the registry between the type form and the cylinder of a printing press, comprising, a bed plate mountable in place of a type form on the type bed of the press, a follower slide slidably supported in said bed plate and having its upper surface protruding beyond said bed plate to contact said cylinder, means to indicate a relative displacement of said slide with respect to the bed plate, studs mounted to said bed plate at the ends of said slide, and compression coil springs positioned with their axes parallel to the direction of the movement of said slide relative to the bed plate, one end of each spring abutting a respective end of said slide and the other end of each spring engaging a respective stud to maintain said slide floating between its extreme positions with respect to the bed plate, an anti-friction bearing interposed between said follower slide and said bed plate and comprising solids of revolution and a cage, said cage resting on said plate and provided with slots, said 4 solids being located in said slots, at least one end of said cage being provided with means to connect said cage to the middle-most winding of the adjacent spring.

References Cited in the file of this patent UNITED STATES PATENTS 359,402 Pafi Mar. 15, 1887 1,973,363 Wood Sept. 11, 1934 2,114,946 Trotter Apr. 19, 1938 2,372,428 Johnson Mar. 27, 1945 2,497,800 Root Feb. 14, 1950 2,593,713 Willett Apr. 22, 1952 2,636,278 Krause Apr. 28, 1953

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