US791021A - Transformer. - Google Patents

Description

PATENTED MAY 30, 1905.

C. L'E G. FORTESGUE.

v TRANSPORMER.

Win11' INVENTOR ms. afm

a; AT'TORNEY WITNESSES: v

PATENTED MAY 30, 1905.

C. LE G. FORTBSCUE.

TRANSFORMBR.

APPLICATION FILED 51:21:30. 1903.

2 SHEETS-SHEET 2.

NVENTU? ATTORNEY W/TNESSES:

UNITED STATES Patented May{30, 190 5.

PATENT OFFICE.,

TO W ESTINGHOUSE ELECTRIC PORATION OF PENNSYLVANIA.

& MANUFACTURING- COMPANY, A COR- TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 791,021, dated May 30, 1905.

Application filed September 30, 1903. Serial No. 175,223.

T0 all 7011/0721/ it 1li/(ty erf/tecra:

Be it known that l, CHARLEs LE (5r. Foe- TESCUE, a subject of the King of Great Britain, and a resident of lilkinsburg in the county of Allegheny and State of Pennsylvania, have invented a new and useful 'improvement in Transformers, of which the following is a specification.

My invention relates to transformers employed in connection with alternating-current systems of distribution; and it has for its object to provide transformer core plates or punchings of such form as to insure a maximum economy of material and such as may be easily and expeditiously assembled without danger of injury to the coil insulation.

ln the accompanying drawings, Figure 1 is a view in transverse section of a transformer constructed in accordance with my invention.

Fig. 2 is a perspective view of a transformercore, some of the plates heilig' omitted. Fig. 3 is a view of a strip or blank of sheet-iron divided in accordance with my invention.

In the manufacture of transformers it is eX- tremely desirable to provide core-plates of such form as to utilize a maximum percentage of the stoel; from which the plates are punched and also such as to provide a core havinglow reluctance to the magnetic flux. The coreplates heretofore generally used in the manufacture of transformers of the shell type possess the disadvantage of being difficult to assemble and requiring a large amount of labor in the operation; but one of the most serious objections to the use of the form of punchings most commonly employed is the cutting and tearing of the insulation d u ringthe assembling operation. These objections and others I avoid in a manner to behereinafter more fully described.

The main portion of the iron core consists of plates 1 of substantially E shape, the middle cross-bar 2 being' of substantially double the width of the end cross-bars 3 and 4; and having a stepped portion 5, due to the removal of a square portion 6, the side of the square being equal to the width of the end cross-bars. The end cross-bar 4 is shorter than the bar 3 by an amount equal to its width.

rlhe side bars T are of sullicient length to span the uninclosed sides of the openings 8 and 9 and the width of an end cross-bar. The double rectangles forming the core are completed by placing the bars T at right angles to the cross-bars, so that their inner ends lit into the stepped portions of the middle cross-bar 2 and their outer ends into the spaces between the ends of the bars 3. The corners of the rectangles may be cut away, as shown at 10, 11, 12, 13, 14, and 15, in order to decrease the weight of the core, or the plates may be left with sharp corners, if preferred.

A plurality of the E-platcs are preferably placed together to form a group in order to facilitate the assembling, and alternate groups are reversed with respect to each other, substantially as shown in Fig. Q, in order to reduce the reluctance of the core. The requisite number of the groups of E-plates to form the core are built up, and the coils 16, 17, 18, and 19 are then placed in position around the central part 2 and within the spaces 8 and 9.

Non-conducting material 2O of suitable form and dimensions is placed in the rectangles before the coils are assembled, and the projecting portions are subsequently carefully wrapped about the coils. '.l he side bars 7 are then placed in position substantially as indicated in Figs. 1 and 2. Herein lies a great advantage of my improvement over the construction commonly employed in that the major portion of the core may be assembled separately from the coils. Heretofore the coils were first assembled and then wrapped with non-conducting material and bound together by means of tape or cord, after which the entire core was built up around the coils. It is unnecessary to bind together the coils of a transformer constructed in accordance with my invention, and itis desirable not to do so, since the coils may then be more easily removed for repairs.

In Fig. 3 l have shown how the E-plates may be punched from strips of sheet metal so as to afford a maximum economy of material, the shaded portions indicating the waste material. The sheet-metal blanks 2l are Wider than the E-plates by an amount equal to the width of the end cross-bars 3 and 4. The

plates 7 may be punched from new sheetmetal'blanks with'little or no waste, or they .maybe punched from Waste material result- .former soconstructed has a..low degree oi' reluctance to the magnetic'fiux.

The .forms of Vthe several lparts and their Vrelative proportions may be somewhat varied within thescope of my invention, andI thereffore disclaim any intention to restrict the'inventicn to :any narrower-limits than may be imposed-by-fthe prior art and the demands of satisfactory service.

I- claim asmy invention- 1. A laminated transformer-core consisting of successive E-shaped elements the middle cross-bars of which have stepped .free ends land the-end cross-bars of which are of substantially one-half 'thewidthof the middle cross-bars and of unequal length, and separate plates at right angles tothe crossbars and A completing therectangular inclosures forthe Winding. v

2. Alaminated transformer-core consisting of successivelE-shaped elements, some of which are transposed with respect tothe others, the middle cross-bars of `which have-stepped free ends and the end cross-bars of which are of substantially 'one-half the width ofthe middlecross-barsand of unequallength, and separate plates .at right angles to the crossbars and completing the rectangular linclosures for the winding.

3. A laminated transformer-core consisting of successive groups of `Eshaped elements alternately transposed with respect to each other the middle cross-bars of which have stepped free ends and the end cross-bars of which are of substantially one-half the width l of the middle cross-bars and of unequal length,

and separate plates at right angles tothe crossbarsand completing the rectangular inclosures for the winding.

4. A laminated transformer-core comprising a-plurality of alternately-reversed sets of E-shaped plates the middle cross-bars of which have stepped free ends and the end crossbars of which are of substantiallyone-half the width ofthe middle bar` and independent sets of bars the ends oi which are seated in the steps in the middle bars :and in the spaces between the longer. end bars.

5. A transformercore-plate ofE shape,fthe end bars of'which are substantially one-half the width of the middle bar and of unequal length and :the -middle bar of which has a stepped free end forming two lengths .the shorter of which is adjacent to the longer end bar.

6. An.electrical-transformer comprising a plurality of grou ps ofalternately-reversed E- shaped plates having middle-bars provided with stepped free ends and end bars of substantially one-half the width' ofthe middle bars and of` unequal length, coils surrounding the middlebarsand groups of straightbarsthe endsfof which lit into the stepsin the ends of the middle bars and :between thev ends of the longe-r end bars.

.7. An electrical transformer comprising coils anda core surrounding'the same, said core comprisinga set of supe1posed,fE-shaped plates and `two sets of :removableplates for closingthe spaces between the end` and 'middie bars of the E-s'haped structure.

- Intestimony `whereofl have hereunto subscribed my namethis 28th day of September, 1903.

-CHARLES LE -G. FORTESOUE. 'VVitnessess I. L. GRIFFITH, :BIRNEY HINEs

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