Method of making soldered joints

Claim 2

In a method of making a tubular joint between the ends of two tubular members, at least one of which comprises aluminum, the steps including: A. forming the end of said members to be joined of a size to enable the ends to be telescoped with a clearance space therebetween; B. applying an adherent coating of solidified solder to the end of at least one of said members; C. inserting the end of one of said members into the end of the other of said members, so that the coating of solidified solder is present in the clearance space between the overlapping portion of the ends of the inner and outer telescoped members; D. positioning the telescoped members so that the open end of the outer of the members is disposed downwardly; E. submerging the downwardly disposed open end of the outer of the two telescoped members into molten solder to heat the assembled members and the coating of solder therebetween to at least the melting point of the solder, and to thereby break the surface tension of the solder at the region of the joint by melting and flowing of the solidified solder coating, thereby causing molten solder to flow into and fill the region between the two members; F. directly applying ultrasonic energy to only the molten solder while the inserted ends of the members lie in the ultrasonic energy field in the molten solder, whereby the ultrasonic energy penetrates into the clearance space between the joint members to clean the inner surfaces of the members; and G. withdrawing thE members from the molten solder, and cooling them to solidify the solder in the clearance space between the members to form a joint therebetween.

Claim 3

A method as defined in claim 1 wherein the step of applying coating of solder to the end of one of said members includes submerging the end of that member in molten solder; and applying ultrasonic energy to the molten solder while the end of the member is submerged therein.

Claim 4

A method as defined in claim 1 wherein the step of inserting the end of one of the members into the end of the other of the members includes axially applying force of sufficient magnitude to the members to frictionally retain the members in assembled relation during subsequent processing.

Claim 5

A method as defined in claim 1 wherein the step of forming the ends of said members includes forming a bell with a tapering portion on one of the members, said tapering portion having an interior dimension smaller than the corresponding exterior dimension of the other of said members; and wherein the step of inserting the end of the other of said members into the bell formed on said one member includes forcing the members together so as to frictionally retain the members in assembled relation during subsequent processing.

Claim 6

A method as defined in claim 1 wherein the step of applying an adherent coating of solder to at least one of said members includes applying said adherent coating to the end of the inner of said members an axial distance greater than the area of overlap between the members when they are assembled so that the solder coating extends downwardly from the downwardly disposed open end of the outer member when the assembled members are submerged in molten solder, to thereby afford a region of substantial area for comingling of the heated coating of solder and the molten solder surrounding it, facilitating breaking of the surface tension of the molten solder at its interface with the clearance space between the joint members.

Claim 7

A method as claimed in claim 1 wherein the step of submerging the inserted ends of the members into molten solder includes disposing the bottom end of the outer of the inserted members below the surface of the molten solder while the upper end of the inner of the inserted members lies above the level of molten solder.

Claim 8

In a method of joining a plurality of return bend members to the ends of a plurality of heat exchange tube members of a heat exchanger, wherein the ends of said tube members are formed of sufficient size to receive the ends of said return bend members with a clearance space therebetween, the steps including: A. applying an adherent coating of solder to the ends of at least one of said members; B. inserting and temporarily securing the ends of the return bend members into the ends of the heat exchange tube members with the adherent layer of solder disposed in the clearance space between the overlapping ends of said members, thereby providing a plurality of return bends assembled with the heat exchanger; C. positioning the heat exchanger so that ends of the heat exchange tube members open downwardly; D. lowering the ends of the heat exchange tube members, having the return bend members inserted therein, into molten solder to heat the adherent layer of solder to its melting point, whereby the melting of the adherent coating of solder breaks the surface tension of the molten solder at the region of the inserted ends of the members so that molten solder is enabled to flow into the clearance space between the inserted ends of the members; E. applying ultrasonic energy to only the molten solder while the inserted ends of the members lie in the ultrasonic energy field in the molten solder, whereby the ultrasonic energy penetrates into the clearance space between the joint members to clean the inner surfaces thereof; and F. withdrawing the heat exchanger from the molten solder and cooling it to solidify solder in the clearance space between the heat exchange tube and the Return bend members and form a permanent joint therebetween.

Claim 9

In a method of joining a plurality of return bend members to the ends of a plurality of heat exchange tube members of a heat exchanger, wherein the ends of said tube members are formed of sufficient size to receive the ends of said return bend members with a clearance space therebetween, the steps including: A. applying an adherent coating of solder to the ends of at least one of said members; B. inserting and temporarily securing the ends of the return bend members into the ends of the heat exchange tube members with the adherent layer of solder disposed in the clearance space between the overlapping ends of said members, thereby providing a plurality of return bends assembled with the heat exchanger; C. positioning the heat exchanger so that ends of the heat exchange tube members open downwardly; D. lowering the ends of the heat exchange tube members, having the return bend members inserted therein, into molten solder to heat the adherent layer of solder to its melting point, whereby the melting of the adherent coating of solder breaks the surface tension of the molten solder at the region of the inserted ends of the members so that molten solder is enabled to flow into the clearance space between the inserted ends of the members; E. applying ultrasonic energy to only the molten solder while the inserted ends of the members lie in the ultrasonic energy field in the molten solder, whereby the ultrasonic energy penetrates into the clearance space between the joint members to clean the inner surfaces thereof; and F. withdrawing the heat exchanger from the molten solder and cooling it to solidify solder in the clearance space between the heat exchange tube and the Return bend members and form a permanent joint therebetween.

Claim 10

A method as defined in claim 7 including the step of forming a bell on the ends of said heat exchange tube members with a tapering portion, said tapering portion having a portion having an interior dimension smaller than the corresponding exterior dimension of the other of said members; and wherein the step of inserting the end of the return bend members into the bells formed on said heat exchange tube member includes forcing the members together so as to frictionally retain the members in assembled relation during subsequent processing.

Claim 11

A method as defined in claim 7 wherein the step of applying an adherent coating of solder to at least one of said members includes applying said adherent coating to the end of the inner of said members an axial distance greater than the area of overlap between the members when they are assembled so that the solder coating extends downwardly from the downwardly disposed open end of the outer member when the assembled members are submerged in molten solder, to thereby afford a region of substantial area for comingling of the heated coating of solder and the molten solder surrounding it, facilitating breaking of the surface tension of the molten solder at its interface with the clearance space between the joint members.

Claim 12

In a method of joining a plurality of return bend members to the ends of a plurality of heat exchange tube members of a heat exchanger having multiple parallel rows of heat exchange tubes, wherein the ends of said tube members are formed of sufficient size to receive the ends of said return bend members with a clearance space therebetween, the steps including: A. applying an adherent coating of solder to the ends of at least one of said members; B. inserting and temporarily securing the ends of the return bend members into the ends of the heat exchange tube members, with the adherent layer of solder disposed in the clearance space between the overlapping ends of said members, thereby providing a plurality of return bends assembled with the heat exchanger which lie in parallel planes; C. positioning the heat exchanger so that ends of the heat exchange tube members open downwardly; D. lowering the ends of the heat exchange tube members, having the return bend members inserted therein, into molten solder to heat the adherent layer of solder to its melting point, whereby the melting of the adherent coating of solder breaks the surface tension of the molten solder at the region of the inserted ends of the members so that molten solder is enabled to flow into the clearance space between the inserted ends of the members; E. passing the ends of the heat exchange tube members, having return bend members inserted therein, along a path parallel with the planes of said plurality of return bends, past a plurality of ultrasonic transducers disposed in the molten solder, so that the return bends pass between adjacent ultrasonic transducers in spaced relation therewith; F. applying ultrasonic energy to only the molten solder while the inserted ends of the members lie in an ultrasonic field in the molten solder, whereby the ultrasonic energy penetrates into the clearance space to clean the inner surfaces of the members; and G. withdrawing the heat exchanger from the molten solder and cooling it to solidify solder in the clearance space between the heat exchange tube and return bend members and form a permanent joint therebetween.

Claim 13

In a method of joining a plurality of return bend members to the ends of a plurality of heat exchange tube members of a heat exchanger having multiple parallel rows of heat exchange tubes, wherein the ends of said tube members are formed of sufficient size to receive the ends of said return bend members with a clearance space therebetween, the steps including: A. applying an adherent coating of solder to the ends of at least one of said members; B. inserting and temporarily securing the ends of the return bend members into the ends of the heat exchange tube members, with the adherent layer of solder disposed in the clearance space between the overlapping ends of said members, thereby providing a plurality of return bends assembled with the heat exchanger which lie in parallel planes; C. positioning the heat exchanger so that ends of the heat exchange tube members open downwardly; D. lowering the ends of the heat exchange tube members, having the return bend members inserted therein, into molten solder to heat the adherent layer of solder to its melting point, whereby the melting of the adherent coating of solder breaks the surface tension of the molten solder at the region of the inserted ends of the members so that molten solder is enabled to flow into the clearance space between the inserted ends of the members; E. passing the ends of the heat exchange tube members, having return bend members inserted therein, along a path parallel with the planes of said plurality of return bends, past a plurality of ultrasonic transducers disposed in the molten solder, so that the return bends pass between adjacent ultrasonic transducers in spaced relation therewith; F. applying ultrasonic energy to only the molten solder while the inserted ends of the members lie in an ultrasonic field in the molten solder, whereby the ultrasonic energy penetrates into the clearance space to clean the inner surfaces of the members; and G. withdrawing the heat exchanger from the molten solder and cooling it to solidify solder in the clearance space between the heat exchange tube and return bend members and form a permanent joint therebetween.

Claim 14

A method as defined in claim 10 including the step of forming a bell on the ends of said heat exchange tube members with a tapering portion, said tapering portion having a portion having an interior dimension smaller than the corresponding exterior dimension of the other of said members; and wherein the step of inserting the end of the return bend members into the bells formed on said heat exchange tube member includes forcing the members together so as to frictionally retain the memberS in assembled relation during subsequent processing.

Claim 15

A method as defined in claim 10 wherein the step of applying an adherent coating of solder to at least one of said members includes applying said adherent coating to the end of the inner of said members an axial distance greater than the area of overlap between the members when they are assembled so that the solder coating extends downwardly from the downwardly disposed open end of the outer member when the assembled members are submerged in molten solder, to thereby afford a region of substantial area for comingling of the heated coating of solder and the molten solder surrounding it, facilitating breaking of the surface tension of the molten solder at its interface with the clearance space between the joint members.