| 摘要 |
796,306. Magnetic recording heads. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Oct. 1, 1956 [Oct. 4, 1955], No. 29850/56. Class 40 (2). An annular magnetic recorder/reproducer head comprises at least two circuit parts of sintered ferromagnetic oxide 1 and 2 and one airgap 4 which is filled with a glass 6 having a coefficient of expansion within 5 per cent of that of the ferromagnetic material at its normal operating temperature (ambient) and preferably not differing by more than 10 per cent up to the softening temperature of the glass. Examples are given of suitable compositions of ferromagnetic oxide and glass which may be used together. An additional quantity of glass (shown shaded under the air gap) improves the mechanical strength of the structure. The glass is introduced into the air-gap as a foil, the assembly is heated to the softening temperature of the glass and then allowed to cool under a pressure sufficient to achieve the required gap width. |
