Abstract: A fin characterized by a corrugated shape and configured to be interposed between adjacent instances of tubes of a heat exchanger assembly includes a plurality of planar portions, a radiused portion, and a retention feature. The plurality of planar portions is configured to extend between the adjacent instances of the tubes. The radiused portion is located between adjacent planar portions and is configured to be in thermal contact with a tube proximate thereto. The retention feature is located substantially mid-way between a leading edge and a trailing edge of the fin. The retention feature is configured to contact the tube in a manner effective to prevent fall-out of the fin prior to brazing of the heat exchanger assembly.

Abstract: A fin characterized by a corrugated shape and configured to be interposed between adjacent instances of tubes of a heat exchanger assembly includes a plurality of planar portions, a radiused portion, and a retention feature. The plurality of planar portions is configured to extend between the adjacent instances of the tubes. The radiused portion is located between adjacent planar portions and is configured to be in thermal contact with a tube proximate thereto. The retention feature is located substantially mid-way between a leading edge and a trailing edge of the fin. The retention feature is configured to contact the tube in a manner effective to prevent fall-out of the fin prior to brazing of the heat exchanger assembly.

Abstract: A machine for making corrugated fins or air centers for heat exchangers from strip stock has forming rolls, packing rolls, metering rolls and two pairs of pullout rolls, each pair having a different number of teeth to produce a different pitch of convolutions. The pairs of pullout rolls are mounted for movement apart or together under control of a cam mechanism so that one pair yielding the desired pitch can engage the centers to set the pitch while the other pair is moved apart to disengage the centers.

Abstract: A flat tube and fin heat exchanger comprises a plurality of tubes arranged in spaced parallelism and a plurality of louvered fins are located between each of the tubes in heat exchange relationship with the tubes. The fins are formed as a series of sinusoidal corrugations defining axial air flow passages in a direction generally transverse to the longitudinal axes of the tubes. A predetermined series of fin panels have louvers formed therein to create turbulence in the axial air flow through the fins. A second series of fin panels are dammed to channel air flow through the tubes so as to maximize heat transfer characteristics of the heat exchanger.