US 2820616 A
Description (OCR text may contain errors)
Jan 21, 1958 E. E. NABAL ETAL ,82
PRESSURIZED ELECTRONIC CASE Filed Sept. :5, 1952 FIG. I
INVENTOR. EMERSON E. NABAL BYWILLIAM J. STEINMETZ ttite PRESSURIZED ELECTRONIC CASE Emerson E. Nabal, Lawrence, and William J. Steinmetz, Indianapolis, Ind, assignors to the United States of America as represented by the Secretary of the Navy Application September 3, 1952, Serial No. 307,726
1 Claim. (Cl. 257-250) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.
The present invention relates to pressurized electronic cases and more particularly to a pressurized electronic case constructed to more efficiently dissipate the heat generated by the electronic equipment housed in said case.
In prior art devices of this type the pressurization of the case rendered the heat dissipation very inefiicient with the attendant rapid deterioration of the components housed within the case.
The present invention provides a case constructed to provide an inner pressurized section and an outer section open to the atmosphere with a heat exchange means between the sections.
it is an object of this invention to provide a pressurized case which facilitates the dissipation of any heat generated by components housed within it.
A second object of this invention is to provide a lightweight rectangular pressurized case for an electronic unit.
A third object of this invention is to utilize the advantages of corrugated sheet metal strengthened by band members to provide a lightweight trusswork construction.
A fourth object of this invention is to provide an electronic case construction having heat exchanging features.
A fifth object of this invention is to provide an electronic case construction that will dissipate the heat given off by an enclosed electronic unit.
A sixth object is to provide an easily manufactured pressurized case which has the required dimensional stability.
Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:
Fig. 1 shows an isometric view of the case with the end removed, illustrating the interior structure schematically.
Fig. 2 is a sectional view taken along a longitudinal axis of Fig. 1.
Fig. 3 is a modification of Fig. 2 wherein the outer shell is replaced by reinforcing bands.
Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Fig. 1 a case having an inner shell surrounded on four of its sides by an intermediate shell 11 which has channelized or corrugated side walls such that there are formed between the inner shell 10 and intermediate shell 11 spaced ducts extending parallel to the longitudinal axis of the sides of shells 10 and 11. The intermediate shell 11 is made from corrugated or reverse bended sheet metal and the peaks thereon are referred to as tops 27 and bottoms 29. The ducts 15 result from the contact between the bottoms 29 and the inner shell 16). These ducts provide 2,820,615 Patented Jan. 21, 1958 both reinforcement for the unit and also provide increased area for heat transfer between the intermediate shell 11 and the surrounding medium. The intermediate shell 11 extends beyond each end of inner shell 10 to allow access to these ducts 15 when the ends of intermediate shell 11 are closed by covers 12 which are constructed to conform to the configuration of the ends of intermediate shell 11, thereby forming a case. Such an interfitting shell arrangement lends itself to simple manufacturing procedures while producing an article which is highly eificient for its intended use. Inner shell 10 of the case is divided into two compartments 25 and 26 by a partition 14 which has a motor driven fan 16 mounted in an aperture 17 in the partition 14. Surrounding intermediate shell 11 at spaced intervals there may be placed reinforcing bands 18, see Fig. 3, to assist in preventing deformation of the case when pressure is established within. The above construction characterizes the basic concept of the invention, but where greater heat dissipation is required an outer shell 19 may be constructed to enclose the first two shells 10 and 11 fitting in engaging contact With the tops 27 of the channels or corrugations 28 in intermediate shell 11 thus forming ducts 21 between the sides of shells 11 and 19. Outer shell 19 preferably extends beyond one end of intermediate shell 11 and has an end member 22 having an aperture 23 with a motor driven fan 24 mounted therein. It is noted that in reference to closures 12 when it is used with the outer shell 19 it closes only those ducts 15 which lie between shells 10 and 11 and that it is closure 12 which maintains the pressure in shells 10 and 11, when the case is pressurized.
In operation, the heat generated by an electronic component mounted within the inner shell 10 is transferred by conduction to the surrounding gaseous fluid and by conduction and radiation to the walls of inner shell 10 and through inner shell 10 to the walls of intermediate shell 11. The fluid, when heated, also transfers heat to the walls of shells 10 and 11 by convection. This heat transfer through the fluid to the outer walls of intermediate shell 11 is accelerated by employing the fan 16 to create a forced draft which circulates the fluid over any heat generating surface in compartment 25 and then forces the heated fluid into ducts 15 by the baffle effect of one of the closures 12. The fluid then circulates through the ducts 15 to compartment 26 While transferring the heat load to the walls of ducts 15 in passing through said ducts 15 thus forming a closed circulating system within the pressurized case. The heat may then be removed from intermediate shell 11 either by radiation and normal convection or when outer shell 19 with fan 24 is employed the forced draft from fan 24 passes through ducts 21 and carries the heat transferred from the surface of intermediate shell 11 into the surrounding atmosphere through the open ends of ducts 21. Since the transfer of heat between surfaces is proportional to the area of contact, it follows that, by providing the channelized surface of intermediate shell 11, the area of contact between both the heated gaseous fluid within the case and the surrounding air is increased with an attendant increase in the effectiveness of heat dissipation from any heat producing electronic component housed within the case, as Well as the strengthening of the cases.
It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention.
What is claimed is:
A pressurized case for supporting electrical components comprising; a first open ended rectangular inner shell; a partition dividing said inner shell into two compartments, said partition having, an aperture therein; a'reca v ducting; contact With said inner shell and forming longitudinal. ducts between said inner and intermediate shells; hermetic closure means for the ends of said intermediate shell; a rectangular outer shell greater in length and-extending beyond one end of said intermediate shell and surrounding said intermediate shell and forming longi- .tudinal ducts between said outer shell and intermediate shell; an end member having an aperture therein for enclosing. the end of said outer shell extending beyond said intermediate shell; a fluid enclosed within said inner and intermediate shells; means mounted within said inner shell for circulating said fluid through said inner shell and 4 said ducts formed by said inner and intermediateshells; and circulating means mounted in said aperture of said end member for circulating air in said ducts formed by said intermediate and outer shells.
References Cited in the file of this patent UNITED STATES" PATENTS King May 12, 1931 1,804,624 2,273,244 Ambruster Feb. 17, 1942 2,362,044 Blancha Nov. 7, 1944 2,511,875 Protzeller: June 20, 1950 2,654,583 Treanor Oct. 6, 1953 I FOREIGN PATENTS 279,828 Great Britain Oct; 18, 1927