Document ID: chunk:federal_register_of_legislation:F2015C00542:reg:52:p3
Version: federal_register_of_legislation:F2015C00542
Segment Type: reg
Provision Reference: reg 52 (pt 3/6)
Character Range: 87553–90471

case care shall be taken to ensure adequate contact between the safety glazing pane and the support.

              2.2.4. Procedure

               Condition the test piece at the specified temperature for at least four hours immediately preceding the test.

                Place the test piece in the fixture (paragraph 2.1.1.3.). The plane of the test piece shall be perpendicular, within 3°, to the incident direction of the ball.

               In the case of glass-plastics glazing the test piece shall be clamped to the support.

               The point of impact shall be within 25 mm of the geometric centre of the test piece.

               The ball shall strike that face of the test piece which represents the inward face of the safety-glass pane when the latter is mounted on the vehicle.

               The ball shall be allowed to make only one impact.

              3. Headform test

              3.1. Headform test without deceleration measurement

              3.1.1. Apparatus

               Headform weight with a spherical or semi-spherical headform made of laminated hardwood covered with replaceable felt and with or without a cross-beam made of wood. There is a neck-shaped intermediate piece between the spherical part and the cross-beam and a mounting rod on the other side of the cross-beam.

               The dimensions shall be in accordance with Figure 2. The total mass of the apparatus shall be 10 kg ± 0.2 kg.

Figure 2

Headform weight

              3.1.2. Means for dropping the headform weight freely from a height to be specified, or means for giving the weight a velocity equivalent to that obtained by the free fall. When a device to project the headform weight is used, the tolerance on velocity shall be ±1 per cent of the velocity equivalent to that obtained by the free fall.

              3.1.3. Supporting fixture, as shown in Figure 3, for testing flat test pieces. The fixture is composed of two steel frames, with machined borders 50 mm wide, fitting one over the other and faced with rubber gaskets about 3 mm thick and 15 mm ± 1 mm wide and of hardness 70 IRHD. The upper frame is held pressed against the lower frame by at least eight bolts.

              3.1.4. Test conditions

               Temperature:  20 °C ± 5 °C

               Pressure:  860 to 1,060 mbar

               Relative humidity: 60 ± 20 per cent.

              3.1.5. Procedure

              3.1.5.1. Test on a flat test piece

               The flat test piece, having a length of 1,100 + 5/-2 mm and a width
              of 500 + 5/-2 mm, shall be kept at a constant temperature of 20 °C ± 5 °C for at least four hours immediately preceding the test.

Figure 3

Support for headform tests
       [9]

               Fix the test piece in the supporting frames (paragraph 3.1.3.); the torque on the bolts shall ensure that the movement of the test piece during