SU1377200A1 - Arrangement for transverse folding of sheets in folding apparatus for web-fed printing machine - Google Patents

Abstract

The invention relates to the printing industry and can be used for folding sheets: in the folding machine of web-fed printing machines. the device, the dimensions of the gears 6, 7 are chosen so that the working edge of the folding knife 8 moves along an elongated three-lobed hypocycloid, the intersection point of which lies on the surface of the folding cylinder 5, and the trajectory correction is carried out only on the exit section of the working edge of the folding knife for-: cases folding cylinder. The central gear wheel 6 of the planetary gearing makes an additional turn by means of the cam 1 attached to the folding cylinder. 4 il. i

Description

SL

Phie.1

The invention relates to a printing machinery industry, namely to the folding machines of the roll printing machines, and can be used in a cylinder group of a percussion-type folder for the transverse folding of tape cut off sealed sheets.

The aim of the invention is to increase the quality of folding and increase the reliability of the device.

Figure 1 shows a diagram of the proposed device; FIG. 2 shows a fragmentary trajectory of the working edge of a folding blade with a carrier: folding ratio of 2: 1 (hypocycloid); on fig.Z -; The trajectory of the working edge of the folding knife according to the calculated elongated hypocycloid in FIG. 4 is the same after the adjustment. The device includes (FIG. 1) the chopping cylinder I, the folding cylinder 2 with graphs 3 and the fal1} Zevalnye 4. The correction mechanism consists from cam 5, fixed on the folding cylinder 2, rocker arm 6 with roller 7 and connecting rod Sj pivotally connected to the central gear wheel 9, One end of the rocker arm 6 is pivotally connected to the bed, the second one - to the rod 8. In the proposed device, as in the folding apparatuses the gift type satellite gear ratio: 10 and the central wheel 9 is 1 g3. When the folding knife radius 11 is to the carrier, R.) j: its working edge moves along a three-lobe hypocycloid, a fragment of which is shown in FIG. 2 ( section of output of the folding knife beyond the limits of the folding cylinder),.

In the proposed device, the ratio Rj R is chosen such that the intersection point of the petals of the elongated hypocycloid lies on the surface of the folding cylinder (point dj in FIG. 3), i.e.

 RB,

R. Kfi + h

where R FC is the radius of the folding cylinder 2 (FIG. 1) | h is the distance from the folding cylinder-2 to the point of contact of the folding rollers 4 or the maximum output of the working edge of the folding knife beyond the folding cylinder (Fig. 3). Thus, to convert the curve shown in Fig. 3 to the straight line (Fig .4), the difference of the maximum and minimum radius vectors of the cam 5 (Fig.) Is insignificant and in relation to the newspaper folding apparatus is within 1.5 mm at a phase angle of 26.7 °,

The lengths of the carrier and folding knife are chosen in such a way that the point of intersection of the trajectories of the elongated hypocycloid lies on the surface of the folding cylinder, and cam 5 has two working profiles located through 180 °, each of which has one concavity and one bulge, and the phase angle of the section corresponds to the period of the working edge of the folding knife beyond the folding cylinder.

The device works as follows.

The front edge of the paper web 12 (Fig. I), after transversal cutting, is transported by grapads using a chopping cylinder 1. During transport, the folding knife 11 is pulled out from the body of the folding cylinder 2 and the paper sheet 13, which has been cut off and already released by the scribes 3, is pushed between the folding rollers 9.

The movement of the working edge of the folding knife in the folding section along a straight line eliminates its sliding relative to the sheet. This eliminates the knife's smearing of the freshly printed impression and allows for accurate transverse folding of the sheets. To this end, along the edge of the folding knife, you can install needles, which pierce the sheet along the line of the future fold, to prevent its displacement under the action of inertial, aerodynamic and other efforts.

Claims (1)

Invention Formula A device for transverse folding of sheets in a folding machine of a roll printing machine, comprising a cylinder, folding rollers and a folding cylinder having a gear planetary gear, the central gear wheel of which is mounted coaxially with the folding cylinder, a parasitic wheel and a satellite with a folding knife fixed on the carrier and a corrective mechanism associated with the bed, which includes a cam. steam, characterized in that, in order to improve the quality of folding and reliability of work, corrective fur ism comprises pivotally connected to the frame beam, interacts with a cam roller pair and is pivotally mounted on a central gear wheel rod, .sv coupled with a yoke, wherein the ratio of the lengths of the guide and folding blade is Si si 1 + R FC R where - the radius of the folding cylinder; carrier length; folding knife length; distance from the folding cylinder to the point of contact of the folding rollers. Kb RM - h Fie.2 Fig.Z FIG, if