Abstract: In order to prevent a probe (2) used for expanding tubes (1) in portions from having an uneven effect due to its eccentric position in a tube which is not completely straight, the probe given a slightly flexible design is provided with centering rings (11, 13) which flexibly rest on both the inner face of the tube and on the probe member. The flexible parts (7) of seals limiting the operational regions (8), along their circumference, then evenly and simultaneously contact the inner wall of the tube. Several designs for the centering rings are possible. To facilitate their introduction into the tube, the process of introduction is accompanied by a process of lubricating the inner tube parts, a process which improves sliding and for which the hydraulic fluid required in any case may be used.

Abstract: A method for forming projections on the periphery of a pipe in order to provide branch pipes, such as a manifold for automobiles, is characterized in that the branch pipes are formed by a bulging process to have a predetermined thickness without thinning. A first embodiment includes the step of indenting a pipe member by press work or the like, at locations close to the position of a projection which is to be formed, in a preliminary deforming process. The deformed pipe member is then placed in a bulge mold having a recess or space, with the pipe member being positioned so that the indentations in the pipe member lie adjacent the recess in the bulge mold. Pressurized fluid is then introduced into the interior of the pipe member to bulge the wall of the pipe member into the recess in the bulge mold. A second embodiment employs a bulge mold having fixed recesses or spaces and variable recesses or spaces for forming a plurality of projections.

Abstract: In a method of explosively expanding a tubular metal component into engagement with a surrounding metal component, an explosive charge is disposed axially and fired in an insert having a hollow cylindrical container fitting closely within the portion of the tubular metal component to be expanded and having charge holding device, for example an axial pocket, to accommodate the explosive charge, the container being filled with a shock wave-transmitting liquid. Compared with solid inserts, the novel hollow insert is cheaper and requires a smaller explosive charge for a given operation. The method is especially advantageous for expanding large diameter tubes.

Abstract: A method for forming branch pipes on the periphery of a pipe, such as a manifold for automobiles, is characterized in that the branch pipes are formed by a bulging process to have a predetermined thickness without thinning. A first embodiment includes the step of indenting a pipe member by press work or the like, at locations close to the position of a projection, in a preliminary deforming process. A second embodiment employs a bulge mold having fixed spaces and variable spaces for forming a plurality of projections. The second embodiment includes the step of bulging the pipe material into the fixed spaces while the variable spaces are occupied by detachable members, and the step of removing the detachable members from the mold and then bulging the pipe member again.

Abstract: A forming tool including a mandrel having nuts threaded on its exterior at both ends with an outer cylindrical surface between the nuts, a forming assembly positioned around said mandrel between said nuts, the forming assembly including a pair of end rings having inner lips extending axially along said outer cylindrical surface and an overhang with a re-entrant recess between the joining of the lip with the remainder of the end ring, a resilient sleeve having its ends bonded within said re-entrant recesses of said end rings and extending in surrounding relationship to said cylindrical mandrel surface, means surrounding each end of said sleeve adjacent said end rings to prevent extrusion of the material of said sleeve, seals for sealing between the exterior of said mandrel and the interior of said end ring lips, and means for supplying pressure to the interior of said sleeve to move it radially outward with sufficient force to form a member surrounding the tool outward.

Abstract: An apparatus for securing straight tubes between two tube sheets in a pressure-tight manner, especially in the manufacture of heat exchangers. Tubes are inserted, with play, in bores of the tube sheets. One end of each tube is hydraulically expanded via a pressure medium to thereby press this one end against the associated tube sheet. The one end is secured to the associated tube sheet, preferably by being welded thereto. Each tube is heated in conformity with a prescribed prestress that is to be produced in secured ones of the tube to take into account subsequent operation conditions to push a portion of the non-secured other end of the tube out of its associated tube sheet until a predetermined difference in length between the cold and heated-up states of the tube is pushed out.

Abstract: An improved cold forging tool to exert radial forces outwardly to form a tubular member outwardly into an annular member which includes a central body having external recesses and external shoulders at each end, a resilient sleeve surrounding said central body and having its ends positioned within said external recesses, a passage through the central body to communicate between a pressure supply line connected to the end of the body and the interior of said resilient sleeve, and first and second dual segmented, expandable anti-extrusion ring positioned between the central expansion portion of said resilient sleeve and each of said shoulders, a resilient ring retaining each of said segmented rings in surrounding relationship to the ends of said resilient sleeve to prevent extrusion of the resilient sleeve during the forming of the tubular member and a shoulder on said body limiting the radial outward movement of the rings abutting the external body shoulders.

Abstract: A method and apparatus for hydraulically forming metallic tubular bodies are disclosed. A forming die is provided, with the interior of the die configured to receive the tubular body to be shaped. The tubular body is filled with liquid, preferably water, with the interior of the tubular body then sealed. A forming plunger is thereafter inserted into the tubular body whereby localized hydraulic pressurization of the liquid within the body is effected. Outward deformation of the body toward the interior of the forming die thus results, with the formation of tapers, steps, projections, or other desired features readily achieved. The present invention is particularly suited for forming the tubular components of musical instruments.

Abstract: A swaging mandrel is inserted in a tube confined by a tube sheet or other surrounding structure. A pair of seals define the axial limits of a hydraulic pressure zone within the tube sheet in which radial expansion of the tube takes place in response to fluid pressure. At one side of the tube sheet, an elastomeric ring can extend beyond the tube sheet and, in response to the fluid pressure, produce an attenuated radial expansion force that bulges the tube. At the primary side of the tube sheet, an elastomeric ring, in response to the fluid pressure, causes arcuate segments of a cylinder positioned beyond the tube sheet to expand radially and flare the tube at the opposite side of the tube sheet.

Abstract: An apparatus and method including a swaging die (10) with an internal cone-shaped bore section which will swage a pipe (14) forced into such die and form the cone section (30) on the pipe. Within the swaging die (10) is an insert/ejector plate (32) of a diameter to fit within the bore of the pipe (14) and wherein high pressure fluid directed through the insert/ejector plate (32) to the inside wall of the pipe (14) expands the pipe thus forming a longer, more acceptable, cone section (30) capable of providing more thread length for later threading operation. After the expansion pressure is relieved, the insert/ejector plate (32) is used to force the pipe (14) out of the swaging die (14).

Abstract: A driveshaft for a motor vehicle having a double tapered tubular body with its largest diameter near its midpoint and its least diameter adjacent its opposite ends. The body is substantially and continuously tapered from the midpoint to each of the ends. The tapered section of the tubular body has its outer surface positioned near a surface defined by a parabola revolved about the longitudinal axis of the body. The parabola has its apex at the midpoint of the driveshaft and intersects two points on the longitudinal axis at approximately the mounting planes where the driveshaft is supported at its ends. In addition, a method of manufacturing the tapered tubular body of the driveshaft includes a mold having a tapered wall section and cylindrical shaped end sections to receive the cylindrical tube. The cylindrical tube is able to receive varying lengths of elastomeric plugs which can be sequentially compressed to deform the tube outwardly to abut the tapered wall section of the mold.

Abstract: A method of forming a ridge in a cylindrical tube member comprises placing the ends of the tube member into spaced-apart dies so that each die is a close fit around the respective end of the tube member, and the tube member has a free portion between the ends. Liquid is supplied to the interior of the tube member and the liquid pressure within the tube is increased so that its free portion bulges radially outwardly. While the radial bulge of the free portion of the tube member is continuously measured on the outside, the liquid pressure is gradually increased depending on the radial bulge measured until a pre-determined radial bulge is measured. Thereafter, while the liquid pressure is maintained in the tube member, the dies are axially moved towards each other until they are spaced a pre-determined axial distance apart. During this displacement the dies deform the bulge until the desired ridge form is reached.

Abstract: A method of relieving residual stress in a metal pipe comprises the steps of applying, by using a pressure medium, a low pressure to an interior of the metal pipe placed in dies, and applying, while preventing the buckling, an axial compression load to the pipe so as to effect a uniform plastic deformation of the entire metal pipe while maintaining the desired shape of the pipe, thereby relieving the residual stress in the metal pipe.

Abstract: A system for forming a surface configuration, such as a neck and a flange, on a can body adjacent an open end thereof using a mandrel having an outer surface comprising generally cylindrical portions on each side of an annular recess which recess has a surface configuration corresponding to the neck and the flange to be formed. A resilient deformable object is located around the mandrel. A portion of a can body is placed between the mandrel and the resilient, deformable object which is then deformed so as to move a portion of the can body into conformation with the surface of the annular recess. At the same time, a force is applied to a portion of the portion of the can body being deformed to resist the movement thereof so that the portion of the can body in which the neck and flange is being formed is stretched and thinned as it is moved into conformation with the surface of the annular recess.

Abstract: An apparatus and process for expanding a tube at selective points about its circumference to join another tube. After a segment of a first tube is inserted into a second tube having an end sleeve segment with a larger diameter and wall thickness than the first tube, compression and subsequent radial expansion of elastomeric bars lodged along the generally open sides of a bushing located within the first tube end segment cause the elastomeric bars to radially expand the wall of the first tube. The wall of the first tube expands at selective points against the wall of the second tube in proximity to their respective ends, creating a selective interference fit therebetween.

Abstract: An apparatus and method for radially expanding a tubular member and comprising first and second spaced apart end caps rigidly connected to each other by a post. An expandable bladder fixed to each end cap and extending around the post to define an annular space. A propellant disposed in the annular space and ignition apparatus associated with the propellant. The propellant being of the type which burns rapidly to generate large amounts of gas for expanding the bladder. The tubular member being disposed around the bladder for radial expansion.

Abstract: A method of forming a deformable body to desired shape includes the steps(a) providing a bed of flowable particles within a contained zone,(b) relatively positioning said particles adjacent one side of said body,(c) and pressuring said bed to cause pressure transmission via said particles to said body, thereby to deform the body into desired shape.

Abstract: A built-up camshaft is fabricated by fitting cam disks on a hollow shaft, fitting shaft end caps over the ends of the hollow shaft, placing the resulting structure in a die, compressing the hollow shaft in the axial direction thereof inwardly from the opposite ends thereof thereby to carry out swaging tube expansion thereof to place all parts in a temporarily fixed state, and introducing a fluid under pressure into the hollow shaft thereby to carry out bulging and expansion of diameter at specific parts of the hollow shaft and obtain an integral built-up camshaft.

Abstract: A tubular metal member undergoes expansion transverse to the longitudinal axis of the member. An axial compressive load is applied to the member parallel to the member's longitudinal axis, and the member is allowed to deform transversely to said axis. Procedures are employed to control the deformation of the member, to prevent the member from buckling, and to ensure that the ends of the member will be expanded uniformly with the remainder of the member.

Abstract: A method for manufacturing ornamented head lug pipes comprising a first stage for lug-forming and ornamenting and a second stage for finishing ornaments, wherein:in the first stage, a bulge-forming rubber body is inserted into a tubular steel blank of required length having an outer diameter identical to the diameter of the finished said blank is placed in a die including therein a lug-forming cavitied section and a stepped section for applying pressure to the middle periphery thereof, and bulge-forming is effected under pressure to form a lug by bulging of the rubber body and form ornaments are formed on both ends of the blank there by reducing the diameter of said middle periphery, andin the second stage, the product from the first stage is fixedly placed in a die compressing a concave section for engagement with said lug, a concave section for engagement with said ornaments equal in diameter to the outer diameter of said blank and a concave section for engagement with the middle periphery of said blank, an

Abstract: A method for radially expanding tubes within a tube sheet involves the application of radially expansive swaging forces from a pre-expander apparatus and a hydraulic mandrel. The pre-expander is used first and includes at least one primary expander and at least one secondary expander. The expanders surround and are compressed axially by a draw bar, thereby producing outwardly directed radial pressure against the interior surface of the tube anchoring the tube within the tube sheet. An unexpanded land remains between the two expanded regions corresponding to an axially incompressible spacer that separates the expanders. Next, the hydraulic mandrel, which has seals that define the ends of a pressure zone, is inserted in the tube and positioned so that both seals engage unexpanded portions of the tube, one of these unexpanded portions being the land.

Abstract: A box-like frame member is formed by deforming the sides of a tubular blank inwardly to provide it with concavely recessed portions in areas corresponding to generally opposing flat surfaces of the product. The deformed blank is expanded, under internally applied fluid pressure, within a sectional die which has its die cavity preferably no more than about 5% larger than the circumference of the blank, to avoid weakening, cracking or yielding of the blank through excessive circumferential expansion.

Abstract: A tube bulger for producing an enlarged ring-like bulge in the material around an end portion of a metal tube includes upper and lower die sections. When the upper and lower die sections are mated together, a cylindrical hole is formed. The end portion of the tube to be bulged extends into the hole. A ring-like, outwardly oriented enlargement of the cylindrical hole in the mated die sections forms a bulge cavity into which the bulge moves as it is being formed. An elongated mandrel extends through the opposite end of the cylindrical hole and into the open end of the tube. First and second sealing rings disposed about the mandrel on opposite sides of the bulge cavity prevent leakage of pressurized oil between the die and the mandrel. An oil conducting channel has an opening between the sealing rings.

Abstract: An apparatus for sizing of tubes under the pressure of fluid comprises a split die (2) with a lock mounted on a bed (1) and provided with a horizontally arranged sizing channel (3) corresponding to the shape of a tube (7), a mandrel (6) for setting the tube (7) in the sizing channel (3) coaxially therewith, a means for delivery of fluid into a clearance (10) between the mandrel (6) and the tube (7), packings (19) for sealing the clearance (10) between the mandrel (6) and the tube (7), a hydraulic striker unit (24) for building up the pressure of fluid in the clearance (10), incorporating a working chamber (34) filled with a fluid and a vertically arranged receiver (30) with a barrel (25) wherein slides a striking ram (26) which at the impact builds up the pressure of fluid in the working chamber (34) connected to the sizing channel (3) of the die ( 2) through the medium of an adapter (36) joined to the sizing channel (3) and provided with a piston (37) serving for isolating the fluid filling the working chamb

Abstract: A tube expanding technique for securing a sleeve within a tube whereby fluid pressure is applied via an expander by incrementally decreasing the volume of the fluid system exclusive of the expander, or by incrementally increasing the mass of the fluid within the system. The system pressure and the rate of pressure increase as a function of incremental change in volume, or mass, are monitored. A decrease in the rate is indicative of the onset of plastic expansion of the sleeve or tube, as the case may be. By determining this point, the outer diameter of the tube may be accurately controlled to within six thousandths of an inch. A tube expanding device including a distensible sealed bladder for applying the expanding pressure and containing the system fluid.

Abstract: A tube bulger for producing an enlarged ring-like bulge in the material around an end portion of a metal tube includes upper and lower die sections. When the upper and lower die sections are mated together, a cylindrical hole is formed. The end portion of the tube to be bulged extends into the hole. A ring-like, outwardly oriented enlargement of the cylindrical hole in the mated die sections forms a bulge cavity into which the bulge moves as it is being formed. An elongated mandrel extends through the opposite end of the cylindrical hole and into the open end of the tube. First and second sealing rings disposed about the mandrel on opposite sides of the bulge cavity prevent leakage of pressurized oil between the die and the mandrel. An oil conducting channel has an opening between the sealing rings.

Abstract: A rupture disc system comprises a rupture disc including a dome portion and a flange portion interconnected by a transition region and a mounting mechanism for mounting the rupture disc by the flange portion thereof in a pressure relieving vent. The rupture disc includes a thickness reducing groove at least partially circumferentially surrounding the dome portion and located in the transition region thereof. Preferably, the rupture disc is of the reverse buckling type and the groove does not completely surround the dome portion so as to define a tab or hinge within that part of the transition region which is ungrooved or not as deeply grooved as a remainder of the transition region. In addition, the slope or radius of curvature may be increased in the region of the tab. The rupture disc also includes an indentation on the dome portion. The indentation is preferably greatest on the dome portion at a location spaced from the transition region and directly between the tab and a crown of the dome portion.

Abstract: A swaging apparatus includes a mandrel to be inserted in a tubular structure that is to be expanded radially. A pair of seals define the axial boundaries of an annular pressure zone between the mandrel and the tubular structure. One or both of the seals includes a support formed by a plurality of arcuate segments elastically held together and presenting a cam surface. A cam member interacts with the cam surface to expand the support radially in response to swaging pressure, thereby preventing inelastic deformation of an elastic member on the high pressure side of the support.

Abstract: An apparatus for expanding tube ends in a tube sheet of a heat exchanger tube bundle comprises a mandrel which can be inserted into the tube end and an expansion pressure generator connected to said mandrel. A source of filling liquid is also connected to the mandrel to the expansion pressure generator which has a port for the filling liquid selectively blocked by the plunger of the expansion pressure generator so that problems with check valves for the filling can be obviated.

Abstract: Apparatus for the blast hydroplastic finishing of tubular billets, comprising a housing to which there are attached front and back stops, while the back stop has a blast chamber and a work tool disposed in it. In the back stop, after the blast chamber, there are a guiding chamber and a compensating chamber, the three being interconnected. The work tool in its initial position is disposed against a rest in the guiding chamber. The tool has a center blind hole and radial channels connected thereto, and in the front end of the work tool there is a gasket. In the front stop there is mounted a fixed ram and there is positioned a traveling cylindrical piston with a center blind hole wherein the tubular billet is disposed. One end of this cylindrical piston slips over the fixed ram so that a recoil chamber is formed, the recoil chamber being connected to the compensating chamber through longitudinal grooves in the traveling cylindrical piston.

Abstract: A sealing member for use in a swaging apparatus includes an annular heel from which inner and outer lips extend to define an annular cavity. The outer lip has a first portion extending radially outwardly and axially away from the heel and a second portion extending radially inwardly and axially away from the first portion. In a relaxed condition, the inner lip is angled radially inwardly from the heel. This sealing member can be used on a swaging mandrel in combination with a harder back-up sealing member and a centering sleeve that carries a flange. The flange is tapered to a pointed edge and engages a conical back surface of the heel.

Abstract: There is disclosed a method of forming a furnace cooling element involving casting a metal block or plate (10) around one or more elongated metal tubes (11) which have a protective coating applied thereto, and thereafter the, or each, metal tube (11) is explosively expanded by an explosive charge (12) closer to the surrounding material of the metal plate (10). Also disclosed is a method in which the protective coating on the metal tube is replaced by a full length external shroud tube (21) to increase the thermal efficiency of the cooling element, the inner metal cooling tube (20) is explosively expanded by an explosive charge (23) closer to the surrounding shroud tube (21) prior to casting a metal plate or block (28) around the tube combination (20, 21) to minimize the gap (22) between the outside wall of the metal cooling tube (20) and the inside wall of the metal protective shroud tube (21).

Abstract: A swaging apparatus for expanding a tube radially to form a joint, the apparatus including a mandrel for insertion in the tube. A working fluid is supplied through the mandrel to apply hydraulic pressure to the tube. The mandrel carries a pair of oppositely directed ramps, and a pair of seal combinations that are movable axially along the ramps. The seal combinations define the ends of an annular volume within which the pressurized fluid flows between the mandrel and the tube, each seal combination including a softer primary seal, which may be an O-ring, and a harder backup seal. Positioning sleeves that are axially slidable on the mandrel prevent angular movement of the backup seals relative to the longitudinal axis of the mandrel, thereby maintaining a uniform circumferential extrusion gap between the mandrel and the tube when pressure is applied.

Abstract: An annular workpiece (114), in blank form, is snugly received within a central opening portion of an annular die member (78) having a radially inwardly directed die face. The two ends of the workpiece make sealing contact with radially inwardly sloping outer sidewall portions (118) of annular seal grooves (116) formed in support members (36, 54) for the two ends of the workpiece (114). The support members (36, 54) and the annular die member (78) are heated, by the use of induction heating apparatus (38, 42, 80, 100, 102, 52, 54), while a molten metal is pressure fed into the interior of the workpiece. The molten metal is pressurized while it is within the workpiece and it functions to both heat the workpiece and press it radially outwardly into forming contact with the die face. As the workpiece is being stretched in this manner and is taking the shape of the die face, the two end support members (36, 54) are being moved relatively together.

Abstract: Process and apparatus for expansion shaping of at least one localized region in a running portion of the wall of a tube of substantial length, wherein the distance between the expanded region and one of the ends of the tube is to be adjusted with precision; comprising disposing a die around the tube in the region to be shaped, the die comprising an expansion chamber between two cylindrical bearing surfaces, introducing a mandrel into the interior of the tube in the portion thereof which is within the die and delimiting an annular space between the mandrel and the tube, by two sealing regions disposed on respective sides of the expansion chamber at the location of the cylindrical bearing surfaces of the die, introducing a pressure fluid through the mandrel into the annular space, and increasing the pressure of the fluid until the tube becomes deformed against the walls of the expansion chamber.

Abstract: A method and apparatus for expanding a tubular workpiece which includes mounting the workpiece in a lower die, filling the workpiece with fluid and engaging the upper portion of the workpiece with an upper die. The upper die is moved downwardly acting to physically compress the workpiece. The dies are additionally configured to form an internal pressure cavity such that further downward displacement of the upper die creates an internal pressure forcing the workpiece outwardly into the desired end configuration.

Abstract: Disclosed is a method and apparatus for cold-working annular workpieces by applying thereto an internal fluid pressure to cause an enlargement of the diameter thereof through plastic deformation, in which the openings at opposite ends of an annular workpiece are closed by a pair of presser plates through packings which are radially expansible along with the annular workpiece. The contacting surface pressure of the packings and presser plates are controlled to a predetermined value by an arithmetic unit operating on detected values of a main pressure acting internally on the annular workpiece, an auxiliary pressure pressingly holding the presser plates against the respective packings and varitions in the shape of the annular workpiece undergoing the plastic deformation.

Abstract: An upper die is movable by a ram downwardly against a lower die with the dies enclosing a hollow article such as a knobshell in die cavities thereof. RAM continued downward movement of the closed dies forces a piston connected to the lower die downwardly against hydraulic fluid of a containing cylinder forcing the hydraulic fluid internally of the knobshell through the neck thereof forming the knobshell outwardly against the die cavity surfaces. The piston size compared to the knobshell size automatically creates a reactive force reversely tending to maintain the dies closed greater than the internal knobshell forming force tending to separate the dies. After knobshell forming, reverse ram movement first relieves piston pressure against the hydraulic fluid and ultimately separates the dies with a knockout member being actuated to eject the formed knobshell.

Abstract: In a device for confining a pressurized working fluid within a tube to be expanded radially, a support to be positioned axially within the tube and at least one sealing member encircling the support. The sealing member is deformable so that it expands radially against the inside of the tube upon axial compression by the force of a pressurized working fluid introduced into the tube. A centering means is provided that prevents angular movement of the sealing member relative to the longitudinal axis of the tube, thereby forcing the sealing member to assume a radially centered position within the tube as it expands.

Abstract: A two-stage method of expanding tubes into holes in tubesplates including walls of drums and headers especially in boilers using an elastomeric body which in a first stage is compressed axially in the tube and which expands radially to expand the tube beyond its elastic limit into close engagement with the hole wall. In a second stage a second elastomeric body of different dimensions is compressed axially to stress the tube and an annular zone of the tubeplate around the tube beyond their elastic limits. Problems of excessive extrusion of and damage to the elastomeric body where tolerances on tube or hole diameter produces excessive clearances are avoided even where high expansion forces are used.

Abstract: Apparatus for forming a corrugated tube from a smooth walled starting tube comprises a pair of receiving mandrels aligned spaced from each other along a preferably vertical axis and movable toward and away from each other to be engaged in opposite end portions of a starting tube. The halves of split corrugation forming discs and the halves of an end member above the uppermost of the discs, coupled together for limited movement in axial direction, are respectively carried and guided for movement in axial direction by a pair of clamping jaws tiltable between an open position permitting to align a starting tube with the mandrels and a closed position closing the split discs and the split end member and fluid tightly clamping opposite end portions of the starting tube located about said mandrels respectively between one of the mandrels and the closed end member and between the other mandrel and the clamping jaws.

Abstract: A hollow blank, such as a tube, is inserted in between two dies and is also received by two retractable die members. The interior of the blank is closed off, but working fluid is admitted to widen the blank. Widening is at first restricted to a central portion established by conical front faces of the die members. These members are retracted while continued application of fluid pressure progressively widens the blank, urging blank material into continued abutment with the front faces of the receding die members.

Abstract: A brush-beater assembly for a vacuum cleaner comprises a hollow cylinder having outwardly extending projections formed in the material thereof, and slots diametrically opposed to the projections for receiving brush assemblies. The projections may be formed pneumatically or hydraulically in the cylinder, during the production thereof. An additional projection is provided in front of the brush assemblies.

Abstract: Apparatus for forming a sheet metal pulley from a cup-shaped blank in a single hydraulic forming operation. A pair of die holding members supports a plurality of groove-forming inner dies and is movably mounted on a base for horizontal reciprocal movement between open and closed die positions for capturing a pulley-forming blank therebetween. Tapered pins extend vertically through aligned openings formed in overlapping shelf members of the die holding members to wedgingly clamp the dies toward each other and to lock them in a horizontally closed position. A ram plate is mounted on a plurality of vertical posts for reciprocal vertical movement with respect to the captured blank. The ram plate has a top die which exerts axial pressure on the hub portion of the blank during the hydraulic bulging of the blank side wall by a confined fluid within the blank in cooperation with the groove-forming inner dies.

Abstract: Apparatus for producing a tube with successive corrugations of different configuration from a tubular blank of uniform diameter mainly comprises a central pin having a shaft portion fixed only at one end to a stationary support and having at the other end a radially enlarged head portion cooperating with radially inwardly movable clamping and forming jaws to clamp a portion of a tubular blank therebetween. The apparatus includes further a tubular member guided on the shaft portion of the central pin and movable in axial direction by hydraulically operated members cooperating therewith.

Abstract: A method for molding a bulge comprises a step of jetting a pressure fluid from a nozzle into a shaped blank fitted thereto thereby causing air trapped in the shaped blank to be agitated into air bubbles to allow the fluid pressure to be applied onto the inner surface of the shaped blank during discharging the liquid from within the blank.

Abstract: Apparatus for producing a tube with successive corrugations from a tubular blank of constant diameter comprises a central pin having a shaft portion fixed only at one end to a stationary support and having at the other end a radially enlarged head portion cooperating with radially inwardly moving clamping and forming jaws to clamp a portion of a tubular blank therebetween. The apparatus includes further a tubular member guided on the shaft portion of the central pin and movable in axial direction by hydraulically operated members connected thereto.

Abstract: A method of manufacturing a cup-shaped coil assembly is described which employs a coil bobbin of a special design. The bobbin comprises a cylindrical member, a disc connected with one end of the cylindrical member to close it, a cap member detachably fitted into an opening in the other end of the cylindrical member, and a shaft disposed in alignment with the axis of the cylindrical member and having its one end attached to the disc and its other end slidably extending through the cap member. The method comprises the steps of assembling a coil bobbin in the manner mentioned above, and forming a coil around the bobbin by a skewed winding of wire, pressing the cap member into the cylindrical member, diametrically enlarging an opening formed at one end of the coil, and removing the cap member from the coil formed.

Abstract: An apparatus for the manufacture, by the hydroforming process, of expansion bellows for pipelines or the like, the apparatus being of the type comprising, for contracting longitudinally a sleeve to be formed, an actuating chamber of annular configuration defined by a rigid sleeve associated with the sleeve to be formed, a cylindrical skirt, and two sealing rings, one of which constitutes one of the supports for the sleeve to be formed. The apparatus is characterized in that the annular chamber is arranged, not outside, but inside the rigid sleeve, in such a manner that the hydroforming circuit is completely separate from the actuating circuit.

Abstract: A hollow spherical article having at least two substantially diametrically opposed apertures in the spherical surface, said article being of wrought metal and having been moulded by explosive forming. The article may further comprise at least two cylindrical portions, said portions being located on the spherical surface and defining said apertures. The method of forming the hollow spherical article comprises placing a tube of wrought metal into a die, positioning a plurality of explosive charges within the tube and detonating the explosive charges to expand the tube to form said hollow spherical article having two cylindrical portions which may subsequently be removed by machining.