Hitachi, Ltd.

Asao Sasamoto

Hideaki Amano

Toshio Shiono

Haruhiko Hosokawa

Akio Takatsuka

Chikayuki Sogabe

Kazuo Nakagoshi

Yoshihiro Moribe

Kazuyoshi Hanada

Toshiyuki Haruna

Munesige Maeda

Motohiro Nakai

Sigeru Okamoto

Atsuo Ishida

Hideo Amano

The invention provides an improved mechanical apparatus having a driving mechanism for moving two movably contacting members relative to each other. The driving mechanism is combined with a temperature-displacement converter which drives the two members to be displaced relative to each other in response to a variation of the environmental temperature independently of operation of the driving mechanism. The temperature-displacement converter provides a fine displacement of the movable contacts in response to a variation of the environmental temperature to prevent a possible adhesive phenomenon between the two members or a possible increase of the sliding resistance between them, thereby preventing an adhesive phenomenon between a magnetic head of the CSS type and a magnetic disk of a magnetic disk device and so forth. A more effective operation is attained by further employment of a one-way clutch which is put into a coupled condition only when the relative displacement by the temperature-displacement converting means occurs in a predetermined direction but into a non-coupled condition when the relative movement is caused by the driving mechanism.

Mechanical apparatus having a mechanism for preventing conglutination of

A head positioning system includes data head arms for supporting a data head, support head arms for supporting a support head, and a head actuator for rigidly moving the data and servo head arms as a unitary structure. When there is mounted an amplifier or the like is mounted on at least one of the head arms to change the warping amount depending upon the change in the environmental temperature, a portion of the head arm on which the amplifier is mounted is cut away therefrom but is left partly connected thereto, so that the head arms are all warped in nearly the same amount.

Head arm structure mounting a circuit element in a magnetic disc device

A favorable balance of mass and strength is provided by the truss type beam formed through the use of triangular apertures in the head arm, which further can be arranged to provide a greater leading edge beam strength than trailing edge beam strength. With increased density of data and correspondingly decreased flying height, favorable results are obtained by making the outermost yaw angle greater than the innermost yaw angle. Mass unbalance can be corrected by shifting the coil position.

Magnetic head mounting arm having asymmetrical configuration

A magnetic disc unit capable of improving the throughput by minimizing the seek time for the magnetic head. The magnetic disc unit is operative to respond to a cylinder address instructed by the host unit to move the magnetic head to the corresponding cylinder position on the magnetic disc comprises a cylinder address/position assignment selecting circuit for changing the address instructed by the host unit into a new address so as to desirably change cylinder address/position assignments. A head location controlling circuit is responsive to the new address to move the magnetic head to a cylinder position corresponding to the new address. In one mode, the cylinder address/position assignment selecting circuit performs renewal of cylinder addresses such that the magnetic head passes along the magnetic disc through all of the cylinder positions designated by cylinder addresses by making a return trip between inner and outer circumferences of the magnetic disc. In another mode, the cylinder address/position assignment selecting circuit performs renewal of cylinder addresses that when the innermost cylinder address is substituted for a cylinder address instructed by the host unit, the access time for the substitutive cylinder address is minimized.

Magnetic disc unit system

A magnetic disk storage unit is proposed for cleaning away dust particles on a disk by a magnetic head 7, which is in contact with the surface of the magnetic disk when a magnetic disk 3 is stationary or rotated at a low speed, and which is floated away from the surface of the magnetic disk, as the revolution rate of the magnetic disk increases. When the magnetic disk starts to rotate or when the disk is rotating at a low speed in a continuous rotation, the magnetic head is reciprocated in the radial direction of the magnetic disk, thereby to peel off the dust particles deposited on the surface of the magnetic disk and the head with the removed dust particles then being collected by a filter.

Magnetic disk storage unit with reciprocating magnetic head for cleaning

In a magnetic disc apparatus of contact-start-stop type, when stopping the rotation of a disc, a brake is placed into operation at the beginning of contact of a magnetic head with a disc at which the number of revolutions of the disc is decreased following turning off of a power source for motor drive. The actuation of an armature of the brake is delayed through the use of a current generated by an inertia rotation of a motor. Thus, wasteful actuation of the brake while the motor is rotating at a high speed is inhibited thereby extending the lifetime of the brake.

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Odawara, Japan

Asao Sasamoto