Heat exchanger
One of the features of this invention is to provide an improved heat exchanger comprising a plurality of spaced tubes for a first heat exchange fluid and fins attached by metallurgical bonds to the outer surfaces of the tubes and extending toward adjacent fins but spaced therefrom to provide substantially free flow of a second fluid over and between the fins. 
     The most pertinent prior art of which applicant is aware are U.S. Pat. Nos. 1,521,880; 1,646,384; 1,893,270; 1,910,486; 2,012,269 and 3,537,516. None of these, however, disclose the invention disclosed and claimed herein. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a fragmentary vertical sectional view through a tube and fin heat exchanger embodying the invention. 
     FIG. 2 is a fragmentary perspective view of a section of tube and an undulating fin metallurgically attached to an outer surface of the tube according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the illustrated embodiment the heat exchanger 10 comprises an upper tank 11 and a lower tank 12 spaced therefrom with the tanks being interconnected by spaced parallel tubes 13 for flow of a first heat exchange fluid such as water or other liquid coolant between the tanks 11 and 12, and through the tubes 13. 
     The tubes 13 as illustrated in FIG. 2 are of generally oval cross section with edge seams 14 that may be brazed, soldered, welded or the like. Each tube has spaced substantially parallel sides 15 providing outer surfaces 16. Attached to these outer surfaces 16 by a metallurgical bond, which may be by brazing, soldering or the like for better heat transfer, are fins 18 in sets 19 with adjacent sets spaced from each other at adjacent portions to permit flow of a second heat exchange fluid 22 such as air over the surfaces of the fins 18 between the fins in substantially unrestricted flow, therefore improving the heat transfer. 
     In the embodiment illustrated the fins 18 are essentially continuously V-shaped in cross section with the fins of the two sets each having a plurality of linearly successive apexes 23 adjacent to but spaced from corresponding apexes of the other set to provide spaces 24 for the second fluid 22 circulation. 
     The metallurgical bond 17 uniting the fins 18 to the tubes 13 not only provides a strong structure but also aids the heat transfer between the tubes 13 and the fins 18 and thereby between the fins 18 and the second heat exchange fluid 22. 
     The second fluid, or air, 22 is forced over and between the sets 19 of fins 18 as by a blower illustrated schematically at 25 in FIG. 2. This forced fluid (air) flow means 25 thereby drives the second fluid 22 through the spaces 24. Because of the narrow space 24 the back pressure on the flowing fluid (air) 22 forces more intimate contact between the fluid 22 and the surfaces 26 of the fins, thereby improving heat transfer with the fluid 22. 
     Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather by construed broadly within its spirit and scope as set out in the appended claims.