WO1995003936A1

WO1995003936A1 - Mandrel, fitted machine and packaging piece

Info

Publication number: WO1995003936A1
Application number: PCT/GB1994/001617
Authority: WO
Inventors: Timothy Corben Morley
Original assignee: Aston Packaging Limited
Priority date: 1993-07-27
Filing date: 1994-07-27
Publication date: 1995-02-09
Also published as: GB9315475D0; AU7233994A

Abstract

This invention relates to a mandrel (14), fitted machine, and packaging piece and relates in particular to a mandrel for winding corrugated paper (10) and to a machine fitted with the mandrel for preparing a roll of corrugated paper (22) suitable for offering to a press, the press being of a type to form a shaped packaging protective piece. There is provided a mandrel (14) for winding a roll of corrugated paper (22) which includes at least one paper engagement member (24) mounted on the mandrel and drive means (32, 42) for the engagement member, there being a positive coupling (36, 40) between the drive means and the or each engagement member. There is also provided a packaging piece made by a process which includes the steps of {1} engaging a corrugation of the paper (10) by an engagement member (24) carried by a hollow mandrel (14), the mandrel having a rotational axis, the engagement member being coupled to a drive means (32, 42) movable in a first axial direction within the mandrel to cause the engagement member to project from the mandrel; {2} rotating the mandrel to draw the corrugated paper onto the mandrel; and {3} positively retracting the engagement member by movement of the drive means in a second axial direction opposed to the first axial direction whereby to permit the wound roll to be removed from the mandrel.

Description

MANDREL, FITTED MACHINE AND PACKAGING PIECE

FIELD OF THE INVENTION

This invention relates to a mandrel, fitted machine, and packaging piece and relates in particular to a mandrel for winding corrugated paper and to a machine fitted with the mandrel for preparing a roll of corrugated paper suitable for offering to a press, the press being of a type to form a shaped packaging protective piece.

BACKGROUND TO THE INVENTION

Packaging protective pieces are used to protect the exposed outer surfaces of products, particularly the sides and corners of rectangular articles, both in the warehouse and during transit.

Such packaging pieces have a relatively short commercial life. Suitably therefore they should be of a material which is easily disposable after use. Desirably they should be made from renewable or recycled materials to limit the consumption of natural resources.

Corrugated paper is often made from recycled waste paper. Since users are increasingly demanding materials which meet the requirements mentioned above, the more widespread use of formed corrugated paper in preference to other packaging materials, for instance the oil-based packaging materials such as polystyrene, is expected.

In addition, formed corrugated paper such as angled corrugated paper of "L" section, is valued for its exceptional cushioning against repeated impacts, as well as its resistance to longitudinal crushing such as might occur if heavy articles with angled corner protection are stacked one upon another.

DISCLOSURE OF THE PRIOR ART

A packaging piece such as an edge protector has been made by a process which includes drawing corrugated paper onto a mandrel mounted in cantilever and rotatably driven whereby to form a paper roll around the mandrel, removing the roll from the unsupported end of the mandrel by sliding it along the mandrel parallel to the mandrel axis, and then offering the removed roll to a former to form the roll into the desired configuration of corrugated packaging piece.

Such a process, as well as the use of mandrels of different designs and the provision of a fitted machine, is disclosed in our British patent 2,097,325. It is there taught that the corrugated paper is drawn onto and around the mandrel by mandrel blades. One disadvantage of the earlier mandrel arrangements is that if one (or more) of the blades is not fully withdrawn, or not withdrawn in time, then the inner coil of the roll can inadvertently be engaged and held as the outer coils of the wound roll are removed axially of the mandrel, with possible partial "axial unwinding" (if, as is usual, the adhesive has not set), and/or ripping of the paper.

Thus in the known arrangement, not only is the initial position and adjustment of the blades critical in order that the machine operator will be assured that the blades will properly be withdrawn prior to operation of roll "axial removal means", but this position and adjustment needs consistently to be maintained during subsequent roll removal operations. This latter has proved especially difficult to achieve in practice, particularly when, as is usual, the paper has been pre-coated with a flowable cold-setting adhesive (so that the roll when removed from the press after the subsequent forming step, will retain its formed shape); as one difficulty, adhesive which has flowed onto the mandrel adjacent a blade is known to inhibit the necessary timely and speedy retraction of that blade from engagement with the inner coil of the wound roll.

DISCLOSURE OF THE INVENTION

According to one feature of the invention we provide a mandrel for winding a roll of corrugated paper which includes at least one paper engagement member mounted in the mandrel, engagement member drive means mounted in the mandrel, and a positive coupling between the drive means and the engagement member.

The positive coupling in particular can ensure that movement of the drive means in one direction relative to the mandrel will result in inwards movement of the engagement member relative to the mandrel. Preferably the positive coupling will also ensure that movement in the opposite direction will result in outwards movement of the engagement member.

The engagement member and the drive means therefor are both carried by the mandrel. Usefully there are a plurality of engagement members, typically three or perhaps four, each coupled for simultaneous inwards movement of the respective engagement member whereby to free from obstruction by an engagement member the removal of the wound roll from the mandrel.

The direct coupling will desirably be such that movement of the drive means can be selected also to result in outwards movement of the engagement member from the mandrel, into a paper engagement condition, whereby to effect a positive forward drawing of the paper so as to permit it to wind around the mandrel. Thus desirably fore and aft movement of the drive means parallel to the rotational axis of the mandrel and within and relative to the mandrel will result in respective radially outwards and inwards movement of the paper engagement member(s) .

Usefully the engagement member is a blade sized to engage with and within a corrugation of the paper.

Preferably the positive coupling comprises a pin and slot, one respectively on the drive means and a part coupled to the engagement member e.g. the blade, the slot having a first end closer to the axis of the drive means than the other end. Usefully the slot is linearly disposed, at an angle in the range 30 to 60 degrees to the axis of the drive means.

The provision in a mandrel according to the invention of a positive coupling between the drive means and the blade or equivalent engagement member permits the transmission to the blade of a force sufficient to rupture adhesive which has set or partly set around the blade, this being a particularly important feature for correct and timely blade withdrawal, for unimpeded roll removal from the mandrel.

In particular, when the positive drive means is a pin and slot, adhesive encroaching into the mandrel and cold-setting either upon the pin or in the slot is likely to be readily ruptured since the contact surface area between the pin and slot is small. According to a further feature of the invention we provide a packaging piece such as an edge protector made by a process which includes engaging a corrugation of the paper by an engagement member carried by a hollow mandrel, the engagement member being coupled to a drive means movable in a first axial direction within the mandrel to cause the engagement member to project from the mandrel, rotating the mandrel to draw the corrugated paper onto the mandrel, and retracting the engagement member by movement of the drive means in a second direction opposed to the first direction whereby to permit the wound roll to be removed from the mandrel. Preferably the engagement member has substantial length in the said first and second directions, and forms a continuous blade, though in an alternative embodiment the length can be castellated at its paper engagement surface to form a series of spaced fingers. Each engagement member will be of a size and shape to fit into a corrugation i.e. between successive apices of the corrugated form.

Preferably the mandrel will be mounted in cantilever and the process will include rotating the mandrel from one end whereby to form a paper roll around the mandrel and between the ends thereof, and removing the roll from the unsupported end of the mandrel by sliding it along the mandrel parallel to the mandrel axis.

We also provide a winding machine with a mandrel as disclosed, adapted to utilise the process as described. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:-

Fig.l is a side sectional view of part of a roll winding machine, having a mandrel according to the invention, shortly after the start of a roll winding cycle;

Fig.2 is a view as for Fig.l, shortly before the end of a roll winding cycle;

Fig.3 is a side sectional view of the mandrel of Fig.l; and

Fig.4 is a sectional view along the line IV-IV of Fig.3.

DISCLOSURE OF EXEMPLARY EMBODIMENTS

The paper 10 to be wound is single faced, with one layer 11 of plain paper bonded to a second layer 12 which is corrugated. The spaces between the corrugations are engaged by the teeth of a feed roller (not shown), which can be rotated in order that the paper is fed to the right as viewed in Fig.l, i.e. towards the mandrel 14. Typically the paper 10 will have been presented from a supply roll (not shown), having been withdrawn therefrom between a pair of nip rollers, one of which paints the corrugation tips with a cold-setting adhesive. In one embodiment the length of paper to form the wound roll will be cut from the supply by a "paper cutter" movable axially parallel to the mandrel axis only after the required length of paper has been wound on the mandrel, and with the mandrel stationary to ensure a straight line cut parallel to the mandrel rotation axis. In an alternative but less preferred embodiment the paper lengths can be pre-cut from the supply, perhaps even before being painted with adhesive, and fed to the winding machine in sheet form.

Partially surrounding the mandrel 14 are guides 16,18 for the paper. In this embodiment the guide 16, which is uppermost as viewed in Figs. 1 and 2 is movable linearly towards and away from the mandrel 14 whilst the guide 18 is pivotable (in known fashion) about pivot 20 towards and away from the mandrel. The guides are moved towards the mandrel during winding of the paper (Fig.2) but are withdrawn therefrom upon completion of the winding stage, prior to the wound roll 22 being removed from the mandrel i.e. as by being axially slid therealong, and ejected sideways from the machine ready for the subsequent pressing operation into a formed corrugated paper piece. As viewed in Fig.l, the mandrel rotates anti-clockwise for paper winding. One or more guide members 27 are provided to ensure that the leading edge of the paper is guided "underneath" the mandrel 14; these guide members will be of particular importance if the paper is prone to curling, as may be the case towards the end of a supply roll i.e. for the last paper to be withdrawn. The guide members are movable by pneumatic pistons 28 between the extended condition of Fig.l and the retracted condition of Fig.2; the retracted condition permits the passage of a known paper cutter (not shown) for the purpose already explained.

The outer diameter of the wound paper roll is determined both by the size of the mandrel and by the number of rotations of the mandrel (before the mandrel rotation is stopped, to permit the paper to be cut from the supply); it is thus important to use at least one (and preferably three, perhaps four) angularly spaced engagement members (each perhaps a finger or a series of axially spaced fingers, but each preferably being axially extended to form a blade) whereby to prevent or limit angular slippage of the paper relative to the mandrel.

At the start of each roll winding cycle, the mandrel 14 has its blades 24 in a contracted condition i.e. the blades are partially withdrawn into the mandrel (Fig.l). In another embodiment, the blades in their contracted condition are fully withdrawn into the mandrel, so that they do not engage the wound roll during its removal from the machine. In an alternative embodiment the wound roll is supported upon trays so that the wound roll remains substantially coaxial with the mandrel and the partially withdrawn blades do not contact the wound roll during its removal from the machine.

The mandrel is rotated about its axis and concurrently the paper is moved towards the mandrel 14, the design of mandrel in a preferred embodiment being selected in accordance with the internal diameter of the roll 22 of corrugated paper to be produced.

The guides 16,18 are brought towards the mandrel to guide the paper around the (rotating) mandrel. When the paper covers between one half and two thirds of the circumference of the mandrel, the blades are moved to their expanded condition i.e. moved outwardly of the mandrel (Fig.2), in this embodiment radially. The blades 24 engage the corrugations of the paper 10, so carrying the paper around the mandrel, the mandrel continuing to rotate for the required number of rotations to form a roll 22 of the desired size.

The mandrel 14 has a length (parallel to its rotational axis) substantially less than that of the effective width of the machine and therefore also of the width of the paper roll to be formed, or which can be formed. As seen in Fig.3, mandrel 14 is mounted on mandrel shaft 30 which can be rotated by conventional means. Inside the shaft 30 and lying substantially along the rotational axis of the mandrel 14 is the operating rod 32 for the mandrel blades 24 whereby the blades 24 can be moved outwardly and inwardly of the slots or openings 26 in the mandrel outer cover 25 (Fig.4).

The blades 24 each have two angled slots 36. The slots each embrace a pin 40 carried by a drive plate 42 (see also Fig.4). The drive plates 42 are interconnected by operating rod 32, and can thus simultaneously be moved thereby to the left and right as viewed in Fig.3. Thus, in this embodiment, the drive means comprises the operating rod 32, and the drive plates 42.

The drive plates each have four apertures 44, the apertures 44 permitting the drive plates to be slidably mounted upon tie bars (not shown) , a respective end of each tie bar being connected to the mandrel end plates 46,48.

Axial movement of the rod 32 will cause corresponding movement of the drive plates 42. Movement of the rod 32 to the left in Fig.3 will cause the blades 24 to be withdrawn into the mandrel 14 by engagement of pin 40 with an edge of slot 36. Movement of the rod to the right in this figure will cause the blades 24 to move outwardly of the mandrel by engagement of the pin 40 with the opposed edge of slot 36. The machine also includes an ejector mechanism (not shown) by which the wound roll may be removed in conventional manner from the machine. Thus the ejector mechanism can abut an end of the wound roll and remove it parallel to the axis of rotation of the mandrel, but it will be understood that first the blades or other engagement members must have been properly retracted i.e. otherwise they can foul the inner coil of the wound roll and perhaps cause "axial" unwinding, the adhesive at this time still being liquid, and not set.

Thus when the winding of the roll is complete, the blades 24 are partially or fully withdrawn into the mandrel 14, not only so that the roll ejector may pass the mandrel, and so that the force required to remove the roll from the mandrel is reduced, but also so that the wound roll is not damaged.

The ejector can be of annular form and mounted solely for linear movement, as generally disclosed in our prior British Patent 2,097,325, or the ejector can be of part-annular or other suitable shape and movable both axially and laterally as generally disclosed in our co-pending British patent application 9311072.4 (filed on May 28, 1993) and with the advantage therein described.

It will be understood that, particularly with larger-diameter mandrels, a single mandrel according to this invention can be used to produce wound rolls of varying size. The internal diameter of the wound roll is dependent upon the "expanded" size of the mandrel i.e. the expanded radius of blades 24, and this expanded size is dependent upon the relative positions of the pins 40 in slots 36. Thus the start position i.e. the preliminary axial movement of rod 32 may be chosen, specifically it may be preselected, to achieve the required internal (start) diameter of the roll; the external diameter of the roll is then determined by the (pre-selected) number of mandrel complete or partial rotations.

A blade of the mandrel herein described may be replaced by two or more blades co-axially spaced respectively apart along the length of the mandrel, the radial position (roll engagement/disengagement) of each of the blades being controlled by a separate drive plate.

Claims

1. A mandrel (14) for winding a roll of corrugated paper (22) which includes at least one paper engagement member (24) mounted on the mandrel and drive means (32,42) for the engagement member, characterised by a positive drive coupling (36,40) between the drive means and the or each engagement member.

2. A mandrel according to claim 1, the mandrel having an axis of rotation, characterised by axially movable drive means whereby movement of the drive means in a first axial direction causes movement of the engagement member in a first substantially radial direction and movement of the drive means in a second opposed axial direction causes movement of the engagement member in a second opposed substantially radial direction.

3. A mandrel according to claim 1 or claim 2 characterised in that the or each engagement member and the drive means are mounted in the mandrel.

4. A mandrel according to any of claims 1-3 characterised in that the positive drive means includes at least one pin (40) and slot (36), one of the pin and slot respectively being mounted on the drive means (32,42) and the other of the pin and slot respectively being mounted on the engagement member (24), the slot having a first end and a second end, the first end being closer to the mandrel rotation axis than the second end.

5. A mandrel according to claim 4 characterised in that the slot is substantially linear, and is disposed at an angle of between 30° and 60° to the said rotation axis.

6. A mandrel according to any of claims 1-5 characterised in that the drive means comprises an operating rod (32) and two drive plates (42), and in that the operating rod is substantially parallel to the mandrel rotation axis.

7. A mandrel according to claim 6 characterised in that the drive plates are subtantially perpendicular to the axis, and in that the drive plates are slidably mounted upon tie bars.

8. A mandrel according to any of claims 1-7 characterised in that there are at least three engagement members (24), and in that each said engagement member is an axially extending blade.

9. A winding machine for producing a wound roll of corrugated paper (22), the machine having a mandrel (14) according to any of claims 1-8.

10. A packaging piece made by a process which includes the steps of (l) engaging a corrugation of the paper (10) by an engagement member (24) carried by a hollow mandrel (14), the mandrel having a rotational axis, the engagement member being coupled to a drive means (32,42) movable in a first axial direction within the mandrel to cause the engagement member to project from the mandrel; {2} rotating the mandrel to draw the corrugated paper onto the mandrel; and (3) positively retracting the engagement member by movement of the drive means in a second axial direction opposed to the first axial direction whereby to permit the wound roll to be removed from the mandrel.