US2404756A - Apparatus for correcting differences in register - Google Patents

Description

G. SPIESS July 23; 1946.

-APPARATUS FOR CORRECTING DIFFERENCES IN REGISTER 2 Sheets-Sheet l- Filed Jan. 8, 1942 In ven for 61M} M Af/brnigy G. SPIESS 2,

' APPARATUS FDR CORRECTING DIFFERENCES INREGISTER July 23, 1946.

Filed Jan. 8, 1942 2 Sheets-Sheet 2 In venlor "7 Flg Fig. 5

A. Alla/hey Patented July 23, 1946 APPARATUS FOR CORRECTING DIFFER- ENCES IN REGISTER Georg Spiess, Leipzig W. 31, Germany; vested in the Alien Property Custodian Application January 8, 1942, Serial No. 426,025

In Germany February 5, 1941 i 2Claims. (01.271-59) The invention relates to an apparatus for use on the feeding table of a printing machine for avoiding differences in register, which might ocour and result from the alteration of the paper by physical influences, such as moisture and temperature.

It is a well known phenomenon that, for instance when carrying out multicolor printing, the printing sheet expands after each impression owing to the moisture taken up from the printing ink, and consequently the several successive imprints do not fit accurately the one on the other, so that a perfect printing result can not be obtained. This same inconvenience occurs when the percentage of moisture contained in the air alters owing to change of temperature.

Apparatus for removing differences in register are known, which are provided on the delivery table of the sheet feeding table of the sheet feeder of the printing machine. It consists of a fanlike tongue, composed of two parts and adjustable relative to the surface of the table in vertical and lateral directions, said tongue adapted to be adjusted so that the side edges of the sheet lifted by it and resting on the surface of the table can be brought into the correct position relative to the lay marks for passing through. This fan-like tongue is mounted in the middle of the feeding table, co-ordinated to the lay marks, so that the sheet to be printed can be lifted only in the middle. If, however, the differences in register exist only, viewed in the conveying direction, on the left or only on the right hand side of the sheet to be printed, it is not possible to avoid these differences in register with the aid of this apparatus. The same is operative only if the differences in register are greater or smaller on the one side or on the'other side of the sheet to be printed than on the other side of the same.

:Such apparatus also involves the inconvenience, that the front edge of the tongue terminates at a greater distance from the lay marks, and consequently the sheet is pulled back towards the rear from the lay marks at the parallel lifting of the tongue. The fan-shaped arrangement is further prejudicial in that at the spreading of the two tongue-parts arranged one above the other, two different bearing planes are produced for the sheet, so that the sheet is lifted irregularly. Further, the tongue adapted to be adjusted in lateral direction can only be adjusted towards one side, with the result that only a unilateral lifting of the sheetcan take place. All these inconveniences are avoided according to the present invention in which no fan-shaped tongue is used.

According to the invention several small bars of sheet metal or the like are arranged on the feeding table of the printing machine in the conveying direction, one at a distance from and parallel to the other and adjustable in height and adapted to be lowered into the plane of the feeding table, and further adapted to be lifted individually parallel above the surface of the table as well as at an angle of inclination relative to the surface of the table, descending or ascending in the conveying direction according to require ment for avoiding the differences in register. The adiusting of the small bars cantake place during the service. if I A'n embodiment of the invention is illustrated by way of example in the accompanying drawings, in which Fig. 1 shows in side elevation the apparatus on a feeding table for laying on by hand,

Fig. 2 a cross section through the apparatus, at right angles to the conveying direction,

Fig. 3 a top plan view of the apparatus,

Figs. 4 and 5 are views, in front elevation and side elevation, respectively, of the adjusting device.

Figs. 6 to 10 show several adjustments by means of the apparatus.

In the embodiment illustrated, the apparatus according to the invention is provided on a feeding table for hand feeding of a printing press between the pile table I and the press 2 on the inclined feeding table 3. It is evident, that the apparatus may be used also in connection with a feeding table for automatic sheet feeding, in which the sheets are taken from a pile for instance b-y suction nozzles andfed by means of conveying bands onto the feeding table 3 of the.

press 2, the upper sides of these conveying bands moving in the plane of the table in grooves in the table,

The sheets are adjusted in known manner on the press 2 on lay marks 4, before they are taken over by the grippers of the printing cylinder.

According to the invention severa1 bars 5, 6, I are mounted at a distance from each other and parallel to each other on the feeding table 3 in the direction of conveying indicated by the arrow A, the surface of said bars being normally in the same plane as the surface of the table 3, these bars being located in indentations in the table 3, and mounted so that each bar by itself can be raised parallel to the plane of the table 3, as shown in Figs. 8 to 10, or adjusted at an angle 1 side and lesson the other side.

3 to the surface of the table, either descending in the conveying direction as shown in Fig. '7 or ascending in this direction as shown in Fig. 6. Each of the bars 5, 6, l which, for instance, are made of thin sheet metal, is fixed on a flat iron and this flat iron is fixed in turn on two U-shaped bearings 8 which are hingedly mounted on two rams 51 mounted below the feeding table. For each bar two rams 9 are provided, one ram in the front part and the other ram in the rear part of the bar. For each ram one adjusting device is provided. This adjusting device consists, as shown in Figs 4 and 5, for instance of an adjusting wheel l9, arranged on aside of the feeding table 3, the spindle H of this adjusting wheel having flat screw-threads engaging threads in aspindle wheel I2, and a control mechanism it, which is hingedly fixed on the one hand on the spindle wheel I 2 and on the other hand on a segmental bellcrank disc 14 which is mounted on the axle it so that it can freely move on the same and has a catch it which engages in a recess [-1 in the ram 9. Rotary adjustment of the adjusting wheel is therefore positively transmitted to the ram 9 which in turn adjusts the corresponding bar in a vertical direction. The ram 9 is guided between bearings IS.

The invention provides further, that by the lifting of the bars the sheet lifted thereby cannot bulge inward-1y behind the bars toward the front marks 4', as has heretofore been the case when the sheet was drawn away from the front marks. \Vith this object in view, an extension 6, I can be hingedly connected with the bars 5, 6, 1,

respectively, so that the point of the extension,

when any bar is lifted, remains in contact with the feeding table as shown on an enlarged scale in the upper part of Figure 1. the bar forms thereby a bridge for the lifted sheet, which consequently cannot bulge inwardly. The bridge may also be formed by providing a transverse bar which can be lowered into the feeding table and has an oblique surface, said transverse bar being adapted to be adjusted from below upwardly so that the inclination descends in forward direction.

The avoiding of the differences in register is effected by the apparatus according to the invention in the following manner:

If difierences in register have been ascertained on both sides of the sheet to be printed in transverse direction of said sheet, and these differences in register become perceivable, regularly or irregularly on both sides, these can be avoided by elevating the two bars 5 and I more or less uniformly or irregularly, whereby the sheet 19 to be printed, indicated in dash-dot-lines in Figure 3 of the drawings, is more or less reduced in widthat both sides uniformly or more on the one If only small differences in register occurred uniformly on both sides of the sheet it is sufficient, to raise only the middle bar; At differences in register occurring in the longitudinal direction of the sheet, i. e. in

The extension of the direction of conveying, the bars are adjusted accordingly obliquely, whereby the sheet is pulled back on the lay marks or pushed foreward, according to whether the bars have been inclined at an ascending or at a descending angle. If differences in register have been ascertained only on that side of the sheet which is at the right hand side in the conveying direction, these differences in register can be regulated either by uniform lifting of the bar 5 or by adjusting this bar at an angle. The bar 1 must be adjusted accordingly, if differences in register have to be corrected on the left hand side of the sheet. In thisinstance the'midclle bar 6 may also be used. The attendant can therefore use the bars according to requirement and is able to carry out all corrections necessary for overcoming differences in register merely by properly adjusting the bars.

After the adjusting of the bars, the sheet 19 to be printed is no longer. lying plane on the feedin table 3, but slight bulges are produced in the sheet to be printed, and the corners of the sheet to be printed are either pulled back or pushed forward on the gripper edge.

By the employment of th apparatus the operation of the lay marks is not altered in any manner or impaired. The bulges in the sheet to be printed are removed during the rolling of the printing cylinder by the counterpressure of the counterpressure cylinder produced at the transmission of the picture to be printed, this result being favored by the fact that the paper absorbs moisture during the rinting and thereby becomes less resistant and more yielding.

I claim:

i 1. A device on the feeding table of printing machines for removing differences of register resulting from the alteration of the'paper by physical influences such as moisture and temperature; comprising in combination with the feeding table, several bars of sheet metal arranged in the conveying direction in said feeding'table in parallelly spaced positions two rams for each bar arranged below said feeding table and hinged to the bar, each of said rams having a recess, shiftable means extendin into said recesses for moving the rams and adjusting the bars vertically.

2. A device on the feedin table of printing machines for removing differences of register'resulting from the alteration of the paper by physical influences such as moisture and temperature, comprising in combination with the feeding table, several bars of sheet metal arranged in the conveying direction in said feeding table and parallelly'spaced from each other at suitable distances, two rams for each of said bars arranged below said feeding table and hingedly connected toihe bars, each of said rams having a recess, shiftable means extending into said recesses for moving the rams and adjusting the bars vertically, and an extension hingedly mounted on each bar and serving as bridge for a sheet elevated on the bars.

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