GB2099797A

GB2099797A - Sheet feed means

Info

Publication number: GB2099797A
Application number: GB8216180A
Authority: GB
Original assignee: Polygraph Leipzig Kombinat Veb
Current assignee: Polygraph Leipzig Kombinat Veb
Priority date: 1981-06-04
Filing date: 1982-06-03
Publication date: 1982-12-15
Also published as: JPS57203636A; DD159419A1; JPS6351938B2; IT1156471B; IT8267711A0; DE3212971A1; GB2099797B

Abstract

A sheet feed table for the conveying and lateral aligning of paper sheets, comprises pressure-exerting means, such as balls 3, and rectilinear aligning means, e.g. reference edge 11, disposed laterally of a sheet conveying path. In the vicinity of the aligning means and beneath the pressure-exerting means, an upper belt 2 is arranged to be adjustable in distance from the plane of the conveying path and to continuously run in the direction of the sheet conveying, the belt 2 being loaded by the balls 3 which are held above the sheet feed path in a guide 16. <IMAGE>

Description

SPECIFICATION Sheet feed means The present invention relates to sheet feed means, and has particular reference to a table for the conveying and lateral aligning of sheets of paper for a sheet aligning station in a bookbinding machine.

Apparatus for this purpose have been disclosed in various forms, which depending on the type of paper to be processed and the number of folds, exhibit various disadvantages which in practice restrict their functional capability. Probiems are especially present in the conveying of bulky or thick folded sheets. Due to ball "springing" of pressure-exerting balls caused by upstanding edges of the sheets, nonuniform sheet spacing with irregular sheet running occurs. The result is inaccurate guidance of the sheets along an alignment straight-edge, which leads to folding inaccuracies.The sheet loading or pressureexerting means disposed above the sheets to be conveyed are in general adapted in their mass to the type of paper to be processed, as described in, for example, DE-PS 1103 356, and must act as closely as possible to the alignment straight-edge in order to prevent buckling up of the sheet. In processing of extremely thick or bulky folding sheets with folded edges at the alignment straight-edge, the necessary increase in the mass of the sheet loading means in order to prevent "ball springing" produces a high and disadvantageous sheet loading. Limiting members, which could prevent such springing have not proved successful, as they have a braking effect on the free run of the sheet loading means.

There is accordingly a need for sheet feed means with improved functional reliability in the processing of thick and bulky folded sheets, so that it can be used at sheet aligning stations under varying conditions imposed by the types of paper to be processed and the number of the folds. Such sheet feeds should desirably avoid interruption to the pressure loading of conveyed sheets.

According to the present invention there is provided sheet feed means comprising pressure means arranged along a sheet conveying path to exert pressure from above on sheets conveyed along the path, aligning means to laterally align the conveyed sheets, and a circulatable guide belt disposed laterally of the aligning means to guide sheets along at least a section of the path, the belt comprising a guide run which is arranged to be adjustable in spacing from the plane of the conveying path and to be subjected to pressure exerted by the pressure means.

In a preferred embodiment, laterally of an alignment straight-edge beneath the pressureexerting means there is provided, for the purpose of achieving uniform sheet conveying, accurate sheet guidance, and a steady sheet run, an upper band disposed adjustably at a distance from the plane of the sheet path and continuously moving in the direction of the sheet run, the band being loaded by sheet loading means held above the sheets in guides. The distance of the band from the plane of sheet path can be adjusted according to the thickness of paper or thickness of the folded sheets to be processed. The sheet loading means bearing on the upper face of the band which conveys the folded sheet are for preference vertically freely movable in their guide, so that adjustment of the guide is necessary only to the extent to which a free movement of the band would be impeded by it.The adjustable upper band can be combined either with a conveying and aligning table having an obliquely running band as conveying means or with a conveying and aligning table having a plurality of obliquely running, driven rolls. This makes possible use of the sheet feed means at sheet aligning stations in machines where conveying and alignment requirements continually vary according to the type of paper to be processed, such as in automatic filament sealing machines. The conveying and aligning of sheets of different thickness, whether produced by single or multiple folding, has previously not been achieved with a single sheet feed means.

Expediently, a conveying and aligning table having an obliquely running band as conveying means is combined with the adjustable upper band and the latter is disposed to be used as desired. For further improving the guidance of the sheets, there can be included in this conveying and aligning table a holding-down device which is adjustable in its distance from the plane of sheet path and which is arranged to bear closely against the alignment straight-edge.

A further possible use of sheet feed means embodying this invention is in the context of a corner conveying table for folding machines, in particular in the feed zone for the folding mechanisms, that is outside the corner conveying region for the maximum format.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a schematic elevation of sheet feed means according to a first embodiment of the invention; Fig. 2 is a sectional view of part of sheet feed means according to a second embodiment of the invention; Fig. 3 is a plan view of the sheet feed means of Fig. 2, with an upper band thereof omitted; and Fig. 4 is a schematic elevation of upper and lower bands of the sheet feed means of Fig. 2.

Referring now to the drawings, there is shown in Fig. 1 sheet feed means in conjuction with a corner or angled conveying table for a sheet folding machine. At this position problems arise especially in the conveying of thick or bulky folded sheets to the last folding mechanisms. Through guidance of the folded sheet 1 by means of a continuously running upper band 2, which is uniformly loaded by balls 3 held in guide 16, ball "springing" associated with irregular sheet spacings and irregular sheet running can be avoided. The upper band 2 is guided outside the corner conveying zone for the maximum format by a driven belt roller 4, a deflection roller 5 and a tensioning roller 6. In this region there takes place simultaneously an aligning of the folded sheet 1 against a corner conveying straight-edge 7 before feeding into a folding mechanism 8.The conveying of the folded sheet 1 takes place, in the case of this conveying and aligning table, by a plurality of obliquely running, driven corner conveying rolls 9.

The conveying and aligning table according to Figs. 2 to 4 is disposed between a folding mechanism and the sealing station of an automatic filament sealing machine. The folded sheet 1 is conveyed by an obliquely running lower band 10 in the direction of the arrow and simultaneously laterally against an aligning straight-edge 11. In the processing of bulky or thick folded sheets, these are guided along the aligning straight-edge 11 by means of the continuously running upper band 2. The band 2 is uniformly loaded by the balls 3 held in the guide 1 6, without the forward edges of the folded sheet 1 being able to penetrate into the spacings between two balls 3, which would cause these balls to be thrown upwards and lead to inaccurate bearing of the sheet against the straight-edge 11.

The roller 4 driving the upper band 2 and also the deflection roller 5 and tensioning roller 6 are vertically adjustably mounted, for example on eccentric pins, to enable adaptation to the thickness of the sheet. In the processing of folded sheets of thin paper and with few folds, guidance by the balls 3 may be sufficient. For this operating case, the band 2 can be either brought out of engagement or removed from the rollers.

For further improvement in the guidance of folded sheets, a sheet-holding-down device 12 adjustable in distance from the plane of sheet run can be provided. The thickness setting corresponding to the sheets 1 to be processed can be carried out by means of adjustment screw 13 in such a manner that the device 12 fixed to a holder slides on a guide surface 14, which has the same angle of inclination as the bearing surface of the straight-edge 11. As a consequence, in every position of the device 12, a tight bearing against the straight-edge 11 is achieved and thin folded sheets 1 are prevented from jamming between the two components. At the conveying and aligning-table, an adjustment device 1 7 is provided for adjusting to the different format widths, i.e. the conveying and aligning unit is disposed to be movable transversely to the conveying direction. A conveyor belt 1 5 may be used when required for supporting the folded sheets 1 against the side opposite to the straightedge 11.

In the case of the described embodiments, the problems which arise at the sheet alignment station of a machine having continually changing requirements with respect to the conveying and aligning device can be solved by a single conveying and aligning table.

Claims

1. Sheet feed means comprising pressure means arranged along a sheet conveying path to exert pressure from above on sheets conveyed along the path, aligning means to laterally align the conveyed sheets, and a circulatable guide belt disposed laterally of the aligning means to guide sheet along at least a section of the path, the belt comprising a guide run which is arranged to be adjustable in spacing from the plane of the conveying path and to be subjected to pressure exerted by the pressure means.

2. Sheet feed means as claimed in claim 1, comprising an obliquely arranged conveyor belt for conveying sheets along the conveying path, the guide belt being movable out of its operative position.

3. Sheet feed means as claimed in either claim 1 or claim 2, comprising a device which is arranged to bear against the aligning means to hold down the conveyed sheets and which is disposed to be adjustable in spacing from the plane of the conveying path.

4. Sheet feed means substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

5. Sheet feed means substantially as hereinbefore described with reference to Figs. 2 to 4 of the accompanying drawings.