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CA2787694A1 - Methods of manufacturing a resilient rail clip - Google Patents

Methods of manufacturing a resilient rail clip Download PDF

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Publication number
CA2787694A1
CA2787694A1 CA2787694A CA2787694A CA2787694A1 CA 2787694 A1 CA2787694 A1 CA 2787694A1 CA 2787694 A CA2787694 A CA 2787694A CA 2787694 A CA2787694 A CA 2787694A CA 2787694 A1 CA2787694 A1 CA 2787694A1
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CA
Canada
Prior art keywords
bent rod
amount
load
deflection
predetermined
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.)
Granted
Application number
CA2787694A
Other languages
French (fr)
Other versions
CA2787694C (en
Inventor
Stephen John Cox
David Rhodes
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.)
Pandrol Ltd
Original Assignee
Pandrol 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
Application filed by Pandrol Ltd filed Critical Pandrol Ltd
Publication of CA2787694A1 publication Critical patent/CA2787694A1/en
Application granted granted Critical
Publication of CA2787694C publication Critical patent/CA2787694C/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21DWORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00Making other particular articles
    • B21D53/36Making other particular articles clips, clamps, or like fastening or attaching devices, e.g. for electric installation
    • EFIXED CONSTRUCTIONS
    • E01CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01BPERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
    • E01B9/00Fastening rails on sleepers, or the like
    • E01B9/02Fastening rails, tie-plates, or chairs directly on sleepers or foundations; Means therefor
    • E01B9/28Fastening on wooden or concrete sleepers or on masonry with clamp members
    • E01B9/30Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips
    • EFIXED CONSTRUCTIONS
    • E01CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01BPERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
    • E01B9/00Fastening rails on sleepers, or the like
    • E01B9/02Fastening rails, tie-plates, or chairs directly on sleepers or foundations; Means therefor
    • E01B9/28Fastening on wooden or concrete sleepers or on masonry with clamp members
    • E01B9/30Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips
    • E01B9/303Fastening on wooden or concrete sleepers or on masonry with clamp members by resilient steel clips the clip being a shaped bar

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Clamps And Clips (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
  • Railway Tracks (AREA)
  • Straightening Metal Sheet-Like Bodies (AREA)
  • Bending Of Plates, Rods, And Pipes (AREA)

Abstract

A method of manufacturing a resilient rail clip comprises bending a rod, made of metal having a hardness value falling within a known hardness value range, into a predetermined shape and then subjecting the bent rod to a cold setting process in order to induce in the bent rod a predetermined amount of permanent set (S). One cold setting process comprises applying a first load (F0) to part of the bent rod so as to cause a first amount of deflection of that part of the bent rod, which first load (F0) is a predetermined load having a value equal to or greater than that required to reach the yield point of metal having the highest hardness value in the said hardness value range, measuring the first amount of deflection (dx) of the said part of the bent rod achieved by applying the predetermined first load (F0), determining, on the basis of the measured deflection amount (dx), either (i) a second load (F0 + ?FX), which, when applied to the said part of the bent rod, will cause the bent rod to acquire the predetermined amount of permanent set (S), or (ii) a second amount of deflection (dx + ?dx) of the said part of the bent rod required in order to bring about in the bent rod the predetermined amount of permanent set (S), and applying the second load (F0 + ?FX ) to the said part of the bent rod or deflecting the said part of the bent rod by the determined second amount of deflection (dx + ?dx). An alternative cold setting process comprises deflecting part of the bent rod by a predetermined first amount (d0) by applying a first load (Fx) having a value equal to or greater than that required to reach the yield point of metal having the highest hardness value in the said hardness value range, measuring the amount of the first load (Fx) required to achieve the predetermined first amount of deflection (d0), determining, on the basis of the measured load, either (i) a second deflection amount (d0 + ?dx) required in order to bring about in the bent rod the predetermined amount of permanent set (S), or (ii) a second load (Fx + ?FX), which, when applied to the said part of the bent rod, will cause the bent rod to acquire the predetermined amount of permanent set (S), and deflecting the said part of the bent rod by the determined second deflection amount (d0 + ?dx) or applying the determined second load (Fx + ?FX) to the said part of the bent rod.

Description

METHODS OF MANUFACTURING A RESILIENT RAIL CLIP

The present invention relates to a method of manufacturing a resilient rail clip.

Various forms of resilient rail clips are known, for example as shown and described in GB1510224A and EP0619852B. A known method of manufacturing a resilient rail clip comprises bending a metal rod (usually made of steel) into a predetermined shape and then subjecting the bent rod to a cold setting process to achieve the final form of the clip.
Such rods have a common load-deflection characteristic with a common slope (clip stiffness) up to the elastic limit of the metal from which the bent rod is formed. Cold setting is intended to take the bent rod beyond that elastic limit, thereby inducing a permanent deflection (set) into the resulting clip, such that if it is then unloaded and taken up the load-deflection characteristic a second time, the load-deflection characteristic will be linear up to a much higher load, that is up to the load at which the new characteristic intercepts that for the original rod. One of the key problems in cold-setting is that the metal rods from which the clips are made themselves vary in hardness, typically between 44 and 48 Rockwell hardness. Since the elastic limit of rods made from softer metal is lower than that of rods made from harder metal, if all rods are taken to a fixed deflection, they will all unload down slightly different parallel lines and take on different and varying amounts of set. The softer rods will take on more set, the harder ones less set. This is illustrated in Figure 1A of the accompanying drawings, which shows the load-deflection characteristics of a soft clip and a hard clip and the difference in set As between them after cold setting. This difference in set results in clips that have different geometries (above and beyond the variation already inherent in manufacture), where the geometry depends on the hardness. Thus, although these cold-set clips will all have the same stiffness, regardless of hardness, driving these clips into a fixed assembly which deflects them all by the same amount will result in the clips generating slightly different loads at the portion (the "toe") of the clip which bears on the railway rail. It is impractical to measure the hardness of each clip to be cold set directly before the start of the cold-setting process.
Moreover, as shown in Figures 1 B and 1 C of the accompanying drawings, the problem cannot be overcome simply by changing the fixed amount of deflection applied during cold-setting (Fig. 1 B), or by applying a fixed force instead of a fixed deflection (Fig. 1 C), as this
2 does not address the underlying problem. In the past, in an attempt to address this problem, the rod is repeatedly cold-set a number of times, but this is not fully effective.
According to an embodiment of a first aspect of the present invention there is provided a method of manufacturing a resilient rail clip comprising bending a rod, made of metal having a hardness value falling within a known hardness value range, into a predetermined shape and then subjecting the bent rod to a cold setting process in order to induce in the bent rod a predetermined amount of permanent set, wherein the cold setting process comprises: applying a first load to part of the bent rod so as to cause a first amount of deflection of that part of the bent rod, which first load is a predetermined load having a value equal to or greater than that required to reach the yield point of metal having the highest hardness value in the said hardness value range; measuring the first amount of deflection of the said part of the bent rod achieved by applying the predetermined first load; determining, on the basis of the measured deflection amount, either (i) a second load, which, when applied to the said part of the bent rod, will cause the bent rod to acquire the predetermined amount of permanent set, or (ii) a second amount of deflection of the said part of the bent rod required in order to bring about in the bent rod the predetermined amount of permanent set; and applying the determined second load to the said part of the bent rod or deflecting the said part of the bent rod by the determined second amount of deflection.

According to an embodiment of a second aspect of the present invention there is provided a method of manufacturing a resilient rail clip comprising bending a rod, made of metal having a hardness value failing within a known hardness value range, into a predetermined shape and then subjecting the bent rod to a cold setting process in order to induce in the bent rod a predetermined amount of permanent set, wherein the cold setting process comprises: deflecting part of the bent rod by a predetermined first amount by applying a first load having a value equal to or greater than that required to reach the yield point of metal having the highest hardness value in the said hardness value range; measuring the amount of the first load required to achieve the predetermined first amount of deflection; determining, on the basis of the measured first load, either (i) a second deflection amount required in order to bring about in the bent rod the predetermined amount of permanent set, or (ii) a second load, which, when applied to the said part of the bent rod, will cause the bent rod to acquire the predetermined amount of permanent set; and deflecting the said part of the bent rod by
3 PCT/EP2010/068893 the determined second deflection amount or applying the determined second load to the said part of the bent rod.

Reference will now be made, by way of example, to the accompanying drawings, in which:

Figures 1A to 1C (described above) show the load-deflection characteristics of two rail clips of different respective hardness which have been cold set according to a previously-proposed method;
Figures 2A and 2B show respective flow diagrams depicting two alternative cold setting processes used in embodiments of the present invention;

Figure 3A shows a rail clip undergoing part of a cold setting process used in an embodiment of the present invention and Figure 3B shows the same rail clip after cold setting with a set caused by that cold setting process; and Figures 4A and 4B each show the load-deflection characteristics of two rail clips of different respective hardness, the thicker lines showing the characteristics after the clips have been cold set according to a method embodying the present invention and the thinner lines showing the characteristics of the clips before cold setting, in which Figures 4A and 4B correspond respectively to methods embodying the first aspect and the second aspect of the present invention.

According to an embodiment of the present invention a rod of metal, having a hardness value falling within a known hardness value range, is bent into a predetermined clip shape (see Figure 3A) and then subjected to a two-stage cold setting process, as shown in the flow diagrams of Figure 2A or 2B. Firstly, the rod is loaded to a level equal to or beyond the yield point of a rod having a hardness value at the top of the hardness value range (STEP 1). Then, depending on the method being used, either a measurement is taken of how much deflection dx has resulted in STEP 1 from a fixed applied force F0 (STEP 2, Figure 2A), or how much force Fx has been required in STEP
1 to reach a fixed deflection do (STEP 2, Figure 2B). In the method of Figure 2A, which embodies the first aspect of the present invention, the measured deflection dx is then used to determine the amount of force FO + AFx or second deflection amount dg + Adx (STEP 3, Figure 2A) required in order to induce in the bent rod a predetermined
4 amount of permanent set S in a second stage of the process, during which the larger force or deflection is applied to the rod. Similarly, in the method of Figure 2B, which embodies the second aspect of the present invention, the measured force FX is then used to determine the deflection d0 + Adx or second load FX + AFX (STEP 3, Figure 2B) required in order to induce in the bent rod a predetermined amount of permanent set S in a second stage of the process, during which the larger deflection or force is applied to the rod. In each case the measured values are used by equipment (and/or by a person) to find the additional force/deflection required, for example by reference to a predetermined look-up table or by calculation. In the second processing stage (STEP 4), the rod is subjected to the force or deflection determined in STEP 3 of the preceding stage, the amount of which will vary depending on the hardness of the rod, such that the resulting clip (see Figure 36) is always set to a point that lies along a line that is parallel to the initial load-deflection characteristic of the original rod, as shown in Figures 4A and 4B. In other words, as shown in Figures 4A and 4B, each clip when unloaded will always fall back along an extension of this line, and thus all clips made using this method will have the same amount of set, and therefore the same finished geometry, as each other, regardless of the hardness of the rod. Thus, employing a method embodying the present invention allows the geometry of the clip after the cold-setting process to be closely defined, and in particular it may be more precisely defined than the geometry of the clip before the cold-setting process.

Figure 4A shows the load-deflection characteristics for clips of different respective hardness, before (thinner lines) and after (thicker lines) cold setting by a method embodying the first aspect of the present invention, in which a measurement is taken of how much deflection, dH (hard clip) or ds (soft clip), has resulted from application to the clip of a fixed applied force FO, and the measured deflection for that clip (dH/ds) is then used to determine the amount of force, FO + AFH (hard clip) or F0 + AFs (soft clip), or the amount of deflection, dH + AdH (hard clip) or ds + Ads (soft clip), required in order to achieve a predetermined amount of permanent set S. All clips cold set in this manner, throughout the whole of the hardness range, will have the same set S.
Similarly, Figure 4B shows the load-deflection characteristics for clips of different respective hardness, before (thinner lines) and after (thicker lines) cold setting by a method embodying the second aspect of the present invention, in which a measurement is taken of how much force, FH (hard clip) or Fs (soft clip), is required in order to achieve a fixed deflection do of the clip, and the measured force for that clip (FH/Fs) is then used to determine the amount of deflection, do .+ AdH (hard clip) or dc' + Ads (soft clip), or the amount of force, FH + IFH (hard clip) or FS + IFS (soft clip), required in order to achieve a predetermined amount of permanent set S. All clips cold set in this manner, throughout the whole of the hardness range, will have the same set S.
5 These methods are particularly advantageous when using hydraulic equipment of the type having force and deflection control, as this allows the determination to be made effectively instantaneously so that there is scarcely a pause in the cold-setting process.

Claims (2)

Claims
1. A method of manufacturing a resilient rail clip comprising bending a rod, made of metal having a hardness value falling within a known hardness value range, into a predetermined shape and then subjecting the bent rod to a cold setting process in order to induce in the bent rod a predetermined amount of permanent set, wherein the cold setting process comprises:
applying a first load to part of the bent rod so as to cause a first amount of deflection of that part of the bent rod, which first load is a predetermined load having a value equal to or greater than that required to reach the yield point of metal having the highest hardness value in the said hardness value range;
measuring the first amount of deflection of the said part of the bent rod achieved by applying the predetermined first load;
determining, on the basis of the measured deflection amount, either (i) a second load, which, when applied to the said part of the bent rod, will cause the bent rod to acquire the predetermined amount of permanent set, or (ii) a second amount of deflection of the said part of the bent rod required in order to bring about in the bent rod the predetermined amount of permanent set; and applying the determined second load to the said part of the bent rod or deflecting the said part of the bent rod by the determined second amount of deflection.
2. A method of manufacturing a resilient rail clip comprising bending a rod, made of metal having a hardness value falling within a known hardness value range, into a predetermined shape and then subjecting the bent rod to a cold setting process in order to induce in the bent rod a predetermined amount of permanent set, wherein the cold setting process comprises:
deflecting part of the bent rod by a predetermined first amount by applying a first load having a value equal to or greater than that required to reach the yield point of metal having the highest hardness value in the said hardness value range;
measuring the amount of the first load required to achieve the predetermined first amount of deflection;
determining, on the basis of the measured first load, either (i) a second deflection amount required in order to bring about in the bent rod the predetermined amount of permanent set, or (ii) a second load, which, when applied to the said part of the bent rod, will cause the bent rod to acquire the predetermined amount of permanent set; and deflecting the said part of the bent rod by the determined second deflection amount or applying the determined second load to the said part of the bent rod.
CA2787694A 2010-01-27 2010-12-03 Methods of manufacturing a resilient rail clip Active CA2787694C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB1001301.9 2010-01-27
GB1001301A GB2477282A (en) 2010-01-27 2010-01-27 Method of manufacturing a resilient metal rail clip with hardness within a known range
PCT/EP2010/068893 WO2011091893A1 (en) 2010-01-27 2010-12-03 Methods of manufacturing a resilient rail clip

Publications (2)

Publication Number Publication Date
CA2787694A1 true CA2787694A1 (en) 2011-08-04
CA2787694C CA2787694C (en) 2017-02-07

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CA2787694A Active CA2787694C (en) 2010-01-27 2010-12-03 Methods of manufacturing a resilient rail clip

Country Status (18)

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US (1) US20130074559A1 (en)
EP (1) EP2528702B1 (en)
JP (1) JP5677466B2 (en)
KR (1) KR101779394B1 (en)
CN (1) CN102712028B (en)
AU (1) AU2010344043B2 (en)
BR (1) BR112012017549B1 (en)
CA (1) CA2787694C (en)
DK (1) DK2528702T3 (en)
ES (1) ES2531309T3 (en)
GB (1) GB2477282A (en)
MX (1) MX2012008685A (en)
PL (1) PL2528702T3 (en)
PT (1) PT2528702E (en)
RU (1) RU2543588C2 (en)
SI (1) SI2528702T1 (en)
WO (1) WO2011091893A1 (en)
ZA (1) ZA201205545B (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4332300A1 (en) 2022-08-29 2024-03-06 voestalpine Turnout Technology Zeltweg GmbH Tension spring for holding down a track body element

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NL163277C (en) * 1974-02-26 1984-03-16 Everts & Van Der Weyden Nv METHOD FOR MAKING A RAIL CLAMP.
GB1510224A (en) * 1975-11-07 1978-05-10 Pandrol Ltd Railway rail fastening clip and a railway rail-and-fastening assembly employing it
NL182379C (en) * 1978-07-19 1988-03-01 Everts & Van Der Weyden Nv METHOD OF MANUFACTURING A C-SHAPED RAIL CLAMP.
US4300380A (en) * 1978-10-13 1981-11-17 Pandrol Limited Apparatus and a method for use in making a railway rail-fastening clip
FI793721A (en) * 1978-11-29 1980-05-30 Pandrol Ltd FRAMEWORK FOR THE PURPOSE OF FRAMEWORK FOR FRAMEWORK
NL7906455A (en) * 1979-08-28 1981-03-03 Everts & Van Der Weyden Nv RAIL CLAMP.
EP0027839B1 (en) * 1979-10-26 1983-07-27 RALPH McKAY LIMITED A rail clip holder
OA09065A (en) * 1987-10-19 1991-10-31 Pandrol Ltd Fastening railway rails.
IN185922B (en) 1991-12-18 2001-05-19 Pandrol Ltd
WO1994028245A1 (en) * 1993-06-02 1994-12-08 Jude Odihachukwunma Igwemezie Improved rail tie, tie plate and clip
GB2298442B (en) * 1995-03-03 1999-01-13 Pandrol Ltd Railway rail-fastening clip and assembly
US7383709B2 (en) * 2005-08-04 2008-06-10 Custom Machining Services, Inc. System and process for crimping a fitting to a fluid conduit
JP4842758B2 (en) * 2006-10-06 2011-12-21 太平工業株式会社 Rail fastening method with wire spring clip
WO2008140122A1 (en) * 2007-05-09 2008-11-20 Nippon Steel Corporation Thin plate press molding device and thin plate press molding method
HUP0800082A2 (en) * 2008-02-12 2009-10-28 Robert Csepke Clamping device for fastening railway rails on cross-sleeper and fastener spring thereof
ITRM20080078A1 (en) * 2008-02-12 2009-08-13 Cml Intarnational S P A METHOD OF VERIFICATION AND COMMAND TO CURVE IN AN CONTINUOUS WAY A PIECE EXTENDED ACCORDING TO VARIABLE CURCATORS SPOKES AND MACHINE SO COMMANDED
AU2010201544A1 (en) * 2009-04-21 2010-11-04 Betaswage Pty Ltd Control of metal cold forming machines
IT1394105B1 (en) * 2009-05-06 2012-05-25 Cml Int Spa MACHINE TO TURN CONTINUOUSLY AN EXTENDED PIECE ACCORDING TO PREDETERMINATED RAYS

Also Published As

Publication number Publication date
KR20120116006A (en) 2012-10-19
ZA201205545B (en) 2013-04-24
ES2531309T3 (en) 2015-03-12
CN102712028A (en) 2012-10-03
JP2013518196A (en) 2013-05-20
CA2787694C (en) 2017-02-07
EP2528702A1 (en) 2012-12-05
CN102712028B (en) 2014-11-05
MX2012008685A (en) 2012-08-23
US20130074559A1 (en) 2013-03-28
GB201001301D0 (en) 2010-03-10
PL2528702T3 (en) 2015-07-31
DK2528702T3 (en) 2015-05-26
BR112012017549A2 (en) 2016-06-28
EP2528702B1 (en) 2015-02-18
KR101779394B1 (en) 2017-09-18
RU2543588C2 (en) 2015-03-10
AU2010344043A1 (en) 2012-08-16
JP5677466B2 (en) 2015-02-25
BR112012017549B1 (en) 2020-04-22
SI2528702T1 (en) 2015-05-29
GB2477282A (en) 2011-08-03
AU2010344043B2 (en) 2014-07-17
RU2012136430A (en) 2014-03-10
WO2011091893A1 (en) 2011-08-04
PT2528702E (en) 2015-02-27

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