US1939808A - Field coil - Google Patents

Description

Dec. 19, 1933. o. F. FREELAND FIELD COIL Filed Sept. 15, 1931 INVENTOJR Orville [Heel BY g %(444 ATTORNEYS 9 Hw- M a 2 n 1 (H mm Hw\\\\\\\\\\\\\.

Patented Dec. 19, 1933 PATENT OFFICE FIELD COIL Orville F. Freeland, Muskegon, Mich., assignor to Anaconda Wire and Cable Company, New York, N. Y., a corporation of Delaware Application September 16, 1931 Serial No. 563,130

3 Claims.

This invention relates to electric coils and more particularly to field coils.

One of the objects of the present invention is to provide an improved field coil product. 6 Another object is to provide improved means for anchoring the coil leads.

Other objects and advantages will become apparent as the invention is more fully disclosed.

In accordance with the objects of this inven- 10tion I have devised a novel lead anchoring means and a novel coil assembly which is clearly set forth in the accompanying drawing, wherein Fig. 1 is a perspective view of the completed coil of the present invention;

Fig. 2 is the same with the cover partly removed illustrating the lead anchoring means of the present invention;

Fig. 3 is a side elevation sectional view of the coil illustrating the elements of the coil assembly; and

Fig. 4 is an enlarged section of upper portion of coil. g

Referring to the drawing, the usual field coil 5 comprises a number of turns of copper wire 1 usually of exceedingly small gauge and coated with dielectric insulating material; wound about a tubular core 2 and retained in position thereon by side walls 3. Heretofore it has been 3 .customary to comprise the tubular core 2 and side walls 3 of a unitary assembly commonly identified as a spool. When the desired number-of turns of wire are wound upon the spool,

the entire assembly is then wrapped or enclosed in dielectric insulating material, the two ends of the copper wire only extending therefrom. One of the difliculties heretofore experienced has been in providing means to bring out the inner end of the coil without short circuiting the same to the remaining turns. Another difficulty is to provide means to anchor the fine gauged wire of the coil ends to the lead wires so that they are not subjected to tensional stresses or strains when in service.

.45 In the present invention I have overcome these two difficulties and others bycomprising the spool of two sections, a tubular core 2 and side walls 3. Side walls 3 are comprised of two sections, an inner winding washer 4 and an outer end cap 5. The inner winding washer 4 is adapted by means of segments 6 to be frictionally attached to the end of the tubular core 2 in the manner shown. The inner end of the copper coil is brought through the spool assembly at this junction in the manner indicated in Fig. 2. When the desired number of turns have been wound on the core the two ends of the coil are anchored to lead wires '1' and 8.

In accordance with the present invention the lead wires are anchored in the following manner. A flexible piece of leatheroid 12 is wound about the outside of the coil and two copper tabs 9 and 10 are attached thereto in any convenient manner or position; such as by inserting the same through slits in the leatheroid and doubling back as illustrated in Fig. 2. The ends of the coil are attached to the under section of the tabs 9 and 10, and the ends of lead wires 7 and 8 are attached to the upper section. The under section of the tab is insulated from the coil surface in any convenient manner such as by doubling over the leatheroid as shown. Preferably the tabs 9 and 10 are positioned as indicated so that the leads may be extended from one end of the coil in relatively close relationship.

End caps 5 comprised of dielectric material adapted to retain the leatheroid in position are then placed on the coil and a suitable flexible dielectric strip 11 wound about the outside 80. thereof and cemented thereto serving thereby to retain all the elements together in their assembled position. The entire coil may then be dipped, sprayed or painted with any suitable or desired electrically insulating, water and oil proofing composition.

The particular lead anchoring means I have provided permits the application of considerable tensional stresses and strains to the lead wires without the application of any strain upon the coil ends. The particular assembly of parts permits the rapid assembly of the coil, and provides a neat and finished appearance to the coil not heretofore obtainable.

There may be many modifications and adaptations made of the present invention without departing essentially from the nature and scope thereof as may be set forth in the following claims:

What I claim is:

l. A field coil comprising a tubular core and demountable end washers united thereto, a wire coil wound about said coil, a flexible dielectric strip member having a pair of metal tabs extending therethrough, the coil ends being attached to the under portion of the tab and lead wires attached to the upper section thereof, end cap members adapted to enclose the coil ends and to extend over the flexible strip member to retain said member in position upon the outer-1. 9

periphery of the coil, and an outer flexible strip member wound about the outer. periphery of the coil and adapted to be attached to the. cap and first strip member to form a unitary structure.

member wound about the outer periphery of the I coil and adapted to be attached to the cap and first strip member to form a unitary structure and an exterior dielectric, water and oil insulating coating thereover.

Y ;3. In a field coil, a coil comprised of a plurality of turns of wire wound about a core, coil terminals and anchor means therefor, said anchor means comprising a flexible strip member comprised of dielectric insulating material, metal tab members attached to said strip member with a section thereof extending through the said strip, the coil terminals being attached to the under section of said tab, and lead wires to carry the current to said coil terminals attached to the upper section of said tab.

ORVILLE F. FREELAND.

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