(No Model.) 2 Sheets-Sheet 1.

A. L. BIKER. MAGNETIC FRAME FOR FIELD MAGNETS.

No. 507,689. Patented Oct. 31,1893.

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(No Model.) 2 Sheets-Sheet 2.

A. BIKER MAGNETIC-FRAME F03 FIELD MAGNETS. No. 507,689. Patented 001;. 31, 1893.

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UNITED STATES PATENT OFFICE.

ANDREW L. RIKER, OF NEWV YORK, N. Y.

MAGNETIC FRAME FOR FIELD-MAGNETS.

SPECIFICATION forming part of Letters Patent No. 507,689, dated October 31, 1893.

Application filed July 27, 1893. Serial No. 481,603. (No model.)

To all whom, it may concern.-

Be it known that I, ANDREW L. RIKER, of New York city, New York, have invented a new and useful Improvement in Magnetic Frames for Field-Magnets, which is fully set forth in the following specification.

The presentinvention'has reference to the construction of magnetic frames for the fieldmagnets of multipolar dynamos or motors and more especially to the construction of laminated frames, built up into a solid structure from blanks orstampings of softwrought iron. Structures of this general character are described in Letters-Patent granted to me November 20, 1888, No. 393,266, and May 19, 1891, No. 452,717. In both of these structures the continuous frame was built up of elements of the same pattern,-.and so put together that it could be separated into two like parts. In the later patent the frame was of the ironclad type having inwardly projecting cores upon which the spools of wire could be readily placed. In the former patent the construction was such that the wires had to be wound directly upon the cores. Both structures required the use of blanks of large dimensions.

The general plan or principle of construction here referred to is found to be practical both mechanically and electrically, and to result in highly eflicient machines, and the object of the present invention is to improve upon the modes of construction pointed out in the aforesaid patents, particularly for machines of large size, to facilitate and cheapen the construction of such machines, and to realize other advantages as will be apparent from the detaileddescription contained herein.

The construction hereinafter described and claimed has been found in practice to be very advantageous for the purpose specified, and applicable tomachines varying from machines of medium size to those of the largest capacity.

The main feature of the present invention consists in the employment of two blanks, which may be distinguished as the core-blank and pole blank, respectively, and in the shape of these blanks, which gives them reversibility and permits the core sections and pole sec tions to be built up and bolted together, half of the entire number of blanks in each being turned in one direction and half in the other.

The invention permits each section to be fitted solidly into the adjacent sections by tongue and groove joints makinga structure of great strength, yet from which each section can be taken out separately without disturbing other parts of the frame. Furthermore these results are attained without anysuperfluous metal in the frame, and with a minimum of wastage in cutting the sheets from which the blanks are stamped.

The invention, and its advantages, will be better understood by reference to the accompanying drawings,in which- Figure I represents the shape of a pole blank, and Fig. II the shape of a core blank. Fig. III represents in elevation the outline of a six-pole dynamo or motor. Figs. IV and V are details illustrating how the pole-sections and core sections are built up. Fig. VI a perspective view of a finished pole-section.

The shape of the blanks 1, 2 and the manner in which they are laid together to form a solid continuous ring (without over-lapping parts) will be understood from the drawings. It will also be observed from Fig. III that each blank can be turned in the opposite direction from that which it occupies in that figure, and that the resulting ring will fit exactly upon that shown in the figure with perfect coincidence of all the bolt holes. The blank 1 has an inwardly projecting polar extension 3 in which are two small rivet holes 4. It also has a large central bolt hole 5 through which pass the large bolts 6 (Fig. III) which clamp the magnet frame between the iron rings usually placed at the sides of the machines of this type. In building up the blanks 1 to form a pole-section I usually take a group of four or five blanks togetherin the same position; and then a group of equal number in the reverse position, as shown in Fig. V. When so arranged each blank has a portion 7 projecting at one side beyond the edge of the oppositely turned blanks, forming recesses or spaces in the otherwise solid figure. These recesses or spaces are exactly filled by the curved ends of the core-sections, making the frame solid throughout. In the proj ecting part? of the core sections are boltholes 9, and in the corresponding parts of the core blanks 2 are similar holes 10. A single bolt passing through these overlapping parts fastens adjacent sections together in such manher that any section can be removed independently of the others. The shape of the blanks and the manner of assembling them result in depressions 12 in the frame opposite the middle of each pole-piece, at which points it is desirable to diminish the thickness and magnetic-capacity of the ring.

The method of building up large solid frames from blanks of small size, and in separate detachable sections I believe to be entirely new. Obviously it may, with slight modification, be applied to machines having eight or more poles.

Having thus described my invention, what- Iclaim as new, and desire to secure by Letters Patent, is

A laminated field-magnet frame for multi- ANDREXV L. BIKER.

Witnesses:

CORNELIUS J. JORDAN, WM. W. RICHARD.