US3662940A - Method and apparatus for forming cylinders from strip material - Google Patents

Method and apparatus for forming cylinders from strip material Download PDF

Info

Publication number
US3662940A
US3662940A US824206A US3662940DA US3662940A US 3662940 A US3662940 A US 3662940A US 824206 A US824206 A US 824206A US 3662940D A US3662940D A US 3662940DA US 3662940 A US3662940 A US 3662940A
Authority
US
United States
Prior art keywords
mandrel
blank
abutment
welding
periphery
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
US824206A
Other languages
English (en)
Inventor
Christian H Stettler
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.)
CM-MACK INVESTMENTS Inc A CORP OF DE N/K/A GROTNES METALFORMING SYSTEMS Inc
Grotnes Metalforming Systems Inc
Original Assignee
Grotnes Machine Works Inc
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
Application filed by Grotnes Machine Works Inc filed Critical Grotnes Machine Works Inc
Application granted granted Critical
Publication of US3662940A publication Critical patent/US3662940A/en
Assigned to CM-MACK INVESTMENTS, INC., A CORP. OF DE N/K/A GROTNES METALFORMING SYSTEMS, INC. reassignment CM-MACK INVESTMENTS, INC., A CORP. OF DE N/K/A GROTNES METALFORMING SYSTEMS, INC. ASSIGNMENT OF ASSIGNORS INTEREST. AGREEMENT DATED JUNE 27, 1980 Assignors: GROTNES MACHINE WORKS, INC.
Assigned to GROTNES METALFORMING SYSTEMS INC. reassignment GROTNES METALFORMING SYSTEMS INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: GROTNES MACHINE WORKS, INC.
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
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/26—Making other particular articles wheels or the like
    • B21D53/30—Making other particular articles wheels or the like wheel rims
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D5/00—Bending sheet metal along straight lines, e.g. to form simple curves
    • B21D5/14—Bending sheet metal along straight lines, e.g. to form simple curves by passing between rollers
    • B21D5/143—Bending sheet metal along straight lines, e.g. to form simple curves by passing between rollers making use of a mandrel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D51/00—Making hollow objects

Definitions

  • This invention relates to fonning pre-cut blanks of strip material, and in its principal aspect concerns a method and apparatus for fonning such a blank into a cylinder and transferring it to a welding apparatus with its end gap located in a precisely predetermined position for welding.
  • a principal object of the invention is to provide an improved method and apparatus for forming generally cylindrical shapes from pre-cut blanks of sheet material, producing a blank of uniform shape with an end gap positioned at a precise predetermined location relative to the forming apparatus.
  • a further object is to provide an apparatus in which the end gap of a formed blank may be simply and accurately positioned in the jaws of an electric flash welder for joining the ends of the blank by welding. It is intended that no complex mechanism be required to find the gap in the blank after the forming operation, with the blank being instead transferred directly from the forming apparatus to the welding apparatus with the gap in a correct predetermined position for welding at all times.
  • FIG. 1 is a plan view of a cylinder-forming apparatus exemplifying the present invention illustrated in association with ancillary handling equipment;
  • FIG. 2 is a side elevation of the cylinder-forming apparatus and associated welding apparatus of FIG. I;
  • FIG. 3 is an end elevation of the cylinder-forming apparatus of FIG. 2;
  • FIGS. 4-8, inclusive, are partial schematic views of the forming mandrel in the cylinder-forming apparatus of FIG. 3, showing the apparatus in sequential operation;
  • FIG. 9 is an enlarged fragmentary view partly in section illustrating the end elevation of the cylinder forming apparatus in the position substantially as shown in FIG. 3.
  • Apparatus for forming strip material blanks into cylindrical shapes is commonly employed in manufacturing steel automobile wheels.
  • the process of manufacturing such wheels requires that an initially flat blank of pre-cut strip material be formed into a cylinder and welded together to form a continuous ring which then serves as a blank for further forming processes.
  • the ends of the strip are butted together and welded, leaving an upset portion or bead which must be trimmed and smoothed so that the resultant cylinder is substantially uniform about its circumference before it is transferred to other apparatus in which the drop center and flange portions of the rim are formed.
  • Previous forming operations in the manufacture of automobile wheels have used simple coiling apparatus consisting of three spaced rollers through which the strip material is drawn to produce a bend or curl of the required diameter. When a sufficient length of material has been so formed, it is cut off and the resultant formed blank is usually dropped into a hopper or chute for transferring to the subsequent welding operation.
  • Such welders are capable of production rates as high as 500 pieces per hour but the full utilization of this capacity has not been possible heretofore because of the need to individually locate and position the gap in each formed blank before insertion into the welder, often with a resultant bottleneck in production.
  • FIG. 1 a portion of a production line employing a forming machine 10 exemplifying the present invention.
  • Pre-cut flat rectangular blanks 11 of sheet steel are carried in stacks by a conveyor 12 into an unstacking apparatus 13 having magnetic pickup units 14 which lift each individual blank 11 onto a transfer conveyor 15.
  • each blank 11 is carried into the forming machine 10, wherein it is formed by wrapping about a mandrel 16 as described hereinafter.
  • a transfer shuttle 17 carries the formed blank to an electric flash welding machine 18 having pairs of jaws 20 which grip the ends of the formed blank and force them together while passing a heavy electrical current through the joint to fuse the ends.
  • the welded blank is gripped by a gripper 21 on the arm 22 is enabled to grasp the welded blank, withdraw it from the welder l8, and swing it vertically overhead for transfer to a trimmer (not shown) and other subsequent apparatus as required for performing further steps in fabricating the automobile wheel.
  • the cylinder-forming machine exemplifying the present invention is shown in greater detail in FIGS. 2 and 3.
  • the rotatable mandrel 16 is carried for rotation by heavy bearings in a head 25 mounted to a frame 26.
  • a shaft 26 supporting the mandrel 16 protrudes through the rear of the head 25 and attaches to a gear 27 which is driven by a rotary actuator 28 through another gear 29.
  • the rotary actuator 28 is of the rack and pinion type which is effective to reciprocate the gear 29 through of rotation.
  • the ratio between the gears 27, 29 is 2:1, thereby reciprocating the gear 27 and the mandrel 16 over 360 of rotation, concluding in a predetermined end position.
  • the elements of the forming apparatus 10 which are effective to form the incoming blank 11 of strip material into a generally cylindrical shape are best seen in FIG. 3, and in FIGS. 4-8 wherein the sequence of forming operations is illustrated schematically.
  • the incoming blank 11 is fed by the feeding means 15 to a first guide means consisting of a transverse roller 30 fixed to the frame 26 of the machine.
  • the roller 30 is spaced from the periphery of the mandrel 16 so that a blank 11 resting on the upper surface of the roller 30 in a horizontal position is presented with its upper surface tangent to the mandrel 16.
  • the blank 11 is held in a clamp consisting of a pair of opposed jaws 31, 32 (FIG. 9) wherein it is first positioned against an abutment 33. Both the jaws 31, 32 and the abutment 33 are carried by the mandrel 16 and rotate with it through 360 under the power of the rotary actuator 28.
  • the jaw 32 is fixed, being carried by a back-up support 35 which is cantilevered forward from the rear of the mandrel 16.
  • the jaw 31 is movable in a radial direction by means of a hydraulic piston 36 carried within the mandrel 16 itself. Pressure fluid is introduced through a port 37 connected at the rear through a flexible hose (not shown) to a suitable control and supply source of pressure fluid. Because the mandrel 16 does not continuously rotate but only reciprocates through 360 from starting to end positions, no rotary connection is necessary.
  • a return spring 38 causes the piston 36 and movable jaw 31 to retract when the pressure from the port 37 is relieved.
  • a blank 11 is fed in over the guide roller 30 into the jaws 31, 32, where it is securely clamped by admitting pressure fluid to the hydraulic piston 36. It will be observed that the faces of the jaws 31, 32 are planar and substantially parallel to the plane of an incoming blank 11.
  • the mandrel rotates (counterclockwise as seen in the figures) to draw blank 11 forward over the guide roller 30 and wrap it around the periphery of the mandrel 16 (FIG.
  • the mandrel 16 has a flat surface on either side of the abutment 33, with one side consisting ofthe movable jaw 31 when in the clamped position against a blank 1 1.
  • the forming process is then finished by the introduction of a flat-ended ram 43 into the space between the second guide roller 40 and the abutment 33 and against the flat surface of the mandrel 16.
  • the ram 43 is carried by a pair of links 45, 46 and is urged against the mandrel 16 by a hydraulic cylinder 47.
  • the grippers 50 are actuated by pneumatic bellows 51 on opposite sides of a pick-up yoke 52 carried on a trolley 53.
  • the trolley 53 runs on rails 54 above the machine overhanging the mandrel 16 and parallel to the axis of mandrel rotation.
  • the trolley 53 is reciprocated by another rotary actuator 56 turning a crank arm 57 through 180 of movement, moving back and forth on the rails 54 to transfer the pick-up yoke 52 and the formed blank 11 carried by the grippers 50 into the jaws 20 of the welding machine 18.
  • a link 58 connects the crank arm 57 to a pair of arms 60 which are connected through further links 61 to the trolley 53.
  • FIG. 9 Removal of the formed blank 11 from the mandrel 16 is facilitated by providing a projecting finger 63 (FIG. 9) on each of the grippers 50 which, when the mandrel 16 is in its end position, travels in a corresponding axial groove 64 in the side of the mandrel.
  • the fingers 63 are located at the rear of the grippers 50 so that the formed blank 11 is picked up from behind and carried outward in the grippers 50 on its way to the welding jaws 20.
  • the gaps in succeeding formed blanks are substantially identical in dimension and angular position due to the action of the various forming members including the mandrel l6, guide rollers 30, 40 and ram 42.
  • the ends of each formed blank are precisely located with respect to the abutment 33 which serves as a spacer to assure a constant gap size from one formed blank to the next. While the details of the welding machine 18 are not shown, for the purposes of understanding the present invention it is only necessary to explain that the welding jaws 20 are disposed in two adjoining pairs to clamp the ends of the formed blank 1 l on each side of the gap. Once in the jaws 20 of the welding machine 18, the ends of the formed blank are forced together under a heavy electrical current which causes the metal within the gap to fuse under heat and pressure. This technique of flash or butt welding is well known and need not be described further.
  • the swingover transfer arm 22 with its grippers 21 takes hold of the welded blank and transfers it over to further machines (not shown) which complete the forming process by trimming the upset bead from the weld and plannishing the remaining ridge by rolling the bead down flat.
  • the mandrel 16 With the pick-up yoke extended to carry the formed blank 1 l to the welding machine 18, the mandrel 16 is free to return to its starting position by reverse actuation of the rotary actuator 28.
  • the second guide roller 40 and ram 42 are first retracted to allow the back-up frame of the mandrel 16 to clear as it returns to its starting position.
  • the hydraulic pressure behind the piston 36 is released, the movable jaw 31 returns to its open position, and the mandrel 16 is ready to receive the next succeeding blank while the pick-up yoke 52 and the grippers 50 (now retracted) are returned to the starting position for the next forming operation.
  • Apparatus for forming blanks of strip material preparatory to welding the ends thereof with welding means comprising in combination,
  • a mandrel mounted at one end for rotation, said mandrel carrying a radially outwardly extending locating abutment and clamping means on one side of the abutment for gripping a leading end of a blank positioned against the abutment and mandrel periphery,
  • first guide means spaced from the mandrel periphery and parallel to the axis of mandrel rotation, said first guide means being aligned with the mandrel and abutment in a starting position for positioning the leading end of an unforrned blank against the mandrel periphery, said abutment, and within the clamping means,
  • second guide means parallel to the axis of mandrel rotation and shiftable toward the mandrel periphery for forming a trailing end of the blank against the mandrel on the opposite side of the abutment from the clamping means when the blank has cleared the first guide means and the mandrel and abutment are at said predetermined end position
  • ram means shiftable toward said mandrel on the opposite side of said abutment for pressing said trailing end of the blank against said mandrel periphery and said opposite side of said abutment and means for transferring said formed blank from the mandrel to said welding means with the blank in said predetermined position and welding said blank.
  • the first guide means includes a fixed guide roller
  • the second guide means includes a shiftable guide roller and power means for shifting the shiftable guide roller toward the mandrel
  • the mandrel is rotatable through 360 from the starting position to the predetermined end position.
  • Apparatus as defined in claim 1 including gripping means for seizing a formed blank carried by the mandrel with the leading and trailing edges of the formed blank defining a gap having a predetermined position when the mandrel is in its predetermined end position, linear transfer means for transporting the gripping means to withdraw the formed blank axially from the mandrel, and welding means for receiving the formed blank from the transfer means with said gap in said predetermined position.
  • the welding means includes opposed gripping jaws for seizing the ends of a formed blank adjacent on each side of said gap, with said jaws being positioned linearly opposite the ends of a formed blank carried by the mandrel when the mandrel is in its predetermined end position.
  • shifting ram means to press the trailing edge end of the blank into engagement with the mandrel periphery adjacent the opposite side of said abutment
  • removing the formed blank from the mandrel includes the steps of gripping the periphery of the formed blank
  • Apparatus for forming blanks of strip material preparatory to welding the ends thereof with welding means comprising in combination,
  • a mandrel mounted at one end for rotation, said mandrel carrying a radially extending locating abutment and clamping means on one side of the abutment for gripping a leading end of a blank positioned against the abutment and mandrel periphery,
  • first guide means spaced from the mandrel periphery and parallel to the axis of mandrel rotation, said first guide means being aligned with the mandrel and abutment in a starting position for positioning the leading end of an unformed blank within the clamping means
  • second guide means parallel to the axis of mandrel rotation and shiftable toward the mandrel periphery for forming a trailing end of the blank against the mandrel on the opposite side of the abutment from the clamping means when the mandrel and abutment are at said predetermined end position
  • said mandrel surface including flat coplanar surfaces on opposite sides of the abutment
  • the clamping means including a pair of planar jaws
  • said second guide means further including a flat-ended ram shiftable toward the fiat mandrel surface adjacent the abutment on the opposite side from the clamping means when the mandrel is in its predetermined end position,

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Butt Welding And Welding Of Specific Article (AREA)
US824206A 1969-05-13 1969-05-13 Method and apparatus for forming cylinders from strip material Expired - Lifetime US3662940A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US82420669A 1969-05-13 1969-05-13

Publications (1)

Publication Number Publication Date
US3662940A true US3662940A (en) 1972-05-16

Family

ID=25240862

Family Applications (1)

Application Number Title Priority Date Filing Date
US824206A Expired - Lifetime US3662940A (en) 1969-05-13 1969-05-13 Method and apparatus for forming cylinders from strip material

Country Status (6)

Country Link
US (1) US3662940A (de)
JP (1) JPS501352B1 (de)
DE (1) DE2022424C3 (de)
FR (1) FR2042610B1 (de)
GB (1) GB1285135A (de)
SE (1) SE374285B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015003276A1 (de) * 2013-07-08 2015-01-15 Andritz Soutec Ag Verfahren zur herstellung von ringförmigen teilen und eine anwendung des verfahrens

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2243293C2 (de) * 1972-09-02 1981-10-01 Lang, Ludwig, 6120 Michelstadt Vorrichtung zum Biegen von strangförmigen Werkstücken
US3934324A (en) * 1975-02-14 1976-01-27 Grotnes Machine Works, Inc. Method and apparatus for forming automotive wheel rim blanks
DE3028956A1 (de) * 1980-07-30 1982-03-04 Späth GmbH & Co KG, 7760 Radolfzell Verfahren zur herstellung von rundkoerpern
DE3037614A1 (de) * 1980-10-04 1982-06-03 Th. Kieserling & Albrecht Gmbh & Co, 5650 Solingen Anlage zur herstellung von felgenrohlingen
DE3404641A1 (de) * 1983-06-09 1984-12-13 Späth GmbH & Co KG, 7760 Radolfzell Verfahren und vorrichtung zur herstellung von aus metallprofilen bestehenden rundkoerpern, insbesondere von radfelgen fuer kraftfahrzeuge
DE102004046687B3 (de) * 2004-09-24 2006-06-01 Thyssenkrupp Steel Ag Verfahren und Vorrichtung zur Herstellung eines längsnahtgeschweißten Hohlprofils
RU2569864C2 (ru) * 2014-03-25 2015-11-27 Общество с ограниченной ответственностью "Аэростарт" Листогибочный станок и способ получения деталей с увеличивающимся радиусом кривизны

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2675849A (en) * 1949-08-26 1954-04-20 Budd Co Machine for coiling wheel rim stock or the like
US2857871A (en) * 1953-12-08 1958-10-28 Western Electric Co System for maintaining a straight seam in the manufacture of tubing
US2949087A (en) * 1953-11-12 1960-08-16 Bogner Peter Apparatus for making cans
US3048202A (en) * 1958-11-24 1962-08-07 Wedge Protectors Inc Ring rolling machine
US3083751A (en) * 1958-07-01 1963-04-02 Yoder Co Ring coiling and cut-off machine
US3096807A (en) * 1960-09-20 1963-07-09 Cryil Bath Company Metal forming machine and auxiliary fixture and combination thereof
US3148721A (en) * 1960-08-17 1964-09-15 Cyril Bath Co Stock saving side grip head for stretch forming machines
US3285490A (en) * 1963-06-25 1966-11-15 Wallace Expanding Machines Apparatus for making tubular members
US3360178A (en) * 1962-07-02 1967-12-26 Taylor Winfield Corp Apparatus for making metal rings
US3423003A (en) * 1965-09-28 1969-01-21 Tube & Pipe Ind Proprietary Lt Method and means for the manufacture of spiral piping
US3425118A (en) * 1964-01-24 1969-02-04 Caribbean Holdings Ltd Apparatus and method of making elongated vessels,containers and tubular members
US3484576A (en) * 1968-01-03 1969-12-16 Sterling Packing & Gasket Co Machine for making spirally wound composite gaskets

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1798439A (en) * 1927-08-01 1931-03-31 Seaholm Martin August Machine for forming can bodies
US2737707A (en) * 1950-05-27 1956-03-13 Clevite Corp Method and apparatus for forming flanged bearings

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2675849A (en) * 1949-08-26 1954-04-20 Budd Co Machine for coiling wheel rim stock or the like
US2949087A (en) * 1953-11-12 1960-08-16 Bogner Peter Apparatus for making cans
US2857871A (en) * 1953-12-08 1958-10-28 Western Electric Co System for maintaining a straight seam in the manufacture of tubing
US3083751A (en) * 1958-07-01 1963-04-02 Yoder Co Ring coiling and cut-off machine
US3048202A (en) * 1958-11-24 1962-08-07 Wedge Protectors Inc Ring rolling machine
US3148721A (en) * 1960-08-17 1964-09-15 Cyril Bath Co Stock saving side grip head for stretch forming machines
US3096807A (en) * 1960-09-20 1963-07-09 Cryil Bath Company Metal forming machine and auxiliary fixture and combination thereof
US3360178A (en) * 1962-07-02 1967-12-26 Taylor Winfield Corp Apparatus for making metal rings
US3285490A (en) * 1963-06-25 1966-11-15 Wallace Expanding Machines Apparatus for making tubular members
US3425118A (en) * 1964-01-24 1969-02-04 Caribbean Holdings Ltd Apparatus and method of making elongated vessels,containers and tubular members
US3423003A (en) * 1965-09-28 1969-01-21 Tube & Pipe Ind Proprietary Lt Method and means for the manufacture of spiral piping
US3484576A (en) * 1968-01-03 1969-12-16 Sterling Packing & Gasket Co Machine for making spirally wound composite gaskets

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015003276A1 (de) * 2013-07-08 2015-01-15 Andritz Soutec Ag Verfahren zur herstellung von ringförmigen teilen und eine anwendung des verfahrens
CN105555430A (zh) * 2013-07-08 2016-05-04 安德里茨索泰克股份公司 用于制造环形件的方法以及所述方法的使用

Also Published As

Publication number Publication date
DE2022424A1 (de) 1970-12-03
DE2022424B2 (de) 1974-11-07
FR2042610A1 (de) 1971-02-12
JPS501352B1 (de) 1975-01-17
SE374285B (sv) 1975-03-03
GB1285135A (en) 1972-08-09
DE2022424C3 (de) 1975-06-12
FR2042610B1 (de) 1974-02-22

Similar Documents

Publication Publication Date Title
US20050247368A1 (en) Machine for the formation of metal mesh and relative method
US3662940A (en) Method and apparatus for forming cylinders from strip material
CN111657604A (zh) 一种立式折叠口罩全自动化生产设备及工艺
US4082935A (en) Apparatus and method for making wheel rim blanks and the like
US2949136A (en) Apparatus for the automatic production of closed loops of wire from wire stock
JP2834803B2 (ja) フィラー付きビードの成形装置
JP2648369B2 (ja) バレル形コイルバネの成形方法及びその装置
JPH0636369B2 (ja) 電極集成体を巻装する方法
CN212590483U (zh) 一种立式折叠口罩全自动化生产设备
US2678620A (en) Process and apparatus for making tanks and the like
GB1262976A (en) Improvements in or relating to the manufacture of welded rim blanks for disc wheels
EP0278737A1 (de) Verfahren und Einrichtung zum Formen und Schweissen von Ringen
US3592103A (en) Apparatus for removing material from a workpiece
JP3401496B2 (ja) 中空成形体ブランクを移送するための方法および装置
JP3922730B2 (ja) ディスクホィールリムのアプセットバット溶接方法
GB1597199A (en) Device for the application of elastomeric fillers on bead cores of pneumatic tyres
US3862563A (en) Truck rim forming apparatus
JPH051733B2 (de)
US8276635B2 (en) Machines and methods for manufacturing of an object closed onto itself
SU789262A1 (ru) Устройство дл сборки и дуговой сварки металлоконструкций
US3184947A (en) Stud forming and transfer mechanisms
CN220547720U (zh) 一种定长自定卷料机
US3254681A (en) Reinforcing cage apparatus and method of making
SU965687A2 (ru) Устройство дл сборки и дуговой сварки металлоконструкций
WO2023152784A1 (en) Apparatus for forming electrical energy storage devices

Legal Events

Date Code Title Description
AS Assignment

Owner name: GROTNES METALFORMING SYSTEMS INC., 5454 NORTH WOLC

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GROTNES MACHINE WORKS, INC.;REEL/FRAME:003827/0312

Effective date: 19810119