Interpretation ID: nht76-5.1

DATE: 01/23/76

FROM: AUTHOR UNAVAILABLE; R. B. Dyson; NHTSA

TO: AB Stil-Industri

TITLE: FMVSS INTERPRETATION

TEXT: This responds to Stil-Industri's December 12, 1975, question whether S5.2(d)(1) of Standard No. 209, Seat Belt Assemblies, specifies, in the case of a push-button release, the location and direction of force application used in testing the release under the requirements of S4.3(d)(1). Section S5.2(d)(1) provides in part:

(1) . . .The buckle release force shall be measured by applying a force on the buckle in a manner and direction typical of those which would be employed by a seatbelt occupant. For pushbutton-release buckles, the force shall be applied at least 0.125 inch from the edge of the push-button access opening of the buckle in a direction that produces maximum releasing effect. . .

The NHTSA interprets these provisions of S5.2(d)(1) to permit the manufacturer to apply force in the direction and location that provides the best possible mechanical advantage relative to the manufacturer's buckle design. The only limitation in the case of a push-button design is that the manufacturer must not apply the force any closer than 0.125 inch from the edge of the push-button access opening.

Yours truly,

ATTACH.

CHIEF COUNSEL -- NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION

DECEMBER 12, 1975

GENTLEMEN,

WE ARE A SWEDISH COMPANY PRODUCING SAFETY-BELTS FOR DIFFERENT CARS AND ALL DIFFERENT MARKETS. WE WOULD KINDLY ASK YOU TO HELP US WITH SOME QUESTIONS WE HAVE ABOUT HOW TO INTERPRET SECTION (1) IN S.5.2 (D) ABOUT BUCKLE RELEASE.

FROM THE PASSAGE: "THE BUCKLE RELEASE FORCE SHALL BE. . . . .TO:. .. RELEASING EFFECT". WE WOULD LIKE TO ASK YOU THE FOLLOWING QUESTIONS. WHERE ON THE PUSH BUTTON SHALL WE APPLY THE FORCE? IN A POSITION WHICH IS TYPICAL FOR THE SEAT BELT OCCUPANT? IN THE CENTER? 1/8 INCH FROM WHICH EDGE? IN WHAT DIRECTION? THESE QUESTIONS ARE OF GREAT IMPORTANCE FOR US AND WE AWAIT YOUR REPLY WITH GREAT INTEREST. WE ARE VERY GREATFUL IF YOU COULD ANSWER AS SOON AS POSSIBLE.

SINCERELY YOURS AB STIL-INDUSTRI; HANS SYLVEN -- CHIEF OF CONSTRUCTION