Abstract: This invention has as its object to facilitate determination of a weld strength of welded target members when a plurality of metal members are welded. In order to achieve this object, when a plurality of metal members are welded, a weld strength of the welded target members is determined on the basis of the state of a lower bead.

Abstract: This invention has as its object to facilitate determination of a weld strength of welded target members when a plurality of metal members are welded. In order to achieve this object, when a plurality of metal members are welded, a weld strength of the welded target members is determined on the basis of the state of a lower bead.

Abstract: The object of this invention is to provide a cylindrical member welding method that can weld a cylindrical member without causing cracking. In order to achieve this object, in a cylindrical member welding method of welding, to an end portion of a cylindrical first member containing aluminum as a major component, a cylindrical or disk-like second member having substantially the same outer diameter as that of the first member and containing aluminum as a major component, a space is formed on a slightly inner side of an outer circumferential surface of a welded portion of the first and second members.

Abstract: To prevent formation of a white streaking line on an image by a blade member for a developing unit in an image forming apparatus, a blade member is formed by welding magnetic and nonmagnetic members to each other by laser irradiation. The laser beam is pulsed so that the laser beam irradiating a welding portion is in-focus or out-of-focus.

Abstract: A typewriter ribbon lifting mechanism includes a holder supporting a printing ribbon and a correction ribbon below the printing ribbon. The holder is vertically tiltable for lifting the printing or correction ribbon selectively from its inoperative position to its operative position. The holder is normally held in its lowered inoperative position. A cam follower is secured to the holder and supports an axially movable follower pin thereon. A ribbon lift cam is rotatable only in one direction to cause the cam follower to tilt the holder vertically. The cam has a first cam groove in which the follower pin is engageable to raise the holder to place the printing ribbon in its operative position, and a second cam groove in which the follower pin is engageable to raise the holder to place the correction ribbon in its operative position. The second cam groove has a portion which forms a part of the first cam groove, while the remaining portion of the second cam groove is greater in depth than the first cam groove.

Abstract: A surface treating process for alkali glass to prevent "whitening" thereof. The method comprises bringing the surface of glass into contact with an aqueous solution containing one or more metal nitrates, the nitrate being of a metal selected from the group consisting of iron, nickel, chromium and cobalt.