EP0520945B1 - Method and device for storing and equalising printed products in shingled formation and for closure of gaps in said formation - Google Patents

Description

The invention is in the field of further processing of printed products and relates to a method and a device according to the preamble of the corresponding independent claims, which serve to produce flat products, in particular multilayer, folded printed products in scale formation during transport on a transport route provided for buffering to buffer and cycle as needed, and to close gaps in the scale formation.

Printed products, in particular multilayer, folded printed products, are laid out for further processing, for example by rotary machines or from winding in scale formation. It is advantageous to switch buffers between the design of such shingled streams and their further processing for two reasons: first, the propagation of disturbances and systematic irregularities upstream can be avoided or alleviated, secondly, gaps in the streams can be closed and thirdly, the shingled stream can be clocked simultaneously . In the event of a malfunction in the further processing, which thereby runs more slowly or even stops, the buffer absorbs the products which arise during an unavoidable reaction time for a reaction of the feeder or even allows a shorter processing interruption by only one Slow down the supply and fill the buffer accordingly, which saves stopping and re-accelerating large masses. If the further processing contains systematic irregularities, such that the supplied product is not used continuously for the further processing step, such as for example when inserting it in a personalized manner, the supply can nevertheless continuously supply products into the buffer with a correspondingly lower output. In the case of trouble-free, continuous further processing, it is nevertheless advantageous to work with a buffer, since gaps in the shingled stream supplied can be eliminated without affecting the course of further processing. The buffer thus serves as a collecting station for errors and irregularities both upstream and downstream.

Buffer methods and devices of this type are also described, for example in US Pat. 4887809, 4892186 and 4201286 by the same applicant. The buffer systems described in these documents all work with buffering agents (clamps, hooks, grippers, brake cams) which act on the printed products of the shingled stream over a buffering section of constant length, i.e. transport them more or less actively, the number of buffering agents on the buffering section and so that the distance between the buffer means is variable. When the buffer is full, the mean distance between the buffer means on the buffer section is Heiner than when the buffer is empty, since when the buffer is full more buffer means are positioned on the buffer section. The buffer systems described thus work on the basic idea of the buffer section with a constant length and a variable distance between the buffer means. The variable distance between the buffer means is realized, for example, by free movement of the buffer means along a movement path, whereby they are pushed by the subsequent buffer means, or by elastic connections between the buffer means, which are pulled by the leading buffer means.

All these buffer systems described have the disadvantage that they have individually guided elements which cannot be driven by common traction means, such as chains, for example, and which have to be re-clocked after the buffering, and that the printed products are transferred to the buffer means in most cases have to be transported over the buffer section, which usually requires special spatial arrangements. In addition, the systems described require a great deal of sensor technology geared to the printed products, not only to measure the fill level of the buffer for controlling the design and / or further processing, but also to detect and close gaps in the shingled stream supplied. Such sensors must be reset when changing the product format, for example.

Publication CH-A-5805311, on the other hand, describes a device with which the distances between printed products which are conveyed as a scale formation on a means of transport are made more uniform by the fact that they are slowed down by equidistant braking means and at a distance which is smaller than that Distance of the printed products in the original scale formation. So that the device can also compensate for larger irregularities, the brake means are pivoted one after the other into the transport path of the printed products, and always when a printed product hits the leading brake means and the latter is braked.

Such a device can now obviously also be used in the sense of a buffer, the braking means serving as buffering means which are not spaced apart from one another as in the case of the buffer devices mentioned above. The buffer means are at a fixed distance from one another, but due to the activation of the buffer means initiated by the printed products, the number of buffer means that are active is variable, that is, it is a buffer with a variable length of the buffer path and a constant distance between the buffer means .

The stream of shingles is transported over the route provided for buffering essentially on a conveyor belt which can be easily switched into the transport routes of other conveyor belts. In order to implement the variable length of the buffer section, the section intended for buffering is functionally divided into two sections, into a downstream, effective buffer section and an upstream reserve section, the boundary (transition point) between these two sections moving depending on the fill level of the buffer , that is, the relative length of the two sections is variable. When the buffer is full, the reserve section has a minimal length, when the buffer is empty, the buffer section has a minimal length. The printed products are transported in shingled formation over the entire route, first by means of a conveyor belt over the reserve route and then with the help of the buffering agents over the buffer route. The speed and product distance on the reserve route can depend on the supply performance, the further processing performance and also on the fill level of the buffer, while the product distance on the buffer route is fixed and the speed is determined by the further processing performance. The scale distances and the speed on the buffer section are always smaller than on the reserve section.

Such a buffering process can best be compared to a liquid buffer in the form of a vessel with inflow and outflow and a different level depending on the degree of buffer filling. In this case too, the degree of filling has no influence on the properties of the liquid in the buffer vessel. The only thing that changes with the degree of filling is the liquid level or in other words the path of the supplied water to the liquid surface in the buffer vessel (reserve section) and the path of the liquid from this surface to the outlet (buffer section).

Such a buffer system buffers a scale flow without converting it into another form of delivery flow, but only by reducing the scale distance to a length that is characteristic of the buffer and cannot be changed, the length of the buffer depending on the number of printed products to be buffered. There are only two different printed product distances on the transport route provided for buffering, each in the area of two different types of transport, the transport by means of a conveyor belt on the reserve route and the transport with the buffer means on the buffer route.

Such a buffering method is implemented by a conveyor belt and the buffer means, both of which run over the entire distance intended for buffering, the buffer means only acting on the buffer products on the printed products and being ineffective on the reserve route, so that the conveyor belt on the reserve route is solely for is responsible for the transport. To carry out such a method, buffer means with a constant spacing are required, which act on the printed products over a variable distance. These buffering means are implemented as means which change their state at the transition point from the reserve section to the buffer section in such a way that they have no effect on the stream of shingles before the transition point, after the transition point but act on the printed products in such a way that the transporting effect of the conveyor belt is completely eliminated or at least restricted.

The buffering means are designed in such a way that they switch from a print product to be buffered when they arrive at the transition point from the reserve section to the buffer section from the ineffective to the active state.Therefore, no sensors are required for the effective buffering operation and the fill level of the buffer can simply be removed from the state (effective or ineffective) of the buffering means at individual points on the route provided for buffering and can be used for the control of feed performance and / or further processing performance. In particular, there is no need for a sensor system that is oriented to the printed products, which would have to check, for example, whether a buffering agent is transporting a printed product or not, a sensor system that would have to be reset when the product format changes.

The disadvantage of the known buffer method (publication CH-A-580531) with variable buffer length and constant buffer medium spacing is that the transport means acts on one side (bottom) of the scale formation and the buffer medium on the other side (top). As a result, the method cannot be used for scale formations with leading edges below and it is difficult to provide further functions in the same area.

The object of the invention is to provide a method for buffering and clocking printed products conveyed in a scale formation and for closing gaps in this scale formation. Another object of the invention is to provide a device by means of which the method can be carried out.

These objects are achieved by the method according to the invention and by the device according to the invention, both of which are defined in the patent claims.

Figur 1

ein Schema des erfindungsgemässen Verfahrens;

Figur 2

eine beispielhafte Ausführungsform eines erfindungsgemässen Puffermittels in seinen verschiedenen Zuständen, quer zur Transportrichtung gesehen;

Figur 3

ein Puffermittel gemäss Figur 2, quer zur Transportrichtung geschnitten;

Figur 4

ein Schema einer für die Pufferung vorgesehenen Transportstrecke;

Figur 5

Ein Anwendungsbeispiel für die erfindungsgemässe Puffervorrichtung.

The method according to the invention and an exemplary embodiment of the device according to the invention are described in detail with reference to the following figures. Show:

Figure 1

a diagram of the inventive method;

Figure 2

an exemplary embodiment of a buffering agent according to the invention in its various states, seen transversely to the direction of transport;

Figure 3

a buffering agent according to Figure 2, cut transversely to the transport direction;

Figure 4

a diagram of a transport route provided for buffering;

Figure 5

An application example for the buffer device according to the invention.

Figure 1 shows a schematic diagram for the buffer method according to the invention. It shows a section of a transport route provided for buffering with a conveyor belt 10, on which a shingled stream of printed products 11.1 / 2/3 .... is conveyed in the transport direction F, and buffering means 12.1 / 2/3/4 ..... , for example in the form of brake cams.

The transport route provided for buffering is functionally divided into two sections: a buffer route P and a reserve route R, the buffer route P being located in front of the reserve route R in the transport direction. On the reserve route R, the printed products (11.7 / 8/9 ....) are conveyed through the conveyor belt 10 and at an adjustable belt speed v _R , while the buffer means (12.8 / 9/10 ...) are ineffective, for example under the Conveyor belt are sunk. The distance of the printed products d _R on the reserve path R is determined by the speed v _R and by the feed power (Z) of any feed device which is not shown.

On the buffer section P, the product distances d _P and the speed v _{P of} the printed products (11.1 to 11.6) are determined by the speed and distance of the buffering means, since these are effective on this section and act on the printed products, for example by protruding over the conveyor belt and the printed products brake while they are still moving forward from the conveyor belt. The distance d _P between the printed products on the buffer path P corresponds to the fixed distance between the buffer means and the speed v _P becomes in accordance with a further processing performance W set any further processing device, not shown, so that the buffer means pass on the printed products correctly timed at the output of the buffer device.

The function of the buffer device is now as follows: The speed v _P is set in this way and is regulated during operation in such a way that the output power of the buffer corresponds as far as possible to the number of printed products per unit of time required by the further processing. Since the buffer is a small and therefore not very sluggish device, this speed can also be regulated accordingly without difficulties in the further processing performance. The speed v _{R of} the conveyor belt is set such that it is greater than the speed v _P , for example by a factor of 2.5, and such that the distances between the printed products on the reserve path R are greater than those on the buffer path P. The speed v _R can be set constant or proportional to the speed v _P for certain ranges of the feed power, as long as the above-mentioned conditions are met. However, the drives of the conveyor belt and buffering means should not be coupled, since if the further processing stops the buffering means must stop (further processing power is zero), but not the conveyor belt, which can fill up the buffer even when stopped, so that the feed is not stopped got to.

If the scale distance d _{R is} smaller than the distance between the buffering agents d _P , more than one product of each buffering agent is buffered together, which can be a desired process variant depending on the further processing.

Is the further processing power W and the feeding power Z the same size (same number of printed products per unit of time, ie the same cycle) and should the filling level of the buffer is kept constant, the cycle on the reserve line and on the buffer line is the same, i.e. every product on the buffer line (or each buffer medium somewhere on the transport line) covers the distance d _P in the same time as each product the distance d _R on the reserve route. As a result, a new product always arrives at the transition point U when the preliminary product with the corresponding buffering agent has traveled the distance d _P and the next buffering agent is therefore at the same point. This buffering agent becomes effective and brakes the product in such a way that it continues to move at the speed v _P. With such a mode of operation, the transition point between reserve section R and buffer section P will always remain at the same location.

If the supply power Z Heiner than the further processing power W, the cycle time on the buffer line is longer than on the reserve line, i.e. a buffer medium moves by more than the line d _P in the time in which a printed product on the reserve line moves by d _R emotional. A next product will therefore only arrive at the transition point U when a next buffer medium has already moved over this point, and the corresponding printed product will only hit it later or further downstream and will be braked by it. As a result, the transition point U has shifted to the left in the figure, or in other words the buffer path has become shorter and the buffer has become empty. In the event that the feed rate is higher than the further processing rate, the buffer will correspondingly fill up more.

The buffering agents are effective on the buffer section P, that is, they act on a product, on the reserve section R ineffective, that is, they do not act on products. A buffering agent at the transition point U (in the figure, buffering agent 12.7) must be active insofar as it has to brake a next product, but does not yet act on any product, it is not yet effective, it is ready". The buffering means must therefore be designed in such a way that they can assume three states: ineffective (on the reserve route), effective (on the buffer route), ready (at the transition point). According to the invention, an ineffective buffering agent is made available at the transition point by switching the leading buffering agent from ready to effective; a ready buffering agent is activated when it enters the buffer zone by a printed product bumping into it and braking it. This always results in a number of ineffective buffer means (reserve route), a ready buffer means (transition point) and a number of effective buffer means (buffer route) on the entire route, whereby the relative numbers depend on the number of printed products on the entire route.

Both the conveyor belt and the buffer media are moved from the end of the buffer line (handover of the products to further processing) on a return to the beginning of the reserve line. During this return the buffering agents must be switched from effective to ineffective.

Speeds and product distances in the buffer system according to the invention should be set in such a way that each transported printed product encounters a buffer medium before the end of the buffer zone so that it can be passed on to the further processing at an exactly clocked rate, in other words, the buffer zone should always be at least one have effective buffering agent. This is advantageously ensured by the fact that each buffering agent is reliably activated at the exit of the buffer section, for example by the effect of the deflection to the return. Only in this way can the buffer system act simultaneously as a clock generator, with which irregularities in the shingled stream supplied are compensated to a limited extent, and only in this way is it ensured that the buffer function can be resumed automatically after the transport route provided for buffering has been completely emptied or after the buffer has emptied.

The buffer system according to the invention also automatically closes gaps in the shingled stream supplied. Since such a gap no longer comes into contact with the ready buffer medium (transition point), this will continue to move towards the buffer exit before it is activated, that is to say the transition point will move towards the left in the figure or the buffer will be complete otherwise the gap will have no effect on buffering or further processing if there is enough buffer.

The method according to the invention, if it works, as described, with brake cams which can be lowered under the conveyor belt as buffer means, requires a shingled stream in which the leading edges of the printed products are directed downwards, in which case one product is partially covered by the leading products. In such a stream, it is not possible to close gaps that are wider than the respective overlap of two products by simply pushing them open, as would be done in the described method without special aids. Since the products no longer lie one on top of the other in such a large gap, the subsequent product must be pushed under the preliminary product to close the gap, for which appropriate aids are necessary.

FIGS. 2 and 3 show in detail an exemplary embodiment of buffer means according to the invention, as a view transverse to the transport direction (FIG. 2) and cut transversely to the transport direction as a view against the transport direction. It is a retractable under the conveyor belt 10 Brake claw, which, if not sunk, stops the printed products in the middle area of their downward leading edge and slows their movement on the conveyor belt from the speed of the conveyor belt to the lower speed of the buffer means. For this embodiment, the conveyor belt is designed, for example, in the form of two parallel sub-belts, a pull chain 30 with the brake claws being positioned in the central gap between the two sub-belts such that the claws are in their effective and ready (not sunk) state the transport surface of the conveyor belt is sufficient to be moved under the transport surface in its ineffective (sunken) state.

The conveyor belt 10 is only indicated in the two drawings by a level line that designates its transport surface. The pull chain 30 is indicated as a dashed line.

FIG. 2 shows a series of 4 buffer means according to the invention in the form of brake claws 121, 122, 123, 124 (120 and 125 only partially shown), which are to move from right to left in a transport direction F, driven by a pull chain 30 ( indicated in Figure 3). The brake claw 121 is in its effective state, the second brake claw 122 is in its ready state and the two rear brake claws 123 and 124 are in their inactive state, the figure is therefore a representation of the transition point U from the reserve line R to the buffer line P. FIG. 3 shows one Brake claw in its effective or ready state (121, 120 or 122).

Each brake claw consists of a claw body 20 in which two chain pins 23 and 25 are rotatably mounted in two guides 24 and 26. The guide 24 of the rear chain pin 23 in the transport direction is slot-shaped, the guide 26 of the front chain pin 25 in the transport direction is designed as an angled slot, such that the claw body 20 can move laterally relative to the chain pins 23 and 25 essentially parallel to the transport direction and in its rearward position with respect to its lateral movement rear chain pin 23 can be pivoted. This pivoting movement is limited by the front guide 26 in such a way that, in an upper extreme position of a claw 21 attached to the front of the claw body 20, it projects over the conveyor belt, in a lower extreme position of the claw 21 it is sunk under the conveyor belt.

The claw 21 is pressed into its upper position and the claw body 20 into its rear position by a force means, for example a spring 28. The spring 28 can be, for example, a coil spring arranged around the chain pin, which is clamped on the claw body 20 with the aid of two ends extending from the screw shape between the chain and a corresponding spring cam 27. The power means can also be a permanent magnet which is arranged in the front, lower region of the claw body 20 in such a way that the claw 21 is pulled into its upper pivoting position and the claw body 20 into its rear position by the magnetic attraction between the magnet and the chain pin 25.

The claw body 20 carries the claw 21 at the front in the transport direction and a holding cam 22 and a recess 29 at the rear. The two guides 24 and 26 are arranged in the claw body in such a way that the axis of the pivoting movement (chain pin 23) lies far to the rear, so that during a pivoting movement the The change in position of the claw 22 and the holding cam 21 is significantly greater than that of the indentation 29.

The brake claws are dimensioned and arranged on the pull chain 30 in such a way that they overlap in a transport direction on a straight line. This overlap enables an interaction between the holding cams 22 on the front sides of the claw bodies 20 with the corresponding indentations 29 on the rear side of the leading claw body 20, but only if the holding cams 22 and the indentation 29 are essentially at the same level. This is the case when the claw 21 is in its lower pivot position. The pivot position of the indentation 29 is insignificant, that is to say that a holding bolt 22 pivoted into the lower position can interact with an indentation 29 of a leading brake claw with the claw 21 pivoted downwards or upwards. The overlap of the claw bodies in the transport direction is smaller than the amount of lateral movement that a claw body can perform.

The claw 21 is pressed into its upper pivot position by the spring 28 if it is not held in the lower pivot position by the interaction of the holding cam 22 with the indentation 29 of a leading brake claw. A brake claw with claw 21 in the upper pivot position can be moved from the rear to the front position by a printed product striking it from behind at a higher speed.

• Der Krallenkörper 20 ist in seiner vorderen Stellung, die Kralle 21 durch die Kraft der Feder 28 nach oben geschwenkt (121). Dies ist der wirksame Zustand der Bremskralle (121). Eine Interaktion zwischen dem Haltenocken 22 und der Einformung 29 einer vorlaufenden Bremskralle (120) ist nicht möglich, da diese nicht auf gleichem Niveau sind. Eine Interaktion der Einformung 29 mit dem Haltenocken 22 einer folgenden Bremskralle (122) ist nicht möglich, da die folgende Bremskralle in ihrer vorderen Stellung mit nach unten geschwenkter Kralle 21 sein müsste, eine Stellung, die sie nicht einnehmen kann.
• Der Krallenkörper 20 ist in seiner hinteren Stellung, die Kralle 21 durch die Kraft der Feder 28 nach oben geschwenkt (122). Dies ist der bereite Zustand der Bremskralle (122). Eine Interaktion zwischen dem Haltenocken 22 und der Einformung 29 der vorlaufenden Bremskralle (121) ist nicht möglich, da diese nicht auf gleichem Niveau sind. Eine folgende Bremskralle (123) kann nur in ihrer hinteren Stellung sein und eine Interaktion zwischen der Einformung 29 und dem Haltenocken 21 dieser folgenden Bremskralle ist möglich, wenn deren Kralle in ihrer unteren Schwenkposition ist.
• Der Krallenkörper 20 ist in seiner hinteren Stellung, die Kralle 21 durch den Druck des Haltenockens 22 einer folgenden Bremskralle gegen die Kraft der Feder 28 nach unten geschwenkt (123 bzw. 124). Dies ist der unwirksame Zustand der Bremskralle (123 oder 124). Eine Interaktion zwischen dem Haltenocken 22 und der Einformung 29 einer vorlaufenden Bremskralle (122 bzw. 123) ist nur möglich, wenn diese auch in ihrer hinteren Position ist, das heisst, es besteht keine Interaktion zwischen den Krallen 122 und 123, wohl aber zwischen 123 und 124. Eine folgende Bremskralle (124 bzw. 125) kann nur in ihrer hinteren Stellung sein und eine Interaktion zwischen der Einformung 29 und dem Haltenocken 22 dieser folgenden Bremskralle (124 bzw. 125) ist notwendig, um die Bremskralle 123 bzw. 124 in dieser Stellung zu halten.

The brake claws 20 have three possible extreme positions:

• The claw body 20 is in its forward position, the claw 21 is pivoted upward by the force of the spring 28 (121). This is the effective state of the brake claw (121). An interaction between the holding cam 22 and the indentation 29 of a leading brake claw (120) is not possible since these are not at the same level. An interaction of the indentation 29 with the holding cam 22 of a following brake claw (122) is not possible because the following brake claw is in its should be in the front position with the claw 21 pivoted downwards, a position which it cannot assume.
• The claw body 20 is in its rear position, the claw 21 is pivoted upwards by the force of the spring 28 (122). This is the ready state of the brake claw (122). An interaction between the holding cam 22 and the indentation 29 of the leading brake claw (121) is not possible since these are not at the same level. A following brake claw (123) can only be in its rear position and an interaction between the indentation 29 and the holding cam 21 of this following brake claw is possible if the claw is in its lower pivot position.
• The claw body 20 is in its rear position, the claw 21 is pivoted downward by the pressure of the holding cam 22 of a following brake claw against the force of the spring 28 (123 or 124). This is the ineffective state of the brake claw (123 or 124). An interaction between the holding cam 22 and the indentation 29 of a leading brake claw (122 or 123) is only possible if it is also in its rear position, that is, there is no interaction between the claws 122 and 123, but probably between 123 and 124. A following brake claw (124 or 125) can only be in its rear position and an interaction between the indentation 29 and the holding cam 22 of this following brake claw (124 or 125) is necessary to the brake claw 123 or 124 in to hold this position.

In their ineffective state, the brake claws move through the reserve section R, in their effective state via the buffer section P. The following happens at the transition point U: The already buffered print products are braked by brake claws and move in the conveying direction at a speed which is less than the speed of the conveyor belt, towards the end of the buffer line. A brake claw now observed follows the last brake claw with the printed product of the buffer section. A next printed product is moved from behind at the speed of the conveyor belt against the observed brake claw and hits it once. The observed brake claw has an upwardly pivoted claw 21, since the leading brake claw has been moved into its forward position by the last printed product of the buffer section and an interaction between the observed brake claw and the leading brake claw is no longer possible. By braking the printed product now striking the observed brake claw, this is also moved into its forward position (effective state), so that the interaction with the following brake claw is released and the claw 21 of this following brake claw is pivoted into its upper position (ready state) . The switching process from the ineffective to the ready and from the ready to the active state at the transition point is therefore only triggered by the printed products and requires no external control and therefore no sensors.

As long as the buffer is working properly, each brake claw passes the end of the buffer section in its effective state. This is the case as long as the buffer always contains at least one printed product. In the event that the buffer runs empty, for example due to Heiner feed capacity or if the feed is interrupted, it is essential for the buffer function to resume automatically that the brake claws at the end of the buffer section are switched to their effective state even without print products to be buffered. This is achieved by appropriately designing the deflection point, which deflects the brake claws onto their return strand. The deflection radius of the interaction point must be larger than the deflection radius of the chain bolts that no interaction is possible during the deflection.

The brake claws must be repositioned during the redirection after the end of the buffer line, during the return run or during the redirection to the beginning of the reserve line so that they enter the reserve line in an ineffective state. This is achieved, for example, in that they are moved to their rear state by a corresponding movement template during the deflection after the end of the buffer section and are moved into the lower pivot point of the claw with a different template during the deflection into the beginning of the reserve section, so that they are kept ineffective by the template until the interaction occurs on the straight-line reserve route. In this way, the brake claws pass the return run in the ready state, which is only possible for one brake claw on the forward route. It would just as well be possible to move the brake claws through the return section in an effective state and to arrange the corresponding template only at the second deflection point.

Brake claws, which, as already mentioned, carry a magnet instead of a spring 28 (FIG. 2), can be carried out at the deflection points via corresponding steel links, which are designed in such a way that the magnetic attraction between the permanent magnet and the Steel link is greater than the magnetic attraction between the permanent magnet and the chain pin and that magnetic forces are generated in the area of the first deflection, which bring the brake claws into their rear position, at the second deflection such that magnetic forces are created that push the brake claws into it Swivel the swivel position in which the claw is down.

The brake claws according to the invention can, as shown in FIG. 3, be arranged centrally on the chain pins, that is to say between the link plates, or else on one side, that is to say outside the link plates. If arranged on the side, the brake claws can be installed by simply attaching them. Commercially available chains can be used. The brake claws are advantageously made of plastic.

Instead of brake claws, grippers are also conceivable as a buffer. If brake claws are used as a buffering means, it is advantageous to arrange the distance provided for buffering slightly decreasing, but it can also be horizontal, but not increasing. If grippers are used as a buffer, there are no restrictions with regard to the location of the transport route provided for buffering.

FIG. 4 shows schematically an entire transport route equipped for buffering, which is also equipped with an auxiliary device necessary for closing larger gaps in the shingled stream. This figure is also to be used to describe how a corresponding device is monitored and controlled. Parts mentioned in connection with the figures already described are identified by the same reference numbers.

The conveyor belt 10 runs over two deflection rollers (not visible in the figure). The traction element (30) with the buffering means 12 also runs over two deflection rollers 31 and 32. An auxiliary device 40 for closing larger gaps in the stream of shingles entering the buffering is arranged over the transport section equipped for buffering (preheating section of the buffering means).

In the area of the transport route equipped for buffering (forward run of the conveyor belt 10) there are at least two sensors 13.1 / 2 in the area of the entrance of the reserve route and in the area of the exit of the Arranged buffer route, which generate signals to determine the state of the passing buffer means. These are, for example, light barrier sensors that are interrupted or not by parts of the buffering agent, depending on the state. If the output sensor 13.1 reports ineffective buffer means, this means that the minimum tolerable buffer filling is not reached. If the input sensor 13.2 reports effective buffering agents, this means that the maximum tolerable buffer filling has been exceeded. From such messages from sensors 13.1 / 2, control signals are generated for an increase or decrease in the feed power and / or an increase or decrease in the processing power and corresponding control signals for changing the speeds v _{P of} the buffering means and / or v _{R of} the conveyor belt. More than two sensors can also be arranged and the controls can be carried out in stages accordingly. The messages from sensors 13.1 and 13.2 and corresponding additional sensors can also be used to detect malfunctions.

The auxiliary device 40 has a carriage 41 which can be moved over the entire transport path and which carries two sensors 42.1 and 42.2 and a jack 43. The two sensors 42.1 / 2 are designed in such a way that they detect interruptions in the shingled stream (gaps larger than the overlap of the printed products), the sensor 42.1, which is at the rear in the transport direction, detects the beginning of a gap, and the sensor 42.2 at the front in the transport direction the end of such a gap . The lifter 43 is designed in such a way that when it is guided in the transport direction over an interruption in the shingled stream, it reaches under the product transported before the interruption and lifts it off the conveyor belt and that it can be pulled over the products when it is guided against the transport direction, without moving it. For this purpose, the lifter 43 is arranged such that its end is positioned directly above the conveyor belt in the rest position and that it can be swung out of this rest position in the transport direction. The jack 43 is arranged such that its end lies between the areas of the two sensors 42.1 and 42.2.

The function of the auxiliary device is as follows: Your starting position is at the entrance to the transport route. As soon as the rear sensor 42.1 detects the beginning of an interruption, the auxiliary device is put on standby. As soon as the interruption reaches the area of the front sensor 42.2, the carriage 41 moves in the transport direction at the same speed as the interruption and printed products and thus always remains above the interruption. It moves until it reaches the buffered products, more precisely until the rear sensor 42.1 is positioned over the buffered products, that is to say it no longer sees an interruption. This means that the end of the lifter has already lifted the buffered products or at least the rear edge of the last buffered product and the product following the interruption has been pushed underneath. The carriage stops moving forward and is then moved back to its starting position. If he finds another interruption on his way, the procedure is the same.

The carriage 41 is driven by an electric, pneumatic or hydraulic linear motor.

FIG. 5 shows an application example for the buffer method according to the invention and the buffer device according to the invention. This is the supply to a collecting drum 53 from a winding station 50 with two windings 50.1 and 50.2, one of which is unwound (50.1), while in the other winding position (50.2) an empty winding core can be exchanged for a new winding . The device 51 according to the invention is connected between the winding station 50 and a transfer station 52.

The shingled stream S.1 laid out by the unwinding roll 50.1 is guided on a conveyor belt 50.3 to the buffer device 51. In most applications, the speed of the feed belt 50.3 will be lower than the speed of the buffer belt 51.1, so that the shingled stream S.1 is pulled apart with larger shingled gaps at the transition from the feed belt 50.3 to the buffer belt 51.1 to a shingled stream S.2. It is advantageous at this transition point to press the shingled stream onto the conveyor belts with a pressure roller 50.4 or a pressure belt. The shingled stream S.2 passes through the buffer device 51 in that, depending on the buffer fill level, it is braked sooner or later by buffering means 51.2 and is set to a smaller shingled distance (S.3). At the exit of the buffer, the printed products are passed to a transfer station 52, the scale stream S.3 being pulled apart again at the transition point to a scale stream S.4 with a greater scale distance. At this transition point, too, it is advantageous to press the printed products onto the conveyor belt using a pressure roller or pressure belt (not shown in the figure). Then the shingled stream S.4 is diverted to a shingled stream S.5 with the reverse position of the printed products and then converted to a conveying stream S.6 with grippers by transferring the individual printed products to corresponding grippers. The flow S.6 with grippers is then guided to the collecting drum 53, where the printed products are collected into groups of different printed products.

It is obviously not imperative that the transport route through which the buffer means 51.2 and the conveyor belt 51.1 have the same length. It is quite conceivable that the conveyor belt 51.1 is longer than the pulling element of the buffering means and projects above it upstream. The transport route provided for buffering is then only as long as the transport route with buffering means, the beginning of the transport route of the conveyor belt being only a feed route.

Suitable winding stations for the application of the device according to the invention illustrated in FIG. 5 are described, for example, in US Pat. 4898336, corresponding transfer stations in US Patent No. 4201286 and corresponding collecting drums in US Patent No. 4684116 by the same applicant.

Claims (18)

1. Method for the buffer storage and timing of printed products conveyed in scale formation, particularly multilayer, folded printed products, and for closing gaps in such a scale formation during the conveying of the latter over a conveying path, the scale formation of printed products being conveyed on a conveyor belt (10) with the speed v_R over a first part of the conveying path provided for buffer storage, namely the reserve path (R), the printed products then being decelerated at a transition point (U) by the action at this point of buffer storage means (12) on the individual printed products to a speed v_P, which is lower than the speed v_R, so that the scale spacing (d_R) is set to the fixed spacing (d_P) of the buffer storage means (12), the printed products of the scale formation by the action of the buffer storage means or by a combined action of the conveyor belt (10) and buffer storage means (12) then being conveyed over the second part of the conveying path provided for buffer storage, the effective buffer storage path (P), and in which the position of the transition point (U) on the conveying path provided for buffer storage being automatically displaced as a function of the number of printed products on this path, characterized in that the printed products of the scale formation are conveyed with bottom leading edges on the conveyor belt (10), that the buffer storage means (12) act in decelerating manner from below on said bottom leading edges and that gaps in the scale formation are closed in that in the vicinity of the transition point (U) the printed products in front of the gap are raised from the rear and the printed products following the gap are moved under the same by the conveyor belt (10).
2. Method according to claim 1, characterized in that the conveyor belt (10) and buffer storage means (12) are guided over the entire conveying path provided for buffer storage and that the buffer storage means (12) at the start of the conveying path are in an inactive state and during the movement thereof along the conveying path are switched by the printed products to be buffered into a ready state and then into an active state, in that they cover the remainder of the conveying path and act in each case on at least one printed product.
3. Method according to claim 2, characterized in that there is an interaction between the buffer storage means in the inactive state which is cancelled out by a printed product catching up a buffer storage means, provided that this is permitted by the state of the preceding buffer storage means.
4. Method according to claim 3, characterized in that each buffer storage means during its passage through the conveying path provided for buffer storage is switched by the switching process of the buffer storage means in front of it from the ready into the active state and from the inactive into the ready state and it is then switched by a catching up printed product from the ready into the active state, the interaction with the following buffer storage means being cancelled out and said following buffer storage means is consequently switched from the inactive to the ready state.
5. Method according to one of the claims 2 to 4, characterized in that the buffer store fill level is monitored in that at at least two points of the conveying path the state of the passing buffer storage means is monitored.
6. Method according to one of the claims 1 to 5, characterized in that by a forced switching process at the end of the conveying path each buffer storage means is switched into the ready state, so that the buffer storage function can be automatically resumed following a supply interruption through which the conveying path provided for buffer storage has run empty, or after a running empty of the buffer store.
7. Method according to one of the claims 1 to 6, characterized in that during their deflection to a return strand, during said return strand or during their deflection to the forward strand, the buffer storage means are switched from the active to the inactive state.
8. Method according to one of the claims 1 to 7, characterized in that gaps in the scale formation are detected by sensors (42.1, 42.2) movable over the conveying path and are followed to the transition point (U), that at the transition point (U) by a lifter (43) movable with the sensors the products in front of the gap are raised from the rear and by the conveyor belt (10) the printed products following the gap are moved below the same.
9. Apparatus for performing the method according to one of the claims 1 to 8, said apparatus having a conveyor belt (10), with which a scale flow can be conveyed over the conveying path, and on the same conveying path or on at least part thereof there is a tension member (30) with equidistantly fixed buffer storage means (12.1/2/3...) pivotable into the vicinity of the scale formation, the tension member being drivable at a lower speed than the conveyor belt, characterized in that the tension member (30) and buffer storage means are so arranged that the buffer storage means for exerting a braking action on the leading product edges on the conveyor belt (10) can be pivoted into a position in which they extend over the conveying surface of the conveyor belt (10) and can be lowered into a position in which they are below the conveying surface and that the apparatus has an auxiliary device (40) for closing gaps in the scale formation which can be moved over the conveyor belt and along the conveying path and which is provided with a lifter (43) and sensors (42.1, 42.2).
10. Apparatus according to claim 9, characterized in that the conveyor belt (10) comprises two parallel-running partial belts with an intermediate gap and that the tension member with the buffer storage means (12.1/2/3...) is so arranged in the vicinity of said gap.
11. Apparatus according to claim 10, characterized in chat the tension member is constructed as a tension chain (30) and the buffer storage means (12.1/2/3/4....) as brake claws (120 to 125) and that the brake claws are laterally movable relative to the tension chain and pivotably fixed to the latter.
12. Apparatus according to claim 11, characterized in that the brake claws (120 to 125) are so arranged on the tension chain (30) that they overlap in their extension in the conveying direction.
13. Apparatus according to one of the claims 9 to 12, characterized in that for closing gaps in the scale formation the auxiliary device (40) has a slide (41), on which are arranged two sensors (42.1, 42.2) directed against the conveying path and one lifter (43) extending directly above the conveying surface.
14. Apparatus according to one of the claims 9 to 13, characterized in that in the vicinity of the deflections of the tension member with the buffer storage means switching means are provided with which the buffer storage means can be switched from their active to their inactive state.
15. Apparatus according to claim 16, characterized in that the switching means are movement patterns and/or steel links.
16. Apparatus according to one of the claims 11 to 15 having a tension chain with brake claws, characterized in that each brake claw (120 to 126) is guided by a front guide (26) and a rear guide (24) on two adjacent chain studs (25, 23), both guides being constructed in such a way that the brake claw is movable relative to the tension chain parallel to the conveying direction and the front guide (26) is so designed that the brake claw is pivotable about the rear chain stud (23), that each brake claw has on a claw body (20), in which the guides (24, 26) are located, at the front in the conveying direction a claw (21) and a retaining cam (22) and at the rear an indentation (29) and that with each brake claw is associated a force means, which presses it into its rear position and into the upper position of the claw (21) and that the brake claws are so arranged on the chain that in the case of a linear conveying path of the retaining cams (22) a following brake claw can be interacted with the indentation (29) of a preceding brake claw at least in one of the possible pivoting positions of the brake claws.
17. Apparatus according to claim 16, characterized in that the force means is a spring (28) stretched between the chain and the brake claw.
18. Apparatus according to claim 17, characterized in that the force means is a permanent magnet located in the front, lower area of the brake claw.

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