AU701393B2

AU701393B2 - Apparatus and method for forming lightweight pallets

Info

Publication number: AU701393B2
Application number: AU57554/96A
Authority: AU
Inventors: Ross Chiodo; John Mammoliti; Alex Ong
Original assignee: Visy Board Properties Pty Ltd; Visy Board Pty Ltd
Current assignee: Visy R&D Pty Ltd
Priority date: 1995-05-31
Filing date: 1996-05-29
Publication date: 1999-01-28
Anticipated expiration: 2016-05-29
Also published as: AU5755496A

Description

PCTAU O3 2 RECEIVED 2 7 iAY 7 1

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APPARATUS AND METHOD FOR FORMING LIGHTWEIGHT PALLETS Field of the Invention This invention relates to an apparatus and method for forming lightweight pallets and other structures formed from wound strips of corrugated board or paper.

Background of the Invention In Australian Patent Application No AU-B-38398/93 and International Patent Publication No W095/18752, we have described a lightweight pallet formed from tightly wound single-face corrugated board. The pallets described in these documents were constructed by the inventors by hand winding and manual positioning of the appropriate mandrels. This is not only time-consuming but also may result in a less than accurately formed product, the timing of positioning of the mandrels as the corrugated board is wound being critical.

Summary of the Invention and Object It is an object of the present invention to provide an apparatus for winding strips of corrugated board or paper into a shaped structure, such as a lightweight pallet of the type described in the Applications identified above.

The invention provides an apparatus for forming structures of tightly wound paper, cardboard or corrugated board, comprising means for supporting a roll of paper, cardboard or corrugated board, means for tensioning said paper, cardboard or corrugated board as it leaves said roll, means for advancing said paper, cardboard or corrugated board from said roll to a forming reel, means for applying adhesive to at least one side of said paper, cardboard or corrugated board, means for attaching the free end of said paper, cardboard or corrugated board to said reel to enable the paper, cardboard or corrugated board to be wound onto the reel, mandrel means associated with said reel forming adjacent shaped openings in the wound paper, cardboard or corrugated board, and means for severing said paper, cardboard or ad, AMENDED SHEET

P~IFAIAU/

WO 96/38291 PCT/AU96/00325 2 corrugated board when the wound structure is complete.

In one form of the invention, a slitting means is provided ahead of the advancing means to slit the paper, cardboard or corrugated board into multiple strips, with the strips being fed in unison to the advancing means. Where the structure is to be formed from single-face corrugated board, the adhesive applying means is positioned to apply adhesive to the corrugated side of the strips so that adjacent layers of the strips are adhesively secured together as the strips are tightly wound onto the forming reel.

Where the structure to be formed is a pallet of the type described in Figures 7 to 9 of the above-identified Patent Applications, a multiplicity of mandrel means are provided to define the shaped openings in the pallet structure, and control means are provided to introduce the mandrels between the strips and the forming reel in a timed manner as the strips are wound onto the reel to thereby form a pallet structure having the requisite shaped openings.

Brief Description of the Drawings Figure 1 is a plan view of a pallet formed by an apparatus and method embodying the invention; Figure 2 is a side elevation of the pallet of Figure 1; Figure 3 is a schematic plan view of a pallet forming apparatus embodying the invention and capable of performing the method of the invention; Figure 4 is a fragmentary elevation of part of the apparatus of Figure 3 taken along the line 4-4 in Figure 3; Figure 5 is a fragmentary elevation of a second part of the apparatus of Figure 3 taken along the line 5-5 in Figure 3; Figure 6 is a sectional end elevation taken along the line 6-6 in Figure Figure 7 is an end elevation of a third part of the apparatus of Figure 3 taken along the line 7-7 in Figure 3; Figure 8 is a detailed sectional elevation of the clamping strip shown in Figure 7 taken along the line 8-8 in Figure 7; Figures 9a to 9g are schematic sectional end elevations taken along the line 9-9 in Figure 3 showing the use of the mandrels 59 to form the pallets P; and WO 96/38291 PCT/AU96/00325 3 Figure 10 is an end elevation taken along the line 10-10 in Figure 7 showing the positioning of the mandrels 59 in the winding reel flange 52.

Description of Preferred Embodiment Referring firstly to Figures 1 and 2 of the drawings, a presently preferred configuration for the pallet formed by the apparatus embodying the invention is shown. The pallet P is formed from a continuous strip of single-face corrugated board B wound in multiple layers to define a continuous supporting element P defining a central square opening P 2 which may alternatively be round, a pair of opposed generally triangular openings P 3 P4, a pair of opposed truncated triangular openings P 5 P6 at 900 to the triangular openings P 3

P

4 a further pair of larger truncated triangular openings P 7 P8, located at 450 to the preceding pair, a further pair of slightly larger truncated triangular openings P 9

P

1 0 at 900 to the preceding pair, two further opposed pairs of larger truncated triangular openings P 12

PI,

P

14 at 450 to each of the preceding openings P 9 P10, and triangular openings P, 5

P,

1 P7 and at the corners of the pallet defined by the square peripheral element P, of wound single-face corrugated board B.

The triangular and truncated triangular openings in the pallet P are present for the purpose of generating a final pallet shape which is substantially square, and for providing cross beam members which are at a 450 angle to the principal direction of support by the lifting forks between the feet described below. These beam members provide the resistance to bending of the pallet when the pallet is lifted by forks carrying a load. The arrangement of openings reduces the amount of corrugated board B used to form the pallet while ensuring that the resistance to bending of the pallet will be satisfactorily met by the beam members.

The pallet P is provided with three elongate generally rectangular feet F 1

F

2 and F 3 which comprise wound single-face corrugated board B defining an open rectangular loop of the configuration shown in Figures 1 and 2. If desired, the edges of the feet which are to contact a support surface may be treated to prevent damage by moisture. For example, the edges may be dipped in water-proofing wax or may have thin particle board laminated to their lowermost faces. The provision of separate feet which are adhesively secured to the lower face of the pallet is a WO 96/38291 PCT/AU96/00325 4 preferred method of providing fork access for the pallet since the provision of slots in the pallet structure may undesirably weaken the structure.

Referring now to Figures 3 to 7 of the drawings, and in particular Figure 3, the apparatus embodying the invention comprises means 1 for supporting a roll R of single-face corrugated board B, tensioning means 2 for tensioning the corrugated board B as it is paid out from the roll R, slitting and advancing means 3 for converting the corrugated board B into a multiplicity of parallel narrow strips S, adhesive applying means 4 positioned to apply adhesive to the corrugated side of the strips S, a forming reel 5 to which the strips are secured to facilitate winding of the strips into shaped structures, reciprocating mandrel means 53, 59 for defining shaped openings in the structure as the strips S are wound on the reel 5, and severing means 7 for initially trimming the leading edge of the strips S and for severing the strips S when the winding operation is completed.

As shown most clearly in Figures 3 and 4, the roll supporting means 1 comprises a shaft 10 which passes through the roll R and engages at either end, supporting cradles 12, on a frame 14, so that the roll R is freely rotatably supported.

The tensioning means 2 comprises a driven roller 21 having a friction surface 22 about which the board B passes, an idler roller 24, and a support roller 26, which are rotatably mounted on the frame 14, the roller 26 being positioned to guide the board B horizontally between guide rollers 28 towards the slitting and advancing means 3. The rollers 21, 24 and 26 are suitably rotatably mounted on the frame 14 as shown.

The slitting and advancing means 3 comprises a driven slitting roller having a multiplicity of spaced radially extending parallel slitting blades 31 which, in the present embodiment, are spaced to slit the corrugated board B into six narrow strips S of equal width. A trimming blade 32 is positioned adjacent the slitting roller 30 and operates to initially trim the board B along a line perpendicular to the line of slitting before the advancing means is operated, and for severing the strips S when the winding operation has been completed.

Referring to Figures 5 and 6, the advancing means comprises a cross-bar 33 WO 96/38291 PCT/AU96/00325 mounted for reciprocating movement on guide rods 34 mounted at either side of the apparatus, the cross-bar 33 supporting six pneumatic clamps 35 which operate to clamp each strip S to the cross-bar 33 which is driven along the guide rods 34 by a chain drive mechanism 35 to facilitate advancing of the strips S from their starting position to an operative position on the winding reel 5. The strips S are secured to the winding reel 5, in a manner to be described further below, and the advancing means 3 is allowed to return to its rest position prior to the winding operation commencing.

Referring to Figure 5, the adhesive applicator 4 comprises a driven applicator roller 40 arranged over a trough 41 containing adhesive A so that the surface of the roller 40 contacts the adhesive in the trough 41. The strips S are held in contact with the applicator roller 40 by a roller 43 on arms 44 pivoted to the frame 45 of the machine and the required quantity of adhesive is transferred to the corrugated side of the strips as the strips are wound onto the reel 5 in the manner to be described below. A hot melt adhesive applicator 46 is mounted on the frame 44 over the strips S and operates to apply hot melt adhesive to the upper surface of the strips S as the winding operation nears completion so that the outermost layers of the strips S are more positively adhesively secured to prevent unwinding.

Referring to Figures 7 and 8, the winding reel 5 comprises parallel flanges 51, 52, between which the strips are wound as described further below. A central square mandrel 53 passes through a central opening in the flange 52 under the control of a pneumatic cylinder 54, and includes a clamping strip 55 (Figure 8) under which the leading edges of the strips S are clamped at the commencement of the winding operation. The flange 51 is rotatably driven by a chain drive mechanism 56 via a drive shaft 57 driven by a motor 58, the speed of which is controlled by a central programmed controller C.

The flange 52 also carries a further series of pneumatically operated mandrels 593 to 5918 (corresponding to openings P 3 to P 18 arranged at spaced positions from the central mandrel 53 on a supporting frame 60 so as to define the openings in the pallet described in greater detail above. Each mandrel 593 to 59,, is advanced through a shaped opening (Figure 10) in the flange 52 into the space WO 96/38291 PCT/AU96/00325 6 between the flanges 51 and 52 by corresponding pneumatic cylinders 611 to 6118 under the control of the controller C which ensures that the mandrels 593 to 5918 are advanced at the appropriate time during the winding operation.

The apparatus embodying the invention operates in an essentially automatic manner under the control of the central controller C and is able to form six lightweight pallets in approximately 5.5 minutes. It is envisaged that as many as strips S could be cut from a wider roll R of board B thereby further increasing the output of the apparatus.

In use, a roll R of single-face corrugated board is mounted on the shaft which is then engaged with the cradles 12 for free rotation with respect to the frame 14. A length of board B is unwound and fed around the tensioning roller 22, behind the idler roller 24 and over the support roller 26 and between guide rollers 28 until the leading end of the board B reaches the slitting roller 30. The slitting roller 30 is rotated to feed the board through the apparatus to a position in which the leading end is adjacent the trimming blade 32 and the end is trimmed square, whereupon the strips S are advanced to a position over the cross-bar 33 and under the pneumatic clamps 35 which are operated to clamp the strips S to the cross-bar 33. The central mandrel 53 is positioned between the flanges 51 and 52 and the advancing means is actuated to position the leading ends of the strips S adjacent the clamping strip 55 on the mandrel 53 and the ends of the strips S are clamped to the central mandrel 53 and the winding operation commences.

As the strips S run over the applicator roller 40, an appropriate quantity of adhesive is transferred to the corrugated medium of the board B and as the strips S are tightly wound by the winding reel 5, under the tension supplied by the tensioning roller 22, adjacent layers of the strips S are adhesively secured to each other. The mandrels 593 to 59,8 are advanced into the space between the parallel flanges 51 and 52 at the appropriate times in the winding cycle to thereby form the shaped openings in the pallet structure described above, and this is illustrated in Figures 9a to 9g. Near the end of the winding cycle, hot melt adhesive is applied by the hot melt applicator 42 to the top surface of the strips S which are thereby adhesively secured to prevent unwinding when the winding operation is complete.

WO 96/38291 PCT/AU96/00325 7 After the winding operation has been completed, the mandrels 593 to 59,s are withdrawn and the pallet structures P are pushed from the space between the flanges 51 and 52 by a pushing mechanism (not shown) and are carried by a roller conveyor 62 to a removal position.

A separate winding reel 63, similar to the winding reel 5, but having only a single elongate rectangular mandrel 64 is used to form the feet F, to F 3 of the pallet described above, and the feet F, to F 3 are subsequently adhesively secured in the manner shown to the pallet structure P. To ensure the proper adhesive bonding of the feet F after winding, the feet F can be clamped under pressure for a predetermined time after formation with the mandrel still in position.

If desired, the feet can be formed in some other way or from some other material, although the use of corrugated board is convenient for recycling purposes.

The need to form feet may be avoided by forming the pallet structure from wider strips S of corrugated board and forming lifting fork slots or grooves in one face of the pallet structure. This method of forming fork openings is not preferred since the addition of legs of the type described above provides further strength to the finished pallet structure.

Claims

1. An apparatus for forming a pallet from a tightly wound strip of paper, cardboard or corrugated board, comprising means for supporting a roll of paper, cardboard or corrugated board, means for tensioning said paper, cardboard or corrugated board as it leaves said roll, means for advancing said paper, cardboard or corrugated board from said roll to a forming reel, means for applying adhesive to at least one side of said paper, cardboard or corrugated board, means for attaching the free end of said paper, cardboard or corrugated board to said reel to enable the paper, cardboard or corrugated board to be wound onto the reel, mandrel means carried by the winding reel, means associated with each mandrel means for advancing each mandrel means into the path of the strip as it is wound onto said reel for forming adjacent shaped openings in the tightly wound strip of paper, cardboard or corrugated board to form the pallet, control means for controlling the timing of advancement of each mandrel so as to form adjacent shaped openings in the pallet, and means associated with each mandrel means for withdrawing said mandrel means from said reel and said pallet to facilitate removal of the pallet from the reel.

2. The apparatus of claim 1, further comprising a slitting means positioned ahead of the advancing means for slitting the paper, cardboard or corrugated board into a multiplicity of narrow strips to form a corresponding multiplicity of pallets.

3. The apparatus of claim 1 or 2, wherein said corrugated board is single-face corrugated board and the adhesive applying means applies adhesive to the corrugated medium of the board.

4. The apparatus of claim 1, 2 or 3, further comprising means for applying quick setting adhesive to the upper face of the paper, cardboard or corrugated board near the end of the winding operation. The apparatus of any preceding claim wherein said advancing and withdrawing means comprise pneumatic cylinders carrying said mandrels and supported by a frame arranged to rotate with said winding reel.

AMENUED SHEET PFA/AU

6. A method of forming a lightweight pallet comprising the steps of supporting a roll of said paper, cardboard or corrugated board, tensioning said paper, cardboard or corrugated board as it leaves said roll, advancing said paper, cardboard or corrugated board from said roll to a forming reel., applying adhesive to at least one side of said paper, cardboard or corrugated board, attaching the free end of said paper, cardboard or corrugated board to said reel to enable the paper, cardboard or corrugated board to be wound onto the reel, continuously winding said strip of paper, cardboard or corrugated board around a central mandrel carried by said reel to define a central opening, introducing other shaped mandrels carried by said reel between the paper, cardboard or corrugated board already wound and the paper, cardboard or corrugated board being wound to create a multiplicity of shaped openings, winding an outer layer of paper, cardboard or corrugated board to give the pallet its final shape, withdrawing said other shaped mandrels when the winding operation is complete, and severing said paper, cardboard or corrugated board when the wound structure is complete.

7. The method of claim 6, further comprising the step of •applying quick setting adhesive to the upper face of said paper, cardboard or corrugated board near the end of the winding operation.

The method of claim 6 or 7, further comprising the steps of withdrawing said 25 other shaped mandrels when the winding operation is complete, and removing the "pallet from the reel.

9. The method of claim 6, 7 or 8, substantially as hereinbefore described. An apparatus for forming lightweight pallets substantially as hereinbefore described with reference to the accompanying drawings.

TNB:JL:#27107rsl 30 November 1998

11. A pallet when formed by the apparatus of any one of claims 1 to 5 or 10, or by the method of any one of claims 6 to 9. DATED: 30 November, 1998 CARTER SMITH BEADLE Patent Attorneys for the application: VISY BOARD PROPERTIES PTY LTD e* V TNB:JL:#27107rsl 30 November 1998