US687531A

US687531A - Insulating material.

Info

Publication number: US687531A
Authority: US
Inventors: Charles W Jefferson
Original assignee: Mica Insulator Co
Current assignee: Mica Insulator Co
Priority date: 1901-02-07
Filing date: 1901-02-07
Publication date: 1901-11-26
Anticipated expiration: 1918-11-26

Description

Patented Nov. 26. IQOI.

0. W. JEFFERSON. INSULATING MATERIAL.

(Apgl iqation med Feb. 7, mm.

("0 Model.)

NVENTOR ATTORNEYS WITNESSES UNITED STATES PAT NT OFFICE.

CHARLES W. JEFFERSON, OF SCHENECTADY, NEW YORK, ASSIGNOR TO THE MICA INSULATOR COMPANY, A CORPORATION OF NEIV JERSEY.

INSULATING MATERIAL.

SPECIFICATION forming part of Letters Patent No. 687,531, dated November 26, 1901.

' Application filed February '7, 1901; Serial No. 46,305. (No model.)

To all whom it may concern: Be it known that I, CHARLES W. J EFFER- SON, a subject of the Queen of Great Britain,

and a resident of Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Insulating Material, of which the following is a specification.

My invention relates to compound insulat- :0 ing materials; and it has for its object the manufacture of such a material that will not only be thoroughly flexible, pliable, and nonbrittle, but that will also be able to resist a very high electrical voltage and to withstand a very great degree of heat.

Electrical insulators have been made in the shape of plates or sheets and of some comminuted or pulverized non-combustible insulating material mixed with a hardening 2o cement. One of the disadvantages of this kind of insulator is that it is not pliable and that it is brittle and also that it has not the required efficiency as to insulation and durability, and the plates or sheets. so made being brittle and non-pliable are more apt to chip and break when being manipulated or cutinto smaller pieces for insulation. In order to remedy these defects and to give the sheet more durability and flexibility,sheets of 0 fabric have sometimes been introduced into the combined insulating sheet or plate; but the disadvantage of the use of such fabric is that it is readily carbonized, and as soon as this happens the efficiency of the insulator is 3 5 impaired. Sheets of insulating material have also been made from layers of scales of mica cemented by a varnish and then the sheet so formed dried by steam and then subjected to intense pressure, so that the varnish between the mica scales and between the layers will be expelled, leaving only sufiicient of the varnish to cause the mica scales to adhere together. The plate or sheet so formed is then subjected to intense pressure, so that the 5 different layers of mica scales are formed in to a compact sheet in a hard state. A sheet of insulation constructed as above described makes a very good insulator; but as the sheet itself isvirtually composed of a solid mass of mica it is somewhat brittle and not as pliable as is sometimes desired. Also with such a construction of insulating-sheet it is liable to crack, especially when out into smaller pieces or trimmed. By my invention a very simple, inexpensive, pliable, non-brittle, and highly-efficient insulating material can be constructed.

My invention consists of the insulated material herein described.

In the accompanying drawings, Figure 1 illustrates in perspective a sheet of insulating material showing one embodiment of my invention, said sheet being broken away at different parts to clearly show the construction. Fig. 2 is a fragmentary view, enlarged, in plan and showing how the different scales of mica may be laid and are united. Fig. 3 is a fragmentary cross-section,greatly magnified, of portion of the insulating-sheet illustrated by Fig. 1. Fig. 4c is a similar View to 76 Fig. l, but showing a slightly-modified form of insulated sheet. Fig. 5 illustrates the mechanism which may be used in one stage of the process of making t-heinsnlating-sheet.

Similar numbers represent like parts in all the figures.

1 represents the pliable substance forming the body of my improved insulating-sheet and also arranged in alternate layers.

2 represents layers formed of mica scales 3, 8 said layers 2 being united by the substance 1 and the spaces between the scales 3 and the layers 2 being filled in with said substance.

4 represents the flexible composition cover f or coating of the insulated sheet.

5, Fig. 4:, represents sheets of tissue-paper or other flexible porous material saturated with an insulating compound and forming part of the sheet and interposed between the outer layer and the coating or cover-4'.

6 represents a bod y-plate of a table 7, which plate may be heated or cooled by means of a pipe 8 passing under said plate.

9 is a light roller to be used in pressing down the dilferent layers of the sheet during the process of manufacture and for expelling gas from the same.

The method I prefer to use in the manufacture of my improved insulating material r Fahrenheit.

is as follows: A layer of insulating material in a fluid or semifiuid state is first applied to a base-plate 6, said plate having previously been coated with soapstone or some similar material, so that after said layer has become harden ed,or partly so,it may be readily scaled from the plate. The material which I prefer to use is an oxidized oil, and preferably oxidized linseed-oil, as such oxidized oil forms in itself a very good insulator and is quite pliable when oxidized or dried. produce the best results, I take linseed-oil which has first been oxidized and then dissolve it with benzin or some similar solvent. Then I prefer to add to this dissolved oxidized oil a very small proportion of some gum, as copal-gum. This gives the oil a little more of an adhesive quality and a little more body. After'the liquid above described is applied in a layer 1 to the base-plate 6, as above stated, a layer 2 of mica scales 3 is laid on the layer 1 of said liquid, preferably overlapping each other, thenanother layer 1 of the liquid is applied over the layer of mica scales, and this process is continued until the sheet is of the desired thickness, said sheet'being made of alternate layers 1 of the insulating liquid or semiliquid and of mica scales 3. When the sheet is of the desired thickness, the plate 6 is then heated preferably, by steam from a pipe 8. The highly-volatile quality of the benzin or othersolvcnt will have caused it to evaporate to some extent evenbefore the plate is heated, thus turning the oil or other liquid into a gum, uniting the different mica scales and layers of the same. The heat from the plate wilLcause still more eva poration of the solvent and tend todry the oxidized oil. During said evaporation and drying, while the sheet is still upon the plate, a light pressure is applied to the sheet by means of a roller 9 or other device, such pressure being sufficient to smooth and level the layers of oxidized oil and mica scales and to expel the gas from the sheet; but such pressure must not be sufficient to squeeze out the oil or other binding compound, as such oil, which is now transformed into a gum, is to constitute the main portion 1 of the insulating-sheet. The sheet is then put in an oven fora short time and dried. It is then taken out of the oven and coated by dipping or otherwise in the dissolved oxidized oil or other liquid, thus fortninga coating or cover 4 to the sheet, and then hung up in the oven-say with a temperature of about 100 Fahrenheit-for about two hours, with a heat gradually increasing to about 400 The temperature of the oven is then gradually reduced for about two hours to about the degree of heat that the plate first became subjected to, which might be in the neighborhood of 100 Fahrenheit. The oxidized sheet (see Fig. 1) is now complete, and it is of a very pliable character, with the oxidized and baked oil 1 forming the main part or body of the sheet filling in all the spaces In order tobetween the mica scales 3 and between the layers of the same and uniting said scales and layers, so that the completed sheet is formed in one solid mass.

Althoughl prefer to bake the sheet,as above stated, to procure the best results, such sheet may be dried in any appropriate manner.

The scales of mica that I prefer to use in the manufacture of my new insulating material are such elementary or primary scales as are understood in mineralogy as beingthe thinnest sheets orsingle layers of mica that can be practically obtained by the continued process of cleavage or splitting. The object of forming the insulating material of such thin elementary scales is to prevent all liability of the different pieces of mica splitting, which the scales might do if they were thicker, and thus cause a splitting or separation of different parts of the insulating material, there being no oxidized oil or other adhesi ve substance between the separated layers of a double or multiple layered scale of mica. Even a partial separation of difierent parts of an insulator would leave a space for air and moisture, and thus impair the efficiency of the insulator. By reason of the use of a pliable adhesive insulating substance the finely-divided mica scales can be united in a solid mass with said substance, so that the resultant product is a sheet or body of very flexible and pliable insulating material that can be bent, doubled up, and twisted in any manner desired to suit the various forms and conditions for which insulators are used. If the adhesive substance that binds the mica scales together were not of a flexible and pliable nature, the completed insulating product could not be bent and twisted without liability of breaking. 7

The different layers of oxidized oil or other liquid may be applied with a brush or in any other appropriate manner, and the scales of the different layers should preferably overlap those of the other layers, so that the resistance offered to an electrical current in an insulator so formed would be transverse to the surfaces of the mica scales, there being always, besides the oxidized insulating compound, a scale of mica to resist the force of the electrical current. Still better results may be attained by a second coating of the plate with the dissolved oxidized oil, and it should then preferably be hung up in the oven in a reverse position to that in which it was suspended before. When this second baking is contemplated, it will not be neces sary to keep the sheet in the oven quite aslong the first time, (or it may be otherwise dried,) as the second baking will effect the desired result of thoroughly oxidizing and hardening the oil or body of the sheet and of uniting said body with the mica scales in a solid mass.

The insulating-sheet made by my improved method has been found to be most efficient as an insulator, and it will withstand a very the said compound, and then baking in the oven, as above described. When this-form of sheet is made, very small scales of mica may be used, and it will not be necessary to use as many layers of said scales as when the tissue-paper or other fabric is omitted, as the layer or layers 50f flexible material will form a durable binder for the entire sheet. oxidized composition will thoroughly impregnate the tissue-paper or other fabric and render it virtually non-carbonizable. The efficiency of said sheet as an insulator is equal to that in which the coating of flexible fabric is omitted.

By practical experience I find that the insulators made in accordance with my invention will resist at least fifteen hundred volts to one-thousandth of an inch in thickness of said insulators.

What I claim as new, and desire to secure by Letters Patent, is i 1. The improved insulating material, consisting of layers ofa pliable,adhesive, binding substance, and layers of the thinnest or primary mica scales, the said layers united to form a solid pliable mass.

2. The improved insulating material, consisting of layers of a pliable, adhesive, insulating substance, and layers of the thinnest or primary mica scales overlapping each other, the said layers unitedto form a solid pliable mass.

3. The improved insulating material, consisting of layers of a pliable, adhesive, insulating substance, and layers of the thinnest or primary mica scales, the said layers united to form a solid pliable mass, and said mass having a coating of said substance.

4. The improvedinsulating material, consisting of layers of a pliable,'adhesive, insulating substance, and layers of the thinnest or primary mica scales overlapping each other, the said layers united to form a solid pliable mass, and said mass having a coating of said substance.

5. The improved insulating material, consisting of layers of a pliable, adhesive, insulating substance, and layers of the thinnest or primary mica scales, the said layers united to form a solid pliable mass, said mass being covered with a layer of thin, porous, flexible The dized binding substance, and layers of the thinnest or primary mica scales, the said layers united to form a solid pliable mass.

7. The improved insulating material, consisting of layers of a pliable, adhesive, oxidized insulating substance, and layers of the thinnest or primary mica scales overlapping each other, the said layers united to form a solid pliable mass.

8. The improved insulating material, consisting of layers of oxidized oil and of mica scales.

9. The improved insulating material, consisting of layers of oxidized oil and of singlelayer or primary mica scales.

l0. Theimproved insulating material, consisting of layers of oxidized oil and of singlelayer or primary mica scales, said oxidized oil forming a substantial part of the body of the insulating material and uniting said scales to form a solid mass.

11. The improved insulating material, consisting of layers of oxidized oil and of irregularly-shaped mica scales.

12. The improved insulating material, consisting of layers of oxidized oil and of overlapping mica scales.

, 13. Theimprovedinsulating material, consisting of insulating oxidized oil, and layers of mica scales, said oxidized oil forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass.

14. The improved insulating material, consisting of insulating oxidized oil,- and layers of mica scales overlapping each other, said oxidized oilforming a substantial part of the body of the'insulating material, and uniting said scales to form a solid mass.

15. The improved insulating material, consisting of oxidized linseed-oil, and layers of mica scales, said oxidized oil forming a substantial part of the bod y of the insulating material, and uniting said scales to form a solid mass with the same.

16. The improved insulating material, consisting of oxidized linseed-oil, and layers of mica scales overlapping each other, said oxidized oil forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass.

17. The improved insulating material, consisting of insulating oxidized oil, and mica scales overlapping each other, said oxidized oil forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass, and said mass having a coating of said oxidized oil.

18. The improvedinsulating material, consisting of oxidized linseed-oil, and mica scales overlapping each other, said oxidized oil forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass, and said mass having a coating of said oxidized oil.

19. The improved insulating material, con

sisting of layers of oxidized oil and of irregularly-shaped overlapping mica scales.

20. The improved insulating material, consisting of layers of oxidized oil and of irregularly-shaped single layer or primary mica scales.

. 21. The improvedinsulating material, consisting of layers of oxidized coil and of overlapping single-layer or primary mica scales.

22. The improved insulating material, consisting of layers of oxidized oil and of irregularly-shaped overlapping single-layer or primary mica scales.

23. The improved insulating material, consisting of layers of oxidized oil and of irregularly-shaped singlelayer or primary mica scales, said oxidized oil forming a substantial part of the body of the insulating material and uniting said scales to form a solid mass.

24:. The improved insulating material, consisting of layers of oxidized oil and of overlapping single-layer or primary mica scales, said oxidized oil forming a substantial part of the body of the insulating material and uniting said scales to form a solid mass.

25. Theimproved insulating material, consisting of layers of oxidized oil and of irregularly -shaped overlapping single-layer or primary mica scales, said oxidized oil forming a substantial part of the body of the insulating material and uniting said scales to form a solid mass.

26. The improved insulating material, consisting of a pliable, dissolvable and adhesive insulatingsubstance,and layers of mica scales, said substance forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass, and said mass having a coating of said substance.

27. The improved insulating material, consisting of a pliable, dissolvable and adhesive oxidized insulating substance,and mica scales overlapping each other, said substance forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass, said mass being covered with a layer of thin porous flexible material,

- and said mass andlayer having a coating of said substance.

28. The improved insulating material, consisting of a pliable, dissolvable and adhesive oxidized insulating substance,and mica scales overlapping each other, said substance forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass, said mass being covered with a layer of tissue-paper, and said mass and layer having acoating of said substance.

29. The improved insulating material, consisting of a pliable, dissolvable and adhesive oxidized insulating substance, and layers of mica scales, said substance'forming a substantial part of the body of the insulating material, and uniting said scales to form a solid mass, said mass being covered with a layer of thin porous flexible material, and said mass Y and layer having a coating of said substance.

30. The improved insulating material, consisting of a pliable, dissolvable and adhesive oxidized insulating substance, and layers of mica scales overlapping each other, said substance forming a substantial part of the body of the insulating material, and uniting said scales and layers to form a solid mass, said mass being covered with a layer of thin porous flexible material, and said mass and layer having a coating of said substance.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CHARLES W. JEFFERSON. \Vitnesses:

ALLAN H. JACKSON, HOMER STRONG.