Abstract: A parallel mechanism has a plurality of arms. Each of the arms has a ball joint. The ball joint includes a ball stud with a shaft portion and ball-shaped head, and a socket swingably and pivotally movably holding the ball-shaped head of the ball stud. The socket includes a semispherical recess portion holding the ball-shaped head from a top portion to an equator thereof, and an extending portion which is smoothly continuous with the semispherical recess portion and which extends from the equator of the ball-shaped head to the shaft portion side. The inner diameter of an opening in the extending portion is equal to or larger than the diameter of the ball-shaped head.

Abstract: A parallel mechanism includes a base, actuators attached to the base, a plurality of arms coupled together in parallel, and a sensing device. Each of the arms has a first link, one end of which is coupled to the actuator, a second link through which the other end of the first link and a bracket are coupled together, a ball joint through which one end of the second link and the other end of the first link are swingably coupled together, and a ball joint through which the other end of the second link and the bracket are swingably coupled together. Each of the ball joints includes a ball stud including a ball-shaped head, a socket swingably holding the ball-shaped head of the ball stud, and a conductive member interposed between the ball-shaped head and the socket. The sensing device senses when at least one of the plurality of ball joints is loose, based on whether or not the ball stud and the socket are electrically continuous with one another.

Abstract: An apparatus surely measures the vibration characteristic of a head gimbal assembly and has a wide range of resonance frequencies to be set, the apparatus has a first laser Doppler vibrometer to detect a vibration velocity of a shaker, a second laser Doppler vibrometer to detect a vibration velocity of a head of the head gimbal assembly fixed to a fixture, and a reflection mirror to orthogonally reflect a laser beam emitted from the first laser Doppler vibrometer toward the fixture fixed to the shaker, and the apparatus finds the vibration characteristic of the head gimbal assembly according to the detected vibration velocities.

Abstract: A disc drive apparatus has a base, a disc, and a carriage. The base has a first vibration mode and a second vibration mode as reference vibration modes with respect to frequency response characteristics observed when the disc drive apparatus is shaken. The second vibration mode has a low-frequency second vibration mode (Base 2nd-1), in which a waveform peak is created on the low-frequency side, and a high-frequency second vibration mode (Base 2nd-2), in which a waveform peak is created on the high-frequency side. The two second vibration modes (Base 2nd-1 and Base 2nd-2) have a relationship such that the phase of a pivot position is inverted between them. A frequency of a first bending mode of an arm of the carriage is set in a frequency domain in a trough between the two second vibration modes.

Abstract: A carriage for a disc device, which has a top arm, bottom arm, and mid arm, has a main mode, end arm mode, and mid arm mode as a frequency response obtained when subjected to a vertical shake. In the main mode, all of the top, bottom, and mid arms swing at a first frequency within the same phase in a primary bending mode. In an end arm mode, the top and bottom arms swing at a second frequency higher than the first frequency within opposite phases and with an amplitude larger than that of the mid arm. In the mid arm mode, the mid arm swings at a third frequency having a difference of 50 Hz or less from the second frequency within the same phase as in the main mode, and the top and bottom arms swing within the phase opposite from that in the main mode.

Abstract: An apparatus surely measures the vibration characteristic of a head gimbal assembly and has a wide range of resonance frequencies to be set, the apparatus has a first laser Doppler vibrometer to detect a vibration velocity of a shaker, a second laser Doppler vibrometer to detect a vibration velocity of a head of the head gimbal assembly fixed to a fixture, and a reflection mirror to orthogonally reflect a laser beam emitted from the first laser Doppler vibrometer toward the fixture fixed to the shaker, and the apparatus finds the vibration characteristic of the head gimbal assembly according to the detected vibration velocities.

Abstract: A head suspension restricts deformation of a flexure caused by frictional force produced between a hard disk and a slider when the hard disk turns in a reverse direction. The head suspension has a load beam resiliently supported with a base. The base is supported with an arm that is turned around an axis. The load beam applies load onto a head having a slider to write and read data to and from the hard disk. The flexure is attached to the load beam and has a tongue that supports the slider. The flexure is provided with a limiter that limits displacement of the tongue due to frictional force produced between the hard disk and the slider when the hard disk is reversely turned. The limiter is on the base side and faces a free end of the tongue. The limiter is integrally formed from a part of the flexure, to face the free end of the tongue.

Abstract: A suspension comprises a baseplate having a boss portion, a beam portion with a flexure, and a hinge member. The hinge member includes a connecting portion that can bend in the thickness direction thereof between the baseplate and the beam portion. If the length of the suspension from a pivot portion on the distal end portion of the beam portion to the center of the boss portion is 14.5 mm, the thickness of the baseplate is 0.175 mm or greater, the width of the baseplate is 4.5 mm or greater, the length of the connecting portion of the hinge member is 0.7 mm or shorter, and the length of the baseplate is 5.04 mm or shorter.

Abstract: A suspension for disc drive comprises a load beam fitted with a flexure, an actuator base including a base plate, a hinge member thinner than the base plate, and a pair of piezoelectric ceramic elements. The piezoelectric ceramic elements displace the distal end portion of the load beam in a sway direction when supplied with voltage. Each piezoelectric ceramic element is stored in an opening portion in the actuator base. A covering material such as an adhesive agent that fills the space between the peripheral edge portion of the piezoelectric ceramic element and the actuator base forms a cover portion that covers the opposite end faces and the opposite side faces of the ceramic element.

Abstract: A suspension for disc drive comprises a load beam fitted with a flexure, an actuator base including a base plate, a hinge member thinner than the base plate, and a pair of piezoelectric ceramic elements. Each piezoelectric ceramic element is stored in an opening portion in the actuator base and fixed to the actuator base by an adhesive layer. The adhesive layer includes an electrical insulating adhesive agent and a large number of fillers of an insulating material mixed in the adhesive agent. The fillers are interposed between each piezoelectric ceramic element and the actuator base to secure a clearance for electrical insulation between the two.

Abstract: A suspension comprises a baseplate having a boss portion, a beam portion with a flexure, and a hinge member. The hinge member includes a connecting portion that can bend in the thickness direction thereof between the baseplate and the beam portion. If the length of the suspension from a pivot portion on the distal end portion of the beam portion to the center of the boss portion is 14.5 mm, the thickness of the baseplate is 0.175 mm or greater, the width of the baseplate is 4.5 mm or greater, the length of the connecting portion of the hinge member is 0.7 mm or shorter, and the length of the baseplate is 5.04 mm or shorter.

Abstract: A suspension for disc drive comprises a load beam fitted with a flexure, an actuator base including a base plate, a hinge member thinner than the base plate, and a pair of piezoelectric ceramic elements. Each piezoelectric ceramic element is stored in an opening portion in the actuator base and fixed to the actuator base by means of an adhesive layer. The adhesive layer includes an electrical insulating adhesive agent and a large number of fillers of an insulating material mixed in the adhesive agent. The fillers are interposed between each piezoelectric ceramic element and the actuator base to secure a clearance for electrical insulation between the two.

Abstract: A suspension for disc drive comprises a load beam fitted with a flexure, an actuator base including a base plate, a hinge member thinner than the base plate, and a pair of piezoelectric ceramic elements. The piezoelectric ceramic elements displace the distal end portion of the load beam in a sway direction when supplied with voltage. Each piezoelectric ceramic element is stored in an opening portion in the actuator base. A covering material such as an adhesive agent that fills the space between the peripheral edge portion of the piezoelectric ceramic element and the actuator base forms a cover portion that covers the opposite end faces and the opposite side faces of the ceramic element.