Patents Assigned to Tornbloms Kvalitetskontroll AB
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Patent number: 5117185Abstract: In crack-sensing equipment for hot steel strands, a movable transducer is linked to its sensing electronic circuit via an inductive transmission link to obviate the use of flexible conductors and/or slip couplings.Type: GrantFiled: March 28, 1990Date of Patent: May 26, 1992Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 5111412Abstract: A device for simulating a moving test object sensing transducer uses a plurality of individual transducers which are stationary relative to each other (for example eddy-current based surface transducers), and a selector unit. The individual transducers are, for example, mounted in a plane parallel to the surface of the test object to be sensed and scan the test object with respect to a characteristic, for example a crack. The resultant simulated transducer signal is signal processed by means of, for example, automatic compensation and vector transformation techniques.Type: GrantFiled: November 9, 1989Date of Patent: May 5, 1992Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4945307Abstract: A device for detecting irregularities in the surface of an object comprises at least one transducer which is movable relative to the surface of the object and an associated signal-processing unit which receives and processes output signals generated by the transducer. The signal-processing unit includes two electrical circuits, the first circuit providing a signal A which is derived from the output signal from the transducer and the second circuit including an analog shift register to provide a signal B which is derived from the output signal from the transducer and which is time delayed relative to signal A. The signal-processing unit also includes means for combining signals A and B to provide a measuring signal C.Type: GrantFiled: November 3, 1986Date of Patent: July 31, 1990Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt Tornblom
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Patent number: 4853634Abstract: An electrical defect testing device for a non-magnetic test object, for example crack detection on hot continuously cast billets, is provided with means for detecting and suppressing the influence of disturbing magnetic regions of the object (e.g. regions of cold oxide scale). The device comprises at least one sensing transducer for harmful faults which is adapted to move relative to the test object. At least one detector is associated with the transducer for identifying the presence of magnetic material, and a blocking circuit is provided which, directly or indirectly, is controlled by the magnetic detector and is used for suppressing signals originating from a fault vector, for example a signal indicating a harmful fault. The presence of magnetic material can be detected using an eddy current technique.Type: GrantFiled: August 14, 1987Date of Patent: August 1, 1989Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4851774Abstract: An eddy current testing device for inspecting test objects, for example billets, with respect to surface defects, for example surface cracks, comprises at least one transducer/sensor, for example a surface transducer or surface transducer arrangement, which is made to scan the surface of the test object. The device is characterized in that the effect of harmless surface blemishes on the testing device is suppressed, at least partially, by compensating for the sensitivity characteristic, in the scan direction of the transducer/sensor, with respect to the surface defect.Type: GrantFiled: July 13, 1987Date of Patent: July 25, 1989Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Device for suppression and/or separation of signals due to magnetic oxide scales in hot cast billets
Patent number: 4837510Abstract: Defect detecting equipment includes a device which detects the presence of, for example, disturbing magnetic material such as cold oxide scales in a test object, in order thus to control, for example, that disturbances of a magnetic origin are not confused with surface cracks without being discovered. By utilizing eddy current techniques, phenomena which are harmless to the process can be separated from dangerous surface cracks, thus avoiding the scrapping of crack-free test objects. The invention is based on signal-processing at least two signals, for example H1 and L1, originating from a test object sensing tansducer, by means of a vector transformation method, and distinguished between harmful and harmless phenomena (e.g. cracks and oxide scales) as a function of a comparison of signals, S1 and S2l , from at least two transformation blocks.Type: GrantFiled: January 20, 1988Date of Patent: June 6, 1989Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom -
Patent number: 4819181Abstract: A testing device for storing and/or processing of fault signals obtained from at least one transducer with associated electronic equipment, which fault signals are at least partially derived from one or more features, for example a defect on a test object, such as a steel blank. The fault signals are supplied to at least one discriminating circuit to distinguish between relevant and trivial fault signals. The relevant signals are then supplied to a plurality of different signal processing circuits which, for example, operate in parallel but independently.Type: GrantFiled: April 15, 1987Date of Patent: April 4, 1989Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4816760Abstract: A method and apparatus for use with a measuring and/or control device having at least one sensor based on eddy current induction and movable over a test piece and supplied with at least two carrier frequency signals. A determination is made on one of the carrier frequency signals with respect to those signal changes obtained at the transistion from measuring against the test piece to measuring against essentially empty space. When such signal changes occur an edge signal is generated which indicates that the measuring and/or control device has passed over an edge of the test piece.Type: GrantFiled: October 8, 1986Date of Patent: March 28, 1989Assignee: Asea AB & Tornbloms Kvalitetskontroll ABInventors: Lennart Svegander, Bengt Tornblom
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Patent number: 4789828Abstract: A device for quality testing hot test objects, comprises at least one coolant-cooled rotatable body, and at least one transducer (for example a surface transducer coil) eccentrically mounted in or on the body to move along an endless path in close proximity to a surface of the test object. The transducer is conncted directly or indirectly to an associated sensing circuit. A device according to the invention is characterized in that the flow of coolant is adapted to take place via an inlet channel and an outlet channel, both of which are disposed close to the axis of rotation of the body, and at least one further channel extending between the inlet and outlet channel to convey coolant at least close to the transducer(s).Type: GrantFiled: April 13, 1987Date of Patent: December 6, 1988Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4734642Abstract: A device for transmission of signals between two units which are movable relative to each other without having to use rotating slip rings or the like. The signal transmitting conductors are disposed close to a point on the center axis of a rotating holder for the signal source. This results in minimum fatigue of the conductors, which in turn permits a long life of the conductors. The signal source is journalled in the holder and can be prevented from rotating around its center axis. The device can also be used to transmit a medium such as a coolant between two units.Type: GrantFiled: January 6, 1986Date of Patent: March 29, 1988Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4703265Abstract: A method for testing an electrically conductive test object with regard to an imperfection therein uses a transducer supplied with drive signals of two different frequencies so that via inductive coupling between the transducer and the test object, signal information is received from the transducer which can be processed to indicate the presence of an imperfection. The invention is characterized in that the transducer is designed and supplied with drive signals in such wise that the effect of the different depth penetration of currents induced in the test object at the two frequencies can be compensated for.Type: GrantFiled: February 15, 1985Date of Patent: October 27, 1987Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4661777Abstract: In the testing of electrically conductive test objects for the presence of flaws and the like using a transducer to generate electrical currents in the test object and to inductively sense such currents, drive signals of at least two different frequencies are use for the transducer and the different frequency component induced signals picked up by the transducer are processed in such ways that a testing process is obtained that has low LO (lift-off) dependence. The characterizing feature of the invention is that the signal processing is undertaken as a function of at least one variable which may be the lift-off distance.Type: GrantFiled: February 8, 1985Date of Patent: April 28, 1987Assignee: Tornbloms Kvalitetskontroll ABInventor: Bengt H. Tornblom
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Patent number: 4237419Abstract: A method and device for nondestructive testing of articles using the eddy principle current and multifrequency technique. The characteristic feature is that the measurement is generally independent of the position of the article to be tested in relation to the pickup probe. In comparison with known devices the present device is easy to handle.Type: GrantFiled: June 7, 1978Date of Patent: December 2, 1980Assignee: Tornbloms Kvalitetskontroll ABInventors: Bengt H. Tornblom, Torborg M. Tornblom