CN1198111A - Method of rolling deformed bar and roll for deformed bar - Google Patents

Method of rolling deformed bar and roll for deformed bar Download PDF

Info

Publication number
CN1198111A
CN1198111A CN96197278A CN96197278A CN1198111A CN 1198111 A CN1198111 A CN 1198111A CN 96197278 A CN96197278 A CN 96197278A CN 96197278 A CN96197278 A CN 96197278A CN 1198111 A CN1198111 A CN 1198111A
Authority
CN
China
Prior art keywords
groove
mentioned
roll
kerve
deformed bar
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.)
Pending
Application number
CN96197278A
Other languages
Chinese (zh)
Inventor
武田了
金堂秀范
桜井智康
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.)
JFE Steel Corp
Original Assignee
Kawasaki Steel Corp
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 Kawasaki Steel Corp filed Critical Kawasaki Steel Corp
Publication of CN1198111A publication Critical patent/CN1198111A/en
Pending 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
    • B21B27/00—Rolls, roll alloys or roll fabrication; Lubricating, cooling or heating rolls while in use
    • B21B27/02—Shape or construction of rolls
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section
    • B21B1/163—Rolling or cold-forming of concrete reinforcement bars or wire ; Rolls therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/16—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling wire rods, bars, merchant bars, rounds wire or material of like small cross-section

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Geometry (AREA)
  • Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
  • Metal Rolling (AREA)

Abstract

A deformed bar having knots and four ribs on its surface is produced by performing the final finish rolling by means of a two-roll rolling mill. Rolls (R1, R2) of the two-roll rolling mill have a peripheral groove (3), knot grooves (2) and a bottom groove (1). The peripheral groove (3) is substantially semi-circular in cross section, and is provided over the whole peripheral surface of the roll. The knot grooves (2) are made in the groove surfaces of the peripheral groove (3) and have a predetermined width so as to cross the peripheral groove (3). The cross section of the bottom groove (1) is an isosceles trapezoid and the groove (1) is provided along the center line of the peripheral groove (3) over the whole circumference of the peripheral groove.

Description

The milling method of deformed bar and roll for deformed bar
Technical field
This invention relates in order to obtain the milling method as the deformed bar of reinforcing bar use etc., particularly relate to utilize 2 rolled steel machines stably to obtain to have the method and employed roll in the method for the deformed bar of 4 ribs that extend along longitudinally.
Background technology
Deformed bar before, general form as shown in Figure 6.In Fig. 6, (a) be side view, (b) be the X-X cutaway view of (a).This deformed bar 5 on the periphery of its pole material, is shown uniformly-spaced formation along a plurality of protuberances (joint) 12 that circumferencial direction extends greatly at longitudinally.In addition, 2 protuberances (rib) 4 that extend along the longitudinally circumferencial direction that is formed at the section circle, 180 ° the position that is separated by.
Such deformed bar 5 is on the final finishing mill of the continuous hot-rolling equipment that many 2 rolled steel machine arranged in series are got up, and uses Fig. 7 and planishing roll R1, R2 shown in Figure 8, makes by rolling method.
Fig. 7 is the front view of the configuration of expression two planishing rolls, and Fig. 8 (a) is the expanded view of roll circumference face, (b) is the Y-Y cutaway view of (a).By these figure as can be known, be roughly semicircular all grooves 3 along whole circumference direction formation section on two planishing roll R1, the R2 of pass forming final fine finishining.In addition, on the groove face of all grooves 3, form and the vertical joint groove 2 of this groove 3 in week.
Then, make by the upstream side roll train be rolled into section be oval blank S by two planishing roll R1, the formed pass of R2, can form on the periphery of pole material with save groove 2 corresponding joints 12 and blank S by from the formed rib 4 of the joint flash that comes out between roll R1, R2.
In addition, the joint of deformed bar also has the situation with respect to the longitudinally tilted configuration.At this moment, as shown in Figure 9, the joint groove 2 of planishing roll R is with respect to circumferencial direction inclination predetermined angular α.In Fig. 9, (a) be the expanded view of the periphery of planishing roll R, (b) be its Z-Z cutaway view.At this moment, the rib of the deformed bar that is obtained is also just by formed 2 from the joint flash that comes out between planishing roll R.
In recent years, be everlasting and such deformed bar carried out bending on the processing equipment.In this case, if having only 2 ribs, then on the feeder of processing equipment and supporting arrangement, be difficult to stably support the surface of deformed bar.Therefore, seeking roughly equally spaced to have the deformed bar of 4 ribs at circumferencial direction.In addition, the steel bar end that deformed bar is used as armored concrete uses, if when 4 ribs are arranged, also has the advantage that improves with concrete adhesive force.
But the manufacturing technology with deformed bar of 4 ribs is not established as yet.The technology (referring to Japanese kokai publication hei 7-323302 communique) of applying for before the applicant etc. for example is by using 4 rolled steel machines as final finishing mill, though can make the deformed bar of 4 ribs, the cost height.In addition, utilize 2 rolled steel machines to carry out method that final finish rolling forms 4 ribs practicability not as yet.
The present invention is conceived to the above-mentioned fact and finishes, and purpose is to utilize 2 rolled steel machines to carry out final finish rolling, to obtain to form the deformed bar of joint and 4 ribs.
Brief summary of the invention
The milling method of deformed bar of the present invention, utilize the final finishing mill of the continuous hot-rolling equipment that many 2 rolled steel machine arranged in series get up, on the periphery of the blank of being sent to, form joint and rib, it is characterized in that: two a pair of rolls have be roughly semicircular all grooves on the roll circumference face along the section of whole circumference direction setting, on this groove face in week with this groove joint groove arranged in a crossed manner, be roughly trapezoidal and peristome width kerve along the section of whole circumference direction setting greater than bottom width at the groove width direction central part of above-mentioned all grooves in week; Utilize above-mentioned two a pair of rolls to carry out final finish rolling, form 4 ribs by joint flash and the kerve that comes out from roll shop building.
Adopt this method, form 2 ribs, in addition, form 2 ribs by the kerve that is formed on each roll by the joint flash that comes out from roll shop building.Therefore the rib that is formed by kerve is the groove width direction central part that is arranged at above-mentioned all grooves, can obtain at circumferencial direction uniformly-spaced or roughly equally spaced form the deformed bar of 4 ribs.
In addition, above-mentioned roll is preferably for example shown in Figure 1, the bottom surface of kerve 1 is consistent with the bottom surface of joint groove 2, and joint groove 2 vertically disposes with all grooves 3, and as shown in Figure 2, make the width H1 between the formed rib 4a of joint flash, 4b consistent or as one man be rolled substantially with the section diameter of a circle A1 of joint groove 2.
Adopt this method, 4 ribs uniformly-spaced or roughly equally spaced form at circumferencial direction, and in addition, the whole outer peripheral face of ribs or unanimities substantially consistent with the excircle of joint becomes vertical with rib with the time.
In addition, above-mentioned roll preferably as shown in Figure 2, the degree of depth of kerve 1 is below 10% of goods average diameter, the section of kerve 1 is roughly isosceles trapezoid, its uneven two limit angulations are more than 10 °, and the bottom width b of kerve 1 is more than 4% of above-mentioned average diameter.
Moreover, to above-mentioned what is called roughly trapezoidal with isosceles trapezoid roughly, the two parallel limits of trapezoidal (not comprising parallelogram) and isosceles trapezoid, non-rectilinear also strictly speaking, but be concentrically ringed circular-arc.And, the bottom surface of a square one-tenth kerve of the weak point of these circular arcs, a long square one-tenth peristome.In addition, the average diameter of above-mentioned so-called goods is meant the average diameter of the pole part of the joint of removing deformed bar and rib.
At this, as shown in Figure 2, though the speed of gyration on the periphery that carries out speed and roll R1, R2 of blank S is consistent, be the bight a of all grooves 3 of the peristome of kerve 1, its radius of gyration is little, the speed of gyration at a place, this bight than blank S to carry out speed slow.Therefore, this bight a is subjected to the effect of excessive power when rolling, breaks easily, but limits the shape of kerve 1 as described above, can be difficult for breaking.
Whether, in the degree of depth that make kerve 1 be 10% the situation of goods average diameter of the upper limit of JIS specification under, promptly get the result shown in the diagram of Fig. 3 if in fact, changing above-mentioned angle θ and groove width b, studying at the bight of roll a and break.By this diagram as can be known, be under 10% the situation of goods average diameter in the degree of depth of kerve 1, if angle θ is more than 10 °, and groove width b is 4% when above of goods average diameter, then the roll rhegma can not take place.Therefore in addition, the depth as shallow of kerve 1 is difficult to break on roll, and under 10% situation of the not enough goods average diameter of the degree of depth of kerve 1, if angle θ is more than 10 °, groove width b is 4% when above of goods average diameter, also the roll rhegma can not take place.
Moreover the groove width b of kerve 1 is wide, and angle θ is big, and roll more is difficult to break, and their higher limit is set according to the standard of articles that JIS etc. is formulated.
The present invention also provides deformed bar the rolling roll of using, this deformed bar rolling with roll have be roughly semicircular all grooves on the roll circumference face along the section of whole circumference direction setting, on this groove face in week with this groove joint groove arranged in a crossed manner, be roughly trapezoidal and peristome width kerve along the section of whole circumference direction setting greater than bottom width at the groove width direction central part of above-mentioned all grooves in week.
Above-mentioned deformed bar is rolling, and preferably the bottom surface of above-mentioned kerve is consistent with the bottom surface of joint groove with roll, and joint groove and above-mentioned all grooves vertically dispose.
Rolling more meeting with roll of above-mentioned deformed bar it is desirable to, the degree of depth of above-mentioned kerve is below 10% of goods average diameter, the section of above-mentioned kerve is roughly isosceles trapezoid, its uneven two limit angulations are more than 10 °, and the bottom width of this kerve is more than 4% of above-mentioned average diameter.
The accompanying drawing simple declaration
Fig. 1 represents the roll of the final processing of the best of the present invention with 2 rolled steel machines, is the expanded view of roll circumference face (a), (b) is the D-D cutaway view of (a).
Fig. 2 is that the front view of the final processing of the best approach of the present invention with the roll configuration of 2 rolled steel machines implemented in expression.
Fig. 3 is the diagram that is used to illustrate effect of the present invention.
Fig. 4 is the front view of the final processing of expression in the example of the present invention with the roll pass of 2 rolled steel machines.
Fig. 5 represents (a)～(c) to represent different states respectively by the state of resulting deformed bar in feed roller in the example of the present invention.
Fig. 6 represents an example of deformed bar before, (a) is side view, (b) is its X-X cutaway view.
Fig. 7 is the sketch map of the final processing of the expression deformed bar that is used to obtain Fig. 6 with the roll configuration of 2 rolled steel machines.
Fig. 8 is the expanded view (a) and the Y-Y cutaway view (b) thereof of the roll of presentation graphs 7.
Fig. 9 represents that before the employed final processing of deformed bar rolling mill with the roll of 2 rolled steel machines, is the expanded view of roll circumference face (a), (b) is the Z-Z cutaway view of (a).
The specific embodiment of the present invention
In order to illustrate in greater detail the present invention, according to a description of drawings one embodiment.
Fig. 1 represents the roll of employed in this embodiment final processing with 2 rolled steel machines, is the expanded view of roll circumference face (a), (b) is the D-D cutaway view of (a).In addition, Fig. 4 represents in this embodiment, by the front view of the formed final processing of the roll of Fig. 1 with the roll pass of 2 rolled steel machines.
As shown in Figure 1, roll R1 (R2) forms section along the whole circumference direction and is semicircular all grooves 3 roughly on its periphery.In addition, on this groove 3, with the groove width direction centre line L of all grooves 3 in week 0Vertically be processed with the joint groove 2 of Rack.This joint groove 2 (is a groove width direction centre line L along the circumferencial direction of all grooves 3 0) by uniformly-spaced forming.In addition, forming section at the groove width direction central part of all grooves 3 along the whole circumference direction is the kerve 1 of roughly isosceles trapezoid, and its peristome width is greater than bottom width.
As shown in Figure 4, the bottom surface of kerve 1 is consistent with the bottom surface of joint groove 2.In addition, kerve 1 is 0.85mm with the degree of depth C of joint groove 2, the diameter of pass (average diameters of goods) A 2Be 15.9mm, the uneven two limit angulation θ of the isosceles trapezoid of the section of formation kerve 1 are 60 °, and the bottom width b of kerve 1 is 2.0mm.
In addition, divide formation rake 3a in the interface of roll R1, R2 periphery and all grooves 3.Roll seam d is 2.0mm, and angulation β is 60 ° between the rake 3a of two roll R1, R2.At this, the degree of depth C of kerve 1 is equivalent to 5.3% of goods average diameter A2, and the groove width b of kerve 1 bottom side is equivalent to 13% of goods average diameter A2.
2 such rolled steel machines are provided with as final finishing mill, the pole material that lists the outside dimension that is rolled down to regulation at 2 common rolled steel machines is carried out finish rolling.At this moment, consistent with the section diameter of a circle A1 of joint groove 2 as above-mentioned shown in Figure 2 for the width H1 that makes the blank S that comes out by final finishing mill by the formed rib 4a of joint flash, 4b, the roll seam that is configured in final finishing mill rolling mill is nearby adjusted.
Its result does not have roll rhegma accident, the deformed bar that is obtained, and its 4 ribs roughly equally spaced form at circumferencial direction, and all the periphery of rib is consistent with the periphery of joint, and joint is vertically formed with respect to rib.
Therefore, the deformed bar 5 that is obtained even turn round in the feed roller 6 as the feeder of processing equipment, at least also has a rib 4 to contact with each groove face 6a of feed roller 6 always shown in Fig. 5 (a)～(c).Thereby deformed bar 5 is supported reliably and is correctly sent to by feed roller 6.
In addition, because joint 12 is vertical with rib 4, do not produce the advantage of distortion when also having bending machining.
In addition, in the above-described embodiments, because the degree of depth C of kerve 1 is goods average diameter A 25.3%, kerve 1 bottom groove width b is goods average diameter A 213%, roll rhegma accident can not take place, can stably obtain to have the deformed bar 5 of 4 ribs 4.Industrial applicibility
As mentioned above, in the method for the invention, utilize 2 rolled steel machines to carry out final finish rolling, can stably obtain to form the deformed bar of joint and 4 ribs.Utilize this method, use the used steel rolling equipment of deformed bar of 2 ribs of manufacturing before, just change the roll of its final fine finishining, can obtain the deformed bar of 4 ribs with 2 rolled steel machines.Therefore, method of the present invention and roll can perform well in making the method for deformed bar of 4 ribs and used roll thereof with low cost.

Claims (6)

1. the milling method of a deformed bar, utilize the final finishing mill of the continuous hot-rolling equipment that many 2 rolled steel machine arranged in series get up, on the periphery of the blank of being sent to, form joint and rib, it is characterized in that: two a pair of rolls have be roughly semicircular all grooves on the roll circumference face along the section of whole circumference direction setting, on this groove face in week with this groove joint groove arranged in a crossed manner, be roughly trapezoidal and peristome width kerve along the section of whole circumference direction setting greater than bottom width at the groove width direction central part of above-mentioned all grooves in week; Utilize above-mentioned two a pair of rolls to carry out final finish rolling, the joint flash and the kerve that come out by roll shop building form 4 ribs.
2. press the milling method of the described deformed bar of claim 1, it is characterized in that: above-mentioned roll, the bottom surface of its kerve (1) is consistent with the bottom surface of joint groove (2), and joint groove and all grooves (3) vertically dispose, and make width (H1) between the formed rib of above-mentioned joint flash (4a, 4b) consistent with the section diameter of a circle (A1) that saves groove or as one man be rolled substantially.
3. press the milling method of the described deformed bar of claim 2, it is characterized in that: above-mentioned roll, the degree of depth of its above-mentioned kerve is below 10% of goods average diameter, the section of above-mentioned kerve is roughly isosceles trapezoid, its uneven two limit angulations (θ) are more than 10 °, and the bottom width of this kerve (b) is more than 4% of above-mentioned average diameter.
4. the rolling roll of using of deformed bar, have be roughly semicircular all grooves on the roll circumference face along the section of whole circumference direction setting, on this groove face in week with this groove joint groove arranged in a crossed manner, be roughly trapezoidal and peristome width kerve along the section of whole circumference direction setting greater than bottom width at the groove width direction central part of above-mentioned all grooves in week.
5. by the rolling roll of use of the described deformed bar of claim 4, it is characterized in that: the bottom surface of above-mentioned kerve is consistent with the bottom surface of saving groove, and saves groove and above-mentioned all grooves vertically dispose.
6. by the rolling roll of using of the described deformed bar of claim 5, it is characterized in that: the degree of depth of above-mentioned kerve is below 10% of goods average diameter, the section of above-mentioned kerve is roughly isosceles trapezoid, its uneven two limit angulations are more than 10 °, and the bottom width of this kerve is more than 4% of above-mentioned average diameter.
CN96197278A 1995-09-28 1996-09-26 Method of rolling deformed bar and roll for deformed bar Pending CN1198111A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP251356/95 1995-09-28
JP7251356A JP2957450B2 (en) 1995-09-28 1995-09-28 Rolling method for deformed steel bars

Publications (1)

Publication Number Publication Date
CN1198111A true CN1198111A (en) 1998-11-04

Family

ID=17221617

Family Applications (1)

Application Number Title Priority Date Filing Date
CN96197278A Pending CN1198111A (en) 1995-09-28 1996-09-26 Method of rolling deformed bar and roll for deformed bar

Country Status (8)

Country Link
EP (1) EP0853988A4 (en)
JP (1) JP2957450B2 (en)
KR (1) KR19990063724A (en)
CN (1) CN1198111A (en)
AU (1) AU710014B2 (en)
BR (1) BR9610698A (en)
TW (1) TW305778B (en)
WO (1) WO1997011796A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007009372A1 (en) * 2005-07-18 2007-01-25 Shusen Luo A method for making handtool head and a rolling mill thereof
CN100363120C (en) * 2004-11-22 2008-01-23 董重光 Reinforced car rubbing roller

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100838624B1 (en) * 2007-01-26 2008-06-16 신수정 Hot rolling method
JP2012223802A (en) * 2011-04-21 2012-11-15 Otani Steel Corporation Inc Deformed steel bar and rolling method for the same
KR200470061Y1 (en) * 2012-04-05 2013-11-25 동국제강주식회사 Oval shape guide roller and rolling mill having the same
EP3043895B1 (en) * 2013-09-10 2021-04-07 Augma Biomaterials Ltd. Dual component applicator
JP6281515B2 (en) * 2015-03-26 2018-02-21 Ｊｆｅスチール株式会社 Rolling method for deformed bar
CN105436233A (en) * 2015-12-16 2016-03-30 重庆麦拓科技有限公司 Processing technology of cold-rolled steel bar
CN106269853A (en) * 2016-08-16 2017-01-04 重庆市晟庄建材有限责任公司 A kind of high ductility cold-rolled ribbed bars processing method
CN109396180B (en) * 2018-10-29 2020-09-25 甘肃酒钢集团宏兴钢铁股份有限公司 Production method of SD420W bamboo joint reinforcing steel bar
JP7309581B2 (en) * 2019-11-20 2023-07-18 Ｊｆｅ条鋼株式会社 METHOD AND APPARATUS FOR MANUFACTURING DEFORMED BAR WITH REDUCED VARIATION OF OVAL

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH043700Y2 (en) * 1986-03-04 1992-02-05

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100363120C (en) * 2004-11-22 2008-01-23 董重光 Reinforced car rubbing roller
WO2007009372A1 (en) * 2005-07-18 2007-01-25 Shusen Luo A method for making handtool head and a rolling mill thereof

Also Published As

Publication number Publication date
AU710014B2 (en) 1999-09-09
JP2957450B2 (en) 1999-10-04
AU7095896A (en) 1997-04-17
WO1997011796A1 (en) 1997-04-03
KR19990063724A (en) 1999-07-26
TW305778B (en) 1997-05-21
BR9610698A (en) 1999-07-06
EP0853988A1 (en) 1998-07-22
JPH0994602A (en) 1997-04-08
EP0853988A4 (en) 2001-06-06

Similar Documents

Publication Publication Date Title
CN1198111A (en) Method of rolling deformed bar and roll for deformed bar
US5412968A (en) Method for leveling sheet metal
US5649440A (en) Method for calibration of assel rollers
EP1135223A1 (en) Stretch roll forming method and apparatus
CN1010184B (en) Method of indroducing stuff into finishing roll and guide supports therefor
JPS60130401A (en) Device for dividing rolling-material into multiple bars
JPS5884614A (en) Roller leveller
JPS63101009A (en) Multi-roll rolling stand
US20100000073A1 (en) Method of producing at least two plane functional surfaces extending parallel to each other on a pipe
SU995919A1 (en) Method of rolling wedge-shaped sections
SU995921A1 (en) Method of rolling wedge-shaped sections
SU1570806A1 (en) Method of rolling
SU1382558A1 (en) Method of expanding rings
JP3309807B2 (en) Method and apparatus for manufacturing metal material having a circular outer peripheral section
CN1077666A (en) Milling train
EP0623403B1 (en) Method of forming welded pipe and forming stand therefor
EP1181990A3 (en) Reversible guideless rolling mill
SU1502142A1 (en) Multiroll pass
SU995920A1 (en) Method of rolling wedge-shaped sections
RU2152831C2 (en) Method for rolling flanged sections in roughing passes
JPH0156841B2 (en)
SU1759486A1 (en) Drawing roll pass system
JPH044902A (en) Hot rolling method of h-shape steel
RU2011455C1 (en) Method of forming cones of sheet materials
RU2122906C1 (en) Blank rolling method

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C02 Deemed withdrawal of patent application after publication (patent law 2001)
WD01 Invention patent application deemed withdrawn after publication