Document ID: chunk:federal_register_of_legislation:F2017C00972:body:0:p18
Version: federal_register_of_legislation:F2017C00972
Segment Type: other
Provision Reference: 
Character Range: 47514–50268

considered to be satisfied if, at the request of the manufacturer, they are replaced by a collision test of the complete vehicle in running order against a rigid barrier as laid down in paragraph 2. of annex 7 to this Regulation.  In this case, the seat shall be adjusted for the least favourable conditions of distribution of stresses in the anchorage system as provided for in paragraphs 6.1.1., 6.3.3. and 6.3.4. above.

6.4. Test of the performance of the head restraint

        6.4.1. If the head restraint is adjustable, it shall be placed in the most unfavourable position (generally the highest position) allowed by its adjustment system.

        6.4.2. In the case of a bench seat, where part or all of the supporting frame (including that of the head restraints) is common to more than one seating position, the test shall be conducted simultaneously for all those seating positions.

6.4.3. Test

        6.4.3.1. All lines, including the projections of the reference line, shall be drawn in the vertical median plane of the seat or seating position concerned (see annex 5 to this Regulation).

        6.4.3.2. The displaced reference line is determined by applying to the part simulating the back of the manikin referred to in annex 3 to this Regulation an initial force producing a rearward moment of 37.3 daNm about the R point.

        6.4.3.3. By means of a spherical headform 165 mm in diameter an initial force producing a moment of 37.3 daNm about the R point is applied at right angles to the displaced reference line at a distance of 65 mm below the top of the head restraint, the reference line being kept in its displaced position in accordance with paragraph 6.4.3.2.

        6.4.3.3.1. If the presence of gaps prevents the application of the force prescribed in paragraph 6.4.3.3. at 65 mm from the top of the head restraint, the distance may be reduced so that the axis of the force passes through the centre line of the frame element nearest to the gap.

        6.4.3.3.2. In the cases described in paragraphs 5.8. and 5.9. above, the test shall be repeated by applying to each gap, using a sphere of 165 mm in diameter, a force:

         passing through the centre of gravity of the smallest of the sections of the gap, along transversal planes parallel to the reference line, and

         reproducing a moment of 37.3 daNm about the R point.

        6.4.3.4. The tangent Y to the spherical headform, parallel to the displaced reference line, is determined.

        6.4.3.5. The distance X, provided for in paragraph 5.11. above, between the tangent Y and the displaced reference line is measured.

        6.4.3.6. To check the effectiveness of the head restraint, the initial load specified in paragraphs 6.4.3.3.