Cooling electronic apparatus

Abstract

An electronic apparatus having a heat dissipative external enclosure is disclosed. The external enclosure having a containment wall from which depend extended surfaces or fins having a length extending vertically and defining channels therebetween. The thickness of the enclosure between external surfaces of opposed containment walls varying between a relatively thin portion and a relatively thick portion to provide an interior space having a relatively narrow portion and a relatively wide portion to accommodate components or units of corresponding different extent. The fins having outer edges, spaced from the containment wall, and having plain first opposed surfaces adjacent their outer edges, the first surfaces including a first angle therebetween. The fins or parts of fins adjacent the relatively thin portion of the enclosure also having plain second opposed surfaces inwards of the first surfaces, the second surfaces including therebetween a second angle greater than the first angle. Making the thickness of the enclosure between external surfaces of opposed containment walls vary between a relatively thin portion and a relatively thick portion so that the interior space fits components or units of corresponding different extent, allows the fins to have a greater depth than would be the case if the thickness were constant. Making the deeper fins with roots having a greater draft angle, e.g. 3.degree. allows the deeper fins or parts of fins to come out of the mould more readily than using a constant draft angle, e.g. 2.degree., especially when the casting material is LM20.

Dependencies are inferred from the claim text.