Abstract: Disclosed are a method and apparatus for manufacturing tubes, preferably tubes composed of high-tensile steels or special alloys, using the cold pilger rolling method with two rolling stands which can be moved backward and forward, at least in opposite directions at times and in the rolling direction by means of crank drives. The rolling stands have rollers which are calibrated in a tapering manner and which, driven by toothed racks via cogs, roll over the material to be rolled, with an alternating rotation direction. The majority of the forming work takes place on the first rolling stand and a relatively small portion of the forming work takes place on the second rolling stand and additional smoothing work is carried out.

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: An apparatus for bending a workpiece comprises a stretching device for stretching the workpiece. In the process for bending the workpiece, an inclination angle made by a direction a tension force is acted to the workpiece and a direction a stretching forth is applied to the workpiece by the stretching member is detected. The tension force acted to the workpiece is controlled in such a manner that the stretching force from the stretching member is controlled in consideration of the inclination angle. Accordingly, the amount of the spring back after bending is uniform and an accuracy of the dimension of the bent workpiece is improved.

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 method and device for folding a metal sheet to a well-defined angle, in which the sheet is deformed in the recess of a die through a punch being moved above the recess and pressing on the sheet, towards the die, until it reaches a well-defined end position. The movement of the punch is regulated as a function of the folding force and of the folding angle. The punch is moved in the direction of the die until it is in an end position Ya corresponding to: Ya=Yt-dYw-dYr in which Yt is a calculated position, dYw is determined through extrapolation of the course of the folding angle as a function of the position of the punch, and dYr is the correction of the position of the punch which is necessary to compensate for the spring-back of the sheet.

Abstract: During the process of bending a workpiece, actual load exerted on the workpiece and displacement are sampled and the bending stress to displacement relationship is obtained from the sampling data and data on the actual thickness of the workpiece. From the bending stress to displacement relationship, a material characteristic value (e.g., yield stress) which indicates the condition of the material of the workpiece is obtained. Then, a bending angle correction amount is obtained from the material characteristic value, using a data table concerning the material characteristic value to bending angle relationship. From the bending angle correction amount thus obtained, a correction depth amount is obtained. The correction depth amount is added to a preset reference depth amount to obtain a final depth amount according to which bending is performed.

Abstract: A process for rolling tubes, in which two grooved rolls mounted opposite one another in a roll stand are moved back and forth, i.e., reciprocated, on tube-shaped rolling material, which is arranged on a tapered rolling mandrel supported in the axial direction by a mandrel bar. The rotary-driven rolls have, on their circumferential surfaces, narrowing work grooves matching in shape to the tapered rolling mandrel, which roll down the rolling material on the rolling mandrel. At the ends of the work passes the rolls release the rolling material at the two dead centers of the roll stand path so as to assist in the advancement and rotation of the rolling material. According to the invention, the tube-shaped rolling material and the rolling mandrel are driven asynchronously in the same rotational direction at different rotational speeds.

Abstract: A process for drawing stretched metal workpieces, especially tubes, for the purpose of cross-sectional reduction in more than one drawing step using at least two sequential drawing aggregates. The aggregates grip the workpiece on the outer periphery, with two alternately-moved clamping carriages, which draw the workpiece continuously through respective drawing rings associated with the respective aggregates and arranged in respective drawing-ring holders. The drawing aggregates can be driven independently of one another in a power-regulated and/or moment-regulated manner. Furthermore, during the drawing process, a defined prestress force, which prevents deflection of the workpieces from a straight line, is maintained at all times in the section of the workpiece located between the drawing aggregates.

Abstract: A hand held, sheet metal forming tool for siding installation. A main frame comprises a base and an integral, semi-circular, ambidextrous handle. The operator simply pushes the tool along siding to bead or form it by grasping either end of the handle with either hand. A pair of spaced apart, cooperating press rollers press against opposite sheet sides. A deforming pattern defined in the upper roller and a mating deforming pattern that is slightly offset in the lower roller captivate and form siding sandwiched therebetween. An offset admission throat is formed at each end of the guide channel to ease sheet insertion. Siding entering either throat is captivated within a bifurcated guide channel longitudinally coextensive with the frame that preserves alignment. The guide channel comprises intersecting vertical and horizontal guide slots. As the tool moves, the upturned siding edge slides within a vertical guide slot, maintaining spacing and alignment.

Abstract: A system for adjusting the gram load of a suspension with a high degree of accuracy and repeatability includes a clamp, load-engaging member, actuator, laser and control system. The mounting region of a suspension to be adjusted is releasably received and clamped by the clamp. A load beam of the suspension is engaged and supported at adjust positions with respect to the clamp by the load beam-engaging member. The load beam-engaging member is driven and positioned by the actuator. IR light from the laser is directed to the spring region of the suspension by optical fibers. The control system includes a pre-adjust input terminal, memory and a controller. Information representative of a measured pre-adjust fly height gram load value of the suspension is received at the pre-adjust input terminal. Gram load adjust data representative of load beam adjust positions which will cause the suspension W have a desired post-adjust fly height gram load value after the load beam is stressed relieved is stored in the memory.

Abstract: In welded pipe manufacturing a steel strip is fed and bent by forming rolls into a pipe. A load detector is provided for a roll rotary shaft of each forming roll; a forming roll inclination adjustment device inclines the roll rotary shaft. The roll shaft load is measured to cause inclining of the rotary shaft counterclockwise or clockwise on a plane formed by the rotational axis of the forming roll and the advancing direction of the steel strip.

Abstract: A system for first setting a blind rivet and then verifying the correctness of the set comprising a rivet setting tool to set the rivet and computer logic to verify the correctness of the set. The setting tool includes a jaw assembly for holding the stem of the rivet's mandrel fitted to an axially movable pulling shaft. Both the pulling force of the setting tool and the displacement of the pulling shaft are measured and the measurements are interpreted by an integrator to determine the total energy of the setting process. The determined total energy is then compared with an ideal total energy to assess whether or not the set of the particular rivet is acceptable. Other quantitative comparisons may be made against other ideal values.

Abstract: The process relates to the aptitude for detectability of defects using eddy-currents on metal tubes cold laminated using a pilger mill and relates more particularly to the possibility of reducing the background noise and increasing the ratio between a standard signal and this background noise.The process consists of carrying out, after reduction in section by at least 30% in a cold pilger mill, a hollow drawing pass with a reduction in the external diameter of approximately 0.1% to 5%. The signal/background noise ratio can in this way be multiplied by a factor of between 2 and 3.7, in the case of a series of tubes made of INCO 690 alloy, as shown in the single figure.The invention also relates to tubes produced using this process.Application in production of steam generating tubes for nuclear power stations.

Abstract: A process for controlling a multiple stage drawing machine that implements a direct non-sliding drawing process provides for set-up and production to be automatic and for the variables necessary for process control, especially material speed and applied force, to be derived without establishing contact between the stock material and a sensing device.

Abstract: Disclosed is a process for producing a crimp-bonded fibrous cellulosic laminate. The process includes the steps of: 1) providing at least two superposed plies of a fibrous cellulosic material; 2) passing the superposed plies through a crimp roll arrangement including a rotating crimp element and a rotating anvil element; and 3) applying a pressure load against the rotating elements sufficient to crimp bond the fibrous cellulosic material plies into a laminate. The crimp element has protruding members configured in a discontinuous pattern aligned on an axis that is parallel to the cross-machine direction to provide a substantially continuous uniform area of localized surface contacts between the rotating crimp and anvil elements across the width of the plies. Also disclosed is an overall crimp-bonded fibrous cellulosic laminate and an apparatus for crimp-bonding multiple superposed plies of a fibrous cellulosic material.

Abstract: A device for guiding away a cold-rolled tube from a cold pilger rolling mill that at least one of intermittently feeds and rotates the tube. The device including a constant-speed driver for drawing the tube from the rolling mill. The driver is arranged downstream of the rolling mill so that there is a buffer zone between the driver and the rolling mill. Additionally, an apparatus is arranged in the buffer zone for diverting the tube out of a roll direction by restrictively guiding the tube so that the tube describes a roughly S-shaped path in the buffer zone whereby cyclically non-uniform rolling speed of the rolling mill is compensated for.

Abstract: A cold pilger rolling mill which has a roll stand that can be moved back and forth, a pair of cranks each having a crankpin, a pair of thrust rods that connect the roll stand to the crankpins, and centrifugal counterweights connected to the cranks so as to be eccentric to the rotational axis of the crank to at least partially balance inertial mass. The centrifugal weights are staggered by 180 degrees to the connection point of the respective thrust rod and crank and each crank and its associated counterweights forms a submechanism. The submechanisms are arranged in a mirror image around a vertical plane which intersects a roll axis. A common drive is provided for driving the roll stand. The drive includes a drive shaft that connects the submechanisms to one another and is located beneath a rolling plane. The submechanisms have rotational axes that run horizontally parallel to one another, and the drive turns the cranks in opposite directions.

Abstract: A roll tool for cold pilger rolling of pipes in which the reducing zones of the two tool grooves, starting from the transition from the reducing zone to the smoothing zone, have transitional areas without kinks which extend parabolically. The curve describing the mandrel groove runs parallel to the parabolic transitional area of the roll groove proceeding from the location of the narrowest gap between the roll and mandrel while forming a wall smoothing zone.

Abstract: A lightweight and easy-to-operate device for bending expansion loops in coaxial cable includes a bending frame which has on its upper surface pivoted brackets for securing the device to a support cable, so that the device may be slid into position and may be supported by the support cable during operation. The device also includes a pivoted bending handle with a bending shoe, which bending shoe bends and forms the coaxial cable along the profile of an arcuate surface of the frame. The bending handle is easily switched from one end of the frame to the other, to thereby bend both ends of the expansion loop against the arcuate form of the frame.

Abstract: A forward feed gear mechanism for a cold pilger rolling mill having at least one forward feed slide, whose advancing movement can be derived from at least one forward feed spindle which is driven in continuous rotation, and an oscillating axial movement can be superimposed on the rotational movement of the forward feed spindle so that the gear mechanism is flexible and adaptable to different settings and provides high acceleration values with a simplified gear unit design. A planetary rolling spindle is provided for generating the axial movement of the forward feed spindles and is coaxially connected with one end of the forward feed spindle so as to be independently rotatable. The housing of the rolling spindle is rigidly arranged in the forward feed gear mechanism housing and the planetary rolling spindle can be driven in rotation in a translatory manner by a separate drive via a spur gear unit stage.

Abstract: A system and method for monitoring a pilger mill having a crankshaft driving rolls with a reciprocating motion to reduce a tube over a mandrel. A linear sensor coupled to the mandrel supplies a mandrel position signal. A rotary sensor coupled to the crankshaft supplies a crankshaft angle signal. A processor for combining the mandrel position signal and the crankshaft angle signal provides a mandrel motion signal characteristic of the tube reduction.

Abstract: A process for cold pilger rolling of thin-walled pipes having small outer diameters in which calibrated rolls are moved along the intermittently stationary pipe, inside of which a roll mandrel which is likewise calibrated assists in the shaping of the inner and outer pipe in the shaping region. To produce pipes which are thinner and have thinner walls than was formerly possible, the pipe to be shaped and the shaping tools (rolls and roll mandrel) are warmed up to operating temperature before and/or during the starting rolling phase of the pipes to be shaped.

Abstract: For closing Pittsburgh-type rectilinear seams, as in conventional sheet metal heating and air conditioning ducts. The present machine, with only a single seaming roll, closes seams through 45.degree. to 90.degree. on an advancing stroke, and burnishes them on the return stroke. The machine functions without adjustment throughout substantially the entire range of sheet metal thicknesses normally utilized. Of particular advantage in manufacturing duct sections having integral end flanges, only an initial short length of seam need be peened manually before the duct elements to be seemed are clamped in place for completion. Workplace noise is greatly reduced.

Abstract: A rocker mill includes a pair of roll dies rotatably mounted in a structure and having tapered circumferential grooves for receiving a workpiece. A support is provided for supporting the structure so that it is longitudinally movable relative to the support. The support is rotatably mounted on a frame. A reciprocating driving apparatus is provided for reciprocating the roll dies longitudinally relative to the support through a reduction stroke and a smoothing stroke. A rotating driving apparatus is provided for rotating the roll dies around a longitudinal axis of a workpiece. A method of forming reduced diameter tubing is also described.

Abstract: Rapidly solidified aluminum base alloy is flow formed into tubes and tubular components using conventional flow forming equipment. A preform of preselected configuration and wall thickness for either forward or back spinning is fabricated. Flow forming is then carried out. The beginning of the flow forming step is offset by leaving undeformed a small section of the preform.

Abstract: A cold pilger rolling mill includes a reciprocating roll stand and a crank drive connected to the roll stand through connecting rods. The crank drive includes three shafts arranged parallel to each other and spaced apart at equal distances. The middle shaft is a crank shaft connected through crank pins with the connecting rod. A main weight for balancing half of the inertia forces of the roll stand is arranged eccentrically relative to the axis of rotation on the crank of the crank pin offset by 180.degree. from the pivot point of the connecting rod. On the two other shafts are arranged two additional weights of equal size which balance the other half of the inertia forces of the roll stand.

Abstract: An automatic stop apparatus for use in combination with a cold-pilger mill to reduce the amount of tube scrap generated during a cold-pilgering operation includes a first control scheme for stopping the advancement of the pilger mill feed carriage and the operation of the mill's upper and lower pilger dies when the feed carriage pushing a tube through the pilger dies is a predetermined distance from the axis extending between the centers of the pair of pilger dies. The predetermined distance is selected to provide that facing end portions of the pushed and pusher tubes are positioned between the pilger dies.

Abstract: A drive for a pilger cold rolling mill which includes a crankshaft and a connecting rod. The connecting rod provides a balancing or equilibrium of moments while the crankshaft provides a balancing or equilibrium of mass.

Abstract: Rolled stock is turned and advanced by a devicce that includes two separate motors the two motors being provided, being provided for turning while the advancing is of the stock results from a speed differential between the motors as they drive the stock.

Abstract: An improved apparatus for forming plates of irregular cross-sectional shape has a plate-form die which cooperates with a plurality of reciprocating rollers for forming a strip of plate material which is passed incrementally between the rollers and the die. The die includes a plate surface portion having a wedge-shaped leading end portion for forming a groove in the plate material. The rollers reciprocate with a stroke which is less than the length of the plate surface portion.

Abstract: A method of pilgrim step rolling of elongated stock includes reciprocating a roll stand or frame for moving the stock either by rotating it and/or advancing it; such a method is improved by providing a first component of movement at a constant speed and adding thereto, near each dead center portion of the reciprocating frame movement, a second component of motion including temporary accelerating and decelerating periods.

Abstract: An orientable bending assembly of a type capable of being temporarily retracted below the upper edge of a work platform (15) of a bending-shaping machine for sections is disclosed. The bending assembly is provided with clockwise and anticlockwise rotation of a bending pin (18) and contrast roll (12). A bending, e.g., disk (11) cooperates with and is supported by an orientable slide block (14) pivoted on an orientation pivot (16) lying in the neighborhood of a plane comprising the axis of the contrast roll (12), this plane being substantially parallel to the axis of the section or sections being bent and shaped.

Abstract: A rocker mill for reducing the diameter of metal tubes includes a rollstand mounted on a reciprocable sled. The rollstand includes upper and lower roll dies between which the tubes travel as the sled and rollstand are reciprocated. The roll dies are mounted on tapered segments of respective arbors to facilitate removal of the roll dies. The arbors are driven by respective spur gears which are in meshing relationship on one side of the rollstand. One of the spur gears is driven by a pinion gear coaxially attached thereto on the same side of the rollstand as the spur gears. The rollstand is arranged to be slid horizontally from the sled after a plurality of fasteners have been released. A stationary toothed rack which drives the drive gear is spring-biased vertically to raise the rack in order to facilitate the sliding of the rollstand off the sled.

Abstract: A technique for sealing a housing (10) is disclosed characterized by use of a multi-stage tool (50) specifically adapted to progressively cold roll and crimp seal one or more flanges (18) formed on a component (12) over a beaded edge (24) which, in one embodiment, may be formed on another component (14). The multi-stage tool (50) includes a series of laterally spaced roller dies (56A,56B,56C) configured to structurally support desired walls (15,16) of one or more of the components (12,14) during the process as well as progressively roll form and crimp the flanges (18) about the beaded edge (24) of the component (14).

Abstract: The present invention provides a device for bending thin metallic pipes suitably used as a fuel supply pipe, brake pipe and the like of an automobile, which are bent at a plurality of portions thereof not in the same direction but in three-dimensional directions. The device according to the invention includes a stationary mold form having a first and a second bending section to the shapes of which a metallic pipe is bent and a guide member erected upright on the mold form at the second bending section, a bending member arranged outside the mold form and movable toward the latter for bending the metallic pipe, a rotor for rotating the bending member and an actuator for operating the rotor through a wire.

Abstract: A method and apparatus for manufacturing seamless metal tubes by the cold pilger process permitting the continuous feeding of fresh cooling and lubricating agent between the mandrel and inner surface of the material being rolled. The apparatus includes a roll stand including tapering calibrated rolls (2) which is reciprocatingly movable in the direction of rolling at a predetermined stroke to define a reduction zone, the rolls (2) rolling with alternating direction of rotation over the material (3) being rolled and a tapering mandrel (1) inside the material for reducing the diameter and wall thickness of the material, wherein at least one of the rolls (2) and the mandrel (1) has a surface discontinuity within the reduction zone for creating a zone of interruption (6) or an annular gap within which no contact occurs between the material to be rolled (3) and the mandrel (1).

Abstract: A rocker mill includes a rollstand and a carriage for supporting and repositioning a workpiece extending through the rollstand. A first hollow-shafted electric motor is mounted on the carriage and includes a first hollow open-ended rotor and threaded nut through which the stationary feedscrew passes. The threaded nut is connected to the first motor to be rotated thereby in order to move the carriage longitudinally toward the rollstand. A second hollow-shafted electric motor is mounted on the carriage and includes a second hollow open-ended rotor and a clamp through which the workpiece passes. The clamp is actuated into clamping engagement with the workpiece for transmitting rotational and longitudinal movements thereto. Such mechanism for imparting rotary and longitudinal movements to the workpiece is of very low inertia and thus is able to reposition the workpiece with a high degree of precision.

Abstract: A method and apparatus for loading hollow workpieces into a pilgering mill. The pilgering mill includes a reciprocating roll stand having a pair of metal forming rolls, a mandrel for insertion into a workpiece, and a mechanism for clamping the workpiece with various degrees of pressure. During loading and unloading of the mill, the workpiece is restricted from movement within the pilgering mill according to the various pressures applied to the workpiece by the clamping mechanism.

Abstract: Pilger tooling for use in a pilgering machine includes an elongated stationary mandrel for supporting a tube thereon in position for cold reduction, and a pair of roller dies positioned along opposing sides of the mandrel and in oppositely-facing relation to one another for coacting with the mandrel in reducing the cross-sectional size of the tube. Each roller die is ring-shaped with a central opening for mounting the die on a shaft and has a keyway defined therein adjacent the central opening for receiving a key to secure the die for movement with the shaft. The keyway also provides a timing mark for accurately mounting the die on the shaft. Each roller die has two relief pockets formed in the periphery thereof in circumferentially spaced apart relation with a bridge extending therebetween, and a tube-reducing groove formed in the periphery thereof having a tapered configuration and opening at its opposite ends into the respective pockets.

Abstract: A drive for a pilger cold-rolling mill with mass and torque balancing, where the driven crank, rotating around a vertical axis, is connected via a coupler with a roller frame guided horizontally in a guide and where the coupler assumes, with its total mass, the balancing of momentum and where the crank, with its total mass, assumes the mass balancing. An additional mass M.sub.z, which is movable synchronously and parallel to the roller frame and where the center of gravity (S.sub.M) is lower than the virtual engagement point (S.sub.AG) of the centrifugal force of the crank balancing mass (MA), where the product of the force of inertia for accelerating the mass (M.sub.z) and of the vertical distance (b) between the center of gravity (S.sub.M) and of the mass (M.sub.z) and the engagement point (S.sub.AG) of the centrifugal force of the mass (MA) corresponds to the balancing mass moment obtained as a product of the force of inertia engaging at the center of gravity (S.sub.

Abstract: An inertia force balancing apparatus for a machine haivng a reciprocating heavy object, such as a Pilger rolling mill provided with a heavy object stand having a pair of Pilger mill rolls and horizontally supported such as to be reciprocable and with a drive device for imparting reciprocating motion to the Pilger mill stand by a motive power converted from rotational motion, into reciprocating motion. A spring device secured at its end to the heavy object and adapted to balance the inertial force of the reciprocating motion of the heavy object. A control device is provided for changing the spring force of the spring device in accordance with the rotational speed of the rotational motion of the drive device.

Abstract: The present disclosure relates to an apparatus and a method for deforming sheet metal plates and more particularly aluminium and steel plates. The objectives of this disclosure are realized by laminating a plate of sheet metal in juxtaposed and parallel strips. This method allows for the formation of spherical surfaces having a variable curvature. These strips are oriented according to predetermined axes according to the expected result.

Abstract: A pilgering die for use in cold forming of tubular members is in the shape of a ring member having a groove in the outer periphery thereof and a bore therethrough, the die composed of at least two different alloy sections. The case or outer region of the die is formed from a first steel alloy which hardens by transforming to martensite under predetermined heat treating conditions while the core or inner region of the die is formed from a second steel alloy that does not transform to martensite under the heat treating conditions used to harden the case. A third alloy section of a material which hardens by martensite formation may be provided adjacent the bore through the die. Also, the second alloy section may be comprised of a steel alloy that has a higher thermal expansion rate than the thermal expansion rate of the first alloy section.

Abstract: The method consists of a cold pilgrim rolling mill to effect a recoil movement of the chuck upstream followed by a return to its original position, at least once per rolling cycle. The period during which the chuck is withdrawn with respect to its rolling position is used advantageously for example to carry out the rotation of the chuck and/or to cause a lubricant under pressure to circulate between the chuck and the pipe. The method is applied particularly to the rolling of pipes with a large section, with high reduction rates.

Abstract: Pilgering apparatus for reducing a tube particularly of zirconium alloy. The reduction is effected by grooved annular dies. Each die has a recess in its bore extending between the surfaces on which the die is mounted on the shaft on which it is rotated. Under the pressure applied to reduce the tube, the die is flexed. As a result of the flexing tension exists in the die in the volume near the recess and pressure is developed in the volume near the groove in which the tube is engaged. The pressure counteracts the tension resulting from the tube-reducing pressure. Each die is case hardened in the region of its grooves but not in the region of the recess.

Abstract: The disclosed stand comprises a housing with carriers that are located pairwise on either side of the axis of rolling oppositely to each other and accommodate the bearing chocks of the work rolls. The work rolls are disposed one above the other between the backup rolls. A device for prestressing the stand is included. A device for prestressing the work rolls separately interconnects the bearing chocks of the work rolls of each pair located one above the other.

Abstract: The method consists of a cold pilger mill to effect a recoil movement of the chuck upstream followed by a return to its original position, at least once per rolling cycle. The period during which the mandrel is withdrawn with respect to its rolling position is used advantageously for example to carry out the rotation of the mandrel and/or to cause a lubricant under pressure to circulate between the mandrel and the pipe. The method is applied particularly to the rolling of pipes with a large section, with high reduction rates.

Abstract: A method and apparatus for producing tubing from hollows or workpieces which are in the form of tubes having greater wall thickness than the finished tubes. The method is carried out upon a mill of the general type known as a McKay rocker. The mandrel is allowed to float in the hollow by being restrained at the rocker crosshead by friction rather than a positive locking device. The rocking is permitted with the mandrel sliding in the crosshead so as to reduce high tensile forces which could otherwise cause mandrel failure.

Abstract: A method for cold rolling a tubular blank using a Pilger rolling mill, the tubular blank being rolled between a mandrel, lodged inside it, and the grooves of a pair of rolls, mounted within a stand which performs a back and forth motion along the axis of the tubular blank, the rolls being driven in rotation alternatively in one direction and in the other, in synchronism with the movements of the stand, a forward motion of the blank being done at least at proximity of the downstream neutral point. During at least a part of the return run of the stand, a holding back device, placed on the downstream side relative to the stand, prevents the displacement of the already rolled tubular blank along the rolling axis in the upstream direction during the return rolling run.

Abstract: A composite assembly knurling tool for forming uniformly-spaced horizontal serrations continuous across the surface of a metal flake producing drum is disclosed. The knurling tool comprises an alternating array of spacer and forming discs substantially conforming to the contour of the metal flake producing drum.