(under subclass 90) Subject matter wherein the housing or casing containing the inductor contains an insulating fluid in which the inductor is immersed.
(1) Note. If means are provided for circulating the insulating fluid, for cooling purposes, the patent is not classified herein but rather in subclass 57.
(2) Note. If the insulating fluid comprises a liquid and is provided for a cooling effect, classification is not herein but rather in subclass 58.
(3) Note. For the locus of patents to insulating fluids, per se, see the search notes in subclass 58.
