GB2092060A

GB2092060A - Producing tubular bodies from flat flexible sheet materials

Info

Publication number: GB2092060A
Application number: GB8202646A
Authority: GB
Original assignee: NOVAMAQ SA
Current assignee: NOVAMAQ SA
Priority date: 1981-01-30
Filing date: 1982-01-29
Publication date: 1982-08-11
Also published as: ES8204343A1; IT1149511B; PT74361A; IT8219359A0; PT74361B; FR2498984A1; ES499524A0; DE3202943A1

Abstract

Equipment for forming tubular bodies from flat flexible sheet materials has a mould 1 against which the sheet material is shaped by compression means 2, 3 and 4. The sheet material enters the equipment at one end and is transported through the machine by conveyor belts 14, to leave the machine at the opposite end. An adhesive applying device 15 associated with the start of the belts 14 applies adhesive to one edge of the sheet material and the edges of the sheet, after forming of the tubular body, are compressed between tubular rollers 19, 20 to bond the edges of the sheet together. The rollers 19, 20 also assist in extracting the sheets from the equipment. <IMAGE>

Description

SPECIFICATION Equipment for producing tubular bodies from flat flexible sheet materials The present invention relates to improvements in equipment for producing tubular bodies from flat sheets of flexible materials such as e.g. carboard or other materials, these bodies being used for example for producing packagings such as drums having any shaping whether this be cylindrical, square or otherwise.

Such equipment is known in which a sheet of lamina of the appropriate flexible material is applied against a mould having an appropriate outer shaping. The sheet is adapted to the shape of the mould, after which the edges of the lamina employed, which are superimposed, are attached to each other using adhesive bonding or similar techniques.

In known equipment of this type, the feeding in is done of the flat sheets which are to be shaped onto the above-stated mould and, after their application to or shaping by the mould and the bonding operation whilst they are on the mould, they are removed from the same side, making use of the provision on the equipment of appropriate extractors following an "ironing out" of the region of bonding or adhesion of the superimposed edges of the sheet.

This arrangement, using feeding in of the sheets and withdrawal of the tubular bodies from the same side necessitates an excessive degree of mechanical complexity, especially as far as the arrangement of the extractors is concerned, but also concerning the compression of flattening means referred to above for the region of bonding of the edges of the sheet, which causes the output per unit time of such machines to be effectively quite small, which results in a slow productive output and a consequent increase in the price of the tubular bodies formed.

The improvements constituting the object of the present invention aim at overcoming the disadvantages referred to above, and allow machines which have been specially simplified to be provided as a result of the fact that the feed of the flat sheets which are to be shaped and their extraction is carried out in the linear sense, the sheets which are to be shaped entering at one side one after another and the shaped tubular bodies leaving, also one after the other and suitably guided, from the opposing end of the machine. In this way, it is possible to provide much higher manufacturing rates of output than is the case with existing machines, since the non-productive periods needed for extracting the shaped tubular bodies and introducing the fresh sheets to be shaped, are now eliminated.

Additionally, the improvements consituting the object of the present invention make it possible to provide extractors which, as well as carrying out the above task simultaneously act as a compressor means for the laminae, thus allowing the bodies concerned to be shaped in a practically continuous process and without interruption, the rate of output being determined by the action of the compression means for applying the Iaminae against the corresponding mould. In this way, the nonproductive periods are, a far as possible, eliminated and a considerable increase in the productive output of the machine is achieved.

The improvements constituting the object of the invention essentially consist in providing a transporting means at one end of the equipment constituted by two parallel endless belts, which are located at a level corresponding to that of the lower portion of the mould to which the flat sheet is to be applied, the latter, ready for shaping, being loaded onto this transport arrangement externally of the equipment and one after the other. The transport arrangement concerned penetrates into the working area of the equipment until it reaches the opposing end of the mould, below which and at the sides of which the compression means are situated for applying the flat sheet against the mould.Clearly, the compression means concerned will have a shaping of their surfaces which is applied to the sheet which will be matched to the shaping of the mould, so that the sheet becomes completely adapted to the shaping of the latter, leaving the region where the edges of the sheet are superimposed, free.

At a position adjacent to the endless belt at one of the sides of the transport arrangement, a continuous machine for applying a layer of adhesive to the lower face of the corresponding edge of the sheet is provided in such a fashion that, when the two edges are superimposed, these will become bonded to each other in the actual region of the mould, as a result of the application of pressure from a set of upper rollers which are alternately applied to and withdrawn from said region, in order to facilitate bonding of said edges and the formation of the tubular body. These movable sets of rollers are of the conventional type in use in known machines.

The extraction of the tubular body thus formed is achieved using a pusher device having a small path of travel, operated, for example, by means of a fluid-dynamic cylinder, which operates inside the mould and makes use of arms which slightly extend above the periphery of the latter through slots provided for this purpose, the extraction mechanism being completed bya set of pressure rollers which are located just above the region of superimposition of the edges of the shaped sheet and externally of the region of the mould referred to above, these being operated by the drive supplied by a suitable motor, the said rollers meeting up with the tubular body at the said region and causing it to travel to a position where it is outside the machine at the same time as, using high pressure between these, corresponding "ironing out" of said region of bonding is performed whilst the tubular body is sliding along or, stated in other terms, this all being done in a continuous operation which does not hold up the feeding in and shaping operation of a fresh sheet.

After leaving the said region where compression is exercised on the tubular body as it is drawn along in order to provide for its extraction, the tubular body is collected in a suitable collection means.

One important feature in accordance with the improvements indicated consists in provided ing lateral compression means for the sheet which is to be shaped on the corresponding mould which are advantageously made up by elbowed arms which are articulated at one of their ends and which, when operated by suitable drive means, preferably fluid-dynamic cylinders or the like, these perform angular motions which During them towards and away from the mould, which makes it possible to achieve savings on useful working space and enables the overall volume of the equipment to be considerably reduced.

An embodiment of the present invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatical view in lateral elevation equipment according to the present invention, in which, for the sake of clarity, the lateral compression means have been omitted; Figure 2 corresponds to a rear elevation view of the piece of equipment during the working stage of the compression means which perform shaping of the sheet; Figures 3 and 4 show, diagrammatically, the stages of extraction and compression of the region of bonding of the tubular body; and Figures 5 to 9 show various stages of the application of the sheet to the mould and its shaping thereon, in order to form the tubular body.

As will be seen from Figs. 1 and 2, the equipment is provided, in the conventional manner, with a mould 1, having an outer profile which corresponds to that of the tubular body which is to be formed, in this case a cylinder, it additionally being provided with a lower compression means 2, which initially causes the lamina L to be applied to the surface of and folded over the said mould, and two lateral compression means 3 and 4, which supplement the adaptation of the lam ina L to the mould 1.

The compression means involved, in accordance with the improvements consitituting the object of the invention are mounted at the ends of an equivalent number of elbowed arms 5, 6, which are articulated so as to be able to swing at their upper ends 7, 8 and are operated by the fluid-dynamic cylinders 9 and 10 respectively.

Above the region of juxtaposition of the edges of the lamina L, a compression means employing rollers, 11, is provided which is also of conventional construction, and this is able to perform advancing and retracting movements which are controlled by the fluiddynamic cylinder 12, and these movements allow it to exert pressure on those juxtaposed edges, which have previously been coated with adhesive, of the lamina L, or leave the said region free at the time when the tubular body thus formed is being extracted, as will be seen more clearly from what follows.

The lower compression means 2 is also controlled when performing its advancing and retracting movements by means of the fluiddynamic cylinder 1 3 and this arrangement as well is of the conventional type.

One characteristic feature of the improvements constituting the object of the invention consists in the fact that the feed of laminae L to the area where these are shaped around the mould 1 is provided by an endless conveying means made up by the two parallel belts 14, which are located at a level below the mould 1 and above the point of maximum descent of the lower compression means 2.

This conveying means which starts from a point external of the equipment penetrates into the working region of the latter until it reaches the far end of the mould 1, so that it is able to locate the laminae in the appropriate position for the compression means 2 to receive them and apply them correctly against the mould 1.

At one of the sides of said conveying means, a continuous adhesive-applying device 1 5 is provided and using this, a strip of adhesive A is applied to the whole length of one of the edges of the lamina L on one of its faces, in this case its lower face, as will be seen clearly in Fig. 5.

The body of the mould 1 is provided with a certain number of longitudinal slots 16, through which radial arms 1 7 pass, these being rigidly fixed to the plunger of a small fluid-dynamic cylinder 18, located externally of the equipment, which causes the arms to move inside the slots through a short distance, to cause the opposite edge of the tubular body formed from the lamina L to project freely from the mould 1.

At this opposite end of the mould 1, and externally of the latter, two rollers 1 9 and 20 are provided which are suitably supported and arranged so as to press against each other, so that they are able to grip the end of the tubular body leaving the mould, between them, and this in fact is actually done at the region corresponding to that of the super posed and bonded edges.The roller 1 9 is operated using an appropriate drive means 21, from a suitable motor means 22, in such a way that it drives the roller 20 in rotation so that the pair of these extract the tubular body from the mould 1, and at the same time carry out flattening of, or in other words strongly compress, the region of bonding of the edges of the lamina L to which adhesive was applied, thus reducing the thickness of said region as much as is possible as well as ensuring that the bonding of said edges is practically permanant.

At the outlet from the mould 1, the packagings which have been formed are deposited in a collection means made up by parallel rods 23, from which they are withdrawn in sequence.

The operation of a piece of equipment constructed in accordance with the invention is as follows: The laminae L, which are carried by the endless belts 14, are introduced until they reach a region which corresponds to that where the lower compression means 2 is adapted to act (Fig. 5), this compression means then raising the laimina L and applying it against the mould 1, and effectively folding it against the surface of the latter as can be seen in Fig. 6, and at this point the lateral compression means 3 and 4 swing. which complete the application of the lamina to the mould (Fig 7).

Prior to this, at the entry to the working region of the equipment, the adhesive-applying device 1 5 will already have applied a continuous strip of adhesive A to the whole length of the lower edge of the said lamina L, so that when the compression means employing the rollers is lowered whilst at the same time the lower compression means 22 is removed to allow the next lamina L to enter (Fig. 8), said rollers will press against the bonded region, thus causing the said edges to become firmly bonded to each other and leaving a finished shaped tubular body, this being the point at which the lateral compression means 3, 4 are also withdrawn (Fig. 9).

At this point, the extractor 1 7 comes into operation which causes the shaped tubular body to become slightly displaced towards the opposite end of the equipment, it then being picked up by the rollers 19, 20, which then extract it rapidly from the mould 1 and, by virtue of the pressure which they exert on each other, strongly compress the region of bonding, thus reducing the thickness of the same and strengthening the bond, the formed tubular body then finally being deposited in the collection means 23, which are preferably located at the same level as that of the mould 1.

It will be readily understood that although reference has been made to a cylindrical mould 1 in what has been described and shown in the drawings here, the latter could nevertheless possess any other external shape which is appropriate to the shaping needed for the packaging or the like which is to be made up using the body obtained. Thus, said mould could be rectangular, triangular, hexagonal or of any other shape, itWthen being only necessary to change the shape of the compression means 2, 3, 4, which should be adapted to the corresponding shaping required, this however not involving any changes whatsoever in the remainder of the components constituting the specific operating members of the equipment.

As will readily be seen, provision of the improvements in accordance with the invention can yield a large number of advantages: - the laminae L which are used to form the tubular bodies can be introduced one after the other, and without interruption, by the conveying means 14, at a rate of feed which it is impossible to achieve using equipment which is known at present, and is in use, of this type; - the bonding of the corresponding edge of each lamina is carried out simply by virtue of the provisions made for transporting the same, without prior preparatory operations being necessary; - extraction is faster, and along with this, the compression of the region of bonding is also achieved at one and the same time, without the need for independent mechanisms which carry out this operation; ; - in general, the non-productive times during manufacture are considerably reduced which, undoubtably results in a greater manufacturing output and as the nett result, the possible reduction of manufacturing and labour costs.

The materials, shapes and dimensions of the machines thus constructed are independent of the object of the invention as are the sheet materials which are employed in conjuction with it, as well as the auxiliary mechanisms and mechanical and fluid-dynamic bodies or the like which constitute it, and, generally, various accessory details may be incorporated in the machine without these leading to a change in its essential nature.

Claims

1. Equipment for forming tubular bodies from flat flexible sheet materials, having a mould over which the sheet materials which are to be shaped are applied using compression means which cause said sheet to adopt the shape of said mould, these being provided both below and laterally and having means for applying pressure to the region of juxtaposition and bonding of the edges of said sheet, the entry for the sheets to be shaped being provided at one of the ends of the equipment and the exit for the tubular bodies which have been shaped being provided at the other end, wherein the equipment has transport means for the material, the transport means at the entry for the sheets being associated with means for applying adhesive to one of the edges of the sheet to be shaped, whilst the transport means at the exit end work in conjuction with means for applying pressure to the region of bonding of said edges.

2. Equipment according to Claim 1, wherein the transport means at the entry for the sheets to be shaped are formed by two endless belts which are parallel and start from a position outside the equipment and introduce said sheets into the working region of the same at a position below the mould against which they are to be applied and above the lower compression means which apply and initially fold said sheets against the mould.

3. Equipment according to Claim 1 or Claim 2, wherein a continuous adhesive-applying device is located at one side of the transport means which deposit a layer or strip of adhesive along one of the edges of one face of the sheet, as the latter is gradually advanced towards the working region of the equipment.

4. Equipment according to any one of the preceding claims, wherein the extraction means for the tubular bodies which have been shaped around the mould include an urging means which moves longitudinally with respect to said mould over a short distance on the latter, and a set of drive rollers which are applied under pressure against each other, these being located at the opposite end of the mould so as to grasp the tubular body when the latter partially projects from said mould as a result of the operation of said urging means, said rollers being caused to move as a result of drive imparted from an appropriate motor means.

5. Equipment according to Claim 4, wherein the drive rollers which extract the tubular body from the mould are located in such a way that they act accurately on the region of bonding of the juxtaposed and bonded edges of the sheet constituting the tubular body, thus performing continuous compression of said region as extraction of the tubular body is carried out.

6. Equipment according to any one of the preceding claims, wherein the compression means which apply the sheet against the mould are rigidly mounted on elbowed arms which are pivoted so as to be able to swing, at one of their ends, and are operated by fluid-dynamic cylinders or similar mechanisms, so that they move in an angular fashion with respect to the mould.

7. Equipment for forming tubular bodies from flat flexible sheet materials substantially as herein described with reference to and as illustrated in the accompanying drawings.