(1) Technical Field
The present invention relates generally to hard disc drives (HDD), and more particularly to improving ramp load/unload apparatus involving a mechanism for safely positioning read/write heads.
(2) Description of the Prior Art
Present-day mass produced hard disc drives consists of a metallic housing in which is contained one or more discs (platters) mounted on a spindle that allows the discs to rotate. The discs are made from a solid, non-magnetic material, normally aluminum or glass. The discs are coated, on each side, with a very thin layer of magnetic material into which information is stored in binary form. For both sides of each disc there is a read/write head mounted on a suspension arm that moves across the surfaces of each disc.
Typically, HDDs employ a rotary actuator structure to position the suspension arm(s) transducer heads relative to recording surfaces of rotating discs. The discs are spun at high speed that spins the air creating an “air bearing effect” on the disc surface enabling an aerodynamically shaped read/write head to “float” at a very controlled gap from the magnetic surface of the platter. This gap is extremely small, measuring less than the diameter of a human hair. Assembly of many precision made mechanical parts along with the construction of hard discs is done in a clean room and humidity-controlled environment to prevent contamination that may cause very serious damage to the hard disc.
For the past several years, data storage methods have followed a tendency of escalating storage capacity while also shrinking the physical size occupied by its storage capacities. Introduction of more powerful computer hardware and software has contributed to increasing market pressures for less expensive, larger capacity and smaller packaging in disc drives. Storage device manufacturers make every effort to achieve any possible incremental cost savings that can be reasonably achieved without loss of technical performance and reliability.
HDDs, of the prior art, using a ramp, involve a mechanism which moves the sliders off the discs prior to power-down, and safely positions them onto a cam-like structure. The cam is equipped with a shallow ramp on the side closest to the disc, giving ramp load/unload its name. During a power-on sequence, the read/write heads are loaded by moving the sliders off the ramp, and over the disc surfaces when the discs reach the appropriate rotational speed. The air current from the rotating disc acts like an air cushion between the sliders and discs, keeping the two surfaces separated by a designed distance, called the flying height.
Conventionally, installed ramps are on the base of the metallic housing. The ramps either slide or rotate into position over the surfaces of each disc. This action requires a precision-machined reference surface, a locating stop and a securing feature in the base. Additionally, HDDs using a latch to prevent the read/write heads from moving onto platter surfaces during shipping or non-operating situations, are installed on the base keeping the actuator in a secure position in the event of inappropriate handling. This also requires a precise machined mounting surface, locating stop and a securing feature on the base. Lastly, a flexible printed circuit (FPC) used to transfer data from a read/write head to a printed circuit board (PCB). A connector is used to electrically join the PCB that is mounted outside the sealed disc drive to the FPC, which is attached to the read/write heads inside the sealed disc drive. A gasket provided to seal the connector, and a bracket to locate and compress the gasket. This also requires a precise machined mounting surface, locating features and a securing feature in the base. Conventionally, the ramp, latch and connector bracket are three separate members attached and positioned independently onto the base structure.
Traditionally, hard disk drives that use a ramp will load the read/write heads from the backside of the ramp opposite the disc side. This action requires additional travel to the backside of the ramp for loading the actuator assembly. Because of the additional travel, the coil side of the actuator is made smaller to allow clearance for installing discs. The smaller coil size affects efficiency of the actuator. During disc loading, the actuator must be held off the ramp. After loading the discs, the ramp is then positioned over the disc, the head separator comb removed, and the actuator loaded onto the ramp. The stop for the outside diameter position is then installed after the actuator is loaded on the ramp. With all this activity, exposure to disc damage is a real possibility that would necessitate the entire disc drive to be reworked.
An object of the present invention is to provide an improved ramp device for parking read/write heads in hard disc drives. The improvement permitting loading the heads from the front side of the ramp thereby reducing head travel during loading while yielding more space on the coil side to provide more room for a more efficient voice coil motor. Moreover, the outside diameter stop can be put into place before the actuator and discs are installed. The actuator can also be placed on the ramp while in the park position, and the head comb removed before the discs are installed. The only remaining action required after disc installation is to rotate and to secure the ramp in position to reduce possible disc damage.
Another object of the present invention is to provide a ramp with a rotational pivot aligned to the head's actuator pivot while in the parked position.
Still another object of the present invention is to continue the ramp's park position, rotationally, on the same radius allowing the read/write heads to be installed from the front (disc) side.
Yet another object of the present invention is to reduce disc damage and to make the assembly tooling less complicated.
Still another object of the present invention is to fixably attach the outside diameter stop to the base for more accurate positioning.
A novel application of geometric design principles is at the center of the present invention. Applying these, principles while integrating parts serve the assembly and improve reliability for the hard disc drive.
The foregoing, together with other object features and advantages of this invention, can be better appreciated with reference to the following specification, claims, and the accompanying drawings.
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In summary, a method is provided for loading read/write heads, mounted on pivotal actuator arms, onto ramps from the front side of a hard disc drive including the steps of providing a bracket having a ramp pivot bearing for demountably attaching a ramp platform to the bracket and aligning the ramp pivot bearing to the actuator arm pivot, the bracket also having pivoting stops for a ramp locator arm for stopping the ramp in its open and closed positions also providing an extended ramp park position by extending the parking surface angularly around the ramp pivot on the same radius.
The apparatus includes a ramp arrangement to facilitate read/write heads mounted on actuators, to be loaded at the front side in a hard disc drive, the ramp arrangement is composed of a movable ramp to be in either an open or a closed position with a design that has surfaces for ramping, parking and extended parking areas that are selectable for various assembly and disassembly activities. The movable ramp includes a pivot post for pivoting and a locator arm for limiting movement within the open and closed positions. A ramp bracket mounted to a base of a hard disc drive, the bracket having a pivot bearing for demountable attaching the ramp post to the bracket and aligning the ramp pivot bearing to a pivot of the actuator, the bracket also having pivoting stops for the ramp locator arm for stopping the ramp in its open and closed positions;
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.