Interpretation ID: 1984-2.14

TYPE: INTERPRETATION-NHTSA

DATE: JULY 3, 1984

FROM: AUTHOR UNAVAILABLE; Frank Berndt; NHTSA

TO: Schnader; Harrison; Segal & Lewis

TITLE: FMVSS INTERPRETATION

TEXT: This responds to your letter of May 9, 1984, concerning the application of Standard No. 208, Occupant Crash Protection, and Standard No. 209, Seat Belt Assemblies, to an emergency locking retractor designed by one of your clients. The following discussion addresses the application of those standards to the retractor.

You explained that the purpose of the new emergency locking retractor (ELR) is to facilitate the securing of a child restraint in a vehicle. The ELR would only be installed in forward-facing passenger seating positions. The new ELR is designed so if the belt is pulled all the way out of the retractor, the ELR will convert into an automatic locking retractor (ALR). Once all but 1393-1493 mm of the belt retracts, the retractor will revert automatically to the ELR mode.

You further explained that the continuous loop lap and upper torso belt used with this retractor is 380 mm longer than the belt system provided for the driver's seating position. You explained that the extra 380 mm of belt webbing is meant "to permit normal occupant movement without inadvertent actuation of the ALR mode while still rendering it convenient for manual extension when the ALR mode is desired for child restraint use."

You specifically asked whether the retractor designed by your client would be considered an ELR for the purposes of S7.1.1 of Standard No. 208. In addition, you asked about the retractor durability tests of S5.2(k) of Standard No. 209. As a part of that test, a retractor is subjected to "45,000 additional cycles of webbing withdrawal and retraction between 50 and 100 percent extension." You asked whether, for the purposes of the section 5.2(k) test, the length of the driver's belt, which is 380 mm shorter than the passenger's belt, could be used to determine what constitutes 100 percent extension of the belt. You alternatively asked whether the test could be stopped before complete extension of the passenger belt.

As we understand your client's seat belt assembly, the amount of webbing in the driver's side assembly complies to the adjustment requirements of section 4.1(g) of Standard No. 209. The 380 mm's of extra webbing that is included in the passenger's seat belt assembly has been voluntarily added as a precaution to reduce the possibility of an occupant inadvertently actuating the ALR mode of the retractor. Based on the information you have provided, it appears that in normal operation by occupants covered by the adjustment requirements of Standard No. 209 the retractor functions exclusively as an ELR and thus can be used to meet the requirements of S7.1.1 of Standard No. 208. The agency views the 380 mm's of extra webbing as a voluntary addition not required by the standard. Therefore, for the purpose of section 5.2(k) of Standard No. 209, the agency will use the length of the driver's belt to determine what constitutes full extension of the webbing.

Sincerely,

ATTACH.

May 9, 1984

Diane Steed -- Administrator, National Highway Traffic Safety Administration

Interpretation of FMVSS 208 & 209 re: Emergency Locking Retractors

Dear Ms. Steed: On March 19, 1984, I met with Messrs. Hitchcock, Hunter, Smith and Nelson from the Office of Rulemaking and Mr. Gilkey from the Office of Enforcement to demonstrate a new design of emergency locking retractor that one of our clients will soon introduce on a new car in the United States. This innovative design addresses the problem of fitting a child seat to a seated position fitted with a seat belt equipped with an emergency locking retractor (ELR) rather than an automatic locking retractor (ALR). Many owners (and NHTSA) have expressed concern that a child seat may not be securely restrained by an ELR, or at least the vehicle operator may be unsure of the ELR's ability to secure the seat during normal vehicle operation, such as sudden stops or quick turns.

Our client has designed a unique ELR that automatically temporarily converts to an ALR mode to facilitate the fitting of a child seat. This is accomplished by merely pulling the belt all the way out of the retractor, at which point a click is heard, and the ELR converts to an ALR mode until the belt is again retracted back into the retractor. Once all but 1393-1493 mm of the belt retracts, the retractor reverts automatically to the normal ELR mode. This seat belt assembly, consisting of a slightly longer running loop combination lap and upper torso belt and the new ELR, will be installed only in forward-facing passenger seat positions -- not the driver's seat.

Paragraph S4.1.2.3.1(a) of FMVSS 208 requires the applicable vehicle to "have a seat belt assembly that conforms to S7.1 and S7.2." S7.1.1 requires an upper torso restraint furnished in accordance with S4.1.2.3.1(a) to "adjust by means of an emergency-locking retractor that conforms to Standard No. 209." We believe that the retractor described herein and demonstrated to NHTSA on March 19, 1984 meets that requirement. That is to say that an ELR that is temporarily convertible to an ALR mode is still an ELR for the purpose of FMVSS 208.

Paragraph S5.2(k) of FMVSS 209 specifies requirements for retractor performance. As part of the durability requirements, an ELR "attached to upper torso restraint shall be subjected to 45,000 additional cycles of webbing withdrawal and retraction between 50 and 100 percent extension." The subject ELR cannot be tested to exactly 100 percent extension without engaging the ALR mode. This would, of course, lock the belt when it is stopped at the 50 percent point and prevent its re-extension without retraction to within 255-355 mm of being completely retracted. An additional 380 mm of webbing is provided in this installation. This amount was selected as the optimum to permit normal occupant movement without inadvertent actuation of the ALR mode while still rendering it convenient for manual extension when the ALR mode is desired for child seat use. We feel it appropriate that this retractor be tested to the applicable portions of S5.2(k) using 50 to 100 percent of the belt length of the driver's belt, which is 38) mm shorter. Alternatively, if the 100 percent requirement is a nominal value only, the test could be stopped just before full extension to preclude unwanted conversion to the ALR mode during the retractor test.

We would appreciate your early confirmation of our understanding that this unique emergency locking retractor design complies with these paragraphs of FMVSS 208 and 209. Should for some reason you disagree with our interpretation, please treat this as a Petition for Rulemaking to amend such portions of the applicable standards as necessary to permit the use of what we believe to be an important and desirable safety innovation.

Sincerely, Donald M. Schwentker -- SCHNADER, HARRISON, SEGAL & LEWIS