Electricity: electrical systems and devices – Housing or mounting assemblies with diverse electrical... – For electronic systems and devices
Reexamination Certificate
1999-12-10
2001-06-26
Picard, Leo P. (Department: 2835)
Electricity: electrical systems and devices
Housing or mounting assemblies with diverse electrical...
For electronic systems and devices
C361S690000, C361S692000, C174S015100, C174S016100, C174S016300, C454S184000
Reexamination Certificate
active
06252769
ABSTRACT:
This application claims priority under 35 U.S.C. §§119 and/or 365 to 9804299-7 filed in Sweden on Dec. 11, 1998; the entire content of which is hereby incorporated by reference.
TECHNICAL FIELD
The present invention relates to the field of devices for increasing the heat transfer from an object.
DESCRIPTION OF PRIOR ART
Technical equipment often comprises electronics (or other objects) which needs to be cooled, on one hand to prevent the electronics and other adjacent equipment from being overheated, on the other hand to prevent persons who come into contact with the technical equipment from getting burned.
One way of cooling the electronics is to arrange the electronics in a good thermal contact with a heat sink, which has a relatively large heat transferring surface from which heat is transferred to the surroundings (e.g. surrounding air). The heat sink is usually made of a material with relatively good thermal conductivity and usually comprises heat dissipators, such as cooling flanges or similar, to increase the heat transferring surface.
However, the heat sink usually requires a relatively large amount of space, which of course is a disadvantage for such technical equipment that cannot take a lot of room.
There are, however, ways to increase the heat transfer from the heat sink so that the size of the heat sink can be decreased.
One way to increase the heat transfer is to use fans or similar means to generate an air motion in the air surrounding the heat sink. However, the fans have a disadvantage in that they generate disturbing noise. The fans have another disadvantage in that they require maintenance, for example due to lubricant in the bearings of the fans getting old and therefore must be replaced at certain time intervals. The fans have a further disadvantage in that they take a relatively large amount of room.
Another way to increase the heat transfer from a heat sink is to use an infra-sonic generator to generate an air motion in the air surrounding the heat sink. In a report (Bengt Petersson, 1989, “Infraljuds inverkan p{dot over (a)} värmeöverg{dot over (a)}ngstalet”, R15:1989, Statens Byggforskningsrad, Stockholm, ISBN 91-540-4979-2), published by Svenska Statens Byggforskningsr{dot over (a)}d, it is shown that it is possible to achieve substantially as good efficiency, concerning increasing the heat transfer, using an infrasonic generator as using a fan. However, the infrasonic generator has a disadvantage in that it works effectively if the heat sink has dimensions that are similar or less than particle movements of the air motion that is generated by the infrasonic generator. The size of the particle movements is usually in the order of 1 cm and less. As the heat sinks usually need to be considerably larger, this way to increase the heat transfer has not come to a wide practical use.
PRESENTATION OF THE INVENTION
The present invention refers to the problem of providing a device for increasing the heat transfer from an object.
In short, the problem stated above is solved with a device, which comprises one or more oscillating membranes to generate an air motion in air surrounding the object. Further, the device comprises means for affecting the air motion so that this causes a continuous exchange of the air surrounding the object. From the continuous exchange of the surrounding air follows that the object all the time is surrounded by relatively cold air, and therefore the heat transfer from the object to the surrounding air is efficient.
An object of the invention is thus to provide a device for increasing the heat transfer from an object.
The problem stated above can be solved in more detail according to the following. The means to affect the air motion comprises one or more nozzles with flow resistances depending upon the direction of the flow. The nozzle (nozzles) causes a net flow of air through the nozzle, whereby the device is arranged to take advantage of the net flow of air, to obtain the continuous exchange of air surrounding the object. The object is, for example, a heat sink which, for example, is used for cooling electronics or something else. Another example is that the object comprises electronics or something else that is to be cooled.
The invention has, apart from solving the problem stated above, the advantage that the device is relatively quiet and therefore does not disturb the surroundings, especially if the membrane (membranes) is arranged to oscillate with a frequency in the infrasonic sound range. Further advantages are that the membrane (membranes) takes little room and comprises no parts, such as bearings or the like, requiring continuous maintenance.
The invention will now be described more closely with the aid of preferred embodiments and with reference to the attached drawings.
REFERENCES:
patent: 4063826 (1977-12-01), Riepe
patent: 4498851 (1985-02-01), Kolm et al.
patent: 4780062 (1988-10-01), Yamada et al.
patent: 4834619 (1989-05-01), Walton
patent: 4923000 (1990-05-01), Nelson
patent: 5104626 (1992-04-01), Yang
patent: 5522712 (1996-06-01), Winn
patent: 5914856 (1999-06-01), Morton et al.
patent: 6043978 (2000-03-01), Mody et al.
patent: 0 601 516A1 (1994-06-01), None
patent: 08330488 (1996-12-01), None
patent: 508 435 (1998-10-01), None
patent: 96/00849 (1996-01-01), None
patent: 98/54765 (1998-12-01), None
Petterson, “Infraljuds inverkan på värmeövergångstalet”, R15:, Statens Byggforskningsråd, Stockholm, ISBN 91-540-4979-2, 1989; (Comment: English summary in chapter 13).
Liljencrants, “Elektroakustik”, Stockholm, ISSN 0280-9850, pp. 5-16, 1993.
Bergman Patrik
Edgren Anders
Tullstedt Carl Henrik
Burns Doane Swecker & Mathis L.L.P.
Chervinsky Boris L.
Picard Leo P.
Telefonaktiebolaget LM Ericsson (publ)
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