TEST METHOD AND TOOL FOR TESTING FASTENED FASTENERS
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Accused Products
Abstract
A screw fastener testing method for verifying the status of a previously tightened screw fastener with respect to installed torque and actual torque growth per angle of rotation properties includes applying an increasing tightening torque on the fastener, measuring the torque magnitude at the start of rotation, of the fastener, measuring the rotational movement of the fastener after the start of rotation, calculating the torque growth per angle of rotation for a certain predetermined test interval of rotation from the start of rotation, comparing the torque magnitude indicated during rotation and the calculated torque growth per angle of rotation during the test interval of rotation with predetermined reference values (Tstart, KR) or (TE, KP), respectively, characteristic for the actual fastener when tightened to a desired target torque level, and approving or disapproving the fastener status in view of the reference values.
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Citations
27 Claims
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1-9. -9. (canceled)
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10. A screw fastener testing method for verifying the status of a previously tightened screw fastener with respect to installed torque and actual torque growth per angle of rotation properties, comprising:
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applying an increasing tightening torque on the fastener, in order to rotate said fastener, for accomplishing a test interval of rotation; measuring the torque magnitude during said test interval of rotation; measuring the rotational movement of the fastener during said test interval of rotation; calculating the torque growth per angle of rotation for said test interval of rotation; comparing the torque magnitude and the calculated torque growth per angle of rotation during said test interval of rotation with predetermined reference values characteristic for the actual fastener when tightened to a desired target torque level; and approving or disapproving the fastener status in view of said reference values. - View Dependent Claims (11, 12, 13, 19, 20, 21)
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14. A screw fastener testing tool for verifying the status of a previously tightened screw fastener with respect to installed torque and actual torque growth per angle of rotation properties, comprising:
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a device for applying increasing tightening torque on the fastener, in order to rotate said fastener, for accomplishing a test interval of rotation; a device for measuring the torque magnitude during said test interval of rotation; a device for measuring the rotational movement of the fastener during said test interval of rotation; a device for calculating the torque growth per angle of rotation for said test interval of rotation; a comparing unit for comparing the measured torque magnitude and the calculated torque growth per angle of rotation during said test interval of rotation with predetermined reference values characteristic for the actual fastener when tightened to a desired target torque level, and approving or disapproving the fastener status in view of said reference values. - View Dependent Claims (15, 16, 17, 18, 22, 23, 24, 25, 26, 27)
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Specification