EP0429743B1 - Sheet delivering device - Google Patents

Abstract

A sheet deliverer apparatus for a sheet processing machine, particularly a sheet printing machine with a high stapling or stacking sheet delivery capability, wherein sheet deliverer upper and lower chain guide ways extend in the same direction of curvature, and a clamping device is provided to clamp the sheet deliverer chains in tension to provide very even and silent running of the sheet deliverer chains and the gripping pads, extended service life and uniform sheet travel free of flutter over the complete conveying way to the delivery staple or table or permit increased conveying output.

Description

The invention relates to a sheet delivery of a sheet-processing machine, in particular a sheet-fed printing machine with a stacking tray, preferably with a stacking tray, in which the sheets are removed from a cylinder of the machine with the aid of controlled gripper fields and conveyed to a stacking table, on which they are deposited and are stacked into a stack, the mutually parallel and spaced gripper fields being fastened at their ends on both sides to circumferential chains which run in chain guides with upper and lower guide flanks, the chains being guided on deflection guides on the input and output sides of the sheet delivery and the chains together their chain guides describe guideways that run from the input-side deflecting guide upwards over the stacking table and the upper and lower chain guideways have curves between the respective transfer points on their deflecting guides write.

Arch supports with these known features have become known in numerous embodiments. They have in common that the chain guide track is Z-shaped in a side view, ie with changes in direction, or there is at least one straight section on the upper and lower chain guide tracks. As an example, reference is made to the sheet delivery according to DE-PS 23 08 025 or FR-A-1 041 321. However, this roughly speaking Z-shaped course of the chain guide track or its partially straight extension has the disadvantage that the roles of the chain links change with each change of direction of the chain guide track with strong noise from the system on one side, for example the lower chain guide flank, to the other, for example on the upper chain guide flank, or vice versa. This effect is based on the one hand on the inertia of the moving masses when the direction changes and these centrifugal forces are even greater at the points, to which the gripper fields are attached to the chains, which have a tangible mass, and on the other hand by changing contact flanks within the closed chain guides in the direction change areas as a result of the tension and tensile forces of the chains.

After a certain operating time, this so-called beating and the flank change of the chain links within the guides lead to damage to the rollers and in particular to the chain guides, combined with a noticeably increasing noise level. This, in turn, places limits on the speed of the boom in the case of sheet booms according to the prior art, in order to keep the disadvantages described within limits. Future sheet delivery should, however, convey (lay out) at higher speeds than conventional sheet delivery. Another disadvantage is that the mentioned changes in direction of the chains in the Z-shaped chain guide tracks lead to a wave-like, flag-fluttering movement of the sheets transported by the gripper fields, which is also disadvantageous and performance-inhibiting in sheet conveying and perfect stacking, especially when printed on both sides are, because it can also lead to undesirable smearing of the still fresh printing inks on the sheet guides.

Another sheet delivery with the features mentioned above also describes the German patent specification 25 44 566, in which several changes in direction for the direction of movement of the chains are provided in the lower and upper chain guide track, which lead to the problems described. This document also describes a sheet guide plate, which is provided there at a short distance below the lower chain guide track and parallel to it and that extends approximately to the front edge of the stacking table. In operation, this sheet guide plate forms an air cushion between itself and the sheets conveyed above it, which uniformizes the transport of the sheets without the sheets touching the guide plate.

Regarding the prior art, reference is also made to DE-PS 852 545, which describes a device for holding the fold-up chain boom frame of a sheet-fed printing machine. The drawing of this publication may possibly show a guide path of the chain guides, which is not mentioned there in the text, but which has short sections with a constant, upwardly curved sense of curvature. However, these sections only extend to about a third of the total chain guideways in order to compensate for a small difference in height and then change the direction to a straight horizontal, which also results in a change of direction there in a straight line, and the constraint of the chain rollers on a and the same leading edge is not possible despite chain tension and tensile forces. In addition, a flat stack tray is apparently used there, so that the sheets only have to be conveyed upwards by a relatively small amount, which noticeably reduces the problems described. In general, it should be mentioned with regard to this publication that above an interpretation of contours of the chain jib structure indicated there only with lines represents it, without this interpretation being supported in the description there. The illustrated drawing can therefore only relate to the frame of the sheet delivery, and not, for example, the chain guide, so that this document has no significant significance in relation to the present invention.

Starting from a sheet delivery of the type mentioned, the object of the invention is to design it in such a way that the service life of the chain links and components, and in particular the chain guides that work with them, is appreciably increased, and the noise level should also be noticeably reduced during operation, in particular after a longer operating time, and higher operating speeds should be possible. The sheets should also be able to be conveyed from the cylinder (pressure cylinder) of the previous machine to the stacking table as evenly and without fluttering, which is the most important prerequisite for higher conveying capacity per unit of time.

To achieve this object, the invention is characterized in that the curves each have a constant sense of curvature over their entire course and in that a tensioning device is provided which presses all chain links with their rollers over the entire guideways onto one and the same guide flank of the chain guideway in question.

The chain guideways described are thus guided over the entire route without changes in direction, thereby avoiding the disadvantages described. This ensures that the rollers of the chains run with one-sided play between the flanks of their upper and lower chain guide. The upper chain guide flanks thus only serve to prevent the chains and gripper fields from flying out in the event of external interference.

Because of the described profiling of the chain guideways and the tension of the chains, the chain rollers are always in contact with only one, namely the lower guide flank of the chain guide, and their direction of rotation remains the same over the entire course of the lower and over the entire course of the upper chain guideway. A change in the direction of rotation of the chain rollers, as occurred in the prior art in the direction change described, no longer exists and also the disadvantages associated therewith, in particular there is no more tearing off of the lubricating film between the rollers and the flanks of the chain guides, as a result of which the damage described in the prior art was also caused. Also, there is no longer any striking of the chains between the guide flanks, due to the transition of the chain rollers from the lower flank of the chain guide to the upper flank or vice versa, and there is therefore no more damage, even if they are with a large one Mass provided gripper fields are taken into account. The associated noise developments are also avoided, so that overall a higher working speed is possible.

It is preferred if a sheet guide plate is provided at a short distance below the lower chain guide track and parallel to it, which extends approximately to the front edge of the stacking table. These measures are known per se from the already mentioned DE-PS 25 44 566, but not together with the characterizing features of patent claim 1. These measures form an air cushion between the sheet guide plate and the sheets conveyed close above it, thereby causing a disadvantageous effect Fluttering of the sheets and smearing of the still fresh ink on the reverse side during transport is avoided.

Fig. 1 -

schematisch und in einer Seitenansicht die wesentlichen Bauelemente eines erfindungsgemäßen Bogenauslegers;

Fig. 2 -

in einer demgegenüber vergrößerten Darstellung die Einzelheit Z von Fig. 1;

Fig. 3 -

in abermals vergrößertem Maßstab einen Schnitt längs der Linie III-III von Fig. 1.

The invention is explained in more detail below on the basis of an exemplary embodiment from which further important features result. It shows:

Fig. 1 -

schematically and in a side view the essential components of a sheet boom according to the invention;

Fig. 2 -

in an enlarged representation the detail Z of FIG. 1;

Fig. 3 -

on a further enlarged scale a section along the line III-III of Fig. 1st

It should be mentioned that the invention is described in the following using the example of a sheet-fed printing machine with a high-stacker. However, it is generally applicable to sheet-processing machines, which preferably have a high-stacker, because here the problems that occur in the prior art and described above are most serious. Possibly. However, the invention can also be used successfully in sheet-processing machines of this type with flat stacking.

In FIG. 1, sheets printed on one side or possibly also on both sides are removed from a printing cylinder 1 which rotates in the direction of arrow 2 and transferred to a front deflection guide of a sheet delivery. In the exemplary embodiment shown, the front deflection guide is formed by a deflection sprocket pair 3. However, other deflection guides are also known and possible. The chain wheels of the chain wheel pair 3 rotate in the direction of arrow 4.

Chains 5 are placed over the front sprocket pair 3 and over a corresponding rear sprocket pair 6, which forms the rear deflection guide for the chains in the exemplary embodiment shown. At a distance from one another, several gripper fields 7 are fastened to the chains. Such a gripper field is explained in more detail below with reference to FIG. 2. With the controlled gripper fields, the sheets are removed from the printing cylinder 1 and released via a stacking table 9, so that they are deposited on the deposit table and form a sheet stack 10.

As shown in FIG. 2, the chain 5 consists of link plates 11 of normal pitch, rollers 12, sleeves 13 located therein and chain pins 14 located inside of them again are long.

The gripper field has gripper supports 16, a plurality of grippers 17 and a torsion spring 18 closing the grippers 17 across the format width of the sheet delivery.

The grippers 17 are actuated at the point where a sheet is to be removed from the machine and at the point where the sheet is to be deposited over the deposit table 9, by means of a lever 20 of a roller 21, which in turn is supported by a fixed, in many cases, however, an adjustable gripper opening curve is actuated.

In Fig. 1 are also a front transfer point 22 between the front pair of sprockets 3 and the upper run of the Chains 5 are shown and a rear transfer point 23 between the rear sprocket pair 6 and also the upper run of the revolving chains 5. In addition, a further transfer point 24 is drawn in FIG. 1 between the front sprocket pair 3 and the lower run of the revolving chains 5 and a rear one Transfer point 25 between the rear pair of chain wheels 6 and the lower run of the circulating chains 5.

The complete curves of the chain guideways between the transfer points 22, 23 of the upper run and the transfer points 24, 25 of the lower run run continuously in the same direction, i.e. in the view of Fig. 1 arched substantially upwards.

In Fig. 1 it is also indicated that a tensioning device 28 is provided which always keeps the chains under tension. In the embodiment shown here, a compression spring 29 is provided, which tries to press the rear sprocket pairs 6 in the direction of arrow 30 and thereby tensions the chains so that the rollers of all chain links in the entire area of the described chain guideways of the upper and lower run to the same, namely the lower guide flank 35 of the chain guides are pressed. This ensures that the direction of rotation of the rollers does not change. This results in a particularly soft and gentle running of the chains together with their gripper fields, which have a tangible mass. The spring 29 works against a fixed abutment 31.

In addition, a sheet guide plate 32 is indicated in FIG. 1, which extends below the front pair of sprockets and approximately to the stack 10.

The guidance of the chains 5 in the curves described is achieved by chain guides 33, the construction of which can be seen in detail in FIG. 3. These chain guides are C-profiles, which thereby form an upper chain guide flank 34 and a lower chain guide flank 35. The chains run with their chain rollers 12 in the openings of these C profiles with always one-sided play on the upper guide flank 34.

According to the invention, the upper chain guideway between the transfer points 22, 23 and the lower chain guideway between the transfer points 24, 25 describe curves which have a constant sense of curvature over their entire course.

The advantages achieved with this were explained in the introduction to the description. The sheet guide plate 32 smoothes out the transport of these sheets by means of the air cushion between them and the conveyed sheets, without these fluttering.

Claims (2)

1. Sheet delivery of a sheet treating machine, particularly a sheet printing press with a pile deposit, preferably with a high pile deposit, in which the sheets are taken off with the aid of controlled gripper pads (7) from a cylinder (1) of the machine and fed to a pile table (9) on which they are deposited end piled to form a pile (10), wherein the gripper pads parallel to one another and at distance from one another are fixed at their ends on both sides of circulating chains (5) which run in chain guides (33) with upper and lower guide flanks (34, 35), wherein the chains (5) are guided on the input side and on the output side of the sheet delivery via turnround guides (3, 6) and the chains (5) together with their chain guides (33) describe guide paths which run from the input side turnround guide (3) upwardly over the pile table (9) and wherein the upper and the lower chain guide path describe curves between the respective transition points (22, 23, 24, 25) at their turnround guides (3, 6), characterised in that the curves in each case have a sense of curvature remaining the same over their entire run and that a tensioning device (28) is provided which presses all chain members with their rollers (12) over the whole guide paths on one and the same guide flank (34, 35) of the respective chain guide path.
2. Sheet delivery according to claim 1 characterised in that a sheet guide plate (32) is provided at a small distance below the lower chain guide path and parallel to it which extends substantially up to the front edge of the pile table (9).

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