Abstract: In a magnetic recording medium having a ferromagnetic metallic thin film formed on a substrate as a recording film, the recording film is formed from low density crystalline particles and impregnated with lubricant among the crystalline particles to improve the corrosion-resistivity and the slide-resistivity for a magnetic head.

Abstract: A stepless speed change traction gear includes a plurality of conical rollers, each having a conical surface frictionally engaging with an internal surface of a speed changing ring, a flat surface perpendicular to the axis of the conical surface frictionally engaging a non-rotating track ring, and an annular concave surface coaxial with the conical surface and frictionally engaging a bearing ring. The speed changing ring is longitudinally adjustable between limits so that a speed ratio range from 0 to nearly 1.0 is developed. This traction gear is not provided any additional gearing or speed increasing device to widen the speed range. A clutch, brake, and operator can permit a direct drive condition between the input and output shafts.

Abstract: Disclosed are a magnetic recording medium having a magnetic recording layer formed of a magnetic thin film in which rotational hysteresis integral R.sub.H is within a range of from 0.4 to 1.3 in the measurement by a torque magnetometer, and a continuous magnetic recording medium in which crystal grains are substantially randomly arranged on the upper surface of a magnetic recording layer or on the surface of a non-magnetic subbing layer, and in which each of the crystal grains is made to be in the form of an ellipsoid or needle and to have a length-ways axial ratio of a major axis to a minor axis not smaller than 2, more preferably, not smaller than 4.

Abstract: A magnetic recording medium in which a non-magnetic intermediate layer made of an alloy substantially composed of at least one element selected from the group consisting of Zr, Hf, Ta, Ti and Nb is disposed between a magnetic layer formed on a substrate and a non-magnetic overcoat layer formed on the magnetic layer. Since the impact shock resistance and the vibration resistance of the magnetic recording medium can be improved and the head-medium spacing of the magnetic disc apparatus can be decreased extremely by disposing the non-magnetic intermediate layer, it can provide a increase in the recording density, particularly, in a thin film type magnetic recording medium using a metallic magnetic thin film or metal oxide thin film as the magnetic layer. It can also improve the corrosion resistance in the case of a metallic magnetic thin film type medium.

Abstract: Disclosed is a magnetic recording medium of the magnetic metal thin-film type for longitudinal recording, in which the noise is reduced by selecting the value of maximum torque L (the product of magnetic anisotropy energy Ku and magnetic layer volume v; as measured by setting the axis of rotation in plane of the medium) and the value of magnetic flux .phi. (the product of saturation magnetization Ms and magnetic layer volume v) from a range defined by 0<L/(2.pi..multidot..phi..sup.2)<4.times.10.sup.5 (erg/emu.sup.2).