| 摘要 |
<p>1490951 Moulding protective layer on electrical components SIEMENS AG 5 Jan 1976 [31 Jan 1975] 00152/76 Heading B5A An electrical component, e.g. a relay 1, having a base 1b with connection pins 2 and a dust cap 1a forming an enclosure with the base, has a protective layer 5 heat shrunk on to the base and extending to embrace the cap with the pins projecting through holes 5b in the layer 5, an adhesive 6 being used between the layer 5 and the cap and base which melts during heat shrinking. An injection moulded protective layer 5 of cross-linked polyolefin which has been stretched a larger amount around the sides 5c than around the holes 5b is given a coating of adhesive 6 which covers the holes. The layer 5 may have more holes than there are pins 2 so that one standard shape can be used for different pin arrangements. The holes where there are no pins remain sealed with adhesive. Five quartz glass jaws 7 press the layer 5 on to the component 1, the lowermost 7a having holes 9 to accommodate the pins 2. The layer 5 is coloured black and is heated by infra-red radiation passing through the jaws 7 from sources 8. Alternatively heated jaws or hot air may be used.</p> |
