Improvement of the automatic belt:​ the possible efficiency of the pyrotechnical retractor

Dejeammes, Maryvonne; Biard, Roger; Derrien, Yves

Affiliations

¹Laboratoire des Chocs et de Biomecanique-ONSER

Abstract

The pyrotechnical retractor is a new device designed for reducing the adverse "film spool" of the classical retractor and for improving the occupant-vehicle coupling in case of three point belt restraint.

This study objective is to quantify the improvements afforded by the pyrotechnical retractor from dynamic tests simulating a frontal crash at 50 km/h with a part 572 dummy. It appears that the working of the pyrotechnical retractor is all the more efficient as the ignition time is shorter but the retraction phase is hardly influenced by the length of wheeled webbing. The comparison with an usual retractor belt in identical test conditions shows a sensitive benefit afforded by the pyrotechnical retractor, mainly on the maximum dummy displacement and the head severity index. Moreover, the pyrotechnical retractor gives a better protection in the case of clothes wearing or belt slack.

Cited Works (2)

Year	Entry
1976	Quincy R, Dejeammes M. Analysis of the preloaded safety belt restraint with an animal. In: 20th Annual Proceedings, Association for the Advancement of Automotive Medicine (AAAM). November 1-3, 1976; Atlanta, GA.60-72.
1977	Hontschik H, Müller E, Rüter G. Necessities and possibilities of improving the protective effect of three-point seat belts. In: Proceedings of the 21st Stapp Car Crash Conference. October 19-21, 1977; New Orleans, LA. Warrendale, PA: Society of Automotive Engineers:795-831. SAE 770933.