A centrifugal fan is provided that includes a main plate configured to be rotated about a rotational axis, a shroud, having a suction opening, and a plurality of blades arranged in a circumferential direction between the main plate and the shroud to allow air suctioned in through the suction opening to flow from a front edge to a rear edge of each blade. Assuming a first cross section, a second cross section, a third cross section, and a fourth cross section of each blade sequentially taken at layers from the shroud to the main plate, a front edge of the first cross section is located farther from the rotational axis than a front edge of the fourth cross section, and a rear edge of the first cross section is located closer to the rotational axis than a rear edge of the fourth cross section.

A method of manufacturing a blank which uses direct electric heating includes: pressing electrodes on both sides of the blank and heating the blank by applying current to the blank; hot-forming the heated blank; trimming the formed blank; and loading the trimmed blank. An apparatus for manufacturing the blank includes a pair of first electrode units on both surfaces of a side of the blank to press the surfaces, a pair of second electrode units on both surfaces of the other side of the blank, a pressing unit pressing the first electrode units or the second electrode units on the blank, a cooler cooling portions around the first electrode units or the second electrode units, and a power supply control unit heating the blank up to a predetermined temperature.

Heat resistant, highly conductive electrochemical cells for high temperature applications and methods of their assembly are described herein. The cells have at least two electrodes and at least one separator enclosed in heat resistant ceramic enclosure with metalized terminals on its bottom. Methods of the electrodes' tabs welding to inside connectors and the electrodes' coating are also disclosed. The resulting cells are solderable to circuit boards or various circuits.

A jointing device for metal mask plate welding includes a jointing device body. A height of the jointing device body is smaller than a welding height of a welding gun. The jointing device body has a through-hole corresponding to a welding area of a metal mask. A width of the through-hole is larger than a welding spot diameter of the welding gun. The jointing device body is used for jointing the metal mask to a metal mask receiving frame.

According to one or more embodiments of the present invention, a method for fusing metal nanowire junctions in a conductive film includes applying a constant current through the conductive film including a plurality of metal nanowires and a plurality of metal nanowire junctions, or conducting an ultrasonic welding of the metal nanowire junctions.

A wire butt welding apparatus includes at least two clamps, individual ones of the at least two clamps configured to hold a respective wire. The individual ones of the at least two clamps are positioned within the wire welder such that the ends of individual ones of the respective wires, when held by the respective clamps, will contact each other. One or more individual ones of the at least two clamps are associated with an adjustment axis about which the individual ones of the at least two clamps are configured to rotate. An adjustment mechanism is operatively coupled to fix one or more of the at least two clamps corresponding to the associated adjustment axis at an angular orientation with respect to a second clamp.

Resistance spot welding is performed on a combination of overlapping steel sheets including at least one steel sheet that has, on a surface thereof, a coated layer with zinc as a main component, by (1) starting electric current passage in a state satisfying 0.9tL1.1t; and (2) dividing electric current into main current and initial current that precedes the main current and is two-step current, setting a current value I.sub.1 during current in a first step of the initial current to satisfy I.sub.m1.1I.sub.115.0 kA with respect to a current value I.sub.m during the main current, and setting a current value I.sub.2 in the subsequent second step to no current or low current satisfying 0I.sub.2I.sub.m0.7.

A method for welding a stack of sheets having a plurality of sheets of different materials is provided. In an aspect, the stack of sheets includes an aluminum sheet and a galvanneal steel sheet. In an aspect, the method includes resistively spot welding the galvanneal sheet to a hot-stamped steel sheet placed between the aluminum sheet and the galvanneal sheet, the sheet of hot-stamped steel including stress relief sections. The method further includes placing a metal foil on the aluminum sheet and vaporizing the metal foil to project portions of the aluminum sheet through the stress relief sections of the hot-stamped steel sheet to weld the portions of the aluminum sheet to the galvanized steel sheet. In another aspect, the method includes placing the metal foil on a raised portion of the aluminum sheet and projecting the raised portion of the aluminum onto the galvanneal steel sheet.

A method of joining a first tin-plated electrical component to a second tin-plated electrical component, and components joined to exhibit reduced stress levels at the joined location. The method includes defining a pocket in the second component that is shaped to accept a portion of the first component, placing the portion of the first component substantially within the pocket to define an interfacial region, and using a resistance welder to both form a solid-state diffusion bond along at least a portion of the interfacial region and fill a substantial remainder of the interfacial region with melted tin plating from one or both of the first and second components.

A hot press welding head includes a main body having a front side surface and a rear side surface opposite to each other in its transverse direction, and a curved bottom surface between bottom edges of the front side surface and the rear side surface. The bottom edge of the front side surface is lower than the bottom edge of the rear side surface in a height direction of the main body. Multiple positioning slots are formed on the curved bottom surface. The multiple positioning slots are arranged in a row along a longitudinal direction of the main body for simultaneously positioning multiple welded wires. The positioning slot extends along the transverse direction of the main body between the front side surface and the rear side surface.