Abstract: A method of manufacturing a metallic tube with a spiral fin for use as a heat transfer tube of a heat exchanger and the like. A solid metallic bar or metallic elementary hollow bar provided with a small hole is supplied to an inclined rolling mill having a plurality of rolls provided with a plurality of annular grooves formed on an outer circumferential surface thereof, and the solid metallic bar or metallic elementary hollow bar is worked into a pierced hollow bar by piercing rolling by means of a piercing plug and at the same time a fin is formed on an outer circumferential surface of the pierced hollow bar to integrate the fin with a body of the tube. Accordingly, the piercing rolling and the formation of the fin on the outer circumferential surface of the tube can be carried out at the same time, so that the manufacturing process can be remarkably shortened and the productivity can be high.

Abstract: A metal case for housing electronic parts including an IC and a manufacturing method therefor are disclosed. The case comprises a shallow vessel having a wall on its periphery which is formed from metal sheet having the same thickness as the bottom of said depression and a rectangular metal ring which has a contour such that it can fit into the wall of said shallow vessel, said rectangular metal ring being fit into said shallow vessel and connected thereto so as to form a single body.

Abstract: In a method of manufacturing seamless tubes according to the present invention, piercing from a solid billet can be accomplished through one pass by means of a piercing mill ao the present invention, piercing from a solid billet can be accomplished through one pass by means of a piercing mill at the piercing ratio above 4.0 or the expansion ratio above 1.15, or the wall thickness/outside diameter ratio below 6.5%, and the piercing mill having cone-shaped rolls is used with its feed angle .beta. and cross angle .gamma. satisfying the following relations,8.degree..ltoreq..beta..ltoreq.20.degree.5.degree..ltoreq..gamma..ltoreq.35.degree.15.degree..ltoreq..beta.+.gamma..ltoreq.50.degree.and the solid billet diameter d.sub.o, outside diameter d and wall thickness t of a hollow shell after piercing satisfying a prescribed condition for realization, thereby manufacturing equipments can be largely simplified.

Abstract: A continuous rolling mill is constructed by arranging driven horizontal rolling mills and undriven vertical rolling mills alternately and determining the values of the thickness of the rolled material between adjacent stands, the interaxial distance between work rolls, and the diameter of the work roll to satisfy predetermined relationships.

Abstract: An I-beam is made lighter in weight by corrugating the central portion of its web. Dimension of the corrugating is determined by predetermined experimental equations. The corrugating work is performed by a pair of complementary intermeshing rolls having the same dimensions.

Abstract: The invention relates to a method of manufacturing solid metallic materials having a circular cross section by employing a rotary mill. A three or four roll cross-type rotary mill is employed, with cross and feed angle setting selected so as to meet specific conditions. The method permits efficient production of metallic materials without internal cracks or internal fracture initiated from porosity. In one version of the method the material being worked is rotated. In another version the material is not rotated and the roll housing is rotated around the former. Where the latter version is employed, it is possible to work the material as produced by a continuous casting machine and without cutting.

Abstract: A method of manufacturing hollow rods of very thick wall, in which wall thickness to outside diameter ratio is 25% or more, such as those used as work stock for manufacturing oil-well drilling collars. A cross-type or rotary mill having three or four cone-type rolls is employed without using internal sizing tools such as plug or the like, whereby a hollow work piece is worked and reduced in both outside diameter and wall thickness to the target values. In order to obtain higher dimensional accuracy and to prevent deterioration of the work material in mechanical properties, the cross angle should be positive and the feed angle should be set within the range of 3.degree..ltoreq..beta..ltoreq.20.degree..

Abstract: The invention relates to a method of rotary piercing in seamless tube manufacturing under a rotary piercing process, such as Mannesmann mandrel mill process. Rotary piercing operation is carried out by employing a rotary piercing mill having a pair of cone-shaped main rolls adapted to cooperate with a plug for rotary piercing and disc rolls disposed in opposed relation between the pair of main rolls and adapted to press hollow shell on the surface thereof. In this method of rotary piercing, the main rolls have feed and cross angles designed to meet certain conditions individually and in combination. The method makes it possible to carry out rotary piercing of less hot workable and/or extremely hard-to-work materials, that is, high-alloy steel billets, without surface torsional deformation and circumferential shear deformation. Thus, it is possible to manufacture high quality tubes of high-alloy steels free from outside seams and inside bore defects.

Abstract: A rough rolling process for forming a beam blank for a universal beam from a flat slab, comprises the steps of making a triangular slit of a predetermined apical angle in each of longitudinal side edges of said flat slab and gradually deepening said slit with the apical angle thereof fixed; and widening the slit after the depth of said slit has reached a predetermined value.

Abstract: The present invention relates to the manufacture of seamless metal tubes by a cross-roll helical rolling process such as Mannesmann mandrel mill process or by a press piercing process such as Ugine Sejournet process. Shells being worked are subjected to outside-diameter reduction by means of a rotary mill having 3 or 4 rolls, without using internal tools such as plug and mandrel bar, so that wall eccentricity is significantly improved, which fact assured higher quality of finished product.

Abstract: This invention provides yellow-developing couplers for use in diazo copying materials, which couplers are superior in light fastness and are expressed by the general formula: ##STR1## wherein X and Y represent hydrogen atom, halogen, or alkyl radical or alkoxy radical having 1 to 6 carbon atoms.

Abstract: An internal combustion engine fuel saving control system is disclosed in which acceleration of a vehicle is initiated in a region of high engine efficiency, i.e., low fuel consumption, and continues until the actual vehicle speed equals a first preset speed which is greater than the desired traveling speed of the vehicle. When the control system detects that the actual vehicle speed is at the first preset speed, the vehicle engine is stopped (turned off) and the vehicle coasts, thereby producing vehicle deceleration. When the control system further detects that the actual vehicle speed of the coasting vehicle reaches a second preset speed which is less than the desired traveling speed, the vehicle engine is started and acceleration is again initiated. The acceleration-deceleration operation is continuously repeated resulting in an average vehicle speed which equals the desired vehicle traveling speed.