Patent Document

TECHNICAL FIELD  
         [0001]    This invention relates to the attachment of slide rails, such as for extendable rack-mounted electronic components, and such.  
         BACKGROUND  
         [0002]    Computer systems are frequently comprised of several discrete components, each packaged in a serviceable box or chassis of a common width and one of various standard heights. Several such components of a system may be mounted in a rack designed to enable the components to be individually removed for service or replacement. Flanges of the components may be bolted, for example, in any number of positions along a vertical series of holes along the rack.  
           [0003]    To improve serviceability, some computer server components have been mounted into racks on extendable slide rails, such as are employed on desk and cabinet drawers. One elongated portion of a rail is firmly attached to the server component chassis, such as by screws, and a mating portion of the rail is rigidly secured to the rack. The two mating portions of the rail can slide in relation to each other on bearing surfaces, between stops, to enable the component to be readily pulled partially from the rack for maintenance or service. The two mating portions of some slide rails can be disconnected from each other to completely remove the server component, with its portions of two corresponding slide rails still attached, from the rack. 
       
    
    
     DESCRIPTION OF DRAWINGS  
       [0004]    [0004]FIG. 1 is a perspective view of a component rack.  
         [0005]    [0005]FIG. 2 shows the mounting of a component chassis to a rack with two slide rails.  
         [0006]    [0006]FIG. 3 is an exploded, perspective view of a three-section, quick-release slide rail.  
         [0007]    [0007]FIGS. 4 and 5 illustrate the mounting of the inner slide rail member to a component chassis.  
         [0008]    [0008]FIGS. 5A and 5B are enlarged views of areas  5 A and  5 B, respectively, of FIG. 5.  
         [0009]    [0009]FIG. 6A shows detail of the keyhole slot seen in FIG. 5A.  
         [0010]    [0010]FIG. 6B is a cross-sectional view through a standoff projection, taken along line  6 B- 6 B in FIG. 4.  
         [0011]    [0011]FIG. 7 is a perspective view of a spring clip.  
         [0012]    [0012]FIGS. 8 and 9 are face and side views, respectively, of the spring clip of FIG. 7.  
     
    
     DETAILED DESCRIPTION  
       [0013]    In FIG. 1, a rack  10  as known in the art has four upright, metal beams  12  provided with corresponding series of mounting holes for mounting brackets and rails supporting computer and other electronic equipment at various elevations in the rack. The beam and hole spacing of such racks has become somewhat standard in the industry.  
         [0014]    As shown in FIG. 2, a single computer component  14  is mounted to the upright beams  12  of the rack with a pair of extendable slides  16 . Each slide  16  consists of three elongated members forming a telescoping assembly. An outer member  18  is mounted rigidly between two upright beams  12  on each side of the rack, such as by threaded fasteners. An intermediate member  20  travels within a track defined by outer member  18 , on a series of roller bearings. When fully extended, the travel of intermediate member  20  is limited by a mechanical stop (not visible in this view). When retracted, the intermediate member is contained within the length of the outer member  18 . An inner member  22  (shown detached from the rest of the slide rail) is rigidly secured to the chassis  24  of component  14 , by means described more fully below. To install component  14  into the rack, its attached inner slide members  22  are slid into the intermediate members  20  that are already secured in the outer members  18  attached to the rack. For local service, component  14  can be pulled from the rack by extending the slides  16 . If more extensive service or replacement is required, however, inner members  22  can be slid out of their respective intermediate slide members  20  to completely remove the component from the rack, without disassembling the inner slide members  22  from the component chassis  24  or detaching the outer slide members  18  from the rack.  
         [0015]    Outer slide member  18  may be rigidly secured to the rack by any appropriate attachment means, such as threaded fasteners, rivets or quick-release pins. The outer slide member may be permanently secured to the rack, if desired, although it is preferably removable for replacement or repositioning.  
         [0016]    More detail of the slide assembly  16  is visible in FIG. 3. Outer slide member  18  includes two spaced-apart brackets  26  with holed flanges for mounting the slide in a rack. An rear stop  28  limits the travel of intermediate member  20  in one direction, while a releasable catch  28  of the intermediate member engages a tab (not shown) along the web of outer member  18  when the intermediate member is fully extended, to limit travel in the other direction. Catch  28  is pivotably attached to intermediate member  20 , and latches intermediate member  20  to outer member  18  at full extension. When inner member  22  has been fully retracted, it engages and rotates catch  28  to enable subsequent retraction of intermediate member  20 , ensuring sequential retraction. Multiple bearing balls  30  are held within ball retainer  32  to provide for rolling contact between intermediate member  20  and inner member  22 . A similar retainer and series of balls (not shown) form the rolling interface between intermediate member  20  and outer member  18 .  
         [0017]    A spring clip  34  extends from the outboard side of the web of inner member  22  to engage the edge of a hole  36  through the web of intermediate member  20  when the inner member is fully extended. Once fully extended, the engagement of clip  34  with hole  36  also prohibits retraction of the inner member within the intermediate member without manually compressing clip  34  for disengagement. A distal, free end  38  of clip  34  is exposed beyond the web of intermediate member  20  with the inner member fully extended, for manipulation. Manually compressing and disengaging clip  34  also releases inner member  22  for complete removal from the intermediate member.  
         [0018]    Inner member  22  is also provided with three keyhole slots  40  through its central web, and a single aperture  42 , for quick mounting of the inner member to a component housing without the use of tools, as illustrated in FIGS. 4 and 5. Housing  24  has a corresponding series of three standoff projections  44  that are received in enlarged ends of keyhole slots  40 , and a spring clip  46  (described in more detail below) exposed through an aperture  48  through the housing wall to engage an edge of aperture  42  of the inner slide member  22 .  
         [0019]    After the inner slide rail member  22  is moved toward the side of the component housing  24  in a normal direction until the heads of projections  44  have passed through the larger ends of keyhole slots  40  (FIG. 4), the inner slide rail member  22  is slid forward along component housing  24  in the direction of arrow “A” (FIG. 5) until spring clip  46  snaps into aperture  42  of the inner rail member (see also FIG. 5B) to secure the inner rail member against being slid in the opposite direction, with the heads of projections  44  overlapping the web of the inner rail member in the vicinity of keyhole slots  40  (see also FIG. 5A) to retain the inner member against the side of the component housing.  
         [0020]    [0020]FIG. 6A shows the profile of the keyhole slots  40  of the inner slide member. The larger end has a radius R 1  of about 0.155 inch (3.94 millimeters), while the smaller end has a radius R 2  of about 0.1 inch (2.5 millimeters). The centers of the arcs defining the two ends are separated by a distance “D” of about 0.3 inch (7.6 millimeters).  
         [0021]    The structure of one of the corresponding steel standoff projections  44  is shown in FIG. 6B. The circular standoff has a head  50  with an overall diameter of about 0.275 inch (7.0 millimeters) and a thickness of about 0.1 inch (2.5 millimeters). This head is integrally formed with a stem  52  having a diameter of about 0.195 inch (5.0 millimeters) that is knurled and pressed into a hole in the component housing wall until the inner end of the stem is flush with the inner surface  54  of the housing  24 , which is formed of steel having a nominal wall thickness of about 0.48 inch (12 millimeters). Once assembled to the component housing, the inner surface of head  50  of projection  44  is disposed about 0.05 inch (1.3 millimeters) from the outer surface of the housing, for receiving the nominal thickness of the web of the inner slide member beneath the projection head. Because head  52  has a thickness of only about 0.1 inch (2.5 millimeters), in the final assembly it extends only about 0.1 inch (2.5 millimeters) beyond the outer surface of the inner slide member and does not interfere with the retraction of the inner slide member within the intermediate slide member. The dimensional tolerances, and nominal clearance between projection  44  and the inner slide member keyhole slot, should be chosen to minimize free play in the final assembly, while still enabling assembly by hand.  
         [0022]    Referring now to FIGS.  7 - 9 , elongated spring clip  46  is formed of ¼-hard spring steel having a nominal thickness “t” of about 0.025 inch (0.64 millimeter). Two holes  56  through the clip are for permanently securing the clip to the inner surface of the component housing, either by threaded fasteners, rivets, staking or other attachment means. Spaced longitudinally from holes  56  is a raised wedge  58  having length “L” of about 0.56 inch (14 millimeters) and height “H” of about 0.15 inch (3.8 millimeters), formed of the same sheet stock by a punch-forming operation. Wedge  58  has a distal edge  60  for engaging the edge of the aperture in the inner slide member web. The length of clip  46  between holes  56  and wedge  58  enables the clip to be flexed out of its plane to deflect into the component housing as the inner slide member web is pressed against wedge  58 . The resiliency of the material causes wedge  58  to spring back to its original position once aligned with inner member aperture  42  (see FIG. 5B).  
         [0023]    Other embodiments are within the scope of the following claims. For example, other hand-manipulable or automatic locking means may be employed instead of a spring clip, such as a plunger alignable with a hole, to lock the inner slide member to the component housing once slid into position. The keyhole slots and standoffs may be fashioned of many different profiles and structures, enabling different motion sequences and directions for attaching the inner rail member. The standoffs can be secured to the inner slide member, with corresponding keyhole slots in the component housing. Multiple spring clips may be employed to further reduce any risk of inadvertent release. These are but a few of the variations that are envisioned within the spirit and scope of the invention as claimed.

Technology Category: g