Browse Prior Art Database

Hot Swap Fan with Impeller Auto-Stop Feature Disclosure Number: IPCOM000030642D
Original Publication Date: 2004-Aug-20
Included in the Prior Art Database: 2004-Aug-20
Document File: 3 page(s) / 130K

Publishing Venue



Cooling of central processing units, chipsets, and other heat-generating devices has created a large challenge as we try to design densely packaged servers and workstations. Fans are used to push air over hot components and extract the heat from the systems. Due to the dense packaging of the systems, fans are often unable to provide nearly the maximum airflow that they are capable of since they are fighting so many impedences. Every time air flows through tight spaces (ie. between heatsink fins, memory DIMMs, etc) the airflow experiences a pressure drop. One significant source of pressure drops are the fan finger guards used to prevent customers and service technicians from cutting their fingers on spinning impellers. These finger guards are often needed on the sides of fans that are not even readily accessible while they are operating. Finger guards are required on these "burried" faces of fans since it is possible that fingers could interfere with the impellers of these hot-swappable fans as the fans are being removed from their power connectors but before the impellers have stopped spinning. Mechanisms for guarding fingers from the impellers of simple DC axial fans are heavily perforated plastic or sheetmetal panels or wire grills. If we could stop the fan impeller and elimate the need for a finger guard, then we could rid of this needless pressure drop.

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Hot Swap Fan with Impeller Auto -Stop Feature

    This invention is for a mechanical device that would interfere with the impeller and that slows or stops the impeller from spinning as the fan is being removed from a system, but before a person could get his or her fingers caught in the fan. This mechanical brake is to be part of the fan housing or part of the mechanism that the fan is mounted into. This invention eliminates the airflow impedence that is caused by finger guards.

    This invention eliminates the finger guards used on hot-swap fans that cause airflow impedence and lower the CFM output of a fan. This invention is for a mechanical device that interferes with the impeller as the fan is being lifted out of its port and slows or stops the spinning of the impeller and, hence, eliminates the possibility of finger damage. Therefore, this invention maintains the safety of people's finger, but does not decrease the fan's airflow output by adding the pressure drop of typical finger guards.

There are two possible implementations of this invention.

     One implementation is that of an arm or tab that touches either the front side or back side of the impeller as the fan is being lifted from its housing. A fan holder assembly is made that utilizes levers that will provide a force onto this arm as the fan is being pulled out of its connector.


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     The other implementation is for that of a leaf-spring-shaped device that is integrated into the fan housing. This device...