Abstract:
The invention relates to a method and anapparatus for deep-drawing a tray(1) froma blank ofsheet material(2).The blank is provided with score lines, which determine the location of wrinkles formed in the process.The apparatuscomprises a female moulding tool(3), which comprises a cavity(7)for forming the tray bot- tom outwardly,a male moulding tool(4), which comprises a plunger(11)for form- ing the tray bottom inwardly, the plunger being movable with respect to the cavity for forming the tray, andclamps(6, 15)with an interface for holding the sheet ma- terial and forming a tray rim flange. According to the inventionby laterally distanc- ingat least one ofthe moulding tools (3, 4) from the sheet material leeway is pro- vided for free forming so that wrinklingof the tray side wallsis achieved in a con- trolled manner.Spacer plates (13) may be positioned behind the plunger (11), to adjust its position in relation to thecavity (7) of thefemale moulding tool (3). The cavity may have a separate bottom plate(8)and spacer plates(9)therebelow, or screw means may be provided foradjusting the distance ofthe bottom of the cavi- ty fromthe clamp interfaceand thereby varying the depth of the tray.
Abstract:
The invention relates to a method and an apparatus for deep-drawing a tray (1) from a blank of sheet material (2). The blank is provided with score lines, which determine the location of wrinkles formed in the process. The apparatus comprises a female moulding tool (3), which comprises a cavity (7) for forming the tray bot-tom outwardly, a male moulding tool (4), which comprises a plunger (11) for form-ing the tray bottom inwardly, the plunger being movable with respect to the cavity for forming the tray, and clamps (6, 15) with an interface for holding the sheet ma-terial and forming a tray rim flange. According to the invention by laterally distanc-ing at least one of the moulding tools (3, 4) from the sheet material leeway is pro-vided for free forming so that wrinkling of the tray side walls is achieved in a con-trolled manner. Spacer plates (13) may be positioned behind the plunger (11), to adjust its position in relation to the cavity (7) of the female moulding tool (3). The cavity may have a separate bottom plate (8) and spacer plates (9) therebelow, or screw means may be provided for adjusting the distance of the bottom of the cavi-ty from the clamp interface and thereby varying the depth of the tray.