Abstract:
A system to mount several electronic devices within a one EIA unit high rackspace is presented. The system includes a mounting chassis that is securely fastened to a standard 19″ EIA electronics rack. The chassis includes dividers that define at least two full length ports in which the electronic devices are slidably engaged. Furthermore, each port defined by the mounting tray includes hot-pluggable, blind-mate sockets to receive corresponding hot-pluggable, blind-mate connectors upon each electronics package. These packages are engaged and disengaged to and from the ports within the rack at will, thus allowing for more servers to be efficiently and accessibly stored within the confines of a 1-U rackspace with interchangeability than was previously possible.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
         [0001]    Not Applicable.  
         TECHNICAL FIELD OF THE INVENTION  
         [0002]    The present invention relates to a structural method of arranging electronic packages within a standard electronics rack housing. More particularly, the present invention relates to a system of arranging electronic packages within an electronics rack so that rack space is used more efficiently and that rapid exchanges of the electronics packages is possible.  
         BACKGROUND OF THE INVENTION  
         [0003]    The necessity for specialized computer equipment has increased dramatically over recent years. Corporations, both large and small, as well as individual consumers have come to depend on computers to enhance and assist them in a broad assortment of tasks. For the individual or small business, personal computers are typically relatively compact and streamlined, often comprising a monitor, a keyboard, a mouse, and a CPU “box” that sits on a desktop or on the floor. These personal computers, although considered compact when deployed in relatively small numbers, can be quite cumbersome and bulky when deployed in larger quantities. It is not uncommon for an organization to require several computers to act as servers controlling their local area networks. Even the networks of small companies ran more efficiently when specific tasks are up among individual servers. Typically, the small company will have a room with several servers, all in standard CPU cases consuming a significant amount of space.  
           [0004]    For larger corporations that require numerous servers, the traditional CPU package is not practical to house servers. Larger companies, especially “e-businesses” that use the internet and the world wide web to conduct their commerce, require a higher number of servers than that required by smaller businesses. Such organizations, and in particular the internet service providers, or ISPs, must be able to pack far more server appliances within a limited amount of space than would be conceivable using traditional desktop chassises. For such operations, an industry standard EIA (Electronics Industries Alliance) rack is often used to contain servers in a stacked arrangement that uses the available space more efficiently.  
           [0005]    Such electronics racks are a relatively simple structure that closely resemble an open-frame bookcase without shelves. Computer server/component racks are typically constructed with perforated, hinged front-doors, rigid sides and a removable rear panel. Often, the rear panel of an electronics rack is constructed as a hinged, perforated door that is allowed to be opened and swung out of the way when access from the rear is desired. Within the rack exterior, or “shell,” formed by the sides and back panel is a structural frame. The rack frame is capable of supporting the weight of the electronics contained within the rack and serves as the primary means of securing components therein. The rack frame, closely resembles an industrial shelving unit and typically includes four rigid corner posts, connected to each other with a plurality of cross members and structural supports. Each of the four corner posts include a plurality of mounting holes, though which electronic components can be secured.  
           [0006]    Industry standard 19″ EIA electronics racks are designed typically to house a column of electronics packages that are 17¾″ in width and with varying depths. The height of an electronics package can vary but, to be compatable with the rack mounting structure, must be an integer multiple of an EIA unit called simply the “U.” An EIA U is 1.75 inches. Electronic equipment, generally has a height in multiples of “U&#39;s” e.g., 1 U (1.75″), 2 U (3.50″), 3 U (5.25″), etc. A piece of equipment whose height is not an integer multiple of a U will not efficiently use rack space. Standard equipment racks are available in a wide assortment of heights, but the most common is of 42 U height.  
           [0007]    Typically, electronic packages are mounted in the rack from the front and secured in place with fasteners, specifically thumbscrews. The thumbscrews allow frequent installation and removal of the electronic packages with minimal effort and without hand tools. Power and data connections are preferably made by opening the rear panel of the rack and accessing the rear surface of the mounted device. If a piece of equipment is heavy or does not include features that allow it to be secured properly to the rack, a rack shelf can be secured in place to the rack frame to support the non-standard device. Alternatively, electronic components may be secured within the rack using a pair of drawer slides. The drawer slides, usually ball-bearing supported rails, are secured in place within the rack frame. Corresponding rails are located on the side surfaces of the electronics component to be mounted, thus allowing the component to be pulled in and out of the rack frame easily to allow quick and frequent access.  
           [0008]    Although it is preferred that the height of the electronics components be a multiple of the standard EIA unit U, the dimension of the EIA unit is understood to represent a maximum allowable height. Two adjacent 1 U height electronic devices will require a finite amount of clearance. This amount of clearance aides in the installation of the rack mounted electronics and promotes interference free insertion and removal. For a device that is much less heat intensive, for example an internet server, an overall height of 1.65″ (with 0.05″ clearance above and below) can used for a 1-U package. In either example, a few thousandths of an inch of clearance room must be vacated to enable ease of installation.  
           [0009]    A piece of electronics equipment that is mounted in a chassis may vertically span more than one EIA unit of height. For example, a power supply module could be mounted into an EIA rack system and allotted a vertical space equivalent to 4 Us (1.75″×4=7″). If the manufacturer desires a minimum vertical clearance allowance (top and bottom) of 0.100 inches for example, the power supply could then be constructed to be 6.800 inches [(7.000−(2×0.010)] in height without concern for interfering with the installation or operation of adjacent pieces of equipment.  
           [0010]    Of course, it is always desirable to make electronic equipment smaller. Smaller electronic equipment means that more pieces of equipment can be housed in a rack. Unfortunately, as the desire for miniaturization of electronics devices progresses, the standard minimum vertical amount of rack space, 1-U, has remained substantially unchanged. Since the U represents a minimum height, a piece of equipment that has a height that is less than 1.75″ must still be mounted so as to take up a full U of height. To compensate for the required height, compact equipment often will not extend to the full depth (15″ vs. 30″, for example) of the rack. When components that do not extend the full depth are mounted in a standard rack, space can be wasted and an important benefit of the rack mounting of components is diminished. While it would be possible to design a new rack system with a new set of standards for equipment size, it is preferable to create a means to modify the storage capabilities of current EIA racks to allow more storage configurations to be achievable within the confines of a standard “legacy” rack. Many companies have already invested significant amounts of money on their current facilities and equipment and would prefer not to have to change their equipment. Furthermore, it is not entirely practical to arrange systems to less than a full EIA unit of height as devices that are often accessed at the front of a rack-mounted package (e.g., disk drives) require more height than such an arrangement would allow.  
           [0011]    In an attempt to conserve rack space, some have mounted two half-depth, 1-U systems in a rack, one from the front and another from the back of a 1-U space, in a “back-to-back” configuration with limited success. Although this method allows two devices to be secured within a single space, much of the functionality and benefit of the rack design is lost. For instance, because the systems are mounted “back-to-back,” the cabling that is required to power and communicate with the equipment located toward the back of the rack is now located in the center of the rack, in a location generally inaccessible without removing at least one electronic package. Further, these cables must be redirected either through a side or the middle of the rack in a manner that is completely unserviceable to a system administrator without disabling some of the affected components.  
           [0012]    Because EIA racks are so widely deployed and already represent a highly efficient means to package and store electronic components, a method to store more equipment within the confines of an existing EIA rack is highly desirable. Currently, there is no known way to conveniently house two, three, or more distinct electronic packages within a 1-U EIA rackspace from the front and trends in server appliance miniaturization and redundancy are increasingly demanding such a feature. The ease of installation, removal, replacement, and interchangeability would be greatly improved with a system that could efficiently pack such equipment.  
         BRIEF SUMMARY OF THE INVENTION  
         [0013]    The present invention overcomes the deficiencies of the prior art by providing a system to mount several servers within a 1-U space of a standard EIA electronics rack. The system includes mounting tray, or chassis, that is securely fastened to a standard 19″ EIA electronics rack. The tray includes dividers that define at least two full length ports per EIA unit into which electronic packages are slidably engaged. Furthermore, each port defined by the mounting tray includes hot-pluggable blind-mate sockets to receive corresponding hot-pluggable blind-mate connectors upon each electronics package. These packages are engaged and disengaged to and from the ports within the rack at will, thus allowing for more servers to be efficiently and accessibly stored within the confines of a 1-U rackspace than was previously possible. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:  
         [0015]    [0015]FIG. 1 a perspective view drawing of an interchangeable server mount system in accordance with a preferred embodiment of the present invention;  
         [0016]    [0016]FIG. 2 is a perspective view drawing of an electronic package in accordance with a preferred embodiment of the present invention that is to be contained within the server mount system of FIG. 1; and  
         [0017]    [0017]FIG. 3 is a rear view perspective view drawing of the electronic package of FIG. 2. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    Referring now to FIG. 1, an interchangeable electronics rack mount system  100  is shown. Interchangeable rack mount system includes a mounting chassis  102  positioned preferably within a 1 U rackspace of a standard 19″ EIA rack assembly  104 . Mounting chassis  102  preferably spans the width of the rack assembly  104 . A standard 1 U space of EIA standard 19″ rack  104  is 1.75 of height, 17¾ inches of usable width, and a varying degree of depth (preferably 30 inches). Mounting chassis  102  is positioned horizontally within rack  104  and secured in place by captive thumbscrews  106 . Rack  104  includes a plurality of vertically spaced mounting apertures  108  that receive screws  106 .  
         [0019]    Mounting chassis  102  preferably includes a bottom  110 , a left and right side  112 ,  114 , and a rear wall  116 . At least one divider  118  is mounted to the chassis bottom  110  and runs from the front of chassis  102  to the rear wall  116 . The divider  118  divides the chassis into multiple docking parts  120 . One divider  118  results in two docking parts. Two dividers create three docketing parts, and so on. Divider  118  is positioned substantially parallel to sides  112  and  114 . By placing dividers  118  at various positions within chassis  102  parallel to sides  112 ,  114 , different sized docking ports  120  can be created. Although it is preferable for each chassis  102  to contain  2  or  3  equally sized docking ports  120 , it should be understood that the relative size and number of ports  120  within chassis  102  can be any number desired. Preferably, located within the front left side of each port  120 , is a latch recess  128 . Recess  128  can take the form of a simple cutout in a divider  118  or in the left or right side  112 ,  114  of chassis  102 . At the rear of each port  120  of chassis  102  is a docking bulkhead  122  that receives power and data connections of a piece of equipment inserted into docking port  120 . Referring still to FIG. 1, bulkhead  122  preferably includes sockets that mate with corresponding blind-mate connectors on the piece of equipment in docking port  120 . Although a variety of sockets can be used, preferably at least one power socket  124  and at least one communications socket  126  are included in the docking bulkhead  122 .  
         [0020]    Referring now to FIG. 2, an electronics package  150  is shown disposed within a docking port  120 . The electronics package can be any type of digital or analog device such as a server, a storage system, or a power supply. Electronics package  150  is preferably constructed with a  152  and a front panel  154 . Front panel  154  preferably includes a handle  156  and a latch  158  for securing package  150  in position within mounting chassis  102 . Although not shown in FIG. 2, front panel  154  can include accessible floppy and CD-ROM drives to allow a user to upload and download data and configuration settings to a computing device contained within package  150 .  
         [0021]    Referring now to FIG. 3, the rear surface of electronics package  150  is shown as having a rear panel  160  with power and communications hot-pluggable blind mate connections  162  and  164  which mate with the power and communications sockets  124 ,  126  of bulkhead  122  of FIG. 1. As blind mating hot-pluggable connectors, connectors  162 ,  164  automatically connect to corresponding bulkhead sockets  124 ,  126  when the electronics package  150  is fully inserted into dockingport  120 .  
         [0022]    Referring to FIGS.  1 - 3  together, electronics rack mount system  100  is installed by first installing chassis  102  into rack  104  and securing with thumbscrews  106 . Chassis  102  is constructed to fit within the limitations of 1-U of EIA rackspace and multiple chassis  102  can be installed within vertically adjacent rack spaces together to form an array of ports  120 . For example, five chassises  102 , each with 3 ports  120 , could be stacked on top of each other in a rack to form an array of 15 docking ports  120 . Alternatively, a single chassis can be constructed to span vertically across more than one EIA unit and thus hold an array of ports  120 . For example, the 15-port array mentioned above could be created by installing a single 5-U chassis with each “U” containing 3 docking ports  120 . A potential advantage of such an arrangement could include the ability to share a common power or data distribution system across the entire array. For example, one power cable could be used to supply power to each of the power sockets in the array, thus eliminating a significant amount of cable clutter at the rear of rack  104 .  
         [0023]    Once chassis  102  is secured within rack  104 , connections at the rear of rack  104  are made to connect the sockets of each port  120  to power and communications cables. With the chassis  102  installed and connected, the server mount system  100  is ready for operation. Electronics packages  150  are slidably engaged into ports  120  created by dividers  118  and side rails  112 ,  114 . Packages  150  are slid into the ports  120  until they contact against rear wall  116  of chassis. As electronics packages  150  contact against rear wall  116 , blind-mate hot-pluggable connectors  162 ,  164  of rear panel  160  mate with bulkhead socket connectors  124 ,  126 . Power socket  126  of bulkhead  122  mates with power receptacle  162  of package  150  and communications socket  124  mates with connector  164 . When fully engaged into a port  120 , spring-loaded latch  158  of electronics package  150  engages recess  128  within chassis  102 , thus preventing removal of packages from server mount system  100 . When removal of package  150  is desired, the user slides latch  158  away from recess  128  and can then remove package  150  by grasping handle  156  and pulling package  150  away from port  120 . Furthermore, a latch activated electronic sensor (not shown) may be included within latches  158  to notify a system to prepare itself for its removal from a port  120 .  
         [0024]    Electronics mount system  100  offers the user the ability to replace servers, or any other electronic device, quickly and with little effort. Furthermore, the electronics mount system  100  of the present invention represents a dramatic improvement to the device capacity of a standard EIA rack. With conventional designs, it was only practical to store one component within a 1-U unit of rackspace. Alternative methods for housing several components within a single rackspace eliminated much of the functionality and convenience that is associated with the EIA rack mount design. A system in accordance with the preferred embodiment of the present invention allows the installation of multiple, full length packages within a single standard 1-U rackspace. By increasing the number of packages (from 1 per EIA unit to 2 or 3) rack users that require a high number of or any other rack mounted components, can store them more efficiently. This more efficient use of the storage space within an EIA rack allows businesses to expand their computing power and customer base without need for more office space.  
         [0025]    In deploying a system in accordance with the preferred embodiment of the present invention, EIA Rack users can store multiple appliances within a single rack space without departing from the features and spirit of the EIA rack mount concept. Such features include, but are not limited to, ease of installation into and removal from the rack, front panel access and input to the system, and connection access to the rear of the system.  
         [0026]    While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.