Heat sink fastening device and thermal module assembly using same

摘要

A heat sink fastening device includes an operating member and a retaining member axially extended through the operating member and associated with the latter via a pivot shaft. The operating member includes a cylindrical cam portion, which has an elastic element received therein to provide the cam portion with an elastic force. The cam portion has an upper end formed into a pair of cam surfaces, on which the pivot shaft is rested. The operating member can be horizontally rotated about an axis thereof. When the operating member is rotated, the cam surfaces rotate and cause the pivot shaft to move from a higher to a lower position on the cam surfaces or vice versa, so that the retaining member associated with the operating member via the pivot shaft is brought by the pivot shaft to axially move downward to a released position or upward to a fastened position.

主权项

1. A heat sink fastening device, comprising:
an operating member including a cylindrical cam portion and a switch portion radially outward extended from an outer surface of the cam portion; the cam portion having an upper end and a lower end; the upper end being formed into a pair of cam surfaces, each of the cam surfaces having two opposite ends respectively formed with a high-point notch and a low-point notch; and the cam surfaces being respectively extended from the low-point notch to the high-point notch in an upward slope; a mounting ring being mounted in the cam portion and internally defining an axial bore; a retaining member being axially extended through the cam portion and having an upper end and a lower end; the upper end being provided with at least one pivot hole, and the lower end being downward extended to form a retaining portion, which is provided with at least one engaging hole; and the upper end of the retaining member being upward extended through the axial bore of the mounting ring to the upper end of the cam portion; an elastic element being received in the cam portion and located below the mounting ring to fit on around the lower end of the retaining member; and a pivot shaft being located on the upper end of the cam portion and rotatably received in the at least one pivot hole formed at the upper end of the retaining member; and the pivot shaft having a first end portion and a second end portion being separately rested on the pair of cam surfaces; and wherein the switch portion of the operating member can be horizontally pulled from one position to another position to rotate the cam portion about an axis thereof, so that the cam surfaces are brought to rotate at the same time, causing the first end portion and the second end portion of the pivot shaft to move along the cam surfaces from the high-point notches to the low-point notches or vice versa, which in turn brings the retaining member to move downward or upward in the direction of the axis of the cam portion.