CPU heat dissipating device

Claim 1

A CPU heat dissipating device adapted to be mounted to a casing of a CPU having a surface on which slots are provided, the CPU heat dissipating device comprising: a base made of a material of high heat conductivity, having a bottom configured to be in snugly tight engagement with the casing surface for heat transfer purpose and a plurality of fins extending from the bottom in a direction to have free ends thereof away from the CPU, the fins being arranged to spaced from each other so as to define a plurality of passages extending in a first direction, the base having a channel extending in the first direction, the channel having a bottom defining a circular bore with a neck formed therebetween, the fins comprising two outermost ones, each having a sideways-extending flange; a fan supported on a support plate which is supported on the free ends of the fins, the support plate having two ribs extending therefrom to be respectively received within two corresponding ones of the passages, the support plate having two lateral side walls each having an inward flange to engage the sideways-extending flanges of the outermost fins for holding the fan on the fins; a crank shaft having a circular section received and extending along the circular bore to be rotatable therein about a central axis thereof, at least one transverse projection being provided on the circular section, the circular section having two ends located outside the bore of which one has a transverse extension thereon for manually rotating the circular section about its central axis between a disengaged position and an engaged position and a second one of the ends having a circumferential slot to receive therein a C ring for holding the crank shaft within the bore; and a spring plate having an elongated central plain strip received within the channel of the base, two pairs of lateral extensions extending on the plane of the plain strip laterally from two opposite edges of the strip in opposite directions to be received within cutouts formed through the fins in a second direction substantially normal to the first direction, each of the lateral extensions having an arm extending therefrom in a direction substantially normal to the plane of the strip to have a catch that is formed on free end thereof extending into a corresponding one of the slots formed on the CPU casing, the central strip being so received within the channel to be supported on the neck with the lateral extensions in contact engagement with and fixed by the ribs of the support plate of the fan so that when the crank shaft is rotated from the disengaged position to the engaged position, the at least one transverse projection of the circular section of the crank shaft is brought into contact engagement with the central strip of the spring plate, the transverse projection being sized so that the contact engagement thereof with the spring plate elastically deforms the spring plate in a direction away from the crank shaft with the lateral extensions fixed by the ribs of the support plate of the fan, which elastic deformation of the spring plate moves the catches of the arms relative to the slots of the CPU casing so as to have the catches engage the slots and thus securing the heat dissipating device on the CPU.