Abstract:
The present invention provides a mobile, electro-statically stable cart for storing and transporting computers, computer accessories, and sensitive computer equipment such as servers, Ethernet switches, and batteries. The body of the cart is configured to receive equipment in a portable rack mount fashion while providing protection against electro-static discharge events using anti-static wheels, either conductive or static dissipative, drag chains, grounding points, and static dissipative paint.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority from U.S. Provisional Application No. 60/580,247, entitled “Computer Rack Cart” filed Jun. 16, 2004, the entire disclosure and contents of which are hereby incorporated by reference. 

   BACKGROUND 
   1. Field of the Invention 
   The present invention is directed generally to a computer cart and, more specifically, to an electrostatically stable, mobile computer rack cart for rack mountable servers. 
   2. Related Art 
   Computers and other computer equipment are not only commonly used in businesses today but are often a key component to businesses. One of the biggest problems with computers and computer equipment is that it is heavy, bulky, but delicate in that they are vulnerable to electrostatic discharge events. Therefore, computers and computer equipment cannot be safely transported in an easy manner. So while it would often be more convenient to mobilize a computer and/or computer equipment, doing so is very risky because the likelihood of damaging the equipment by an electrostatic discharge event is high. 
   SUMMARY 
   According to a first broad aspect of the present invention, there is provided a mobile, electro-statically stable cart for storing and transporting computers rack mountable servers, computer accessories, and other sensitive computer equipment such as servers, Ethernet switches, and batteries. The body of the cart is configured to receive equipment in a portable rack mount fashion while providing protection against electro-static discharge events using anti-static wheels, either conductive or static dissipative, drag chains, grounding points, and static dissipative paint. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in conjunction with the accompanying drawings, in which: 
       FIG. 1  is a schematic view of a cart embodiment showing interior details and having a suspending support platform. 
       FIG. 2  is a schematic view of a cart embodiment showing exterior details and having a top panel support. 
       FIG. 3  is a side view of a cart with side panels removed showing interior equipment mounted details and electrostatic stability features. 
       FIG. 4  is a perspective view showing side panels separated from the cart, but connected by grounding wires. 
   

   DETAILED DESCRIPTION 
   It is advantageous to define several terms before describing the invention. It should be appreciated that the following definitions are used throughout this application. 
   Definitions 
   Where the definition of terms departs from the commonly used meaning of the term, applicant intends to utilize the definitions provided below, unless specifically indicated. 
   For the purposes of the present invention, the term “rack mount” refers to a cabinet for housing computers and computer equipment, wherein the cabinet is standardized by the Electronic Industries Alliance. 
   For the purposes of the present invention, the term “electrostatic discharge” refers to a phenomenon that occurs when two materials come together and then separate. At the time of separation, electrons are transferred from one material to the other; the material losing electrons is positively charged, and the material gaining electrons is negatively charged. 
   For the purposes of the present invention, the term “electrostatically stable” refers to a situation or environment in which an electrostatic discharge event will not occur. 
   For the purposes of the present invention, the term “conductive” refers to a having a high mobility of charge so that the potential on the surface is retained for only a very short time. 
   For the purposes of the present invention, the term “static-dissipative” refers allowing a charge to migrate over a surface in a time that is short compared to the time scale of the actions creating the charge or the time within which this charge will be effective or will cause an electrostatic problem. 
   For the purposes of the present invention, the term “grounding” refers to having uniform electrical potential established in an area ensuring uniformity of electrical potential of all objects. 
   For the purposes of the present invention, the term “computer equipment” refers to any equipment of, relating to, compatible with, or accessory to computers including but not limited to computers, servers, Ethernet switches, and batteries. 
   For the purposes of the present invention, the term “computer accessories” refers to any suitable accessory to a computer including but not limited to keyboards, mice, and speakers. 
   DESCRIPTION 
   The present invention is directed to a mobile, electro-statically stable cart for storing and transporting computer equipment in a rack mount configuration. The cart of the present invention allows computer equipment such as servers that are typically rack mounted in a stationary position to be safely mounted in a mobile configuration. One embodiment of the cart is shown in  FIG. 1 . As shown in  FIG. 1 , cart  100  includes a base  101  having an upper surface and a lower surface and a front side and back side. Wheels  102  are attached to the lower surface of base  101 . Base  101  preferably has four corners and a wheel  102  attached proximal to each of said corners; however, base  101  could be any desired and functionally feasible shape and any desired number of wheels could be attached to the base. 
   Wheels  102  are anti-static, being either conductive or static dissipative so as to promote grounding. The wheels can be conductive as for example, model 5MC Metro Conductive Stem Casters sold by InterMetro Industries Corporation, North Washington Street, Wilkes-Barrie, Pa. 18705. The casters conform to Federal Specification FF-C-88 C. 
   Support rails  103  are attached to the upper surface of base  101  and extend vertically to top panel  105 . There are at least four and preferably six support rails attached to base  101  including two front rails, two middle rails, and two rear rails. Each rail includes as series of holes  104  which serve as an attachment mechanism for computer equipment including but not limited to servers, batteries, and Ethernet switches, that can be attached directly to the support rails  103 .  FIG. 2  illustrates a cart  200  wherein computer equipment  214  is directly attached to cart  200  at holes  204  within rails  203 . In order to provide proper support of the equipment, it is critical that the rails  203  and the holes  204  within are aligned with one another. The computer equipment  214  is attached at the two front rails and extends back toward the middle and back rails, which provide support as needed. Further equipment can be attached to the middle and back rails. 
   Rear panel  106  extends from the base  101  to the top panel  105  to enclose the backside of the cart  100 . Rear panel  106  preferably includes vents  107  to allow for ventilation of the stored equipment and at least one access hole  113  to allow passage of equipment cords and data links and/or provide immediate access to equipment located in the back of the cart. Further rear panel  106  is removable to provide further access to equipment and wires in the rear of the cart  100 . As shown in  FIG. 2 , cart  200  further comprises side panels  206  to enclose the space between support rails  203 . Side panels  206  are preferably vented so as to allow for ventilation of stored equipment. This is preferably accomplished through the use of mesh  215  in the side panels  206 , but can also be accomplished by incorporating vents into side panels  206  such as vents  107  shown in rear panel  106 . Mesh  215  provides maximum ventilation while still providing some protection to the equipment  214  stored within the cart. 
   A top panel  105 , parallel to the base  101 , sits atop and is attached to the support rails  103 . Top panel  105  indirectly supports computer accessories such as a keyboard  110  or monitor  111  as shown in  FIG. 1 , or, alternately, top panel  205  directly supports computer accessories such as keyboard  210  and monitor  211  as shown in  FIG. 2 . For indirect support as in  FIG. 1 , an equipment platform  108  directly supports the keyboard  110  and monitor  111  while be suspended above and attached to top panel  105  by platform support  109 . Equipment platform  108  preferably includes handles  112  extending from both the front and rear of the platform. Having equipment platform  108  suspended above top panel  105  provides for additional space to transport further equipment, documents, etc. For direct support as in  FIG. 2 , the computer accessories rest directly on the top panel  205  while a handle  212  protrudes directly from the top panel  205 . As shown in  FIG. 2 , other computer accessories such as a mouse support  213  can be included on the top of the cart. Top panel  105  or  205  can also include at least one hole  216  for passage of cords, cables, etc. 
   In order to ensure electrical stability of the cart and thereby prevent electro-static discharge (ESD) events, the cart includes several anti-static measures as shown in  FIG. 3 . As discussed above, wheels  302  are anti-static, either conductive or static dissipative, to promote grounding of the cart. To further promote grounding, a drag chain  315  is suspended from cart  300  to contact the floor. Drag chain  315  is preferably made of brass and is suspended from base  301 . Cart  300  is also equipped with at least one, and preferably four, wrist strap grounding points  317  preferably located at top panel  305 . Wrist straps connected to the wrist strap grounding points  317  attach to the user(s) of the cart thereby keeping the user(s) at the same electrical potential as the cart to avoid and ESD event. Further, all side and rear cart access panels have ground points which are connected to the cart  300  at all times. Even when the panels are removed from the cart, they are connected by a wire to the cart as shown in  FIG. 4 . The wire  400  and  402  provide a grounded connection between the cart and the panels. Finally, the cart is preferably painted with static dissipative paint. Further safety features can be added to the cart such as a seismic tie down point  318  attached to base  301  or a static dissipative mat placed under the cart or on a portion of the cart such as the base or the top panel. Static dissipative mats are preferably made of either rubber or vinyl and have characteristics similar to static dissipative paint by controlling the rate of electrical discharge. When a mat is used under the cart, the mat is connected to a ground point through the use of a ground lead kit. 
   The cart of the present invention preferably has about the same width dimensions as an industry standard 19-inch computer rack mount. Therefore, computer servers and other equipment for which the industry standard racks are designed can fit within the cart, thereby making them mobile. Specifically, the width of the cart from the inside edge of one front, middle, or rear support rail to the inside edge of the adjacent front, middle, or rear support rail is at least about 17 inches, preferably about 17¾ inches; the width of the cart from the holes on one front, middle, or rear support rail to the holes on the adjacent front, middle, or rear support rail is at least about 18 inches, preferably about 18 5/16 inches; and the width of the cart from the outside edge of one front, middle, or rear support rail to the outside edge of the adjacent front, middle, or rear support rail is at least about 20 inches, preferably about 20 7/16 inches. 
   While the 19 inch rack dimensions are preferred, the cart could also have other width dimensions as desired such as the width dimensions of an industry standard 23 inch rack, i.e. the width of the cart from the inside edge of one front, middle, or rear support rail to the inside edge of the adjacent front, middle, or rear support rail is at least about 21 inches, preferably about 21¾ inches; the width of the cart from the holes on one front, middle, or rear support rail to the holes on the adjacent front, middle, or rear support rail is at least about 22 inches, preferably about 22 5/16 inches; and the width of the cart from the outside edge of one front, middle, or rear support rail to the outside edge of the adjacent front, middle, or rear support rail is at least about 24 inches, preferably about 24 7/16 inches. 
   Regardless of the width of cart, the depth of the cart from the front of the base to the rear of the base is at least about 30 inches, and preferably about 32 inches. While the height of the cart can vary, the preferred heights are 10 U or 14 U. 1 U equal about 1.75 inches; therefore, the 10 U cart yields about 17.5 inches in usable rack height from base to top panel while the 14 U cart yields about 24.5 inches in usable rack height from base to top panel. 
   All documents, patents, journal articles and other materials cited in the present application are hereby incorporated by reference. 
   Although the present invention has been fully described in conjunction with several embodiments thereof with reference to the accompanying drawings, it is to be understood that various changes and modifications may be apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom.