Abstract:
The disengagement of a disk drive suspension limiter from the load beam is blocked by the provision of a tab that interfits with the load beam against separation during intended engagement.

Description:
REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 09/384,791, filed Aug. 26, 1999 U.S. Pat. No. 6,195,237. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention has to do with disk drive suspensions, and more particularly with limiters useful to limit undue travel of the suspension in the disk drive. Specifically, the invention is concerned with improvements in limiters to better retain engagement of the limiter with the suspension. 
     2. Related Art 
     Limiters are mechanical structures that limit the travel the tongue portion of the flexure makes relative to the load beam surrounding the flexure. Limitation of movement prevents damage to the flexure and thus to the suspension. Movement limitation is need both during lift-off of the suspension from the disk and during shock events such as sharp blows to the computer affecting the disk drive. Limiters are known to be positioned at the flexure tip and at the flexure tongue tip. The present invention is concerned with improvements in the flexure tongue tip type of limiter. In practice this type of limiter, which uses a specially shaped tongue tip to overlie the adjacent load beam portion, the limiter can slip past the opposing load beam surface and disengage if the contact is less than perfect as to angle and position inward on the load beam edge margin. The movement limitation intended is then lost. 
     SUMMARY OF THE INVENTION 
     It is an object, therefore, to provide an improved disk drive suspension. It is a further object to provide a disk drive suspension having an improved limiter feature. Yet another object is to provide a flexure tongue tip limiter of improved design against slipping and disengaging from the opposing load beam surface. It is a further object to provide a suspension limiter having cooperating tab and slot structure on opposing flexure tip and load beam surfaces to positively engage the surfaces against slippage and disengagement. 
     These and other objects of the invention, to become apparent hereinafter, are realized in a disk drive suspension comprising a load beam having a rigid portion and a flexure depending from the rigid portion, the flexure having a frame, a tongue cantilevered from the frame and generally spaced at a gap from the frame, and a tongue tip, the tip being movable relative to the frame, the flexure tip having a limiter comprising a continued flexure tip extent projecting out of the plane of the flexure tip and shaped to oppose the frame in frame contacting relation after a predetermined travel of the flexure, the limiter and the frame defining cooperating tab and slot structure arranged so that the limiter intersects with the surface of the frame in the contacted condition of the limiter with the frame against movement of the limiter into the gap. 
     In this and like embodiments, typically, the flexure tip continued extent defines a tab, the frame defining a slot shaped to receive the tab in intersecting relation, and the slot extends through the frame. 
     In a further embodiment, the flexure tongue tip continued extent extends normal to the flexure tongue and defines a U-shape open to the plane of the flexure, one leg of the U-shape being attached to the tongue tip, the other leg of the U-shape being parallel to the one leg and defining the tab, the other leg being sufficiently long to intersect with a slot formed in the frame upon the predetermined travel of the flexure, the slot extends through the frame, the frame portion has an edge margin adjacent the flexure tip, the slot comprising a rectangular slot in the frame edge margin, the rectangular slot has a given width, the tab being rectangular and of a lesser width than the slot, and the long axis of the tab is normal to the long axis of the slot. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further described ads to an illustrative embodiment in conjunction with the attached drawings in which: 
     FIG. 1 is an oblique view of the flexure; 
     FIG. 2 is a view like FIG. 1 showing the flexure positioned on a load beam; 
     FIG. 3 is a plan view of the flexure; and, 
     FIG. 4 is a view taken on line  4 — 4  of FIG.  3 . 
    
    
     DETAILED DESCRIPTION 
     The invention limiter offers better engagement than previous structures through the positive engagement of the tab in a slot, so that it cannot slip sideways off the opposing frame and into the gap. In addition the tab edge is, in preferred embodiments, squared off and not rounded. This increases strength at the tip and contributes to secure engagement without, however, blocking the desired up and down movement needed in the limiter. 
     With reference now to the drawings in detail, in FIGS. 1 and 2 the invention disk drive suspension at  10  comprises load beam  12  having a rigid portion  14  and a flexure  16  depending from the rigid portion. The flexure  16  has a frame  18 , a tongue  20  cantilevered from the frame and generally spaced at a gap  22  from the frame. Flexure tongue  20  has a tongue tip  24 . Tongue tip  24  is movable relative to the frame  18 . Flexure  16  has a limiter  26  comprising a continued flexure tip extent  28  projecting out of the major plane of the flexure tip and shaped as shown to oppose the frame  18  in frame contacting relation after a predetermined travel of the flexure. The flexure tip extent  28  and the frame  18  mutually define structure  32  comprising a cooperating tab  34  and slot  36 . The tab  34  and slot  36  are arranged as shown (FIGS. 1-4) so that the limiter tab  34  intersects with the surface  38  of the frame  18  in the contacted condition of the limiter  26  with the frame against movement of the limiter tab  34  into the gap  22  through nonengagement or disengagement of the tab with the frame surface  38 . Through the intersection of the tab  34  and the slot  36 , the squared off edge  42  of the tab enters the slot, shown to be a through slot, but the slot may be only partially through the frame  18 , and blocks lateral movement of the tab beyond the slot limits, and thus keeps the limiter structure  32  engaged. 
     As shown, the flexure tongue tip continued extent  28  extends normal to the major plane of the flexure  16  and tongue  20  and defines a U-shape open to the plane of the flexure. One leg  44  of the U-shape is attached to the tongue tip  24 ; the other leg  46  of the U-shape is parallel to the leg  44  and defines the tab  34 . Leg  46  is sufficiently long to intersect with the slot rectangular  36  formed in the edge margin  48  of the frame  16  upon the predetermined travel of the flexure. The rectangular slot  36  has a given width, the tab  34  is preferably rectangular and of a lesser width than the slot, and has its long axis normal to the long axis of the slot. 
     The invention thus provides a disk drive suspension having an improved limiter feature against slipping and disengaging from the opposing load beam surface comprising a cooperating tab and slot structure on opposing flexure tip and load beam surfaces to positively engage the surfaces against slippage and disengagement.