Abstract: Welded structures having a first and a second member formed from sheet metal, tubes, and similar shapes, are economically fabricated through use of a method for joining a second member to a first member having a folded rim extending therefrom. The folded rim defines an air gap within the folded rim. The first and second members are joined together by forcing the folded rim against the second member under sufficient pressure to flatten the folded rim to a point that there remains substantially no air gap inside the folded rim, and resistance welding together the first and second members. The second member and the rim respectively define faying surfaces thereof. The air gap inside the folded rim extends generally parallel to the faying surfaces. The faying surfaces of the rim and second member are forced against one another by applying pressure through the folded rim in a direction generally perpendicular to the faying surfaces.

Abstract: Welded structures having a first and a second member formed from sheet metal, tubes, and similar shapes, are economically fabricated through use of a method for joining a second member to a first member having a folded rim extending therefrom. The folded rim defines an air gap within the folded rim. The first and second members are joined together by forcing the folded rim against the second member under sufficient pressure to flatten the folded rim to a point that there remains substantially no air gap inside the folded rim, and resistance welding together the first and second members. The second member and the rim respectively define faying surfaces thereof. The air gap inside the folded rim extends generally parallel to the faying surfaces. The faying surfaces of the rim and second member are forced against one another by applying pressure through the folded rim in a direction generally perpendicular to the faying surfaces.

Abstract: A first method for metallurgically attaching together two members. A first member is obtained having a through hole and having a longitudinally-projecting flange surrounding the through hole. A second member is obtained having a transversely-projecting annular rim. The second member is at least partially positioned in the through hole of the first member with the flange of the first member projecting away from the rim. The first and second members are resistance welded together, wherein after the weld is created, the rim of the second member is seated on the first member. In an other method, which is similar to the first method, the second member has no rim.

Abstract: A first method for metallurgically attaching together two members. A first member is obtained having a through hole and having a longitudinally-projecting flange surrounding the through hole. A second member is obtained having a transversely-projecting annular rim. The second member is at least partially positioned in the through hole of the first member with the flange of the first member projecting away from the rim. The first and second members are resistance welded together, wherein after the weld is created, the rim of the second member is seated on the first member. In an other method, which is similar to the first method, the second member has no rim.

Abstract: A battery terminal for a battery case is formed with a circumerentially extending shoulder which engages the inner surface of the battery case when the terminal is installed in an aperture in the case by inserting the terminal in the aperture from the inside of the battery case. A retaining ring is then interference resistance welded to the terminal as the retaining ring is pressed into a seated position against the outer surface of the case. An o-ring seal on the shoulder engages the inner surface of the battery case and seals against leakage of the battery acid. High pressure deformation of the battery case and resulting creep are significantly reduced because the force that is used to press the retaining ring against the outer surface of the battery case is relatively low. Furthermore, the welded joint is almost as strong as the material that the terminal is made of and stronger than the plastic battery case.

Abstract: The specification discloses an electronic dynamic balance leak testing system utilizing a "live zero", wherein a source of test medium at a predetermined desired pressure or vacuum is connected to a part to be tested, and after the part is filled with the test medium, and an interval is provided for the system to stabilize the affects due to wave front oscillations, the test part is momentarily isolated from said test media and a microcomputer system is utilized, both to cause said isolation, and to measure the differential pressure existing at two points during the test. In a modification of our system which can dynamically project leak and accept or reject parts much sooner because of this projection feature, the rate of change of the differential pressure transducer is examined and is compared to a curve which is characteristic of the rate of change of a volume which is experiencing a predominately leak based change of pressure.