US3927558A
Expired / Lapsed
US
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Determination of properties of metals
Assignee: Centre de Recherches Metallurgiques CRM ASBL
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Filing: 1973-10-11
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Granted: 1975-12-23
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Expires: 1993-10-11
Abstract
Abstract A horizontal tensile testing machine is used in combination with a coumputer. Both ends of the specimen are moved simultaneously at the same speed in opposite directions. Elongation and changes in width are measured simultaneously by two independent extensometric systems having a common centre of symmetry which coincides with the centre of symmetry of the specimen throughout the test. The test sequence is performed by the machine without direct intervention of an operator.
Inventors
- 👤 Leon Jean Philippe
- 👤 Rene Charles Defraye
- 👤 Lucien Paul Renard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:23
CPC Classifications
G; G01; G01N; G01N3/00; G01N3/08; G01N3/10; G01N3/28
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
221 words
A process for determining mechanical properties of a metal in the form of a flat tensile test specimen, using a tensile testing machine of the horizontal type, having detectors for measuring the load and variations in length and width of a flat measurement base of the specimen, in combination with a computer for processing of the measurement data, the process comprising the steps of: applying an identical tensile stress simultaneously from both ends of the specimen by means of two clamps engaged at opposite ends of the specimen and displacing them simultaneously at the same speed in opposite directions; and simultaneously measuring both the change in length and the change in width of the measurement base simultaneously by means of two extensometric systems which are movable independently of each other, locating and Maintaining the center of symmetry of these two systems so that they are the same and are continuously coincident, until the end of the test, with the center of symmetry of the specimen and on which the specimen is centered upon placing these two systems in contact with the specimen, whereby the tensile test sequence is performed by the tensile testing machine without direct intervention of an operator, except for placing the specimen in the clamps at the beginning of the test and for withdrawing the specimen after fracture.
Claim 2
Dependent Claim
221 words
A process for determining mechanical properties of a metal in the form of a flat tensile test specimen, using a tensile testing machine of the horizontal type, having detectors for measuring the load and variations in length and width of a flat measurement base of the specimen, in combination with a computer for processing of the measurement data, the process comprising the steps of: applying an identical tensile stress simultaneously from both ends of the specimen by means of two clamps engaged at opposite ends of the specimen and displacing them simultaneously at the same speed in opposite directions; and simultaneously measuring both the change in length and the change in width of the measurement base simultaneously by means of two extensometric systems which are movable independently of each other, locating and Maintaining the center of symmetry of these two systems so that they are the same and are continuously coincident, until the end of the test, with the center of symmetry of the specimen and on which the specimen is centered upon placing these two systems in contact with the specimen, whereby the tensile test sequence is performed by the tensile testing machine without direct intervention of an operator, except for placing the specimen in the clamps at the beginning of the test and for withdrawing the specimen after fracture.
Claim 3
Dependent Claim
49 words
A process as claimed in claim 1, in which, after the specimen has been placed in between the clamps, the initial stage of the test sequence comprises clamping the specimen in the clamps under a predetermined hydraulically applied pressure to prevent accidental displacement during application of the tensile stresses.
Claim 4
Dependent Claim
51 words
A process as claimed in claim 1, comprising applying a small tractive force to the specimen after clamping, without causing elongation and so that the force is sufficient to place the specimen under tension to correct the planeity of the surface of the specimen which is measured by the extensometric systems.
Claim 5
Dependent Claim
43 words
A process as claimed in claim 1, in which, after the specimen has been placed under tension, applying the extensometric systems in contact with a lower surface of the specimen by means of a thrust exerted upwards from below on the extensometric systems.
Claim 6
Dependent Claim
51 words
A process as claimed in claim 1, in which, when the extensometric systems are in position and ready for operation, applying traction to the specimen at a predetermined speed and maintaining this speed until the yield stress or the end of the yield point elongation of the specimen has been reached.
Claim 7
Dependent Claim
34 words
A process as claimed in claim 1, including increasing the speed of traction of the claims from a predetermined value maintained until the yield stress or the end of the yield elongation is reached.
Claim 8
Dependent Claim
32 words
A process as claimed in claim 1, in which the final stage of the test sequence consists of maintaining the traction speed equal to a predetermined value up to a maximum load.
Claim 9
Dependent Claim
53 words
A process as claimed in claim 1, in which, whilst clamping the specimen in the clamps, effecting the correct and decisive placing in position of the specimen by the displacement yield point a ball having a spherical surface situated in each clamp to establish tight contact with the upper surface of the specimen.
Claim 10
Dependent Claim
62 words
A process as claimed in claim 1, including effecting displacement of the two extensometric systems for the purpose of being placed in contact with the specimen at the beginning of the test or of their separation at the end of the test is performed on each occasion as a single operation by the displacement of a support common to the two systems.
Claim 11
Dependent Claim
41 words
A process as claimed in claim 1, including establishing contact of the extensometric system with the lower surface of the specimen by pressing pins, comprising a portion of the extensometric systems, by urging the pins into the surface of the specimen.
Claim 12
Dependent Claim
72 words
A process as claimed in claim 1, in which, during resetting of the extensometric systms, after fracture of the specimen, the correct spacing between the pairs of reference points of each system as well as the coincidence of the centers of symmetry of the two systems is established by the placing a spherical stop integral with one system in contact with the inner surface of a dihedron integral with the other system.
Claim 13
Dependent Claim
31 words
A process as claimed in claim 1, including providing an automatic control for the sequence of the stages of the tensile test and including a manual over-ride for the automatic control.
Claim 14
Dependent Claim
25 words
A process as claimed in claim 1, including effecting automatic control of the stages of the tensile test automatically by positive linkage to the computer.
Claim 15
Dependent Claim
142 words
Apparatus for determining mechanical properties of a metal in the form of a flat tensile test specimen, the apparatus comprising a horizontal tensile testing machine having detectors for measuring the load and the Changes in length and width of a measuring base of the specimen, and a computer linked with the detectors, and including in combination: a. a mechanism for application of an identical tractive stress at both ends of the specimen, comprising two clamps displaceable at the same time at the same speed and in opposite directions; b. means for measuring changes in length and width of the flat specimen comprising two extensometric systems each of which being displaceable independently of each other and each including a common center of symmetry substantially stationary throughout the test period; and c. means for controlling the mechanisms with which the traction machine is equipped.
Claim 16
Dependent Claim
142 words
Apparatus for determining mechanical properties of a metal in the form of a flat tensile test specimen, the apparatus comprising a horizontal tensile testing machine having detectors for measuring the load and the Changes in length and width of a measuring base of the specimen, and a computer linked with the detectors, and including in combination: a. a mechanism for application of an identical tractive stress at both ends of the specimen, comprising two clamps displaceable at the same time at the same speed and in opposite directions; b. means for measuring changes in length and width of the flat specimen comprising two extensometric systems each of which being displaceable independently of each other and each including a common center of symmetry substantially stationary throughout the test period; and c. means for controlling the mechanisms with which the traction machine is equipped.
Claim 17
Dependent Claim
102 words
Apparatus as claimed in claim 14, in which the mechanism for applying an identical tractive force at both ends of the specimen comprises a piston and cylinder device for load application and two guided spindles rigid with the corresponding clamps, one spindle being coupled to the piston including means so that displacement of the spindle occurs in the same direction as that of the piston, the other spindle being connected to the device by means so that the displacement of the spindle occurs in the opposite direction and with an amplitude equal to that of the displacement of the said one spindle.
Claim 18
Dependent Claim
90 words
Apparatus as claimed in claim 14, in which the means for measuring the changes in length and width comprises a twin extensometric system consisting on the one hand of two carriages bearing marking points integral with a length measuring detector, these two carriages being displaceable parallel to the axis of traction, aand two carriages bearing marking points integral with a width measuring detector, these two carriages being displaceable at right angles to the axis of traction, the centers of symmetry of the two systems coinciding on the axis of traction.
Claim 19
Dependent Claim
42 words
Apparatus as claimed in claim 14, in which the means for controlling the mechanisms with which the traction machine is equipped comprises two separate arrangements one of which providing manual control and the other of which providing automatic control by the computer.
Claim 20
Dependent Claim
15 words
Apparatus as claimed in claim 14, in which the computer is of the analog type.
Claim 21
Dependent Claim
15 words
Apparatus as claimed in claim 14, in which the computer is of the digital type.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |