Method for detection of a flaw or flaws in a railway track, and a rail vehicle to be used in such a method

{
  "publication_number": "US9731734B2",
  "country": "US",
  "kind": "B2",
  "title": "Method for detection of a flaw or flaws in a railway track, and a rail vehicle to be used in such a method",
  "abstract": "Rail vehicle (1) having rail wheels (3,4) accommodated to guide the rail vehicle along a railway track (2) and said vehicle comprising means for detection of a flaw or flaws in the railway track, wherein the rail vehicle is provided with a noncontact vibrometer (9,10) which is arranged to measure vibrational movement of the railway track surface.",
  "claims": [
    "1. A rail vehicle having rail wheels accommodated to guide the rail vehicle along a railway track and said vehicle comprising means for detection of a flaw or flaws in the railway track, which rail vehicle is provided with a noncontact vibrometer which is arranged to measure vibrational movement of a railway track surface, wherein each of the wheels is connected to the vehicle by an intermediate axle box providing a bearing for the wheel, characterized in that said axle box is provided with at least one accelerometer and a comparator on or external to the vehicle compares railway track surface vibrations as measured with the noncontact vibrometer with vibratory signals from the at least one accelerometer.",
    "2. A method for detection of a flaw or flaws in a railway track, the method comprising the steps of: moving a rail vehicle along the railway track to excite the railway track into vibration; measuring vibrational movement of a railway track surface with a noncontact vibrometer; and comparing railway track surface vibrations as measured with the noncontact vibrometer with vibratory signals derived from one or more axle box accelerometers of the vehicle."
  ],
  "description_excerpt": "Not Applicable.\n\nNot Applicable.\n\nNot Applicable.\n\nNot Applicable.\n\nNot Applicable.\n\nField of the Invention (Technical Field)\n\nThe invention relates to a method for detection of a flaw or flaws in the railway track, and to a rail vehicle to be used in such a method.\n\nDescription of Related Art Including Information Disclosed Under 37 C.F.R. §§1.97 and 1.98\n\nA method for detection of rail top defects in a rail-way track by measuring an axle box acceleration signal of the rail vehicle is known from the Dutch patent NL 2 003 351. Such rail top defects are local short vertical geometrical deviations that may cause impact between the rails of the railway-track and the rolling wheels of a rail vehicle. Unless repaired a light rail top defect or squat will grow into a moderate defect, and subsequently into a severe defect. Rail fracture and damages to its fastening, the rail pads, sleepers and ballast (or slab) may ultimately occur if no remedial action is taken.\n\nThe invention is concerned with dealing with a broader range of problems than only squats. Railway tracks have a superstructure and a substructure. The superstructure comprises rails, switches and crossings (S & C), insulated joints (IJ), fasteners, sleepers and ballast (or slab). Due to the interaction between the wheels of the train and the track, dynamic forces arise between the wheels and the rails. As a consequence thereof stresses and strains arise in and between the track components, resulting in wear, deformation, and eventually possibly breakdown of the railway superstructure due to (metal) fatigue.",
  "cpc": [
    "B61L 23/042",
    "B61K 9/10",
    "B61L 23/044",
    "B61L 23/045",
    "B61L 23/047",
    "B61L 23/048"
  ],
  "ipc": [
    "B61L 23/04",
    "B61K 9/10"
  ],
  "assignees": [
    "Technische Universiteit Delft"
  ],
  "inventors": [
    "Zili Li",
    "Daniel Rixen"
  ],
  "filing_date": "2012-08-28",
  "publication_date": "2017-08-15",
  "grant_date": "2017-08-15",
  "priority_date": "2011-08-29",
  "application_number": "US-201214342096-A",
  "family_id": "46832555",
  "cited_by_count": 2,
  "citations": [
    "US6371417B1",
    "WO2000076828A1",
    "US20070163352A1",
    "JP2005331263A",
    "WO2011019273A1",
    "JP2011225188A"
  ]
}