GB2097325A - Making packaging elements - Google Patents

Abstract

A process of producing a packaging element from corrugated paper (14a) comprises feeding the paper through a gluing station (27, 28, 33) so that the paper is glued on one side, feeding the glued paper to a mandrel (37) having radially retractable and expandable blades (61) engageable in the corrugations of the paper, rotating the mandrel (37) with the blades in the expanded position to wind a length of the paper thereonto, cutting the paper using a cutting mechanism (48) when a predetermined length has been wound onto the mandrel to separate the wound paper from a supply thereof and transferring the wound paper tube from the mandrel (37) either manually or by means of a transfer mechanism (53, 54, 55) after the blades of the mandrel have been retracted, to a press which may be automatically operable with the machine or may be a separate mechanism. The machine for performing the process may be semi or fully automatically operable. <IMAGE>

Description

SPECIFICATION Machines for making packaging elements This invention relates to machines for producing packaging elements made from corrugated paper. The type of packaging element for which the machine is designed is made from corrugated paper rolled initially into a tube of several layers glued together, the tube then being flattened into any one of a number of forms having cross-sectional shape including flat elongated or L shape.

The process involved in the production of such elements comprises the steps of drawing the paper through a gluing section which applies glue to one side of the paper, rolling the paper onto a rotatable mandrel which rotates a predetermined number of times to produce, on the mandrel, a tubular structure of several layers, the paper then being cut off from the supply. The remaining tail of the paper then has to be stuck down onto the outside of the tube. The tube is then taken off the mandrel and transferred to a press which squashes it into the required flat or L-shaped or other constant cross-sectional configuration. It is necessary to hold the element in the press for an interval to ensure that it is set in the required shape.

There are in existence several types of machine for producing such packaging elements. In one form of apparatus, there is a first machine for gluing and rolling into the tubular shape and a separate machine which carries out the pressing stage. In the gluing and rolling machine, the cutting operation is made manually, as are the operations of engaging the paper on the mandrel and sealing the tail. Also removal from the mandrel, which is bladed to engage in the corrugations of the paper, is carried out manually, although it requires some effort. Thus this machine requires a full time operator.

The transfer to the other machine needs another operator and then the operation of that machine requires full time supervision for placing the tubes in the machine and then actuating it.

Then after a suitable interval each element must be extracted. The delay required for each element slows the production rate, though this can be alleviated by providing pairs of presses in the machine, which are used alternatively.

The object of the invention is to provide a machine for producing packaging elements in an efficient and economical manner, requiring a minimum of supervision.

According to the invention there is provided a machine for producing packaging elements made from corrugated paper comprising a gluing station, through which the paper passes to be glued, a cutting mechanism operable after a predetermined length of paper has passed, a rotatable mandrel onto which the paper is wound, a transfer mechanism to transfer the tube formed on the mandrel to a press part to press it into a required shape, an ejector for removing the finished element from the mandrel and the mandrel being provided with a number of blades to engage in the corrugations of the paper, the blades being retractable and extendable.

This provision of retractable blades on the mandrel aids both feeding of the paper onto the mandrel automatically and also removal of the tube for transfer to the press mechanism.

The invention will now be described by way of example with reference to the accompanying drawings in which; Figure 1 is a front view of a machine for making packaging elements constructed in accordance with the invention, Figure 2 is a schematic end elevation view of the machine, Figure 3 is a cross-sectional view of one form of mandrel used in the machine, Figure 4 is a cross-sectional view of another form of mandrel and, Figure 5 is a cross-sectional view of a further form of mandrel used in the machine.

With reference to Figures 1 and 2 the machine is intended for fully automatic operation requiring a minimum of supervision. The machine is in two main parts comprising a gluing and rolling part and a press part. The gluing and rolling part is shown in detail in Figures 1 and 2 whereas the press part is indicated only in outline in Figure 1 and is indicated thereon by numeral 9.

The gluing and rolling part has a frame including legs 10 with adjustable feet 11. The frame carries supports 1 2 for a shaft 1 3 onto which a supply of corrugated paper is shown mounted. This supply roll is indicated by numeral 14. The type of corrugated paper normally used is of the kind having a plain sheet of paper attached to one side of a corrugated sheet. In the supply roll 14 the flat sheet is presented outwardly.

The frame 10 also carries, at one side, a main drive electric motor 1 5 which, through a suitable gearbox 16, drives a pulley or sprocket 1 7 which provides the drive to various mechanisms in the machine. The pulley or sprocket 1 7 engages a belt or chain 1 8 running on a pulley or sprocket 1 9 mounted on a spindle 21. The spindle 21 also carries a further pulley or sprocket (not illustrated) over which engages a further belt or chain 22. This in turn engages on pulleys or sprockets 23, 24 engaged on respective spindles 25, and 26.

The spindle 21, on which the pulley or sprocket 19 is mounted, carries a lower gluing roller 27.

This extends across the width of the machine and has its periphery in rolling contact with a glue applicator roller 28. This dips into a bath 29 of glue so that an even layer of glue is applied onto the lower gluing roller 27. The glue bath 29 is mounted on the frame. The glue applicator roller 28 is mounted on a spindle 31 which is thus parallel with the spindle 21 for the lower gluing roller 27. Manual adjustment means, indicated at 32, are provided for adjusting the contact or clearance between the lower gluing roller 27 and the glue applicator roller 28.

An upper gluing roller 33 is driven through gearing (not shown) from the spindle 26 and this is therefore arranged to rotate in a direction opposite to the lower gluing roller 27. These rollers represent the gluing station.

In Figure 2 the web of corrugated paper is indicated at 1 4a coming off the supply roll 14.

This is shown passing over a guide roller 34 and into the gluing mechanism. It passes above the glue applicator roller 28, without of course touching it, and it passes between the upper and lower gluing rollers 27 and 33 and is drawn therethrough by the nip between the two rollers.

In the process of passing between these rollers glue is applied to the corrugated side of the paper.

The paper then passes over the upper gluing roller 33 to travel in the opposite direction to its approach to the gluing rollers 27 and 33 but at a higher level. It passes onto a platform indicated at 35 and is drawn across this by means of a series of toothed wheels 36 mounted on the shaft 26 which also carries the pulley or sprocket 24. The toothed wheels are mounted on the shaft 26 at spaced intervals across the machine as indicated in Figure 1. Preferably the toothed wheels 36 are made from plastics materials such as nylon and have teeth (not shown) equal to the spacing between the corrugations in the paper being fed.

The paper is fed across the platform 35 towards a mandrel indicated at 37 in Figures 1 and 2. As shown in Figures 3, 4 and 5 three different types of mandrel may be used, depending upon the internal diameter of a tube of corrugated paper to be produced. Further reference will be made later to the description to these mandrels.

The mandrel has a length substantially less than the width of the machine and therefore also of the width of the paper web, as indicated in Figure 1.

The mandrel is mounted on a tube 38 carried from one end of the machine. Within the tube is a rod 39 (see Figures 1 and Figures 3, 4 and 5), by means of which mandrel expansion is carried out (as will be explained). The tube 38 and rod 39 are attached to an expanding actuating mechanism indicated generally at 41 in Figure 1. This is driven from a motor 42 situated below the mechanism and connected with it through a right angled drive unit 43 and a belt or chain 44. By means of this mechanism the mandrel is rotated about its axis which is therefore parallel with respect of the axis of the shaft 26 carrying the toothed wheels 36.

Partially surrounding the mandrel 37 are guides for the paper web. These comprise an upper arcuate guide 45 and a lower arcuate guide 46.

These are adjustable as indicated by the arrows in Figure 2. The purpose of the guides is to curl the paper web arriving from the platform 35 so that it takes up a position around the mandrel 37. The mandrel is rotated in unison with the advancing toothed wheels 36 so that the paper becomes coiled around the mandrel. The mandrel has blades (as will be described) which engage in the corrugations of the papers to ensure positive drive.

Beneath the mandrel is a movable shallow V shaped plate 47 which, unlike the guides 45, 46 extends for the full width of the machine. This plate 47 is movable as indicated by the arrows in Figure 2, between a retracted or lower position in which it does not interfere with the incoming free end of web of corrugated paper and an upper position in which it is shown in Figure 2.

Between the advancing toothed wheels 36 and the mandrel assembly there is a cutting mechanism for severing the paper when a predetermined length has been wound onto the mandrel. The cutting mechanism includes a unit 48 carrying a rotary knife disc 49 which is driven through a small electric motor mounted in the unit. The unit 48 is mounted for lengthwise sliding movement on a guide 51 which extends across the machine. To drive the unit 48 along the guide there is a mechanism which is actuated in accordance with a signal received from a control unit, as will be described.

Above the guide 51 is a further guide 52 for a transfer unit 53 which is designed to push a formed tube off the mandrel and into the press part 9 of the machine. This transfer unit 53 includes an arm 54 which carries a collar 55 surrounding the mandrel tube 38. At an appropriate stage in the automatic operation of the machine the transfer unit 53 is actuated and slides from the position shown in Figure 1 towards the opposite end, thus taking the completed paper tube off the mandrel and transferring it into the press part 9 of the machine. At the top of the machine there is actuating mechanism, indicated generally at 56, for the transfer and cutting mechanisms.

Referring to Figure 3, a first form of mandrel is shown. The tube 38 is shown at the left hand end and serves to support the mandrel. Within this is the rod 39 which is axially slidable by means of the actuating mechanism indicated at 41 in Figure 1. Within the end of the tube 38 is a part 57 having a stepped bore to guide the rod 39.

Surrounding a smaller diameter portion of the part 57 is a sleeve 58 having an end cap 59 at its end remote from the tube 38. The sleeve 58 has slots in which are engaged blades 61, of which there are four in this example. The blades are retained in their slots by expandable wire rings 62 at their opposite ends. Connected to the end of the rod 39 is a cam rod 63 carrying two spaced conical cams 64, 65. These cams engage in shaped cut-outs in the internally directed edges of the blades 61 near opposite ends thereof respectively. In Figure 3 the cam rod 63 with the cams 64, 65 is shown in the two extreme positions, above and below the centre line. Below the centre line the cams 64, 65 are shown occupying their respective cut-outs in one of the blades 61 so that the latter has its external edge only slightly proud of the surface of the sleeve 58 in which it is guided. Above the centre line, the cam rod 63 with cams 64, 65 are shown moved to-the left so that the cams are out of the cut-outs in the blade 61, which is thus pushed outwardly radially from the sleeve 58. The conical cams 64, 65 actuate all the blades 61 simultaneously between retracted and extended positions.

Figure 4 shows an alternative mandrel in which the same components are used except for the blades 66 which are of larger width so as to accommodate a larger internal diameter for the tube of corrugated paper to be formed.

In Figure 5 a still further form of mandrel is used, this being for accommodating still larger internal diameters of the tube of corrugated paper to be formed. In this example the tube 38 is connected to a sleeve 67 through a member 68, equivalent to the members 58 and 57 in the Figures 3 and 4 constructions. The sleeve 67 however has attached to it, two sets of four radial guides 69. Each set is axially aligned and contains respective plungers 71. Within each plunger 71 is a bar 72 pivoted at its outer end to a blade 73, near its end. The blades 73 are surrounded at their respective ends by expandable wire rings 74 which serve to retain the rods 72 in their plungers 71. A hollow casing 75 encloses the plungers 71 and the sleeve 67. The plungers 71 are flanged at their outer ends and are secured to the housing 75 by rivetting as indicated at 76.

Within the sleeve 67 and guided by the member 68, a cam rod 77 is provided. This is connected to the rod 39 in similar manner to that in Figures 3 and 4. Spaced double ended conical cams 78, 79 are provided on the cam rod 77 at positions to engage the plungers 71. The cam rods and cams are shown in their two alternative positions above and below the centre line. Below the centre line they are shown engaging the plungers 71 and pushing them outwardly so as to push the blades 73 to their outer or extended positions. Above the centre line the cams 78, 79 are shown out of engagement with the plungers 71 so that the blades 73 are at their inward or retracted positions. The housing 75 has sufficient resilience to allow such expansion and contraction to take place. Conveniently it is made from rubber.

In operation, the paper is taken off the supply roll 14 and passes over the guide roller 34 and through the gluing station as described. Glue is applied to the corrugated side of the paper and then passes across the platform 35 with the corrugated glued side uppermost. Advancement is carried out by means of the toothed wheels 36.

The paper leading edges now passes off the forward end of the platform 35 and tends to drop onto the lower guide 46. The arcuate shape of this curls the leading edge upwardly and over the mandrel. The upper guide 45 assists in this curling motion over the mandrel. At this time the mandrel blades are retracted but as soon as the paper has passed substantially right around the mandrel the blades are extended so that they enter respective corrugations in the paper. The mandrel is now rotated at a speed which forms a tube tightly on the mandrel, successive layers becoming stuck to one another by means of the pre-applied glue.

When the tube has reached a required external diameter, a signal is received at the cutting unit 48 to send it across the paper to cut it off along a straight line. At this time it is necessary to stop the advance of the paper so that a straight cut is achieved. The mandrel is then rotated a short distance further while the plate 47 is brought up beneath it. The purpose of this is to stick down the tail of the paper to form a complete tube.

The next stage is to retract the mandrel blades so that the formed tube is only freely engaged on the mandrel. The transfer mechanism 53 is now actuated to push the formed tube into the press part of the machine.

The sequence is repeated to form successive tubes automatically.

The press part of the machine has two side by side press zones into which tubes are fed alternately. A carriage moves the press mechanism backwards and forwards so as to present one of the press zones in alignment with the transfer from the mandrel in turn. In each press zone the tube is squashed to form flat, L shaped or other section member. Where L section members are formed the internal angle of the L is pressed in to a greater extent and this assists in retention of the L shaped configuration. It is necessary to leave the member in the press zone for a predetermined period to ensure that it takes up the correct set and is firmly glued in that condition.

Upon completion of pressing, the completed packaging element may be ejected by contact with the next one coming into the press part of the machine.

An automatic ejector may however be provided to ensure positive extraction of the completed element from the machine. The arrival of a new tube from the mandrel by means of the transfer mechanism 53 serves to push the preceding formed element into the ejector which is in the form of rotating vertical rolls at the side of an opening through which the element is to be extracted.

Any one of the mandrel forms shown in Figures 3, 4 and 5 can be used, depending upon the internal diameter of the completed packaging element to be formed. Appropriate automatic preferably electrical control mechanism is provided to control sequential operation of the different parts of the machine as described.

It is possible to simplify the machine to make it semi-automatic and in this case an operator is needed to carry out certain of the functions. In such machine the operator would be responsible for taking the leading edge of the web and winding it manually onto the mandrel, which for this purpose has its blades in the extended position. A switch is then operated to wind the paper onto the mandrel a predetermined number of revolutions. An automatic stop arrests further advance of the paper and actuates the cutting unit. Upon completion of the cutting operation the mandrel will be advanced to wind the tail of the paper onto the exterior of the tube formed on the mandrel and this also advances the paper leading edge ready for the next operation. The mandrel will then be collapsed and the transfer will take place manually into the press part of the machine.

With such a mechanism it is also possible for the press part of the machine to be at a separate location but this has the disadvantage of the need for transfer and manual feeding into such press part of the machine.

Claims (16)

1. A machine for producing packaging elements made from corrugated paper comprising a gluing station, through which the paper passes to be glued, a cutting mechanism operable after a predetermined length of paper has passed, a rotatable mandrel onto which the paper is wound, a transfer mechanism to transfer the tube formed on the mandrel to a press part to press it into a required shape, an ejector for removing the finished element from the mandrel and the mandrel being provided with a number of blades to engage in the corrugations of the paper, the blades being retractable and extendable.

2. A machine as claimed in claim 1 wherein the gluing station includes driven rollers whereby the paper is glued on one side and advanced towards the mandrel.

3. A machine as claimed in claim 1 or claim 2 wherein guides adjacent to the mandrel serve to curl the paper on to the mandrel.

4. A machine as claimed in claim 3 in which a further retractable guide is situated near to the mandrel to assist in sticking the tail or trailing end of a paper length down, to complete the rolling and sticking of a packaging element on the mandrel.

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5. A machine as claimed in any one of the preceding claims in which the mandrel comprises a tube, means for rotating it about its central axis, a cam rod axially slidably mounted within the tube, the cam rod having cams arranged to actuate blades and axial sliding movement of the cam rod causing the cams to actuate the blades to move them outwardly or to disengage the blades to allow them to move inwardly.

6. A machine as claimed in claim 5 wherein the cams act directly on the blades to move them radially inwardly and outwardly through slots in the tube.

7. A machine as claimed in claim 5 in which the cams act on plungers which are connected with the blades, the plungers being radially slidably engaged in the tube.

8. A machine as claimed in claim 7 wherein the plungers and the tube are enshrouded in a flexible sleeve through which the plungers extend to carry the blades.

9. A machine as claimed in any one of the preceding claims wherein the transfer mechanism is a device which acts on the end of a packaging element on the mandrel in the direction of its axis to drive the element off the mandrel, when the blades of the mandrel are in retracted position.

10. A machine as claimed in any one of the preceding claims wherein the press part of the machine has two sections which can be moved alternatively into position to accept an element from the mandrel.

11. A machine as claimed in any one of the preceding claims wherein automatic sequential operation of the machine is carried out with a control means.

12. A process for producing packaging elements comprising feeding corrugated paper, in a machine, to a gluing station, at which one side of the paper is glued, advancing the paper onto a mandrel, the mandrel having expandable blades, which are in their expanded condition rotating the mandrel to wind a length of the paper onto the mandrel, cutting off the paper when a predetermined length has been wound onto the mandrel, retracting the blades of the mandrel and then transferring the element so made to a press part to press it into a required shape, and removing the element from the press part.

1 3. A process as claimed in claim 12 wherein controls are provided for automatically moving the paper through the machine, for actuating the mandrel, for transferring the element to the press part, pressing it and removing it.

14. A process as claimed in claim 12 or claim 13 wherein the feed of the paper is stopped when the paper is cut off, so that a straight cut is made.

1 5. A process as claimed in any one of claims 12, 13 or 14 in which the paper is guided on to the mandrel by guides and the tail or trailing end is sealed down by means of a moving plate.

16. A machine for producing packaging elements made from corrugated paper, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

1 7. A process for producing packaging elements, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.