GB1239521A - - Google Patents

Abstract

1,239,521. Moulding seal rings. MICRODOT Inc. 18 June, 1969, No. 30960/69. Heading B5A. An annular elastomeric seal 63 is moulded and bonded to an annular metal support 15 by a die set comprising an upper die insert 35 axially movable relative to a plate 34 secured to a press, a stationary bottom plate 12 with a lower die insert 11 thereon which is recessed to receive the support 15, and a centre die insert 22 with an annular portion 29 which clamps the support during the moulding operation. With the die open, Fig. 1, elastomeric material 59 is placed on a core 18, 21 flanged at 19 and resiliently secured by a bolt 16 and spring washers 17; the core is thus slightly movable relative a replaceable part 14 to allow gases to escape from the die cavity via an annular groove 55 in the part 14 and bores 49, 57. When the pressure plate 34 is lowered a bushing 39 acts on a plate 41 via a spring 42 to force the insert 22 downwardly causing it to position and clamp the support 15 and compress the material 59 and force it into the die cavity formed between the parts 29, 14 and the lower parts 43, 46, Fig. 5, of the insert 35. The parts 43, 46 are so shaped that when the die is opened they tear the surplus elastomeric material from that in the die cavity. During the initial opening movement of the die, the insert 22 is held down by the spring 42.