Abstract: A heat exchanger in the form of a heat radiating or absorbing panel is disclosed, which consists of an aluminum panel having a copper tube secured thereto in heat exchange relationship. The panel has at least one pair of parallel, spaced, retainer legs which have angularly inwardly extending flanges. A copper tube of circular cross section is laid into the channel formed by said retainer legs, and is then squashed by means of a die into a generally oval cross section which will be confined within the retainer legs. While so confined, fluid under pressure may be introduced into the tube to expand it into intimate contact with the panel, the retainer legs and the flanges. The assembly may then be heated during the expanding step to a temperature somewhat above the expected operating temperature of the assembly, to prevent loosening of the intimate contact between the tube and panel, which have different coefficient of expansion. Provision may be made to cause flow through the tube to be turbulent or swirling.

Abstract: There is disclosed an assembly comprising a piece of rigid sheet material and a rigid linear member of metal, plastic, wood or other material, secured to an edge of the sheet material. The linear member and sheet are held in positive and immovable engagement and at the same time the joint is completely sealed to prevent the passage of liquids or gases therethrough. The mechanical means employed to lock the linear and sheet members together positively is so arranged that its presence is evident only on one side of the linear member. The assembly is so constructed that it can be taken apart readily without destroying either the sheet or the linear member. It is specifically disclosed in connection with a removable hatch for automobile roofs.