EP0045713B1 - Device for diverting waste sheets from the main stream - Google Patents

Description

The invention relates to a waste switch for a transport path which receives a scale web made of folded paper products, in particular for a transport path arranged between a folder and a downstream delivery station, which consists of a plurality of belt paths arranged one behind the other with conveyor belts running around belt rollers, at least the belt roller at the rear in the transport direction of the one The space between two consecutive belt rolls delimiting belt sections is movably mounted and its distance from the adjacent belt section can be changed by means of an actuating element which can be activated by a control device.

In a known arrangement of this type, the space between two successive belt sections can be changed to form a switch by shortening or lengthening the respective rear belt section. For this purpose, the front belt roll of this rear belt section is moved back and forth at a constant height. To accomplish the required length compensation, the belts are guided in the region of their return branch over a dancer roller wrapped in a loop, which is moved in counteract to the reciprocating belt roller. The lengthening or shortening of the rear belt section and, accordingly, the shifting of the belt roller and the dancer roller must take place very quickly in order to achieve a clean separation at the beginning or at the end of the section of the scale web consisting of waste products. Accordingly, high inertial forces occur, which cause jerky blows in an undesirable manner and result in considerable wear. At the same time, a relatively strong dimensioning of the drive units is required, which causes a great deal of effort. In addition, the belt loop required for length compensation is the reason for a not inconsiderable space requirement, quite apart from the mechanical expenditure for the dancer roller and the deflection rollers adjacent to it. Furthermore, the multiple belt deflection required as a result of the loop provided here has a negative effect on the life of the belts.

In another known arrangement (DE-AS 22 29 414) to form a switch, a piercing scoop is provided which is movably arranged above the scale track and which can be inserted with its tip between two successive products and which feeds the products accumulating on it to a downstream belt guide. In this known arrangement, too, a high acceleration of the lancing vane and the downstream belt guide is required in order to ensure a clean separation of the scale flow, which also means that high inertial forces, jerky operation and high wear can be expected. In addition, it can happen that the piercing scoop runs onto a folded product, so that the subsequent products have to slide over it, which can very easily lead to a jam. Apart from that, the drive and the storage of the grooving vane and the associated belt guide require a very high level of mechanical engineering.

In a further known arrangement (DE-AS 28 48 010), a belt section is provided with a relatively strong front belt roller, which is associated with a further short belt section arranged above the belt section and received on a swivel frame, which forms a switch around its lower one , on the strong front belt roll, the belt roll can be folded into an upward rearward position and can be brought into operative connection with a separating roll that can be inserted between two successive folding products. In the normal transport position, the aforementioned strong front belt roller and the associated short belt section limit an approximately S-shaped conveyor channel. This should result in a certain fanning out of the folded products pressed through the S-shaped conveying channel. However, it is disadvantageous that the S-shaped deflection of the conveyor section results in a relatively high stress on the products, which can lead to undesirable pinch folds and the like, or to smearing of the possibly still fresh pressure, in particular in the case of thick folded products and with a small scale spacing. This known arrangement is therefore not suitable for high machine speeds.

Proceeding from this, it is therefore the object of the present invention, while avoiding the disadvantages of the known arrangements, to provide a waste gate of the type mentioned which can cope with a comparatively high running speed of the conveyor belts and yet can be adjusted slowly and therefore largely smoothly, and which at the same time is simple in structure and works reliably.

This object is achieved according to the invention in that the position of the belt roll, which can be changed in position, can be pivoted downward around the axis of a stationary belt roll belonging to the same belt stretch and can be brought into engagement with an exposed pressure roll arranged above it in the region of its normal position aligned with the adjacent belt stretch and that the circumferential portion on the interspace side of the belt roller forming the interstice boundary in the transport direction is provided with a cover.

These measures advantageously result in a pivotable belt section which, in its position pivoted out of the normal position, simply conveys the folding products located thereon past the subsequent belt section into a special waste delivery. The band length advantageously remains in each pivot position the same, so that compensating devices can be omitted. The waste products to be sorted out are also not lifted off the belt section, but are simply thrown off via the front belt roller of the swiveling belt section. Movable separating elements such as plungers, separating shafts or the like are therefore not required here. When the swiveling belt section returns to the starting position, the pressure roller assigned to its front belt roll ensures that the folded products that have entered the gap between the two successive belt sections during the return movement are reliably transported further in this direction. At the same time, the interspace-side covering of the rear belt roller of the front belt section prevents these products to be sorted out from being taken along in the opposite direction of transport. The measures described above therefore ensure that a traffic jam is reliably avoided. As a result of these measures, the pivoting movement can advantageously be carried out relatively slowly, which not only ensures pressure-free operation but also enables the use of relatively simple drive units. The advantages that can be achieved with the invention can therefore be seen in particular in excellent economy.

Advantageously, the cover associated with the belt roller forming the front space delimitation in the direction of transport can be designed as a guide wedge tapering downward, which can expediently be curved in accordance with the contour of the adjacent belt roller. These measures advantageously result in a stationary separating element, which intervenes when the pivotable belt section returns to its starting position between two successive products, the upper, broad end face of the guide wedge forming a support over which the first product following the separating point safely connects the downstream belt section is fed. On the other hand, it is ensured that the specimens already guided on the long sides of the guide wedge are transported on without backlog.

According to a further advantageous embodiment of the superordinate measures, the lowerable belt roller can be accommodated on a swivel frame which can be swiveled as a whole by means of at least one actuating cylinder. These measures advantageously enable simple support of the tapes despite the fact that the tape guide can be pivoted.

Further advantageous refinements and expedient further developments of the superordinate measures result from the following description of an exemplary embodiment with reference to the drawing in conjunction with the remaining subclaims.

• Figur. 1 eine Seitenansicht der erfindungsgemässen Transportstrecke mit der bei geschlossener bzw. geöffneter Weiche sich ergebenden Schuppenbahn und
• Figur 2 eine Seitenansicht der erfindungsgemässen Transportstrecke mit der beim Schliessen der Weiche sich ergebenden Schuppenbahn.

The drawing shows:

• Figure. 1 shows a side view of the transport route according to the invention with the scale train and the resultant rail when the switch is closed or open
• FIG. 2 shows a side view of the transport route according to the invention with the scale track resulting when the switch is closed.

The transport route downstream of the paddle wheel of a folding apparatus and leading to a delivery station, for example a parcel delivery, is normally subdivided into several belt routes arranged one behind the other for reasons of practicality. The basic structure and arrangement of such a belt section is known and therefore requires no further explanation. FIGS. 1 and 2 show two strip sections 1 and 2 which are arranged at a distance from one another and which are linked to one another by means of a third, pivotable strip section 3. These belt sections 1, 2, 3 consist of narrow individual belts 4 which are arranged next to one another at a distance and are each placed on a front and a rear belt roller. The front belt roller 5 of the belt section 1 on the impeller wheel simultaneously forms the rear belt roller of the pivotable belt section 3, so that there is practically a seamless transition from the belt section 1 to the belt section 3. The front belt roll 6 of the pivotable belt section 3 is independent of the rear belt roll 7 of the downstream belt section 2 and is arranged at a distance therefrom, so that there is a small space 8 between these belt rolls 6 and 7. As long as the belt roller 6 is aligned with the adjacent belt roller 7, the space delimited by these belt rollers is however so small that the scale path generated by the paddle wheel, indicated at 9, can reach over it unhindered.

When processing web-shaped material in a rotary printing press, it is known to simply glue the webs pulled off from one after the other to be used to accomplish a so-called flying roll change. The products containing the glue line, which is marked in color on the sheets, are waste and must be removed from the scale sheet leading to the delivery. For this purpose, the swiveling belt section 3 is simply lowered with its front belt roller 6 from its normal position, which is aligned with the adjacent stationary belt sections 1 and 2 and is indicated by solid lines in the figures, in such a way that the scale track 9 in the area between the adjacent belt rollers 6 and 7 tears off and the products arriving behind this web separation are dropped into a separate delivery via the front belt roller 6 of the pivotable belt section 3. The lower pivot position of the pivotable belt section 3 is indicated in FIGS. 1 and 2 with dash-dotted lines. The products 10 thrown off via the front belt roller 6 arrive here with simply via a slide arranged below the belt roller 6 into a container for waste products not shown here.

The front belt roll 6 of the lowerable belt section 3 can be pivoted about the axis 12 of the associated rear belt roll, which is arranged stationary. For this purpose, a swivel frame 13 is provided which is swivel-mounted coaxially to the axis 12 and accommodates the front belt roll 6 and which can simultaneously serve as a support for the belts 4 of the belt section 3 which can be lowered. To actuate the swivel frame 13, an actuating cylinder 14 is provided which is supported on the one hand on the machine housing and on the other hand engages with its piston rod on the swivel frame. The actuating cylinder 14 can be a pneumatic cylinder, which is connected via a pressure line 16 controlled by a valve 15 to a compressed air source, not shown here. The valve 15 should in turn be actuable for activation or passivation of the actuating cylinder 14 by a control device which comprises a sensor 17 arranged above or below, here below the scale path 9, which responds to the color marking marking the adhesive point and a measurement transducer 18 connected thereto with its outlet 19 on valve 15. The sensor 17 can be designed, for example, as a photocell, the electrical output signal of which is amplified by the converter 18 to such an extent that the coil of the valve 15, which is expediently designed as an electromagnetic valve, can be excited with it. The actuating cylinder 14 can work at a very low speed in comparison to the belt speed, which has an advantageous effect on the resulting mass forces and the required drive energy. The sensor 17 of the control device is therefore expediently arranged in such a way that an early notification of the beginning or end of the waste occurs. Since the scale web 9 tears off faster when the belt section 3 is lowered than when the belt section 3 is pivoted back, a delay element, not shown here, can expediently be provided in the control device, which only passes on the signal waste beginning with a certain time delay. The upper and lower swivel positions of the swivel frame 12 are expediently defined by stops.

Above the front belt roller 6 of the swiveling belt section 3, a pressure roller 20 is provided, which comes into contact with the transported products in the normal position of the lowerable belt section 3, which is aligned with the two adjacent belt sections 1 and 2, and which presses against the front belt roller 6 of the lowerable products Belt section 3 presses, so that there is practically a positive feed in this area, which is particularly advantageous when returning the lowerable belt section 3 from the pivoted position to the normal position, as can best be seen from FIG. The products of the products in FIG. 2 that are still in motion during the relatively slow upward movement of the front belt roll 6 of the lowerable belt section 3, which is pivotably mounted about the stationary axis 12 of the rear belt roll, with its front edge into the space 8 between the adjacent belt sections 3 and 2 at 21 indicated type are reliably transported due to the positive drive effected by the pressure roller 20 and can not stand still, so that a jam is reliably prevented. The pressure roller 20 is freely exposed above the scale web 9 so that it is slightly raised when the front belt roller 6 of the pivotable belt section 3 comes up and thus presses the products to be transported with their weight onto the belts or the belt roller located underneath. To increase the contact pressure, a spring could additionally be provided, in which case a particularly light design of the contact roller is possible. In the exemplary embodiment shown, the pressure roller 20 is received with its lateral bearing pins 22 in guides 23 extending in the lifting or lowering direction, the lower end of which is delimited by a stop 24. In the present case, simply U-shaped brackets are used for this purpose, into which the bearing pins 22 are inserted. The guides 23 are arranged fixed to the machine, so that the lower position of the pressure roller 20 is defined. The machine frame, which also accommodates the stationary belt rollers and the lifting cylinder 14, is not shown here for the sake of clarity.

In order to prevent the products of the type indicated at 21 that shoot in or protrude into the gap 8 when the lowering movement is initiated or when the lifting movement of the lowerable belt section 3 ends, or protrudes into it, for engagement with that of the front belt roller 6 lowerable belt section 3 adjacent rear belt roll 7 of the belt section 2 arranged upstream in the transport direction and are acted upon by this against the desired transport direction, the intermediate peripheral section of this belt roll 7 is provided with a cover 25. In the exemplary embodiment shown, this cover is designed as a guide wedge tapering downwards, which can be bent in accordance with the contour of the associated belt roller 7, so that there is no significant space requirement. The upper end face of the guide wedge advantageously results in a wide contact surface 26, through which the front edge of the first product 27, which no longer enters into the space 8, is fed to the downstream belt section 2 and through which the trailing edges of the belt roller 6 are initiated when the lowering movement of the belt roller 6 is initiated products that have already reached the belt section 2 are supported with their front area. The cover 25 designed as a guide wedge thus advantageously forms at the same time a stationary separating element which, when the Lowerable belt section 3 engages with the edge formed by the upper run-up surface 26 and the side flank between two successive products and thereby separates the shingled stream reaching the waste paper tray 11 from the shingled stream to be transported away via the downstream belt section 3. The pressure roller 20 advantageously results in a certain fanning out of the products, so that the penetration of the guide wedge is facilitated, as can best be seen from FIG. 2.

Claims (7)

1. A switch for a transport path accommodating an overlapped stream of folded paper products, in particular downstream of a folding apparatus and leading to a support station, said transport path consisting of a plurality of successive conveyor belt flights (1,2,3) with conveyor belts (4) moving about belt rolls (5, 6, 7), at least the downstream belt roll (6) being movably supported between belt rolls (6, 7) demarcating two successive conveyor belt flights (3, 2) an being adapted to change their spacing relative to an adjacent conveyor belt flight (2) by means of an actuating element (14) adapted to be activated by a control means (15 to 19), characterized in that the belt roll (6) whose position can be changed is adapted to be pivoted downwardly about the axis of a stationary belt roll (5) belonging to the same conveyor belt flight (3) and brought into engagement with a free backer roll (20) located above it in the region of its normal position aligned with the adjacent conveyor belt flights (1, 2), and that the circumferential section of the belt roll (7) forming the front space delimitation in the direction of transport is provided with a cover (25).

2. The switch as set forth in claim 1, characterized in that the free backer roll (20) located above the lowerable belt roll (6) is accommodated in a guide (23) extending in the direction of lifting and lowering, the lower end of which is demarcated by a stop (24) relative to which said backer roll (20) is slightly raised in the normal transport position of the lowerable conveyor belt flight (3) aligned with the adjacent conveyor belt flights (1, 2).

3. The switch as set forth in claim 2, characterized in that said guide (23) consists of U-shaped loops taking up the bearing pins (22) of said backer roll (20).

4. The switch as set forth in at least one of preceding claims 1 to 3, characterized in that the cover (25) associated with the belt roll (7) forming the front space delimitation in the transport direction is designed as a downwardly tapered wedge.

5. The switch as set forth in claim 4, characterized in that the cover (25) designed as a wedge is bent to conform to the contour of the associated belt roll (7).

6. The switch as set forth in at least one of preceding claims 1 to 5, characterized in that the lowerable belt roll (6) is mounted on a rocking frame (13) which can be rocked by means of at least one driving cylinder (14).

7. The switch as set forth in at least one of preceding claims 1 to 6, characterized in that stationary belt roll (5) ot the lowerable conveyor belt flight (3), about the axis (12) of which the rocking frame (13) is pivotally mounted, accommodates the conveyor belts (4) of the successive conveyor belt flights (1, 3).

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