Abstract:
A latch and release mechanism releasably secures a panel in a computer housing. The mechanism includes a latch member on a panel of the housing and hole on a front chassis segment of the housing. The hole receives the latch member to secure the panel to the body. A release member applies pressure to the latch member to disengage the latch member from the hole and release the panel from the front chassis.

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a latch and release mechanism for a panel of a computer hardware device, and in particular although not exclusively to such a mechanism for an access, or front, panel of a personal computer.  
         BACKGROUND OF THE INVENTION  
         [0002]    Personal computers (PCs) use storage devices, such as floppy disc drives, CDROM drives, DVD drives and hard disk drives, and other modules, which can be upgraded or replaced by the end user. In general these devices are accessible from the front of the PC after removal of a front panel, often referred to as a bezel. The invention relates to a structure for selectively holding and releasing the front panel from the PC.  
           [0003]    PCs generally include a main chassis frame, and a front chassis, secured together, and to which is releasably secured the front panel. The most common structure for retaining the front panel in such PCs incorporates a latch and release mechanism as follows. The front panel is molded from plastic with a pair of integral latch members spaced apart adjacent the top of the panel, and a pair of integral spring ribs spaced apart towards the bottom of the panel. Each latch member includes a hook including a ramp surface and an engagement surface. The front surface of the front chassis of the PC has a pair of holes towards the bottom thereof, each hole is for receipt of a spring rib. The upper surface of the front chassis has a pair of spaced apart holes for receipt of the latch members.  
           [0004]    To install the front panel the spring ribs are located in the respective holes, and the panel is pivoted upwardly and inwardly such that the ramp surfaces of the latch members contact the front edge of the front chassis and are then forced upwardly, causing bending of the latch members in the process. Each latch member thus rides up over the front chassis until the hook has passed the front edge of the respective hole, thereby enabling the spring bias of the latch member to return the latch member to its initial unbent condition and the hook to fall into the hole. Each engagement surface then engages with the front edge of the respective hole to retain the front panel securely in place. Thus installation of the front panel is a simple process which is also readily achieved by the end user.  
           [0005]    To remove the front panel is also in essence simple, but is however not so readily achieved. First, it is not readily apparent to a user of the PC how to release the front panel, as the latch members are very small and not specifically identified in any way. Second, to remove the panel requires each latch member to be lifted up to remove the hook formation from within the respective hole (see FIG. 1), with both being lifted simultaneously, thus permitting the front panel to be pivoted forwardly and downwardly. To lift the latch members using only the fingers of a user is very difficult due to the small access area and the stiff plastic from which the latch members are made. However, to lift both latch members simultaneously using tools is also not readily achieved.  
           [0006]    An alternative known in the prior art, and particularly appropriate for tower PCs, is described in U.S. Pat. No. 5,997,115. In this design the latch and release mechanism is secured to the chassis, rather than the front panel, and has a single point where a user must push down to release the front panel. However, to achieve this easier release the mechanism is remarkably complex and thus costly to manufacture. It is also unlikely that the design could be adapted for use in a standard form factor housing rather than tower PCs, due to the greater separation between the latch members in such PCs.  
           [0007]    It is an object of the present invention to provide a new and improved access latch and release mechanism for a panel which mitigates the above identified problems.  
         SUMMARY OF THE INVENTION  
         [0008]    In accordance with one aspect of the invention a computer hardware device comprises a panel having a hook member and body having a first part and a second part. The first part of the body includes a hole for receipt of the hook member and the second part underlies the first part at the location of the hole. A release member is arranged such that pressure applied to a first part of the release member causes a second part of the release member to act on the hook member to disengage the hook member from the hole and release the panel from the body of the computer hardware device. The first part of the release member includes a bearing surface and the second part of the release member includes a contact surface. The release member is pivotally mounted such that pressure applied to the bearing surface pivots the release member and the contact surface pushes the hook member out of the hole. The release member is located between the first and second parts with the bearing surface being visible and accessible to a user through a second hole in the first part.  
           [0009]    This latch and release mechanism provides the advantage that the panel can be removed by application of pressure on a readily accessible part of the release member. Depending on the location of the latch and release mechanism the pressure can be applied downwardly or inwardly, but in any event no lifting of any part is required.  
           [0010]    Preferably the release member includes a pivot element which fits in a recess in the second part of the body.  
           [0011]    Preferably the bearing surface and contact surface are on the upper side of the release member and the pivot element is on the lower side of the release member at a mid point thereof.  
           [0012]    The structure of the body of the computer hardware device is typically such that the first part of the body is a front chassis, and the second part of the body is a chassis frame.  
           [0013]    Preferably the release member is formed of plastics material of a contrasting color to the body of the computer hardware device and/or the panel.  
           [0014]    The panel is preferably formed of plastics material with the latch members integrally molded and the body of the computer hardware device is formed of metal.  
           [0015]    According to a second aspect of the invention a computer hardware device has a panel and a body and includes one or more latch and release mechanism (according to the first aspect of the invention) for releasably securing the panel to the body. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    An example of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:  
         [0017]    [0017]FIG. 1, as previously mentioned, is a perspective view of a prior art latch and release mechanism as applied to a standard housing of a PC;  
         [0018]    [0018]FIG. 2 is a perspective view of a latch and release mechanism of a preferred embodiment of the present invention, as applied to a housing of a PC having a standard form factor;  
         [0019]    [0019]FIG. 3 is a close up of the relevant portion of the PC illustrated in FIG. 2, showing the latch and release mechanism more clearly;  
         [0020]    [0020]FIG. 4 is an exploded view of the relevant portion of the PC of FIGS. 2 and 3;  
         [0021]    [0021]FIG. 5 is a vertical cross sectional view through the latch and release mechanism of the PC of FIGS.  2  to  4 , wherein the view is parallel to the front of the PC of FIGS.  2  to  4 ;  
         [0022]    [0022]FIG. 6 is a vertical cross sectional view through the latch and release mechanism of the PC of FIGS.  2  to  5 , perpendicular to the front of the PC of FIGS.  2  to  5 ;  
         [0023]    [0023]FIG. 7 is a perspective view of the inside of the front panel of the PC of FIGS.  2  to  6  showing the parts of the latch and release mechanism; and  
         [0024]    [0024]FIG. 8 is a perspective view of a release member of the latch and release mechanism of the PC of FIGS.  2  to  7 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    FIGS.  2  to  8  include a latch and release mechanism applied to PC  10  having a housing with a standard form factor. The PC  10  comprises a chassis frame  12  and a front chassis  14  secured together by threaded fasteners to form a chassis, and a front panel  16  releasably secured to the front chassis  14  by means of two pairs of latch and release mechanisms.  
         [0026]    The front panel  16  comprises an upper part  16   a  and a lower part  16   b  (FIG. 3). The upper part  16   a  includes a pair of spaced apart first latch members  18  in proximity to the opposite edges of PC  10 . Each of latch members  18  has at its distal end a hook formation (FIGS. 6 and 7) including a ramp surface  20  and an engagement surface  22 . Upper front panel part  16   a  also includes a pair of spaced apart spring ribs  24  (FIGS. 6 and 7) (only one of which is shown) that are in proximity to the edges of PC  10 , but inside of hook members  19 . Spring ribs  24  serve as location members for front panel  16  relative to front chassis  14 . The lower part  16   b  of the front panel  16  includes a pair of spaced apart second latch members  25  (FIG. 7) (only one shown), each having a downwardly oriented hook formation  27  at its distal end. Latch members  25  are approximately vertically aligned with latch members  18  and assist in properly locating front panel  16  on front chassis  14 . First and second parts  16   a ,  16   b  of the front panel  16  are molded from plastics material and the latch members  18 ,  25  and spring ribs  24  arc provided as integral parts of the moldings.  
         [0027]    The front chassis  14  includes a first pair of spaced apart holes  26  (FIGS. 4 and 6) (only one shown). Holes  26  are on the upper surface of chassis  14  adjacent the front thereof, and towards the outer edges thereof. The front chassis  14  also includes, on its upper surface and located inwardly of each of the first holes  26 , a second pair of spaced apart holes  28  (FIG. 4) (only one shown). Front chassis  14  also includes, on its front surface, towards the bottom thereof, a third pair of spaced part holes  30  (FIG. 4) (only one shown). Holes  30  are conveniently located substantially beneath the first pair of holes  26 , and are positioned to receive hooks  27  of latch members  25 .  
         [0028]    The front panel  16  is secured to the front chassis  14  by placing hooks  27  of second latch members  25  in the third pair of holes  30 , and then pivoting the front panel  16  upwardly and inwardly such that the first latch members  18  contact the front edge of the upper surface of the front chassis  14 . This action causes the ramp surfaces  20  to ride up and over the upper surface of the front chassis  14 , thus bending the first latch members  18  until the hook formations  19  drop into the first holes  26 , whereby the first latch members  18  return to their original straight condition. The engagement surfaces  22  then engage the front edge of the holes  26  to prevent the front panel  16  from being removed from the front chassis  14 . When the front panel  16  is secured to the front chassis  14  the spring ribs  24  contact the front chassis  14  and create a slight pressure that tends to push chassis  14  from panel  16 . This pressure prevents the front panel  16  from rattling and aids in removal of the front panel  16  as described later. This arrangement is substantially as in the prior art of FIG. 1.  
         [0029]    Each latch mechanism  18  is associated with a release member  32  (FIGS. 4, 5 and  8 ). The upper surface at a first end of release member  32  includes a bearing surface  34  which is preferably textured, e.g. ribbed, to prevent a user&#39;s finger from slipping when bearing down on surface  34 . The upper surface of the other end of release member  32  includes contact surface  36 , which is conveniently of domed form. In a mid portion of the release member  32 , mid on it&#39;s lower surface, is a pivot element  38  conveniently in the form of, a rounded rib running across the release member  32 .  
         [0030]    Each latch and release mechanism including latch  18  and release member  32  is associated with a pair of recesses  40  (FIG. 4) (only one shown) on the upper surface of the chassis frame  12  adjacent the front thereof. Each of recesses  40  is located between the respective first and second holes  26 ,  28  in the front chassis  14 .  
         [0031]    Each release member  32  is located between the upper surface of the front chassis  14  and the upper surface of the chassis frame  12 , with the pivot element  38  located in the recess  40 . Each bearing surface  34  is located in the respective second hole  28  and the contact surface  36  is located beneath the ramp surface  20  of the respective catch member  18  in first hole  26 .  
         [0032]    To release the front panel  16  from the body comprising chassis  12  and  14  of the PC  10 , the user simply pushes down on each of the bearing surfaces  34 , as illustrated by arrows A in FIG. 2. Doing so causes the release members  32  to pivot about the pivot elements  38  such that the first end (where bearing surfaces  34  are located) of each release member  32  moves downwardly towards the chassis frame  12  and the other end of each member  32  (where contact surfaces  36  are located) moves upwards away from the chassis frame  12 . Thus the contact surfaces  36  bear up on the ramp surfaces  20  of the first latch members  18 , to bend the first latch members  18  and lift the hook formations  19  upwards and out of the first holes  26 . The engagement surfaces  22  are thus no longer engaged on the front edges of the holes  26  and the front panel  16  can be pivoted forwardly and downwardly, aided by spring ribs  24 , until the hook formations  19  are clear of the front chassis  16 , resulting in the first latch members  18  returning to their original straight condition. The second latch members  25  are then removed from the third holes  30  to remove the front panel  16  from the chassis of the PC.  
         [0033]    Thus the described latch and release mechanism provides a very simple and user friendly operation for the removal of the front panel of a PC. Furthermore the mechanism is very simple to manufacture, requiring very little modification of the prior art, and thus being cost effective to implement. In particular the front panel  16  requires no modification whatsoever, while all that is required to be changed in the front chassis  14  and chassis frame  12  are the addition of a pair of additional holes  28  and a pair of recesses  40  respectively. As the front chassis  14  and chassis frame  12  are generally made of steel which is formed by pressing from sheet, these minor features are readily added. The only extra components required for the latch and release mechanisms are the release members  32 , which are very simple plastic molded parts, and are an identical pair that do not require handling. In addition, the assembly of the PC with the latch and release mechanisms is also very simple and does not require any additional fastenings.  
         [0034]    Preferably the release members  32  are molded from plastics material of a contrasting color to that of the other components of the PC against which it is seen in use, in particular the front chassis  14 . The contrasting color makes it easier for the user to realize how to remove the front panel  16 , and in particular the relevant locations where pressure is to be applied to effect that removal.  
         [0035]    Additional assistance for the user is provided by pressing small arrow shapes  42  into the upper surface of the front chassis  14  adjacent to and pointing towards the second holes  28 , in order to draw attention to the bearing surfaces  34  of the release members  32  visible through those holes. Such arrows are readily included in the pressing operations involved in forming front chassis  14 .  
         [0036]    Although the latch and release mechanisms have been described as applied to the front panel of a PC they are clearly also applicable to other computer hardware devices where the end user might require access, such as for example a printer, or indeed to other kinds of electronic equipment.  
         [0037]    In alternative applications, latch and release mechanisms as described can be provided in different positions with respect to the computer hardware device. For example, one or two latch and release mechanisms can be located on each side of a computer, rather than a pair on the top. There may also be applications where a single latch and release mechanism as described could be employed.  
         [0038]    A further alternative is the provision of the latch members on the chassis, or other body of the computer hardware device, and the provision of the holes or other engagement formations on the panel.  
         [0039]    The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed invention, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilized for realizing the invention in diverse forms thereof.