GB1375597A - - Google Patents

Abstract

1375597 Bending sheet material J I GATES 5 May 1972 [21 May 1971] 31005/73 Divided out of 1375596 Heading B6J A method of bending an elongate thermoplastics element comprises positioning a portion of the element between two dies, heating the element, relatively moving the dies during continued heating, and then cooling the element. The element 12 is bent between dies 105, 142, the surfaces of the dies each being complementary to the abutting surface of the element 12 so that the element is bent without distortion of its cross-section. The element and flexible die 142 are first clamped at one end between a backup block 182 and pad 186 by clamp 181 and are engaged along their lengths. A bending assembly 140 (Figs. 11, 14) is then engaged with spindle 139 of the fixed die, the assembly having a roller 200 spring biased against the back of flexible die 142. Steam is then supplied through ducts 132, (154) to cavities 110, 150 in the dies and passes through passages 215, 151, 153 to or towards the element 12. The bending assembly 140 is then tuned by handle 213 about spindle 139 until element 12 and die 142 have reached the dotted line position of Fig. 12. A pin is then inserted in hole 188, and air is supplied to the dies to cool the element. The element is then removed. A strip may be bent into a loop around successive dies (Fig. 21) which are then moved inwardly to allow removal of the strip.