DE2545627B2 - CONTROL DEVICE FOR THE CORRECT FEEDING OF CUT SIGNATURES TO A CYLINDER OF A FOLDER - Google Patents

Description

30th

The invention relates to a control device for the correct supply of cut signatures a cylinder of a folder, with means being arranged on the cylinder and on a stationary one Device are moved past, through their optical interaction a photocell exposure can be triggered and whereby via the photocell in the event of a faulty supply of a signature via a control circuit Machine functions are triggered.

This means that if a signature is incorrectly supplied, -to shut down the rotary printing press upstream of the folder and knock off the paper web before the resulting blockages can cause serious malfunctions and damage to the folder.

In a known embodiment of this type (DT-OS 16 11 278) is in one for dipping a wiper tongue serving annular groove of a jaw cylinder in one of the jaws downstream in the direction of rotation Cheek section arranged a reflective film, which when rotating the cylinder on a stationary Device is moved past, which carries a light source and a photocell. As long as the reflective tape of is covered by a folded product, the photocell is not influenced in any way; only if a body of If the reflective tape reflects a beam of light, a pulse is triggered with the consequences described above.

Another known version (DT-OS 23 39 902) contains for light guide cables in connection with a Photocell a front opening and a rear opening between the so Grippers of the cylinder, these openings being at a distance of a permissible tolerance. she allows therefore also only the detection of limit values at which the machine must be shut down.

The object of the invention is to improve such a control device so that the tendency of the Leading or trailing of the signature leading edge can be detected in order to be able to regulate and a Avoid shutting down the machine if possible, although of course also in extreme cases the Machine can be shut down.

This object is achieved by the identification specified in the claim.

The mode of operation is described with reference to the drawing which shows an exemplary embodiment. It shows

1 shows a plan view of a signature on a gripper pad with two grippers,

2 to 4 show a cylinder section with three different positions of the beginning of the signature relative to the reflection bar with adjacent recording of the impulses according to time and their time Chopping into a number of pulse fractions.

In Fig. 1 is denoted by 1 a cut sheet, which is grasped by two grippers 2 on a gripper system 3. With 4 a parallel reflection bar is indicated, which is located between the two grippers 2 of a transport cylinder 5 and has a length in Has the circumferential direction of the cylinder, which is within an allowable tolerance. Reflected over this length an output light beam 7 to each point while passing a stationary photocell device 6 a reflection beam 8.

In Fig. 2, with a direction of rotation of the transport cylinder 5 in the direction of arrow D, a large lag of the start of the signature compared to the co-rotating reflection bar 4 is assumed. This corresponds to a long pulse output a above the base line c after the time Z. In FIG. 3, a smaller lag of the start of the printed copy compared to the reflection bar 4, corresponding to the correct position, is assumed. This corresponds to a shorter impulse b above the base line c after the time ZIn F i g. 4, the beginning of the signature is in front of the reflection bar 4. There is no reflection at all, as well as no impulses above the baseline c. The chopping of the pulses a and b into pulse fractions a ' and b' recorded on the far right, which is carried out synchronously with the machine speed, shows the emergence of a number of pulse fractions, the number of which becomes an analogue for the length of the pulse when counting is carried out the time Zund is thus for the degree of lag or lead and, with ongoing monitoring, allows the tendency to be recognized in good time so that regulations can be made.

The number of pulse fractions that can be determined digitally or analogously is a measure of the instantaneous Status of the beginning of the signature. For this purpose, threshold values can be used to which a furthest lagging or am corresponds to the furthest leading print copy start when it is reached optical or acoustic signals are initiated or the machine is shut down.

For this purpose 2 sheets of drawings

Claims (1)

Claim: Control device for the correct feeding of cut signatures to a 7: '··' er of a folder, with means on the cylinder are arranged and are moved past a stationary device, through the optical interaction of which a photocell exposure can be triggered and with a control circuit triggering machine functions via the photocell if a signature is incorrectly supplied, characterized by the arrangement of a parallel reflection bar (4) or a parallel light beams emit a light source of a ^{length in the circumferential direction containing a '5} permissible tolerance on the cylinder (5) between its grippers (2) and the equipment of the control circuit with a chopper running synchronously with the machine speed for the received pulses of the photocell in fractions of that to pass the reflection bar or the light source required time and a comparison circuit in which these pulses are counted and the actual value is compared with a target value.