METHOD AND APPARATUS FOR THE FABRICATION OF 3-DIMENSIONAL BLANKS

Abstract: The invention relates to a method and apparatus for fabrication of 3-dimensional blanks (136) for encasing articles, particular chocolate novelties. The apparatus uses a first pressing station (5) for subdividing a sheet (42) into multiple moulds (62) and a second station (54) for forming final moulds coinciding with the multiple moulds (62). The stations (50, 54) have clamping members (84, 84B) for ensuring accurate registration of the moulds.

Description: MEIHOD AMD APPARATUS FOR THE FABRICATION OF S-DIMENSIONAL BLANKS The present invention relates to a method and apparatus for the fabrication of 3-dimensional blanks for the packaging of articles and is particularly, although not exclusively, directed to a method and apparatus for fabrication of 3-dimensional blanks for the moulding of foil encased articles. In the prior art hollow chocolate eggs, rabbits and other novelties are made using 3-dimensional foil blanks. These blanks are cut into sheets when formed and contain a plurality of moulds. These moulds are usually located transverse to the longitudinal direction of the conveying direction and may contain two rows of moulds. The shaped blanks form one half of a mould for producing the hollow novelties. Each mould is formed by a pressing operation where a continuous length of foil passes through male and female dies. The shape of the dies is impressed into the foil to achieve each 3-dimensional mould shape. Once pressed the dies are opened and the foil advanced to shape the next mould. The foil is then cut to size e.g. 5 moulds per sheet. Each sheet is placed in a spinning frame mated with a corresponding sheet and chocolate inserted. When spun the chocolate inside the co-operating moulds will form a hollow article encased in foil. The problems with the prior art are numerous. As a single press operation is used only one type of shaped mould can be fabricated in a production run. If the foil tears the production line is halted with significant down time and wastage of the foil. As the foil is preprinted this can be an expensive exercise. The stamping procedure is very slow and prone to pinholing of the formed blank. Alignment of the preprinted foil with the shape forming moulds is not exact with this process and can result in slight drifting of the patterns. It is an object of the present invention to alleviate the abovementioned problems to produce a more consistent blank. A further object of the present invention is to provide an increase in the speed of production of the blanks over the prior art. A still further object of the invention is to provide a method and machine for forming multiple blanks at a pressing station. With these objects in view the present invention in one aspect provides a method for producing 3-dimensional blanks containing a plurality of moulds impressed in a sheet material, said method including the steps oi (i) clamping said sheet; (ii) forming a first plurality of mould impressions in said clamped sheet at a first station to subdivide said sheet; (iϊi) moving said subdivided sheet to a second station; (iv) clamping said subdivided sheet at said second station; (v) forming at least one set of final mould impressions coinciding with said first plurality of mould impressions. In* a further aspect of the invention there is provided an apparatus for producing 3-dimensional blanks containing a plurality of moulds impressed in a sheet material, said apparatus including a plurality of sequentially arranged stations for forming said moulds; a first station including sheet clamping means and means for subdividing said sheet into a plurality of first mould impressions; a second station including sheet clamping means and a pair of co-operating complementary dies for forming final mould impressions coinciding with said plurality of first mould impressions. The above and other objects, features and advantages of the present invention will become apparent from the ensuing detailed description of preferred embodiments thereof, which is to be considered in conjunction with the accompanying drawings, in which:- Fig. 1 is a side view of a first embodiment of machine for the fabrication of 3-dimensional blanks made in accordance with the invention; Fig. 2 is a plan view of the machine shown in Fig. 1 with the stations removed from the machine; Fig. 3 is a cross-sectional view along and in the direction of arrows 3-3 of Fig. 1 of a first station for subdividing a sheet with a first set of mould impressions; Fig. 4 is a similar view to that of Fig. 3 showing the station in its closed position; Fig. 5 is a cross-sectional view along and in the direction of arrows 5-5 of Fig. 4; Fig. 6 is a perspective view of the blank as formed at the first station; Fig. 7 is a cross-sectional view along and in the direction of arrows 7-7 of Fig. 1 of a second station for further subdividing a sheet with a second set of mould impressions; Fig. 8 is a cross-sectional view along and in the direction of arrows 8-8 of Fig. 7 of the second station; Fig. 9 is a cross-sectional view along and in the direction of arrows 9-9 Fig. 8 of the second station; Fig. 10 is a perspective view of the blank as formed at the second station; Fig. 11 is a cross-sectional view along and in the direction of arrows 11-11 of Fig. 2 of a third station; Fig. 12 is a similar view to that of Fig. 11 showing the third station in its closed position; Fig. 13 is a cross-sectional view along and in the direction of arrows 13-13 of Fig. 12 of the third station; Fig. 14 is a cross-sectional view along and in the direction of arrows 14-14 of Fig. 2 of a fourth station; Fig. 15 is a cross-sectional view along and in the direction of arrows 15-15 of Fig. 2 of a fifth station; Fig. 16 is a view similar to Fig. 3 showing an alternative embodiment for the operation of the various stations shown in Figs. 1 to 15; Fig. 17 is a similar view to that of Fig. 6 showing a variation of the mould shape; and Hg. 18 is the final blank fabricated by the machine shown in Figs 1 to 16 using the blank in Fig. 17. Turning to Figs. 1 to 15 there is shown a machine 20 for forming 3-dimensional blanks from a sheet material. The machine includes two offset endless chain conveyors 22, 24 which are driven by sprockets 26 through motors (not shown). The conveyors are controlled by a controller (not shown) to move the chains in an intermittent manner through the various stations to be described. A plurality of trays 28 are pivotally attached at diagonal corners 30, 32 to conveyors 22, 24 to provide horizontal movement of trays 28. The offset nature of conveyors 22, 24 will always maintain trays 28 in the horizontal disposition. In the embodiment illustrated each tray 28 is subdivided into two smaller trays 34, 36 to provide a dual in-line fabrication machine. It is dear that a single tray or multiple tray system can be used depending on requirements. Each tray 34, 36 is basically formed as a peripheral rectangular frame of L-shaped cross-section. A lower ledge 38 (Rg. 3) supports a template 40 to form the base of trays 34, 36. The machine 20 requires sheets 42 of material for placing in trays 34, 36. These sheets are usually formed from a preprinted aluminium foil. Such foils can indude other material or be incorporated in a laminate. Preferred materials to be used indude aluminium foil with a food grade varnish and a three layer laminate comprising an outer layer of polypropylene, a middle layer of aluminium foil and an inner layer of polyethylene. The sheets 42 can be provided in a stad (not shown) or can be cut by the machine. In the embodiment illustrated a roll 44 of sheet material is run over rollers 46 to straighten the material and is then cut to length by a cutter 48. The cut sheets 42 are placed in trays 34, 36 for mould impressing. The sheets are thai transported sequentially through the machine through six stations 50, 52, 54, 56 58 and 60. Station 50 provides an initial subdivision of sheet 42 into preliminary moulds as shown in Fig. 6. Fig. 6 shows that sheet 42 has been formed into three longitudinal moulds 62 by station 50. It is to be noted that the number of moulds can vary depending on requirements. Station 50 indudes an outer support frame 64 from which depends a stationary box frame 66 having a divider 68 intermediate its length. Secured to divider 68 is a biasing means 70, preferably pneumatically controlled or spring tensioned, with a piston rod 72 passing through an aperture in divider 68. In an especially preferred embodiment biasing means 70 is an air spring. Piston rod 72 is attached to a plate member 74 having two longitudinal parallel depending dividers 76, 78. Each divider 76, 78 terminates in a roller 80. Dividers 76, 78 form a telescopic relationship with box frame 66. Centrally located along plate member 74 is a pair of parallel flanges 82 which constrain a longitudinal clamping member 84. Clamping member is spring loaded by springs 86 and terminates with a bumper 88. The movable part of station 50 comprises a base member 90 on which are mounted male moulds 92. The moulds 92 are separated by gaps 94 which gaps are aligned with dividers 76, 78. Base member 90 is attached to a redprocating piston 96. Moulds 92 can, in use, protrude through apertures 98 of template 40. In operation, the initial position is shown in Fig. 3. Moulds 92 are moved upwardly by piston 96 through template 40 to contact sheet 42. Further upward movement of piston 96 raises sheet 42 as moulds 92 protrude through the template until template 40 rests on base member 90. Sheet 42 will contact bumper 88 to damp sheet 42 to the central mould. As clamping member 84 is spring loaded a continuous clamping pressure will be maintained preventing any slippage of sheet 42. Further movement results in dividers 76, 78 entering gaps 94 to draw sheet 42 inwardly between the gaps and form the central mould. Rollers 80 will assist in preventing any nipping or tearing of sheet 42. Sheet 42 will be simultaneously drawn over the outermost moulds 92. Rollers 80 will abut template 40 and form a flattened area which subdivides the moulds formed in the sheet. Further upward movement of piston 96 forces the free ends of box frame 66 to contact template 40 to finalize the moulding of sheet 42. This position is shown in Fig. 4. Fig. 4 shows that male moulds 92 have impressed into sheet 42 the mould shapes shown in Hg. 6. It will be noted that the height of the moulds 62 formed in sheet 42 can be varied by changing the thickness of template 40. The formation of moulds 62 is from the centre and outwardly therefrom in opposing directions. This results in less stress being applied to sheet 42 and a uniform 'movement of the sheet over moulds 92. Once moulds 62 have been formed the procedure is reversed. Tray 28 is then moved to station 52. Station 52 is very similar to station 50 and similar integers have been referenced with the same reference numerals and an "A" suffix. The differences are that male moulds 92 have been subdivided transversely to form fifteen (15) male moulds 92A i.e. a grid of 5 x 3. Again it must be emphasized that the grid can be increased or decreased depending on requirements. From Figs. 7 and 8 it is shown that dividers 76A, 78A are transverse to the direction of dividers 76, 78 of station 50. To provide the increase in subdivision, further dividers 100, 102 depend from plate member 104. Plate member 104 is supported by two biasing means 106, 108 similar to biasing means 70 of station 50. Fig. 8 dearly shows the telescopic nature of the dividers 76A, 78A, 100, 102 with box frame 66A. As with station 50 the further dividers 100, 102 terminate with rollers 110. Winglets 112 are attached to the free ends of box frame 66A and dividers 76A, 78A, 100, 102 and are aligned with the longitudinal gaps formed between moulds 62 shown in Fig. 6. The winglets will assist in location and guidance of the dividers in further subdivision of sheet 42. Operation of station 52 is identical to that described in relation to station 50. Again, the telescopic nature of the dividers allows for a smooth sequential subdivision of moulds 62 into the moulds 114 as shown in Hg. 10. The moulds 114 are formed from the centre and outwardly therefrom in opposing directions. The further subdivided sheet 42 is passed through to station 54. Station 54 is very similar to stations 50 and 52 and similar reference numerals have been used for similar integers with the suffix "B". The differences between station 52 and station 54 are that male moulds 92B are shaped with almost the final desired shape. Dividers 76A, 78A, 100 and 102 have been replaced by the female moulds 116 and clamping member 88A has been replaced by a female mould 118. Additional female moulds 120 are also secured to the inner walls of box frame 66B. As can be seen in Fig. 11 the moulds 116, 118 and 120 are solid and telescopic in nature and operated in a similar manner as the dividers in station 50, 52. Fig. 14 shows the completion of the formation of the almost completed mould shapes. Sheet 42 then moves to station 56. Station 56 impresses the final mould shapes into sheet 42. Similar reference numerals have been used for similar integers with a suffix of "C". As this is the final shaping process female moulds 116, 118 and 120 are replaced by a heated female mould 122. Mould 122 is secured to divider 68C by an insulation heat bank 124. With the applied pressure and heat a stiffening of the sheet will occur. If the sheet is the laminate of polypropylene/aluminium foil/polyethylene the heating will soften the polyethylene to form a series of moulds in sheet 42. Station 58 is optional and is a cutting station. Blades 126 are located in a block 128 and co-operate with a spring loaded pressure pad 130. Blades 126 can be in any desired formation for completely severing sheet 42 into individual moulds. The sheet 42 need not be severed as it can be used directly in a spinning frame. The finished sheet is finally transported to station 60 (Fig. 1) where a suction lifting mechanism 132 removes the formed sheet 42 from trays 28 and places them on a nested stack 134. The invention has many advantages over the prior art. As a plurality of moulds can be pressed simultaneously the moulds can be different. The speed of operation is significantly increased and four-fold increases in production can be expected. The smooth movement of the sheet over the male moulds decreases the rejection rate of moulded sheets and reduces the downtime during production runs. From the foregoing it will be understood that the shaped-foil blanks formed by the method and apparatus of the invention are especially suitable for the production of foil-encased hollow artides such as hollow chocolate eggs or hollow chocolate rabbits or other such hollow chocolate novelties. However, it is also to be understood that said shaped-foil blanks are suitable for the packaging of a wide range of other products such as confectionery for human consumption; ice cream; food industry goods; cosmetics and toiletries; pet products, such as confectionery not for human consumption; garden products; sporting goods; hobbies; automotive products; fashion gift products; hardware products; toys; agricultural products; convenience packs; promotional products such as for pop concerts, sporting events, and the like; souvenirs; and travel goods. In the first embodiment, stations 50, 52, 54, 56 have movable pistons 96, 96A, 96B, 96C for controlling the mould forming operations. Fig. 16 illustrates a second embodiment where box frame 130 reάprocates vertically through a piston-cylinder arrangement 132. Fig. 16 shows the equivalent of station 50 of the first embodiment. The operation of the embodiment shown in Fig. 16 is fairly similar to that previously described and will not be further described. Reference to Figs. 17 and 18 show variations of moulds that can be produced by the present invention. The blank 134 shown in Fig. 17 can be obtained by omitting station 50 and replacing male moulds 92A of station 52 with male moulds similar to those at station 50 but having longitudinal directions transverse to those shown at station 50. At stations 54, 56 the male moulds 92B, 92C will have the shapes shown in blank 136 of Fig. 18. Station 56 may also be omitted if the desired stiffening of the final moulded sheet is not required. It is believed that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts and that changes may be made in the form, constructions and arrangement of the method and apparatus described without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the forms hereinbefore described being merely preferred embodiments thereof.

Claims: The claims defining the invention are as follows:- ' 1. A method for producing 3-dimensional blanks containing a plurality of moulds impressed in a sheet material, said method induding the steps ofi- (i) damping said sheet; (ϋ) forming a first plurality of mould impressions in said damped sheet at a first station to subdivide said sheet; (in) moving said subdivided sheet to a second station; (iv) damping said subdivided sheet at said second station; (v) forming at least one set of final mould impressions coindding with said first plurality of mould impressions. 2. The method of claim 1, wherein said damping of said sheet takes place at the same position. 3. The method of claim 1 or claim 2, wherein said damping is intermediate said sheet and in the subdivision direction. 4. The method of any one of the preceding claims, wherein said mould impressions are sequentially formed commencing from the middle of said sheet and moving in opposing outward directions. 5. The method of any one of the preceding claims, wherein said first plurality of mould impressions are formed in a two stage process, a first stage where the sheet is subdivided in one direction and a second stage where said subdivided sheet is further subdivided in a direction transverse to said one direction. 6. The method of any one of the preceding claims, wherein said at least one final mould impressions are performed in two stages, a first stage where almost final impressions are made and a second stage where the final impressions are made under heat and increased pressure. 7. The method of any one of the preceding claims, wherein said first plurality of mould impressions are formed by the relative movement of a plurality of dividers between a plurality of dies corresponding to the desired shape of the mould impressions to be formed. 8. The method of any one of the preceding claims, wherein said final mould impressions are formed by the relative movement of a plurality of complementary opposing dies. 9. An apparatus for producing 3-dimensional blanks containing a plurality of moulds impressed in a sheet material, said apparatus induding a plurality of sequentially arranged stations for forming said moulds; a first station induding sheet damping means and means for subdividing said sheet into a plurality of first mould impressions; a second station induding sheet clamping means and a pair of co-operating complementary dies for forming final mould impressions coindding with said plurality of first mould impressions. 10. The apparatus of claim 9, wherein said sheet clamping means of said first station indudes an elongated member located intermediate said sheet and parallel to the subdivision direction. 11. The apparatus of claim 9 or claim 10, wherein said means for subdividing said sheet indudes pairs of parallel dividers which draw said sheet over corresponding moulds to subdivide said sheet. 12. The apparatus of claim 11, wherein said pairs of parallel dividers are contained one within the other and move sequentially from the innermost to the outermost to form said subdivisions. 13. The apparatus of claim 12, wherein the inner pairs of parallel dividers terminate with rollers. 14. The apparatus of daim 11, wherein said corresponding moulds are located on a planar base member, said sheet is adapted to be located within a tray having a removable template forming the floor of said tray and said template having a plurality of apertures through which said corresponding moulds can protrude. 15. The apparatus of claim 14, wherein said tray forms part of a conveyor system. 16. The apparatus of any one of claims 9 to 15, wherein said sheet clamping means of said second station indudes a pair of co¬ operating complementary dies. 17. The apparatus of claim 16, wherein said pair of co-operating complementary dies comprises a set of male moulds mounted on a base member and a plurality of telescopic female moulds which indudes said sheet clamping means. 18. The apparatus of claim 17, wherein an additional station is located between said first and second stations, said additional station being of similar construction to said first station but subdividing said sheet in parallel directions transverse to said subdivision direction. 19. The apparatus of claim 18, wherein said additional station indudes pairs of parallel dividers which draw said sheet over corresponding moulds to further subdivide said sheet. 20. The apparatus of claim 19, wherein said pairs of parallel dividers of said additional station are contained one within the other and move sequentially from the innermost to the outermost to form said further subdivisions. 21. The apparatus of claim.20, wherein the inner pairs of parallel dividers of said additional station terminate with rollers. 22. The apparatus of any one of claims 19 to 21, wherein the free ends of said parallel dividers have winglets attached thereto in a direction perpendicular to said dividers, said winglets being aligned with the impressions formed by said dividers of said first station to provide alignment of said sheet. 23. The apparatus of any one of claims 9 to 22, wherein a final pressing station is located after said second station, said final pressing station induding complementary male and female dies, said final pressing station applying heat and pressure to finalize the mould shapes impressed in said sheet. 24. An apparatus for producing 3-dimensional blanks substantially as hereinbefore described with reference to the accompanying drawings. 25. A method for producing 3-dimensional blanks substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: BOYHAN LAWRENCE ANTHONY, BOYHAN, LAWRENCE, ANTHONY
Applicants: GRADUAL PTY LTD, GRADUAL PTY. LTD.
Application year: 1990
Main classification: B65B47
IPC codes: B31B43, B65B43