Interpretation ID: nht95-1.99

TYPE: INTERPRETATION-NHTSA

DATE: March 13, 1995

FROM: Dietmar K. Haenchen -- Manager, Vehicle Regulations, VOLKSWAGEN OF AMERICA, INC.

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

TITLE: Request for Information, FMVSS No. 118 "Power Operated Window, Partition and Roof Panel Systems"

ATTACHMT: ATTACHED TO 5/17/95 LETTER FROM JOHN WOMACK TO DIETMAR K. HAENCHEN (A43; STD. 118)

TEXT: Dear Mr. Recht:

This is a request for interpretation relating to the maximum squeezing force requirement in Paragraph S5 of FMVSS 118. Paragraph S5 states the maximum squeezing force performance requirements required to be met by power-operated window, partition or roo f panel systems (for simplicity we will hereinafter refer to these as "power operated systems") which are capable of being closed under conditions other than those permitted in Paragraph S4, Operating Requirements.

The purpose of Paragraph S5 is to enable manufacturers to provide power operated systems which can be closed with remote control devices capable of operation beyond the distances specified in S4 or under circumstances other than those expressly limited i n Paragraph S4 by providing an automatic reversing system that limits the squeezing force to 100 Newtons. The intent of the 100 Newton squeezing force limitation in Paragraph S5 is to avoid injury to a person whose hand may be caught in the opening of t he power operated system as it is closing.

The 100 Newton force limitation is a restriction on power-operated window and roof panel systems which must be assured of closing under all environmental conditions and especially under low temperatures or in the event of some ice or other interference i n the track of the window or roof panel. Volkswagen requests your interpretation whether a system which reverses the closing of the window partition or roof panel within the 100 Newton limitation on an initial attempt to close, but which is then capable of closing with a higher force limitation in order to overcome any resistance due to low temperature or snow and ice interference conditions would still comply with the provisions of the standard.

Such a system would operate as follows:

1. An attempt is made to close the power-operated system and because of an obstruction or resistance to closing it reverses before exerting a squeezing force of 100 Newtons or more and then stops.

2. In order to assure that the window or roof panel is closed, the operator again initiates the closing and this time the automatic reversal system is not triggered at the 100 Newton limit but at a higher force level to overcome the resistance.

The intent of the Standard and to requirement of paragraph S5 is that in the event of an initial obstruction from a human hand or possibly a pet, the system would reverse within the injury avoidance threshold of 100 Newtons. There is no specific provisi on in paragraph S5 with regard to repetitive closing operations. (The higher force level of the second closing operation is not a safety concern because the operator would be alerted to avoid action until the opening is clear and any person in the area w ould be alerted to the fact that the operator is attempting to close the window or roof panel.) Volkswagen therefore requests your interpretation whether the squeezing force limitation of Paragraph S5 applies only to the first operation of a system and n ot to subsequent operations immediately thereafter, which are separately initiated by an operator in order to assure the closing of the roof panel or power window under adverse conditions such as low temperature or the presence of ice in the window or ro of panel track.

Because the issue relates to certain vehicle design decisions, your response as soon as possible is requested and will be appreciated.