IL35206A - Apparatus for magnetodynamic testing for flaws in steel ropes with additional means for reducing signal noise - Google Patents
Apparatus for magnetodynamic testing for flaws in steel ropes with additional means for reducing signal noiseInfo
- Publication number
- IL35206A IL35206A IL35206A IL3520670A IL35206A IL 35206 A IL35206 A IL 35206A IL 35206 A IL35206 A IL 35206A IL 3520670 A IL3520670 A IL 3520670A IL 35206 A IL35206 A IL 35206A
- Authority
- IL
- Israel
- Prior art keywords
- rope
- magnetodynamic
- flaws
- testing
- additional means
- Prior art date
Links
Classifications
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B7/00—Details of, or auxiliary devices incorporated in, rope- or cable-making machines; Auxiliary apparatus associated with such machines
- D07B7/02—Machine details; Auxiliary devices
- D07B7/08—Alarms or stop motions responsive to exhaustion or breakage of filamentary material fed from supply reels or bobbins
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
- G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/58—Testing of lines, cables or conductors
- G01R31/59—Testing of lines, cables or conductors while the cable continuously passes the testing apparatus, e.g. during manufacture
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Description
ηιηικπ wy nnnenV o«Bon O'PXQK oy
- Apparatus for magnetodynamic testing for flaws in steel ropes with additional means for reducing signal noise
ANGLO AMERICAN CORPORATION OP SOUTH AFRICA
G. 33490
It is an object of the present invention' to provide improved
apparatus for detecting broken wires in winding ropes.
Apparatus according to the invention includes a circular magnet th ough which the rope is passed, at least two. sensing coils
surrounding the rope and- adapted to 'detect the presence in the
rope of any magnetic dipoles due to broken wires, means to
muLtiply the output of one sensing coil by -the output of the
ot:ier 'sensing coil, and means to display, the , multiplied outputs.
Further according to the invention the multiplying means is of the ty;:>e which produces no output when only one input exists by itself ye; does not double the frequency when identical pulses are applied to its two inputs.
Fu†>ther according to the invention .'the outputs of the two' sensing coils are applied to the multiplying means through amplifiers the. gain"";
of each of which is inversely proportional to the rop,e speed .
so that the outputs' of the amplifiers to the multiplying 'means ':.'■'■<..'. arfe independent of rope speed. ' — . ' . .· · ,. ;'·
To illustrate the invention an embodiment thereof is described' . , '.·, hereunder with reference to the accompanying drawings in which: -
Figure 1 -is. a partly, diagrammatical'- sectional' elevation of- the ';·':";'."'.·;■' apparatus; .·. · ■ ;-" .. s ' ■" ■ _.· .V:-.'.-; ;.
Figure 2 is a sectional plan of the . test-head assembly; and ··
Figure 3 is .'a'.block . schematic -diagram ' of-, the', apparatus . »''·":;·?.< ' ■' .,·.' '
The principle of the present invention is illustrated in
Figures 1 and 2. In these drawings a split tubular permanent magnet 10 is adapted to surround the rope 11 to be tested. ■■
Sensing coils 12 are located between each magnet half and the rope.. The magnets nd the sensing coils are. preferably' mount m a compact test-head assembly.
As was explained at the beginning of this specification, ..... . ' ;...·.·-'. the axial magnetic field in the rope due to the circular ;;.,'· magnets causes small magnetic dipoles to be created between ··'. ';' the1 ends f broken wires in the rope. As the rope moves past' the sensing coils, tfhese small dipoles .cause small voltages to. ,". ·■';." be induced into the. sensing coils and these voltages are .
applied to a multiplier 13 the output .of which '.is. applied to .
a pen galvanometer..' ■ ' ...·
The; step of multiplying the outputs of the sensing coils is' the ' : heart of the present invention. If- one bears in mind that '\' ;'·.''' noise is a random signal and that the voltages induced into
the sensing, coils as :a result of broken wires are 'always in' .' , ph£:se, it will be appreciated , that , by multiplying the
voltages. in the sensing coils, the noise pulses. ill be
effectively eliminated in the strips of the pen galvanometer whereas the pulses due to. the/broken wires .will be emphasised. The.' . . strips will thus be 'much easier ' to read .than conventional strips of this type. ■'..·.· ..;··.." ■ !'
The; .invention, is illustrated in more detail in Figure 3· Ά ' .- ■-■'.'·. ;:.';,;. rubber tyre 20 is adapted to be driven by the rope ΐο· be ;
tested.. The tyre.20 is in turn coupled by means of a set of; .,;.·'"■ ges.rs to a- miniature, alternator 21 whose output Is a frequency...
proportional to the ■ speed of ' the rope. - .The amplitude . of the -alternator, output '.is ' also dependent, on the rope speed but this ,"·'.',.;'··.· is- irrelevan ' for: .the purposes .of- the; invention.
The output of the alternator ■ 21 is applied to a frequency '
to voltage converter 22. The 'output .of the alternator 21 <'
is ";hus a voltage proportional to rope speed.
The outputs of the sensing coils .23 and 24 are applied, to .
amp ifiers 25 and 26. Each of these amplifiers has a gain ·
which is inversely proportional to the output from the
converter 22 which, in turn ^is proportional to rope speed. The :. out ut of each of. the amplifiers 25 and 26 is thus independent ;, of rope speed. · '..'·. "
The outputs of the amplifiers are applied. to, a . four quadrant . .
analogue multiplier 27 in which the' outputs of the two amplifiers 25 and 26 are multiplied.
The Joutput of the multiplier 27 is fed to a matching amplifier '.·' 28 before being fed to the pen galvanometer.
It can be shown mathematically that the multiplication of . :
the two outputs from the amplifiers ' 25 and 26 will result in.
a large output from the multiplier 27 with no doubling 0 f frequency, inso;far as the in-phase voltages of the broken wires are concerned, and a small output of a higher frequency, insofar as the random · .' noise signals are concerned. The galvanometer response is ■ ■'.'.·· limilted and the higher frequency noise. components are' therefore effectively filtered out by the galvanometer so that substantially' ■; only the in-phase signals are displayed on the galvanometer.' strip .·'
In a test on a particular rope with conventional equipment, the --noise to signal ratio for broken wires in the centre of the
rope, was of the order of 6:1. This made it .virtually
impossible to detect the broken wires.- When the same rope' was tested with. the equipment of the' present invention' the signal. o. noisp ratio improved to' 7:1. ' In other w'prds the': signal to . ,.· noise ratio was' improved' by a factor; of ' 42 ,
Claims (1)
- insufficientOCRQuality
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA696269A ZA696269B (en) | 1969-09-03 | 1969-09-03 | D.c.rope testing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| IL35206A0 IL35206A0 (en) | 1970-11-30 |
| IL35206A true IL35206A (en) | 1973-01-30 |
Family
ID=25561443
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IL35206A IL35206A (en) | 1969-09-03 | 1970-09-01 | Apparatus for magnetodynamic testing for flaws in steel ropes with additional means for reducing signal noise |
Country Status (15)
| Country | Link |
|---|---|
| AT (1) | AT336314B (en) |
| BE (1) | BE755698A (en) |
| CH (1) | CH516159A (en) |
| DK (1) | DK127346B (en) |
| ES (1) | ES383377A1 (en) |
| FI (1) | FI53366C (en) |
| FR (1) | FR2060867A5 (en) |
| GB (1) | GB1270748A (en) |
| IL (1) | IL35206A (en) |
| NL (1) | NL163023C (en) |
| NO (1) | NO123589B (en) |
| OA (1) | OA03476A (en) |
| SE (1) | SE362709B (en) |
| ZA (1) | ZA696269B (en) |
| ZM (1) | ZM10570A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| PL148290B1 (en) * | 1985-03-05 | 1989-10-31 | Wyzsza Szkola Pedagog | Magnetic defectograph sensing element for determining changes in cross-sectional areas over substantial length of an object being examined |
| GB8714877D0 (en) * | 1987-06-25 | 1987-07-29 | Coal Industry Patents Ltd | Non-destructive testing device |
| US5036277A (en) * | 1987-11-23 | 1991-07-30 | Crucible Societe Anonyme | Method of and apparatus for detecting cross sectional area variations in an elongate object by the non-inductive measurement of radial flux variations |
| US4929897A (en) * | 1987-11-23 | 1990-05-29 | Crucible Societe Anonyme | Method and apparatus for detecting cross sectional area variations in a elongate object by measuring radial magnetic flux variations using spaced-apart coils |
| CA2054797A1 (en) * | 1990-11-07 | 1992-05-08 | Nicolaas T. Van Der Walt | Electro-magnetic testing of wire ropes |
| EP0816797B1 (en) * | 1996-06-28 | 2002-09-18 | Tokyo Rope Mfg. Co., Ltd. | Apparatus for and method of measuring corrosion degree of cable |
| JP4310112B2 (en) * | 2003-01-15 | 2009-08-05 | 株式会社日立製作所 | Rope and rope deterioration diagnosis method |
| ES2277751B1 (en) * | 2005-07-19 | 2008-06-16 | Fundacion Barredo | EQUIPMENT FOR PERMANENT AND CONTINUOUS CONTROL OF STEEL CABLES IN TRANSPORTATION OR ELEVATION FACILITIES OF PERSONAL AND MATERIALS. |
-
0
- BE BE755698D patent/BE755698A/en not_active IP Right Cessation
-
1969
- 1969-09-03 ZA ZA696269A patent/ZA696269B/en unknown
-
1970
- 1970-09-01 NO NO3329/70A patent/NO123589B/no unknown
- 1970-09-01 IL IL35206A patent/IL35206A/en unknown
- 1970-09-02 DK DK451670AA patent/DK127346B/en not_active IP Right Cessation
- 1970-09-02 ZM ZM105/70A patent/ZM10570A1/en unknown
- 1970-09-02 OA OA54019A patent/OA03476A/en unknown
- 1970-09-02 NL NL7013006.A patent/NL163023C/en not_active IP Right Cessation
- 1970-09-02 SE SE11953/70A patent/SE362709B/xx unknown
- 1970-09-02 FR FR7031975A patent/FR2060867A5/fr not_active Expired
- 1970-09-03 CH CH1315770A patent/CH516159A/en not_active IP Right Cessation
- 1970-09-03 AT AT800070A patent/AT336314B/en not_active IP Right Cessation
- 1970-09-03 FI FI2430/70A patent/FI53366C/en active
- 1970-09-03 GB GB42278/70A patent/GB1270748A/en not_active Expired
- 1970-09-03 ES ES383377A patent/ES383377A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ZM10570A1 (en) | 1971-05-21 |
| FI53366C (en) | 1978-04-10 |
| NO123589B (en) | 1971-12-13 |
| DK127346B (en) | 1973-10-22 |
| OA03476A (en) | 1971-03-30 |
| CH516159A (en) | 1971-11-30 |
| BE755698A (en) | 1971-02-15 |
| FR2060867A5 (en) | 1971-06-18 |
| GB1270748A (en) | 1972-04-12 |
| SE362709B (en) | 1973-12-17 |
| DE2043521A1 (en) | 1971-03-11 |
| DE2043521B2 (en) | 1977-02-10 |
| ATA800070A (en) | 1976-08-15 |
| IL35206A0 (en) | 1970-11-30 |
| NL163023C (en) | 1980-07-15 |
| FI53366B (en) | 1977-12-30 |
| NL7013006A (en) | 1971-03-05 |
| NL163023B (en) | 1980-02-15 |
| ES383377A1 (en) | 1973-01-16 |
| ZA696269B (en) | 1971-02-24 |
| AT336314B (en) | 1977-04-25 |
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