Interpretation ID: nht73-5.19

DATE: 03/09/73

FROM: AUTHOR UNAVAILABLE; Richard B. Dyson; NHTSA

TO: General Motors Corporation

TITLE: FMVSS INTERPRETATION

TEXT: This is in reply to your letter of February 8, 1973, concerning the use of a "comfort clip" on the shoulder belt portion of GM's 1974 seat belt system.

In response to questions from other manufacturers concerning the use of high friction buckles in continuous loop belt systems, we have indicated that the requirement of Standard 208 that the belts adjust to fit specified occupants precludes the use of such buckles. In the case of systems with separate lap and shoulder belt retractors, however, the shoulder belt does not affect the tension in the lap belt and therefore does not present the risk of submarining that exists with the single loop systems. Accordingly, we are of the opinion that a comfort clip would be acceptable under S7.1.1 of the standard, so long as the shoulder belt is otherwise capable of adjustment as required by S7.1.1.

At a meeting with you on this subject on January 24, 1973, the NHTSA expressed its concern about possible reductions in shoulder belt effectiveness due to excessive belt slack. On the whole, we find that this possibility is more than offset by the prospects of greater usage due to the added convenience of the system with the clip. However, we strongly support your proposal to include instructions for the use of the clip both on the clip itself and in the owner's manual.