EP0809574B1 - Powder-dusting arrangement - Google Patents

Description

a) einer Vielzahl von Düsen, über welche eine Puder-Tragluft-Mischung gegen die von Greifeinrichtungen des Transportsystemes der Druckmaschine vorbeibewegten Druckereierzeugnissen gerichtet wird;

b) einer Mischeinrichtung, in welcher der Puder mit Luft zur Erzeugung der Puder-Tragluft-Mischung vermischt wird;

c) mindestens einer Verbindungsleitung, welche die Mischeinrichtung mit den Düsen verbindet.

The invention relates to a powder dusting device for a printing press

a) a plurality of nozzles via which a powder-air mixture is directed against the printed products moved past by gripping devices of the transport system of the printing press;

b) a mixing device in which the powder is mixed with air to produce the powder-air mixture;

c) at least one connecting line which connects the mixing device to the nozzles.

Such a device is known from EP-A-375 799.

Powder dusting devices of this type are used to Printed matter in printing machines by the printing unit come and have gone through a drying section, to be provided with a powder layer, which in the following Stacking the printed matter stuck together prevented. For this purpose, they are close to the Transport level of the printed products arranged so that their nozzles mix the printed matter from air (air) and powder. in the general are the transport systems of printing presses formed by parallel endless conveyor chains through a large number of gripping devices connected to one another are. The gripping devices comprise a gripping mechanism, who hold the printed matter on the edge can, and protrude above the transport level of the printed egg certificates out. Therefore, in the known powder pollination facilities the nozzles are proportionate have a large distance from the transport level at which the gripping devices can pass. This large distance has the disadvantage, however, that the powder-air mixture, which is thrown out of the nozzles spreads in an uncontrolled manner in the printing press.

The object of the present invention is a powder dusting device of the type mentioned above To design that the powder-air mixture spatially more concentrated on the printed products can be.

d) eine Hubeinrichtung, welche die Düsen zwischen zwei Positionen hin- und herbewegen kann, nämlich

da) einer von der Transportebene der Druckereierzeugnisse verhältnismäßig weit entfernten ersten Position
und

db) einer verhältnismäßig nahe an der Transportebene der Druckererzeugnisse liegenden zweiten Position,

und

e) eine die Position der Greifeinrichtungen erfassende Steuereinrichtung, die mit der Hubeinrichtung derart zusammenwirkt, daß diese die Düsen in die erste Position bringt, solange sich eine Greifeinrichtung in der Nähe der Düsen befindet, und die Düsen in die zweite Position bringt, wenn die Greifeinrichtung sich in ausreichendem Abstand von den Düsen befindet.

According to the invention, this object is achieved by

d) a lifting device which can move the nozzles back and forth between two positions, namely

da) a first position which is relatively far away from the transport plane of the printed products
and

db) a second position which is relatively close to the transport level of the printed products,

and

e) a control device which detects the position of the gripping devices and which cooperates with the lifting device in such a way that it brings the nozzles into the first position as long as there is a gripping device near the nozzles and brings the nozzles into the second position when the gripping device is at a sufficient distance from the nozzles.

According to the invention, the nozzles of the powder dusting device no longer fixed. Much more you get a mobility perpendicular to the transport plane of printed matter, such that they are Approaching gripping devices can "dodge" in the relatively short period in which the Gripping devices pass under the nozzles, one keep a correspondingly large distance from the transport level. However, as soon as the gripping device passes the nozzles has returned to a position in which it the transport level and thus the one to be pollinated Surfaces of printed matter are very close. The close proximity of the nozzle openings to the print products allows a more controlled pollination than this known powder dusting equipment was possible.

a) mindestens ein mit einer Förderkette des Transportsystems zusammenwirkendes Kettenrad;

b) mindestens eine von dem Kettenrad getragene, in sich geschlossene Nockenfläche;

c) mindestens ein mit den Düsen verbundenes Nockenfolgeglied, welches mit der Nockenfläche zusammenwirkt;

d) eine Führungseinrichtung, welche die Düse auf dem Weg zwischen ihren beiden Positionen führt.

The lifting device, like the control device, can be implemented in very different ways. In a first exemplary embodiment of the invention, both the lifting and control device are constructed mechanically and combined with one another. It is characterized in that the lifting device and the control device are combined in a cam mechanism which comprises:

a) at least one sprocket interacting with a conveyor chain of the transport system;

b) at least one self-contained cam surface carried by the sprocket;

c) at least one cam follower connected to the nozzles, which cooperates with the cam surface;

d) a guide device which guides the nozzle on the way between its two positions.

In this embodiment, the detection of the Relative position between the gripping devices on the Transport system and the nozzles mechanically; the lifting mechanism does not require a special drive and the control device no own power supply. This embodiment is particularly robust and insensitive to faults.

It is preferred that two parallel cam surfaces are provided, which form a cam track in which the cam follower is included. The two in parallel Cam surfaces guide the cam follower in both possible directions of movement, so that the latter without Using additional components to perform its function can.

Quite conceivable and constructively a little easier but also an embodiment in which only one cam surface is provided and the cam follower by Biasing device pressed against the one cam surface is. In this embodiment of the invention So the movement of the nozzles in one direction below the influence of the cam surface which the nozzles counter pushes back the action of the pretensioner while the movement in the other direction from the pretensioner is effected, which is the cam follower of the Nozzles in contact with the (receding) cam surface holds.

In principle, however, it is possible and in many cases also easier to implement that the lifting device is mechanically separated from the control device. Latter can then be easily electrical / electronic To run. You can do this at the transport level arranged to include the first sensor when approaching a gripping device to the nozzles a first signal to the lifting device, which the lifting device causes the nozzle to move to the first position. The sensor can be any device which indicates the physical proximity of the gripping device responds, e.g. B. all forms of proximity switches, Light barriers, but also around mechanical switches, the actuator of the passing gripping devices is acted upon.

The "reset" of the nozzles in that of the transport level The near (second) position can in turn be different Ways are done:

So it is z. B. possible that the control device comprises a second sensor arranged on the transport plane, the second when a gripping device moves away Output signal to the lifting device, which the lifting device causes the nozzle to move to the second position.

An alternative to this is an embodiment of the invention possible, in which the control device a timer contains which of the first signal of the first sensor is initiated and after a certain period of time emits a second signal, which the lifting device Is fed and causes the nozzles in to bring the second position. This variant is likely generally cheaper than the one mentioned above, be control device working with two sensors. The time period defined by the timer between The occurrence of the first and second signals becomes like this chosen that at the respective speed of the Transport system is sufficient, the gripping device to the To let nozzles pass.

Depending on the constructional circumstances of the individual case can be one of the two following variants, to combine the nozzles into a nozzle assembly as prove particularly favorable:

The first variant is characterized in that the Nozzles are rigidly connected to a manifold and with this forms a movable unit that over a flexible hose connected to the mixing channel is. This variant comes with a single flexible Hose out, both in terms of material usage as well as in terms of assembly costs is. However, one that is rigidly connected to the nozzle means Manifold in general also a little bigger moving mass.

The point of view is the size of the moving mass in the foreground, an embodiment of the invention be selected in which the nozzles have a slight Support rod are connected to a movable unit and each nozzle over a flexible hose with one fixed manifold is connected, which in turn communicates with the mixing device. In this embodiment, the manifold not moving; the cohesion of the nozzle assembly, which combines the various nozzles, takes place over the support rod which is much lighter than one Distribution pipe can be. However, in this case a connection between each nozzle and the manifold be made using a flexible hose.

An embodiment of the invention is particularly preferred, which has a sensor that the position of the Nozzles are detected and an output signal is generated, which the mixer only works for as long as how the nozzles in the second position (close to the transport level). Pollination is so interrupted as long as the nozzles for passing one Gripping device are raised to the first position; in this way, the Above mentioned disadvantages avoided, which are known Find powder pollination facilities.

The lifting device is particularly easy to control, when they swing between the nozzles the two positions.

Constructively, this can advantageously be achieved that the lifting device has a single or multi-armed lever which carries the nozzles in a first position and in a second point is driven by a cam surface.

The movement between the nozzles is advantageously between the cam surface serving the two positions is so formed and driven that one revolution of the cam surface of the Movement of the transport system of the printing press around the distance between two successive gripping devices corresponds.

This synchronization of the cam surface movement on the movement of the printed matter can be particularly realize simply that the scope of a Cam surface driving sprocket equal to the distance successive gripping devices of the transport system is chosen.

Figur 1:

schematisch den Auslaufbereich einer Druckmaschine;

Figur 2:

ebenfalls schematisch eine in der Druckmaschine von Figur 1 vorgesehene Puderbestäubungseinrichtung in einer ersten Position der Düsen;

Figur 3:

eine Ansicht entsprechend der Figur 2, in der sich jedoch die Düsen in einer zweiten Position befinden;

Figur 4:

die Ansicht eines eine Nockenspur tragenden Kettenrades, welches bei der Puderbestäubungseinrichtung der Figuren 2 und 3 Verwendung findet; und

Figur 5:

eine schematische Darstellung eines abgewandelten Antriebes zum Verstellen der Düsen einer Puderbestäubungseinrichtung.

Embodiments of the invention are explained in more detail below with reference to the drawing; show it

Figure 1:

schematically the outlet area of a printing press;

Figure 2:

likewise schematically a powder dusting device provided in the printing machine of FIG. 1 in a first position of the nozzles;

Figure 3:

a view corresponding to Figure 2, but in which the nozzles are in a second position;

Figure 4:

the view of a cam track carrying sprocket, which is used in the powdering device of Figures 2 and 3; and

Figure 5:

a schematic representation of a modified drive for adjusting the nozzles of a powder dusting device.

In Figure 1 is the outlet area of a printing press shown. To the right of the area shown to think the actual printing unit. The printed matter are using the entire printing press With the help of a conveyor system that moves two endless Conveyor chains 1 includes. The visible in Figure 1 Conveyor chain 1 lies behind the drawing level; a corresponding is endless conveyor chain 1, parallel to that shown Conveyor chain 1 running, in front of the drawing level of Figure 1 attached. The two conveyor chains 1 are through a large number of gripping devices 2 with one another connected, which is perpendicular to the plane of the figure 1 extend and on each of which a gripping mechanism is attached for capturing a printed product. The Construction of such gripping devices 2 is on and for known.

The gripping devices 2 are along the conveyor chains 1 arranged at regular intervals from each other and transport the printed products from the not shown Infeed area of the printing press through the also not shown printing unit through and then in the sense of arrow 3 on one in Figure 1 only schematically indicated powder dusting device 4 over to one Stack 5 on which they are dropped.

Between the printing unit and the powdering device 4 there is generally a drying section, on which the still pressurized printed products largely dried, for example in the area of the conveying path provided with the reference symbol 6 '. Since the printed matter on the drying line, their length is limited for economic reasons must be kept, not completely dried be that mutual sticking excluded the powdering device 4 is provided, with which a powder layer on the printed products is applied. This prevents sticking together in stack 5 of the superimposed printed matter.

An embodiment of such a powder dusting device 4 is larger in Figures 2 and 3 shown to scale. A plurality of nozzles 6 that over a common manifold 7 are fed on the transport level of the conveyed by the conveyor chains 1 Printed products. The manifold 7 is via a flexible hose 16 with a Mixing device 8 connected, in which the powder, in generally a corn starch product mixed with air and so is conveyed to the nozzles 6.

A sprocket 9 is in the machine housing, which is not is shown in more detail by means of an axle stub 10 rotatably mounted and engages in the transport chain 1 one behind the plane of the drawing in Figures 2 and 3 is moved in the direction of arrow 3.

The circumference of the sprocket 9 corresponds to the distance below which the gripping devices 2 of the conveyor chains 1 are worn.

As can be seen in particular from FIG. 4, in the sprocket 9 on the manifold 7 facing Side formed a cam track 11, which are parallel to each other has extending cam surfaces 11a, 11b. The cam track 11 has the following shape:

Over a relatively small angle α, the cam track 11 follows an arc that is concentric with the center of rotation of the chain wheel 9 and has a relatively small radius. The angle range α is adjoined on both sides by angles β ₁ and β ₂ transition areas in which the cam track 11 changes from the smaller radius to a larger radius. In the remaining angular range, the cam track 11 follows an arc that is also concentric with the center of rotation of the chain wheel 9, but has a larger radius.

The distributor pipe 7 is with a cam follower Serving pin 12 projecting in the axial direction provided which engages in the cam track 11. The Distribution pipe 7 and thus the nozzles 6 are between two Guides 13, indicated by dashed lines in the drawing are movable in the vertical direction. The order is so that the vertical position of the nozzles 6 through the cam track 11, ultimately through the rotational position the sprocket 9 is determined.

The distance between two successive gripping devices 2 on the transport chain 1 corresponds to the scope of the Sprocket 9 or an integer multiple thereof. The sprocket 9 is mounted so that the cam track 11th in the angular range α, in which they are smaller than the circular arc Diameter follows, in engagement with the cam follower 12th of the distributor pipe 7, when under the nozzles 6 a gripping device 2 passes by.

The powdering device 4 described above works as follows:

As long as there is no gripping device in the vicinity of the nozzles 6 2, as shown in FIG. 3, is the cam follower 12 on the manifold 7 in the area of the cam track 11 which is the larger Has radius. This means that the manifold 7 with the nozzles 6 attached to it lowered far between the guides 13 is. The openings of the nozzles 6 face the towed ones Printed products, which are characterized by the Move conveyor chains 1 defined transport level, in relatively short distance from. This means, the powder-air mixture, which emerges from the nozzles 6 leaves, has relatively little opportunity to escape laterally.

Shortly before the next following gripping device 2 approaches the nozzles 6, the transition region of the cam track 11b leading in the direction of rotation (arrow 14) of the chain wheel 9, which corresponds to the angle β ₁ (FIG. 4), engages with the cam follower 12 so that the distributor pipe 7 with the nozzles 6 is raised by the angle β ₁ during the rotation of the chain wheel 9. The distributor pipe 7 and nozzles 6 remain in this raised position, which is shown in FIG. 2, during the period of time within which the chain wheel 9 passes through the angle α. Within this time, the gripping device 2 moves under the nozzles 6, for which there is sufficient space due to the relatively large distance between the nozzles 6 and the transport plane defined by the conveyor chains 1. After passing through the gripping device 2, the cam follower 12 of the distributor tube 7 gets into that transition region of the cam track 11 in the chain wheel 9, which is assigned to the lagging angular range β ₂ . In this area, the cam follower 12, so that the distributor pipe 7 and the nozzles 6 fastened thereon, is again transferred into that area of the cam track 11 which has the larger radius. This transfer of the cam follower 12 is accompanied by a lowering of the distributor pipe 7, which is displaceable between the guides 13, and the nozzles 6 into the position shown in FIG. 3.

As a result, the conditions are such that the nozzles 6 briefly from the transport level of the printed products pull back to pass a gripping device 2 and then immediately afterwards return to a position adjacent to the transport level.

In Figures 2 and 3 is in height above the transport level of the printed matter which the manifold 7 or take the nozzles 6 in the lowered position, a sensor 15 is provided which detects the presence of the lowered manifold 7 or the lowered nozzles 6 notes. The one shown in the drawing Embodiment of the sensor 15 is a reflection light barrier. Are equally well suited however, all types of proximity switches or a mechanical one Microswitch, the actuator in Path of movement of the nozzles 6 or one with it moving component is.

If the nozzles 6 and the distributor pipe 7 are lowered, the sensor 15 inputs the mixing device 8 Switch-on signal. The mixing device 8 then delivers the powder-air mixture through the flexible hose 16 to the distributor pipe 7, from which they go through the nozzles 6 emerges in the direction of the printed products. Poses the sensor 15, on the other hand, as shown in FIG. 2, fixed, that the nozzles 6 and the manifold 7 for passage a gripping device 2 are raised up there he to the mixing device 8 a shutdown signal, so that no powder is blown out of the nozzles 6 during this time becomes.

In the embodiment shown in Figures 2 to 4 is the cam device which is lifting and lowering of the nozzles 6 causes as a cam track 11 configured two opposite cam surfaces 11a and 11b. The cam follower 7 is thus both in Direction upwards as well as downwards between the two cam surfaces 11a and 11b positively. At an embodiment not shown in the drawing on the other hand, only the closer to the center of the Sprocket 9 arranged (inner) cam surface 11a intended. The nozzles 6 and the manifold 7 are by a pretensioner, e.g. a feather, after applied above, so that the cam follower 12 without Counter-guidance is in contact with this one cam surface 11a remains.

In another, not shown in the drawing Embodiment of the powder dusting device 4 takes place the control of the lifting and lowering movement on electronic Ways. For this purpose, the distributor pipe 7 with the nozzles 6 on a pneumatic cylinder or other linear actuator (e.g. a magnetic drive), which is able to vertical manifold 7 and nozzle 6 to move between two positions. The Approach of a gripping device 2 to the nozzles 6 by a first sensor, e.g. B. a (reflection) light barrier, detected. This first sensor then enters first signal to the lifting device, which then the Nozzles 6 and the manifold 7 in the upper position moves. If the gripping device 2 then has the nozzles 6 happens, it passes through a second sensor, which is similar how the first sensor can be constructed. This second The sensor indicates when passing the gripping device 2 Lifting device sends a second signal, following which the nozzles 6 and the distributor pipe 7 back into the transport plane of the printed products returns to the adjacent position. In this embodiment, the sensors which act on the lifting device, also for switching on and off the mixing device 8 can be used.

Instead of two sensors, one in front and one others after the nozzles 6 (seen in the transport direction) is arranged, it is also possible to have only one, sensor positioned in front of the nozzles. That of this when a gripping device passes by generated first signal is not only the lifting device (which moves the nozzles 6 and 7 up) but also fed to a timer. This timer generated after a certain period of time, within which has passed the gripping device 2 through the nozzles 6, a second signal which gives the lifting device the command there, nozzles 6 and manifold 7 down again lower. In this case too, it is possible Sensor signal and the output signal of the timer to Activate the mixing device 8 to use this Way to ensure that the powder-air mixture only then emerges from the nozzles 6 when this is in the lowered position.

In the above described with reference to Figures 2 to 4 Embodiment of the powder moistening device 4 becomes a complete nozzle assembly consisting of a distributor pipe 7 and the nozzles 6, back and forth in the vertical direction moved. In this case, a single flexible one is sufficient Hose 16, which is the connection between the Mixing device 8 and the manifold 7 produces. It may be beneficial to reduce the moving masses, the manifold 7 stationary on Attach machine frame and only the nozzles that are in in this case by a very light connecting rod are held together to reciprocate vertically. In this embodiment of the invention everyone leads Nozzle a flexible hose to the manifold.

In the example above, the movement was of the nozzles between the two positions that they face the transport level can assume a linear. The Controlling the sequence of movements is successful with one another embodiment of the invention, which is shown in FIG 5 is even easier:

In this the lifting device comprises a double-armed Lever 17, on one arm 18 of which the nozzles 6 are arranged are and the other arm 19 of a cam surface 11a, 11b is driven, for which purpose it is driven by a drive pin 20 engages in the cam track 11. The lever 17 is on a pin 21 fixed to the frame.

The sprocket 9 rotates the cam track 11 synchronously Movement of conveyor chains 1, and as a result obtained the nozzles swing from one to the other Position. As with the exemplary embodiments described above the cam track 11 is attached to the chain wheel 9, the extent of which is the distance between two successive ones Gripping devices 2 corresponds. The phase position of the sprocket 9 is in the assembly on the phase position the gripping devices 2 matched, so that again it is ensured that the nozzles 6 during the passage a gripping device 2 each by a sufficient Distance from that covered by the printed matter Web to be lifted off.

Claims (14)

1. Powder dusting device for a printing press having

   a) a plurality of nozzles, via which a powder-transport air mixture is directed towards the printed products which are moved past by gripping devices of the transport System of the printing press;

   b) a mixing device, in which the powder is blended with air to produce the powder-transport air mixture;

   c) at least one connecting line, which connects the mixing device to the nozzles,
   characterized by

   d) a lifting device (9 to 13) capable of moving the nozzles (6) to and fro between two positions, namely

   da) a first position relatively far removed from the transport plane of the printed products
   and

   db) a second position situated relatively close to the transport plane of the printed products,

   and

   e) a control device (11, 12), which detects the position of the gripping device (2) and cooperates with the lifting device (9 to 13) in such a way that the latter moves the nozzles (6) into the first Position so long as a gripping device (2) is situated in the vicinity of the nozzles (6) and moves the nozzles (6) into the second position when the gripping device is situated a sufficient distance away from the nozzles (6).
2. Powder dusting device according to claim 1, characterized in that the lifting device and the control device are combined in a cam mechanism (9 to 13), which comprises:

   a) at least one chain wheel (9) which cooperates with a conveying chain (1) of the transport system;

   b) at least one self-contained cam surface (11a, 11b) driven by the chain wheel (9);

   c) at least one cam following element (12), which is connected to the nozzles (6) and cooperates with the cam surface (11a, 11b);

   d) a guide (13), which guides the nozzles (6) along the path between their two positions.
3. Powder dusting device according to claim 2, characterized in that two parallel cam surfaces (11a, 11b) are provided, which form a cam track (11), in which the cam following element (12) is accommodated.
4. Powder dusting device according to claim 2, characterized in that only one cam surface is provided and that the cam following element is pressed by a preloading device against the one cam surface.
5. Powder dusting device according to claim 1, characterized in that the lifting device is mechanically separate from the control device and that the latter comprises at least one first sensor, which is disposed on the transport plane and, when a gripping device approaches the nozzles, supplies a first signal to the lifting device, which causes the lifting device to move the nozzle into the first position.
6. Powder dusting device according to claim 5, characterized in that the control device comprises a second sensor, which is disposed on the transport plane and, when a gripping device moves away, supplies a second signal to the lifting device, which causes the lifting device to move the nozzles into the second position.
7. Powder dusting device according to claim 5, characterized in that the control device comprises a timing element, which is triggered by the first signal of the first sensor and, after a specific time interval has elapsed, produces a second signal, which is supplied to the lifting device and causes the latter to move the nozzles into the second position.
8. Powder dusting device according to one of the preceding claims, characterized in that the nozzles (6) are rigidly connected to a distributing pipe (7) and together with the latter form a movable unit, which is connected by a flexible tube (16) to the mixing device (8).
9. Powder dusting device according to one of claims 1 to 7, characterized in that the nozzles are connected to a light support rod so as to form a movable unit and each nozzle is connected by a flexible tube to a stationary distributing pipe, which is in turn connected to the mixing device.
10. Powder dusting device according to one of the preceding claims, characterized in that it comprises a sensor (15), which detects the position of the nozzles (6) and produces an output signal, which sets the mixing device (8) in operation only so long as the nozzles (6) are situated in the second position.
11. Powder dusting device according to claim 1, characterized in that the lifting device displaces the nozzles in a swivelling motion between the two positions.
12. Powder dusting device according to claim 11, characterized in that the lifting device comprises a one-or multi-armed lever, which at a first point carries the nozzles (6) and acting upon which at a second point is a cam surface (11), which is driven in step with the conveying speed of the printed products.
13. Powder dusting device according to one of claims 2 to 12, characterized in that the cam surface (11a, 11b) executes one revolution for advancing the conveying chain (1) by a distance corresponding to the spacing of two successive gripping devices (2).
14. Powder dusting device according to claim 2 in combination with claim 13, characterized in that the circumference of the chain wheel (9) corresponds to the spacing of successive gripping devices (2).

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