APPARATUS FOR FORMING HIGH-IMPACT TRANSPARENT, DISTORTION-FREE POLYMERIC MATERIALS
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Accused Products
Abstract
A method and apparatus are provided for forming a sheet of polymeric material, such as polycarbonate. A forming mold is provided having halves that engage for forming a heated sheet therebetween. Each of the halves defines an interior cavity having a peripheral edge. The sheet is retained between the peripheral edges of the halves and a vacuum is generated within one of the cavities for drawing the sheet therein, whereby a sensing mechanism detects a draw depth for initiating a cooling mechanism to cool the sheet to a temperature below a glass transition temperature of the material. A series of retention mechanisms are provided about the peripheral edge of one of the halves, for biasing the sheet into engagement with the peripheral edge of the opposing half. A trimming mechanism is further provided for trimming the perimeter of the sheet to a desired form.
34 Citations
61 Claims
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1-38. -38. (canceled)
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39. A forming apparatus for forming a sheet of polymeric material, said forming apparatus comprising:
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a first mold half having a bottom wall and a first side wall defining a first interior space said first side wall having a first edge, said first edge having a desired contour or curve for forming a complementary contour or curve in the polymeric material;
a second mold half having a second edge having a complementary contour or curve with said first edge, wherein said first and second halves selectively clamp the sheet between said first and second edges for forming the sheet therebetween, whereby the sheet is moved by pressure into one of said first and second mold halves;
a cooling mechanism disposed within one of said first and second mold haves; and
a sensing mechanism attached to one of said first and second halves for sensing a size of the sheet within one of said first and second mold halves. - View Dependent Claims (40, 42, 43, 44, 45, 46, 47, 48)
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49. A forming apparatus for forming a sheet of polymeric material, said forming apparatus comprising:
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a first half defining a first interior cavity and a first peripheral outer edge;
a second half defining a second peripheral outer edge;
wherein said first and second halves selectively clamp the sheet therebetween and a pressure is generated within one of said first and second mold halves for moving the sheet therein; and
a cooling mechanism operatively disposed within one of said first and second mold halves for cooling the sheet from a first temperature upon sufficient moving of the sheet into one of said first and second mold halves. - View Dependent Claims (50, 51, 52, 53, 54, 55, 56, 57)
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58. A forming apparatus for forming a sheet of polymeric material, said forming apparatus comprising:
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a first mold half defining a first interior space having a first edge;
a second mold half defining a second edge;
a cooling mechanism disposed within one of said first and second mold halves;
wherein said first and second mold halves come together to selectively clamp the sheet therebetween, whereby the sheet is solely supported by one of the first and second edges throughout a forming process. - View Dependent Claims (41, 59, 60, 61)
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Specification