Dynamic magnetic information storage or retrieval – Head mounting – For moving head into/out of transducing position
Reexamination Certificate
1998-09-22
2001-01-30
Klimowicz, William (Department: 2754)
Dynamic magnetic information storage or retrieval
Head mounting
For moving head into/out of transducing position
Reexamination Certificate
active
06181529
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a suspension for supporting a head section of a disk drive stored in an information processing apparatus such as a personal computer, and more particularly, to an improvement of a suspension end portion.
A head section of a magnetic disk drive or the like that uses a hard disk includes a slider. Data are recorded in or retrieved from the disk by means of a transducer that is stored in the slider. The slider is supported by a suspension in a manner such that it can be lifted above the surface of the disk.
Conventionally, disk drives of this type are provided with means for evacuating the slider to a region outside the tracks of the disk when the disk is stopped from rotating. CSS (contact-start-stop) and L/UN (loading/unloading) systems are known examples of this evacuating means.
In the CSS system, the distal end portion of the suspension is moved to the inner peripheral portion of the disk when the disk is stopped. In order to prevent the slider from clinging to the surface of the stopped disk, according to the CSS system, the surface of the inner peripheral portion of the disk is roughened to a certain degree. Accordingly, the inner peripheral portion of the disk cannot be used as a recording area (tracks), so that the disk cannot enjoy a satisfactory recording capacity. The recording capacity may be increased by reducing the fly height of the slider, for example. According to the CSS system, however, the rough surface of the inner peripheral portion of the disk prevents the reduction of the fly height.
In the L/UN system or ramp-load system, on the other hand, a plastic ramp block is disposed beside the disk. When the disk is stopped from rotating, the suspension moves to a refuge zone beside the disk so that its distal end portion runs on the ramp block. Thereupon, the suspension is supported by the ramp block. This L/UN system does not require the surface of the inner peripheral portion of the disk to be roughened. Therefore, the fly height can be reduced, and the recording capacity can be made greater than in the case of the CSS system. According to the L/UN system, moreover, the inner peripheral portion of the disk can be also used as a recording area, thus facilitating augmentation of the capacity.
In the loading/unloading system, however, the contact between the suspension and the ramp block involves some problems. As the suspension repeatedly touches and leaves the ramp block, for example, a part of the plastic ramp block may be shaved, thereby producing fine contaminants. As the coefficient of friction between the suspension and the ramp block changes with time, moreover, control of the suspension may become difficult in some cases. Since the friction coefficient of the contact region between the suspension and the ramp block changes, furthermore, driving power for the movement of the suspension on the ramp block may become unstable.
BRIEF SUMMARY OF THE INVENTION
Accordingly, the object of the present invention is to provide a suspension for disk drive, capable of avoiding problems that are involved in contact between the suspension and a support member such as a ramp block, and a method for working the same.
In order to achieve the above object, a suspension according to the present invention comprises a loading/ unloading lug extending in the axial direction of a suspension body from the distal end portion of the suspension body and adapted to run on a support member when the suspension body is moved to a refuge zone beside a disk. The cross section of the loading/ unloading lug perpendicular to the axis of the suspension body is arcuate so that the surface in contact with the support member is convex. The outer surface of the lug forms a smoothed surface smoothed by coining.
According to the present invention, the support member can be prevented from being shaved by the loading/unloading lug in contact therewith, and there is no possibility of fine contaminants being produced or the coefficient of friction between the support member and the lug changing. Thus, the suspension can be easily controlled without entailing any change in shape of the support member, so that the loading and unloading operations of the suspension with respect to the support member are stable. Moreover, necessary driving power for the movement of the suspension on the support member is low and stable.
Preferably, the loading/unloading lug has a ridgeline extending in the axial direction of the suspension body such that the cross section of the lug perpendicular to the ridgeline is arcuate, and is embossed or bead-shaped so that the lug rises integrally with a part of the suspension body, at least the outer surface of the lug forming the smoothed surface. With the part of the suspension body thus rising integrally with the lug, the strength of the lug against bending load thereon can be improved effectively. With use of the loading/unloading lug having this shape, moreover, pressure on the contact surface of the lug on the support member can be lowered, and the support member can be restrained more effectively from being shaved.
The arithmetic mean roughness of the smoothed surface preferably ranges from 0.01 &mgr;m to less than 0.2 &mgr;m. With the surface roughness adjusted in this manner, the aforesaid object of the invention can be securely achieved by using feasible dies for coining.
A manufacturing method for the suspension according to the present invention comprises pressing a metal sheet, a material of the suspension body, by means of a die, thereby forming the metal sheet, and coining the loading/unloading lug in the thickness direction by means of a coining die having a smooth surface, thereby smoothing the outer surface of the lug and improving the strength of the lug.
According to the manufacturing method of the invention, the lug is coined as the suspension body is pressed into a given shape, so that smoothing the outer surface of the loading/unloading lug does not require use of any additional processes or equipment. Thus, the processes can be controlled with ease, and the costs can be lowered.
Coining the lug not only smoothes its outer surface but also allows its strength to be improved by work hardening and as its metallic structure is compacted by forging. Thus, the lug and its surroundings can be improved in durability. Since the lug has an arcuately raised sectional shape that is resistant to bending force, moreover, it cannot be easily deformed when it runs on the support member.
Possibly, the surface of the loading/unloading lug may be smoothed by surface treatment, such as electropolishing or coating. However, electropolishing and coating require a separate process for shaping the suspension body, besides a process for pressing it, thus entailing higher costs and laborious process control. According to the present invention, therefore, the surface roughness of the lug is improved by the coining operation that can be carried out simultaneously with the process for pressing the suspension body.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
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IBM Technical Disclosure Bulletin, “Suspension Assembly with Corn Shape Load/Unload Tab”
Aoyagi Akihiko
Kamisaku Takeshi
Otake Kazuhiko
Suzuki Hitoshi
Frishauf, Holtz Goodman, Langer & Chick, P.C.
Klimowicz William
NHK Spring Co. Ltd.
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