US3820373A - Apparatus for manufacturing leaf springs having a tapered end portion - Google Patents

Apparatus for manufacturing leaf springs having a tapered end portion Download PDF

Info

Publication number
US3820373A
US3820373A US00380580A US38058073A US3820373A US 3820373 A US3820373 A US 3820373A US 00380580 A US00380580 A US 00380580A US 38058073 A US38058073 A US 38058073A US 3820373 A US3820373 A US 3820373A
Authority
US
United States
Prior art keywords
leaf spring
pulse
metal band
pulse signal
logic circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00380580A
Other languages
English (en)
Inventor
H Shiguma
S Suzuki
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NHK Spring Co Ltd
Original Assignee
NHK Spring Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP47072876A external-priority patent/JPS5214822B2/ja
Priority claimed from JP7881373A external-priority patent/JPS5311959B2/ja
Application filed by NHK Spring Co Ltd filed Critical NHK Spring Co Ltd
Application granted granted Critical
Publication of US3820373A publication Critical patent/US3820373A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
    • B21B37/16—Control of thickness, width, diameter or other transverse dimensions
    • B21B37/24—Automatic variation of thickness according to a predetermined programme
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
    • B21H7/00—Making articles not provided for in the preceding groups, e.g. agricultural tools, dinner forks, knives, spoons
    • B21H7/007—Taper rolling, e.g. leaf springs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21H—MAKING PARTICULAR METAL OBJECTS BY ROLLING, e.g. SCREWS, WHEELS, RINGS, BARRELS, BALLS
    • B21H8/00—Rolling metal of indefinite length in repetitive shapes specially designed for the manufacture of particular objects, e.g. checkered sheets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2206/00—Indexing codes related to the manufacturing of suspensions: constructional features, the materials used, procedures or tools
    • B60G2206/01—Constructional features of suspension elements, e.g. arms, dampers, springs
    • B60G2206/40—Constructional features of dampers and/or springs
    • B60G2206/42—Springs
    • B60G2206/428—Leaf springs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2206/00—Indexing codes related to the manufacturing of suspensions: constructional features, the materials used, procedures or tools
    • B60G2206/01—Constructional features of suspension elements, e.g. arms, dampers, springs
    • B60G2206/80—Manufacturing procedures
    • B60G2206/81—Shaping
    • B60G2206/8109—Shaping by rolling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49609—Spring making
    • Y10T29/49611—Spring making for vehicle or clutch

Definitions

  • Leaf springs used in, for example, a vehicle are formed of an elongated metal plate whose end portions are tapered.
  • an apparatus comprising a shear for cutting a long metal band for every predetermined length to provide plate spring units, a punch for forming a center hole in the plate spring unit, a heater for heating one or both end portions of the plate spring unit, and means for tapering the heated end portion of the plate spring unit.
  • the object of this invention is to provide an apparatus which is compact and simple in construction and which is capable of producing leaf springs of high quality and high reliability.
  • FIG. 1 is a schematic illustration of method for manufacturing leaf springs using an apparatus in accordance with this invention
  • FIGS. 2A to 2C are side and plan views of the leaf springs produced at each step shown in FIG. 1;
  • FIGS. 3 and 4 are respectively a plan view and a side view of the apparatus in accordance with this invention.
  • FIG. 5 is a schematic illustration of the method for manufacturing leaf springs using the apparatus shown in FIGS. 3 and 4;
  • FIG. 6 is a block diagram of a control circuit for controlling a rolling mill roll used in the apparatus shown in FIGS. 3 and 4;
  • FIG. 7 illustrates the dimensions of a leaf spring manufactured with the apparatus under control of the control circuit
  • FIG. 8 shows an enlarged view of .part of the leaf spring shown in FIG. 7;
  • FIGS. 9A to 9D are sectional views of leaf springs produced with the apparatus.
  • FIGS. 10A to 10D are perspective views of the leaf springs which can be formed using another apparatus in accordance with this invention.
  • FIG. 1 there is schematically illustrated in FIG. 1 method for manufacturing leaf springs using an apparatus in accordance with this invention.
  • An elongated metal band 10 is heated to a predetermined temperature, for example 900C, at heating step A.
  • a heating furnace providing a furnace temperature of 900C may be used for this heat treatment.
  • the metal band 10 heated is transferred to taper forming step B to be pressed and tapered at predetermined intervals in the form as shown in FIG. 2A.
  • a portion 12 is defined by opposite tapered portions 11 to form a leaf spring unit. Then, the metal band 10 is fed to shearing step C to be cut along the broken lines (FIG. 2A)
  • the leaf spring unit 12 is reheated and fed to center hole forming step D to be bored with a center hole 13, thereby providing a complete. leaf spring unit 12 (FIG. 2C).
  • the center hole forming step D can be eliminated or carried out prior to, for example, the step C.
  • An apparatus of this invention for manufacturing leaf springs according to the steps mentioned above may be designated to continuously carry out the steps. Therefore, the apparatus may be made compact and simple in construction and is capable of producing leaf springs of high quality and high reliability.
  • FIGS. 3 and 4 illustrate an apparatus in accordance with this invention and the operation method thereof.
  • the apparatus is provided with a roller table 20 along which a metal band and leaf spring units sheared apart from the metal band are fed.
  • the front portions of this table 20 is so arranged as to introduce a metal band into a heating furnace 21 such as a well known lateral furnace.
  • Furnace temperature of this heating furnace 21 is preferably set at about 900C so that the metal band may easily be rolled.
  • a taper forming unit 22 Disposed following the heating furnace 21 is a taper forming unit 22 which includes a pair of rolling mill rolls 23 and 24, and two pairs of pinch rolls 25 and 26 respectively arranged at the input and output sides of the rolls 23 and 24.
  • Each leaf spring unit may be tapered at both end portions by pressing the leaf spring unit between rolls 23, 24 while the upper roll 23 moves vertically.
  • the leaf spring unit, now tapered, is fed along the roller table to the subsequent step, shearing step C.
  • the step C is carried out by a pair of shearing blades 27 and 28 arranged on the upper and lower sides of the roller table, respectively.
  • the upper blade 27 is hydraulically driven in a vertical direction against the stationary lower blade 28 to cut off the metal band at a portion between the adjacent tapered portions thereby obtaining discrete leaf spring units.
  • the roller table 20 is divided at a rear portion into two tables 20a. Disposed at the junction is a separating means 29 which selectively feeds the leaf spring units to the tables 20a.
  • the leaf spring units are fed to and reheated by reheating means 30 on the tables 20a.
  • the leaf spring units are fed to assemblies of punches 31 and dies 32 mounted on the tables 20a so as to carry out the center hole forming step D.
  • the punches 31 may be vertically moved to punch the leaf spring unit supported by the dies 32 so that a center hole may be formed at the center of the leaf spring unit.
  • a pulse generator is operatively connected to one of the pinch rolls 25 and other pulse generators 41a and 41b are connected to the lower and upper pinch rolls 26 respectively.
  • Each of the pulse generators 40 and 41a produces a pulse signal according to the rotation of the corresponding roll and the pulse generator 41b produces a pulse signal according to the vertical movement of the upper roll 26 or each when the upper roll 26 vertically moves through a predetermined distance.
  • the pulse generators 40, 41a and 41b are connected to the output terminals of a logic circuit 42 which stores the information on the dimensions of a leaf spring to be formed, that is, length of the front tapered portion 11a of the leaf spring unit, thickness t at the front end, length l of the rear tapered portion 11b, thickness t at the rear end, overall length L and thickness T at the center portion (see FIGS. 7 and 8).
  • the output terminal of the logic circuit 42 is connected to a pulse motor 43 so that the motor 43 may be rotated according to the output pulse signal of the logic circuit 42.
  • the motor 43 drives a screw down mechanism 44 which, in turn, drives the upper roll 23 in a vertical direction.
  • a pulse signal is generated from the pulse generator 40 each time a predetermined length of the metal band has passed through between the rolls 25 and then the pulse signal is applied to the logic circuit 42 so as to be processed depending on the preset value of the dimensions of the leaf spring stored in the logic circuit 42.
  • An output pulse signal is generated from the circuit 42 corresponding to its input sig nals and then applied to the motor 43 so that the motor 43 may be driven and vertically move the upper roll 23 to roll the metal band into a predetermined shape.
  • the leaf spring unit is tapered at the front end portion, first the upper roll 23 is set at the height equal to the thickness 1? at the front end of the leaf spring and then the upper roll 23 is upwardly moved through Ah each time the metal band advances through Al. The upward movement of the roll 23 may be stopped when the formation of the taper is completed. Likewise, the taper at the rear end portion of this leaf spring unit may be formed after the metal strip moves through a predetermined distance.
  • the pinch rolls 26 are provided to check that the leaf spring unit is tapered in a desired shape.
  • the lower pinch roll 26 rotates so that the pulse generator 41a may produce a pulse signal each time the leaf spring unit advances through a distance Al.
  • the pulse generator 41b may produce a pulse signal each time the upper pinch roll 26 vertically moves through a distance Al.
  • Both pulse signals generated from the pulse generators 41a and 41b are applied to the logic circuit 42 and compared with the preset values stored therein. If the leaf spring is not tapered in a predetermined form, the output signal from the logic circuit 42 is corrected according to the difference between said both pulse signals and the preset values stored in the circuit 42. The corrected output signal is applied to the pulse motor 43 so as to control the movement of the roll 23 thereby to roll the metal strip in a predetermined form.
  • the input and output side tapered portions may be formed symmetrically or asymmetrically.
  • FIGS. 9A to 9D illustrate leaf springs which may be made by the apparatus of this invention.
  • a leaf spring shown in FIG. 9A has end portions 11a, 11b linearly and symmetrically tapered with respect to the crosswise central line
  • a leaf spring of FIG. 93 has linearly tapered assymmetrical end portions 11a, 11b
  • a leaf spring of FIG. 9C has symmetrical end portions 11a, 1 lb tapered with the same curvature R
  • a leaf spring of FIG. 9D has asymmetrical end portions 11a, 11b tapered with different curvatures R and R respectively.
  • FIGS. 10A to 10D leaf springs shown in FIGS. 10A to 10D.
  • a leaf spring shown in FIG. 10A has both end portions 11a, 11b linearly and symmetrically tapered with respect to the crosswise central line on both upper and lower sides
  • a leaf spring of FIG. 10B is similar to that shown in FIG. 10A except that its both end portions 11a, 11b are asymmetrically tapered
  • a leaf spring of FIG. 10C has both-end portions 11a, 1 lb symmetrically tapered with the same curvature relative to the crosswise central line on both upper and lower sides
  • a leaf spring of FIG. 10D is similar to that shown in FIG. 10C except that its both end portions 11a, 1 lb are asymmetrically tapered.
  • An apparatus for manufacturing leaf springs having a tapered end portion comprising: heating means to heat a metal band, taper forming means for forming a plurality of tapers at portions of the heated metal'band disposed in predetermined intervals, shearing means to divide the tapered metal band into a plurality of leaf spring units having a tapered end, and moving means for moving the metal band to shearing means from the heating means through the taper forming means.
  • An apparatus which further includes center hole forming means for forming a center hole in each of leaf spring units.
  • An apparatus according to' claim 2 which further includes reheating means for reheating the leaf spring unit to be provided with a .center hole.
  • center hole forming means includes a vertically movable punch and a stationary die, the leaf spring units fed between the punch and die.
  • heating means includes a lateral furnace through which the metal band is moved.
  • taper forming means includes a pair of rolling mill rolls at least one of which is vertically movable.
  • An apparatus which further includes control means for automatically moving the rolling mill roll in a vertical direction to form the tapered portion.
  • control means includes a pair of first pinch rolls between the heating means and rolling mill rolls, a first pulse generator connected to the pinch rolls to produce a pulse signal each time a predetermined length of the metal band is passed between the pinch rolls, a logic circuit storing the information on the dimensions of a leaf spring to be formed and receiving the pulse signal from the first pulse generator, so that the pulse signal is processed depending on the preset value of the dimensions of the leaf spring whereby the logic circuit generates an output pulse corresponding to the pulse signal from the first pulse generator, a pulse motor connected to the logic circuit to be driven by the pulse signal from the logic circuit and a screw down mechanism driven by the pulse motor to vertically move one roll of said rolling mill rolls.
  • An apparatus which further includes a pair of second pinch rolls disposed between the rolling mill rolls and shearing means, one of the second pinch rolls being vertically movable in contact with the one side of the leaf spring unit where the taper is the second pinch rolls, the second and third pulse generators respectively connected to the logic circuit in which the pulse signals from the second and third pulse generators are set to be processed depending on the preset value of the dimensions to correct the pulse signal from the logic circuit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Agronomy & Crop Science (AREA)
  • Springs (AREA)
  • Wire Processing (AREA)
  • Metal Rolling (AREA)
US00380580A 1972-07-20 1973-07-19 Apparatus for manufacturing leaf springs having a tapered end portion Expired - Lifetime US3820373A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP47072876A JPS5214822B2 (US06534493-20030318-C00166.png) 1972-07-20 1972-07-20
JP7881373A JPS5311959B2 (US06534493-20030318-C00166.png) 1973-07-12 1973-07-12

Publications (1)

Publication Number Publication Date
US3820373A true US3820373A (en) 1974-06-28

Family

ID=26414012

Family Applications (1)

Application Number Title Priority Date Filing Date
US00380580A Expired - Lifetime US3820373A (en) 1972-07-20 1973-07-19 Apparatus for manufacturing leaf springs having a tapered end portion

Country Status (5)

Country Link
US (1) US3820373A (US06534493-20030318-C00166.png)
DE (1) DE2336459A1 (US06534493-20030318-C00166.png)
FR (1) FR2193680B1 (US06534493-20030318-C00166.png)
GB (1) GB1389626A (US06534493-20030318-C00166.png)
IT (1) IT994104B (US06534493-20030318-C00166.png)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2930005A1 (de) * 1978-07-25 1980-06-19 Aichi Steel Works Ltd Verfahren und einrichtung zum herstellen eines plattenmaterials, das eine gleichmaessige breite und eine laengsweise dickenaenderung hat
US4266418A (en) * 1979-06-15 1981-05-12 Nhk Spring Co., Ltd. Method for manufacturing a taper spring
WO1989000899A1 (en) * 1987-08-04 1989-02-09 Belorussky Politekhnichesky Institut Method and device for making workpieces with a variable longitudinal profile
GB2235147A (en) * 1987-08-04 1991-02-27 Bruss Polt I Method and device for making workpieces with a variable longitudinal profile
US5001918A (en) * 1987-11-04 1991-03-26 Stepanenko Alexandr V Method and apparatus for making blanks of a profile varying lengthwise
US6532638B2 (en) * 1998-04-15 2003-03-18 Robert Bosch Gmbh Method of making flat blade windshield wipers for a motor vehicle with curved flat blade
US20040107757A1 (en) * 2002-10-02 2004-06-10 Benteler Automobiltechnik Gmbh Method of making structural components
US20060222800A1 (en) * 2002-08-29 2006-10-05 Nukorc Pty Ltd Synthetic Cork with Tapered Edge by Heat Shrinking and Method Thereof
CN102218662A (zh) * 2011-06-13 2011-10-19 浙江恒立数控科技股份有限公司 一种金属薄板剪切生产线
CN103056600A (zh) * 2011-10-22 2013-04-24 东风钟祥汽车弹簧有限公司 变截面钢板弹簧利用轧制余热进行多工序加工的方法
US9573432B2 (en) 2013-10-01 2017-02-21 Hendrickson Usa, L.L.C. Leaf spring and method of manufacture thereof having sections with different levels of through hardness
CN106678218A (zh) * 2016-07-15 2017-05-17 安庆安簧汽车零部件有限公司 一片式钢板弹簧及其制造工艺
CN108746353A (zh) * 2018-05-18 2018-11-06 山东汽车弹簧厂淄博有限公司 簧片端部整形系统及整形方法

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4283930A (en) * 1977-12-28 1981-08-18 Aichi Steel Works Limited Roller-dies-processing method and apparatus
US5590556A (en) * 1993-02-11 1997-01-07 Fourie; Eugene Apparatus for the manufacture of a thin metallic strip
US5875672A (en) * 1993-02-11 1999-03-02 Fourie; Eugene Method and apparatus for manufacturing metallic support beams for windscreen wiper blade assemblies
DE19704300B4 (de) * 1997-02-06 2008-07-10 Benteler Ag Verfahren zur Herstellung von Platinen mit unterschiedlichen Dicken
DE19846900C2 (de) 1998-10-12 2000-08-10 Thyssenkrupp Stahl Ag Verfahren und Vorrichtung zum Herstellen eines Metallbandes für abzulängende Tailored Blanks
DE10041280C2 (de) * 2000-08-22 2003-03-06 Muhr & Bender Kg Verfahren und Vorrichtung zum flexiblen Walzen eines Metallbandes
CN107470916A (zh) * 2017-08-03 2017-12-15 常州常发制冷科技有限公司 钢板横剪生产线及应用其的钢板横剪工艺

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4248072A (en) * 1978-07-25 1981-02-03 Aichi Steel Works, Limited Method of and apparatus for producing plate material having uniform width and lengthwise thickness variation
DE2930005A1 (de) * 1978-07-25 1980-06-19 Aichi Steel Works Ltd Verfahren und einrichtung zum herstellen eines plattenmaterials, das eine gleichmaessige breite und eine laengsweise dickenaenderung hat
US4266418A (en) * 1979-06-15 1981-05-12 Nhk Spring Co., Ltd. Method for manufacturing a taper spring
WO1989000899A1 (en) * 1987-08-04 1989-02-09 Belorussky Politekhnichesky Institut Method and device for making workpieces with a variable longitudinal profile
GB2235147A (en) * 1987-08-04 1991-02-27 Bruss Polt I Method and device for making workpieces with a variable longitudinal profile
GB2235147B (en) * 1987-08-04 1991-09-04 Bruss Polt I Method and apparatus for making blanks of a profile varying lengthwise.
US5001918A (en) * 1987-11-04 1991-03-26 Stepanenko Alexandr V Method and apparatus for making blanks of a profile varying lengthwise
US6532638B2 (en) * 1998-04-15 2003-03-18 Robert Bosch Gmbh Method of making flat blade windshield wipers for a motor vehicle with curved flat blade
US20060222800A1 (en) * 2002-08-29 2006-10-05 Nukorc Pty Ltd Synthetic Cork with Tapered Edge by Heat Shrinking and Method Thereof
US20040107757A1 (en) * 2002-10-02 2004-06-10 Benteler Automobiltechnik Gmbh Method of making structural components
US7181948B2 (en) * 2002-10-02 2007-02-27 Benteler Automobil Technik Gmbh Method of making structural components
CN102218662A (zh) * 2011-06-13 2011-10-19 浙江恒立数控科技股份有限公司 一种金属薄板剪切生产线
CN102218662B (zh) * 2011-06-13 2012-09-26 浙江恒立数控科技股份有限公司 一种金属薄板剪切生产线
CN103056600A (zh) * 2011-10-22 2013-04-24 东风钟祥汽车弹簧有限公司 变截面钢板弹簧利用轧制余热进行多工序加工的方法
US9573432B2 (en) 2013-10-01 2017-02-21 Hendrickson Usa, L.L.C. Leaf spring and method of manufacture thereof having sections with different levels of through hardness
US9890440B2 (en) 2013-10-01 2018-02-13 Hendrickson Usa, L.L.C. Leaf spring and method of manufacture thereof having sections with different levels of through hardness
CN106678218A (zh) * 2016-07-15 2017-05-17 安庆安簧汽车零部件有限公司 一片式钢板弹簧及其制造工艺
CN108746353A (zh) * 2018-05-18 2018-11-06 山东汽车弹簧厂淄博有限公司 簧片端部整形系统及整形方法
CN108746353B (zh) * 2018-05-18 2020-04-28 山东汽车弹簧厂淄博有限公司 簧片端部整形系统及整形方法

Also Published As

Publication number Publication date
FR2193680A1 (US06534493-20030318-C00166.png) 1974-02-22
IT994104B (it) 1975-10-20
GB1389626A (en) 1975-04-03
DE2336459A1 (de) 1974-01-31
FR2193680B1 (US06534493-20030318-C00166.png) 1977-05-13

Similar Documents

Publication Publication Date Title
US3820373A (en) Apparatus for manufacturing leaf springs having a tapered end portion
DE2813636C3 (de) Verfahren und Einrichtung zur Herstellung von Profilen aus Metall, vornehmlich von Stahlprofilen
DE2954233C2 (US06534493-20030318-C00166.png)
US3729968A (en) Working of strip metal
EP0728049B1 (en) Hot rolled beam and method of manufacture
JP2005131665A (ja) プレス加工方法
US5001918A (en) Method and apparatus for making blanks of a profile varying lengthwise
US2134366A (en) Production of metal sheets
DE2940473A1 (de) Verfahren und vorrichtung zur herstellung von metallprofilen
US3633398A (en) Making corrugated elastic shims
SU685391A1 (ru) Способ получени круглых листов из широкорулонного материала
US4010524A (en) Apparatus for manufacture of continuous hinge
US2778385A (en) Apparatus and method for forming sinuous wire structural and heat exchange elements
IE38585L (en) Forming metal sections
US3626743A (en) Making corrugated elastic shims
US2366487A (en) Stamping and forming
US5390519A (en) Method for manufacturing long products by press working
DE10150021A1 (de) Verfahren und Anordnung zur Herstellung von Profilen oder Blechformteilen
EP0514099A2 (en) Die-shaping apparatus and process
DE3366446D1 (en) Method for the production of metallic wire, wire obtained by this method and device for carrying out this method
US7334446B1 (en) Method for producing a striplike pre-material made of metal, especially a pre-material which has been profiled into regularly reoccurring sections, and device therefor
US3811309A (en) Method and apparatus for cold drawing or rolling of metal wire rod
US4744502A (en) Process for the production of tri-metallic contact rivets
DD247617A5 (de) Verfahren und vorrichtung zur herstellung von bauteilen aus blech
DE3150578A1 (de) Verfahren, vorrichtung und isolierstab zur herstellung eines waermegedaemmten verbundprofiles fuer fenster, tueren oder dgl.