Encapsulated electrical inductive apparatus

Claim 2

An encapsulated electrical inductive apparatus comprising: an electrical inductive apparatus; a case surrounding said electrical inductive apparatus; an infusible, thermal conductive mixture filling the space between said case and said electrical inductive apparatus; said thermal conductive mixture comprised of at least first and second inert, inorganic, particulate materials cohesively joined by a binder material; the average size of said particles of said first material being substantially larger than the average size of said particles of said second material; said binder material coating said particles of said second material only, so as to cohesively join said particles of said second material to contiguous particles of said first and second materials only at their points of contact such that interstices are formed between the non-contacting portions of said particles of said first and second materials.

Claim 3

The encapsulated electrical inductive apparatus of claim 1 wherein the inert, inorganic particles of the first material are rounded gravel particles having an average size of between about 1/4 inch in diameter to about 1 inch in diameter.

Claim 4

The encapsulated electrical inductive apparatus of claim 1 wherein the inert, inorganic particles of the second material are rounded sand particles of non-uniform size.

Claim 5

The encapsulated electrical inductive apparatus of claim 1 wherein the binder material is a cured resin.

Claim 6

The encapsulated electrical inductive apparatus of claim 4 wherein the binder material is a cured thermosetting resin which forms a coating around each particle of said second material of such thickness that said resin constitutes from about 2 to about 5% of the weight of each coated particle of said second material.

Claim 7

The encapsulated electrical inductive apparatus of claim 1 wherein the thermal conductive mixture is comprised of between about 40 to about 60% by weight of said first material.

Claim 8

The encapsulated electrical inductive apparatus of claim 1 wherein sealant means is provided for the thermal conductive mixture.

Claim 9

The encapsulated electrical inductive apparatus of claim 7 wherein the sealant means consists of finely-divided, inert, inorganic particles cohesively joined together by a cured resin.

Claim 10

The encapsulated electrical inductive apparatus of claim 8 wherein the cured resin material in the sealant means constitutes from about 10 to about 15% by weight of the sealant means whereby all of the interstices between adjoining particles in said sealant means are filled with said resin.

Claim 11

An encapsulated electrical inductive apparatus comprising: an electrical inductive apparatus; a case surrounding said electrical inductive apparatus; an infusible, thermal conductive mixture filling the space between said case and said electrical inductive apparatus; said thermal conductive mixture comprised of at least first and second inert, inorganic, particulate materials cohesively joined by a binder material, wherein said mixture is composed of between about 40 to about 60% of said first material by weight; said first material being rounded gravel particles having an average particle size of between about 1/4 inch to about 1 inch in diameter; said second material being finely-divided, rounded sand particles of non-uniform size; said binder material consisting of a cured thermosetting resin forming a coating around each sand particle of such thickness that said resin constitutes between about 2 to about 5% of the weight of each coated sand particle, said resin coating being sufficient to cohesively join said sand particles to contiguous sand and gravel particles only at their points of contact thereby leaving interstices between the non-touching portions of contiguous sand and gravel particles; a non-porous sealant mixture forming a moisture barrier for said thermal conductive mixture; said sealant mixture consisting of finely-divided, inert, inogranic particles cohesively joined together by a cured resin which constitutes from about 10 to about 15% by weight of said sealant mixture such that all interstices between contiguous particles are completely filled by said resin.

Claim 12

An encapsulated electrical inductive apparatus comprising: an electrical inductive apparatus; a case surrounding said electrical inductive apparatus; an infusible, thermal conductive mixture filling the space between said case and said electrical inductive apparatus; said thermal conductive mixture comprised of at least first and second inert, inorganic, particulate materials cohesively joined by a binder material, wherein said mixture is composed of between about 40 to about 60% of said first material by weight; said first material being rounded gravel particles having an average particle size of between about 1/4 inch to about 1 inch in diameter; said second material being finely-divided, rounded sand particles of non-uniform size; said binder material consisting of a cured thermosetting resin forming a coating around each sand particle of such thickness that said resin constitutes between about 2 to about 5% of the weight of each coated sand particle, said resin coating being sufficient to cohesively join said sand particles to contiguous sand and gravel particles only at their points of contact thereby leaving interstices between the non-touching portions of contiguous sand and gravel particles; a non-porous sealant mixture forming a moisture barrier for said thermal conductive mixture; said sealant mixture consisting of finely-divided, inert, inogranic particles cohesively joined together by a cured resin which constitutes from about 10 to about 15% by weight of said sealant mixture such that all interstices between contiguous particles are completely filled by said resin.

Claim 15

The method of encapsulating an electrical inductive apparatus of claim 11 wherein the steps are performed in the recited order.

Claim 16

The method of encapsulating an electrical inductive apparatus of claim 12 including the additional step of pouring a sealant mixture of powdered resin and finely-divided, inert, inorganic particles, each coated with a "B" stage resin, onto the mixture of the first and second materials after the step of applying vibrations but prior to the step of solidifying the resin.

Claim 17

The method of encapsulating an electrical inductive apparatus of claim 11 including the step of selecting a first material such that all of the inert, inorganic particles have a substantially rounded exterior surface.

Claim 18

The method of encapsulating an electrical inductive apparatus of claim 11 including the step of selecting the second material such that all of the finely-divided, inert, inorganic particles have a substantially rounded exterior surface.

Claim 19

The method of encapsulating an electrical inductive apparatus of claim 11 including the step of selecting the first and second materials such that all of the inert, inorganic particles of said first and second materials have a substantially rounded exterior surface.