Abstract:
A disk drive suspension has a doubly increased dimple contact force through separate, differential deflections of the flexure frame toward the load beam so as to carry the flexure tongue having dimple engagement with the load beam closer to the beam, and thus have greater dimple contact force without adverse PSA alteration. Doubly deflecting the outrigger struts of the flexure toward the supporting load beam in differential relation with a greater deflection and local strut displacement in a first location and a lesser deflection and local strut displacement in a second location on the initially deflected portion of the frame outriggers provides increased dimple contact force.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/695,963, filed Jul. 1, 2005. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to disk drive suspensions, and, more particularly, to suspensions having doubly increased dimple contact force through separate, differential deflections of the flexure frame toward the load beam so as to carry the flexure tongue having dimple engagement with the load beam closer to the beam, and thus have greater dimple contact force. The invention further relates to suspension flexures, and to suspension manufacturing and operating methods. 
   More specifically, in a preferred embodiment, the invention provides increased dimple contact force from a generally conventional suspension and flexure arrangement by doubly deflecting the outrigger struts of the flexure toward the supporting load beam in differential relation to have a greater deflection and local strut displacement in a first location and a lesser deflection and local strut displacement in a second location on the initially deflected portion of the frame outriggers. 
   2. Description of the Related Art 
   Disk drive suspensions comprise in general an assembly of a mount plate, a load beam attached to an actuator and having and a beam portion that can include or comprise a stiffener, and a flexure that can be added to or formed with the beam portion. The flexure typically has a frame including outrigger struts and cantilevered tongue to carry a slider in gimballing relation about a dimple locus defined by a dimple on the tongue or the load beam and an opposing cooperating surface conversely on the load beam or tongue under a force referred to as the dimple contact force (sometimes DCF). The suspension assembly is in operative association with a disk. 
   BRIEF SUMMARY OF THE INVENTION 
   Maintaining an appropriate dimple contact force between the flexure tongue and the beam portion is critical to an effective disk drive suspension and its achievement must be compatible with other critical properties of the suspension. PSA, or pitch static attitude, is an important characteristic of a suspension. Dimple height (which is physically limited), dimple contact force, flexure moment of inertia and PSA are interrelated. In a given flexure geometry, assuming the moment of inertia is held constant, dimple height and dimple contact force are directly related. Increasing dimple contact force is then the same as raising the height of the dimple in terms of an increase or decrease in PSA. The invention use of a second deflection at the described angles in effect pre-biases the PSA in the correct direction and amount and the DCF can then be increased by raising the tongue toward the load beam without adversely affecting the intended PSA, or increasing dimple height. 
   It is an object of the invention, therefore, to provide novel and improved methods of manufacturing disk drive suspensions and the flexures thereof. It is a further object to provide an improved disk drive suspension in which dimple contact force is step-wise increased by successive deflections of the flexure frame. A further object is the provision of an improved flexure. A still further object is to provide methods and products in which staged deflections of the frame outrigger struts provide longitudinally spaced shoulders that carry the tongue supported by the frame into closer proximity to the load beam, and thus increase dimple contact force and improve performance of the suspension, e.g. increasing the dimple contact force by e.g. two times by modifying the suspension flexure according to the invention. 
   These and other objects of the invention to become apparent hereinafter are realized in a disk drive suspension flexure comprising a frame carrying a flexure tongue in cantilevered relation for dimple contact with a load beam, and a double deflection in the frame at longitudinally spaced locations to twice increase the dimple contact force between the tongue and the load beam. 
   In this and like embodiments, typically, the frame is differentially doubly deflected in relatively larger and relatively smaller deflections, the flexure tongue has a pitch angle that varies with variations in the extent of the smaller of the frame deflections, the flexure extends in a flexure plane and has a first frame portion, the first frame portion having a second frame portion, and the double deflection includes a first deflection at a first location in the frame first portion, the deflection being to a first angle to the flexure plane, and a second deflection at a second location in the second frame portion, the deflection being to a second, greater angle to the flexure plane, whereby the tongue is shifted toward the load beam in dimple contact force twice increasing relation, the second deflection is less than the first deflection, and/or the flexure tongue has a pitch angle at least partially determined by the second deflection. 
   In a further embodiment, the invention provides a disk drive suspension comprising a load beam and the foregoing flexure. 
   In a further embodiment, the invention provides a disk drive suspension comprising a load beam and a flexure assembly, the flexure comprising a base, a cross member, a pair of spaced, opposed outrigger struts extending from the base and supporting the cross member and a tongue cantilevered from the cross member and in dimple contact with the load beam, each outrigger strut having a first portion having at a first locus a first deflection arranged to increase the force of the dimple contact, each outrigger strut having at a second locus a second deflection arranged to further increase the dimple contact force. 
   In this and like embodiments, typically, each outrigger strut is twice deflected in the same direction at longitudinally spaced locations to define the first and second deflections, the tongue has a terminus, and there is also included each outrigger strut having the first locus in a transverse plane located between the base and the tongue terminus, each outrigger strut having the second locus in a transverse plane extending through the tongue; thus the first locus-including transverse plane can be a first transverse plane, the first locus transverse plane being a first transverse plane and each strut having the first locus in that first transverse plane, and the second locus in the second transverse plane extending through the tongue. 
   Further, in a typical embodiment, the flexure extends in a flexure plane, and each outrigger strut has a first portion first deflected to lie in a first portion plane at a first angle to the flexure plane, and a second portion separately deflected to lie in a second portion plane at a second, greater angle to the flexure plane. In this embodiment, typically, the second portion plane lies at an angle to the first portion plane that is less than the angle of the first portion plane to the flexure plane, and the first portion plane lies at an angle to the flexure plane that is at least three times greater than the angle of the first portion plane to the flexure plane. 
   In a further embodiment, the invention provides a disk drive suspension comprising an assembly of a load beam extended in a load beam plane and a flexure extended in a flexure plane, the flexure comprising a frame having a base fixed to the load beam, a transverse cross member longitudinally spaced from the base, a pair of laterally spaced and opposed longitudinally extended outrigger struts extending from the base and supporting the cross member and a tongue cantilevered from the cross member toward the base, the tongue having a free terminus the tongue and load beam having dimple contact in a dimple locus defined by the tongue and load beam, the frame having a first transverse plane normal to the flexure plane and between the tongue terminus and the base, the frame having a second transverse plane normal to the flexure plane and longitudinally spaced from the first transverse plane, the second transverse plane intersecting the tongue, each outrigger strut having a first portion having at a first locus within the first transverse plane a first relatively larger angle shoulder defined by a first strut deflection toward the load beam and arranged to increase the force of the dimple contact, each outrigger strut having a second portion continuation of the first portion, the second portion having at a second locus within the second transverse plane a second relatively smaller angle shoulder defined by a second strut deflection of the already deflected strut first portion toward the load beam and arranged to further increase the force of the dimple contact. 
   In this and like embodiments, the first shoulder disposes the strut first portion at an angle of about 1 to 30 degrees to the flexure plane, preferably about 2 to 10 degrees, e.g. 9 degrees, and/or the second shoulder deflection disposes the strut second portion at an angle between 1 and 30 degrees, and preferably 2 to 15 degrees to the strut first portion, e.g. 2 degrees, or about 1 to about 30 degrees to the flexure plane. 
   An invention method embodiment includes the method of manufacturing a disk drive suspension comprising an assembly of a load beam and a flexure, the flexure comprising a base, a cross member, a pair of spaced, opposed outrigger struts extending from the base and supporting the cross member and a tongue cantilevered from the cross member and in dimple contact with the load beam, the method including deflecting a first portion of each outrigger strut at a first locus to increase the force of dimple contact, and deflecting a second portion of each outrigger strut comprising the deflected first portion at a second locus to further increase the dimple contact force. 
   In this and like embodiments, typically, the method further includes locating the first locus relatively farther from the cross member than the second locus, the tongue having a terminus, and including also locating the first locus in a transverse plane located between the base and the tongue terminus, locating the second locus in a transverse plane extending through the tongue, having the transverse plane be a first transverse plane, and including also locating the second locus in a second transverse plane extending through the tongue and parallel with the first transverse plane, extending the flexure in a flexure plane, deflecting each outrigger strut first portion to lie in a first portion plane at a first angle to the flexure plane, and deflecting the outrigger strut second portion to lie in a second portion plane at a second, greater angle to the flexure plane, maintaining the second portion plane at an angle to the first portion plane that is less than the angle of the first portion plane to the flexure plane, and maintaining the first portion plane at an angle to the flexure plane that is at least three times greater than the angle of the second plane to the first portion plane. 
   A further method embodiment includes the method of manufacturing a disk drive suspension flexure, including carrying a flexure tongue in cantilevered relation on a frame for dimple contact with a load beam, and doubly deflecting the frame at longitudinally spaced locations to twice increase the dimple contact force between the tongue and the load beam. 
   In this and like embodiments, typically, the method includes also deflecting the frame differentially in longitudinally successive deflections so that successive deflections are smaller, varying the flexure tongue pitch angle by varying the second of the double deflections, having the flexure extend in a plane, and including also deflecting at a first location a first portion of the frame to a first angle to the flexure plane, and deflecting at a second location a portion of the frame first portion to a second, greater angle to the flexure plane to twice shift the tongue toward the load beam to twice increase the dimple contact force, deflecting the frame differentially in successive deflections so that successive deflections are smaller, and varying the flexure tongue pitch angle by varying the second of the double deflections. 
   A further method according to the invention includes a method of operating a disk drive suspension flexure, including carrying a flexure tongue in cantilevered relation on a frame in dimple contact with a load beam, and maintaining a double deflection in the frame at longitudinally spaced locations in dimple contact force between the tongue and the load beam twice increasing relation. 
   In this and like embodiments, typically, the method includes maintaining a differential in deflection between the double deflections such that deflection relatively closer to the locus of dimple contact is smaller than deflection relatively farther from the locus. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The invention will be further described in conjunction with the attached drawings in which: 
       FIG. 1  is an exploded oblique view of the suspension according to the invention; 
       FIG. 2  is an oblique view of the suspension flexure; 
       FIG. 3  is a plan view thereof; 
       FIG. 4  is a schematic depiction view of the flexure deflections and associated tongue displacement created thereby; and, 
       FIG. 5  is a side view, generally in elevation, of the deflected flexure 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With reference now to the drawings in detail, in  FIGS. 1-5  the invention disk drive suspension assembly  10  comprises a flexure  12  comprising a frame  14  carrying a flexure tongue  16  in cantilevered relation as shown for dimple contact in dimple locus  18  with a load beam  22  supported by mount plate  23  by attachment to flexure hinge portion  25 . Frame  14  has a double deflection  24 ,  26  in the frame at longitudinally spaced locations  28 ,  32  to twice, stepwise and progressively, increase the dimple  38  contact force between the tongue  16  and the load beam  22 . 
   Frame  14  is differentially doubly deflected at  24 ,  26  in relatively larger and relatively smaller deflections as shown. Flexure tongue  16  has a pitch angle α ( FIG. 5 ) to the flexure plane FP that varies with variations in the angle of the larger and smaller deflections  24 ,  26 . Flexure  12  extends in the flexure plane FP and has a first frame portion  34 . First frame portion  34  itself has a second frame portion  36 . Double deflections  24 ,  26  include a first deflection  24  at a first location  28  in the first frame portion  34 . The first deflection  24  is to a first angle α 24  to the flexure plane FP. The second deflection  26  is at a second location  32  in the second frame portion  36 . Second deflection  26  is to a second, greater angle α 26  to the flexure plane FP. First and second deflections  24 ,  26  shift or displace the tongue  16  toward the load beam  22  in dimple contact force increasing relation, e.g. twice increasing the DCF at dimple locus  18  comprising dimple  38  formed in the load beam  22  and opposing surface  42  of the tongue  16 . 
   More particularly, the invention disk drive suspension assembly  10  comprises load beam  22  and the flexure  12  supported by the mount plate  23 . Flexure  12  frame  14  defined by a base  44 , a cross member  46 , a pair of spaced, opposed outrigger struts  48 ,  52  extending from the base and supporting the cross member and tongue  16  cantilevered from the cross member and in dimple  38  contact with the load beam  22 . Each outrigger strut  48 ,  52  has a first portion  34  having at a first locus L 1  ( FIG. 2 ) a first deflection  24  arranged to increase the force of the dimple contact, and at a second locus L 2  a second deflection  26  arranged to further increase the dimple contact force in the dimple locus  18 . 
   As shown, each outrigger strut  48 ,  52  is twice deflected in the same direction (both toward the load beam  22 ) at longitudinally spaced locations  28  (within locus L 1 ) and  32  (within locus L 2 ) to define the first and second deflections  24 ,  26 . Locus L 1  is in a transverse plane TP 1  located between the base  44  and the tongue terminus  54 . Second locus L 2  is located in a second transverse plane TP 2  located to extend through the tongue  16 . Thus, first locus L 1 —including transverse plane TP 1 —is a first transverse plane and each strut  48 ,  52  has its first locus L 1  in that first transverse plane, and its second locus L 2  in second transverse plane TP 2  that extends through the tongue. 
   As in previous embodiments, flexure  12  extends in a flexure plane FP. Each outrigger strut  48 ,  52  has a first portion  34  first deflected to lie in a first portion plane  34 P at a first angle α 24  (between about 1 and about 30 degrees) to the flexure plane FP, and a second portion  36  separately deflected to lie in a second portion plane  36 P at a second, greater angle α 26  (α 26  is thus greater than α 24  and up to about 30 degrees) to the flexure plane. The second portion plane  36 P also lies at an angle α 36  to the first portion plane  34 P that is less than the angle α 24  of the first portion plane  34 P to the flexure plane FP. Generally, first portion plane  34 P lies at an angle α 24  to the flexure plane FP that is at least three times greater than the angle α 36  of the second portion plane  36 P to the first portion plane  34 P, where α 36  is between about 1 and about 30 degrees and typically about 2-10 degrees. 
   In a preferred embodiment, the invention disk drive suspension assembly  10  comprises load beam  22  extended in a load beam plane LBP and flexure  12  extended in flexure plane FP. Flexure  12  comprises frame  14  having a base  44  fixed to the load beam  22 , a transverse cross member  46  longitudinally spaced from the base, a pair of laterally spaced and opposed longitudinally extended outrigger struts  48 ,  52  extending from the base and supporting the cross member and tongue  16  cantilevered from the cross member toward the base, the tongue having a free terminus  54 . The tongue  16  and load beam  22  have dimple contact in a dimple locus  18  defined by the tongue and load beam; frame  14  has a first transverse plane TP 1  disposed normal to the flexure plane FP and located between the tongue terminus  54  and the base  44 . Frame  14  has a second transverse plane TP 2  disposed normal to the flexure plane FP and longitudinally spaced from the first transverse plane TP 1 . Second transverse plane TP 2  intersects the tongue  16 . Each outrigger strut  48 ,  52  has a first portion  34  having at a first locus L 1  within the first transverse plane TP 1  a first relatively larger angle shoulder  56  defined by a first strut deflection  24  toward the load beam  22  and arranged to increase the force of the dimple contact. Each outrigger strut  48 ,  52  has a second portion  36  continuation of the first portion  34 , the second portion having at a second locus L 2  within the second transverse plane TP 2  a second relatively smaller angle shoulder  58  defined by a second strut deflection  26  of the already deflected strut first portion  34  toward the load beam  22  and arranged to further increase the force of the dimple contact. 
   Typically, first shoulder  56  disposes the strut first portion  34  at an angle of about 1 to about 30 degrees to the flexure plane FP, and/or the second shoulder  58  deflection disposes the strut second portion  36  at an angle between 1 and 30 degrees to the plane FP and has an angle α 36  about 2 to about 10 degrees to the strut first portion  34 . 
   In its method aspects, the invention methods include manufacturing a disk drive suspension assembly  10  comprising a load beam  22  and a flexure  12  supporting the load beam on mount plate  23 , the flexure comprising a base  44 , a cross member  46 , a pair of spaced, opposed outrigger struts  48 ,  52  extending from the base and supporting the cross member and a tongue  16  cantilevered from the cross member and in dimple contact with the load beam. The manufacturing method includes deflecting a first portion  34  of each outrigger strut  48 ,  52  at a first locus L 1  to increase the force of the dimple contact, and deflecting a second portion  36  of each outrigger strut  48 ,  52  comprising the deflected first portion  34  at a second locus L 2  to further increase said dimple contact force. 
   The noted manufacturing method further includes locating the first locus L 1  relatively farther from the cross member  46  than the second locus L 2 , tongue  16  having a terminus  54 , locating the first locus L 1  in a transverse plane TP 1  located between the base  44  and the tongue terminus, locating the second locus in a transverse plane TP 2  extending through the tongue, having transverse plane TP 1  be a first transverse plane, and including also locating the second locus L 2  in second transverse plane TP 2  extending through the tongue and parallel with the first transverse plane TP 1 , extending the flexure  12  in a flexure plane FP, deflecting each outrigger strut  48 ,  52  first portion  34  to lie in a first portion plane  34 P at a first angle to the flexure plane FP, and deflecting the outrigger strut second portion  36  to lie in a second portion plane  36 P at a second, greater angle α 26  to the flexure plane FP, maintaining the second portion plane  36 P at an angle α 36  to the first portion plane  34 P that is less than the angle α 24  of the first portion plane  34 P to the flexure plane FP, and maintaining the first portion plane  34 P at an angle α 24  to the flexure plane that is at least three times greater than the angle α 36  of the second plane  36 P to the first portion plane  34 P. 
   A further invention manufacturing method embodiment includes manufacturing a disk drive suspension flexure  12 , including carrying a flexure tongue  16  in cantilevered relation on a frame  14  for dimple contact with a load beam  22 , and doubly deflecting the frame at longitudinally spaced locations  24 ,  26  to twice increase the dimple contact force between the tongue and the load beam. This method typically also includes deflecting the frame  14  differentially (i.e. not identically) in physically if not temporally successive deflections (i.e. deflections at  24  and  26  can be simultaneous or separate in time, but are always physically spaced) so that successive deflections are smaller, varying the flexure tongue pitch angle α of tongue plane  16 P to flexure plane FP by varying the second deflection, i.e. deflection  26  of the double deflections  24 ,  26 , having the flexure  12  extend in a plane FP, deflecting at a first location  28  a first portion  34  of the frame  14  to a first angle α 24  to the flexure plane FP, and deflecting at a second location  32  a portion  36  of the frame first portion  34  to a second, greater angle α 26  to the flexure plane FP to twice shift the tongue  16  toward the load beam  22  to twice increase the dimple contact force, deflecting the frame  12  differentially in successive deflections  24 ,  26  so that successive deflections are smaller, and varying the flexure tongue pitch angle α by varying the second deflection (deflection  26 ) of the double deflections  24 ,  26 . 
   The invention further contemplates a method of operating a disk drive suspension flexure  12 , including carrying a flexure tongue  16  in cantilevered relation on a frame  14  in dimple  38  contact with a load beam  22 , and maintaining a double deflection  24 ,  26  in the frame at longitudinally spaced locations  28 ,  32  in dimple contact force twice increasing relation between the tongue and the load beam. Typically, the just described method includes maintaining a differential in deflection between the double deflections  24 ,  26  such that deflection  26  relatively closer to the locus  18  of dimple  38  contact is smaller than the deflection  24  relatively farther from the locus. With the foregoing methods, a new suspension product has doubled dimple contact force over a previous product version having a single deflection in the frame, from a DCF (dimple contact force) rating of 0.12 gf to one of 0.25 gf. 
   Table 1 shows the modeled DCF of the previous (Prior Art) product design. “Bend Location” refers to strut deflection. 
   
     
       
             
           
             
             
             
             
             
             
           
         
             
               TABLE 1 
             
           
           
             
                 
             
             
               Modeled DCF Results 
             
           
        
         
             
                 
               Bend 
                 
                 
               Model 
                 
             
             
                 
               Location 
               Angle 
               Offset 
               DCF 
               Measured* 
             
             
               Description 
               (in) 
               (deg) 
               Height 
               (g) 
               DCF 
             
             
                 
             
             
               Prior Art 
               — 
               — 
               — 
               0.14 
               0.12 
             
             
                 
             
             
               *Average of 15 samples. 
             
           
        
       
     
   
   Table 2 shows the 1 st  and 2 nd  bend or deflection angle and location on the outrigger struts to achieve a pitch angle of from 0.98 to 2.49 degrees while increasing the DCF 0.20 g over the Prior Art suspension in Table 1. 
   
     
       
             
           
             
             
             
             
             
             
             
           
         
             
               TABLE 2 
             
           
           
             
                 
             
             
               Flexure Formed Geometry/Modeled DCF 
             
           
        
         
             
                 
                 
               1st Bend 
                 
                 
               Resulting 
                 
             
             
                 
               1st Bend 
               Angle 
                 
               2nd 
               Pitch 
             
             
                 
               Location 
               (BA) 
               2nd 
               BA 
               Angle 
               Modeled 
             
             
               Profile 
               (BL) 
               (α24) 
               BL 
               (α36) 
               (α16) 
               DCF 
             
             
                 
             
             
               p3 
               0.19 
               9 
               0.235 
               0.00 
               0.98 
               0.34 
             
             
               p7 
               0.19 
               9 
               0.235 
               0.50 
               1.47 
               0.34 
             
             
               p8 
               0.19 
               9 
               0.235 
               0.75 
               1.72 
               0.34 
             
             
               p4 
               0.19 
               9 
               0.235 
               1.00 
               2.00 
               0.34 
             
             
               p9 
               0.19 
               9 
               0.235 
               1.50 
               2.49 
               0.34 
             
             
                 
             
             
               *Bend location is measured from locus L3; Bend and Pitch angles are in degrees. 
             
           
        
       
     
   
   The invention, thus provides novel and improved methods of manufacturing disk drive suspensions and the flexures thereof, and an improved disk drive suspension and flexure in which dimple contact force is step-wise increased by successive deflections of the flexure frame in which the staged deflections of the frame outrigger struts provide longitudinally spaced shoulders that carry the tongue supported by the frame into closer proximity to the load beam and thus increase dimple contact force and improve performance of the suspension, e.g. increasing the dimple contact force by two times by modifying the suspension flexure. The foregoing objects are thus met.