Document ID: chunk:federal_register_of_legislation:F2012C00357:front:0:p48
Version: federal_register_of_legislation:F2012C00357
Segment Type: other
Provision Reference: 
Character Range: 128294–130862

enable the retractor to be tilted to the angle prescribed by the manufacturer;

      Shall be located on the arc of a circle with radius KB1 = 790 mm if the length between the upper strap guide and the strap outlet at the retractor is not less than 540 mm or, in all other cases, on the arc of a circle with centre K and radius 350 mm.

      4. STOPPING DEVICE

      4.1. The device consists of two identical absorbers mounted in parallel, except in the case of restraint systems when four absorbers shall be used for a nominal mass of 800 kg.  If necessary, an additional absorber shall be used for each 200 kg increase of nominal mass.  Each absorber comprises:

      an outer casing formed from a steel tube;

      a polyurethane energy‑absorber tube;

          a polished‑steel olive‑shaped knob penetrating into the absorber; and

      a shaft and an impact plate.

      4.2. The dimensions of the various parts of this absorber are shown in the diagrams reproduced in figures 2, 3 and 4.

      4.3. The characteristics of the absorbing material are given in table 1 of this annex.  Immediately before each test the tubes shall be conditioned at a temperature between 15° and 25 °C for at least 12 hours without being used.  During the dynamic testing of safety‑belts or restraint systems, the stopping device shall be at the same temperature as during the calibration test, with a tolerance of + 2 °C.  The requirements to be met by the stopping device are given in Annex 8 to this Regulation.  Any other device giving equivalent results may be used.

Table 1

CHARACTERISTICS OF THE ABSORBING MATERIAL

(ASTM Method D 735 unless otherwise stated)

Shore hardness A: 95 + 2 at 20 + 5 °C temperature

Breaking strength: Ro > 343 daN/cm2

Minimum elongation: Ao > 400 per cent

Module at 100 per cent elongation: > 108 daN/cm2

at 300 per cent elongation: > 235 daN/cm2

Low‑temperature brittleness (ASTM Method D 736): 5 hours at ‑55 °C

Compression set (Method B): 22 hours at 70 °C < 45 per cent

Density at 25 °C: between 1.05 and 1.10

Ageing in air (ASTM Method D 573)

 70 hours at 100 °C ‑ Shore‑A‑hardness:  max variation + 3

  ‑ breaking strength:  decrease < 10 per cent of Ro

  ‑ elongation:  decrease < 10 per cent of Ao

  ‑ mass:  decrease < 1 per cent

Immersion in oil (ASTM Method No. 1 Oil):

 70 hours at 100 °C ‑ Shore‑A‑hardness:  max variation + 4

  ‑  breaking strength:  decrease < 15 per cent of Ro

  ‑  elongation:  decrease < 10 per cent of Ao

  ‑  volume:  swelling < 5 per cent

Immersion in oil (ASTM Method No. 3 Oil):