Patent Publication Number: US-7222411-B1

Title: Method of interconnecting a load/unload ramp assembly with a base plate of a disk drive

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application is a divisional of and claims priority under 35 U.S.C. § 120 to U.S. patent application Ser. No. 10/027,907, now U.S. Pat. No. 6,927,943 that was filed on Dec. 21, 2001, and that is entitled “ATTACHMENT METHOD AND APPARATUS FOR LOAD/UNLOAD RAMP OF A DYNAMIC LOAD DISK DRIVE”, and further claims priority from U.S. Patent Application Ser. No. 60/269,760, that was filed on Feb. 16, 2001, and that is entitled a “ATTACHMENT METHOD FOR LOAD/UNLOAD RAMP.” The entire disclosures of both U.S. Patent Application Ser. No. 60/269,760 and U.S. patent application Ser. No. 10/027,907 are incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to dynamic load/unload-type disk drives and, more particularly, to the manner of interconnecting a load/unload ramp with a base plate of the disk drive. 
     BACKGROUND OF THE INVENTION 
     Conventional dynamic load/unload-type disk drives typically include a base plate and a cover that is detachably connected to the base plate to define a housing for various disk drive components. One or more data storage disks are generally mounted on a spindle which is interconnected with the base plate and/or cover so as to allow the data storage disk(s) to rotate relative to both the base plate and cover via a spindle motor. An actuator arm assembly (e.g., a single rigid actuator arm, a plurality of rigid actuator arms, an E-block with a plurality of rigid actuator arm tips), is interconnected with the base plate and/or cover so as to allow the actuator arm assembly to move relative to both the base plate and cover in a controlled manner. This motion is either typically a pivoting or a linear motion. 
     A suspension or load beam may be provided for each data storage surface of each data storage disk. Typically each disk has two of such surfaces. All suspensions are appropriately attached to and extend away from the actuator arm assembly in the general direction of the data storage disk(s) during normal operations. A transducer, such as a read/write head, is carried by a slider that is disposed on the free end of each suspension. Signals are exchanged between the head and the corresponding data storage disk to read and/or write information. The position of the actuator arm assembly, and thereby each transducer, is controlled by a voice coil motor or the like which moves the actuator arm assembly to dispose the head(s) at the desired radial position relative to the corresponding data storage disk. 
     The head(s) of the disk drive is parked off its corresponding data storage disk by using a load/unload ramp. The load/unload ramp is typically disposed at least toward (and possibly beyond) the perimeter of the corresponding data storage disk. Load/unload ramps may be made from plastic to reduce material costs, and are nonetheless attached to the base plate. It is desirable to have the load/unload ramp demonstrate good wear characteristics as the suspension/slider moves along the ramp. Moreover, it is desirable for the load/unload ramp to tolerate the increased temperatures that exist within the disk drive housing during disk drive operations. Certain plastics may have a tendency to creep at these temperatures, particularly over those areas of the load/unload ramp that are stressed by the attachment of the load/unload ramp to the base plate. “Creeping” refers to a progressive deformation over a period of time due to a material being under a constant load or stress. This time dependent deformation has proven to be a limiting factor in the operational integrity of at least certain designs of load/unload ramps that are formed from plastic. 
     Creeping of a plastic load/unload ramp may have a number of undesired effects. For example, if the plastic load/unload ramp is attached to the base plate using a screw, over time, creeping of the ramp plastic may loosen the screw and result in the screw failing to adequately secure the load/unload ramp to the base plate. This problem has been addressed in a number of ways. A common practice to combat creeping has included insert-molding a metal plate into the plastic load/unload ramp to increase the integrity of the attachment of the ramp to the base plate. However, this addition of a metal plate to the load/unload ramp can more than double the cost of producing such ramps. Another attempt at solving the problem of creeping reflects using a screw in combination with locking devices to attach the plastic load/unload ramp to the base plate. However, locking devices such as thread locks not only add cost, but also add the risk of outgassing (i.e., the vaporization of materials from one or more surfaces of the thread locks after they are placed in low pressure environments during disk drive operations). Further, locking devices such as lock-washers add cost, create particulates, and may require a more expensive grade of ramp plastic for compatible use. While suitable plastics with improved creep characteristics are known, they are significantly more expensive than even the attempted improved attachment methods. Therefore, it would be desirable to have a load/unload ramp of a configuration that reduces manufacturing costs, provides a use-life that is greater than that of conventional ramps, and/or that reduces the effect of creep in relation to the attachment of the load/unload ramp to the base plate. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to dynamic load/unload-type disk drives. More specifically, the present invention is generally directed to a load/unload ramp assembly for use with a compatible base plate of a dynamic load/unload-type disk drive, which may utilize one or more heads/data storage disks. That is, the present invention is equally applicable to single and multiple head disk drive configurations. The design/configuration of the load/unload ramp assembly of the present invention desirably addresses the interconnection of the load/unload ramp assembly to the base plate in a manner that is not significantly adversely affected by the elevated temperatures that exist within the disk drive housing during disk drive operations. Accordingly, the design/configuration of any appropriate dynamic load/unload-type disk drive may benefit from the installation of a load/unload ramp assembly of the present invention in a manner that will now be described. 
     Generally, the present invention is embodied in a load/unload ramp assembly that has at least one deflectable member that is deflected toward an underlying portion of a base plate to force the load/unload ramp assembly into engagement with the base plate. That is, any such deflectable member will initially be spaced from an underlying portion of the base plate, and then deflected toward the base plate to force the load/unload ramp assembly into engagement with the base plate. Typically, this deflection will be accomplished using one or more appropriate fasteners. Any appropriate configuration may be used for each deflectable member of the noted type. Therefore, although the present invention is hereafter described in relation to this deflectable member being a “base plate attachment cantilever,” other types of deflectable members could be substituted therefore. For instance, another example of an appropriate configuration for a deflectable member that is encompassed by the present invention is a simple beam structure that is supported at two spaced locations. 
     A first aspect of the present invention is embodied by a load/unload ramp assembly that is interconnectable with a base plate of a disk drive. The load/unload ramp assembly generally has a ramp body that includes a load/unload ramp and at least one base plate attachment cantilever that may be deflected at least generally toward the base plate when engaged by at least one appropriate fastener. This deflection of the base plate attachment cantilever(s) forcibly engages the load/unload ramp assembly with the base plate to appropriately interconnect the same. 
     Various refinements exist regarding the features noted in relation to the subject first aspect of the present invention. Additional features may also be incorporated in the subject first aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. The load/unload ramp assembly of the first aspect may be utilized with any base plate configuration that allows the load/unload ramp assembly to be secured thereto by a deflection of at least one base plate attachment cantilever. Typically, each fastener that is used to secure the load/unload ramp assembly to this base plate will have a corresponding fastener receptacle that is formed on a surface of the base plate that projects toward the load/unload ramp assembly when installed thereon. This base plate may include a number of additional features, which will be discussed in more detail below in relation to the second aspect. 
     Preferably, at least two base plate attachment cantilevers are utilized by the first aspect, and such will be referred to as first and second base plate attachment cantilevers. Characteristics of these first and second base plate attachment cantilevers that are hereafter described in relation to the first aspect may be utilized by each base plate attachment cantilever utilized by the first aspect, including where only a single base plate attachment cantilever is utilized by the first aspect. The first and second base plate attachment cantilevers may extend at least generally toward each other or a common point, and have respective first and second free ends. These first and second free ends may be disposed in spaced relation to generally define at least a portion of a fastener aperture so that a shaft of a fastener can pass by/between the first and second free ends. Additionally, the spaced relation of the first and second free ends of the first and second base plate attachment cantilevers makes it possible for the head of the fastener to simultaneously exert a force on the first and second base plate attachment cantilevers. It should be appreciated that side portions of the first and second base plate attachment cantilevers could also be disposed in space relation so as to allow a fastener to pass therebetween. In any case, upon the load/unload ramp assembly being installed on the base plate and the head of a particular fastener exerting a force on at least the first and second base plate attachment cantilevers, these first and second base plate attachment cantilevers are generally deflected toward the base plate to forcibly engage the load/unload ramp assembly with the base plate, and thereby to secure the load/unload ramp assembly to the base plate. 
     The first and second base plate attachment cantilevers that may be associated with the first aspect may be generally disposed in opposing relation. In other words, the first base plate attachment cantilever may be positioned at or define a first portion of a fastener aperture, and the second base plate attachment cantilever may be positioned at or define a second portion of this fastener aperture that is directly opposite the first portion. The ramp body can have at least one aperture shelf positioned about the fastener aperture and recessed relative to an upper surface of each base plate attachment cantilever. Some variations of the first aspect include both the first and second base plate attachment cantilevers and first and second aperture shelves. In such variations, the first and second base plate attachment cantilevers may be positioned in opposing relation, and the first and second aperture shelves may be disposed in opposing relation. In one embodiment, a reference line connecting the first and second base plate attachment cantilevers is generally perpendicular to a reference line connecting the first and second aperture shelves. Preferably, the intersection point of these two reference lines generally corresponds with a central portion of the fastener aperture of the load/unload ramp assembly. 
     Multiple base plate attachment cantilevers may be utilized in any manner in relation to the first aspect (e.g., arranged in variety of configurations). For instance, multiple base plate attachment cantilevers may be utilized without collectively defining a fastener aperture therebetween. For instance, each base plate attachment cantilever could be deflected by its own fastener(s). That is, each base plate attachment cantilever may have its own fastener or set of fasteners. However and as noted above, a particular fastener may simultaneously act on multiple base plate attachment cantilevers. Any combination of base plate attachment cantilevers and fasteners may be used in relation to the first aspect. What is of importance is that any fastener that is utilized by the first aspect to engage the load/unload ramp assembly against the base plate does so by deflecting one or more base plate attachment cantilevers toward the base plate. 
     Any base plate attachment cantilever that is utilized by the first aspect may be arranged in any appropriate fashion on the load/unload ramp assembly. For instance, a given base plate attachment cantilever may be disposed interiorly of a perimeter of the load/unload ramp assembly. Moreover, a given base plate attachment cantilever may be disposed on a perimeter of the load/unload ramp assembly for deflection by an appropriate fastener(s). The shaft of this fastener could extend through the load/unload ramp assembly, or could be disposed beyond the load/unload ramp assembly, so long as part of this fastener could still engage at least one base plate attachment cantilever to deflect the same in the manner described herein. 
     Any of the base plate attachment cantilevers that may be associated with the first aspect can each include one or more fastener head contact protrusions or pads that are positioned on the upper surface of the corresponding base plate attachment cantilever. In variations having such fastener head contact protrusions, each fastener head contact protrusion may be positioned at least generally at a free end of the corresponding base plate attachment cantilever. In other words, since a “cantilever” generally refers to a projecting structure that is attached or supported at only one end, each fastener head contact protrusion may be generally disposed at an end of the respective attachment cantilever which is substantially free from attachment to and/or support from the ramp body. However, it should be appreciated that any such fastener head contact protrusion may be disposed anywhere on the corresponding base plate attachment cantilever for engagement by the corresponding fastener(s). Preferably, a given base plate attachment cantilever has a pair of the noted fastener head contact protrusions so as to “cradle” the head of the fastener that is engaged therewith to attach the load/unload ramp assembly to the disk drive base plate. In variations of this first aspect which include such fastener head contact protrusions, these fastener head contact protrusions are ideally positioned on the corresponding base plate attachment cantilever so as to distribute the axial force of the fastener to locations on the respective base plate attachment cantilevers that cause minimum physical distortion of the load/unload ramp assembly. 
     In one embodiment of the first aspect, a major axis of a given base plate attachment cantilever is disposed at an angle relative to horizontal prior to being engaged by the base plate attachment fastener. That is, the free end of a given base plate attachment cantilever may be disposed at a higher elevation than its corresponding fixed end. In addition, a given base plate attachment cantilever may have a lower surface that extends at least generally upwardly progressing toward its corresponding free end. Stated another way, in one embodiment of the first aspect, an upper surface of a given base plate attachment cantilever is disposed in non-parallel relation with a corresponding lower surface of the base plate attachment cantilever. Features, such as serrations or the like, may be formed on the lower surface of each base plate cantilever to enhance the engagement with the underlying disk drive base plate when attached thereto. 
     A second aspect of the present invention includes a disk drive having a base plate, a load/unload ramp assembly of the type discussed above in relation to the first aspect, and at least one fastener that secures this load/unload ramp assembly to the base plate. The base plate generally has a first surface and preferably at least one boss (that is, a boss is not required by the second aspect). Each boss projects away from the first surface, and at least one fastener receptacle is formed in the base plate (on/through a corresponding boss when utilized by the second aspect). A fastener is typically provided for each fastener receptacle and includes a head and a shaft. The shaft of each fastener extends past at least one base plate attachment cantilever (for example, an end thereof; a side thereof) and is generally securely disposed within a corresponding fastener receptacle of the base plate. Accordingly, the head of each fastener exerts a force on at least one base plate attachment cantilever to deflect each base plate attachment cantilever engaged thereby toward the underlying base plate. This deflection of each base plate attachment cantilever forces a bottom surface of the load/unload ramp assembly into engagement with the first surface of the base plate to establish a secure interconnection between the load/unload ramp assembly and the base plate. 
     Various refinements exist regarding the features noted in relation to the subject second aspect of the present invention. Additional features may also be incorporated in the subject second aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. Initially, each of the various features discussed above in relation to the first aspect of the present invention of the load/unload ramp assembly may be incorporated into this second aspect of the invention as well, alone or in any combination. Additional features in relation to the base plate may also be utilized by the second aspect. The base plate can include first and second mounting pads disposed on the first surface of the base plate. These first and second mounting pads may be generally recessed relative to a given boss of the base plate (i.e., disposed at a lower elevation). In other words, a given boss of the base plate may extend out and away from the first surface of the base plate a greater distance than its corresponding first and second mounting pads extend from the first surface of the base plate. In one embodiment, the first and second mounting pads are disposed in opposing relation. In another embodiment, the first and second mounting pads may be positioned on the first surface of the base plate so that a given boss of the base plate is positioned directly between the first and second mounting pads. In yet another embodiment, the first and second mounting pads may be generally disposed so that a reference line connecting the first and second mounting pads is perpendicular to a reference line connecting first and second base plate attachment cantilevers that may be utilized by the load/unload ramp assembly in relation to the second aspect. 
     In variations of the second aspect in which the ramp body of the load/unload ramp assembly incorporates at least one aperture shelf positioned about each fastener receptacle on the base plate, the aperture shelf/shelves preferably overlay(s) at least one of the corresponding first and second mounting pads. While the aperture shelf/shelves are positioned about the corresponding fastener receptacle, some amount of clearance preferably exists between the shaft of the fastener (that also extends into the fastener receptacle) and the corresponding aperture shelf/shelves. In other words, the head of a given fastener preferably does not interface with the corresponding aperture shelf/shelves when the load/unload ramp assembly is in an installed position. However, embodiments are contemplated wherein one both of the head and the shaft of the fastener can interface with the corresponding aperture shelf/shelves. 
     Ideally, the only contact between the first surface of the base plate and the bottom surface of the load/unload ramp assembly in the case of the second aspect (ignoring any contact via any alignment posts and corresponding alignment holes that may be utilized and that are discussed in more detail below) is between each mounting pad utilized by the base plate and a corresponding portion of the bottom surface of the load/unload ramp assembly. In other words, excluding the contact exhibited via the alignment posts, the bottom surface of the load/unload ramp assembly is preferably free from direct contact with any other portion of the first surface of the base plate other than the noted mounting pads. 
     In some variations of the second aspect of the present invention, the base plate has at least one alignment hole. Preferably, the base plate has first and second alignment holes, with a given boss of the base plate being positioned between the first and second alignment holes. Thus, the base plate can have first and second alignment holes positioned on opposite sides of a given boss of the base plate and first and second mounting pads positioned on opposite sides of such a boss of the base plate, so that a first reference line connecting the first and second alignment holes is substantially perpendicular to a second reference line connecting the first and second mounting pads. Preferably, the intersection point of these two lines generally corresponds with a central portion of the fastener receptacle of this boss of the base plate. The bottom surface of the load/unload ramp assembly can have at least one alignment post configured to fit into the complimentarily shaped alignment hole(s) of the base plate. Thus, upon installation of the load/unload ramp assembly onto the base plate, the alignment post(s) of the load/unload assembly can be disposed within the respective alignment hole(s) of the base plate to prevent sliding and/or rotational movement of the load/unload ramp assembly in relation to the base plate. Generally, each alignment post may have a circular, elliptical, or quadrilateral cross-sectional configuration, although other appropriate cross-sectional configurations are contemplated. In some variations of the invention, the bottom surface of the load/unload ramp assembly can include the alignment hole(s), and the base plate can include the corresponding alignment pin(s). Any way of maintaining alignment of the load/unload ramp assembly on the base plate may be utilized. 
     The shaft of each fastener associated with the second aspect may be threaded so as to be engaged with complimentarily threaded walls of the fastener receptacle of a given boss of the base plate. In one embodiment, a given base plate attachment cantilever is sufficiently spaced from a corresponding mounting boss and this boss is sufficiently sized such that the shaft of the fastener may be moved within the fastener receptacle to deflect the corresponding base plate attachment cantilever(s) until the head of the fastener engages an upper surface of the corresponding boss. Stated another way, in an installed position, the head of a given fastener may have a lower surface which is seated on the upper surface of a corresponding boss of the base plate, while at the same time having engaged the corresponding base plate attachment cantilever(s) so as to deflect the load/unload ramp assembly into forcible engagement with the underlying base plate. In other words, once installed, the lower surface of a given fastener head is in direct communication/engagement with the upper surface of the corresponding boss of the base plate. This allows a given fastener to exert a significant load on the base plate (by engaging a corresponding boss), while at the same time exerting a smaller (and more preferably a significantly smaller) load on each of the base plate attachment cantilevers that is engaged by the head of this fastener. 
     Any fastener associated with the second aspect and continuing with the foregoing (preferably via the lower surface of the head) may exert an axial force within a range of about 25 pounds up to about 400 pounds, and more preferably about 100 pounds up to about 200 pounds, on the upper surface of the corresponding boss of the base plate. In addition to affecting a force on at least the upper surface of the corresponding boss, the lower surface of the fastener head generally deflects each of the base plate attachment cantilever(s) engaged thereby so as to dispose the load/unload ramp assembly into forcible engagement with underlying portions of the first surface of the base plate as noted above. This deflection of each of the base plate attachment cantilevers again is generally in response to the shaft of the corresponding fastener being moved further within the fastener receptacle and a resulting engagement of the head of the fastener against deflectable portions of the base plate cantilevers that are associated with the particular fastener. In one embodiment, in an installed position, each base plate attachment cantilever generally deflects from about 4 mils to about 8 mils due to the force exerted by the head of the fastener. However, embodiments are contemplated in which the base plate attachment cantilever(s) exhibit deflection levels which fall outside the range of about 4 mils to about 8 mils. Generally, this axial force exerted on the base plate attachment cantilever(s) of the load/unload ramp assembly may be within a range of about 1 pound up to about 10 pounds, and yet maintain a sufficient interconnection between the load/unload ramp assembly and the base plate. Variations of the subject second aspect are also contemplated which exhibit axial forces outside the above-described ranges. Thus, the axial force that is exerted on the boss of the base plate may be generally greater, and preferably significantly greater, than the axial force that is exerted on each of the base plate attachment cantilever(s) as noted above. 
     A third aspect of the present invention is embodied in a disk drive having a load/unload ramp assembly disposed on a base plate of the disk drive. The load/unload ramp assembly has a ramp body that generally includes a load/unload ramp and at least one base plate attachment cantilever. This base plate attachment cantilever can have a first fixed end and a first free end. The load/unload assembly is affixed to the base plate of the disk drive utilizing at least one fastener having a head and a shaft. The shaft of a particular fastener generally extends past at least one base plate attachment cantilever of the load/unload ramp assembly and is securely disposed within a fastener receptacle of the base plate such that the head of the fastener exerts a force on an appropriate portion of the corresponding base plate attachment cantilever(s) to deflect this base plate attachment cantilever(s) toward the base plate, to in turn force a bottom surface of the load/unload ramp assembly into engagement with the base plate. 
     Various refinements exist regarding the features noted in relation to the subject third aspect of the present invention. Additional features may also be incorporated in the subject third aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. Generally, each of the various features discussed in relation to any of the aspects of the present invention may be incorporated into this third aspect, alone or in any combination. 
     A fourth aspect of the present invention is embodied by a method of interconnecting a load/unload ramp assembly with a base plate of a disk drive. The method first includes disposing the load/unload ramp assembly on the base plate. A shaft of a fastener engages at least one base plate attachment cantilever of the load/unload ramp assembly and is directed into a fastener receptacle on the base plate. Prior to “loading” the base plate cantilever(s) with the fastener, at least a portion of a lower surface of each base plate attachment cantilever to be engaged by this fastener is spaced from an underlying portion of the base plate. The method additionally includes moving the shaft of the fastener further within the fastener receptacle and deflecting any base plate attachment cantilever engaged by the fastener such that a lower surface of the load/unload ramp assembly is directed into forcible engagement with an underlying portion of the base plate. 
     Various refinements exist regarding the features noted in relation to the subject fourth aspect of the present invention. Additional features may also be incorporated in the subject fourth aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. Generally, each of the various features discussed above in relation to the first, second, and third aspects of the present invention may be incorporated into this fourth aspect, alone or in any combination. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top view of one embodiment of a disk drive with a cover plate having been removed. 
         FIG. 2  is a magnified perspective view of the disk drive of  FIG. 1  with the data storage disk removed. 
         FIG. 3  is a perspective view illustrating a top portion of the load/unload ramp assembly used by the disk drive of  FIG. 1 . 
         FIG. 4  is a perspective view showing a bottom portion of the load/unload ramp assembly used by the disk drive of  FIG. 1 . 
         FIG. 5  is a perspective view of a portion of the base plate used by the disk drive of  FIG. 1  and that is configured to receive the load/unload ramp assembly of  FIGS. 3-4 . 
         FIG. 6  is a top view of the load/unload ramp assembly of  FIGS. 3-4 , illustrating how the load/unload ramp assembly relates to mounting pads of the base plate of  FIG. 5  that are positioned beneath the load/unload ramp assembly. 
         FIG. 7  is a cross-sectional view of the load/unload ramp assembly of  FIGS. 3-4  wherein mounted on the base plate of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described in relation to the accompanying drawings, which at least assist in illustrating the various pertinent features thereof.  FIGS. 1 and 2  illustrate various components of one embodiment of a disk drive  10  that generally includes a base plate  11  having a first surface  13 . A cover (not shown) is typically disposed atop the base plate  11  and is detachably attached thereto to define an enclosed space for the various disk drive components. The disk drive  10  further includes a data storage disk  14  of any appropriate computer-readable data storage media. However, the data storage disk  14  of disk drive  10  has been removed to show various other disk drive components; accordingly, the data storage disk  14  is shown in dashed outline only in  FIG. 1 , and is not illustrated in  FIG. 2 . This data storage disk  14  is generally mounted on a spindle  16 , which in turn is rotatably interconnected with the base plate  11  and/or cover of the disk drive  10 . Generally, the data storage disk  14  is made from glass, ceramic, or one or more of a variety of metals. A spindle motor  18  is coupled to the spindle  16  to spin the data storage disk  14  at an appropriate rate. 
     The disk drive  10  also includes an actuator arm assembly  20  which pivots about a pivot bearing  22 , which in turn is rotatably supported by the base plate  11  of the disk drive  10  and/or cover.  FIGS. 1 and 2  illustrate that the actuator arm assembly  20  is positioned between the base plate  11  and the data storage disk  14  (i.e., under the data storage disk  14 ). This actuator arm assembly  20  generally includes a rigid actuator arm  24  which extends out from near the pivot bearing  22  and a suspension  26  attached to an end of the actuator arm  24  most remote from the pivot bearing  22 . A head  28  is disposed at or near an end of each suspension  26 . The head  28  typically includes a body (e.g., slider) and at least one transducer (not shown) that exchanges signals with the corresponding data storage disk  14 . The head  28  is interconnected with the suspension  26  of the actuator arm assembly  20  so that the head  28  generally faces away from the base plate  11  and toward the cover (not shown) of the disk drive  10 . Stated another way, the head  28  is positioned on the actuator arm assembly  20  in such a manner as to allow the head  28  to operatively interface with a data storage surface of the data storage disk  14  that faces the base plate  11 . Accordingly, the disk drive  10  also includes a load/unload ramp assembly  40  having a load/unload ramp  44  which slopes away from the data storage disk  14  and toward the base plate  11  of the disk drive  10  so as to dispose the head  28  and its corresponding data storage disk  14  in spaced relation when the head  28  is “parked” (i.e., at the termination of disk drive operations). In the illustrated embodiment, the load/unload ramp assembly  40  is disposed under the data storage disk  14  and at least generally toward a radially inward portion thereof. 
     Additionally, a voice coil motor (VCM)  32  at least operatively interfaces with the actuator arm assembly  20  at a distal end  34  that is opposite that of the head  28 . The VCM  32  imparts motion to the actuator arm assembly  20 , and thus to the head  28  (e.g. in response to a control signal). The VCM  32  generally consists of a magnet(s) and a coil of fine wire, although other configurations are contemplated. Notwithstanding the configuration of the disk drive  10  just described, the manner of interconnecting a load/unload ramp assembly with a base plate that will now be discussed may be incorporated into any appropriate disk drive configuration. 
       FIGS. 3-4  illustrate further details of the load/unload ramp assembly  40  that is interconnectable with the base plate  11  of the disk drive  10 . The load/unload ramp assembly  40  is configured in a manner so as to allow the same to be fabricated from plastic, although other materials could be utilized. Generally, the load/unload ramp assembly  40  has a ramp body  42  that includes a load/unload ramp  44  which generally assists in separating the head  28  from contact with the data storage disk  14  when the head  28  is parked. Generally, as disk drive operations are terminated, the voice coil motor  32  pivots the actuator arm assembly  20  so as to move the head  28  toward a radially inward location on its corresponding data storage disk  14  (or at least generally toward the spindle  16 ). During this motion, the head  28  engages the load/unload ramp  44 . Continued movement of the actuator arm assembly  20  in the noted direction thereby directs the head  28  away from the data storage disk  14  and at least generally toward the base plate  11  of the disk drive  10 . Features may be incorporated into the load/unload ramp assembly  40  so as to attempt to retain the actuator arm assembly  20  in the parked position until disk drive operations are subsequently re-initiated. 
     The load/unload ramp assembly  40  generally is configured to enhance one or more aspects of its interconnection with the base plate  11 . In this regard, the load/unload ramp assembly  40  includes first and second base plate attachment cantilevers  46 ,  48 , respectively, which extend at least generally toward each other and have respective first and second free ends  47 ,  49 , and respective first and second fixed ends  51 ,  53 . Any number of base plate attachment cantilevers may be utilized by the load/unload ramp assembly  40 , including a single base plate attachment cantilever and more than two base plate attachment cantilevers. Each respective fixed end  51 ,  53  is in direct contact with the ramp body  42 . In other words, the fixed end (e.g.  51 ,  53 ) of each base plate attachment cantilever  46 ,  48  is in uninterrupted engagement with the ramp body  42 . Conversely, the respective first and second free ends  47 ,  49  of the base plate attachment cantilevers  46 ,  48  are disposed on respective opposite ends of the respective attachment cantilevers  46 ,  48 . In other words, the first fixed end  51  of the first base plate attachment cantilever  46  is disposed at an end of the cantilever  46  adjacent the ramp body  42 ; while the first free end of the first base plate attachment cantilever  46  is disposed at an end opposite that of the first fixed end  51  and most remote from any attachment to the first base plate cantilever  46 . Similarly, the second fixed end  53  of the second base plate attachment cantilever  48  is disposed at an end of the cantilever  48  adjacent the ramp body  42 ; while the second free end of the second base plate attachment cantilever  48  is disposed at an end opposite that of the second fixed end  53  and most remote from any attachment to the second base plate cantilever  48 . 
     The first and second free ends  47 ,  49  of the first and second base plate attachment cantilevers  46 ,  48 , respectively, are disposed in spaced relation to generally define a fastener aperture  50 . This fastener aperture  50  provides a space so that a shaft  54  of a fastener  52  can pass between the first and second free ends  47 ,  49  of the first and second base plate attachment cantilevers  46 ,  48 , respectively and into the base plate  11 . In other words, the fastener aperture  50  is generally an open area, at least part of which is defined between the first and second base plate attachment cantilevers  46 ,  48 . The first and second free ends  47 ,  49  of the first and second base plate attachment cantilevers  46 ,  48  are spaced apart a defined distance that enables the shaft  54  (shown in  FIG. 7 ) of the fastener  52  to pass through the at least generally round fastener aperture  50 , and yet that enables a head  56  of the fastener  52  to “catch” on or at least otherwise engage the first and second base plate attachment cantilevers  46 ,  48 , preferably at or near at least their first and second free ends  47 ,  49 , respectively, to exert a downwardly-directed force (or at least generally toward the base plate  11 ) on the first and second base plate attachment cantilevers  46 ,  48 . The first and second base plate attachment cantilevers  46 ,  48  are disposed in opposing relation so that the first base plate attachment cantilever  46  is positioned on a side of the fastener aperture  50 , and the second base plate attachment cantilever  48  is positioned on anther side of the fastener aperture  50  opposite the first base plate attachment cantilever  46 . 
     The first and second base plate attachment cantilevers  46 ,  48  each have a pair of fastener head contact protrusions  76  positioned on an upper surface  66 ,  68  of each of the first and second base plate attachment cantilevers  46 ,  48 , respectively. These fastener head contact protrusions  76  are positioned at least generally at the respective first and second free ends  47 ,  49 , respectively, of each of the first and second base plate attachment cantilevers  46 ,  48 . Each fastener head contact protrusion  76  at least generally projects out and extends away from adjacent portions of the respective upper surface  66 ,  68  of the first and second base plate attachment cantilevers  46 ,  48 . These contact protrusions  76  are illustrated as having an oblong/elliptical-type cross-sectional configuration; however other cross-sectional configurations (e.g., circular, triangular, quadrilateral) will be obvious to those of ordinary skill in the art. In an installed position, a lower surface  57  of the head  56  of the fastener  52  generally engages the fastener head contact protrusions  76  and avoids contact with the remainder of the upper surfaces  66 ,  68  of the first and second base plate attachment cantilevers  46 ,  48 . The protrusions  76  on each base plate attachment cavalier  46 ,  48  are spaced such that they engage the head  56  of the fastener  52  at two displaced locations. However, other embodiments may have only one contact protrusion  76  on each of the first and second base plate attachment cantilevers  46 ,  48 . In such embodiments, the contact protrusion could occupy entire free end (e.g.  47 ,  49 ) of each of the respective first and second base plate attachment cantilevers  46 ,  48 . Other embodiments could have more than two contact protrusions  76  on each of the first and second base plate attachment cantilevers  46 ,  48 . Yet other embodiments could have first and second base plate attachment cantilevers  46 ,  48  which are free of any fastener head contact protrusions  76 . In such embodiments, in an installed position, a lower surface  57  of the head  56  of the fastener  52  would directly engage the first and second upper surfaces  66 ,  68  of the respective first and second base plate attachment cantilevers  46 ,  48 . 
     In addition to the first and second upper surfaces  66 ,  68 , the first and second base plate attachment cantilevers  46 ,  48  have respective first and second lower surfaces  78 ,  80 . These lower surfaces  78 ,  80  are illustrated as being disposed in non-parallel relation to their corresponding upper surface  66 ,  68 , respectively to define a wedge-shaped profile or the like for the first and second base plate attachment cantilevers  46 ,  48 . That is, the thickness of the first and second base plate attachment cantilevers  46 ,  48  at their respective free ends  47 ,  49  is less than the thickness of the cantilevers  46 ,  48  at their respective fixed ends  51 ,  53 . Other configurations may be utilized for the first and second base plate attachment cantilevers  46 ,  48 . Moreover, in one embodiment the major axis of the cantilevers  46 ,  48  is disposed at an angle to the horizontal prior to engaging the fastener  52  against the cantilevers  46 ,  48 . That is, in an undeflected state and in one embodiment, the free ends  47 ,  49  of the cantilevers  46 ,  48  are disposed at a higher elevation and their corresponding fixed end  51 ,  53 . Other “static” profiles could be utilized for the cantilevers  46 ,  48 . The ramp body  42  also has first and second aperture shelves  62 ,  64 , respectively, positioned about the fastener aperture  50  and recessed relative to upper surfaces  66 ,  68 , respectively, of each of the first and second base plate attachment cantilevers  46 ,  48 . In other words, in an installed position, the distance between first and second aperture shelves  62 ,  64  and a reference plane in which the base plate  11  at least generally extends is less than the distance between the upper surfaces  66 ,  68  of the first and second base plate attachment cantilevers  46 ,  48  and this reference plane. As with the first and second base plate attachment cantilevers  46 ,  48 , the first and second aperture shelves  66 ,  68  are disposed in opposing relation. These aperture shelves  66 ,  68  are generally arcuately-shaped/concave and define at least a portion of the fastener aperture  50  of the ramp body  42  as well. In particular and referring to  FIG. 6 , a first reference line  70  connecting the first and second base plate attachment cantilevers  46 ,  48  is generally perpendicular to a second reference line  72  connecting the first and second aperture shelves  47 ,  49 . An intersection point  74  of these two reference lines  70 ,  72  generally corresponds with a central portion of the fastener aperture  50  of the load/unload ramp assembly  40 . It should be appreciated that the load/unload ramp assembly  40  may be in currently formed or of one-piece construction. In one embodiment, the load/unload ramp assembly  40  may be formed by injection molding techniques utilizing a suitable plastic, such as acetal or liquid crystal polymer (LCP). However, other manufacturing techniques and/or materials could be utilized in relation to the load/unload ramp assembly  40 . 
     Referring to  FIGS. 5-6 , the first surface  13  of the base plate  11  of the disk drive  10  includes a boss  82  which projects away from the first surface  13  and which includes a fastener receptacle  84  for the fastener  52 . Generally, this boss  82  is preferably integral with the base plate  11 . In other words, the base plate  11  and the boss  82  are preferably a one-piece unit, as is the entirety of the base plate  11  (e.g., formed by casting and/or machining such that there are no joints in the base plate  11 ). The fastener receptacle  84  of the boss  82  generally has threaded walls  94  designed to cooperatively engage the threaded shaft  54  of the fastener  52  upon insertion of the fastener  52  into the fastener receptacle  84  (see  FIG. 7 ). The base plate  11  also includes first and second mounting pads  86 ,  88  disposed in opposing relation on the first surface  13  of the base plate  11 , with the boss  82  being positioned between the first and second mounting pads  86 ,  88 . Thus, a reference line  73  connecting the first and second mounting pads  86 ,  88  generally extends through the boss  82  of the base plate  11 . The first and second mounting pads  86 ,  88  are recessed relative to the upper surface of the boss  82  of the base plate  11 . In other words, the upper surface of the boss  82  of the base plate  11  extends out and away from the first surface  13  of the base plate  11  a greater distance than the first and second mounting pads  86 ,  88  extend from the base plate  11 . These first and second mounting pads  86 ,  88  are generally designed to stabilize the load/unload ramp assembly  40  when installed on the base plate  11  and/or to minimize the couple created by the force of the fastener  52  which can contribute to bending/deformation of the ramp body  42  and, in turn, displacement of the ramp  44 . Thus, the first and second mounting pads are positioned on the first surface  13  of the base plate  11  so that they abut the boss  82  of the base plate  11 . Accordingly, the first and second mounting pads  86 ,  88  are disposed about the boss  82  of the base plate  11  so that the reference line  72  passing through the first and second mounting pads  86 ,  88  is perpendicular to the reference line  70  connecting the first and second base plate attachment cantilevers  46 ,  48  of the load/unload ramp assembly  40 ; thus, upon installation of the load/unload ramp assembly  40  onto the base plate  11 , the aperture shelves  62 ,  64  overlay at least portions of the first and second mounting pads  86 ,  88 . Accordingly, when the load/unload assembly  40  is installed on the first surface  13  of the base plate  11 , the bottom surface  43  of the load/unload ramp assembly found underneath the aperture shelves  62 ,  64  will be pressed against the mounting pads  86 ,  88  to prevent the ramp body  42  from bending to an undesired degree when installing the load/unload ramp assembly  40  onto the base plate  11 . 
     The base plate  11  also has first and second alignment holes  81 ,  83 , with the boss  82  of the base plate  11  being positioned between the first and second alignment holes  81 ,  83 . Thus, the base plate  11  has first and second alignment holes  81 ,  83  positioned on opposite sides of the boss  82  of the base plate  11  and first and second mounting pads  86 ,  88  positioned on opposite sides of the boss  82  of the base plate  11 , so that a reference line  71  connecting the first and second alignment holes  81 ,  83  is substantially perpendicular to another reference line  73  connecting the first and second mounting pads  86 ,  88 . Preferably, the intersection point  75  of these two lines  71 ,  73  generally corresponds with a central portion of the fastener receptacle  84  of the boss  82  of the base plate  11 . Other locations may be appropriate for the alignment holes  81 ,  83 . 
     Referring back to  FIG. 4 , the bottom surface  43  of the load/unload ramp assembly  40  has first and second alignment posts  90 ,  92  configured to fit into the respective first and second alignment holes  81 ,  83  of the base plate  11  illustrated in  FIG. 5 . Generally, the first and second alignment posts  90 ,  92  are complimentarily shaped to fit within the respective first and second alignment holes  81 ,  83  without allowing significant rotational movement (e.g., clocking) of the ramp body  42  upon installation of the load/unload ramp assembly  40  onto the base plate  11 . Put another way, upon installation of the load/unload ramp assembly  40  onto the base plate  11 , the first and second alignment posts  90 ,  92  of the load/unload assembly  40  are disposed within the respective first and second alignment holes  81 ,  83  of the base plate  11  to prevent any significant sliding and/or rotational movement of the load/unload ramp assembly  40  in relation to the base plate  11 . Accordingly, each of these alignment posts  90 ,  92  can have a variety of cross-sectional configurations which would enable each of these alignment posts  90 ,  92  to function in preventing rotational movement of the ramp body  42  including, but not limited to, circular, elliptical, triangular, and quadrilateral cross-sectional configurations. 
     Referring now to  FIG. 7 , the load/unload ramp assembly  40  has been installed on the base plate  11 . The shaft  54  of the fastener  52  extends through the fastener aperture  50  between the first and second free ends  47 ,  49 , and the head  56  of the fastener  52  exerts a force at least on the first and second free ends  47 ,  49 . As a result, the first and second base plate attachment cantilevers  46 ,  48  are generally deflected toward the base plate  11  to forcibly engage the load/unload ramp assembly  40  against the base plate  11 . In one embodiment, the first and second base plate attachment cantilevers  46 ,  48  are driven or deflected into forcible engagement with the base plate  11  at least at the respective first and second base plate engagement portions  58 ,  60  of the respective first and second attachment cantilevers  46 ,  48 . In the illustrated embodiment and upon full engagement of the fastener  52 , the respective upper surfaces  66 ,  68  of each of the first and second base plate attachment cantilevers  46 ,  48  is positioned in at least substantially horizontal relation when the load/unload ramp assembly  40  is installed on the base plate  11 , although such need not be the case. Prior to the installation of the load/unload ramp assembly  40  onto the base plate  11  and as noted above, the respective upper surfaces  66 ,  68  of each of the respective first and second base plate attachment cantilevers  46 ,  48  may be at least generally angled upward toward the top surface  41  of the ramp body  42 ; however, the respective first and second base plate attachment cantilevers  46 ,  48  are bent or deflected down toward to the bottom surface of the ramp body  42  upon tightening of the fastener  52  into the fastener receptacle  84  of the boss  82 . Other embodiments are contemplated wherein each of the upper surfaces  66 ,  68  of the respective first and second base plate attachment cantilevers  46 ,  48  remain substantially coplanar prior to installation, and upon installation, bend downward to exhibit an angle disposed toward the bottom surface  43  of the ramp body  42 . What is important is that the first and second base plate attachment cantilevers  46 ,  48  are deflected at least generally toward the base plate  11  by the fastener  52 , so as to forcibly engage the load/unload ramp assembly  40  with the base plate  11 . 
     In addition, the lower surfaces  78 ,  80  of each of the first and second base plate attachment cantilevers  46 ,  48  generally extend at least generally upwardly progressing toward the respective first/second free end  66 ,  68  of respective first/second base plate attachment cantilever  46 ,  48 . Even after the load/unload ramp assembly  40  has been installed on the base plate  11 , a space may exist between at least portions of the respective lower surfaces  78 ,  80  of the first and second base plate attachment cantilevers  46 ,  48  and the first surface  13  of the base plate  11 . However, in the embodiment illustrated in  FIG. 7 , at least the first and second base plate engagement portions  58 ,  60  of the respective first and second attachment cantilevers  46 ,  48  are forcibly engaged with the first surface  13  of the base plate  11  when the load/unload ramp assembly  40  is properly installed on the first surface  13  of the base plate  11 . In other embodiments, the first and second base plate attachment cantilevers (e.g.  46 ,  48 ) do not have engagement portions (e.g.  58 ,  60 ) which forcibly engage the first surface  13  of the base plate  11 . In such embodiments that lack engagement portions (e.g.  58 ,  60 ), the axial force of the head  56  of the fastener  52  on the upper surfaces  66 ,  68  of the respective first and second base plate attachment cantilevers  46 ,  48  deflects the first and second base plate attachment cantilevers  46 ,  48  with a sufficient force to fixedly engage the bottom surface  43  of the load/unload ramp assembly  40  against the respective mounting pads  86 ,  88  to secure the load/unload assembly  40  onto the base plate  11 . 
     The shaft  54  of the fastener  52  is threadingly engaged with the complimentarily threaded walls  94  of the fastener receptacle  84  of the boss  82  of the base plate  1 . Usually, the shaft  54  of the fastener  52  is generally moved further within the fastener receptacle  84  until the head  56  of the fastener  52  engages an upper surface  85  of the boss  82 . Stated another way, in an installed position, the head  56  of the fastener  52  generally has a lower surface  57  which is seated on the upper surface  85  of the boss  82  of the base plate  11 . In other words, once installed, the lower surface  57  of the fastener head  56  is in direct communication/engagement with the upper surface  85  of the boss  82  of the base plate  11 , while at the same time engaging the first and second base plate attachment cantilevers  46 ,  48 . 
     This fastener (preferably via the lower surface  57  of the head  56 )  52  generally exerts an axial force within a range of about 25 pounds up to about 400 pounds, and more preferably about 100 pounds up to about 200 pounds, on the upper surface  85  of the boss  82  of the base plate  11 . In addition to affecting a force on at least the upper surface  85  of the boss  82 , the lower surface  57  of the fastener head  56  generally deflects the first and second base plate attachment cantilevers  46 ,  48  which urges at least portions of the bottom surface  43  of the load/unload ramp assembly  40  into forcible engagement with underlying portions of the first surface  13  of the base plate  11 . This deflection of the first and second base plate attachment cantilevers  46 ,  48  which urges at least portions of the bottom surface  43  of the load/unload ramp assembly  40  into forcible engagement with underlying portions of the base plate  11  is generally in response to the shaft  54  of the fastener  52  being moved further within the fastener receptacle  84 . Accordingly, in an installed position, the first and second base plate attachment cantilevers  46 ,  48  each generally deflect from about 4 mils to about 8 mils in one embodiment due to the force exerted by the head  56  of the fastener  52  on the first and second base plate attachment cantilevers  46 ,  48 . Generally, this axial force exerted on the first and second base plate attachment cantilevers  46 ,  48  of the load/unload ramp assembly  40  is within a range of about 1 pound up to about 10 pounds. Thus, the axial force which is exerted on the boss  82  of the base plate  11  by the fastener  52  in the fully installed position is generally greater, and preferably significantly greater, than the axial force which is exerted on each of the first and second base plate attachment cantilevers  46 ,  48  by the fastener  52  in the fully installed position. This significantly reduces the potential for the fastener  52  retracting out of the fastener receptacle  84  over the life of the disk drive  10 . Moreover, this significantly reduces the load that is applied to the load/unload ramp assembly  40  to retain the same on the base plate  11 , so as to reduce the effects of creep that may occur over the life of the disk drive  10 . 
     Those skilled in the art will now see that certain modifications can be made to the apparatus and methods herein disclosed with respect to the illustrated embodiments, without departing from the spirit of the present invention. And while the invention has been described above with respect to the preferred embodiments, it will be understood that the invention is adapted to numerous rearrangements, modifications, and alterations, and all such arrangements, modifications, and alterations are intended to be within the scope of the appended claims.