Filament wound pressure rings for small power transformers

Epoxy-glass pressure rings which can be used to clamp and hold the coils of core-form transformers aaginst axial magnetic thrust have been developed. Manufacturing of the parts is accomplished by random continuous wet winding of multiple strands of glass filaments in a mold to a radial build of two to eight inches. Subsequent thermal processing provides mechanical and insulating strength and stability in the pieces such that these may be considered replacements for the steel parts presently used in oil- and Inerteen^®-filled apparatus.