Mitsubishi Denki Kabushiki Kaisha

Wataru Shimada

Susumu Hoshinouchi

Kazumichi Machida

Seigo Hiramoto

Masaru Okada

Akio Yoshida

Kenji Kawaguchi

A T-shape joint includes a slant gap formed between joint faces of a vertical base metal and a horizontal base metal and the slant gap is filled perfectly with a brazing alloy without remaining any defect. The slant gap can be saw tooth shape gaps. The slant gap can be formed in the thickness direction of the vertical base metal. The molten brazing metal penetrates into the slant gap without forming a cavity for a stronger joint.

T-Shape joint and preparation thereof

In producing a motion picture screen from a workpiece by forming a surface with a number of continuously smoothly connected minute projections, a two-dimensional cutter which has a cutting edge constituted by a number of circular arcs connected together in a smooth wavy form lengthwise, each of the arcs having a predetermined curvature .rho..sub.1 and a predetermined central angle .theta..sub.1, and the centers of the neighboring arcs being on opposite sides of the cutting edge, is used to machine the surface of the workpiece by a relative movement between the workpiece and the cutter. A surface is machined that has in a section perpendicular to the length of the cutter a number of circular arcs connected together in a smooth wavy form lengthwise, each of the arcs having a predetermined curvature of .rho..sub.2 and a predetermined central angle .theta..sub.2 and the centers of the neighboring arcs being on opposite sides of the line. The workpiece thus machined can have aluminum, etc. applied to it by a vacuum evaporation process, etc. to be directly used as a motion picture screen. Alternatively, the machined workpiece can be used as a mould or die for producing a motion picture screen by pressing a metal foil having a high reflecting property, e.g. an aluminum foil, etc. against the machined surface, the foil forming the motion picture screen.

Method for producing a motion picture screen

One metallic plate is set upright on another metallic plate and a filler fills each corner formed of both plates. A deposit metal is deposited on and adjacent to each filler to weld the plates to form a recess on that portion to the deposit metal facing a non-welded portion located between the welded plates. Alternatively the recess may be formed by supplying an inert gas to a space formed between the two plates and simultaneously depositing a deposit metal on the plates across the space.

Method of producing welded joint including non-welded portion

An arc welding apparatus and method is described which includes a guide nozzle surrounding a non-consumable electrode and a shielding nozzle disposed outside the guide nozzle so as to feed a protecting inert gas about the electrode from a position within the guide nozzle and to feed a shielding carbon dioxide gas or a mixture of carbon dioxide gas and oxygen or other inert gas from a position within the shielding nozzle, whereby the electrode is protected by means of the guide nozzle and the protecting gas supplied therethrough and the outer portion of the arc is cooled to restrict the radial extent thereof by the shielding gas, while a deoxidizing reaction with the melted metal may be performed by means of the carbon dioxide gas and a deoxidizing agent within a welding rod when the latter is employed between the electrode and a base metal, or in the vicinity of the welding arc.

Arc welding apparatus and method

In a brazing method of brazing a joint at the contacted surfaces of two base metals, the surfaces of the base metals are arc heated to the optimum brazing temperature of higher than a melting point of a brazing alloy and lower than a melting point of the base metal with the temperature gradient gradually lowering from one end to the opposite end, while feeding the brazing alloy from the end in the lower temperature side into the clearance between the contacted surfaces of the base metals or disposing the brazing alloy in the clearance before heating. A soft plasma arc is used as the heat source to heat the joint from one end to the opposite end.

Brazing method

A method of removing surface defects from the surface of a steel product, such as a slab designed for rolling, wherein the defects are melted by an arc generated by an arc welding apparatus having a non-consumable electrode, a guide nozzle about the electrode to maintain an inert gas atmosphere immediately thereabout, and a shield nozzle about the guide nozzle to inject a mainly carbon dioxide gas therefrom, and a deoxidizer is applied to the molten pool formed in the welding operation so as to cover the surface thereof with a slag formed by the deoxidizer which is oxidized.

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Amagasaki, Japan

Wataru Shimada