Heat dissipation device for and method of dissipating heat from a manifold

1. An injection molding apparatus comprising:

a hot runner manifold;

a heater coupled to said manifold; and

a heat dissipation device, having a first end coupled to said manifold between said manifold and a cooler member, said cooler member having a lower temperature than said manifold;

wherein said heat dissipation device thermally expands and contacts said cooler member when a temperature of said manifold at said pre-determined location increases above a predetermined temperature.

2. The injection molding apparatus as claimed in claim 1 , wherein said heat dissipation device comprises a plurality of fins extending from a base.

3. The injection molding apparatus as claimed in claim 1 , wherein said heat dissipation device has a second end, said second end being bent towards said cooler member prior to the introduction of heat into said manifold.

4. The injection molding apparatus as claimed in claim 3 , wherein said heat dissipation device includes only a single layer of material.

5. The injection molding apparatus as claimed in claim 4 , wherein said single layer is selected from the group consisting of copper, copper alloys, aluminum, and aluminum alloys.

6. The injection molding apparatus as claimed in claim 1 , wherein said heat dissipation device includes a first layer that is directed toward a surface of said manifold and an opposed second layer.

7. The injection molding apparatus as claimed in claim 6 , wherein said first layer is more thermally conductive than said opposed second layer.

8. The injection molding apparatus as claimed in claim 7 , wherein said first layer is selected from the group consisting of copper, copper alloys, aluminum, and aluminum alloys.

9. The injection molding apparatus as claimed in claim 7 , wherein said second layer is selected from the group consisting of titanium, titanium alloys, stainless steels, iron alloys, ceramic and fiberglass.

10. The injection molding apparatus as claimed in claim 6 , wherein said first layer and said second layer are metallic.

11. The injection molding apparatus as claimed in claim 6 , wherein said heat dissipation device includes a third layer adjacent to said second layer and opposite said second layer from said first layer.

12. The injection molding apparatus as claimed in claim 11 , wherein said first and third layers are materials having a higher coefficient of thermal expansion than said second layer.

13. The injection molding apparatus as claimed in claim 1 , wherein said cooler member is a manifold backing plate.

14. The injection molding apparatus as claimed in claim 1 , further comprising a plurality of heat dissipation devices having a first end coupled to said manifold.

15. An injection molding apparatus, comprising:

a manifold;

a heater coupled to said manifold; and

a heat dissipation device coupled to said manifold, said heat dissipation device having a first spacial orientation when said manifold has a temperature below a predetermined temperature and a second spacial orientation when said manifold has a temperature greater than a predetermined temperature, wherein said first and second orientations differ in that said second orientation contacts an adjacent cooler member.

16. The injection molding apparatus as claimed in claim 15 , wherein said heat dissipation device is bent toward said cooler member prior to introducing heat to said manifold.

17. The injection molding apparatus as claimed in claim 15 , wherein said cooler member is a manifold backing plate.

18. The injection molding apparatus as claimed in claim 15 , wherein said heat dissipation device comprises a first layer and a second layer, wherein said first layer is closer to said manifold than said second layer and said first layer is a material having a greater coefficient of thermal expansion than said second layer.

19. An injection molding apparatus as claimed in claim 15 , wherein said heat dissipation device includes a plurality of fin portions extending from a band portion.

20. A method of locally cooling a manifold of an injection molding apparatus comprising:

measuring the temperature of said manifold;

identifying high temperature locations on a surface of said manifold;

coupling a first end of a heat dissipation device to said surface of said manifold at said high temperature locations;

positioning a second end of said heat dissipation device such that thermal expansion causes said second end to come into contact with a cooler member when the temperature of said surface at said high temperature locations increases to a predetermined temperature; and

heating said manifold surface to a temperature greater than said predetermined temperature.

21. The method of claim 20 , further comprising bending said second end away from said manifold surface and towards said cooler member.

22. The method of claim 20 , wherein said cooler member is a manifold backing plate.

23. A heat dissipation device for use with a hot runner manifold apparatus, comprising:

a first end thermally coupled with a hot runner manifold, a second end and one or more thermally conductive layers,

wherein said second end of said heat dissipation device thermally expands and contacts a cooler portion of said manifold apparatus only at temperatures above a predetermined temperature.

24. A heat dissipation device as claimed in claim 23 , wherein said second end of said heat dissipation device is bent away from said manifold.

25. A heat dissipation device as claimed in claim 23 , further comprising a first layer directed towards an outer surface of said manifold and a second layer adjacent to said first layer, wherein said first layer has a greater coefficient of thermal expansion than said second layer.

26. A heat dissipation device as claimed in claim 25 , further comprising a third layer adjacent said second layer and opposite said second layer from said first layer, wherein said third layer has a greater coefficient of thermal expansion than said second layer.

27. A method of dissipating heat from a manifold of an injection molding apparatus, comprising:

providing an injection molding apparatus including a manifold;

providing a manifold backing plate adjacent but not contacting said manifold;

providing at least one heat dissipation device having a first end and a second end;

coupling said first end to said manifold;

directing heat away from said manifold by allowing said heat dissipation device to thermally expand and contact said manifold backing plate when said manifold temperature increases beyond a predetermined temperature.

28. A method of dissipating heat from a manifold as claimed in claim 27 , further comprising bending said heat dissipation device away from said manifold and towards said manifold backing plate.

29. A method of dissipating heat from a manifold as claimed in claim 27 , wherein said heat dissipation device comprises a first layer directed towards an outer surface of said manifold and a second layer adjacent to said first layer, said first layer having a greater coefficient of thermal expansion than said second layer.