Search

DE-102024132622-A1 - pollination device

DE102024132622A1DE 102024132622 A1DE102024132622 A1DE 102024132622A1DE-102024132622-A1

Abstract

A device for dusting sheets with powder in a printing press comprises powder nozzles (8) and support air nozzles (10, 11). Adjacent to each powder nozzle (8), two associated support air nozzles (10, 11) are arranged on connecting centers (14, 15), which connect a center point (M) of the respective powder nozzle (8) with centers (M) of two adjacent powder nozzles (8).

Inventors

  • Claudius Haas

Assignees

  • HEIDELBERGER DRUCKMASCHINEN AKTIENGESELLSCHAFT

Dates

Publication Date
20260513
Application Date
20241108

Claims (6)

  1. Device for dusting sheets (2) with powder (5) in a printing press, comprising powder nozzles (8) and support air nozzles (10, 11), characterized in that , in addition to the respective powder nozzle (8), two associated support air nozzles (10, 11) are arranged on connecting centers (14, 15) which connect a center point (M) of the respective powder nozzle (8) with centers (M) of two adjacent powder nozzles (8).
  2. Device according to Claim 1 , characterized in that the support air nozzles (10, 11) have elongated air outlet surfaces (A).
  3. Device according to Claim 2 , characterized in that the air outlet surfaces (A) are rectangular.
  4. Device according to Claim 2 , characterized in that the air outlet surfaces (A) are arc-shaped.
  5. Device according to Claim 1 or 2 , characterized in that the connecting centers (14, 15) together form a straight alignment line (16) on which the centers (M) of the powder nozzles (8) lie.
  6. Device according to Claim 1 or 2 , characterized in that a powder air jet (9) of the respective powder nozzle (8) and support air jets (12, 13) of the two associated support air nozzles (10, 11) penetrate each other before the powder air jet (9) and the support air jets (12, 13) hit the arc (2).

Description

The present invention relates to a device for dusting sheets with powder in a printing press, comprising powder nozzles and support air nozzles. Such devices serve to prevent the sheets from sticking together in the stack. For example, in DE 10 2008 049 547 B4 such a device was described. The object of the invention is to create a further pollination device. The problem is solved by a device for dusting sheets with powder in a printing press, comprising powder nozzles and support air nozzles, characterized in that, in addition to the respective powder nozzle, two of the support air nozzles are arranged on connecting centers which connect a center point of the respective powder nozzle with centers of adjacent powder nozzles. One advantage of the device according to the invention is that it ensures a streak-free application of powder. An additional advantage is that even powder distribution is achievable at all printing speeds. The following further training opportunities are available: The support air nozzles may have elongated air outlet openings. The air outlet openings can be rectangular. The air outlet openings can be curved. The connecting centers can together form a straight line on which the centers of the powder nozzles lie. A powder air jet from the respective powder nozzle and support air jets from the two associated support air nozzles can penetrate each other before the powder air jet and the support air jets hit the arc. Further information can also be obtained from the following description of an exemplary embodiment and the associated drawing. It shows: 1 A diagram of a printing press with a dusting device in side view, 2 a detailed representation of the pollination device in frontal view, 3 a detailed top view of the pollination device, 4 a modified embodiment of the pollination device. One in 1 The sheetfed offset printing press shown in the excerpt comprises a sheet delivery unit with a transport device 1 that carries freshly printed sheets 2 with ink and/or varnish (see 2 The sheets 2 are transported one after the other past a dusting device 3 to a delivery stack 4 and placed thereon. During this process, the sheets 2 are sprayed with powder 5 by the dusting device 3, which prevents the sheets 2 from sticking together in the delivery stack 4. The transport device 1 has gripper bridges attached to circulating conveyor chains, which grip the sheets 2 transported in the direction of transport 6, which for simplicity are shown in 1 Note those not shown. 1 Also not shown is a curved guide plate 7 (see 2 ), which guides the bow 2 during transport in the area of the pollination device 3. 2 Figure 6, viewed in the direction of transport 6, shows the dusting device 3, which has a series of evenly distributed nozzle groups. Each nozzle group includes a powder nozzle 8 that emits a powder air jet 9 consisting of blown air and added powder 5 (see Figure 5). 1 ). In addition, each nozzle group comprises two separate support air nozzles 10, 11, each of which emits a support air jet 12, 13 consisting of blown air without powder. The powder nozzle 8 is arranged between the two support air nozzles 10, 11 assigned to it. In 2 For the sake of simplicity, the powder air jet 9 and the support air jets 12, 13 are only symbolically indicated by arrows. In reality, however, the powder air jet 9 and the support air jets 12, 13 widen towards the arc 2 to be dusted. In 3 The pollination device 3 is in the direction of view III (see 2 ) shown. An imaginary connecting center 14, 15 extends between a center point M of the respective powder nozzle 8 and the centers M of the adjacent powder nozzles 8. The two support air nozzles 10, 11 of each nozzle group are arranged such that their nozzle opening surfaces or air outlet surfaces A are intersected by the connecting centers 14, 15. In the illustrated example, the connecting centers 14, 15 intersect the air outlet surfaces A of the support air nozzles 10, 11 exactly in the middle. However, it would also be possible for the connecting centers to The connecting centers 14, 15 intersect the air outlet surfaces of the support air nozzles 10, 11 off-center, with the centers of the air outlet surfaces A being slightly offset relative to the connecting centers 14, 15. The connecting centers 14, 15 of the powder nozzles 8 together form a straight alignment line 16, on which the powder nozzles 8 are arranged at a uniform center-to-center distance V from one another. The air outlet surfaces A are elongated and have a length S and a width B, where B < S. The powder nozzles 8 each have a circular nozzle opening area with a diameter D, where B < D and S < D. The size of the air outlet area A of the respective support air nozzle 10, 11 is smaller than the size of the nozzle opening area of the powder nozzle 8, where in the case of the 3 For the rectangular shape of the air outlet surfaces A shown, the following applies: S × B < ¼ π × D 2 The function is as follows: Each powder air jet