Abstract: There is disclosed a magnetic head assembly for use in a disk drive that can store and retrieve data from a magnetic disk. The assembly has a carriage and an arm on which a lower magnetic head and an upper magnetic head are carried, respectively. A hinged leaf spring is located on the carriage remotely from the heads. The arm can swing about the spring which is welded to the spring mount portion of the carriage.

Abstract: A bearing device for rotatably supporting the end of a rotational shaft through a slide bearing to a base comprising a through opening perforated at a part of the base for press-fitting the slide bearing, and a retainer containing opening formed at the base to substantially perpendicularly cross the through opening, and a retainer disposed in the retainer containing opening of the base for bearing the axial force of the rotational shaft, thereby reducing the manufacturing cost and improving its accuracy.

Abstract: A disk recording-reproducing device having a carriage with a read/write head, a screw shaft to shift the carriage with an engaging element through coupling between a spiral groove of the screw shaft and the engaging element, and a stepping motor to rotate the screw shaft. The spiral groove is composed of a number of groove portions each with a straight bottom whose angle of lead is substantially zero degree that are displaced successively, circumferentially and axially. Preferably, the screw shaft has plane portions for its positioning, and a rotor of the stepping motor has magnetization points being set correspondingly to the lines of the groove portions.

Abstract: A device for shifting a carriage on which the magnetic head of a disk drive is carried, the disk drive being used with magnetic disks. A mating element mounted to the carriage is in resilient contact with a helical groove formed on a threaded shaft. A retaining member having a retaining portion is mounted on the carriage. The retaining portion is usually not in contact with the wall defining the helical groove, but bears against the wall when the shaft stops abruptly or a strong external force is applied, for example. Thus, the mating element is prevented from disengaging from the groove.

Abstract: Herein disclosed is a carriage driving mechanism for use with a floppy disc drive or the like to drive a carriage carrying a magnetic head so that the magnetic head may be driven to a desired track on the floppy disc to record or read out data in or from a floppy disc. The carriage driving mechanism comprises: a drive shaft having a helical guide groove in its outer circumference; a prime mover for turning the drive shaft; a guide shaft extending in parallel with the drive shaft; a carriage mounted slidably on the guide shaft; and a follower carried on the carriage and engaging with the guide groove of the drive shaft. A spring member is carried on the carriage to mount the follower thereon so that the follower may have its tip guided elastically by the guide groove of the drive shaft.

Abstract: In a stepping motor comprising a stator including a plurality of stator plates, and a rotor made of a permanent magnet, a coating layer made of a nonmagnetic material is applied to the stator plates, and the rotor is rotated within the stator plates while the rotor is maintained in a closely adjacent relation contactable with the coating layer of the stator plates.

Abstract: In a recording and reproducing device for a magnetic disc, including a carriage supporting a magnetic head, an engaging piece secured to the carriage, and a screw threaded shaft engaging with the engaging piece for causing a linear shift of the carriage, the screw threaded shaft is formed with a plurality of groove portions. Each of the groove portions has a substantially linear groove bottom of a leading angle substantially equal to 0.degree.. The groove portions are arranged in an equally spaced apart relation around the surface of the shaft so that the portions are mutually displaced in the axial direction of the shaft by a predetermined distance, and that when these are connected together, a kind of helical groove is formed around the surface of the shaft. To be cooperative with the helical groove, the engaging piece is provided with a linear projecting end portion engageable with each of the groove portions.

Abstract: An intermittent drive member comprises a shaft with a spiral groove formed in the outer periphery of the shaft. The spiral groove includes a plurality of groove portions each having a linear bottom portion with a lead angle of zero degrees and a plurality of chamfered portions. The groove portions are successively formed by being axially shifted one after one along the shaft, and each of the chamfered portions forms the connection between adjacent groove portions.The intermittent drive member is employed in a mechanism which includes an electric motor for driving the shaft and a movable member having a tip end portion slidably fitted in the spiral groove so that the movable member is displaced when the shaft is rotated. The shaft is rotated to move the movable member in a predetermined direction when the tip end portion is in each of the chamfered portions, while the motor is deenergized to stop the movement of the shaft when the tip end portion is in each of the groove portions.