US1984911A - Mica insulator - Google Patents
Mica insulator Download PDFInfo
- Publication number
- US1984911A US1984911A US55803131A US1984911A US 1984911 A US1984911 A US 1984911A US 55803131 A US55803131 A US 55803131A US 1984911 A US1984911 A US 1984911A
- Authority
- US
- United States
- Prior art keywords
- mica
- cellulose
- cellulose acetate
- coating
- segments
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B19/00—Layered products comprising a layer of natural mineral fibres or particles, e.g. asbestos, mica
- B32B19/02—Layered products comprising a layer of natural mineral fibres or particles, e.g. asbestos, mica the layer of fibres or particles being impregnated or embedded in a plastic substance
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/02—Macromolecular compounds
- C04B26/22—Natural resins, e.g. rosin
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/25—Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
- Y10T428/251—Mica
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31844—Of natural gum, rosin, natural oil or lac
- Y10T428/31848—Next to cellulosic
Definitions
- This invention relates to articles made of mica,
- mica' is in wide use for making parts of electrical equipment which must be non-conductors of electricity, such as commutator rings and segments, tape for armature windings, and insulation tubes.
- a binder from which the desired parts can be made. This *iS usually done, either manually or by machine, by showering mica in small flakes upon a table or other suitable surface, cementing together the particles by adding a binder in liquid form, such as shellac, copal or glyptol, rolling the mixture, and repeating the operation until a composite sheet of the. desired thickness is built up.
- the insulating parts are then cut out, die shaped, or otherwise worked into the desired articles from the composite sheets of mica.
- the articles thus prepared make suitable in? sulating pieces for use in electrical equipment, so far as their insulating qualities are concerned, but they are not entirely satisfactory as they are subject to defects inherent in their nature, such as the flaking off or feathering of the mica, and sticking of the pieces in assembling machines.
- the tendency of the mica to flake of! greatly shortens the life of the insulating pieces, as excessive handling causes them to'disintegrate.
- the mica tape for winding armatures likewise is defective because as the mica particles are small and do 'not overlap to any great extent, thetape will easily break or tear.
- the object of our invention is to eliminate and overcome these defects, and this has been achieved by applying -a*-'coating of cellulose acetate, viscose, or the like to the mica com msition, which adheres to the binder in the composition.
- Fig. 1 is across sectional view of a commutator ringcoated on-its top side with the covering film.
- Fig. 2 is a perspective iew of a strip of mica tape coated on both sides.
- Fig. 3 is a lateral cross section thereof.
- 10 represents the composite mixture of mica andshellac and 11 the protective coveringor film of cellulose acetate, viscose or the like, commonly known as Cellophane, and which materials are obtained by chemically treating cellulose.
- the coating of cellulose acetate or regenerated cellulose is preferably applied to the top side of the composite sheet of mica before the pieces are cut or stamped out therefrom, but it may be applied to both sides and to the piece after it has been stamped out, if desired.
- the protective coating of cellulose acetate or regenerated cellulose easily adheres to the mica because of the adhesive binder in the mica sheet, but an extra coating of the binder is usually used to make the covering adhere better to the mica sheet.
- the protective coating of cellulose acetate on the composite sheet, and on the-commutator rings and segments, and other insulating pieces stamped therefrom the efiective life of the pieces is greatly lengthened, as the coating protects them from flaking oif from handling.
- the protective covering is ordinarily transparent, which is an advantage in itself.
- Figs. 2 and 3 are shown a perspective an cross sectional view of a strip of mica tape similarly coated.
- the mica tape is made much thinner than the usual composite sheet and the addition of the protective coating on both sides greatly increases the strength of the tape.
- mica commutator segments are given the protective covering of cellulose acetate, the segments are particularly adapted for use in commutator assembling machines which assemble one segment of mica and one of copper alternately.
- the protective covering gives the surface of the mica segment a very smooth finish" so that individual mica segments do not stick together and impair the operation of the machine. It is very important in an assembling machine that the mica segments do not stick together, as the segments must be assembled in alternate relation of mica and copper.
- the addition of the protective coating to the composite sheet likewise greatly facilitates the making of the commutator segments, as it has hitherto been found impractical to feed them automatically to a press because of the tendency of the sheets to interlock.
- cellulose acetate or the like As the protective coating of cellulose acetate or the like is non-conductive of electricity, the insulating properties of the mica piece are not affected by the coating. Of the many substances tried, we have found cellulose acetate and regenerated cellulose most satisfactory for achieving all the desired results. Where chemically treated cellulose is mentioned in the claims, it is understood to include cellulose acetate, regenerated cellulose made from viscose and other cellulosic compounds or esters, as well as other cellulosic materials having equivalent characteristics.
- a composite sheet of mica and a binder, and a supporting and covering film therefor comprising a preformed, substantially continuous sheet of chemically treated, substantially transparent cellulose having substantially the characteristics of cellulose acetate and/or regenerated cellulose.
- each of said films comprising a preformed, substantially continuous sheet of chemically treated, substantially transparent cellulose having substantially the characteristics of cellulose acetate and/or regenerated cellulose.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacture Of Motors, Generators (AREA)
- Insulating Bodies (AREA)
- Motor Or Generator Current Collectors (AREA)
Description
Dec. 18, 1934. w H. BANKS, JR.. ET AL 1,934,911
' MICA INSULATOR Filed Aug. 19, 1931 IN'v N+URSZ macaw Patented Dec. 18, 1934 UNITED STATES PATENT OFFICE Graham, Saugus, Mass.,
assignors to The Macallen Company, Boston, Mass., a corporation of Massachusetts Application August 19,
1931, Serial No. 558,031
This invention relates to articles made of mica,
and particularly to treating such articles by coating them with a thin covering of chemically treated cellulose, such as cellulose acetate, viscose'or regenerated cellulose.
As is well known, mica'is in wide use for making parts of electrical equipment which must be non-conductors of electricity, such as commutator rings and segments, tape for armature windings, and insulation tubes. As the natural mica does not possess the necessary area, thickness, cohesion and pliability for making such' insulating parts, it is customary to prepare composite sheets of mica cemented together with a binder from which the desired parts can be made. This *iS usually done, either manually or by machine, by showering mica in small flakes upon a table or other suitable surface, cementing together the particles by adding a binder in liquid form, such as shellac, copal or glyptol, rolling the mixture, and repeating the operation until a composite sheet of the. desired thickness is built up. The insulating parts are then cut out, die shaped, or otherwise worked into the desired articles from the composite sheets of mica.
The articles thus prepared make suitable in? sulating pieces for use in electrical equipment, so far as their insulating qualities are concerned, but they are not entirely satisfactory as they are subject to defects inherent in their nature, such as the flaking off or feathering of the mica, and sticking of the pieces in assembling machines. The tendency of the mica to flake of! greatly shortens the life of the insulating pieces, as excessive handling causes them to'disintegrate. The mica tape for winding armatures likewise is defective because as the mica particles are small and do 'not overlap to any great extent, thetape will easily break or tear.
The object of our invention is to eliminate and overcome these defects, and this has been achieved by applying -a*-'coating of cellulose acetate, viscose, or the like to the mica com msition, which adheres to the binder in the composition.
Other objects of this invention will appear in the following description andappended claims,
, reference being had to theaccompanying drawing forming )a part of this specification.
Fig. 1 is across sectional view of a commutator ringcoated on-its top side with the covering film.
, Fig. 2 is a perspective iew of a strip of mica tape coated on both sides.
Fig. 3 is a lateral cross section thereof.
. Before explaining in detail the present invention, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the invention is capable of other embodiments and of being practised or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. and it is not intended to limit the invention beyond the terms of the several claims hereto appended as considered in view of the prior art and the requirements thereof.
. Referring to Fig. 1, 10 represents the composite mixture of mica andshellac and 11 the protective coveringor film of cellulose acetate, viscose or the like, commonly known as Cellophane, and which materials are obtained by chemically treating cellulose. The coating of cellulose acetate or regenerated cellulose is preferably applied to the top side of the composite sheet of mica before the pieces are cut or stamped out therefrom, but it may be applied to both sides and to the piece after it has been stamped out, if desired. The protective coating of cellulose acetate or regenerated cellulose easily adheres to the mica because of the adhesive binder in the mica sheet, but an extra coating of the binder is usually used to make the covering adhere better to the mica sheet. With the protective coating of cellulose acetate on the composite sheet, and on the-commutator rings and segments, and other insulating pieces stamped therefrom, the efiective life of the pieces is greatly lengthened, as the coating protects them from flaking oif from handling. The protective covering is ordinarily transparent, which is an advantage in itself.
In Figs. 2 and 3 are shown a perspective an cross sectional view of a strip of mica tape similarly coated. The mica tape is made much thinner than the usual composite sheet and the addition of the protective coating on both sides greatly increases the strength of the tape.
Numerous other insulating parts may be made, the pieces shown in the drawing being used for purposes of illustration only. When mica commutator segments are given the protective covering of cellulose acetate, the segments are particularly adapted for use in commutator assembling machines which assemble one segment of mica and one of copper alternately. The protective covering gives the surface of the mica segment a very smooth finish" so that individual mica segments do not stick together and impair the operation of the machine. It is very important in an assembling machine that the mica segments do not stick together, as the segments must be assembled in alternate relation of mica and copper.
The addition of the protective coating to the composite sheet likewise greatly facilitates the making of the commutator segments, as it has hitherto been found impractical to feed them automatically to a press because of the tendency of the sheets to interlock.
As the protective coating of cellulose acetate or the like is non-conductive of electricity, the insulating properties of the mica piece are not affected by the coating. Of the many substances tried, we have found cellulose acetate and regenerated cellulose most satisfactory for achieving all the desired results. Where chemically treated cellulose is mentioned in the claims, it is understood to include cellulose acetate, regenerated cellulose made from viscose and other cellulosic compounds or esters, as well as other cellulosic materials having equivalent characteristics.
We claim:
1. As an article of manufacture, a composite sheet of mica and a binder, and a supporting and covering film therefor, said film comprising a preformed, substantially continuous sheet of chemically treated, substantially transparent cellulose having substantially the characteristics of cellulose acetate and/or regenerated cellulose.
2. As an article of manufacture, a composite sheet of mica and a binder and a supporting and covering film on both faces thereof, each of said films comprising a preformed, substantially continuous sheet of chemically treated, substantially transparent cellulose having substantially the characteristics of cellulose acetate and/or regenerated cellulose. I
WILLIAM H. BANKS, JR. WALTER A. GRAHAM.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US55803131 US1984911A (en) | 1931-08-19 | 1931-08-19 | Mica insulator |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US55803131 US1984911A (en) | 1931-08-19 | 1931-08-19 | Mica insulator |
Publications (1)
Publication Number | Publication Date |
---|---|
US1984911A true US1984911A (en) | 1934-12-18 |
Family
ID=24227888
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US55803131 Expired - Lifetime US1984911A (en) | 1931-08-19 | 1931-08-19 | Mica insulator |
Country Status (1)
Country | Link |
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US (1) | US1984911A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2475877A (en) * | 1942-10-09 | 1949-07-12 | Western Electric Co | Method of treating material in laminar form |
US2477791A (en) * | 1943-04-17 | 1949-08-02 | Westinghouse Electric Corp | Insulation for electrical apparatus |
-
1931
- 1931-08-19 US US55803131 patent/US1984911A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2475877A (en) * | 1942-10-09 | 1949-07-12 | Western Electric Co | Method of treating material in laminar form |
US2477791A (en) * | 1943-04-17 | 1949-08-02 | Westinghouse Electric Corp | Insulation for electrical apparatus |
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