Title 49

SECTION 572.145

572.145 Upper and lower torso assemblies and torso flexion test procedure.

§ 572.145 Upper and lower torso assemblies and torso flexion test procedure.

(a) The test objective is to determine the resistance of the lumbar spine and abdomen of a fully assembled dummy (drawing 210-0000) to flexion articulation between upper and lower halves of the torso assembly (refer to § 572.140(a)(1)(iv)).

(b)(1) When the upper half of the torso assembly of a seated dummy is subjected to a force continuously applied at the occipital condyle level through the rigidly attached adaptor bracket in accordance with the test procedure set out in paragraph (c) of this section, the lumbar spine-abdomen assembly shall flex by an amount that permits the upper half of the torso, as measured at the posterior surface of the torso reference plane shown in Figure P5 of this subpart, to translate in angular motion in the midsagittal plane 45 ±0.5 degrees relative to the vertical transverse plane, at which time the pulling force applied must not be less than 130 N (28.8 lbf) and not more than 180 N (41.2 lbf), and

(2) Upon removal of the force, the upper torso assembly returns to within 10 degrees of its initial position.

(1) Soak the dummy in a controlled environment at any temperature between 18.9° and 25.6 °C (66 and 78 °F) and at any relative humidity between 10 and 70 percent for at least 4 hours prior to a test.

(2) Assemble the complete dummy (with or without the lower legs) and seat it on a rigid flat-surface table, as shown in Figure P5 of this subpart.

(i) Unzip the torso jacket and remove the four 1/4-20 × 3/4″ bolts which attach the lumbar load transducer or its structural replacement to the pelvis weldment (drawing 210-4510) as shown in Figure P5 of this subpart.

(ii) Position the matching end of the rigid pelvis attachment fixture around the lumbar spine and align it over the four bolt holes.

(iii) Secure the fixture to the dummy with the four 1/4-20 × 3/4″ bolts and attach the fixture to the table. Tighten the mountings so that the pelvis-lumbar joining surface is horizontal within ±1 deg and the buttocks and upper legs of the seated dummy are in contact with the test surface.

(iv) Attach the loading adapter bracket to the upper part of the torso as shown in Figure P5 of this subpart and zip up the torso jacket.

(v) Point the upper arms vertically downward and the lower arms forward.

(3)(i) Flex the thorax forward three times from vertical until the torso reference plane reaches 30 ±2 degrees from vertical. The torso reference plane, as shown in figure P5 of this subpart, is defined by the transverse plane tangent to the posterior surface of the upper backplate of the spine box weldment (drawing 210-8020).

(ii) Remove all externally applied flexion forces and support the upper torso half in a vertical orientation for 30 minutes to prevent it from drooping.

(4) Remove the external support and after two minutes measure the initial orientation angle of the upper torso reference plane of the seated, unsupported dummy as shown in Figure P5 of this subpart. The initial orientation of the torso reference plane may not exceed 15 degrees.

(5) Attach the pull cable at the point of load application on the adaptor bracket while maintaining the initial torso orientation. Apply a pulling force in the midsagittal plane, as shown in Figure P5 of this subpart, at any upper torso flexion rate between 0.5 and 1.5 degrees per second, until the torso reference plane reaches 45 ±0.5 degrees of flexion relative to the vertical transverse plane.

(6) Continue to apply a force sufficient to maintain 45 ±0.5 degrees of flexion for 10 seconds, and record the highest applied force during the 10-second period.

(7) [Reserved]

(8) Release all force at the loading adaptor bracket as rapidly as possible and measure the return angle with respect to the initial angle reference plane as defined in paragraph (c)(4) of this section 3 to 4 minutes after the release.