Casting methods for encapsulating electrical conductors

Claim 2

A process for substantially continuously casting a resinous insulating system to at least partially encapsulate electrically conductive means, comprising the steps of: providing a first vacuum system, providing a second vacuum system having a predetermined level of vacuum therein, providing a rotatable carriage having a plurality of vacuum chambers, and a plurality of index positions, loading a mold containing the electrically conductive means to be encapsulated into each vacuum chamber while the vacuum chamber is at atmospheric pressure, individually evacuating each vacuum chamber at one of the indexing positions with the first vacuum system, following the loading step, providing a level of vacuum which will enable each vacuum chamber to enter the second vacuum system without substantially affecting the level of vacuum in the second vacuum system, transferring each vacuum chamber to the second vacuum system, following the step of evacuating each vacuum chamber, indexing each vacuum chamber through a plurality of index positions while connected to the second vacuum system, simultaneously interconnecting the vacuum chambers in these index positions through the second vacuum system, introducing a resin system into the mold disposed in each vacuum chamber at one of the index positions at which the vacuum chamber is connected to the second vacuum system, degassing the resin system after it is introduced into each mold at another of the indexing positions while the vacuum is being maintained in its associated vacuum chamber by the second vacuum system, disconnecting each vacuum chamber from the second vacuum system, following the degassing step, without affecting the level of vacuum in the second vacuum system, returning each vacuum chamber to atmospheric pressure after it has been disconnected from the second vacuum system, and removing the mold and the resin system disposed therein from each vacuum chamber, after each vacuum chamber is returned to atmospheric pressure.

Claim 3

The process of claim 3 wherein the resin system introduced into the vacuum chambers has been prepared by the steps of heating certain of the components of the resin system, introducing the components of the resin system into a mixing chamber, heating the mixing chamber, evacuating the mixing chamber, and mixing the ingredients while the chamber is evacuated.

Claim 4

The process of claim 4 including the step of returning the mixing chamber to atmospheric pressure after mixing to facilitate the introduction of the resin system into the evacuated vacuum chamber.