Abstract: A joining structure includes: a first tube made of a first metal or alloy; a second tube made of a second metal or alloy different from the first metal or alloy; a coupling member having a cylindrical shape to provide therein a passage into which the first and second tubes are insertable, and having an opening on a side face thereof to penetrate into the passage; and a brazing material injected into the passage through the opening with an end face of the first tube and an end face of the second tube abutting on each other in the passage to braze the first tube, the second tube, and the coupling member. The second metal or alloy is more easily oxidizable than the first metal or alloy during brazing. An abutting position between the first and second tubes is deviated from the opening toward the second tube.

Abstract: A shaping roll for melt extrusion molding used for melt extrusion molding of thermoplastic resin, the shaping roll for melt extrusion molding comprises a metal roll body, a first cylinder, and a second cylinder. The metal roll body has a heat medium passage internally. The first cylinder covers a surface of a middle portion of the roll body part. The second cylinder covers surfaces of both end portions of the roll body part. The first cylinder comprises a first metal material having a thermal conductivity of 40 W/m·K or more. The second cylinder comprises a second metal material having a thermal conductivity of 20 W/m·K or less. The first cylinder and the second cylinder are at least partially joined to each other.

Abstract: The disclosed method relates to manufacturing a heat exchanger which causes no brazing defects, and a heat exchanger manufactured by the method. The method relates to manufacturing a heat exchanger having an aluminum alloy tube defining a cooling-medium flowing passage and a copper alloy tube defining a water flowing passage, wherein a heat exchange is carried out between a cooling medium flowing through the cooling-medium flowing passage and water flowing through the water flowing passage. The aluminum alloy tube and the copper alloy tube are brazed to each other at a temperature of less than 548° C.

Abstract: Methods of applying aluminum coating layers over copper wires are disclosed. A first method may include applying aluminum powder to the surface of a rod, passing the rod through a first set of compression rolls thereby forcing the aluminum powder into a compacted preform around the rod, and heating the rod covered by the preform at 550° C. to 620° C. Further, the heated preform coated rod is passed through a second set of compression rolls thereby obtaining an aluminum coated copper rod. A second method includes disposing a copper rod inside an aluminum tube having an inner layer formed of brazing aluminum alloy, reducing the diameter of the tube's inner surface to match the copper rod, and heating the composite tube-rod such that the inner layer of the brazing alloy fuses to the rod. Another method includes passing the copper rod through a spray of metallic aluminum.

Abstract: A system for securing a mold blade to a mold segment includes a plurality of pins placed across the length of the mold blade and a plurality of corresponding recesses on an inner surface of the mold segment. Each pin is placed within a recess securing the mold blade to the mold segment.

Abstract: The process that is the subject of this invention is a method of making a rotary sputtering target having the steps of providing a cylinder of sputtering target material having an adhesion-wetting layer on its inside surface; providing a stainless steel sputtering target backing tube having an outside diameter smaller than the sputtering target material inside diameter, the backing tube having an adhesion-wetting layer on its outside surface; welding an upper and lower stainless steel retaining ring to the backing tube adjacent to the sputtering target material so that the target material is in compression and the backing tube in tension; and introducing molten bonding material into the annulus between the backing tube and the sputtering target material.

Abstract: A method for setting a protective coating on the inner wall of a tube includes providing a cylindrical sleeve, then setting on the outer surface of the sleeve a layer of a thermo fusible material, then machining the sleeve to provide it with an external diameter corresponding to the tube internal diameter, positioning the sleeve in the tube, and finally soldering the sleeve on the tube by applying heat.

Abstract: A Coriolis flowmeter having a single flow tube surrounded by connecting rings and a balance bar whose ends are connected by the connecting rings to the flow tube. The balance bar has a thermal coefficient of expansion greater than that of the connecting rings and the flow tube. The outer circumferential surface of each connecting ring is tapered toward the axial center of the flow tube. The inner circumferential surface of the balance bar has a taper matching that of the connecting ring. The connecting ring can only be partially inserted into the space between the flow tube and the balance bar when the assembly is at room temperature. Braze material is then applied to the visible ends of the surface common to the balance bar and the connecting rings as well as to the ends of the surface common to the connecting rings and the flow tube. The structure is heated to brazing temperature to braze these common surfaces.

Abstract: A method for manufacturing a welded cylinder is provided wherein a seal (such as an O-ring seal or a cured polymeric sealant) is disposed between the tube of a cylinder and its welded end plug. The seal is spaced away from the circumferential weld that joins the end plug to the cylinder to reduce the hoop stress in the tube adjacent the weld, thereby reducing the tensile stress at the weld joint.

Abstract: A heating furnace tube, a method of using the same and a method of manufacturing the same which have been developed with a view to eliminating inconveniences occurring when a carbon-containing fluid is made to flow in the heating furnace tube. The heating furnace tube which comprises a rare earth oxide particle distributed iron alloy containing 17-26 wt. % of Cr and 2-6 wt. % of Al. The method of manufacturing this heating furnace tube which comprises the steps of forming or inserting an insert metal on or into at least one of a joint end portion of one heating furnace tube element and that of the other heating furnace tube element, bringing these two joint end portions into pressure contact with each other directly or via an intermediate member, and diffusion welding the two heating furnace tube elements to each other by heating the insert metal.

Abstract: A tubular part is brazed into coaxial relationship with the bore in a metal body part having a counterbore for receiving the tubular part. In a first embodiment a tubular sleeve is fitted within the bores of the metal body and the tubular part. The parts are then heated and vibrated while the braze material is melted. In a second embodiment a frustoconical plug is inserted into the coaxial bores of the parts and the parts are again heated and vibrated. The parts are allowed to cool until the braze material hardens, after which the vibration is terminated. The remaining sleeve or plug is then machined out of the two bores leaving the tubular part brazed to the metal body.

Abstract: A tubular part is brazed into coaxial relationship with the bore in a metal body part having a counterbore for receiving the tubular part. In a first embodiment a tubular sleeve is fitted within the bores of the metal body and the tubular part. The parts are then heated and vibrated while the braze material is melted. In a second embodiment a frustoconical plug is inserted into the coaxial bores of the parts and the parts are again heated and vibrated. The parts are allowed to cool until the braze material hardens, after which the vibration is terminated. The remaining sleeve or plug is then machined out of the two bores leaving the tubular part brazed to the metal body.

Abstract: A tubular part is brazed into coaxial relationship with the bore of a second part having a counter bore for receiving the tubular part by providing a tubular sleeve within the bores of the two parts prior to brazing. After the braze material has cooled the tubular sleeve and any braze material around it is machined out of the bores. In a second embodiment a tubular part is brazed into a recess of the second part before a bore is drilled therein. After the parts are brazed together the bore is drilled through both the tubular part and the second part.

Abstract: A method of manufacturing a clad product in which a metallic substrate material is extruded and a cladding material is then brought into intimate contact with the heated extrudate before the extrudate has had an opportunity to cool to room temperature. The cladding material is compressed against the heated extrudate, thereby bonding the cladding material to the substrate material and forming the clad extruded metallic product. The clad extruded metallic product is then cooled to room temperature.

Abstract: A pair of soldering irons are fixed to a sliding plate at a predetermined interval. The soldering irons are integrally moved so as to reciprocate in a rectangular direction relative to a conveyor belt. One of the soldering irons is conveyed to a working position of the conveyor belt and the other of them is separated from the conveyor belt. While one of the soldering irons solders a circuit board, the other is cleaned. The circuit board has a slit into which a metal plate is inserted and soldered. For the slit, a soldering land constituted of a main-land and a sub-land is provided. The main-land is formed along one of longer sides of the slit. The sub-land is elongated from the main-land along a shorter side of the slit. The soldering land is not formed all around the slit so that the slit is not closed by solder when the circuit board is dip-soldered.

Abstract: A method of manufacturing a hollow spindle, especially for the pivotal mounting of valve-actuating levers to control exhaust-and-intake valves of an internal combustion engine. The spindle has an outer tube, in the interior of which a shaped tubular body is fixed in order to form at least two liquid-carrying chambers. To form a chamber, the tubular body is provided with a cutout extending in the longitudinal direction. The tubular body is a shaped inner tube that, seen in cross-section, has an inwardly-curved region that makes a rounded and stepless transition to the circular region, and of the tubular body. At least the circular region is joined by virtue of its material to the outer tube.

Abstract: The invention provides methods of manufacturing stainless steel tubing, pipe and shafts by utilizing air hardenable stainless steel. Such pipe, tubing and shafts have the important characteristics of low weight, shaft flex, torque, bend point and strength and have many uses. The shafts include a plurality of air hardenable metal segments of selected length, thickness and shape that are assembled into a shaft. This assembly is subsequently contacted with a brazing material and then placed into a controlled, non-oxidative atmosphere furnace of a sufficient temperature such that the assembly is simultaneously brazed and hardened. The tubing can include having a brazed lock seam which provides strength. The present invention further provides reinforcing members that are also brazed within the shaft, tubing or pipe while the outer piece is hardened.

Abstract: A method of bonding a first silicon carbide part to a second silicon carbide part is provided. The first silicon carbide part provides a receiving female joint member and the second silicon carbide part provides an insertion male joint member. The male and female members each have facing sidewalls substantially parallel to a direction in which the male member is inserted into the female member. The male and female joint members are configured to provide an average gap(s) between the facing sidewalls of the joint members which is up to about 0.003 inch (0.76 mm). The female joint member further has reservoir means for containing silicon when the male joint member is fully inserted into the female joint member, the reservoir means being in fluid communication with the gap(s). The reservoir means is filled with solid-state silicon, e.g., in powder form.

Abstract: Clad pipe having an inner pipe and an outer pipe metallurgically bonded to each other is manufactured by a process comprising the steps of: (a) preparing an inner pipe and an outer pipe made of different metallic materials, the outer pipe having an inner diameter larger than the outer diameter of the inner pipe; (b) forming an Ni-B layer by electroplating or electroless plating on the surface of one of the pipes facing the other pipe when the two pipes are assembled, the Ni-B layer having a thickness of 2-100 .mu.m and consisting essentially, on a weight basis, of B: 0.5%-7%, Fe: 0%-30%, P: 0%-7%, and a balance of Ni and inevitable impurities; (c) assembling the two pipes by inserting the inner pipe into the outer pipe; (d) subjecting the assembled pipes to cold working for reduction in diameter to such a degree that the outer diameter of the inner pipe is reduced by from 0.

Abstract: The present invention is a brazed fitting suitable for use as a hydraulic coupling for pressurized fluids. In the first embodiment, the male component has a tapered surface which mates and creates an interface with a similarly tapered surface of a female component. A brazing material is heated to diffuse and alloy within the interface, forming a connection between the surface portions which is stronger than the metal being connected. A groove on the male component retains the brazing material within the surface portions so that after the components are joined in an interference fit, the assembly is heated and the brazing material melts within the interface and connects together the mating surface by diffusing and alloying. The counterbore of the female component does not require a base, and the resulting structure has improved fluid flow characteristics.

Abstract: A stator vane assembly for a gas turbine engine that includes a plurality of circumferentially spaced ceramic vanes, each of which has an inner and outer ceramic shroud, and a ceramic post extending from one of the shrouds, and a metallic platform having a plurality of circumferentially spaced recesses. The posts are inserted into a metallic sleeve and then brazed. The brazed sleeves are then mounted in the recesses. A method for assembling these components to form the stator assembly is also described.

Abstract: The present invention is a brazed fitting suitable for use as a hydraulic coupling for pressurized fluids. A male component has a tapered surface which mates and creates an interface with a similarly tapered surface of a female component. A brazing material is heated to diffuse and alloy within the interface, forming a connection between the surface portions which is stronger than the metal being connected. A groove on the male component retains the brazing material in the middle of the surface portions so that after the components are joined in an interference fit, the assembly is heated and the brazing material melts in the middle of the interface and connects together the mating surfaces by diffusing and alloying. The counterbore of the female component does not require a base, and the resulting structure has improved fluid flow characteristics.

Abstract: An article for providing a barrier between solder in a piping joint and the interior of the piping joint so that drinking water flowing therethrough is not contaminated by lead particles resulting from water flow erosion of the solder. The barrier article comprises an annular member a portion of which engages the inner surface of an inner pipe portion and a radially outwardly extending portion of which engages the end of the inner pipe portion and extends radially beyond the outer surface of the inner pipe portion to act as a barrier between solder in the annulus between the inner and an outer pipe portion and the interior of the joint. An indicator may be provided on the inner pipe portion adjacent the joint to assure the user of the piping system that the article was installed.

Abstract: A method of manufacturing a high pressure fluid supply pipe of a double pipe structure in which an outer pipe is tightly fit over the outer circumference of an inner pipe, wherein the method comprises a step of forming a double pipe by tightly fitting an inner pipe with an outer pipe having a thermal expansion coefficient greater than that of the inner pipe while putting a brazing material therebetween, and a step of subjecting the double pipe to a heat treatment and then to a gradual cooling treatment to join and tightly fit the inner pipe and the outer pipe integrally to each other, thereby providing at least the inner surface of the inner pipe with a compressive residual stress. The resistance to high inner pressure can be improved and destructive strength, in particular, fatigue resistance to the repeated inner pressure can remarkably be improved.

Abstract: A process for brazing non-ferritic steel surfaces such as nickel chromium or stainless steel to which a suitable brazing alloy such as copper has been mechanically attached which includes the steps of instantaneously elevating the surface of the stainless steel to a brazing temperature while maintaining the material in a humidified gaseous atmosphere consisting essentially of a non-reactive carrier gas and a reactive gas present in sufficient concentrations to achieve fluxing; maintaining the surface temperature of the steel for an interval sufficient to permit fusion between the selected metal and the non-ferritic steel surface; after metal fusion has been achieved, allowing the resulting fused metal material to cool to a first lowered temperature in a controlled non-oxidative atmosphere at a rate which retards the formation of fine-grained steel crystals in the metal; and after reaching a metallurgical transformation point, rapidly cooling the fused metal in a controlled atmosphere to a temperature below wh

Abstract: A roll stamper for continuously preparing a substrate used for optical recording mediums, having a convexity and concavity preformat pattern, is prepared by a process comprising the steps of forming a low-melting metal layer on a roll substrate, and forming an auxiliary layer comprising a material different from that of a stamper, on the back of the stamper having on its surface a pattern corresponding with a convexity and concavity preformat pattern. The stamper is overlaid on the roll substrate in such a manner that the low-melting metal layer comes into contact with the auxiliary layer, and thereafter the low-melting metal layer is melted so that the stamper is fixed to the roll substrate.

Abstract: An elongated flexible tube that constitutes an insert part of an endoscope. The flexible tube comprises: a spiral tube made of a precipitation hardening metal and having a groove which is recessed inwardly from the outer surface of the tube, the groove extending in a straight line along the axis of the tube, the spiral tube being subjected to age hardening process after a solid solution treatment; a braided-wire tube formed by weaving fine metal wires into a braid, the braided-wire tube being closely fitted over the outer surface of the spiral tube; and a flexible skin closely and watertightly fitted over the outer surface of the braided-wire tube.

Abstract: The present invention relates to a method of manufacturing a clad bar and is basically characterized in that a columnar core member is fitted in a cylindrical outside layer member and the resulting assembly is heated, and then the heated assembly is rolled by a rotary mill provided with three or more cone type rolls to integrate the core member and the outside layer member by diffusion bending. The method is additionally characterized in that, in order to prevent unnecessary substances, such as oxides, from being formed on an interface between the core member and the outside layer member, the assembly is sealed at both ends thereof under reduced pressure or under vacuum or the assembly is cold drawn, the assembly thus welded or cold drawn is then heated and subsequently rolled by a rotary mill. Thus, an intermetallic compound layer formed between the core member and the outside layer member can be thinned, whereby improving bond strength.

Abstract: A method of cladding the ends of a length of previously clad pipe with a clad of greater thickness than the clad for the balance of the length in order to allow for threading, including the steps of boring, facing and turning the end of the pipe, plating by electroless deposition the faying surfaces of a nickel-base alloy cladding cylinder, assembling the cylinder to the length of pipe, assembling a close fitting tooling mandrel on the inside of the cladding cylinders, the tooling mandrel being made of a metal possessing a higher coefficient of thermal expansion than does the pipe, placing the subassembly within a housing having an induction coil therein, evacuating the housing atmosphere and back filling with an inert gas such as argon, heating the subassembly to about 1650.degree. to 2100.degree. F.

Abstract: The strengthening and stiffening of long, curved or tapered tubes is achieved by using internal strengtheners. The strengthening element conforms to the internal shape of the tube as it is inserted into the tube. The parts of the strengthening element which are then in contact with the inside of the tube have pre-formed welding material attached to them; a solid connection between the strengthener and the tube is achieved by selective heating, welding or by blowing adhesive material through the tube.If a tube has the non-welded strengthener in place, the forming or bending of the tube may proceed, since the strengthener takes the form of the tube at any stage of forming. The process is especially suitable for tubes with different cross-sections along their length.

Abstract: A method of manufacturing an externally clad tubular product employing a tubular host such as steel, including the steps of plating the external surface of the tubular host with a low melting point bonding metal alloy, assembling a tubular clad member, such as of nickel base alloy, over the plated tubular host, circumferentially welding one end of the cladding member to one end of the host member and welding the other ends in such a manner as to incorporate a metallic gas reservoir, thus forming a subassembly. The annular space formed in the subassembly between the interior of the cladding member and the exterior of the tubular host is evacuated of water vapor and oxygen. The evacuated subassembly is heated to about 1650.degree. to 2100.degree. F. thereby melting the bonding metal alloy, and the heated subassembly hot rolled to metallically bond the cladding member to the tubular host by means of the mechanism of liquid interface diffusion bonding.

Abstract: A rotor-shaft assembly which includes a ceramic, solid hubbed turbine rotor having an integral stub shaft brazed within one end of a generally cylindrically shaped sleeve member. A metal shaft is either brazed or cold press fitted within the other end of the sleeve member in a torque transmitting relationship. The stub shaft is formed with an annular relief therearound in order to reduce the compressive forces acting on the stub shaft by the sleeve member.

Abstract: A method of manufacturing an externally clad tubular product employing a tubular host such as steel, including the steps of plating the external surface of the tubular host with a low melting point bonding metal alloy, assembling a tubular clad member, such as a nickel base alloy, over the plated tubular host, circumferentially welding one end of the cladding member to one end of the host member and welding the other ends in such a manner as to incorporate a metallic gas reservoir, thus forming a subassembly. The annular space formed in the subassembly between the interior of the cladding member and the exterior of the tubular host is evacuated of water vapor and oxygen. The evacuated subassembly is heated to about 1650.degree. to 2100.degree. F. thereby melting the bonding metal alloy, and the heated subassembly hot rolled to metallically bond the cladding member to the tubular host by means of the mechanism of liquid interface diffusion bonding.

Abstract: A method of manufacturing an internally clad tubular product employing a tubular host such as steel, including the steps of plating the internal surface of the tubular host with a low melting point bonding metal alloy, inserting a tubular cladding member, such as of nickel base alloy, into the plated tubular host, circumferentially welding one end of the cladding member to one end of the host member directly and welding the other ends in such a manner as to incorporate a metallic gas reservoir, thus forming a subassembly, evacuating the annular space formed in the subassembly between the exterior of the cladding member and the interior of the tubular host of water vapor and oxygen, assembling a close-fitting full-length tooling mandrel of high thermal expansion material inside the subassembly, heating the subassembly to about 1650.degree. to 2100.degree. F.

Abstract: This invention relates to a tool with at least one wear-resistant hard metal part which serves to process production pieces, stones, or the like, wherein the hard metal part is firmly connected with a metallic carrier by solder located in at least one solder aperture. In order to reduce the danger of formation of tension cracks in the hard metal part, the invention provides that at least one predetermined weak point is created in the solder aperture.

Abstract: A joint for joining a ceramic shaft to a metal sleeve includes a gap separating the outer surface of the ceramic shaft from the inner surface of an overlapping portion of a metal sleeve. A brazing filler material is provided in only the portion of the gap proximate the end of the ceramic shaft to accommodate stresses caused by the different thermal characteristics of the metal sleeve and the ceramic shaft.

Abstract: A double-wall tube for a heat exchanger and method for producing same, the tube being formed by two tubular walls (1, 2) mounted one inside the other with a very small clearance (3)and then made to have a tight fit therebetween, the outer surface of the inner wall (2) and the inner surface of the outer wall (1) being interconnected by a thin layer of brazing metal in regions (4) which are discontinuous both in the circumferential direction and in the longitudinal direction of the tube. The brazed regions (4) represent 5 to 15% of the confronting surfaces of the inner wall (2) and outer wall (1) of the tube. The invention is in particular applicable to steam generators of fast neutron nuclear reactors.

Abstract: An earth boring drag bit is shown having polycrystalline diamond cutters mounted in cavities within the body thereof in a manner that, at the juncture of the dissimilar geometry of the cutters and the body, defines voids adjacent the cutters. These voids are filled with a powder tungsten carbide material to a level sufficient to eliminate the voids and is retained therein by a braze material infiltrated into the powder metal, thereby defining a wear-resistant continuous surface immediately adjacent the cutter element.

Abstract: This invention relates to a tool with at least one wear-resistant hard metal part which serves to process production pieces, stones, or the like, wherein the hard metal part is firmly connected with a metallic carrier by solder located in at least one solder aperture. In order to reduce the danger of formation of tension cracks in the hard metal part, the invention provides that at least one predetermined weak point is created in the solder aperture.

Abstract: A method of fabricating a fiber-reinforced metal matrix composite including the steps of mounting of a braided fiber tube on a substrate, wrapping a braze foil about the braided fiber tube to form an assembly that is encapsulated by a metal capsule which is creep collapsed onto the assembly at a temperature below the braze foil flowpoint. The encapsulated assembly is subsequently heated to a temperature sufficient to induce flow of the braze foil alloy and later cooled to allow solidification and annealing of the resulting fiber reinforced metal composite.

Abstract: A process for brazing a sleeve within a tube which is resistant to longitudinal expansion is disclosed herein. In the first step of the process, a thermally induced radial expansion is induced in the tube in a first longitudinal section of the tube which does not include the ring of brazing alloy which circumscribes the sleeve. In the second step of the process, a brazing heat is applied across the longitudinal section of the tube which does include this ring of brazing material. The residual tensile stress created by the thermally induced radial expansion in the tube avoids the creation of gaps in the braze joint between the sleeve and the inner walls of the tube. This process is particularly useful in creating high-quality braze joints in sleeving operations in nuclear steam generators, where the heat exchange tubes which need to be sleeved may be partially or completely prevented from expanding in the longitudinal direction due to sludge deposits in the generator.

Abstract: A method of manufacturing an internally clad tubular product employing a tubular host such as steel, including the steps of plating the internal surface of the tubular host with a low melting point bonding metal alloy, inserting a tubular clad member, such as of nickel base alloy, into the plated tubular host, circumferentially welding one end of the cladding member to one end of the host member directly and welding the other ends in such a manner as to incorporate a metallic gas reservoir, thus forming a subassembly, evacuating the annular space formed in the subassembly between the exterior of the cladding member and the interior of the tubular host of water vapor and oxygen, heating the subassembly to about 1650.degree. to 2000.degree. F. thereby melting the bonding metal alloy, and hot rolling the heated subassembly to metallically bond the cladding member to the tubular host by means of the mechanism of liquid interface diffusion bonding.

Abstract: The invention comprises a method of mounting a cutter, having a stud portion defining one end thereof and a cutting formation generally adjacent the other end, in a pocket in a drill bit body member. The method includes the steps of forming a channel extending into the pocket, inserting brazing material into the channel, inserting the stud portion of the cutter assembly into the pocket, then heating the bit body member to cause the brazing material to flow through the channel into the pocket, and finally re-cooling the bit body member. During the assembly of the various pieces required in the steps mentioned immediately above, a spring is used, cooperative between the cutter and the bit body member, to retain the stud portion in the pocket and also to displace the stud portion toward the trailing side of the pocket.

Abstract: A laminated, cylindrical, metal screen or molding element for vacuum perforation of plastic film or sheets, comprising two or more relatively thin cylindrical metal screens, each having a predetermined inside and outside diameter and each having a plurality of openings or holes therein of a predetermined size and geometrical shape, and said relatively thin screens stacked and bonded together, diametrically one inside the other thereby providing a screen of a desired thickness and a desired hole geometry wherein the holes in the screen have substantially straight walls perpendicular to the surface of the screen. A method of producing a relatively thick cylindrical metal screen for vacuum perforation of plastic film or sheets wherein the holes or openings in the screen have substantially straight walls perpendicular to the surface of the screen, comprising stacking and bonding together two or more matched relatively thin metal screens diametrically one inside the other.

Abstract: In order to produce a double-wall composite metal pipe, a pipe assembly, made up of an outer pipe of carbon steel and an inner pipe of stainless steel inserted in the outer pipe with an annular clearance therebetween is caused to advance relative to a plastic working device such as die or a series of rollers. Before the pipe assembly is caused to pass through the plastic working device, the outer pipe is heated to cause it to expand thereby increasing the annular clearance between the inner and outer pipes and establishing a temperature difference between the outer and inner pipes. The heated outer pipe is constricted by device of the plastic working means and caused to plastically contract against the outer surface of the inner pipe, while the inner pipe is subjected to expanding force of a mandrel inserted in the inner pipe, the mandrel backing up the pipe assembly from within the inner pipe against the constricting action of the plastic working device.

Abstract: A laminated, cylindrical, metal screen or molding element for vacuum perforation of plastic film or sheets, comprising two or more relatively thin cylindrical metal screens, each having a predetermined inside and outside diameter and each having a plurality of openings or holes therein of a predetermined size and geometrical shape, and said relatively thin screens stacked and bonded together, diametrically one inside the other thereby providing a screen of a desired thickness and a desired hole geometry wherein the holes in the screen have substantially straight walls perpendicular to the surface of the screen.A method of producing a relatively thick cylindrical metal screen for vacuum perforation of plastic film or sheets wherein the holes or openings in the screen have substantially straight walls perpendicular to the surface of the screen, comprising stacking and bonding together two or more matched relatively thin metal screens diametrically one inside the other.

Abstract: In the installation, a strip is shaped from a split tube which is welded or seamed to give a closed tube in a welding or seaming station. Associated with the welding or seaming station is a suction mechanism used for the removal of on the one hand the cold air flow produced by the moving open tube and on the other the air flow heated during welding and flowing back from the closed tube, as a result of the reduction of the internal cross-section thereof. This obviates air turbulence in the welding or seaming station, which could whirl up the pulverulent material introduced into the open tube in a dosing station and could be deposited on the longitudinal edges of the split tube. This could unfavorably influence the seaming or welding process.

Abstract: A method of manufacturing bimetallic tubes is disclosed. In this method, after an inner tube is inserted into an outer tube, the resulting tube assembly is heated, while pressurizing the inside of the inner tube with a gas, in the presence or absence of a solder material. When using no solder material, the materials of the inner and outer tubes are so selected that a thermal expansion coefficient of the inner tube is smaller than that of the outer tube.

Abstract: A radiant heat shield for use in a superconducting generator is described which is formed by brazing an inner and an outer tube together. The inner tube has a plurality of coolant channels machined in its outer cylindrical surface. The brazing operation consists of applying a brazing compound to the outer cylindrical surface of the inner tube prior to cold working the two tubes together, followed by a heating to a temperature in excess of the melting point of the brazing compound.

Abstract: A hermetic seal for an optical fiber is fabricated by casting or molding a mass of fusible alloy around the fiber so that the alloy solidifies within a confined space. The alloy used is characterized by low thermal coefficient of expansion, minimal relaxation after solidification, and appreciable expansion as it solidifies, thereby to create a stable pressure contact at its interface with the optical fiber. The solidified mass may be subsequently soldered into a passage through a wall of a fiber optic device package. Alternatively, the mold within which the mass of alloy is encased or molded may, itself, be soldered into the passage.