GB862533A - Improvements in the making of relief maps - Google Patents

Abstract

862,533. Vacuum-moulding resinous sheet materials. SOC. RICO N. C. April 10, 1959 [April 12, 1958], No. 12272/59. Class 87(2). A curved relief map is produced by applying written matter and/or design to a flat sheet of plastic material, e.g. polyvinyl chloride of uniform thickness, placing the sheet in a bent condition approximating the curvature of the map adjacent a negative mould of the relief map, heating the sheet and drawing it on to the mould by a deep-draw vacuum technique, and then allowing the moulded sheet to cool. A hollow box 2 mounted on a frame 1, is closed at the top by a curved negative relief mould 3 of one quarter of the surface of the terrestrial globe. A curved transparent sheet 7 of polyvinyl chloride with printing on its upper side and held by a frame 6, is softened by heaters 10, the mould 3 raised to contact the sheet, and suction applied via pipe 5 and perforations 4 to draw the sheet 7 on to the mould 3. The three other quarter surfaces of the globe are similarly moulded and the four moulded sheets are applied to an oblate support. Alternatively the four quarter surfaces may be moulded simultaneously in one apparatus.