GB2079802A - Web folding device - Google Patents

Abstract

Laundered sheets and other articles in the form of a web are folded by being fed downwardly, having the leading end portion clamped between fixed and movable abutments 3, 4 so that the web descending past the held portion forms a descending fold 7, and receiving the descending fold on a conveyor 2. The web may be given an initial fold 6 or 6a which forms the portion held between the abutments 3, 4, so that the conveyor receives a twice-folded web. Pivotable stacking fingers 10, Fig. 5, may be swung to transfer the folded web 5a onto a stacking table 11. <IMAGE>

Description

SPECIFICATION Web folding device This invention relates to devices for folding webs of flexible material. It is particularly applicable to laundry folding devices and in particular devices for folding laundry flat work articles such as sheets, table linen, etc.

It is customary when processing a sheet to iron it in a rotary ironing machine and pass it on a conveyor through a folder which makes one or more folds about lines transverse to the direction of travel of the sheet and then to pass the sheet to a cross folder which makes one or more folds tranverse to the former folds.

Folding devices used at present operate in one of two ways. In the first way the predetermined centre of the sheet is deflected between contra-rotating rollers. The second way is to raise the leading edge of the sheet from a conveyor and to hold it in this position while the remainder passes beneath. The leading edge is then released on top of the trailing edge.

Each of these methods has disadvantages when making the second cross fold on multilane cross folders.

The first cross fold is made by passing the centre of the sheet downwards between contra-rotating rollers and allowing it to drape onto a lower conveyor. As the sheet passes along the lower conveyor it receives its second cross fold usually by one of the previously described methods.

On multi-lane cross folders there are several sets of contra-rotating rollers positioned across the width of the machine. On set for oach lane.

In order that the operation of the second cross fold for one lane does not interfere with that of another lane it is necessary, using existing folding devices, to have either parallel lower conveyors for each lane or an extra wide conveyor to allow the lanes to be staggered.

According to the present invention, a web of material is folded by feeding the web downwards, holding a leading portion of the web while feeding the web downwards past the held portion, whereby the downwardly fed web forms a descending fold, and then releasing the held portion of the web when the desired length of fold has been formed.

A preferred procedure, comprises feeding the web downwards, moving a holding member laterally relative to the downward path of the web to hold a portion of the web to one side of its downward path, whereby the downwardly fed web will drape over the holding member and form a descending fold, moving the thus folded web, perpendicular to its width, below the holding member, and thereafter releasing the web from the holding member.

The holding membe may be a movable roller which clamps the web against a further member.

Preferably the web descends onto a moving surface below the holding member to effect the said perpendicular movement of the web.

The web is preferably fed downwards initially with a first fold, e.g. between contrarotating rollers, so that the operation of the holding member and the subsequent perpendicular movement of the web will form a second fold.

The present invention can eliminate the above mentioned difficulties in laundry folding devices. In the case of a multi-lane folder, a common conveyor can be used for the second fold, without interference between adjacent lanes.

Devices for forming a second fold in accordance with the present invention have additional advantages over the above mentioned method of raising the leading edge of the web from a conveyor and clamping it, in that the accuracy of the fold is affected less by the thickness and weight of the sheets or other articles being folded. Unlike devices which determine the centre of the sheet before folding, it does not require a complex measuring system.

The invention is illustrated by the accompanying drawings in which the Figs. 1 to 4 show successive stages in the formation of a twice-folded sheet, and Figs. 4 to 7 show successive stages in a further folding procedure.

Figures 1 to 4 show a pair of contrarotating rollers 1, mounted above a lower conveyor belt 2. A fixed horizontal bar 3 is mounted below the rollers 1, on that side of the nip towards which the conveyor 2 moves.

Parallel to the bar is a movable and freely rotatable roller 4, which can be moved towards and away from the bar for example by pneumatic cylinders or solenoids.

In operation, a sheet 5 is fed to the rollers 1 so that its central region descends between these rollers to form a first cross fold 6 as shown in Fig. 1. This first cross fold is fed downwards between the fixed bar 3 and the movable roller 4 which is in the initial position shown in Fig. 1.

When a predetermined length of the sheet has passed between the bar and the movable roller, the latter is moved across the path cf the sheet and clamps the leading edge of the folded sheet against the bar, as shown in Fig.

2. In this position, the roller 4 is clear of the descending remainder of the sheet, which therefore drapes over the roller and onto the lower conveyor 2, thereby forming a second fold on the moving conveyor as shown at 7 in Fig. 2.

As the trailing edges of the sheet pass from between the rollers 1, the movable roller 4 is returned ta its original position as shown in Fig. 3, thereby releasing the original leading edge 6 and moving it under the descending trailing edges of the sheet, so that the first fold and the trailing edges are transferred to the lower conveyor. The first fold is released easily and smoothly because of the free rotatability of the roller 4.

In the embodiment shown in the drawing, the holding roller is moved across the downward path of the web in order to move part of the web to one side and to hold it. In a possible alternative arrangement, the descending web may be gripped by holding means substantially on its descending path, and then moved to one side to allow the following descending portion of the web to form a fold.

The invention has been described with reference to the formation of a second fold, but is also applicable to the formation of a first fold, or indeed a third-or later fold.

Any suitable form of detection and control apparatus can be used for determining the position of the sheet or other article to be folded and performing the described operations in the correct sequence.

Figures 4 to 7 illustrate a slightly modified folding procedure, which can be used to form a single fold or, preferably, to collect a sheet folded by the previously described cross-folder, form a further cross-fold, and stack the folded pieces on a table or conveyor in convenient batches for subsequent handling or packaging.

The web 5a, in particular a previously folded web formed as shown in Fig. 3, is fed up the ascending limb of a triangular conveyor and over an extension conveyor 9 so that the leading end of the web can descend freely. Below the end of the extension conveyor 9 are a fixed abutment 3 and a movable roller 4 arranged in a manner similar to that shown in Figs. 1 to 3, and the conveyor 8 has a descending inclined portion below the roller 4. As the leading end of the web descends between the movable roller and the fixed abutment, the roller clamps it against the abutment as already described and the following part of the web forms a descending fold 6a on the inclined descending part of the conveyor. Pivotable stacking fingers 10 are mounted adjacent to the descending part of the conveyor, which carries the folded web into an excellent position for collection by the stacking fingers and transfer by pivoting of these fingers, as shown in Fig. 7, on to a stack table or conveyor 11.

It will be seen that a folding machine generally as shown in Figs. 4 to 7 could also be used for folding an unfolded web, or a singlefolded web supplied to it. It is suitable for folding hand-fed pieces, for example blankets, turkish towels and so on which are not, when laundered, passed through an ironing machine.

Claims (10)

1. A method of folding a web of material, comprising feeding the web downwards, holding a leading portion of the web while feeding the web downwards past the held portion, whereby the downwardly fed web forms a descending fold, and releasing the held portion of the web.

2. A method of folding a web of material - comprising feeding an intermediate region of, the web downwards to form a descending first fold, holding a leading portion of the first fold; while feeding the web downwards past the held portion whereby the web forms a second fold descending from the held portion, and releasing the held portion.

3. A method as claimed in claim 2 in which the second fold is moved perpendicular to the width of the web below the held portion.

4. A method as claimed in claim 2 or 3 in which a leading fold portion of the twicefolded web is held and the remainder of the twice-folded web is fed downwards past the held portion thereby forming a descending third fold, whereafter the held portion is released.

5. A method as claimed in any preceding claim in which the fold descending from the held portion is fed downwards onto a web conveyor which conveys the folded web under the held portion.

6. Web-folding apparatus comprising conveying means arranged to feed a web downwards, web-holding means comprising two relatively movable holding elements having a first position in which the holding elements are spaced apart on opposite sides of the downward web path and a second position in which the holding elements are moved together to hold between them a leading end portion of the downwardly fed web whereby the web will form a fold descending from the held portion, and means for receiving the descending fold.

7. Apparatus as claimed in claim 6 in which the receiving means is a conveyor movable transversely to the width of the web and arranged to convey the descending fold under the held portion.

8. Apparatus as claimed in claim 6 or 7 in which the web-conveying means comprises means for forming an initial descending fold in an intermediate portion of the web conveyed thereby.

9. Apparatus as claimed in claim 8 in which the means for forming the initial descending fold are centra-rotating rollers with a- gap therebetween for receiving the said intermediate portion of the web.

10. Web-folding apparatus substanially as herein described with reference to Figs. 1 to 4 or Figs. 5 to 8 of the accompanying drawings.