Abstract:
A snap-mount blanking panel for an equipment rack or cabinet enclosure has ergonomic grips spaced laterally inwardly and offset forwardly to permit comfortable and reliable mounting and removal of the blanking panel regardless of lateral clearance. A special stacking structure engages the grips in a manner to position a blanking panel, when stacked upon a lower blanking panel, in a fixed and stabilized relation to the lower blanking panel. The stacking features enable stable stacking of multiple units, one on top of another, without requiring external confinement of the stack.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/972,916 filed Jan. 11, 2008 (now U.S. Pat. No. 7,959,015, granted Jun. 14, 2011), the priority of which is hereby claimed and the content of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention pertains to the field of standardized racks and cabinet enclosures for electronic equipment and, in particular, to blanking panels for standardized equipment racks and cabinet enclosures. 
     BACKGROUND OF THE INVENTION 
     Electronic devices, such as computer servers and related computer equipment, and other electronic devices, are commonly mounted in standardized racks and cabinet enclosures having spaced-apart, (typically vertical) mounting rails with a series of holes defining a plurality of uniformly-spaced mounting locations for mounting the electronic devices in a closely-spaced, stacked manner. Standards for such racks and cabinet enclosures have been published by various trade organizations, including the Electronic Industries Alliance (EIA 310-D), the International Electrotechnical Commission (IEC 60297), and the Deutsches Institut fur Normung e.V. (DIN 41494 SC48D), which standards are hereby incorporated by reference. 
     Electronic devices suitable for mounting in such standardized racks and cabinet enclosures have heights substantially equal to an integer multiple of a predetermined height unit (U) of the standardized rack or cabinet enclosure (e.g., 1 U, 2 U, 3 U . . . nU). For example, a 1 U device may have a height of 44.45 mm (or 1.175 inches). 
     Blanking panels are often placed between electronic devices in standardized racks and cabinet enclosures to occupy unused mounting locations, primarily to control the flow of air in and around the rack or cabinet enclosure, and for organizational, safety and aesthetic reasons. As above, such blanking panels have heights substantially equal to an integer multiple of the predetermined height unit (U) of the standardized rack or cabinet enclosure (e.g., 1 U, 2 U, 3 U . . . nU). 
     Electronic devices and blanking panels (including the blanking panel of the present invention) which are mutually suitable for mounting in an electronic equipment rack or cabinet enclosure (constructed according to one of the above-mentioned standards, or another standard) may be described collectively herein as “conforming” or as “conforming devices.” 
     Early blanking panels consist of a generally flat sheet of material (e.g., sheet metal) having mounting holes on opposite ends which are suitable to mount the blanking panel to the rack or cabinet enclosure using mechanical fasteners, such as screws, bolts, or captive hardware, or the like. The fasteners are inserted into the holes in the mounting rails of the standardized rack or cabinet enclosure. Later model blanking panels are integrally-formed of injection molded plastic and have snap-mount structures on each end which engage opposing surfaces of the mounting rails to securely (and removably) attach the blanking panel to the rack or cabinet enclosure. 
     Such prior constructions of blanking panels generally serve their intended purposes; however, flat sheet blanking panels often warp or bend and lose sealing effectiveness in the rack, and the prior snap-mount blanking panels do not provide an effective barrier to air flow. Further, the prior snap-mount blanking panels can be difficult and uncomfortable to engage and disengage from the rack or cabinet enclosure because inadequate room is available from the finger lifts or turn buttons to clear the edges of the rack or cabinet. Indeed, it is not uncommon for users of prior blanking panels to abrade or scrape their hands and knuckles on the cabinet enclosure or rack when mounting or removing the panels. Also, the physical arrangement of devices and blanking panels in racks and cabinet enclosures can be quite dynamic, requiring frequent movement of devices and reconfiguration of the blanking panels. Thus, the difficulty and discomfort involved in installing and replacing prior blanking panels can be significant. 
     The prior blanking panels do not allow for stable stacking of multiple blanking panels for storage and thus must be stored in a container, such as a corrugated box, which is undesirable for data centers and the like. In addition, the prior blanking panels do not provide a means for reliably measuring atmospheric conditions of the ambient area which is often desirable in data centers and the like, or provide an area for mounting signage or for a writing surface which can provide information about the rack or devices therein. Further, prior blanking panels do not provide a means to pass cable through the blanking panel. 
     Therefore, what is desired is an improved blanking panel for standardized electronic equipment racks and cabinet enclosures which is convenient and comfortable to engage and disengage from the rack, which provides a substantial and reliable seal against air flow in the areas immediately above and below the blanking panel, which provides for reliable, stable stacking of multiple blanking panels outside a container, which provides a reliable means for measuring atmospheric conditions in the ambient area, which provides an area for mounting signage or for a writing surface, and which provides a cable pass-through. 
     SUMMARY OF THE INVENTION 
     The invention comprises a snap-mount blanking panel for an equipment rack or cabinet enclosure of the type having spaced-apart mounting rails for mounting electronic devices and equipment. The blanking panel has a front wall, first and second end portions on opposite lateral sides of the front wall, and means for releasably connecting the blanking panel to the mounting rails in a resilient, snap-mount manner, with the front wall facing outward. The releasable connecting means is disposed on the first and second end portions of said blanking panel. 
     Both the first and second ergonomic grips may be used for two-handed connection and removal of the blanking panel. The first and second grips are accessible from the front of the blanking panel and are preferably engagable between a finger and thumb, but can also be engaged with one finger in some embodiments. 
     Each grip preferably has a finger bearing surface and a thumb bearing surface sized to engage a majority of a palmar aspect of the finger and thumb of the user, respectively, from about the DIP (distal interphalangeal) joint of the finger/thumb to about the end of the finger/thumb, respectively. The DIP joint of each finger and thumb interconnects the outermost (i.e., distal) finger/thumb bone (phalanx) to the middle finger/thumb bone and is generally located at the DIP crease—in the palmar aspect (i.e., fingerprint area) of the finger/thumb—between the distal and middle phalanges. 
     Each grip is spaced laterally inward from an associated adjacent end portion of the blanking panel at least about 5 cm to permit engagement of the grip by the user, with said first and second hands of the user located entirely between said first and second ends of the blanking panel. The laterally inward placement of the grips allows the user to mount and remove the blanking panel without physical stress or abrasion to the hands of the installer during installation and removal of large quantities of blanking panels. 
     The user may conveniently, comfortably and reliably engage and remove the blanking panel from the equipment rack or cabinet enclosure by grasping the first and second grips regardless of the clearance laterally outward of the ends of the blanking panel and regardless of laterally inwardly projecting rack frame or door structure. This design and mechanism eliminates the problems of discomfort in installing and removing, and of abrading or scraping hands and knuckles. 
     The stacking structure of the blanking panel allows multiple blanking panels to be stacked in a stable manner without the use of an external support structure, such as a box or the like. 
     Resiliently flexible sealing skirt members extend along the edges of the blanking panels and form a positive seal with electronic equipment or other blanking panels in mounting locations immediately above and below the blanking panel to prevent air flow therebetween. The sealing blanking panels may be mounted and removed without the need to disassemble and re-assemble adjacent blanking panels or electronic equipment. 
     Further, the blanking panel provides an off-set platform for mounting instruments to measure the ambient atmospheric conditions, for mounting signage or for a writing surface. Further, the blanking panel may provide a cable pass-through. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a complete understanding of the above and other features of the invention, reference shall be made to the following detailed description of the preferred embodiments of the invention and to the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a blanking panel constructed according to the invention; 
         FIG. 2  is a front elevation view of the blanking panel of  FIG. 1 ; 
         FIG. 3  is a bottom plan view of the blanking panel of  FIG. 1 ; 
         FIG. 4A  is a perspective cross sectional view of the blanking panel, taken along line  4 A- 4 A of  FIG. 2 ; 
         FIG. 4B  is a cross sectional view of the blanking panel, taken along line  4 B- 4 B of  FIG. 2 ; 
         FIG. 5  is a rear perspective view, showing the nested stacking support features of the blanking panel of  FIG. 1 ; 
         FIG. 6  is cross sectional view, showing nested stacking of two blanking panels constructed according to the invention; 
         FIG. 7A  is a side elevation cross sectional view, showing two blanking panels mounted in a standardized electronic equipment rack; 
         FIGS. 7B &amp; 7C  are a top plan view and a perspective view, showing a blanking panel mounted in a standardized electronic equipment rack; 
         FIG. 8A  is a section view of the blanking panel of  FIG. 1 , showing the cross section of the skirt members; 
         FIG. 8B  is a section view of the blanking panel, showing a pliant over-mold. 
         FIG. 8C  is a section view of the blanking panel, showing pliant end portions of the sealing skirt members; 
         FIG. 9  is a perspective view of a blanking panel constructed according to the invention having an off-set platform mounted to a front wall of the blanking panel; 
         FIG. 10  is a perspective view of the off-set platform of  FIG. 9 ; 
         FIG. 11  is a front elevation view of a second embodiment of the blanking panel; 
         FIG. 12  is a perspective view of the blanking panel of  FIG. 11 ; 
         FIG. 13  is a partial cross sectional view, taken along line  13 - 13  of  FIG. 1 ; and 
         FIG. 14  is a perspective view of a third embodiment of the blanking panel (2 U). 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-9 , a 1 U version of a blanking panel  10  constructed according to the invention includes a pair of ergonomic grips  14 ,  16  formed in a front wall  12  to facilitate secure, comfortable mounting and removal of the blanking panel  10  from a standardized electronic equipment rack or cabinet enclosure. 
     The blanking panel  10  has a generally rectangular configuration and is advantageously formed of a unitary molding of structural plastic material, and preferably an ABS plastic material having fire retardant characteristics. 
     Preferably, the blanking panel  10  has a lateral length, as measured from one end  36  to an opposite end  38 , suitable for mounting in a standardized electronic equipment rack or cabinet enclosure, for example about 49 mm (i.e., about 19 inches). The above-mentioned ANSI/EIA-310-E standard specifies acceptable distances of 482.2 mm, 609.6 mm, or 782.2 mm, (i.e., about 19 inches, 24 inches, or 30 inches), with a tolerance of about +/−4 mm. Further, the blanking panel  10  has a height, as measured from a top edge of a front wall  12  to a bottom edge thereof, substantially equal to or slightly less than an integer multiple of a predetermined height unit (U) of the standardized equipment rack or cabinet enclosure (1 U, 2 U, 3 U . . . nU), for example about 44.45 mm, or about 1.75 inches. 
     The grips  14 ,  16  are disposed on the front wall  12  of the blanking panel  10 , and are operable for mounting and removal of said blanking panel  10  to and from the mounting rails. The grips  14 ,  16  are accessible from the front wall  12  of the blanking panel  10  when the blanking panel  10  is mounted to the mounting rails with devices (or other blanking panels) occupying mounting locations immediately above and below the blanking panel. 
     Each grip  14 ,  16  has a first bearing surface  94  ( FIGS. 4A &amp; 4B ) sized and shaped to engage a substantial portion of the palmar aspect of a digit of a hand of the user (e.g., a finger or thumb). The first bearing surface  94  is spaced at least about 5 cm (and preferably about 9 cm) from an adjacent end portion  36 ,  38  of the blanking panel  10 , and is operable to receive a pulling force exerted on the blanking panel  10  by the user, for removing the blanking panel from the mounting rails. The first bearing surface  94  faces (at least partially) toward the rear of the blanking panel. In other words, a normal vector of the first bearing surface  94  (or at least a component of a normal vector) points toward the rear of the blanking panel  10 , such that a pulling force exerted perpendicular on the first bearing surface by a user will tend to dislodge the blanking panel  10  from the mounting rails. The first bearing surface  94  may have a concave or complex shape, in which case normal vectors (or components thereof) of a substantial portion or majority of the surface face toward the rear of the blanking panel. 
     Each grip  14 ,  16  also includes a second bearing surface  95  proximate the first bearing surface  94 , which second bearing surface  95  is operable to receive a pushing force for installing the blanking panel  10 . The first and second bearing surfaces  94 ,  95  of each grip  14 ,  16  are preferably substantially parallel and are engagable between the finger and thumb of a hand of a user for mounting and removal of the blanking panel  10 . 
     Preferably, the first bearing surface  94  forms a finger bearing surface  28  and the second bearing surface  95  forms a thumb bearing surface  30 . It is intended that the user engage the finger bearing surface  28  with a finger and likewise, the thumb bearing surface  30  with a thumb. However, it can be appreciated that the reverse may also be possible, or the user may use two fingers from each hand, instead of a finger and thumb. Therefore, as used herein the term “finger bearing surface” shall include suitable for contact by a thumb, and the term “thumb bearing surface” shall include a surface suitable for contact by a finger. 
     Each grip  14 ,  16  has a contact member  24  which may be engaged between a finger and thumb of the user for mounting and removal of the blanking panel  10 . The first bearing surface  94  and/or finger bearing surface  28  is preferably disposed on an interior portion of the contact member  24 . The finger bearing surface  28  is sized to engage a majority of the palmar aspect of the fingertip of the user beyond from at least about the DIP joint of the finger to about the end extremity of the finger, or, alternatively, beyond from at least about a mid-point between the DIP joint to about the end extremity of the finger. Thus, the finger bearing surface  28  preferably has a length (as measured along the finger insertion axis  23 ) of about 1-4 cm and a width (measured along an axis or arc perpendicular to the finger insertion axis  23 ) of about 1-2 cm. As depicted, the finger bearing surface  28  is disposed on an interior surface  27  of the contact member  24 . The finger bearing surface  28  preferably has a concave shape to comfortably conform to the convex shape of an average adult fingertip. Alternatively, the finger bearing surface  28  may be substantially planar, or another suitable surface shape. 
     As set forth above, the DIP joint of each finger and thumb interconnects the outermost (i.e., distal) finger/thumb bone (phalanx) to the middle finger/thumb bone and is generally located at the DIP crease—in the palmar aspect (i.e., fingerprint area) of the finger/thumb—between the distal and middle phalanges. 
     The contact member  24  (and optionally an adjacent portion  31  of the front wall  12 ) forms the second bearing surface  95  and/or thumb bearing surface  30 , which is sized to engage a majority of a palmar aspect of the of the thumb of the user beyond from at least about the DIP joint of the thumb to about the end extremity of the thumb (or, alternatively, beyond from at least about a mid-point between the DIP joint and the end extremity of the thumb). Thus, the thumb bearing surface  30  preferably has a length of about 1-4 cm and a width of about 1-2 cm. As depicted, the thumb bearing surface  30  is disposed on an exterior surface  29  of the contact member  24 . The thumb bearing surface  30  may have a convex shape, a substantially planar shape, or another suitable shape. 
     Each grip  14 ,  16  also includes a back wall  22 , an end wall  20 , and an opening  26 . The opening  26  is partially defined by a free edge  21  of the contact member  24 . The back wall  22  projects rearward from the front wall  12  and laterally inward (i.e., away from the adjacent end  36 ,  38 ), and forms a rearward and laterally inwardly projecting, concave recess  18  sized and shaped to, at least partially, receive a finger therein. The contact member  24  extends over the concave recess  18  formed by the back wall  22  and projects, from the front wall  12  to the free edge  21 , forwardly and laterally outward, generally toward the adjacent end  36 ,  38  and parallel to the back wall  22 , such that the back wall  22 , contact member  24  and end wall  20  form a partially enclosed finger cavity  19  for receipt of a finger therein. 
     Each finger cavity  19  has a depth sufficient to receive an average adult finger of user up to at least about an outermost joint of the finger (which is the distal interphalangeal—DIP—joint), for example up to about 2-4 cm, without any, or any substantial amount of, compression or pinching of the finger between the back wall  22  and the contact member  24 . Thus, the user can preferably insert a finger up to at least a point where the DIP crease contacts the free edge  21  of the contact member  24 . Alternately, each grip  14 ,  16  can be sized to receive the finger up to about a mid-point between the end extremity of the finger and the DIP joint, or a depth of about 1-2 cm. 
     Suitably, the finger cavity  19  of each grip  14 ,  16  has an elliptical cross section (as taken in a plane perpendicular to an axis of insertion  23  of the finger into the finger cavity  19 ) with a long (vertical) axis of about 3 cm and a short (horizontal) axis of about 2 cm. Alternatively, the finger cavity  19  can have a cylindrical cross-section having a diameter of about 2-3 cm, or another suitable cross-sectional configuration. 
     When mounting or removing the blanking panel  10 , it is necessary for the user to apply rearward or forward pressure to the blanking panel  10 . The grips  14 ,  16  provide a comfortable and secure means by which to apply such pressure. To mount or remove the blanking panel  10 , a user may securely and comfortably grip the blanking panel  10  by inserting an index finger (or any finger) into the finger cavity  19  of each grip  14 ,  16  from the front of the blanking panel  10  and gripping the associated contact member  24  between the inserted finger and the associated thumb. Alternatively, the user may employ a different combination of digits such as one or two fingers, or one thumb. 
     Referring to  FIGS. 7B &amp; 7C , standardized equipment racks or cabinet enclosures often have frame and door structure  200  that project laterally inward (about 2-4 cm) with respect to the outer ends  36 ,  38  of the blanking panel  10 , which, with prior blanking panels, requires the user to navigate their hands and fingers inside the frame and then laterally outward to the ends of the prior blanking panel to mount and remove the blanking panel. As depicted in  FIG. 7B , the mounting rails  210  of such racks commonly include integral or connected structure which extends forward, laterally outward of the mounting rails, such that a narrow gap  220  of about 1-2 cm (or less) exists between the outer ends  36 ,  38  of the blanking panel  10  and the forwardly extending portion  230  of the mounting rails. Such structure can substantially hinder or prevent a user from securely and comfortably grasping the ends  36 ,  38  of the prior blanking panel during mounting and removal. Thus, as can be appreciated, the structure of standardized racks and cabinet enclosures can result in undesirable, and uncomfortable or painful physical stress, abrasion, bumping, scraping or skinning contact of the user&#39;s hands or knuckles with the frame and/or mounting rails when attempting to mount or remove a prior blanking panel. 
     To overcome the above problems, and to provide a secure and comfortable grip, each grip  14 ,  16 , is disposed on the front of the blanking panel  10 . Further, each grip  14 ,  16 , or specifically the free edge  21  of the contact member  24  of each grip  14 ,  16 , is disposed laterally inward from an adjacent end  36 ,  38  of the blanking panel  10  a distance sufficient to allow the user to securely and comfortably grasp the grips  14 ,  16  while maintaining the users hands and forearms between the ends  36 ,  38  of the blanking panel  10  and between the frame and door structure of the rack. Specifically, the grips  14 ,  16  (or more specifically, the free edges  21  of the contact members  24 ) may be located laterally inward from the associated adjacent end  36 ,  38  of the blanking panel  10  at least about 5-15 cm, and preferably about 9 cm. With this configuration, the blanking panel  10  may be comfortably and securely mounted and removed in a rack or cabinet enclosure having limited or no clearance laterally outward of the ends  36 ,  38  of the blanking panel  10 , and/or a rack having laterally inwardly projecting frame or door structure, without any contact of the user&#39;s hands with the rails or cabinet enclosure. Further, the grips  14 ,  16  are preferably arranged symmetrically along a lateral axis of the blanking panel  10 . 
     To ensure proper alignment during mounting, the blanking panel  10  includes two pairs of rail alignment projections  32 ,  34 , each pair being located adjacent one of the opposed ends  36 ,  38  of the blanking panel  10 . The rail alignment projections  32 ,  34  extend from a rear surface  40  of the front wall  12  and are sized, shaped and spaced to align with and fit within holes in opposed mounting rails of the standardized rack. Each rail alignment projection  32 ,  34  is preferably tapered, such that an end extremity  42  has a smaller cross-section than a base portion  44  to facilitate such alignment. Other suitable shapes or configurations of the alignment projections are also within the scope of the invention. 
     Preferably, the rail alignment projections  32 ,  34  are sized and shaped to prevent any substantial movement of the blanking panel  10  when mounted, so as to maintain a proper seal provided by the blanking panel. Preferably, the mounted blanking panel  10  will move no more than about 0.005 inches to about 0.030 inches, and preferably no more than about 0.020 inches in either the horizontal (lateral) or vertical direction. 
     The blanking panel  10  also includes a pair of snap-mount or friction-fit rail engagement members  46 ,  48  located laterally inward of the rail alignment projections  32 ,  34 . The rail engagement members  46 ,  48  extend from the rear surface  40  of the front wall  12 . Each rail engagement member  46 ,  48  is resiliently cantilevered from the rear surface  40  of the front wall  12  and includes a laterally outward projecting apex  50  which engages a laterally inward facing surface of an associated mounting rail to secure the blanking panel  10  to the rack. 
     Preferably, the rail alignment projections  32 ,  34  extend from the rear surface  40  of the front wall  12  a distance greater than the rail engagement members  46 ,  48  such that the rail alignment projections  32 ,  34  enter the holes in the mounting rails prior to engagement of the rail engaging members  46 ,  48  with the mounting rails, so that the user may, during the initial process of mounting, reliably obtain a proper alignment of the blanking panel  10  with the rack and may, in the final process of mounting, maintain such proper alignment while applying mounting pressure to mount the blanking panel  10 . 
     Referring to  FIGS. 4A-6 , the blanking panel  10  is configured for stacking of multiple blanking panels during shipping and storage. A pair of stacking supports  52  is located between skirt members  60 ,  62  (described in detail below, and depicted in  FIGS. 7A-8 ), which skirt members have end extremities  68 ,  70  that extend along substantially the entire length of the blanking panel  10 . The stacking supports  52  extend from the rear surface  40  of the front wall  12  or from the back wall  22  of the grips  14 ,  16  between the skirt members  60 ,  62 . When stacked, the stacking supports  52  and/or the rail alignment projections  32 ,  34  of an upper blanking panel contact the front wall  12  and/or the contact members  24  of the immediately lower blanking panel to orient and stabilize the upper blanking panel on top of the lower blanking panel. 
     To stack the blanking panels  10  in a stable manner, a lower blanking panel can be placed face-up (i.e., front wall  12  up) on a horizontal support surface, such as a horizontal floor, table surface or shelf, resting on the skirt members  60 ,  62  and/or the end extremities  42  of the rail alignment projections  32 ,  34 . In this orientation, a lateral (i.e., end-to-end) axis of the lower blanking panel is substantially parallel to the support surface and is therefore substantially horizontal (this lateral axis may be considered an X axis). Then, an upper blanking panel may be placed face-up on top of the lower blanking panel. When properly stacked, the stacking supports  52  and/or the end extremities  42  of the rail alignment projections  32 ,  34  of the upper blanking panel support the upper blanking panel with a lateral (X) axis thereof substantially parallel to the corresponding X axis of the lower blanking panel (i.e., substantially horizontal). Further, the stacking supports  52  positively orient the upper blanking panel along the lateral (X) axis relative to the lower blanking panel, with the end portions  36 ,  38  of the upper and lower blanking panels in substantial vertical alignment (i.e., the upper blanking panel directly above the lower blanking panel). Moreover, the stacking supports  52  prevent relative movement (i.e., translation) between the upper and lower blanking panels along the X axis, such that the ends of the upper and lower blanking panels remain in substantial alignment. The stacking supports  52  and/or the end extremities  42  of the rail alignment projections  32 ,  34  also orient the upper blanking panel along a horizontal axis perpendicular to the X axis (this may be considered a Y axis), and limit or prevent relative movement of the upper and lower blanking panels along the Y axis. 
     Additional blanking panels may be stacked on top of the above-described two-piece stack in a likewise manner. The stacking supports of the additional blanking panels restrict movement of the additional blanking panels with respect to the stack below. It has been found that the stacking support arrangement of the invention, which restricts movement of the blanking panels in the two orthogonal horizontal axes (i.e., the X and Y axes) enables the stacking of about 10 pieces of 1 U blanking panels of the present invention in a stable manner, or about 25 pieces of 2 U versions thereof, without the need for additional support from a container or other fixture or device. Further, it is possible to create stable stacks of blanking panels of various sizes. For example 2-1 U pieces may be stacked on top of (or below) a single 2 U piece, and 2-1 U pieces and a 2 U piece could be stacked on top of (or below) a 4 U piece, etc. It can be appreciated that many other stack configurations are also possible. 
     While the face-up stacking method described above is preferable for stacking blanking panels depicted in  FIGS. 1-9 , it is within the scope of the invention to stack blanking panels in a face-down orientation, if the front of the blanking panel is flat or is otherwise configured to support the blanking panel on a horizontal support surface with the X and Y axes substantially horizontal. This is particularly true for blanking panels of 2 U size or greater since the apexes of the free edges  21  of the contact members  24  of multi-U versions of the blanking panel provide well-spaced and stable contact points on the support surface. 
     Each stacking support  52  preferably includes a first portion  54  positioned and shaped to engage the contact member  24  of the lower blanking panel. The first portion  54  may extend from the rear surface  41  of the back wall  22  a set-off distance sufficient to prevent contact of the rail alignment projections  32 ,  34  of the upper blanking panel with the front wall  12  of the lower panel, such that, when stacked, the upper blanking panel rests on the nested stacking supports  52 . The first portion  54  preferably has a concave shape complimentary to the convex shape of the exterior surface  29  of the contact member  24 , to properly align and stabilize the upper blanking panel with the lower blanking panel, along the Y axis, perpendicular to the lateral (X) axis of the blanking panel. 
     Alternatively, the first portion  54  of each stacking support  52  and the rail alignment projections  32 ,  34  of the upper blanking panel may contact the lower blanking panel when stacked. As a further alternative, the rail alignment projections  32 ,  34  may extend from the rear surface  40  of the front wall  12  a distance sufficient to prevent contact of the first portion  54  of each stacking support  52  with the lower blanking panel such that the upper blanking panel rests on the rail alignment projections  32 ,  34 . In this further alternative, the first portion  54  of each stacking support  52  preferably closely surrounds the associated contact member  24  to align and stabilize the upper blanking panel with respect to the lower blanking panel. 
     Each stacking support  52  also preferably includes a second portion  55 , located laterally inward of the first portion  54 , which second portion  55  extends further from the rear surface  41  of the back wall  22  than the first portion  54 . The second portion  55  is positioned to extend into the finger cavity  19  of a lower, stacked blanking panel, immediately adjacent the free edge  21  of the contact member  24 , to align and stabilize the upper blanking panel with the lower blanking panel, along the lateral (X) axis. 
     Stacking stability of the blanking panels  10  is further enhanced by the fact that the curvatures of the contact members  24  and the front wall  12  are non-concentric. Thus, the upper blanking panel  10  is inhibited from rotating (about the X axis) with respect to the lower blanking panel  10 . Specifically, two contact areas of the front wall  12  of the lower blanking panel  10  contacted by the end extremities  42  of the rail alignment projections  32 ,  34  of the upper blanking panel  10  are preferably convex in shape. Further, the areas of the contact members  24  contacted by (or immediately below) the first portions  54  of the stacking supports  52  of the upper blanking panel  10  are also preferably convex in shape. However, the contact members  24  have a radius of curvature substantially smaller than the radius of curvature of the contact areas of the front wall  12 . Further, the contact areas of the front wall  12  have centers of curvature substantially displaced from centers of curvature of the areas of the contact members  24  contacted by (or immediately below) the first portions  54  of the stacking supports  52 . Preferably, the centers of curvature of the areas of the contact members  24  contacted by the first portions  54  of the stacking supports  52  lie somewhere between the associated contact member  24  and a plane defined by the end extremities  68 ,  70  of the skirt members  60 ,  62  (described in detail below), whereas such plane is between the centers of curvature of the contact areas of the front wall  12  and the contact members  24 . Since the centers of curvature are non-concentric, the upper blanking panel  10  is inhibited from rotating about the X axis with respect to the lower blanking panel, which imparts significant stability to a vertical stack of blanking panels. 
     Referring to  FIG. 7A-8A , to prevent the flow of air between the blanking panel  10  and other conforming devices (i.e., electronic devices or blanking panels) immediately above and below, the blanking panel  10  preferably includes bottom and top rearwardly projecting skirt members  60 ,  62  which extend along substantially the entire lateral length of the blanking panel  10 . Preferably, each skirt member  60 ,  62  has a lateral length sufficient to extend substantially entirely between the mounting rails of the rack or cabinet enclosure for which it is designed. 
     The top and bottom skirt members  60 ,  62  are resiliently flexible and project divergently rearward from top and bottom edges  64 ,  66  of the blanking panel  10 , respectively. The height of the front of the blanking panel (including any upper and lower edges  64 ,  66  thereof) is substantially equal to or slightly less than one of the standardized heights of the rack or cabinet enclosure (e.g., 1 U, 2 U, 3 U, . . . nU, less about 0.040 inches). However, the outer edges  97 ,  98  of the end extremities  68 ,  70  of the skirt members  60 ,  62  are preferably spaced apart a predetermined distance greater than the standardized height of the blanking panel  10  such that the skirt members  60 ,  62  make resilient contact with, and sealingly interfere with another conforming device immediately above or below the blanking panel  10 , to substantially prevent air flow therebetween, while permitting smooth mounting and removal of the blanking panel  10  from the rack or cabinet enclosure. 
     Preferably, the outer edges  97 ,  98  of the end extremities  68 ,  70  of the skirt members  60 ,  62  are spaced apart about 0.040 to about 0.080 inches (most preferably about 0.065 inches) greater than an integer multiple of the standard height of the rack or cabinet enclosure (e.g., nU+about 0.065 inches), which ensures a substantial sealing interference (of about 0.020 to about 0.040 inches, and preferably about 0.033 inches) with adjacent conforming devices, prior blanking panels, and sealing blanking panels (constructed according to the present invention), while accommodating expected manufacturing variances in each skirt member  60 ,  62 . For example, if the blanking panel is of a 1 U size and 1 U is equal to about 1.75 inches, the outer edges  97 ,  98  may be spaced about 1.82 inches apart. 
     Preferably, mid points between the outer and inner edges  97 ,  97 ′ and  98 ,  98 ′ of the end extremities  68 ,  70  are spaced apart a distance substantially equal to the standard height of the blanking panel  10  (e.g., 1 U, 2 U, etc.). Therefore, as described above, the outer edges  97 ,  98  of the end extremities are spaced a predetermined distance apart greater than the standard height of the blanking panel  10 , creating an interference of about half the thickness of the end extremity  68 ,  70  with an adjacent standard-height device or blanking panel to provide sealing interference between the blanking panel  10  and the adjacent devices (or other blanking panels). 
     As can be appreciated, the interference between two adjacent sealing blanking panels  10  constructed according to the present invention will be double that of the interference between one sealing blanking panel  10  and a standard-height device or a prior blanking panel. However, the resilient flexibility of the skirt members  60 ,  62  of the two adjacent sealing blanking panels  10  is sufficient to permit smooth mounting and removal of each sealing blanking panel  10 . 
     Referring to  FIG. 8A , each skirt member  60 ,  62  has a living hinge creating an area of flexure  90  disposed between the associated bottom or top edge  64 ,  66  of the front of the blanking panel  10  and the associated end extremity  68 , 70  of the skirt member  60 ,  62 . Each area of flexure  90  has a relatively reduced, and preferably substantially constant, thickness of about 0.025 to about 0.040 inches, most preferably about 0.030 inches, which area of flexure  90  extends rearward about 0.100 to about 0.200 inches, most preferably about 0.150 inches. The area of flexure  90  provides a fatigue-resistant area about which the skirt member  60 ,  62  resiliently flexes when engaging an adjacent blanking panel or electronic device in the rack or cabinet enclosure. 
     Each skirt member  60 ,  62  preferably has a forward area (A)  92  extending from an associated bottom or top edge  64 ,  66  to the area of flexure (B)  90 , which forward area  92  has a relatively increased thickness of about 1.8 to about 2.3 mm. Each skirt member  60 ,  62  also has a rearward area (C)  93  extending from the area of flexure (B)  90  to the associated end extremity  68 ,  70  of the skirt member  60 ,  62 , which rearward area  93  has a gradually increasing thickness, from about 0.6 mm to about 1.2 mm adjacent the area of flexure  90 , to about 1.3 mm to about 1.8 mm (about 0.060 inches) at the end extremity  68 ,  70 . 
     As can be appreciated, the seal provided by the skirt members  60 ,  62  does not require the user to disassemble any adjacent electronic components or blanking panels. The blanking panel  10  is simply inserted into the rack or cabinet enclosure in the open mounting location between the adjacent devices. The resilient skirt members  60 ,  62  compress upon engagement with the adjacent devices providing a seal therebetween. Likewise, no disassembly of the adjacent devices is required to remove the blanking panel. 
     Referring to  FIG. 8B , to further aid in sealing, the skirt members  60 ,  62 , or at least an outer surface thereof, may include an over-mold of a relatively pliant material  410 , such as a natural or synthetic rubber, or an elastomer thermoplastic such as a polyolefin, fluoropolymer, vinyl, or a like material having a Shore A Durometer reading of about 50 to about 180. Preferably, the over-mold has a thickness of about 0.020 to about 0.060 inches and is substantially more pliant than the material comprising the remainder of the blanking panel. 
     Referring to  FIG. 8C , end portions  568 ,  570  of the skirt members  60 ,  62  of the blanking panel  10  may be constructed of a pliant material  510  (as described in reference to  FIG. 8B  above), which is joined to (harder, less pliant) base portions  590  of the associated skirt member by an overmold  520 , which overmold may be at an approximate midpoint of the skirt member  60 ,  62 , or may be adjacent to (or slightly rearwardly of) the bottom and top edges  64 ,  66 . Preferably, the pliant material of the skirt members  60 ,  62  has a thickness of about 0.015 inches to about 0.125 inches, and most preferably about 0.060 inches. 
     As above, the end extremities  68 ,  70  of the skirt members  60 ,  62  are spaced apart about 0.040 to about 0.080 inches (most preferably about 0.065 inches) greater than an integer multiple of the standard height of the rack or cabinet enclosure (e.g., nU+about 0.065 inches). Further, the pliant end portions  568 ,  570  of the skirt members  60 ,  62  preferably have an arcuate cross section (perpendicular to the lateral, X axis) which is concave in the upward direction for the top skirt  62  and in the downward direction for the bottom skirt  60 , such that the pliant end portions diverge in a rearward direction. The arcuate configuration and pliant material of the end portions  568 ,  570  provide enhanced sealing between the blanking panel and an adjacent conforming device. Preferably, the configuration provides sealing contact between the skirts and an adjacent compliant device along an area having a front-to-back dimension of about 0.010 inches to about 0.115 inches, and most preferably about 0.10 inches. This area may be defined in part by the end extremities  68 ,  70  of the skirt members  60 ,  62  and by at least the associated overmold  520 . Thus, the sealing between the blanking panel and an adjacent device occurs over a band or region, which creates a substantial and highly effective seal. 
     Referring to  FIGS. 9-10 , the blanking panel  10  may optionally include an ambient air temperature indicating strip  80 , such as a liquid-crystal display (LCD) temperature indicating strip, affixed to a mounting surface  85  of an off-set platform  82  mounted to the front wall  12  and/or contact members  24  of the blanking panel  10 . Suitably, the off-set platform may have a lateral end-to-end length of about 263 mm to about 275 mm, and preferably about 270 mm. 
     The off-set platform  82  is preferably connected to the front wall  12  by a pair of end connectors  83 , and by a plurality of (e.g., two) intermediate connectors  87 , which are located at intervals between the end connectors  83 . The off-set platform  82  is set off a predetermined off-set distance from the front wall  12  (e.g., about 5 mm to about 7 mm) along a majority of a lateral length thereof, such that there exists an elongated air-flow passage or passages  88  between the off-set platform  82  and the front wall  12  of the blanking panel  10 . The off-set distance prevents any (or any substantial amount of) conductive heat transfer between the front wall  12  and the mounting surface  85  of the off-set platform  82 . Further, the air-flow passage(s)  88  permit ambient air to flow between the front wall  12  of the blanking panel  10  and the off-set platform  82 , such that the effect of any radiative or convective heating of the off-set platform  82  by the front wall  12  of the blanking panel  10  is virtually eliminated. Thus, the temperature of the mounting surface  85  most closely indicates the temperature of the ambient air, as opposed to the temperature of the front wall  12  of the blanking panel  10 , which may be influenced by the temperature of the equipment rack, the cabinet enclosure or the air therewithin. Therefore, a temperature indicating strip  80  affixed to the mounting surface  85  will accurately display the temperature of the ambient air. 
     Referring to  FIG. 6 , preferably, when upper and lower blanking panels  10  are stacked, extreme lateral ends  84 ,  86  of the off-set platform  82  of the lower blanking panel  10  are located intermediate points at which the stacking supports  52  of the upper blanking panel  10  contact the lower blanking panel such that the off-set platform  82  does not interfere with or prevent nested stacking of the blanking panels  10 . 
     In addition to or instead of the air temperature indicating strip  80 , the blanking panel  10  can include a variety of other devices mounted to or within the front wall  12 , such as, for example, a writing surface, signage, a humidity indicator, an electronic display or a pair of opposed, elongated brushes, elastomer, sponges, or other material for permitting the passage of cables therethrough, while simultaneously controlling air flow through the blanking panel  10 . If the blanking panel  10  includes such a cable pass-through, both the front wall  12  and the off-set platform  82  preferably have a cable pass-through to guide the cables through the blanking panel  10 . 
     Referring to  FIGS. 11-13 , an alternative embodiment of the blanking panel  110  has grips  114 ,  116  comprising an adjacent pair of recesses  118 ,  118 ′ formed in and projecting rearward from the front wall  112  of the blanking panel  110 . Each recess  118 ,  118 ′ is sized and shaped to receive a finger or thumb of a user therein. Preferably, the recesses  118 ,  118 ′ are substantially D-shaped and reverse D-shaped (as viewed from the front), and are disposed in an adjacent, mirrored arrangement, such that the straight (vertical) lines of the two D&#39;s closely abut one another. 
     A contact member  124  is disposed between each pair of recesses  118 ,  118 ′. The contact member  124  preferably extends from a bottom  122 ,  122 ′ of each recess  118 ,  118 ′ substantially to a plane of the front wall  112  of the blanking panel  110 . Each contact member  124  includes a laterally outward surface  127 , which forms a finger bearing surface  128 , and a laterally inward surface  129 , which forms a thumb bearing surface  130 . 
     As described above, each finger bearing surface  128  is sized to engage a majority of the palmar aspect of the fingertip of the user beyond from about the DIP joint of the finger to about the end extremity of the finger, or, alternatively, beyond from about a mid-point between the DIP joint to about the end extremity of the finger. The thumb bearing surface  130  is sized to engage a majority of a palmar aspect of the thumb of the user beyond from about the DIP joint of the thumb to about the end extremity of the thumb, or, alternatively, beyond from about a mid-point between the DIP joint and the end extremity of the thumb. 
     The finger and thumb bearing surfaces  128 ,  130  may be substantially planar, and substantially parallel. Alternatively, the finger and thumb bearing surfaces  128 ,  130  may diverge in a forward direction (i.e., from the bottom  122 ,  122 ′ of the recesses  118 ,  118 ′ toward the front wall  112 ), to provide an enhanced grip between the finger and thumb. 
     Also as described above, each grip  114 ,  116 , or the contact member  124  of each grip  114 ,  116 , is preferably disposed laterally inward from an associated end  136 ,  138  of the blanking panel  110  at least about 5-15 cm, and preferably about 10 cm, such that a user may securely and comfortably grasp the grips  114 ,  116  while maintaining the users hands and forearms between the ends  136 ,  138  of the blanking panel  110 . Further, the grips  114 ,  116  are preferably arranged symmetrically along a lateral axis of the blanking panel  110 . 
     Referring to  FIG. 14 , a blanking panel  310  provided in a 2 U size preferably has a pair of grips  314 ,  314 ′ and  316 ,  316 ′ at each end  336 ,  338 . Similarly, the 2 U blanking panel preferably has, at each end  336 ,  338  thereof, a pair of stacking supports (not shown), a pair of rail engagement projections  348 , and a pair of rail alignment projections  332 ,  334 . However, the 2 U blanking panel may have, at each end  336 ,  338  thereof, only one grip  314 ,  316 , and/or only one stacking support, and/or only one rail engagement projection  348 , and/or only one rail alignment projection  332 ,  334 . In any configuration, however, the 2 U blanking panel preferably has one set of (top and bottom) skirt members  360 . It can be appreciated that other sizes of the blanking panel (e.g., 4 U, 8 U, etc.) constructed according to the invention may have similar configurations. 
     It should be understood, of course, that the specific form of the invention herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.