TEST DEVICE FOR CARRYING OUT 4-POINT BEND CHANGING TESTS

摘要

The invention relates to an apparatus for carrying out 4-point alternating bending stress tests on specimens, in particular printed circuit boards. …??The testing apparatus comprises two hinges (1,2) which move in the same direction, preferably vertically, and which are located between two fixed hinges (3, 4). All the hinges 1-4) are provided with holders (5-8), the holders (7, 8) of the fixed hinges (3, 4) being attached to the lower specimen mounting of a universal materials testing machine via a base plate (10) and the holders (5, 6) of the movable hinges (1, 2) being attached to a plate (11) which can be moved with respect to the base plate (10) and which is firmly clamped in the upper specimen mounting of the materials testing machine. The hinges (1-4) each comprise a pair of rollers (20, 21) which is rotatably mounted around a common axis of rotation (13, 23, 33, 43) in the respective associated holder (5-8). The specimen (9) to be examined is between the rollers of the individual pairs of rollers (20, 21). The rollers (20, 21) themselves are each mounted rotatably about their longitudinal axis (201, 211). The pairs of rollers (20, 21) are mounted so as to be inherently adjustable and adjustable with respect to one another in such a way that the specimen (9) can be clamped in a play-free and tensile-stress-free manner even while the alternating bending test is being carried out. …IMAGE…