Abstract: Process and apparatus for bending thin-wall thermoplastic tubing utilizing pressure inside the tube portion being bent to thereby maintain the shape of the tube during bending, and applying heat only in the zone of the tube that is stretched by pulling it axially during continuous incremental bending around a rotatable bend die to thereby maintain the original cross-sectional shape of the tubing. The tube inside radius surface is continuously supported during application of bending-induced tensile stress by causing the tube to track or wrap partially around a rotatable bend die in a generally linear (minimum slip) tracking mode.

Abstract: A pipe bending machine, a segmented bending die for use in a pipe bending machine, and a method for bending pipe are disclosed. The pipe bending machine includes a frame, a segmented bending die, a support structure, a stiffback, and a pin up shoe. A pipe is inserted in the pipe bending machine, over the pin up shoe, between the segmented bending die and the support structure, and onto the stiffback. By raising the stiffback upwardly and securing an end of the pipe with the pin up shoe, the pipe is bent against the segmented bending die. The segmented bending die and the support structure conform to the external surface contours of the pipe to support the walls of the pipe, thereby preventing distortion, buckling, flattening, or collapsing of the pipe during bending.

Abstract: A first mandrel segment comprised of first and second resinous sheets including proximal end portions vertically spaced from each other is initially inserted into a pipe having a weld seam extending longitudinally thereof. Since the first mandrel segment has a thickness smaller than an inside measurement of the pipe, the first mandrel segment can be inserted into the pipe without being caught by a bulged portion of the weld seam protruding inwardly of the pipe. After the insertion of the first mandrel segment, a second mandrel segment comprised of a third resinous sheet is forced into a spacing between the first and second resinous sheets. By thus forcing the third resinous sheet into the spacing, the first resinous sheet is pushed vertically to come into intimate contact with the bulged portion. The pipe having the first, second, and third resinous sheets thus inserted therewithin is then bent by a bender. After the bending of the pipe, the third resinous sheet is first pulled out of the bent pipe.

Abstract: A pipe bending system employing a feedback and control system that provides continuous data to a programmed processor. The processor is programmed to automatically carry out an incremental bending cycle in which the pipe is clamped by a predefined pressure by the pin-up shoe, a stiffback is moved upwardly to a predefined position to achieve a desired angular bend in the pipe, the stiffback is returned to its fill back position, as is the pin-up shoe, whereupon the pipe is axially moved a predefined distance to proceed with the subsequent incremental bend.

Abstract: Stabilizer (1) for motor vehicles which has a toroidal cross section, and which is formed of several stabilizer sections that, together, create a U-shape having a pair of U-legs (2) connected by a U-back (3) via arcuately shaped transitional shoulder areas (4). The stabilizer (1), as a pipe stabilizer, is able to withstand the required number of load cycles even under very high stress or enables even greater weight reduction under normal stresses, by important stabilizer sections having an increased strength as compared to other stabilizer sections by either dimensioning, and/or increasing the carbon content of an outer and/or inner surface layer of the stabilizer (1) by carburization, and also, optionally, by at least partially shot peening the inner surface, preferably at least in the transitional shoulder areas (4).

Abstract: A process for production of a tube profile element having a swaged closed head end includes the steps of chamfering an unswaged end of a tube profile element having a first diameter to provide a chamfered end on the tube profile element having a chamfer angle of less than 45° relative to a longitudinal axis of the end portion of the tube profile element, supporting the tube profile element in a retaining tool such that an end portion of the tube profile element having the unswaged chamfered end thereon extends beyond the retaining tool, providing a swage tool having a negative die capable of swaging the end portion of the tube into a swaged closed head end having a maximum second diameter larger the first diameter of the unswaged end of the tube, and moving the swage tool toward the end portion of the tube and swaging the unswaged chamfered end of the tube, by the negative die of the swage tool, into the swaged closed head end of the tube profile element.

Abstract: A pipe bending apparatus is disclosed for bending pipe sections, particularly pipe sections of the type used in pipelines. The apparatus allows rapid clamping of the pipe section at reduced pressure via hydraulic fluid regeneration, while providing full hydraulic force for pipe section bending.

Abstract: A die-protecting device used in bending an embossed metallic straight pipe with a small diameter and a thin wall is disclosed. Whereof a die core is placed in the straight embossed pipe to support and help the wall of the embossed pipe to bear bending force being scattered thereby and almost equally distributed to the whole wall and to get desired bending curvature. A pair of half-dies are put on and envelop the external wall surface of the embossed pipe to protect the embossed pipe. A flexible plastic pipe is slipped over the half-dies to protect the half-dies from loosening. A spiral spring is slipped over the plastic pipe, and a tension spring is slipped over the spiral spring. So that the bending force exerted on the half-dies, the embossed pipe and the plastic pipe can be more uniformly distributed, and the embossed pipe can be bent to et desired curvature.

Abstract: A boost bend method of making tight radius bends in boiler tubes, such as bends having a radius of 1.times.D or less, in which a selected portion of the intrados of the tube is heated in a controlled manner thereby reducing the necessary tube wall thickness relative to the diameter of the tube for 180.degree. bends. Tubes bent using the method may have wall thicknesses of about 6.6% of the tube diameter and suffer less than about 7% thinning of the extrados tube wall.

Abstract: A bending machine has a machine bed on which a pipe supporting carriage is mounted to move a pipe in a first direction toward a dual bend head assembly at the forward end of the machine bed. The assembly has a support frame and first and second spaced bend heads each rotatably mounted on the frame for rotation about a horizontal bend axis aligned with the bend axis of the other bend head. Each bend head has at least one pair of opposing bend and clamp dies defining a die cavity. The dual bend head assembly is movably mounted on the forward end of the machine bed for movement in a horizontal direction transverse to the pipe axis between at least two horizontally spaced positions in which the pipe is aligned with the die cavity of the first and second bend head, respectively.

Abstract: Methods of making an inspection fixture to assess the accuracy of a manufactured, bent tube or tube assembly are disclosed. Coordinates of end points, intersection points, and other points of interest of the bent tubular part are provided to a CAD system. The coordinates are connected by a centerline. The centerline is projected onto an X-Y plane and widened. The projected centerline is extruded in the Z direction. The resulting three-dimensional extrusion is unfolded to form a flat pattern for a tube run. The process is repeated until flat patterns for the parts of a tube fixture are created. The resulting flat patterns are provided to a computer-controlled laser cutting machine. The inspection fixture parts are cut by the laser cutting machine and bent to their final shape in accordance with bend angle information generated from the three-dimensional extrusion in the CAD system. The bent parts are assembled on a base plate and welded together to form the inspection fixture.

Abstract: A method for bending metal tubing which minimizes the collapse of a tube wall through lowering material stress achieved by reducing the rate of bending. The method includes the steps of selecting a bend radius less than a standard bend radius, determining a rate of bending of a length of tubing so as to minimize material stress, and bending the tubing at the selected determined rate.

Abstract: Apparatus and method for the bending of rigid workpieces, particularly tubes, such as those of use in automotive exhaust systems, heat exchangers and aircraft hydraulic systems.

Abstract: An apparatus for bending forging an artistic metallic straight pipe, wherein, a die core made from a steel rope is placed in the pipe bore, a kind of filler including plastisol is then introduced into the pipe bore till it is saturated to form a solid straight pipe. The latter is placed in an upper and a lower bendable die housing which each forms a trough, both ends of the die housings are provided with latch holes which are inserted therein with supporting axles. Polyurethane is poured into the troughs to envelop the straight pipe. Many hard bracing stubs are buried in the top/bottom of the troughs, and after heating to solidify the polyurethane, a flexible die set is formed. Both external top and bottom surfaces of the upper and lower die housings are provided thereon with a laminated spring, so that when the die set is forged, action force can be uniformly distributed to render the straight pipe to be bending forged to have the desired bending curvature.

Abstract: A bending die or shoe having a semi-circular tube-receiving bending channel on its forward end, the bending channel merging into a straight lateral channel, where the die is improved by providing a fitting recess or notch on the side opposing the lateral channel, such that a fitting mounted onto a tube can be positioned in the recess whereby the end of the fitting abuts and the portion of the tube immediately adjacent the fitting is received by the curved bending channel such that a bend can be imparted to the tube immediately adjacent the fitting. Preferably the bending die is also provided with a sleeve recess or channel positioned between the fitting recess and the bending channel for use with fittings which have tubular sleeves extending a short distance from the fitting.

Abstract: This invention is concerned with an apparatus for bending a hollow double-structured pipe for use in an exhaust pipe of an internal combustion engine, for example, and aims at providing such hollow double-structured pipe which is capable of effecting favorable bending work, even in the case of using an inner pipe of a thin wall thickness.

Abstract: A resin-coated ribbed steel pipe that is provided with an axially extending rib that is made from the same material as the coating and forms a hold groove is fed forward and bent along with the rotation of a shaping roller that is provided with an accommodating groove having a shape identical to the half of the cross section of the pipe that includes such rib and also has a protruding wheel that inserts itself into the hold groove as the pipe is fed forward, the reaction force created thereby being managed by a device that, possessing a shape identical to the other half of the cross section of the pipe, suppresses the reaction force and yet allows the feeding of the pipe.

Abstract: A method for bend forging an artistic metallic straight pipe, wherein, a die core made from a steel rope is placed in the pipe bore, and a filler with plastisol uniformly mixed up is then introduced into the pipe bore until it is saturated to form a solid straight pipe. The latter is placed in an upper and a lower bendable die housing each of which forms a trough, and both ends of the die housings are provided with latch holes. Polyurethane is poured into the troughs to envelop the straight pipe, many hard bracing stubs are buried in the top/bottom of the troughs after heating, to solidify the polyurethane, a flexible die set is formed. The external top and bottom surfaces of the upper and lower die housings are provided thereon with two laminated springs, so that when the die set is forged, action force can be uniformly distributed to render the straight pipe to be bending forged to have the desired bending curvature.

Abstract: A cutter/bender apparatus is provided for selectively cutting and bending a workpiece. The bending member includes a bending pin actuated by a hydraulic cylinder that moves the bending pin into and out of engagement with the workpiece to clamp the workpiece against a support plate. When clamped, another hydraulic cylinder lifts a movable bending member toward the workpiece, bending the workpiece about the bending pin in the process. The cutting member includes a fixed cutting member and a movable cutting member mounted in side to side abutment. The cutting members include a slot that extends laterally therethrough in which the workpiece to be cut is placed. The hydraulic cylinder that operates the movable bending member also provides motion for the movable cutting member. As the movable cutting member moves, it moves the aligned slots of the individual cutting members out of alignment, shearing the workpiece in the process.

Abstract: A method for treating heat exchanger tubing to be expanded by fluidic or electromagnetic expansion. The tubing treatment reduces the increased material hardness of the tubing in areas where cold work has been imparted thereon. By reducing these areas which have increased material hardness, the tubing will have a substantially similar tube yield along its entire length and can therefore be expanded to substantially the same cross-sectional area throughout by either fluidic or electromagnetic expansion. After forming the cold work regions, the regions are annealed with a heat source, such as through flame or induction heating, and are gradually cooled to avoid the effects of quenching.

Abstract: Both a method and apparatus are disclosed for forming a bend in an elongated member, such as a tube, at a predetermined target angle. The elongated member is first bent to an angle equal to the target angle plus a predetermined increment. The elongated member is then returned to the target angle and a value representative of the force necessary to maintain the elongated member at the target angle is inputted into a central processor. This inputted value is then compared with a threshold value and, in the event that the inputted value exceeds the threshold value, the predetermined increment is incremented and the above steps are repeated until the inputted value is less than the threshold value. An apparatus for performing the method of the present invention is also disclosed.

Abstract: A torsion bar has a torsion bar arm and a torsion bar back connected thereto in one piece. Successive longitudinal sections are provided with different cross-sections. Consequently, a permissible maximal tension is not exceeded at any point and a relative weight optimum is achieved.

Abstract: An apparatus for bending a tube blank having an outer diameter, comprising: an inner bending die having an arcuate outer surface which has a first radius from an axis; a wiper shoe having an inner surface, said shoe disposed and adapted to trap a tube blank between said inner surface and said outer surface; holding means for holding a first portion of the blank against said inner die; limiting means for limiting movement of said shoe to rolling about an arc around said axis, said arc having a second radius from said axis which is approximately between said first radius and said first radius plus said diameter; and, moving means for moving said shoe around said axis, and around the blank thereby bending a second portion of the blank around said outer surface; and sealing and pressurizing means for sealing the blank and for hydraulically pressurizing the interior of the blank to a sufficient pressure to allow moving means to bend a second portion of the blank around said outer surface, said pressurized liquid a

Abstract: The present invention relates to a method of forming a sharp small radius bend in a rigid thermoplastic pipe having a close fitting metal sleeve without kinking or cracking in the thermoplastic at the bend. Furthermore, the invention comprises a rigid thermoplastic pipe having a metal sleeve with a bend formed in the area of the sleeve.

Abstract: A method for producing a U shaped seat back frame from a single extruded blank. The blank's cross section is nearly circular, but with a pair of short, flattened off crests that create a pair of concentric arcs, in cross section. Over a length of each end of the blank, a rectangular cross section, solid mandrel is inserted between the crests and the arcs are flattened against the mandrel. The arcs are flattened into wider side walls, while the crests move apart, without deformation, to create narrower and stiffer walls of a rectangular cross section. Lastly, the U blank with flattened ends is bent into a U shape, creating an upper beam with a nearly circular cross section, and legs with truly flat and rectangular lower ends.

Abstract: This rodless cylinder is a rodless cylinder of pneumatic driving slit type, and a cyliner tube is provied with a curved part bent in the axial direction, and a slit of nearly trapezoidal section is formed along the longituinal direction of the inner circumferential side of the curve, and a seal belt with both ends fixed within the cylinder tube is arranged to be fitted to the slit and a piston is inserted within the cylinder. The piston has a piston body and seal pistons connected rockable to both sides of the piston body, and the piston body is provied with a connecting part projecting from the slit to the outside and a belt inserting hole for insertion of the seal belt. On an outer circumferential part of the piston body and the seal pistons, an annular groove with a bottom being a part of a spherical surface is formed and a wear ring having an inner circumferential surface with the same curved surface is inserted slantwise within the annular groove.

Abstract: The present invention provides an apparatus and process for shaping at least an end of a tube to a desired form by incremental axis shifting. This is accomplished by providing an apparatus including an inside/outside end sizing machine and a work table having a plurality of stop blocks associated therewith such that an angle cut perforated tube is presented to the machine at preset angles set by the stop blocks. The tube is aligned adjacent the first stop block and is presented to the inside/outside end sizing machine. The machine is then cycled and begins to align the center line of the tube with the center line of the tooling. However, the stop block prevents the tube from moving which results in the axis of the end of the tube being shifted. This process is repeated for a plurality of stop blocks which are used to alter the angle of presentation to the end sizing machine.

Abstract: An insulating glass unit is shown comprising a pair of generally parallel, spaced-apart glass-panes and a spacer peripherally joining the glass panes to each other. The spacer is a tubular structure, and may include a particulate desiccant filling at least a section of the interior and conforming to the interior configuration thereof to contribute compressive strength to the spacer. The spacer desirably is made from stainless steel sheeting having a thickness not greater than about 0.005 inches. In a preferred embodiment, the spacer includes side walls sealed to the glass panes and an outer wall extending between the side walls and having a sealant free portion between the side walls that extends substantially completely about the periphery of the glass unit.

Abstract: A system for determining the bend in a section of pipe which is being bent by a bending machine which includes a stiffback and a pinup shoe. The pipe to be bent is placed in the stiffback and extends out the end at the pinup shoe and its angle S.sub.i is obtained of the pipe with respect to the horizontal. An outboard and an inboard cylinder force the pipe and the stiffback against a die to obtain a bend. This system is especially good for determining the angle of bend when the bending machine is on a non-level surface. After such bending, the angle of the pipe S.sub.h at the pinup shoe with respect to the horizon is made, and then subtracting S.sub.i from S.sub.n to obtain the angle of bend of the pipe. In another embodiment the angle detector is calibrated to read zero when the angle detector is measuring the actual angle the pipe makes with the horizontal before the pipe is bent.

Abstract: For the advance of the slide rail of a pipe bending machine, a hydraulic cylinder (22) is provided. The pressures (P1,P2) on both sides of the piston (23) of the cylinder (22) are detected, and from these pressures, the actual value of the advance force (F) is calculated. A set value generator (49) generates the set value (Fs) of the advance force in dependence on the respective rotational angle (.alpha.) of the bending template. A controller (48) controls a throttle valve (42) such that the actual value (Fi) follows the set value (Fs). Thus, a power control of the slide rail advance is effected.

Abstract: A method and apparatus for bending a heat-exchanger tube, which heat-exchanger tube have heat-exchanger ribs preferably having a needle construction. In the method and apparatus, the heat-exchanger tubes are placed one above the other to be defined by one another to form a battery. The battery of heat-exchanger tubes is fed first into a first bending-device portion of the bending device in which the heat-exchanger tube is bent in one direction. After this, the tube battery is fed further, and the bending is performed in the second bending-device portion in the opposite direction of bending, whereby a wave-shaped form is obtained.

Abstract: An insulated window panel assembly for use in window and door assemblies having an improved insulating spacer between the window panes comprising the panel assembly. At least two panes of glass or other panel material are interconnected in parallel, spaced relationship by a spacer assembly. The spacer assembly is preferably a single length of tubing, generally rectangular in shape, having an outer wall of a first width interconnected to an inner wall of less width by generally concave sidewalls. The sidewalls also contain a bead of sealer material configured to seal with the adjacent window panes. A secondary seal is deposited on the outer wall and overlaps the sidewalls to also form a seal with the window panes. The spacer assembly is preferably one piece, bent to conform to the overall shape of the window panes wherein a first end of the spacer is connected to the opposite end. Folds may be made in the spacer along a crimp line formed in the inner wall to accommodate angular window pane configurations.

Abstract: Method of effecting a supplemental bending operation on an initially bent workpiece which has been subjected to an initial bending operation at an initial bending position selected along the centerline of the workpiece, the method including a step of determining an actual relative position between the opposite ends of the initially bent workpiece, and determining, on the basis of the determined actual relative position, at least one of a supplemental bending position and a supplemental bending amount which are used for effecting the supplemental bending operation for reducing an error between the actual relative position and a nominal relative position between opposite ends of a product to be obtained by the supplemental bending operation, the supplemental bending position being different from the initial bending position, and a step of performing the supplemental bending operation at the determined supplemental bending position, so as to achieve the determined supplemental bending amount.

Abstract: According to the present invention, in the first process, a pipe end of a long pipe is bent with a radius of curvature which is larger than a minimum radius of curvature to form a large R portion. That is to say, bending with a large radius of curvature (R) is performed to form a large R portion in a region in which cracking or excessive reduction of plate thickness of the bend outer-side portion, or buckling of the bend inner-side portion does not occur. Subsequently, in the second process, the pipe is bent with a small radius of curvature form a small R portion by pressing a pipe-end portion of the pipe from a pipe-end direction while fixedly holding the bend side wall of the pipe. In this way, it is possible to obtain an R-minimum elbow configuration irrespective of magnitude of an amount of elongation of material and further without special equipment or mechanisms, by minor modification of present equipment.

Abstract: A discharging furnace and a filling furnace are disposed in three dimensions in the upper and lower positions of a filling and discharging furnace. A reservoir is provided in an inclined surface protruding toward the lower filling furnace. The reservoir includes a valve operatively connected thereto. A hot blast heated by a duct heater through a duct is mainly fed into the discharging furnace for further heating, while a remaining small portion of the hot blast is fed into the filling furnace for keeping the filling furnace warm. Inside the discharging furnace, a filling material filled in a bent workpiece is molten and discharged into the reservoir and when the valve is opened, the gathered filling material is filled into the inside of the workpiece which is carried by a filling carrier. The filling carrier is divided into three portions of a filling pallet, a carrier body and a sealing pallet, wherein the filling pallet is provided with a nozzle and the sealing pallet is provided with a seal member.

Abstract: A method of manufacture of a hollow stabilizer for automobiles which uses a heat-finished seamless steel pipe 20 as a material, comprising an inner surface and/or an outer surface of a part corresponding to a bending R portion A-B of the steel pipe 20 is polished to remove defects of the surface of the steel pipe, and after the above surface roughness is made less than Rmax 50 .mu.m, the part corresponding to the above bending R portion is previously formed an ellipse in section, and then the section after bending process accesses to a true circle to alleviate stress concentration of the bending part.

Abstract: A bending process including both preliminary and following steps takes place in one apparatus. A plastic pipe (6) is heated to a temperature in which it can be plastically deformed. The heated pipe is thereafter shoved into a pipe-shaped bending channel (27) of a bending tool, with the bending tool comprising two dies (9,10), each respectively defining a groove (14,13) which together form the bending channel. Finally, a cooling agent is allowed to flow through the bent pipe which is still in the bending tool. The thusly cooled pipe is removed from the bending tool after the dies are separated from one another. The apparatus to bend the plastic pipe comprises heating, bending, and cooling stations (1,2,3). The heating station comprises two heating fixtures, and the cooling station comprises a supply line (21,22) with a coupling joint (20) which can be coupled to an end of the pipe.

Abstract: A combination suction coagulator and dedicated bending tool for customizing working surfaces of suction coagulator instruments. A working extension of the coagulator is provided with an improved insulating coating and is adapted for customized bending with a dedicated tool that has at one end a recess with a centrally located mandrel pin for insertion into the hollow interior of the coagulator extension. A curved channel is provided in cooperative association with the recess and mandrel pin so as to limit the radius of any bend that may be made by the user. That, in combination with the form-fitting mandrel pin provide a ready way of bending the distal extremity of the coagulator extension while maintaining its internal geometrical integrity. The tool also includes a custom stylet for use in cleaning accumulated debris from the interior of the working extension.

Abstract: Apparatus and method for hydroforming a dual wall conduit having a controlled size gap between the walls, a frame having an upper crown and a lower bed defining a hydroforming space therebetween, the bed having a slideway extending from the space to a load-unload-preform position out of the space. A mold assembly on the slideway has a lower platen and an upper platen defining at least two hydroforming cavities, one cavity being an elongated preform and semi-finish cavity, and the other cavity being an elongated finish cavity. Mold shifting means is positioned for shifting the mold assembly on the slideway from the position in the space between the crown and bed, to and from the forward load-unload-preform position. Mold closing and preforming hydraulic cylinders are operably connected to the upper mold platen for closing the upper platen onto the lower platen and creating mechanical preforming on dual wall tubular stock in the preform and semi-finish form cavity.

Abstract: A filling material such as a fatty acid is filled into a metallic pipe in a molten state. The metallic pipe is then bent at a room temperature in a condition in which the filling material is solidified. After the bending work has been finished, the filling material is melted and discharged out of the pipe. The filling material may be a mixture of a fatty acid and a powdery additive.

Abstract: The invention relates to a method for bending plastic pipes in which a plastic pipe section is heated at the bending point. The feature of the invention is that the pipe section (4) is first heated in a water bath at about 80.degree. C. and then laid around one or more bending plates (3), depending on the desired shape, whereupon the bending plates are subjected to a heat source (5), for example a hot air blower, and partially heated, depending on the pipe material used, to a maximum of 160.degree. C. for 10 to 15 seconds, whereafter the pipe section is subjected to a first cooling process from inside of the pipe using cold compressed air for 10 to 15 seconds. The pipe section is then placed in a cold water bath.

Abstract: A stabilizer bar or a similar metallic tube product for vehicles, has a central portion and at least two bent portions forming legs. The bar includes a thick-walled metallic tube having in the central portion a wall thickness and outside diameter in a ratio amounting to at least 1/10. This tube has an outside wall portion bent with a restricted thinning, ranging from about 5 to 15%. The bent portions are bent with an average bending radius of curvature in the range from about 1.4 to 2.1 times the outside diameter of the tube. Apparatus and methods can manufacture stabilizer bars or similar tubular metallic products of the foregoing type. For example, a method includes the steps of fitting to a bending arm one end of the thick-walled metallic tube. An inside wall portion of the tube has a radial spacing from a bending center of curvature, no greater than the length of the bending arm. The tube and the heating zone move relatively, with the heating zone advancing along the tube.

Abstract: A composite tube and method of manufacture are provided. The composite tube is formed from a plurality of tube segments which are different from one another. The tube segments may differ in cross-sectional dimensions and/or material of manufacture. The tube segments are welded in end-to-end relationship to define a composite tube. The composite tube is then bent into a selected non-linear shape. Preferably, the welds are disposed at locations on tangents between adjacent bends. Bending forces and bending speed are altered from one bend to the next in view of anticipated strength and metallurgical characteristics of the particular tube segment in which the bend is being carried out.

Abstract: A bent metal tube of high quality having a bend formed with a small radius of curvature, and not having any flattened, cracked, broken, folded, or otherwise defective wall portion, and a bending process which can make the same efficiently. The tube has along the inside corner of its bend a thickened wall portion having a thickness of 2.0 t to 1.5 t (t is the wall thickness of work), and a pair of transitory wall portions formed on both sides, respectively, of the thickened wall portion, and each having a gradually decreasing thickness approaching the wall thickness t of the work, and a length which is at least equal to 1/3 D (D is the diameter of the work), while the bend has an outer peripheral configuration which is substantially equal to that of the work.

Abstract: The invention provides an apparatus for the rotary draw bending of pipe and tube having means to apply an axial boost force to the trailing end of the tube during the bending operation, which force assists in controlling the flow of tube material into the bend. The apparatus has means to monitor the amount of material being used during each bending operation and means to control the amount of boost applied to the tube whereby the bending operation can be controlled to better achieve desired elongation characteristics. Bent tubes to a consistent standard and quality are obtained.

Abstract: A heat exchanger is disclosed, which comprises:a plurality of tubes each having a U-shaped portion and arranged in a plurality of parallel bending planes, each bending plane containing a plurality of tubes of the same nominal outer diameter and of differing bending radius, the variation of the outer diameter of the tubes in at least one of the bending planes measured in a direction perpendicular to the bending planes being at most 0.1 mm; andan antivibration bar disposed between two of the bending planes.

Abstract: In manufacturing a metal bellows of high rigidity by using relatively simple equipment, a plurality of annular concavities are formed around the outer periphery of an unprocessed tube to form an intermediate product. Then, a core iron is inserted into the intermediate product while the annular concavities around the outer periphery are braced. Subsequently, the intermediate product is pressed in its axial direction to be formed into the metal bellows.

Abstract: A tube loading assembly for use in loading a tube on a flexible mandrel of a tube bending machine; said assembly comprising mandrel receiving means for receiving said mandrel; mandrel alignment means for aligning said received mandrel to be co-axial with said tube; and means for feeding said tube on said co-axially aligned mandrel. The assembly is of use with tubes to be bent for use in automotive exhaust systems, heat exchangers and aircraft hydraulic systems, and provides for improved automatic loading speeds.

Abstract: The invention relates to a process for bending pipes, which preferably are deformable or bendable when heated. In this process the pipe to be bent is heated, if need be, an inside support is put in, and then the bending operation is carried out. Prior to the bending operation a pipe-like inside sleeve (3) which is expandable up to a certain degree is inserted in the pipe (1) to be Dent, and the inside sleeve (3) is filled with a pressurized medium so that it comes to rest fully against the inside wall of the pipe (1) to be bent, whereupon the bending operation takes place. The apparatus for performing the process comprises an insertable flexible pressure pipe (3) of a material that expands under pressure, the ends of this pipe being fitted with sealing parts (5, 6), the outside diameter of which is not greater than the inside diameter of the pipe (1) to be bent.

Abstract: An improved tube rotary draw bending apparatus for bending a tube having a bend die around which a bend in the tube is formed, a pressure die and means for maintaining a pre-programmed frictional profile of the interaction of the tube with the pressure die during the bending operation. Improved quality of the bent tube is consistently obtained.