Safety Feature To Prevent Thermal Misuse In A Network Computer
Original Publication Date: 2000-Oct-01
Included in the Prior Art Database: 2003-Jun-18
This invention addresses the problem of system overheating in the event that the system support base is not attached to the system, by creating a method of preventing blockage of convective cooling air flow into the system chassis. In many small computers, buoyancy induced air convection is the means used to cool the system. In such applications, air flow both into and exiting the computer must remain unobstructed to prevent the system from overheating. This is especially important in small computers where the amount and size of air vents is limited. Entry air venting is most efficient when it is located at the very bottom of the system. However, if the bottom of the system is flat in shape, the cool air entering the system can be blocked by the customer if the system is placed on a flat surface (such as a desk) without the stand attached to the system. The system will operate, but it will eventually overheat, causing complete system failure. To prevent his scenario from occurring, this invention describes a claim that ensures proper system cooling by prohibiting the potential of misuse of the system. The system is externally comprised of a folded envelope of metal called the outer chassis cover. This cover has a series of openings in it for the purpose of air venting. The entry air venting is located at the extreme bottom of this external cover. To prevent this from being blocked when set upon a desk or work surface, the cover is formed such that an external longitudinal rib is created which prevents the system from standing upright when the base is not attached. The system is purposefully made to be vertically unstable such that it will tip over to one side if the stand is not present. On either lateral side of the rib is a series of air vents which remain unobscured and protected from being covered. The rib also provides an ideal place to weld the metal seam during the manufacturing process used to create it, and also creates an integral outer enclosure seal to preclude EMC emissions. Other NC's use plastic covers which have an integrally molded base. However, plastic covers with molded bases have the following disadvantages: 1) The shipping container packaging must be enlarged to accommodate the one piece shape, which correlates to increased shipping packaging cost. 2) Marketing feedback is that customers perceive the plastic covers to be cheap looking, and do not provide enough weight to act as an effective "anchor" for peripheral cables such as keyboard mouse cables. 3) EMC containment issues are a problem with plastic covers since metal provides a more effective (and environmentally friendly) EMC solution than plastic covers. And, lastly 4) in comparisons of similar sized metal enclosures, plastic metal hybrid covers are more costly to produce due to the redundancy of using metal liners or conductive plating/spray on plastic.