| 摘要 |
1,232,314. Moulding seals. FORD MOTOR CO. Ltd. 20 Sept., 1968 [29 Sept., 1967], No. 44790/68. Heading B5A. [Also in Division F2] In the moulding of an annular shaft seal comprising an operative seal facing of a material e.g. silicone or fluorosilicone rubber, having superior properties to a seal body material e.g. an epichlorohydrin or polyacrylate resin, or a butadiene, chloroprene, nitrile-butadiene, nitrilechloroprene or styrene butadiene rubber, a disc blank 30 of the body material and a surrounding annular blank 32 of the facing material are placed between the top of the core 10 and die 16 of a mould assembly which has been heated e.g. to 300‹ F., and in which is located the metal casing 28 of the seal. In the Fig. 2 embodiment, the upper die 16 is then moved towards the core 10 and a boss 26 thereon initially contacts the blank 30 to displace material thereof, enclosed by material of the blank 32, over the lip 29 of the core 10. Continued closing of the die 16 until a bottom ridge 26 thereon contacts the casing 28 produces a seal, Fig. 3 (not shown), the interior and exterior vertically extending surfaces whereof comprise the facing material enclosing the body material. A garter spring is subsequently assembled within a groove defined by a projection (24), Fig. 1 (not shown), of die 16. Alternatively, Figs. 4-6 (not shown), a seal comprising only the interior vertically extending surface thereof of facing material may similarly be moulded by covering both a first body disc blank and the surrounding annular blank of facing material with a further disc blank of a body material; where each of these blanks is of different material the interior and exterior vertically extending surfaces of the seal respectively comprise material of the annular blank and of the further disc blank encasing a body of the first disc blank. To improve the bonding of the body and facing materials, each blank thereof may include a proportion of the material of the other. The disc and outer annular blank may be cut from a composite extrusion thereof. Alternatively, the seal may be moulded in an inverted mould assembly wherein the blanks are located within the lower die member 16, the boss 26 being located on the core 10 or in the die 16. |
