Abstract: A hydroformable frame element is formed from the combination of at least two elements. The at least two elements are designed with a partially overlapping region, with an annular space defined within the overlapping region. The annular space is filled with adhesive, which is then cured to bond the at least two elements together. The adhesive bond is designed to withstand the stresses caused by the hydroforming operation and to retain its strength so that the hydroformed article is then usable as a vehicular frame element.

Abstract: A structure (10) in the shape of an aerodynamic panel in which adjacent cells (20a, 20b) are formed by placing a stack of three metal plates in a mold. After diffusion welding of the plates at the required locations, a first variable pressure is applied in a first series of cells (20a) formed between the outer plate and the intermediate plate and a second independent pressure approximately constant and lower than the first is applied in the other cells (20b) and on the inner face of the stack. Thus, this partially forms the cells and shapes the structure in contact with a complementary surface of the mold. The final conformation of the cells and the structure is obtained by applying a second pressure cycle in the cells and on the inner face of the stack.

Abstract: A method of forming a tubular member with at least one flange includes the steps of providing a tubular member, expanding at least one portion of the tubular member, and positioning the tubular member between open die halves. The method includes the steps of applying at least nominal internal hydraulic pressure to the tubular member. The method further includes the steps of progressively closing the die halves to progressively deform the tubular member and progressively expel the at least one portion of the tubular member to define a flange comprised of wall portions of the tubular member engaging one another. The method includes the steps of increasing the hydraulic pressure to expand and conform the tubular member. The method also includes the steps of separating the die halves and removing the tubular member having a flange from the die.

Abstract: Hydroforming apparatus is provided with retractable part locators that are adapted when extended to receive and hold end portions of a tubular part to be hydroformed and thereby support and hold the part between the hydroforming dies when the dies are open. Seal units mounted on separate elevators have a retractable seal carrier and the seal carriers are adapted when the seal units are elevated to advance and initially engage the respective tubular part end portions while the part is being so held. The part locators are adapted to release the end portions of the part and retract out of the way of the seal carriers to permit the seal carriers to then further advance on the respective end potions of the part to a position closely adjacent the end faces of the dies while also centering the part lengthwise with respective to the dies prior to die closure.

Abstract: A method of making a gas tank includes hydroforming two halves and welding the halves together. Two types of welds are used in welding the two halves together, tack welds for holding the two halves together, and stitch welds to complete the welding of the two halves. Additional steps are taken prior to the finishing stitch welds. Reinforcement is added where necessary. Double tanks, for both gasoline and oil, are also fabricated by essentially the same method steps.

Abstract: A sheet hydroforming method is disclosed wherein two stacked metallic sheets are clamped between a pair of upper and lower dies 10, 11 and a fluid is introduced and pressurized between mating surfaces of the metallic sheets, causing the metallic sheets to bulge into a space defined by die cavities 10b and 11b. A thru-hole 11d for introducing the fluid is formed in one of the dies so as to lead to a holding surface of the die, while a pierced hole for introducing the fluid is formed in one of the metallic sheets in a portion of the one metallic sheet which portion is in contact with a holding surface 10a (10b) of one of the dies, the pierced hole being positioned with the thru-hole 11d, then the fluid is introduced in a pressurized state between mating surfaces of the metallic sheets from the thru-hole through the pierced hole, thereby causing the metallic sheets to bulge. According to this method, a pressurized fluid can be introduced between the mating surfaces of blanks easily without leakage of the fluid.

Abstract: Apertures in airfoils for use in a hot gas path of a turbine are formed from the interior of the airfoil to the exterior in circumstances where line-of-sight access from locations external to the nozzle is inhibited or prohibited. A water jet nozzle head is disposed in a cavity within the airfoil and angled at the desired inclination to cut an angled hole through the airfoil wall using a water jet and abrasive material contained in the water. A protective device, e.g., a backstop or shield, is provided on the outside of the nozzle to prevent damage to other portions of the nozzle from the water jet which would otherwise impinge but for the protective device.

Abstract: A sheet metal formed thereon with a number of spaced projections, wherein the projections are formed by the steps of positioning the sheet metal between a female die formed with a number of spaced recesses at one surface thereof and a male die formed with a concavity to be coupled with the female die and a number of spaced projections located at the bottom of the concavity to correspond with the recesses of the female die and pressing the sheet metal under existence of hydraulic fluid between the sheet metal and the concavity of the male die.

Abstract: An axle assembly is provided that includes a tubular member having an outer wall and an interior cavity. The other wall includes a first interlocking feature. An axle component mounting member, such as a bearing shoulder sleeve and/or a brake flange, is arranged on a portion of the outer wall. The mounting member includes a second interlocking feature coacting with the first interlocking feature to affix the mounting member and tubular member to one anther. The axle assembly may be formed by arranging the axle mounting member into a die assembly. A tubular member may be arranged in the die assembly within an opening in the mounting member. A hydroforming process may be employed to pressurize a cavity within the tubular member. A portion of the tubular member is deformed into engagement with the mounting member to affix the mounting member to the tubular member.

Abstract: A method of making a tube having an expanded region which includes the steps of providing an elongated metal tube, preparing the tube to be expanded, and, exerting a generally uniform outwardly radial force to create the expanded region. During the preparation step, a region of the tube is annealed by applying heat. The outward radial force may be created by pressurizing the tube, by freezing water within the tube or by axially rotating the tube.

Abstract: The present invention is for a method of lap joining two tubular members and then hydroforming the tubular assembly. An insert end of the first tubular member is inserted into a receiver end of the second tubular member to form a lap joint. A filler metal ring is placed about the outer periphery of the insert end so that it is adjacent the opening of the receiver end of the second tubular member. Heat is applied to braze or solder the lap joint, forming a tubular assembly. The tubular assembly is then hydroformed during which time a supplementary mechanical lock may be formed in the lap joint.

Abstract: A cup shaped yoke made of sheet material has an opening portion provided in a side wall on an axial end side, a shoulder portion provided in the sidewall on another axial end side, a magnet installation portion for installing a magnet, which is provided in the side wall between the opening and shoulder portions and whose wall thickness is substantially equal to thickness of the sheet material, and a bottom portion, which is provided in a bottom wall, having a boss shaped bearing accommodating portion in a center thereof. Each wall thickness of the opening, shoulder and bottom portions including the boss shaped bearing accommodating portion is equal to or smaller than a half of wall thickness of the magnet installation portion.

Abstract: A method of fabricating a driveline assembly including the steps of inserting a first member within a second member, heating the first member to a temperature greater than that of the second member and inserting both members into a die. The inner surface of the die includes an interlocking torque transferring profile. Fluid pressure is applied to the inner diameter of the inner member to expand both members into the profile on the inner surface of the die. The inner and outer members are then removed from the die and cooled such that both members are at a common temperature. Because the inner member was at an elevated temperature, and thereby expanded a greater amount than the outer member, cooling of the members results in a clearance between the members that provides for relative axial movement between the inner and outer members.

Abstract: The invention relates to a method for making a shaft/hub connection. For this purpose, a toothed or splined shaft having an external toothing is pushed with clearance into an internal toothing of a hub, tooth to space, and the external toothing of the shaft is pressed together with the internal toothing of the hub. In order to make it possible in a simple reproducible way to make a shaft/hub connection which optimally satisfies the requirements of dynamic loads, it is proposed that, in the push-in position of the shaft, the latter is deformed plastically out of a cavity of the shaft in a radial circumferential widening operation and, so as to provide freedom from clearance between the spaces of the external toothing of the shaft and the internal toothing of the hub, the said internal toothing engaging into the said external toothing, is pressed against the hub in such a way that the hub is deformed elastically and a press fit between the shaft and the hub is produced.

Abstract: A golf club shaft, set of shafts, or golf clubs having shafts which have been produced by a process that includes a hydroforming step. By utilizing a hydroforming step, a metal or metal matrix composite golf club shaft can be formed into a variety of configurations or shapes heretofore not possible and can include hydroformed ornamental design features. The hydroformed shafts offer enhanced club feel and/or performance.

Abstract: A method for fabricating a thin metal shell that has connecting components is disclosed. This method comprises the following steps: forming a metal plate by plastic forming technologies into a thin shell with a plurality of bonding bases thereon; applying a structure adhesive on the bonding bases; disposing connecting components on the bonding bases with the structural adhesive; and curing the structural adhesive which bonds the shell and connecting components.

Abstract: A method of forming clad piping or tubing includes the steps of providing a support billet, finished to a desired, predetermined dimension, having a cladding surface, and providing a CRA cladding material billet, similarly finished to a desired, predetermined dimension. The dimension of the CRA cladding material billet is predetermined such that the CRA cladding material fits onto a cladding surface of the support billet establishing an interface gap. Sealing the interface gap, evacuating the interface gap to form an assembly and Hot Iso-statically Pressing the assembly to metallurgically bond the CRA cladding material billet to the support billet to form a composite billet. The composite billet is extruded at high temperature to form the clad piping or tubing. The clad piping or tubing formed in also disclosed.

Abstract: In a method of making an exhaust gas collector, a collector housing is made from a tubular blank, and subsequently, an inlet duct is formed through a widening process to provide a substantially rectangular cross section with rounded narrow sides. The inlet duct is provided with a head flange. At the outlet side, the collector housing is necked by a press-forming process so as to shape an outlet duct having a substantially circular cross section which is reduced in size compared to the cross section of the collector housing. Attached to the outlet duct is an end flange.

Abstract: A friction lining for use in the clutch plate of a friction clutch or a multiple wrap brake band for use in an automatic transmission is obtained by adhesively securing one side of a friction generating second layer to one side of a metallic first layer. The necessary incisions in the form of cuts, slots or slits are made from the exposed side of the second layer in a direction toward the exposed side of the first layer by resorting to one or more high-energy streams, such as laser beams, electron beams or liquid jets. Each incision can be made in one or more stages by a single stream or by a series of successively applied streams.

Abstract: In attempting to reduce deformity when joining vehicle frame components, a riveting/brazing process has been proposed. This process includes joining tubular members, such as hydroformed parts, by cutting at least one flange into one end of a first body member, shaped in conformance with the surface of a second body member. Location holes are formed into each flange as well as into the surface of the second member in suitable alignment with each other. A brazing filler material is fixed into a side of the flange, usually within a pocket, intending to lie on the surface of the second member when the two structures are attached. The flange(s) are initially attached to the surface of the second member by means of a rivet to formed an actual vehicle body assembly. Heat is then applied to the assembly to form a brazed T-joint.

Abstract: A large dimension hollow body such as a fuel tank is formed from cold deformable sheet metal by cutting a sheet metal blank of a conformation matching the hollow structure to be formed and which has a nonuniform cross section between its ends. The sheet metal blank is then formed into a three-dimensional shape closed at one end and subjected to hydrostatic forming, whereupon the other end is closed optionally after insertion of an object to be received in the tank such as a fuel pump. The welding of the edges of the blank together and the application of the caps can produce pressure-tight weld seams and can be effected by laser-beam welding or tungsten inert gas welding.

Abstract: A vehicle frame assembly includes a first vehicle frame component that is formed by deforming a closed channel structural member to have a relatively small end portion and a relatively large end portion. A member is provided having first and second ends. The relatively large end portion of the closed channel structural member is secured to the first end portion of the member to form the first vehicle frame component. A plurality of second vehicle frame components are provided. The first vehicle frame component and the plurality of second vehicle frame components are secured together to form the vehicle frame assembly.

Abstract: A method for forming an article having a wall that is at least partially fabricated from tubing. The methodology employs a pressurized fluid to deform the tubing such that an outer surface of the tubing substantially conforms to a predetermined first wall configuration, an inner surface of the tubing substantially conforms to a predetermined second wall configuration and each of segment or loop of the tubing is substantially contiguous with at least one other segment or loop between the first and second surfaces.

Abstract: Superplastic forming tools and method in which pairs of stacked metal blanks are serially loaded between heated forming dies that are moved to a closed position on each of the pair of blanks so that a partial perimeter gas seal is established therebetween. A pressure wedge is then introduced between the two blanks along one edge of the pair to act as a stopper or air seal to complete perimeter sealing thereof. The pressure wedge also establishes the operative position of a gas injection port, which directs pressurized air interiorly of the completed perimeter seal of the pair of blanks to force the blanks in opposite direction for the superplastic forming of a pair of discrete parts. The wedge and forming dies are then opened for the removal of a pair of formed parts and for the subsequent loading of additional pairs of stacked sheets for their simultaneous superplastic forming into pairs of parts.

Abstract: A method is disclosed for forming a hem flange in an aluminum alloy sheet during the forming of the sheet into a panel that is intended to be attached to a second panel by hemming. The hem flange is formed by fluid pressure over a small radius tool portion to bend the flange from the sheet material and stretch the flange material below the bend to form a thinned hemline valley in the material. The original bend and thinned valley cooperate during the folding of the flange around the second panel to form a flat pinched hem without cracking or fracturing the flange material.

Abstract: A method for fabricating an Invar tool includes the step of superplastically forming an Invar facesheet for the tool. A tool header is provided, and the Invar facesheet is then formed with an SPF diaphragm driver to match the predetermined contour of the tool header. The Invar facesheet is then welded to the tool header. Forming the Invar facesheet is achieved by positioning the Invar facesheet between a superplastically formable diaphragm and a die having the predetermined contour. The diaphragm is heated to a predetermined superplastic temperature, and a predetermined pressure is applied to the diaphragm. Application of the predetermined pressure allows the diaphragm to cause the Invar facesheet to form against the predetermined contour of the die. Superplastically forming the Invar facesheet results in a negligible amount of excess scrap, reduces material costs, and reduces labor costs.

Abstract: Hydroforming apparatus includes in-die hydropiercing apparatus with easy and precise adjustment of the positioning of a backup plunger that is received in a die button and is positioned in a hydroforming position, a prepiercing position, a piercing position, and a slug ejecting position that may be outside the plunger or may be the hydroforming position. Wherein the plunger is required to be precisely positioned and held in the prepiercing position in the die button in order to obtain a desired prepiercing action without prematurely piercing the hydroformed part. The in-die hydropiercing apparatus has a plunger actuating hydraulic cylinder that moves the plunger to the different positions and a cam actuating hydraulic cylinder that positions a cam in determining the prepiercing position of the plunger.

Abstract: A reinforced hydroform member having an outer structural member reinforced by a structural foam supported by the outer structural member. The structural foam extends along at least a portion of the length of the outer structural member. The structural foam is a heat-activated epoxy-based resin. As the foam is heated, it expands and adheres to adjacent surfaces. The preferred structural foam material is commercially available from L&L Products of Romeo, Michigan under the designation L5206, L5207, L5208, or L5209.

Abstract: A hydroforming assembly has a plurality of die structures that are mounted on a press for reciprocating movement between open and closed conditions. The die structures have cooperating die surfaces defining a die cavity when in the closed condition and receive a metallic tube blank when in the open conditions. A hydroforming fluid supply system has tube-end engaging structures that are movable to selectively and sealingly engage opposite ends of the tube blank. The hydroforming fluid supply system provides pressurized fluid into an interior of the tube blank in order to expand the tube blank outwardly into conformity with the die cavity. A punch extends within a passage of at least one of the die structures. The punch is movable between retracted and extended positions. A punch driving assembly drives the punch between the retracted and extended positions to punch a hole into the expanded tube blank.

Abstract: The invention relates to a method and apparatus for the production of double-walled hollow sections by means of internal high-pressure forming, a first hollow section being inserted into a second hollow section, after which the double-walled hollow section thus formed is subjected to high internal fluid pressure in such a way in an internal high-pressure forming die that the double-walled hollow section is expanded. During this process, an air gap is formed between the first, inner, hollow section and the second, outer, hollow section.

Abstract: A method is disclosed for inserting an end of a first tubular member into a complementary end of a second tubular member and attaching (e.g., welding) the adjacent surfaces of the inserted ends in a tight peripheral bond. In the method, a substantially continuous protrusion is formed in either the first or second member. Thereafter, the first and second tubular members are placed relative to each other such that a current may be passed through the protrusion and a seal may be formed, thereby joining the members.

Abstract: A fuel rail formed by hydroforming. The hydroforming process includes applying a seal onto a fuel tube, and installing fuel injector blocks, including fuel injector ports, onto the tube in desired positions. The fuel tube assembly is placed in a die assembly, and pressurized fluid is supplied to the interior of the tube. The pressurized fluid causes the tube to expand outwardly into engagement with the blocks, and to pierce holes through the tube within each of the blocks to provide fluid communication with the associated fuel injector and other ports.

Abstract: A plate material is drawn to form a first-drawing product in the shape of an elliptically cylindrical container having an elliptical cross section. Then, the first-drawing product is drawn to form a re-drawing product in the shape of a generally circular cylindrical container. Next, the re-drawing product is drawn to form a late-drawing product in the shape of an elliptically cylindrical container having an elliptical cross section in which a major axis and a minor axis of the elliptical cross section are reversed with respect to a major axis and a minor axis of the elliptical cross section of the first-drawing product. Thereafter, the late-drawing product is drawn to form a final product as a yoke.

Abstract: A method of making combustion turbine transition duct bodies without longitudinal welds by hydroforming at least one in a hydroforming press. Ideally, two transition duct bodies can be made simultaneously with their exit ducts joined together, which can be cut after hydroforming. Apparatus for hydroforming transition ducts includes axial compression members and pressure intensifiers to impart highly detailed features into the work piece.

Abstract: The seal units that form part of a hydroforming apparatus that further includes dies for hydroforming parts are each provided with a tubular part locator for locating and clamping a tubular part in alignment with the seal unit. The part locator basically comprises a locator member, a pair of pivot arms and a backup member wherein the locator member and the pivot arms together with the seal unit are supported by an elevator that aligns the seal unit and the locator member with the hydroforming dies when the latter close on the tubular part. The locator member has a concave surface and guide surfaces wherein the concave surface has a shape conforming to the outer surface of the part and the guide surfaces are adapted to guide an end portion of the tubular part onto the concave surface of the locator member and thereby into alignment with the seal unit.

Abstract: The present invention is for a method of lap joining two tubular members and then hydroforming the tubular assembly. An insert end of the first tubular member is inserted into a receiver end of the second tubular member to form a lap joint. A filler metal ring is placed about the outer periphery of the insert end so that it is adjacent the opening of the receiver end of the second tubular member. Heat is applied to braze or solder the lap joint, forming a tubular assembly. The tubular assembly is then hydroformed during which time a supplementary mechanical lock may be formed in the lap joint.

Abstract: In a method and a device for producing a circumferentially closed hollow profile, a hollow-profile blank is expanded by fluidic internal high pressure in an internal high-pressure forming tool, after which the hollow-profile blank assumes the final shape of the hollow profile. In order to make it possible in a simple manner to have a production of a hollow profile in which process reliability is ensured to a sufficient extent even in the case of high expansions of the hollow profile (higher than or equal to the breaking elongation of the material), during expansion, the hollow-profile blank is supported, on at least one partial circumferential region, by at least one diaphragm fastened to the inside, facing the blank, of the tool and capable of being acted upon by a controllable pressure acting from outside, the diaphragm shifting back elastically as expansion progresses, with the supporting pressure acting on the diaphragm being reduced at the same time.

Abstract: The invention relates to a method and an arrangement in connection with a secondary coating line, in which method a fiber, fibers or fiber bundles are unwound from payoff reels (1) and guided to a press (4) by which a secondary sheath is formed around the fiber(s) or the fiber bundles and grease is fed into the secondary sheath, and in which method the assembly formed by the secondary sheath and the fiber(s) or the fiber bundles is pulled at a constant rate and low tension to a winding device (15) through cooling means (5, 6). In order to control the difference in length between the fibers and the secondary sheath, the difference in length between the fibers and the secondary sheath is arranged to be adjusted by adjusting fiber tension by moving the fixing point between the fibers and the secondary sheath along a straight part formed in the relaxation part by using wheel structures (8, 10).

Abstract: A tubular axle beam with variable wall thickness for a vehicle is provided including a first beam portion extending longitudinally between first ends and including spaced apart first longitudinal edges. A second beam portion extends longitudinally between second ends and includes spaced apart second longitudinal edges. Weld beads secure the first longitudinal edges to the second longitudinal edges to define a cavity between the beam portions with the first and second ends arranged adjacent to one another. Preferably, the tubular axle beam is constructed by stamping a first blank to form a first half of the beam, and a second blank is stamped to form a second half of the beam. The first and second portions are welded to one another to define a cavity between the portions. In another embodiment of the invention, a tubular axle beam includes a hollow beam extending longitudinally between opposing ends.

Abstract: The present invention provides a process for forming aluminum alloy hydroformed structures for automotive vehicles at low cost. The process continuously casts molten aluminum alloy into aluminum alloy strip material preferably followed by continuously warm rolling the strip material into aluminum alloy sheet material. The sheet material is formed into one or more aluminum alloy tubes and the tubes are hydroformed into the desired automotive vehicle structure.

Abstract: The present invention provides an apparatus and a method which use hydroforming to shape complex structures from materials such as sheet metal or composites. In particular, an apparatus and a method for shaping complex structures using composites such as continuous-fiber or woven fiber composites with limited wrinkling or rupture of the composite during the shaping process.

Abstract: A process for manufacturing fuel tanks by blast shaping of steel is described, preferably stainless steel and occasionally, another type of carbon steel, especially for the type of fuel tanks to be assembled in automobiles, with any simple or complex, reinforced shape and with a wall thicknesses permitting up to a 50% weight reduction with regard to conventional tanks. The process comprises the preparation of flat or not flat metallic pre-forms, with identical or different dimensions, able to be eventually subjected to pre-heating, in order to then be placed into a mold which has the impression which is desired to be transferred, and to be subjected to a blast shaping operation with the use of a suitable fluid (liquid, gas or mixture of both), with the eventual application of intermediate heating operations where applicable.

Abstract: A process and system for manufacturing a built-up camshaft by which the operational safety of the camshaft is ensured in a simple manner in any engine operation and the camshaft can arbitrarily be adapted to abutments which have different positions because of the individual engine construction. At least one cam is pushed onto a hollow shaft, after which the hollow shaft is expanded between the two faces of the cam which extend transversely with respect to the longitudinal course of the hollow shaft and at the respective bearing point by means of a highly pressurized pressure fluid. This fluid is delivered by a lance-shaped probe introduced into the hollow space of the shaft. On the one hand, a press fit occurs between the cam and the hollow shaft and, on the other hand, a bulging of the bearing point of the hollow shaft occurs which bridges the distance between the hollow shaft and the abutment.

Abstract: Process for producing a tubular component which comprises sections which are intentionally different from one another with regard to one or more aspects selected from the group consisting of aspects including material, thickness, size, more specifically circumference or diameter, and the like, and hydroforming of the component, in which process the component is produced by rolling up a substantially flat sheet, which flat sheet substantially corresponds to a flat blank of the tubular component.

Abstract: A method of hydroforming a reinforced tube comprising providing a metal tubular blank having an interior defined by an inner surface and an exterior defined by an outer surface. A metal reinforcing member is provided and inserted into the interior of the tubular blank. The reinforcing member is engaged with the inner surface of the tubular blank and is attached to the inner surface of the tubular blank. The tubular blank and reinforcing member welded thereto are placed into a hydroforming die having die surfaces defining a die cavity, and pressurized fluid is provided within the tubular blank so as to conform the tubular blank with the die surfaces of the die cavity.

Abstract: A method of manufacturing a gas turbine engine fan blade (10) comprises forming three metal workpieces (50,52,54). A metal slab (30) is upset forged at both ends (32,34) to produce a metal block (40) with increased thickness (42,44) extending from opposite surfaces (36,38). The metal block (40) is cut in an inclined path to form two of the metal workpieces (50,52). The metal workpieces (50,52,54) are assembled into a stack (56) so that the flat surfaces (38,42,46,48) are in mating abutment. Heat and pressure is applied across the thickness of the metal workpieces (50,52,54) to diffusion bond the metal workpieces (53,52,54) together to form an integral structure (100). The integral structure (100) is hot creep formed and superplastically formed to produce the required aerofoil shape and the thickened end is machined to form the blade root (26). The method enables thinner metallic workpieces with better microstructure to be used and increases the yield of metallic workpieces.

Abstract: An approach to restoring the cross-section of a bent tube to circularity. The tube is placed into a fixture, so that pressurization does not remove the bend. Liquid is placed into the tube, and pressurized. Pressure is increased until the wall of the tube undergoes plastic deformation, and becomes circular.

Abstract: An apparatus for forming a generally planar metal plate into a dish with a three-dimensional pattern is provided. The apparatus comprises a mold having a forming surface with a contour corresponding to said three-dimensional pattern, and having edges corresponding to boundaries of the dish, which edges are defined by side walls essentially perpendicular to the forming plane; a forming device comprising a fluid basin and pairs of electric discharge members within the fluid and having an opening facing the mold to allow transmission of a pressure wave from the fluid to the metal plate; and an electric discharge circuitry for discharging a short and intense electric current through the pairs of electric discharge members generating an electric spark or breakdown within the fluid to yield formation of plasma, vapor or both.

Abstract: A process is for producing a circumferentially closed hollow profile, which is of frustoconical form in sections, from a sheet-bar blank. To produce hollow profiles of this type, the sheet bar is cut to size so that a blank with a rectangular section and a ring segment, the summit of which adjoins the center of one side of the rectangle, while its outer arc, which faces the rectangle, is of approximately the same length as the length of the side of the rectangle, is formed, sheet-bar material also being left on the blank outside the summit, between the ring segment and the side of the rectangle, this material joining the ring segment with the side of the rectangle integrally at all locations and also joining the corners of ring segment and rectangle which are closest together, so as to form a rounded edge contour. Then the side edges of the blank are bent into abutment with one another about the longitudinal center axis of the blank.

Abstract: A multi-section support rail has a first section with an outer circumferential wall, a parallel inner circumferential wall and a transverse web extending longitudinally therealong, a second section hollow tubular section with an outer circumferential wall and a parallel inner circumferential wall. The outer circumferential walls are substantially identical dimensionally. The sections are joined at mating surfaces,. The joined sections are pre-bent at the second section and then hydroformed to a final desired shape. The transverse web retains the extruded dimensions throughout the hydroforming process.