Abstract: A fin array for a heat exchanger and method of forming same are disclosed. The fin array is an elongated one piece element that includes a plurality of fins. The fins include connected staggered top segments and bottom segments. A top bend axis extends continuously across a plurality of the top segments.

Abstract: A heat exchanger assembly of the side-entry type includes at least one fin set and an elongated heat exchanger tube having one or more collapsed sidewall portions extending substantially the length of the tube. The folded tube is first bent to form the return bend portions and then is expanded to engage the fin set. Methods of making the elongated heat exchanger tube having one or more collapsed sidewall portion methods of making heat exchanger assemblies are also disclosed.

Abstract: An improved fin array for use in a heat transfer assembly, such as a condenser for a vehicle air conditioning system, and a method of making the improved fin array, are disclosed. The fin array comprises an elongated one-piece fin member having top and bottom base portions with fin sets extending between adjacent top and bottom base portions. The top and bottom base portions are generally flat for bonding to the heat exchanger tubes, such as by brazing. Each fin set includes a plurality of individual fins extending perpendicularly to a longitudinal length of the fin member and having side edges that are longitudinally offset with respect to each other. The offset fin edges provide increased fresh air flow over the individual fins and thus increase the efficiency of the overall heat exchanger.

Abstract: A heat exchanger assembly of the side-entry type includes at least one fin set and an elongated heat exchanger tube having a collapsed sidewall extending substantially the length of the tube which permits the bending of the elongated heat exchanger tube at the return bend portions and permits expansion of the elongated tube to engage the fin set.

Abstract: An improved fin array for use in a heat transfer assembly, such as a condenser for a vehicle air conditioning system, and a method of making the improved fin array, are disclosed. The fin array comprises an elongated one-piece fin member having top and bottom base portions with fin sets extending between adjacent top and bottom base portions. The top and bottom base portions are generally flat for bonding to the heat exchanger tubes, such as by brazing. Each fin set includes a plurality of individual fins extending perpendicularly to a longitudinal length of the fin member and having side edges that are longitudinally offset with respect to each other. The offset fin edges provide increased fresh air flow over the individual fins and thus increase the efficiency of the overall heat exchanger.

Abstract: An improved fin array for use in a heat transfer assembly, such as a condenser for a vehicle air conditioning system, and a method of making the improved fin array, are disclosed. The fin array comprises an elongated one-piece fin member having top and bottom base portions with fin sets extending between adjacent top and bottom base portions. The top and bottom base portions are generally flat for bonding to the heat exchanger tubes, such as by brazing. Each fin set includes a plurality of individual fins extending generally perpendicularly to a longitudinal length of the fin member and having side edges that are longitudinally offset with respect to each other. The offset fin edges provide increased air flow over the individual fins and thus increase the efficiency of the overall heat exchanger. The fins may also be slightly bowed to accommodate for variation in the tolerances of the adjacent tubes.

Abstract: Methods of brazing and coating and preparing articles for brazing and coating are disclosed. Prior to assembly and brazing, the articles are coated with a coating composition including a hot melt adhesive medium and brazing materials. To coat the articles, the hot melt adhesive medium and brazing materials are first mixed at elevated temperatures to form a liquid coating material, the material is allowed to harden, and the hardened material is then melted onto the articles to form a hard coating. The coated articles are then assembled for brazing. During the brazing process, the articles are first preheated to a sufficient temperature to substantially gasify and remove the hot melt adhesive medium from the articles. This leaves only the brazing materials on the articles for clean and efficient brazing of the articles in a conventional brazing oven. In one embodiment, the hot melt adhesive medium takes the form of a hot melt glue from the chemical family of ethylene-vinyl acetate bases.

Abstract: Methods of brazing and coating and preparing articles for brazing and coating are disclosed. Prior to assembly and brazing, the articles are coated with a coating composition including a hot melt adhesive medium and brazing materials. To coat the articles, the hot melt adhesive medium and brazing materials are first mixed at elevated temperatures to form a liquid coating material, the material is allowed to harden, and the hardened material is then melted onto the articles to form a hard coating. The coated articles are then assembled for brazing. During the brazing process, the articles are first preheated to a sufficient temperature to substantially gasify and remove the hot melt adhesive medium from the articles. This leaves only the brazing materials on the articles for clean and efficient brazing of the articles in a conventional brazing oven. In one embodiment, the hot melt adhesive medium takes the form of a hot melt glue from the chemical family of ethylene-vinyl acetate bases.

Abstract: A heat exchanger assembly of the side-entry type includes at least one fin set and an elongated heat exchanger tube having a collapsed sidewall extending substantially the length of the tube which permits the bending of the elongated heat exchanger tube at the return bend portions and permits expansion of the elongated tube to engage the fin set. Method and apparatus for making the elongated heat exchanger tube having the collapsed sidewall substantially extending the length of the tube as well as methods of making heat exchanger assemblies.

Abstract: Microextruded tubes each having two side surfaces, front and trailing edge surfaces and two ends are provided for insertion into aligned slots in headers to complete a heat exchanger assembly. The tubes each include a first coating composition containing an adhesive binder vehicle, flux material and brazing alloy deposited on the side surfaces adjacent the ends of the tube. The first coating composition is structurally arranged and applied to engage the aligned slots in the headers upon the insertion of the ends of the tubes into the header. The side surfaces of the microextruded tube include a second surface coating containing an adhesive binder vehicle, flux material, zinc and silicon extending the length of side tube between the deposited first coatings. The front and trailing edge surfaces of the tube include a third surface coating composition containing adhesive binder vehicle, flux material and zinc. A method of manufacturing parallel flow-type heat exchangers is disclosed.

Abstract: A method and apparatus for forming a heat exchanger assembly including wrapping a one-piece heat exchanger tube onto a heat transfer unit having a plurality of fins on upper and lower surfaces, the fins being provided with notches which are aligned in sets with each set of notches receiving a section of the heat exchanger tube as it is wrapped around the heat transfer array, return bend portions of the heat exchanger tube being formed in the wrapping process to have a generally rectangular cross section to maximize the cross sectional area of the heat exchanger tube in the return bend areas of the tube. Apparatus for forming the heat exchanger assembly includes a mandrel for rotating the fin unit, drawing the heat exchanger tube around the fin unit, and forming devices mounted on the mandrel to define the pitch of the return bends and to maintain the cross section of the heat exchanger tube in the return bend portions generally rectangular in shape when the heat exchanger tube subsequently is expanded.

Abstract: A method for separating a thin-walled multiport extrusion into a plurality of micro-tubes for use as single pass lengths in a heat exchanger assembly, the method including the steps of threading the micro-extrusion into a clamping device including first and second sets of clamping blocks which hold the micro-extrusion rigidly while the clamping blocks of the clamping device are drawn in opposite directions on opposite sides of a groove cut in the upper and lower walls of the extrusion, tearing the extrusion apart along cutting lines formed in the upper and lower walls of the extrusion during the separation process.

Abstract: A method for forming a heat exchanger assembly including wrapping a one-piece heat exchanger tube onto a heat transfer unit having a plurality of fins on upper and lower surfaces, the fins being provided with notches which are aligned in sets with each set of notches receiving a section of the heat exchanger tube as it is wrapped around the heat transfer array, return bend portions of the heat exchanger tube being formed in the wrapping process to have a generally rectangular cross section to maximize the cross sectional area of the heat exchanger tube in the return bend areas of the tube.

Abstract: A heat exchanger assembly of the side-entry cross-fin type includes first and second integral fin units, each comprising a single sheet of material provided with a plurality of aligned apertures, the sheet of material being folded in accordian-fashion such that the apertures define a plurality of notches arranged in rows which extend longitudinally of the fin unit. Two of the fin units are assembled together with a single length of heat exchange tube which threads the notches of the fin units, the tube extending over an oval-shaped helical path through the two fin units. In another embodiment, a single folded fin unit is provided with notches in fins on its upper and lower surface, a single length of tube being wrapped around the single fin unit threading the apertures therein, the tube extending in a generally oval-shaped helix path.

Abstract: A heat transfer unit includes an elongated finned tubular element bent in a serpentine pattern with the thickness of the wall of the tubular member made greater at return bend portions than at cross portions either by more shallow cutting of the rib material from which the fins are formed at the return bend portions than at the cross portions, or by crimping the tubular member at the return bend portions prior to cutting the fins so that a portion of the rib material from which the fins are cut is compressed inwardly on both sides of the tubular member to increase the wall thickness of tube material at the return bend portions.

Abstract: A heat exchanger assembly of the side-entry cross-fin type includes first and second integral fin units, each comprising a single sheet of material provided with a plurality of aligned apertures, the sheet of material being folded in accordian-fashion such that the apertures define a plurality of notches arranged in rows which extend longitudinally of the fin unit. Two of the fin units are assembled together with a single length of heat exchange tube which threads the notches of the fin units, the tube extending over an oval-shaped helical path through the two fin units. In another embodiment, a single folded fin unit is provided with notches in fins on its upper and lower surface, a single length of tube being wrapped around the single fin unit threading the apertures therein, the tube extending in a generally oval-shaped helix path.