Interpretation ID: nht95-1.20

TYPE: INTERPRETATION-NHTSA

DATE: January 10, 1995

FROM: Paul N. Wagner -- President, Bornemann Products Incorporated

TO: Philip R. Recht -- Chief Counsel, NHTSA

TITLE: Ref: Your letter dated December 23, 1994, copy enclosed

ATTACHMT: ATTACHED TO 3/21/95 LETTER FROM PHILIP RECHT TO PAUL N. WAGNER (A43; STD. 207)

TEXT: Dear Mr. Recht:

Thank you very much for your response to my questions concerning seating systems, FMVSS # 207. I would like to expand this inquiry somewhat further, and request a clarification accordingly, so as to eliminate any doubt on the issue of integrated seats.

For definition's sake, an integrated seat will refer to a seating system having the seat belts mounted to the seating structure, with the "D ring" mounting located on the seat back itself (instead of the wall pillar as most vehicles have today).

To clarify the issue of FMVSS # 207 static testing, it is clear that the only adjusted position exception is the vertical movement of nonlocking suspension seats while loads are applied. You have also made it very clear that the seating structure may be tested in any adjusted position, however there is still another question.

In order to be specific, if an integrated seat is tested to FMVSS # 207, when the loads are applied, a rachet-style seat recliner mechanism may not have its adjustment teeth shear during the test, since the seat must maintain its adjusted position, and t he shearing of the recliner teeth is an adjustment change. Is this supposition correct, assuming that the shearing of the recliner's teeth is a change in detent position?

The premise above does allow for normal structure deformation that does not change the detent position.

Lastly, a question that was not proposed earlier concerns continuous engagement, which simply implies that the seat recliner or slides will always be in a locked position, even during adjustment. Some slides and recliners, for adjustment purposes, must be "unlocked," or released, allowing for the adjustment to be made, but then automatically relock when the desired position is achieved; this adjustment method is not considered to be as continuously engaged, since the mechanism is in a released state du ring adjustment.

An apparatus that might be considered to be a continuous engagement device might be a screw-drive mechanism, which can be adjusted by revolution, but would always have a locking feature, even during adjustment (and never be in a released position).

Must a seat recliner or seat slides have "continuous engagement," in order to comply with FMVSS # 207/# 208/# 210 specifications on integrated seating? What this question addresses is the time frame when a seat recliner or seat slide may be disengaged, or released, during use while a vehicle is in motion, since the seat is not locked at these adjustment times, and the seat belt system is attached completely to the seating system.

I apologize for the continued questioning on this issue, and hope for your earliest response.

Thank you very much for your consideration of the above matters, as it is very much appreciated. If I can be of service, please feel free to contact me at your convenience.

Again, our thanks for your help!