GB2201041A - Heat sink - Google Patents

Abstract

An extruded heat sink has at least one re-entrant slot (5-8) along its length and an extruded insert adapted to be slid into the slot and located therein. The insert may be a blanking piece adapted to receive a screw, or may itself have a re-entrant slot to receive a bolt head. <IMAGE>

Description

Heat Sink This invention relates to heat sinks and has particular reference to extruded heat sinks. It is well known to manufacture heat sinks for use in the cooling of electronic components. It is also well known to manufacture such heat sinks by extruding a metal, normally aluminium, through a complex shaped die to produce a heat sink section which is often referred to as a comb section.

By the present invention there is provided a kit of parts comprising an extruded heat sink having a re-entrant slot along its length and an extruded insert adapted to be slid into the slot and to locate therein.

The extruded heat sink may be a comb type heat sink with the slots on one or both ends of the comb.

The extruded insert may itself be provided with a re-entrant slot. The extruded insert may be solid or may be tubular and may have holes along its length. The holes may be threaded. The extruded insert may be so shaped as to form#a smooth face across the heat sink at the position of the re-entrant slot.

By way of example embodiments of the present invention will now be described with reference to the accompanying drawings, of which: Figure 1 is a cross-section of a comb type heat sink; Figure 2 is a partial cross-section of a re-entrant slot together with a re-entrant insert; Figure 3 is a partial cross-section of a re-entrant slot with a blanking insert; Figure 4 is a perspective view of one side of a heat sink incorporating an insert with in-built threaded holes; and Figure 5 is a side view of an insert as shown in Figure 4.

Figure 6 is a cross section of a blanking piece.

Figure 7 is a cross sectional view of a further form of kit, and Figure 8 is an end elevation of four extrusions connected together by corner pieces.

Referring to Figure 1 this shows an extruded heat sink which forms one part of the kit of parts. The extruded heat sink is manufactured of aluminium by a conventional extrusion process which involves forcing an aluminium billet through a nozzle or die of cross-section which is identical to that illustrated in Figure 1.

The heat sink illustrated in Figure 1 is a conventional comb type heat sink which has a series of comb members 1 integral with a base 2 and with a pair of upstanding end members 3 and 4. The end member 3 has an upper re-entrant slot 5 and a lower re-entrant slot 6. The end member 4 has a lower re-entrant slot 7 and an outer re-entrant slot 8. It will be appreciated that a re-entrant slot is one in which the mouth of the slot is narrower than the internal dimensions of the slot so that material can only be inserted, if it is larger than the dimensions of the mouth, by sliding the material in from one end.

The re-entrant slots are used to retain captive nuts which are used to mount the heat sink on suitable electronic apparatus.

The kit of parts may be completed by the provision of a second component as illustrated in Figure 2. In this illustration there is provided an extruded member 9 adapted to be mounted in the re-entrant slot 10. The extruded member has itself a re-entrant slot 11 and can be used to retain a bolt head for a captive bolt.

In an alternative form of second component used to manufacture the kit of parts there is provided a blanking piece 12 to blank the re-entrant hole 13 as shown in Figure 3. The blanking piece 12 can be solid or may be hollow as shown by dotted line 14.

The blanking piece 12 may be provided with holes as is illustrated in Figure 4. In this case a short blanking piece 15-provided with holes 16 is slid into re-entrant slot 17. The blanking piece is shown more clearly in Figure 5 and it can be seen that the blanking piece holes are unthreaded. However, if required the blanking piece holes could be threaded.

It will be appreciated that in those arrangements in which a blanking piece is provided which serves only to form a smooth exterior on the heat sink, the portion entering the hole can be of any desired shape and need not have the exact cross-section of the re-entrant hole itself.

The blanking piece may be provided with ribs 18 to accept a threaded bolt or screw without further threading, as shown in Figure 6.

Figure 7 shows two comb type heat sinks 20, 21 interconnected by an extrusion link 22.

Figure 8 shows four comb type heat sinks 23, 24, 25, 26 interconnected by identical corner pieces 27. The identical corner pieces are triangular in cross section and are in fact right-angled triangles so that the extrusions 23 to 26 form together a box.

Claims (9)

CLAIMS:

1. A kit of parts comprising an extruded heat sink having a re-entrant slot along its length and an extruded insert adapted to be slid into the slot and to locate therein.

2. A kit as claimed in Claim 1 in which the extruded heat sink is a comb type heat sink with slots, with the slots on one or both ends of the comb.

3. A kit as claimed in Claim 1 or 2 in which the extruded insert is itself provided with a re-entrant slot.

4. A kit as claimed in any one of Claims 1 to 3 in which the extruded insert is solid or tubular, having holes along its length.

5. A kit as claimed in Claim 4 in which the holes are threaded.

6. A kit as claimed in any one of Claims 1 to 5 in which the extruded insert is so shaped as to form a smooth face across the heat sink at the position of the re-entrant slot.

7. A kit as claimed in any one of Claims 1 to 6 in which the extruded insert comprises a triangular corner piece adapted to interengage two extrusions so as to locate them at an angle.

8. A kit as claimed in Claim 7 in which the angle is a right-angle.

9. A kit of parts substantially as herein described with reference to and as illustrated by Figures 1 to 5 and Figures 6 and 7.