US3668916A - Drawing of metal tubing - Google Patents
Drawing of metal tubing Download PDFInfo
- Publication number
- US3668916A US3668916A US3979A US3668916DA US3668916A US 3668916 A US3668916 A US 3668916A US 3979 A US3979 A US 3979A US 3668916D A US3668916D A US 3668916DA US 3668916 A US3668916 A US 3668916A
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- US
- United States
- Prior art keywords
- tube
- die
- wall thickness
- drawn
- velocity
- 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.)
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C1/00—Manufacture of metal sheets, metal wire, metal rods, metal tubes by drawing
- B21C1/16—Metal drawing by machines or apparatus in which the drawing action is effected by other means than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, bars, or tubes
- B21C1/27—Carriages; Drives
- B21C1/30—Drives, e.g. carriage-traversing mechanisms; Driving elements, e.g. drawing chains; Controlling the drive
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C51/00—Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F
Definitions
- the elongation of the tube in the draw die is determined by I the equation I r/ F z/ i I where .4 and A are, respectively, the cross-sectionalareas of the tube before and after drawing, and V is the velocity of the tube leaving the die and V is the velocity of the tube entering the die.
Abstract
The method of controlling the wall thickness of a drawn metal tube by applying forces on the tube on opposite sides of the die whereby the tube leaves the die at a higher velocity than the velocity of the tube entering the die, and relating the velocities in a ratio to produce the desired wall thickness of the drawn tube.
Description
United States Patent Ledebur [151 3,668,916 [451 June 13, 1972 [54] DRAWING OF METAL TUBING [72] Inventor: Harry C. Ledebur, Cranfield, Ohio [73] Assignee: Wean Industries, Inc.
[22] Filed: Jan. 19, 1970.
[2]] Appl. No.: 3,979
52 U.S.Cl. ..72/274, 72/284 51 m.c|......- ..B2lcl/00 5s FleldofSearch ..72/288,287,283,284,274
[56] References Cited UNITED STATES PATENTS 3,238,752 3/1966 Dilling ..72/2s3 3,572,078 3/1971 Kennedyet al ..72/l94 WALL t.
counuuous DRAW UNIT ENTERING TUBE DIAM- d,
CONTROLLED VELOCITY V.
Andrews et al ..72/284 Russell Primary Examiner-Charles W. Lanham Assistant Eraminer--Michael J. Keenan AttorneyMichael Williams [5 7] ABSTRACT The method of controlling the wall thickness of a drawn metal tube by applying forces on the tube on opposite sides of the die whereby the tube leaves the die at a higher velocity than the velocity of the tube entering the die, and relating the velocities in a ratio to produce the desired wall thickness of the drawn tube.
ZJA 17 PULL FORCE F DRAWING OF METAL TUBING BACKGROUND AND SUMMARY Heretofore, as far as I am aware, the wall thickness of a tube was controlled'during drawing operations by means of a plug disposed within the tube substantially in line with the draw die opening. The plug was either anchored on the end of a rod, or of the floating type wherein the plug is retained inside the tube in its proper position relative to the die by a shoulder on the plug bearing against the inside wall of the tube as the latter is reduced in diameter by the die.
In the case of the anchored plug the length of tube to be reduced was restricted to a practical length of the anchoring rod. This restriction was overcome by use of the floating plug, but plug life and proper lubrication of the floating plug presented problems. Perhaps the most severe limitation to use of a floating plug resulted in the drawing of welded tubes because the internal bead of a welded tube would score the plug and thereby unduly limit its life. Trimming of the internal bead of a welded tube not only necessitated an additional operation but also required caution. to prevent the bead trimmings from reaching the plug.
My invention eliminates the need for an internal plug in the drawing of tubing and thus provides many advantages over the prior art; For example, my invention makes it possible to draw tubing of long lengths, and eliminates the need for a plug anchor rod in the case of the fixed plug, or the need for plug lubrication and inspection, in the case of a floating plug. The tube drawing apparatus of my invention may be disposed in line with a tube welding mill to obtain higher production and closer O.D. tolerance and in such case the internal weld bead may be either trimmed or untrimmed depending upon the requirement of the finished product. Further, with this arrangement small diameter tubing of accurate diameter and wall thickness may be produced from a welded tube of larger diameter which is easier to weld and which facilitates trimming of the internal bead when required. Also, roll cost may be minimized by enabling production of various finished tube sizes from the same welded tube size.
My invention also makes it possible to efiect multiple reduction of long tubes through a series of dies and continuous draw units in line, in which case the wall thickness of the tube exit ing from each'die is controlled by the relative speed of the succeeding continuous draw unitv Such arrangement may be close-coupled, with a minimum of space between succeeding units. This is a decided advantage over draw units which require an internal plug to control the wall thickness at each die since the requirement of matching the speed of the draw units in the latter case becomes difiicult and may require considerably more space to the units.
My invention also makes it possible to draw long tubes at elevated temperatures since it is extremely difficult to properly cool and lubricate an internal plug under such conditions. Accordingly, it is the principal object of my invention to provide a method of controlling the wall thickness of a drawn tube, without the use of an internal plug.
allow looping of the tubing between DESCRIPTION OF THE DRAWING In the drawing accompanying this description and forming a part of this specification, there is shown, for purposes of illustration, an embodiment which my invention may assume, and
in this drawing the single figure is a schematic representation of such embodiment.
I DESCRIPT ION OF PREFERRED EMBODIMENT trolled by applying forces to the tube on opposite sides of the die whereby the tube leaves the die at a higher velocity than the velocity of the tube entering the die.
Any suitable means may be utilized to apply the forces to the tube, but I prefer to employ continuous draw units in preference to pinch rolls since the transport diameter of such draw units is more constant.
The drawing shows draw units l4, 15, such as caterpillar drives, on opposite sides of the die, each unit comprising a pair of endless belts or chains 16 on which traction lugs 17 are supported. The belts are driven in any suitable manner in the direction of the arrows l8, and the lugs 17 on respective pairs of belts cooperate to form an elongated rectilinear pass 19 in which the tube is gripped.
Any suitable means, such as variable speed drives (not shown) may be used to control the velocity of the units 14, 15, so that the velocity of one or both may be changed at will. In accordance with my invention, the unit 15 is driven at a higher velocity than the velocity of the unit 14.
I have disclovered that the wall thickness of the drawn tube may be accurately controlled, without use of an internal plug, by controlling the ratio of the velocities of the units 14, 15, and thus the velocities of the tube entering and leaving the die.
My discovery may be mathematically proven in the following manner:
The cross-sectional area A, of the tube prior to drawing is equal to 1rt,(d,-t,), where d, and t, are, respectively, the outside diameter and wall thickness of the tube prior to drawin g.
The cross-sectional area A of the tube after drawing is equal to m m -t where d and are, respectively, the outside diameter and wall thickness of the tube after drawing.
The elongation of the tube in the draw die is determined by I the equation I r/ F z/ i I where .4 and A are, respectively, the cross-sectionalareas of the tube before and after drawing, and V is the velocity of the tube leaving the die and V is the velocity of the tube entering the die.
From the above equations, the following mathematical equation may be evolved:
Thus having given values of 11,, d," and 2,, the wall thickness 1 of the drawn tube is determined soley by the ratio V,/V Therefore, the wall thickness of the drawn tube may be established by proper selection of the relative speeds of the draw units l4, 15.
Since the velocity of the draw unit 15 is higher than that of the unit 14, a pull force F, in the direction of the arrow 20 will be exerted on the tube leaving the die, whereas a pull force F, in the opposite direction (arrow 21) will be exerted on the tube as it enters the die 11. Thus, a stretching force is applied to the tube which reduces its wall thickness in direct relation to the ratio V /V It will be understood that the reduction in wall thickness of the drawn tubing will be limited by the maximum allowable longitudinal stress in the die.
I claim:
1. In the art of drawing a metal tube through a die without the use of a mandrel to reduce the outside diameter of the tube, the improved method of controlling the wall thickness of the drawn tube to a desired dimension, which comprises:
controlling tube movement by applying forces to the tube on opposite sides of the die whereby the tube leaves said die at a higher velocity than the velocity of the tube entering said die, and
relating the entering and leaving velocities of the tube in a t i t t t
Claims (2)
1. In the art of drawing a metal tube through a die without the use of a mandrel to reduce the outside diameter of the tube, the improved method of controlling the wall thickness of the drawn tube to a desired dimension, which comprises: controlling tube movement by applying forces to the tube on opposite sides of the die whereby the tube leaves said die at a higher velocity than the velocity of the tube entering said die, and relating the entering and leaving velocities of the tube in a ratio solely predetermined by the outside diameter and wall thickness of the tube before drawing and the desired wall thickness and reduced outside diameter of the drawn tube.
2. The method of claim 1 wherein the ratio of the entering and leaving velocities of the tube are predetermined in accordance with the mathematical equation t2(d2-t2) t1(d1-t1) (V1/V2) where t2 is the desired wall thickness of the drawn tube, d2 is the reduced outside diameter of the drawn tube, and d1 and t1 are, respectively, the outside diameter and wall thickness of the tube before being drawn.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US397970A | 1970-01-19 | 1970-01-19 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3668916A true US3668916A (en) | 1972-06-13 |
Family
ID=21708514
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US3979A Expired - Lifetime US3668916A (en) | 1970-01-19 | 1970-01-19 | Drawing of metal tubing |
Country Status (1)
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US (1) | US3668916A (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3756062A (en) * | 1971-06-21 | 1973-09-04 | Amerola Prod Corp | High-velocity swaging |
US3812702A (en) * | 1971-06-26 | 1974-05-28 | H Benteler | Multi-pass method and apparatus for cold-drawing of metallic tubes |
FR2558080A1 (en) * | 1984-01-17 | 1985-07-19 | Gp Konstruk | Method for drawing products with countertension, drawing bench (bed) for implementing the said method and products treated in accordance with the said method |
DE3612805A1 (en) * | 1986-04-16 | 1987-10-22 | Kabelmetal Electro Gmbh | METHOD FOR CORRECTING THE WALL THICKNESS WHEN DRAWING HOLLOW CYLINDER-SHAPED METALLIC GOODS |
US4857247A (en) * | 1986-08-18 | 1989-08-15 | Technicon Instruments Corporation | Method for drawing thermoplastic tubing |
US5921128A (en) * | 1996-12-17 | 1999-07-13 | Mannesmann Aktiengesellschaft | Method and apparatus for cold rolling tubes |
US6298542B1 (en) * | 1998-04-17 | 2001-10-09 | Nexans | Process for the manufacture of an optical cable |
EP2368648A1 (en) * | 2010-03-26 | 2011-09-28 | BL Chemie GmbH & Co. KG | Method for reforming rods, profiles and/or tubes with a pull force and a counteracting force |
EP2842647A1 (en) * | 2013-08-30 | 2015-03-04 | FRO - Air Liquide Welding Italia S.P.A. | Method for manufacturing cored wire with elongation control |
US9638357B1 (en) | 2015-06-24 | 2017-05-02 | Omax Corporation | Mechanical processing of high aspect ratio metallic tubing and related technology |
US20220088659A1 (en) * | 2019-01-04 | 2022-03-24 | Sms Group Gmbh | Method for changing the callibration range of a drawing chain, comprising chain links, of a caterpillar-track drawing machine, and caterpillar-track drawing machine |
US11904494B2 (en) | 2020-03-30 | 2024-02-20 | Hypertherm, Inc. | Cylinder for a liquid jet pump with multi-functional interfacing longitudinal ends |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2108790A (en) * | 1934-05-09 | 1938-02-22 | Sidney D Inscho | Tube drawing apparatus |
US2159561A (en) * | 1935-01-16 | 1939-05-23 | Republic Steel Corp | Method of and apparatus for removing scale from and sizing rods and the like |
US2717072A (en) * | 1951-02-12 | 1955-09-06 | Calumet & Hecla | Stock drawing apparatus |
US3013652A (en) * | 1959-02-18 | 1961-12-19 | Amaconda American Brass Compan | Tube drawing apparatus |
US3238752A (en) * | 1964-10-12 | 1966-03-08 | Titanium Metals Corp | Tube reducing apparatus |
US3572078A (en) * | 1967-06-29 | 1971-03-23 | North American Rockwell | Variable orifice, zero friction draw die |
-
1970
- 1970-01-19 US US3979A patent/US3668916A/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2108790A (en) * | 1934-05-09 | 1938-02-22 | Sidney D Inscho | Tube drawing apparatus |
US2159561A (en) * | 1935-01-16 | 1939-05-23 | Republic Steel Corp | Method of and apparatus for removing scale from and sizing rods and the like |
US2717072A (en) * | 1951-02-12 | 1955-09-06 | Calumet & Hecla | Stock drawing apparatus |
US3013652A (en) * | 1959-02-18 | 1961-12-19 | Amaconda American Brass Compan | Tube drawing apparatus |
US3238752A (en) * | 1964-10-12 | 1966-03-08 | Titanium Metals Corp | Tube reducing apparatus |
US3572078A (en) * | 1967-06-29 | 1971-03-23 | North American Rockwell | Variable orifice, zero friction draw die |
Cited By (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3756062A (en) * | 1971-06-21 | 1973-09-04 | Amerola Prod Corp | High-velocity swaging |
US3812702A (en) * | 1971-06-26 | 1974-05-28 | H Benteler | Multi-pass method and apparatus for cold-drawing of metallic tubes |
FR2558080A1 (en) * | 1984-01-17 | 1985-07-19 | Gp Konstruk | Method for drawing products with countertension, drawing bench (bed) for implementing the said method and products treated in accordance with the said method |
DE3612805A1 (en) * | 1986-04-16 | 1987-10-22 | Kabelmetal Electro Gmbh | METHOD FOR CORRECTING THE WALL THICKNESS WHEN DRAWING HOLLOW CYLINDER-SHAPED METALLIC GOODS |
US4857247A (en) * | 1986-08-18 | 1989-08-15 | Technicon Instruments Corporation | Method for drawing thermoplastic tubing |
US5921128A (en) * | 1996-12-17 | 1999-07-13 | Mannesmann Aktiengesellschaft | Method and apparatus for cold rolling tubes |
US6298542B1 (en) * | 1998-04-17 | 2001-10-09 | Nexans | Process for the manufacture of an optical cable |
EP2368648A1 (en) * | 2010-03-26 | 2011-09-28 | BL Chemie GmbH & Co. KG | Method for reforming rods, profiles and/or tubes with a pull force and a counteracting force |
EP2842647A1 (en) * | 2013-08-30 | 2015-03-04 | FRO - Air Liquide Welding Italia S.P.A. | Method for manufacturing cored wire with elongation control |
US9638357B1 (en) | 2015-06-24 | 2017-05-02 | Omax Corporation | Mechanical processing of high aspect ratio metallic tubing and related technology |
US9976675B1 (en) | 2015-06-24 | 2018-05-22 | Omax Corporation | Mechanical processing of high aspect ratio metallic tubing and related technology |
US11125360B2 (en) | 2015-06-24 | 2021-09-21 | Omax Corporation | Mechanical processing of high aspect ratio metallic tubing and related technology |
US20220088659A1 (en) * | 2019-01-04 | 2022-03-24 | Sms Group Gmbh | Method for changing the callibration range of a drawing chain, comprising chain links, of a caterpillar-track drawing machine, and caterpillar-track drawing machine |
US11786950B2 (en) * | 2019-01-04 | 2023-10-17 | Sms Group Gmbh | Method for changing the callibration range of a drawing chain, comprising chain links, of a caterpillar-track drawing machine, and caterpillar-track drawing machine |
US11904494B2 (en) | 2020-03-30 | 2024-02-20 | Hypertherm, Inc. | Cylinder for a liquid jet pump with multi-functional interfacing longitudinal ends |
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