Interpretation ID: 2971yy
General Motors Corporation Legal Staff
New Center One Building
3031 West Grand Blvd.
P.O. Box 33122
Detroit, MI 48232
Dear Mr. Toth:
This responds to your request for an interpretation of how the requirements of Standard No. 209, Seat Belt Assemblies (49 CFR 571.209) would affect some dual-spring retractor designs GM is considering. Your letter said that these dual-spring retractors are designed so that a spring with a lower retraction force is or can be engaged when the safety belt is being worn by an occupant. When the safety belt is removed, a spring with a higher retraction force is engaged to effectively stow the belt webbing. Your letter also said that the retractor for the shoulder belt portion of the lap/shoulder belts on which these designs would be used is an emergency locking retractor (ELR).
The minimum and maximum retractor force requirements for ELRs are set forth in S4.3(j)(5) and (6) of Standard No. 209. Those sections specify minimum and maximum retractor force requirements when the retractors "are tested in accordance with the procedures specified in paragraph S5.2(j)." S5.2(j) specifies that, for the purposes of measuring the retractor forces, the webbing shall be fully extended from the retractor and then retracting the webbing to 75 percent extension plus or minus 2 inches.
Your letter stated that your dual-spring retractor designs will comply with the minimum retractor force requirements when tested under the conditions specified in S5.2(j). This is because the higher retraction force will always be engaged under those conditions. It appears that, when the higher retraction force is engaged in these dual-spring retractor designs, the retractors will comply with the minimum retractor force requirements. However, when the lower retraction force is engaged, the retractor force is less than the minimum retractor force requirement. Because these dual-spring retractors comply with the retractor force requirements when tested under the conditions specified in S5.2(j) of Standard No. 209, your company is ready to certify these designs as complying with Standard No. 209.
You are, however, concerned with the implications of a February 16, 1984 NHTSA interpretation addressed to Mr. Frank Pepe. In that instance, Mr. Pepe stated that the ELR had two tension modes that were activated by the vehicle door. The subject retractor operated in a high tension mode when the vehicle door was open, and in a lower tension mode when the vehicle door was closed. The agency concluded that, because Standard No. 209 does not distinguish between tension modes, the subject retractors would have to comply with all the requirements of the standard, including the minimum and maximum retraction force requirements, in both tension modes. Your letter asked us to reevaluate the conclusions reached in our February 16, 1984 letter to Mr. Pepe.
We believe that the facts presented in your letter are significantly different than those that were presented in the Pepe letter, so the conclusions reached in the Pepe letter are not the same we would reach for your company's dual-spring retractors. In the case of the Pepe letter, the starting point for our analysis of whether the retractors would comply with the minimum and maximum retractor force requirements was the language of S4.3(j) in Standard No. 209, which directed us to the test conditions set forth in S5.2(j) of Standard No. 209. However, the test conditions in S5.2(j) [complete extension of the webbing, followed by subsequent retraction to 75 percent extension] did not adjust the Pepe retractors to either the high or low tension mode. Some additional action beyond the conditions specified in S5.2(j) had to be taken to select either the high or low tension mode. Since the selection of the high or low tension mode was not specified in S5.2(j) or elsewhere in Standard No. 209, NHTSA concluded that the retractor would have to be certified as complying with the retractor force requirements when adjusted to either the high or low tension mode.
The GM retractors present a significantly different situation. According to your letter, the conditions set forth in S5.2(j) will adjust the GM retractors in a way so that the higher retraction force will always be engaged. Assuming this to be the case, no adjustments beyond the conditions specified in S5.2(j) would be necessary to select a tension mode for the retractors. In these circumstances, compliance with the minimum retractor force requirements would be determined only under the conditions specified in S5.2(j).
Sincerely,
Paul Jackson Rice Chief Counsel
ref:209 d:4/9/9l