Method of manufactuirng a magnetic head having a glass spacer

Claim 1

A METHNOD OF MANUFACTURING MAGNETIC HEADS CONSISTING OF AT LEAST TWO CIRCUIT PARTS OF SINTERED OXIDIC FERROMAGNETIC MATERIAL WITH A GAP THEREBETWEEN FILLED WITH GLASS SERVING AS A PROTECTION AND A MECHANICAL CONNECTION MEANS, COMPRISING: ACCURATELY MACHINING AT LEAST ONE SURFACE OF EACH OF SAID TWO CIRCUIT PARTS, ARRANGING SAID PARTS ONE UPON THE OTHER WITH THE MACHINED SURFACES FACING EACH OTHER, PLACING A GLASS SHEET HAVING SIDE PORTIONS AND TOP AND BOTTOM PORTIONS BETWEEN THE PARTS WITH THE TOP AND BOTTOM PORTIONS CONTACTING SAID SURFACES, THE THICKNESS OF THE GLASS SHEET BEING GREATER THAN THE FINALLY DESIRED GAP LENGTH, PLACING MICA SPACERS BETWEEN SAID SURFACES ADJACENT TO AND ABUTTING ONLY THE SIDE PORTIONS OF SAID GLASS SHEET, SAID MICA HAVING A HIGHER MELTING TEMPERTURE THAN SAID GLASS, SAID MICA SPACERS HAVING A THICNKESS SUBSTANTIALLY EQUAL TO THE FINALLY DESIRED GAP LENGTH, HEATING THE ASSEMBLY THUS OBTAINED TO A TEMPERATURE IN THE MELTING RANGE OF THE GLASS, PRESSING THE PARTS AGAINST EACH OTHER AT SAID TEMPERATURE, COOLING THE ASSEMBLY, AND GRINDING AWAY THE PORTIONS OF THE CIRCUIT PARTS INCLUDING THE MICA WHEN THE ASSEMBLY HAS BEEN COOLED.