GB2135978A

GB2135978A - Belt loader for signatures, sheets, magazines and similar articles, for loading the feeders of packaging machines, binding machines and the like

Info

Publication number: GB2135978A
Application number: GB08402908A
Authority: GB
Inventors: Aris Ballestrazzi; Lamberto Tassi
Original assignee: SITMA Societa Italiana Macchine Automatiche SpA
Current assignee: SITMA Societa Italiana Macchine Automatiche SpA
Priority date: 1983-02-18
Filing date: 1984-02-03
Publication date: 1984-09-12
Also published as: DE3403314A1; SE8400844D0; SE8400844L; IT8320854V0; GB8402908D0; FR2541254A1; NL8400487A

Abstract

This invention relates to a belt loader for signatures, sheets, magazines and similar articles, for loading the feeders of packaging machines, binding machines and the like, which comprises a first conveying belt 16 driven via an adjustable speed variator 40, followed by a second transfer belt 21 having a linear speed of advancement which is greater than that of the first conveying belt and comprising an initial rising portion 19 and then a level portion 20, followed by a pair of expulsion rollers 31, 32. <IMAGE>

Description

SPECIFICATION Belt loader for signatures, sheets, magazines and similar articles, for loading the feeders of packaging machines, binding machines and the like This invention relates to a belt loader for signatures, sheets, magazines and similar articles, for loading the feeders of packaging machines, binding machines and the like.

Packaging, inserting, collating, folding, stapling and sewing machines and the like normally receive the articles to be processed by way of a so-called collection line, on which these articles are often formed by building them up from a plurality of individual elementary articles. Thus for example, a magazine is generally formed from a plurality of so-called signatures, ie large printed sheets folded a number of times (two folds for eight pages, three folds for sixteen pages etc.).

In this case, the collection line which feeds the binding machine is itself fed by a number of individual feeders equal to the number of signatures which are to make up the magazine.

Each of these feeders is provided with its own store, also known as a box, from which suitable members withdraw the relative individual article one at a time, ie a determined signature in the case under consideration, in order to transfer it on to the collection line. It is apparent that the box of this feeder must be regularly loaded with articles in order to ensure their continual availability and to avoid machine stoppages.

The periodicai loading of the boxes of said feeders, which have a limited capacity, requires much labour if effected manually, and this work is also fairly fatiguing in that the feeders are generally located at a considerable height from the floor. A further disadvantage of this manual system for loading the feeder boxes is the fact of not having a constant pile of individual articles in the boxes, so that the members for withdrawing and transferring the individual articles do not operate under constant conditions, and this can give rise to difficulties in the withdrawal of the articles from the box.

To obviate these drawbacks, belt loaders have already been proposed for loading the said feeder boxes.

These belt loaders comprise a first level conveying belt on which the articles are disposed standing up by an operator, followed by a second transfer belt having an initial upwardly inclined part and a second level part, the articles being distributed on the second belt in so-called scale formation, ie with partial mutual overlap. At the end of the level portion of the second transfer belt there is provided a pair of rollers which insert the articles into the box of the feeder served by the loading belt. This box is normally formed from a partly openable base and containing guides which vibrate in order to ensure exact positioning of the individual articles in a pile.

The second transfer belt of these known loaders is driven at a fixed linear speed which is greater than that of the first belt, in order to enable the articles to become distributed in scale formation on it. The ratio of the two speeds is constant and invariable.

These belt loaders are designed for feeding only signatures. As stated, these signatures are constituted by large sheets folded several times, and thus have good intrinsic rigidity in both directions because of their uniform thickness and their consistency on the folded sides. Because of these characteristics, no special difficulties are encountered in withdrawing said signatures and retaining them during their upward movement by the second transfer belt of the loader, and an automatic distribution in scale formation is also obtained on this belt with constant partial overlap of the individual signatures.

The object of the present invention is to enable a belt loader of the aforesaid type to be used not only for signatures, but also for other articles, such as individual sheets, magazines, envelopes etc., i.e. for articles having different thicknesses and thus of different rigidity and intrinsic consistency.

In this respect, in the case of thin articles such as single sheets of low rigidity and consistency, serious problems are created with regard to their regular withdrawal and their upward transfer, and it is also apparent that the degree of scale formation, i.e. the extent of their mutual overlap, varies as the article thickness varies.

If the two belts of the loader, i.e. the level conveying belt and the initialiy upward and then level transfer belt, move with a constant speed ratio, a more open degree of scale formation (less mutual overlap) is obtained with articles of greater thickness, whereas a more closed scale formation (greater mutual overlap) is obtained with thinner articles. This circumstance can lead to irregularities in the loading of the feeder box, and disturbances to the regular operation of this latter.

The present invention obviates these difficulties and drawbacks, and to this end proposes to motorise the level conveying belt of the loader by means of an adjustable speed variator which enables the linear speed of this belt to be varied in accordance with the thickness of the article being handled.

By means of this simple means which enables the ratio of the linear speed of the conveyor belt to the linear speed of the transfer belt of the belt loader to be varied, it has been found possible to use this loader for a plurality of articles, i.e. not only for signatures but also for individual sheets, magazines, finished catalogues, envelopes etc., while in all cases ensuring reliable transfer from the level conveying belt to the box or store of a feeder disposed at a higher level.

The relatively high linear speed of the loader transfer belt can remain invaried, whereas the linear speed of its level conveying belt must be relatively large in the case of articles of relatively large thickness, but must be reduced for relatively thin articles.

By adjusting the linear speed of the conveying belt in this manner, it has been found possible to obtain perfect transfer of the articles, independently of their thickness, from the level of the conveying belt to the higher level of the feeder box, while in all cases obtaining a constant degree of scale formation for the articles, i.e. the same extent of mutual partial overlap.

In order to further improve this article transfer, the invention also provides for varying the angle between the level conveying belt and the rising part of the transfer belt. Specifically, the invention provides for inclining the position of the conveying belt to the horizontal in both directions, while leaving the position of the transfer belt unvaried. This inclination of the conveying belt can be in one direction or the other, ie from its position in a horizontal plane the conveying belt can be moved into a position such that the articles are conveyed either upwards or downwards towards the transfer belt. In this manner, it is possible to vary the friction for the upward withdrawal of the articles in the initial portion of the transfer belt.In this respect, the facility for upwardly withdrawing and retaining the articles by the initial rising portion of the transfer belt is obtained essentially by the fact that in the set of articles disposed standing-up on the first level conveying belt, there is greater pressure in the lower part of the articles than in their upper part because of the drag force of the conveying belt on this set of articles.

Now in the case of thin articles of low strength, such as individual sheets, it has proved advisable to incline the conveying belt in such a direction as to obtain upward conveying towards the transfer belt, whereas in the case of articles of greater thickness, and particularly so in the case of magazines which in the folding zone of the individual sheets are puffed outwards and there is the danger of them falling backwards from their standing-up arrangement, the conveying belt is suitably inclined in such a direction as to convey them downwards to the transfer belt.

The characteristics and advantages of the belt loader according to the invention will be more apparent from the description of one embodiment of said loader given hereinafter with reference to the accompanying drawings which show the loader in diagrammatic form, and in which: Figure 1 is a side view; Figure 2 is a plan view; and Figure 3 is a perspective view.

The loader according to the invention comprises a load-bearing structure 10, which if required can be mounted on wheels to enable it to be easily moved. This load-bearing structure comprises a substantially horizontal support 11 which at one end is mounted to swivel about a horizontal axis 12, and at its other end rests on a telescopic column 1 3 of adjustable height.

By varying the height of the column 1 3 it is possible to incline the support 11 about the horizontal position in one direction or the other.

In the support 11 there are rotatably mounted a drive roller 14 and a deviation roller 1 5 for a first conveying belt 16. Above the upper active branch of the conveying belt 1 6 there is disposed a longitudinal lateral guide 17, the position of which is adjustable by handles 18.

The load-bearing structure 10 also comprises an upwardly inclined part 1 9 followed by a horizontal terminal ledge 20. The structural part 19, 20 supports a second transfer belt 21 which passes about a drive roller 22 and various deviation rollers 23, 24, 25, 26 and 27. The upper active branch of the transfer belt 21 comprises an initial upward portion followed by a horizontal portion.

In the upwardly inclined portion of the transfer belt 21 there are provided idle rollers 28 mounted on a swivel arm 29 pivoted at 30, said rollers resting by gravity on the articles upwardly conveyed by the transfer belt in order to ensure their correct transfer.

At the outlet end of the active portion of the transfer belt there is rotatably mounted a motorised roller 31 having its axis perpendicular to the direction of advancement of the articles, and located at the same height as the upper branch of the belt 21. With the motor ised roller 31 there cooperates a second upper roller 32 having its axis parallel to the first and carried idly by a swivel arm 33 in such a manner as to rest on the first.

The articles fed by the transfer belt 21 are then gripped between the two rollers 31 and 32, and are thrown into the feeder box shown diagrammatically at 34. The roller 31 is driven by its own geared motor 35 by way of a belt transmission 36.

For driving the two belts 1 6 and 21 there is provided a second geared motor 37 disnosed in the lower part of the load-bearing stucture 10. By way of a belt drive 38, the geared motor 37 directly drives the drive roller 22 of the transfer belt 21 at a relatively high speed.

Furthermore, by way of belt transmission 39, the said geared motor 37 operates a variator 40 which in turn operates the drive roller 14 of the conveying belt 1 6 by way of a belt transmission 41.

It should be noted that the linear speed imparted to the conveying belt 14 is always less than the (constant) linear speed imparted to the transfer belt 21. However, by means of the variator 40 it is possible to modify the ratio of these two speeds in order to adapt it to the requirements of the article being handled, and in particular to the thickness of said article.

As already stated, for thicker articles the linear speed of the belt 1 6 is chosen at a greater value and for thinner articles it is chosen at a smaller value.

It must also be noted that in the feeder box 34 there is provided a sensor, for example a photoelectric cell 42, which is arranged to sense the height of the pile of articles in said box. If this height falls below a predetermined level, the photoelectric cell causes the geared motor 37 to start, to thus drive the belts 1 6 and 21 of the loader in order to fill the box.

In contrast, the geared motor 35 is always in operation, even when the photoelectric cell 42 is obscured, in that its purpose is also to cause the containing guides of the feed bdx to vibrate. For this purpose, on the shaft of the throwing roller 31 there are mounted cams 43 which move the lateral guides 44 and rear guides of said box in order to ensure perfect stacking of the articles in the box.

Fig. 1 of the drawings clearly shows that the articles are disposed standing-up on the upper active branch (which moves from left to right in the figure) of the conveying belt 16, and abut against the lateral guide 1 7. The conveying belt 1 6 thus forms a mobile store on which the articles are placed manually, and which can have a capacity for example of between ten and thirty times the capacity of a feeder box.

At the outlet end of the conveying belt 16, the articles rest on each other and assume the inclination of the upper rising branch of the transfer belt 21. This latter belt then withdraws the articles and moves them upwards one at a time, to create their distribution in scale formation.

Because of the facility for adjusting and varying the linear speed of advancement of the conveying belt 16 by means of the variator 40, it is possible to obtain the most suitable distribution of the articles in scale formation of the transfer belt 21, independently of the thickness and rigidity of the articles being handled. Furthermore, by suitably inclining the active branch of the conveying belt 16, it is possible to facilitate the feed of any type of article, as already explained in detail heretofore.

Claims

1. A belt loader for signatures, sheets, magazines, catalogues and similar articles, for loading the feeders, provided with a box store, of packaging machines, binding machines and the like, comprising a first level conveying belt, followed by a second transfer belt having an initial rising portion and then a level portion, followed by a pair of expulsion rollers, said second transfer belt having a linear speed of advancement which is greater than the linear speed of advancement of the first conveying belt, characterised in that the first conveying belt is driven by means of an adjustable speed variator.

2. A belt loader as claimed in claim 1, characterised by comprising a single geared motor for driving the two belts, the speed variator being inserted into the motion transmission between said geared motor and the drive roller of the first conveying belt.

3. A belt loader as claimed in claim 1, characterised in that the first conveying belt is mounted on a support which is inclinable in the two directions about the horizontal position.

4. A belt loader as claimed in claim 3, characterised in that the support for the conveying belt is at one of its ends mounted to swivel about a horizontal axis transverse to the belt advancement direction, and at its opposite end rests on a telescopic column of adjustable height.

5. A belt loader constucted and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawngs.