Abstract: An irregular tube straightener is disclosed, which comprises a machine frame, upper and lower pulley blocks which are configured on the front side of the machine frame and work together to reshape the irregular tube, and an adjusting device mounted on the machine frame and used to adjust the size of the gap between the upper pulley block and the lower pulley block. The adjusting device comprises an adjusting screw rod mounted on the machine frame, a handle fixed on the upper end of the adjusting screw rod, a lifting and lowering seat configured on the back side of the machine frame, and a threaded bushing fixed inside the lifting and lowering seat. The threaded section on the lower end of the adjusting screw rod is spirally fitted inside the threaded bushing. The upper pulley block comprises at least two upper pulleys.

Abstract: Provided is a rolling straightening machine which enables outer-diameter-reducing rolling and straightening rolling of a pipe or tube material or a bar material at high speed with high accuracy. The rolling straightening machine includes at least two rollers arranged across a pass line of a pipe or tube material or a bar material, the at least two rollers having a gap therebetween, the gap being defined by an outer-diameter-reducing rolling portion having a diameter reduced from an upstream side toward a downstream side in the rolling straightening machine and a straightening rolling portion continuous from an exit side of the outer-diameter-reducing rolling portion toward a downstream side of the rolling straightening machine, the rollers having shapes which are symmetrical about the pass line in the outer-diameter-reducing rolling portion, and in the straightening rolling portion, asymmetrical to the pass line in the outer-diameter-reducing rolling portion.

Abstract: A press assembly for forming outer helical splines on a blank includes an upper press shoe assembly and a die shoe assembly. The upper press shoe assembly includes an upper rotatable portion rotatable relative to an upper stationary portion. The lower portion includes a lower rotatable portion rotatable relative to a lower stationary portion. The unfinished blank is supported by the lower portion, and the upper portion is moveable into engagement with the blank. The upper rotatable portion joins with the lower rotatable portion for conjoint rotation relative to the upper and lower stationary portions via upper and lower helical meshes defined between the rotatable and stationary portions. The helical meshes convert downward force into rotation and translation of the blank into a spline forming die of the lower stationary portion to create the outer helical splines.

Abstract: A method for preparing an ultrafine-grained superalloy bar, the method including: 1) designing a rolling machine including two rollers and two guide plates, where each of the two rollers includes a first roller and a second roller; the first roller includes a first curve and the second roller includes a second curve; the first curve and the second curve form a generatrix of the two rollers; 2) disposing the two guide plates with two curved surfaces thereof opposite to each other; disposing the two rollers to be between the two guide plates; where the two rollers and the two guide plates form a deformation zone of the rolling machine; and 3) driving the two rollers to rotate around their central axes, heating and introducing a superalloy blank from a gap between two first rollers to the deformation zone of the rolling machine; advancing the superalloy blank towards two second rollers.

Abstract: The present disclosure relates to a method for producing a profiled hollow shaft for a telescopic steering shaft of a motor vehicle. A hollow shaft to be machined and a roller forming head having at least one roller are provided. A groove is produced in the hollow shaft by moving the hollow shaft relative to the roller forming head. In order to provide an improved and less expensive method for producing a profiled hollow shaft for a telescopic steering shaft of a motor vehicle, the hollow shaft is moved relative to the roller forming head exclusively in the direction of the longitudinal axis of the hollow shaft. The disclosure also relates to a steering shaft having rolling body raceways.

Abstract: Method for producing a compound, rotationally symmetrical component (3) with internal and external teeth consisting of a blank (1) and a toothed body (5), wherein the two parts (1, 5) are designed in the form of a pot and in a first method step are inserted coaxially one inside another with interlocking, mutual support and in a second method step are interlocked together with at least one forming tool (17, 27) applied against the (inner and/or outer) circumference, wherein in the second method step the circumferential surface (14, 14?) of said blank (1) is continuously deformed in a rolling forming process in the axial direction and in the radial direction such that the circumferential surface (14, 14?) of the blank (1) is deformed to interlock into the tooth bases (10) of the teeth (6) of the toothed body (5).

Abstract: A solid billet is piercing-rolled using a 4 roll-type inclined rolling mill including larger-diameter cone-type main rolls arranged horizontally or vertically to face each other across a pass line and smaller-diameter auxiliary rolls arranged vertically or horizontally to face each other similarly across the pass line between the facing main rolls, while maintaining a feed angle ? and cross angle ? of the main rolls and a feed angle ?? and cross angle ?? of the auxiliary rolls to be within the ranges: 5°?“?, ??”?25°; 3°?“?, ??”?35°; and 10°?“?+?, ??+??”?55°.

Abstract: A method of reshaping a cylindrical pipe to a ground screw foundation for attaching an object to the ground includes a drawing unit and a working tool having a plurality of press roll disks or press roll disk segments. The press roll disks or press roll disk segments are disposed radially around a longitudinal axis of a holder for the cylindrical pipe, and pivotably around shafts extending at a fixed distance to the longitudinal axis transversely and tangentially relative to the longitudinal axis. A cylindrical pipe is inserted into a holder. The cylindrical pipe or the working tool with the drawing unit is drawn such that a relative movement between the pipe and the working tool is created.

Abstract: The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

Abstract: A wireless network device includes an antenna array and a lobe interleaver. The antenna array includes a plurality of antenna elements with different squint angles. The lobe interleaver is coupled to the antenna elements and has a plurality of output lobe ports. The lobe interleaver divides and interleaves the radio signal of the antenna array with the same phase and the same power to generate a plurality of lobes with different squint angles. The number of lobes is twice the number of antenna elements.

Abstract: A thread rolling method for a gear using cylindrical dies in which no slippage occurs. The method includes placing a work having a cylindrical outer surface to be supported to a support to be freely rotatable about a rotation axis of the cylindrical outer surface; placing a pair of the cylindrical dies each rotatable about an axis parallel to the rotation axis to face each other across the work; thrusting the pair of cylindrical dies against the work; and determining an outer diameter of the work, when rotary movement of the cylindrical dies and the work rotated together is shifted from friction gear movement to gear movement, in which a dimension obtained by dividing an outer circumferential dimension of a dedendum circle of the tooth grooves by the number of teeth to be formed is equal to an addendum circular pitch of each of the cylindrical dies.

Abstract: The present invention provides a mandrel mill and the like that is capable of not only enhancing the elongation ratio of the pipe or tube, but also suppressing a pinhole defect from occurring. The first means of the present invention provides a mandrel mill comprising a plurality of rolling stands in which two grooved rolls R11, R12 are disposed, respectively, the mandrel mill being characterized in that the roll diameter ratio for the first rolling stand and the second rolling stand is set at a value of 4.6 or over. The second means of the present invention provides a mandrel mill comprising a plurality of rolling stands in which three grooved rolls R21, R22 and R23 are disposed, respectively, the mandrel mill being characterized in that the roll diameter ratio for the first rolling stand and the second rolling stand is set at a value of 2.8 or over.

Abstract: A finishing station of variable structure includes two plates, joined integrally to each other and able to slide along two vertical shoulders which support a plurality of forming rollers mounted on shoes able to slide in radial guides formed in the plates. The shoes that support the forming rollers are moved by levers hinged to the plates and connected to each other by connecting rods, two of which are hinged to levers hinged to the plates and secured to the ground. A further forming roller, situated in the lower part of the plates, is preferably secured to the ground. In the inner part of the two forming rollers situated in the upper part of the finishing station a disc blade is formed to control the position of the edges of the bent strip of sheet metal during the finishing operation.

Abstract: A dynamic bearing manufacturing includes steps of: providing a bearing and a processing tool, the bearing having an axial hole, and the processing tool having at least one protruding pattern formed on an exterior wall of the processing tool; positioning the processing tool into the axial hole of the bearing; pressing the processing tool to contact with an inner wall of the bearing so as to transfer and print the protruding pattern of the processing tool onto the inner wall of the bearing; rotating the processing tool at a first rotation speed and driving the bearing to rotate at a second rotation speed; and forming at least one concave pattern on the inner wall of the bearing, and the at least one concave pattern being corresponding to the protruding pattern of the processing tool.

Abstract: A double-wall pipe includes an outer pipe, and an inner pipe disposed inside the outer pipe. An outer wall of the inner pipe has thereon a ridge portion, which defines a groove portion extending in a longitudinal direction of the inner pipe. The outer pipe and the inner pipe are bent to have a straight portion extending straightly, and a bend portion bent from the straight portion. In the straight portion, the outer pipe has an inside diameter that is larger than an outside diameter of an imaginary cylinder defined by an outer surface of the ridge portion of the inner pipe. Furthermore, the ridge portion of the inner pipe contacts an inside surface of the outer pipe to be readially squeezed and held by the outer pipe, in the bend portion. The double-wall pipe can be suitably used for a refrigerant cycle device.

Abstract: By using a plating bath containing chromic acid: 100 to 250 g/L, sulfate radical: 3.0 to 5.5 g/L, and a catalyst: 100 to 200% (a weight ratio to the chromic acid content) for conducting electroplating, a Cr-plating film which has an increased film crack density is formed on the surface of a mandrel bar base metal, whereby peeling-off of the Cr-plating film can be suppressed in mandrel mill rolling for extending the service life of the mandrel bar.

Abstract: The invention relates to a method and a device for transversely rolling stepped hollow shafts or cylindrical hollow parts from a pipe. The invention achieves the object of rolling stepped hollow shafts of the most varied dimensions and also of greater lengths in a flexible manner from a pipe using a small number of simple tools. In accordance with the invention, the object is achieved by virtue of the fact that rolling tools which can be radially advanced and are disposed in a planet-like manner around the workpiece are used to roll the contour of the transition from a central diameter in one portion of the workpiece to the central diameter in the adjacent portion by means of co-ordinated control of the radial advance of the rolling tools and the axial feed of the workpiece, and a mandrel head having an outer diameter which is adapted to the smallest inner diameter of the two portions is disposed underneath the rolling tools.

Abstract: A production apparatus for a tapered steel pipe which holds the two ends of the steel pipe by shafts on carriers and moves it in the axial direction while rotating it to draw it to a taper by an intermediate working roll, wherein the shaft of the working roll is inclined 20 to 40 degrees with respect to the axis of the steel pipe and a roll caliber of the working roll is made an outwardly curved surface with little difference in roll peripheral speed; the face plate for mounting the working roll is positioned and supported with respect to the body by a hinge mechanism and is fastened to the body by fastening members; and the bearing of the working roll at the side close to the steel pipe is made smaller than the bearing at the side far from the steel pipe and the two bearings are connected by a tie-rod.

Abstract: An apparatus and method are provided for reducing the width of a plurality of longitudinal slots or other openings spaced circumferentially around a slotted tubular member. The invention includes a seaming roller positioned to contact the outer surface of the slotted tubular member for transverse movement across the plurality of slots, and adapted to apply a force onto the slotted tubular member so as to reduce the slot width. The width of the plurality of slots is detected and compared to a set value indicative of a desired end slot width and based on this comparison, an adjustor connected to the seaming roller, adjusts the force applied by the seaming roller to the plurality of slots. Each opening is adjusted by the seaming roller to have a profile with a width that throughout the length of the slot profile, varies no more than a given tolerance from the desired end slot width.

Abstract: A machine may produce a tube having textured internal and external surfaces in a single operation. Inner and outer knurling tools may form the textured surfaces. The texturing of the internal and external surfaces may be helical patterns of ribs and grooves. The height of the ribs formed in the internal and external surfaces may be less than about 35 mils. The angles of the patterns relative to a longitudinal axis of the tube may be less than about 45°. The angle of the helical pattern allows textured tubes to be used as heat exchanger elements wherein flow is directed substantially coaxial to the longitudinal axes of the tubes. The helical pattern formed in the external surface may be oriented in a right hand or left hand helical orientation. Similarly, the helical pattern formed in the internal surface may be oriented in a right hand or left hand orientation.

Abstract: A method of forming a finned tube in which the fins are planar, paralleled and extend radially to the tube longitudinal axis, including the steps of positioning at least one rotating forming roll against the tube exterior surface, the forming roll being spaced from the tube and rotatable about an axis that is parallel to said tube longitudinal axis, the forming roll having on the surface thereof an elongated helically arranged fin forming protrusion, the helical protrusion having a pitch of “x” and linearly advancing the tube past the forming tool a distance of “x” for each revolution of the forming roll.

Abstract: This method refers to a method by which the physical and mechanical properties intrinsic to a fine-grain structure may be formed in metal billets using pressure treatment. The method is designed to treat rods, bars and other particularly long billets. This method is designed to lower the cost of deformational treatment for long rods and large diameter billets and creates a pre-specified microstructure, including micro-crystal structure, and specific physical and mechanical properties. This may be achieved using various treatment techniques, one of which includes the deformation of at least a part of the billet through reduction of the billets cross-section. In this method, a long rod shaped billet is used. Reduction of the cross-section is achieved using tools that permit movement along and across the billet's axis as well as being rolled about its surface, for example, a roller. In this case at least one support stand is employed for correct placement of the billet.

Abstract: A metallic heat transfer tube, in particular for the evaporation of liquids from pure substances or mixtures on the outside of the tube. Fins are integrally formed on the outside of the tube. Recesses are arranged in the area of the base of the primary grooves and extend between the fins. The recesses are in the form of re-entrant secondary grooves. The mechanical stability of the tube is not negatively influenced because material is primarily removed from the fin flanks toward the base of the groove so that the re-entrant secondary grooves are radially open.

Abstract: This method refers to a method by which the physical and mechanical properties intrinsic to a fine-grain structure may be formed in metal billets using pressure treatment. The method is designed to treat rods, bars and other particularly long billets. This method is designed to lower the cost of deformational treatment for long rods and large diameter billets and creates a pre-specified microstructure, including micro-crystal structure, and specific physical and mechanical properties. This may be achieved using various treatment techniques, one of which includes the deformation of at least a part of the billet through reduction of the billets cross-section. In this method, a long rod shaped billet is used. Reduction of the cross-section is achieved using tools that permit movement along and across the billet's axis as well as being rolled about its surface, for example, a roller. In this case at least one support stand is employed for correct placement of the billet.

Abstract: This method refers to a method by which the physical and mechanical properties intrinsic to a fine-grain structure may be formed in metal billets using pressure treatment. The method is designed to treat rods, bars and other particularly long billets. This method is designed to lower the cost of deformational treatment for long rods and large diameter billets and creates a pre-specified microstructure, including micro-crystal structure, and specific physical and mechanical properties. This may be achieved using various treatment techniques, one of which includes the deformation of at least a part of the billet through reduction of the billets cross-section. In this method, a long rod shaped billet is used. Reduction of the cross-section is achieved using tools that permit movement along and across the billet's axis as well as being rolled about its surface, for example, a roller. In this case at least one support stand is employed for correct placement of the billet.

Abstract: The present specification discloses a swaging press including a piston member (30) cooperable with a plurality of die shoes (40) to drive the die shoes inwardly upon axial movement of the piston member (30) during a swaging operation, the piston member (30) having a frusto-conical recessed region (31) divided into a plurality of circumferentially disposed bearing surface zone (33) of a defined axial length, each of the bearing surface zones (33) having an inner axial end (35) with a numerical radius of curvature less than or equal to the radius of curvature of a circular line (36) forming the lateral edges of each of the bearing surface zones (33) at the inner axial end (35) whereby at least 50% of the outer bearing surface (41) of each said die shoe (40) remains in bearing engagement with the adjacent said bearing surface zone (33) over the axial movement of the piston member (30) during a swaging operation.

Abstract: By attaching a base portion to a cover portion formed is an outer fixing body and in the interior of the outer fixing body a corrugated tube is rotatably received. Further, by providing a tube bend restraint portion at the end portion of the cover portion for restraining bend of the corrugated tube within the given range, a rotary holder for corrugated tube in which the range of sliding movement of the corrugated tube is defined only within the cover portion.

Abstract: A method of spin forming an open-ended container or other cylindrical metal workpiece by inserting a conically tapering mandrel coaxially therein and pressing the side wall of the workpiece against the inserted mandrel with plural symmetrically arranged forming discs while unidirectionally translating the workpiece, and independently translating the mandrel, relative to the forming discs.

Abstract: According to the spinning processing method of the invention, a steel tube (4) as a work is rotated round its longitudinal axis (X). A plurality of forming rollers (23), which are arranged around the steel tube (4), are rotated round the steel tube axis (X) in the direction (&bgr;) opposite to the direction of rotation for the steel tube (4). The forming rollers 23 are further moved toward the steel tube axis (X) into pressure contact with the steel tube (4), while being moved relatively to the steel tube (4) in the axial direction (A-B) thereof, to draw the steel tube (4) to form a section of reduced diameter. The relative rotation of the steel tube (4) and the forming rollers (23) in the opposite directions (&agr;, &bgr;) increases the relative rotation speed between them and shortens the processing time.

Abstract: An improved apparatus and method are provided for spin-forming tapered rollers, including but not limited to conveyor rollers, drum pulleys, web feed rollers and the like, from a tube without using any internal or external supports between the ends of the tube. The apparatus includes first and second clamp assemblies which support opposite ends of the tube. A rotation structure rotates the tube as a plurality of rollers engage the outer surface thereof. The rollers move between the clamp assemblies to alter the outer diameter of the tube during travel. A controller controls the urging of the rollers against the tube and controls the movement of the rollers between the clamp assemblies.

Abstract: A lubricant is provided for use in hot working such as cross-roll rolling of a seamless steel pipe. It effectively reduces the friction coefficient between the working tools and the material under the hot work, thus extending the lives of the tools. The lubricant contains: (A) from about 10 to about 60 wt % of alkali silicate; (B) from about 1 to about 20 wt % of silane coupling agent; (C) from about 0.1 to about 5.0 wt % of at least one kind of alkali compound selected from a group consisting of an alkali hydroxide, an alkali carbonate, an alkali borate and an alkali salt of mineral acid; and (D) from about 30 to about 70 wt % of water. Alternatively, the lubricant contains: (A) from about 10 to about 60 wt % of alkali silicate; (B) from about 1 to about 20 wt % of silane coupling agent; (C) from about 0.1 to about 5.

Abstract: A device for guiding a rotating hollow blank emerging from a cross-rolling mill, especially an Assel mill, which device includes at least two tubular guide rollers that extend over the length of the hollow blank and are arranged next to each other below the delivery plane and parallel to the delivery direction of the hollow blank. The guide rollers are supported by support rollers arranged below the guide rollers. The speed of the guide rollers and the support rollers is synchronized with the delivery speed of the hollow blank. The guide rollers are adjustably mounted on inclined guide blocks. A plurality of upper guide rollers are pivotably mounted so as to be able to contact the outer surface of the hollow blank. Disk type rollers are arranged between the guide rollers to lift the hollow blank away from the guide rollers for ejection from the cross-rolling mill.

Abstract: Apparatus for spin closing an open end of a tube of a suspension strut comprising a throughbore having a longitudinal axis; a first pair of rollers, each roller of the first pair being rotatably mounted in a bore opening into the throughbore, having a contact surface at a first predetermined angle to the longitudinal axis and which extends into the throughbore, and being biased such that the contact surface can retract from the throughbore against the action of biasing means; and a second pair of rollers, each roller of the second pair being rotatably mounted in a bore opening into the throughbore, and having a contact surface at a second predetermined angle to the longitudinal axis and which extends into the throughbore; wherein the second predetermined angle is greater than the first predetermined angle; and wherein the first pair of rollers is offset from the second pair of rollers along the longitudinal axis such that, on insertion, the open end of the tube of the suspension strut will make contact with t

Abstract: A moveable cage which has a pattern of holes surrounding and concentric with a central axis of the cage, and a short hard pin located within the cage, and movable back and forth between the two ends of the cage. A single drive device attached to the cage causes both translation and rotation of the cage. As the cage is advanced and rotated, the interior pin is caused to move backward and forward as the balls roll over the surface of the pin, so that the wear on the balls and on the surface of the interior pin is evenly distributed.

Abstract: A device for the formation by rolling of helical fins on heat exchange tubes to increase the heat transfer capacity of the tubes. The device comprises four forming rolls (6, 7, 8, 9) which are arranged on two carriages (4, 5) which are moved together in translation fashion by a hydraulic jack which enables the four forming rolls to bear simultaneously on the wall of a tube (2). The four forming rolls operate around the tube and are rotatably driven at equal speed by a single motor (50). The forming rolls are oriented about an axis (X2, X4, X5) which is perpendicular to the fin shaping zone. The tube (2) is driven by the forming rolls along an axis of translation.

Abstract: The invention relates to a device for manufacturing a hydrodynamic groove bearing formed with pumping grooves. The device comprises a hard pin around which, or a hard sleeve in which, a cage is arranged which has one or more annular patterns of holes which are concentric with the pin or sleeve and which are engaged by hard balls which project from both sides of the cage. The pin or sleeve and the cage can be translated and rotated relative to each other, the balls bearing against a bearing surface of the pin or sleeve. The bearing surface is constituted by a groove bottom of a continuous groove which is concentric with the pin or sleeve, the groove bottom extending in longitudinal sectional planes of the pin or sleeve as an arc of a circle whose radius is at least equal to the radius of the balls.

Abstract: A seamless tube mill comprises two disk rolls mounted to be driven in rotation on substantially parallel axes which axes are perpendicular to guide the workpiece along the pass line which rolls may be rotated away from the pass line to enable removal and replacement thereof without disconnecting and realigning the input shafts thereto.

Abstract: A finning and thread rolling machine capable of producing an integral finned tube, an extended finned tube or a wrap-on finned tube, whichever is desired, the tubing to be used for extended surface heat transfer. Types of tubes produced are integral low finned tube, bi-metal fin tube with extruded high finned tube on the outer portion, and extruded integral/high finned tube and spiral strip helical wrap-on finned tube. The apparatus also provides a two and three die thread rolling machine for thru-feed threading and form rolling.

Abstract: Rolling tools are rotatably mounted in rotatably driven rolling heads such that they revolve in a planetary-like fashion while the rolling heads rotate. The rolling tools thus roll with blows or impacts upon the outer surface of the rotating workpiece which is advanced along its lengthwise axis. A diameter reduction of the workpiece occurs and the workpiece material is predominantly displaced in lengthwise direction. The workpiece is moved along its axis in the feed direction at an axial feed velocity of at least 3 millimeters for each workpiece revolution, and in the case of hollow workpieces preferably at least at 5 millimeters per workpiece revolution. Difficulties which otherwise arise for certain materials can thus be avoided, and also the production speed and quality can be increased. For hollow workpieces, undergoing internal profiling upon a mandrel, the workpiece which is advanced at high axial feed is preferably also cold rolled during its return feed or motion.

Abstract: Improved method and apparatus for making finned tubing from difficult to work materials such as titanium and stainless steel uses spaced sets of finning discs on a plurality of arbors to form a tube against a mandrel having different diameters under each set of discs. By forming the tube fin tips to their final O.D. in a first disc set and by deepening their roots to bring the fins to their final height in a second disc set, tubes with higher fin counts and/or higher fin heights can be achieved than were formerly possible. The process of separately cold working the tips and roots also permits tubes to be made which are dimensionally identical to prior art tubes but with higher quality and productivity since tube stresses are greatly reduced. An improved titanium tube is also disclosed which has at leasts 26 fins per inch, a fin height of at least 0.034" and an outside to inside surface area ratrio of at least 3.0.

Abstract: According to the well known Grob method, there is fabricated on a mandrel provided with outer or external toothing or teeth a substantially dished or pot-shaped hollow body with corresponding inner or internal toothing or teeth. This fabrication operation starts with a blank comprising an at least partial web portion or dish base and a rim portion or dish rim projecting in a substantially tube-like or tubular configuration from the web portion or dish base. As seen in longitudinal section, this blank possesses a rounded or arcuate portion in the transition region or zone between the rim portion or dish rim and the web portion or dish base. This rounded or arcuate portion has a mean radius of curvature which is at least as large as the wall thickness of the rim portion or dish rim of the blank.

Abstract: In a skew-rolling stand for rolling hollow billets, in particular for stretching hollow billets into tubular blooms, work material guides are provided at the entry end and/or at the delivery end. These work material guides comprise a preferably motor-driven guide tube (19) which can be rotated about its longitudinal axis, which considerably improves guiding and offers additional protection against heat losses and scaling of the work material. The guide tube does away with the need for a re-heating furnace and allows immediate subsequent finish-rolling.

Abstract: The invention relates to a process for controlling a rolling mill having oblique rolls which is used for rolling metal rods or tubes, and to the rolling mill for carrying out the process. The rolling mill according to the invention comprises at least three rolls distributed round the rolling axis, each of the rolls having a profile generated by revolution of decreasing cross-section, the roll axes not intersecting the rolling axis, and each of the rolls exerting on the product a pressure which permits helicoidal rolling to be carried out. The process involves controlling the forward feed while keeping the angle of inclination of each of the axes of revolution of the rolls constant relative to a secant straight line, the so-called control axis, which is a straight line perpendicular to the rolling axis and intersecting said rolling axis and which traverses the zone of contact between the roll and the product to be rolled.

Abstract: The adjustment provides for three degrees of freedom, in which in addition to varying the distance of the rolls from the rolling axis an adjustment axis is provided generally parallel to the rolling axis and about which the roll mount can be tilted. This adjustment axis itself may also be tilted for changing the speeding of the rolls.

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

Abstract: A secondary working apparatus for secondarily machining a blank formed with internal serrations on a cylindrical plane, comprising a stationary housing structure, support means for supporting the blank with the center axis of the cylindrical plane fixed with respect to the housing structure, a plurality of shafts each having a center axis parallel with the center axis of the cylindrical plane and rotatable with respect to the housing structure about an axis coincident with the center axis of the shaft and an axis coincident with the center axis of the cylindrical plane, each of the shafts having a cylindrical eccentric axial portion having a center axis parallel with and radially offset from the center axis of the shaft, cylindrical machining tools coaxially carried on the eccentric axial portions of the shafts, respectively, and each having a center axis coincident with the center axis of the eccentric axial portion of each of the shafts, and an annular guide gear coaxially held in position about the center

Abstract: A secondary working apparatus for secondarily machining a blank preliminarily formed with internal serrations, splines or teeth on a cylindrical plane, comprising a stationary housing structure, support means for supporting the blank with the center axis of the cylindrical plane fixed with respect to the housing structure, a plurality of shafts each having a center axis parallel with the center axis of the cylindrical plane and rotatable with respect to the housing structure about an axis coincident with the center axis of the shaft and an axis coincident with the center axis of the cylindrical plane, each of the shafts having a cylindrical eccentric axial portion having a center axis parallel with and radially offset from the center axis of the shaft, and generally cylindrical machining tools coaxially carried on the eccentric axial portions of the shafts, respectively, and each having a center axis coincident with the center axis of the eccentric axial portion of each of the shafts, the machining tools incl

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

Abstract: In an apparatus for changing the rolling mill rolls and/or disk shoes of a steel pipe rolling mill, the top and bottom rolls vertically movably mounted in the housing are individually placed on a supporting bed positioned below the bottom rolling roll and moved in and out of the mill by way of rails laid in the lower part of the housing, and each of the disk shoes is mounted on a supporting arm which is movable vertically and rotatable thereby making it possible to change the disk shoes even during the operation.

Abstract: In a three-roll Assel mill capable of automatically and rapidly changing the rolls, rails are arranged on an inner housing mounted within each of a fixed housing and a rotary housing to be rotatable along the inner wall thereof, and cradles having rolls mounted therein are placed on the rails, whereby during roll changing the housing proper is shifted and the inner housings are rotated in such a manner that the rails provided on the inner housings are successively aligned with rails laid externally and the rolls are moved in or out of the rolling mill.