Dynamic magnetic information storage or retrieval – Record transport with head stationary during transducing – Drum record
Patent
1997-10-29
1999-06-08
Renner, Craig A.
Dynamic magnetic information storage or retrieval
Record transport with head stationary during transducing
Drum record
G11B 2121
Patent
active
059108657
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to disc drive storage systems and, more particularly, to a disc head slider having rails with trailing edge cuts.
Disc drives of the "Winchester" type are well known in the industry. Such drives use rigid discs coated with a magnetizable medium for storage of digital information in a plurality of circular, concentric data tracks. The discs are mounted on a spindle motor which causes the discs to spin and the surfaces of the discs to pass under respective hydrodynamic (e.g. air) bearing disc head sliders. The sliders carry transducers which write information to and read information from the disc surfaces. An actuator mechanism moves the sliders from track to track across the surfaces of the discs under control of electronic circuitry. The actuator mechanism includes a track accessing arm and a suspension for each head gimbal assembly. The suspension includes a load beam and a gimbal. The load beam provides a preload force which forces the slider toward the disc surface. The gimbal is positioned between the slider and the load beam to provide a resilient connection that allows the slider to pitch and roll while following the topography of the disc. The slider includes an air bearing surface which faces the disc surface.
There are generally two types of sliders, positive pressure air bearing (PPAB) sliders and self-loading or "negative pressure" air bearing (NPAB) sliders. An NPAB slider typically has a pair of rails extending along the sides of the bearing, with a cavity dam extending between the rails near the leading end of the slider. As the disc rotates, the surface of the disc drags air under the cavity dam by viscous friction exerted by the disc surface. As the air passes over the cavity dam, the air expands into a "cavity" between the rails, which forms a partial vacuum in the cavity. The partial vacuum draws the slider closer to the disc surface and counteracts positive pressure developed along the rails. The cavity is open to atmospheric pressure at the trailing end of the slider, and may also include a center rail or an island at the trailing end of the slider to mount a single recording head. NPAB surfaces have many advantages, such as reduced take off and landing velocity during spindle start up and shut down, high bearing stiffness and lower sensitivity of flying height to changes in altitude and velocity, as compared to PPAB sliders having no cavity dam.
However, NPAB sliders are seldom used in ramp "load-unload" drive applications because of their high suction force. In these applications, the slider is unloaded from the disc surface by rotating the actuator mechanism until the suspension engages a ramp which lifts the suspension and thus the slider from the disc surface. The high suction force prevents an NPAB slider from following the suspension as the suspension rides up on the unloading ramp. The slider remains in close proximity to the spinning disc causing the ramp to elastically deform the suspension. The NPAB suction force breaks only when a significant elastic strain has accumulated in the suspension. The release of the suction force releases the elastic strain in the suspension and allows the slider to unload from the disc surface. This cycle of suction force and strain release occurs very rapidly relative to the time in which the suspension is in contact with the unloading ramp. The rapid release of elastic strain energy sets up vibratory oscillations in the slider position coordinate that is normal to the plane of the disc surface. These oscillations may be large enough to cause the slider to "slap" against the disc surface, thereby generating wear debris particles and possibly damaging the recording head.
Another problem observed with NPAB sliders during unloading occurs in the event that the unloading force exerted by the deformed suspension is too small to overcome the suction force. In this event, the suction force is broken when the slider is swung over the disc perimeter, allowing the atmosphere to flow into the cavit
REFERENCES:
patent: 4673996 (1987-06-01), White
patent: 4734803 (1988-03-01), Nishihira
patent: 4894740 (1990-01-01), Chhabra et al.
patent: 5062017 (1991-10-01), Strom et al.
patent: 5212608 (1993-05-01), Yoneoka
patent: 5267104 (1993-11-01), Albrecht et al.
patent: 5267109 (1993-11-01), Chapin et al.
patent: 5274518 (1993-12-01), Chapin et al.
patent: 5343343 (1994-08-01), Chapin
patent: 5396387 (1995-03-01), Murray
patent: 5406432 (1995-04-01), Murray
patent: 5430591 (1995-07-01), Takeuchi et al.
patent: 5473485 (1995-12-01), Leung et al.
patent: 5488524 (1996-01-01), Cunningham
patent: 5490025 (1996-02-01), Dorius et al.
patent: 5513056 (1996-04-01), Kawasaki et al.
patent: 5515219 (1996-05-01), Ihrke et al.
patent: 5550692 (1996-08-01), Crane
patent: 5685645 (1997-11-01), Nepela et al.
patent: 5721650 (1998-02-01), Crane et al.
patent: 5739981 (1998-04-01), Cha et al.
"IBM H-2344-A4 Disc Drive", Xerographic copy of photograph, Dec. 1993.
Research Disclosure 25946, "Roll Insensitive Slider Design for Improved Disk File Reliability", Disclosed anonymously, Nov. 1985.
Crane Peter
Wang Ling
Zhang Lei
Renner Craig A.
Seagate Technology Inc.
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