Interpretation ID: nht81-2.11

DATE: 03/30/81

FROM: AUTHOR UNAVAILABLE; F. Berndt; NHTSA

TO: BMW of North America

TITLE: FMVSS INTERPRETATION

TEXT:

MAR 30 1981

NOA-30

Mr. Karl-Heinz Ziwica Manager Safety & Emission Control Engineering BMW of North America, Inc. Montvale, NJ 07645

Dear Mr. Ziwica:

This responds to your letter of February 13, 1981, requesting an interpretation of Safety Standard No. 127, Speedometers and Odometers. The odometer/speedometer assembly that BMW wishes to use in its vehicles is built to comply with S4.2.5.2, the encapsulation requirements. The encapsulation consists of plastic "box" having the speedometer/odometer face and lens as its front. The front, top, bottom, and sides of the box are all one piece. The back of the unit is a metal plate to which the speedometer/odometer assembly is attached. The plate is attached to the rest of the unit with six screws. You ask whether the screws must be encapsulated if the unit is to comply with S4.2.5.2. You also ask whether a seal that would have to be cut or torn in order to remove the plates and gain access to the odometer can be used.

Paragraph S4.2.5.2(b) of Standard No. 127 requires that a tamperer not be able to contact the odometer wheels by use of a straight rod .5mm or more in diameter. Such contact is permissible if the contact results when the rod is inserted essentially parallel to the odometer shaft, or if it is necessary either to penetrate the encapsulation or to damage the encapsulation or other odometer components to make that contact. Since your odometer/speedometer assembly is attached to the back plate, the odometer wheels can be easily reached from all angles without damaging the encapsulation when the plate is removed. Thus the screws must be encapsulated if the odometer is to comply with S4.2.5.2(b). If the screws are encapsulated in some fashion, it would be necessary to penetrate this encapsulation in order to remove the screws and the back plate, and the requirements of paragraph S4.2.5.2(b) would be satisfied.

Paragraph S4.2.5.2(d) sets forth the requirements for the encapsulation material. The rule specifies requirements for thickness and resistance to deflection, penetration, fracture, and impacts. The agency is not concerned about the form of the encapsulation as long as these requirements are met.

We hope you find this information helpful. Please contact this office if you have any further questions.

Sincerely,

Frank Berndt Chief Counsel

February 13, 1981

Mr. Frank Berndt Chief Counsel National Highway Traffic Safety Administration U.S. Department of Transportation 400 Seventh Street S.W. Washington DC 20590

RE: Request for Interpretation FMVSS 127 Speedometers and Odometers

Dear Mr. Berndt

This letter requests interpretation regarding compliance of an odometer which is part of a combination instrument unit and which BMW intends to use to meet the requirements of FMVSS 127, Speedometers and Odometers, as amended June 16, 1980, 45FR40585.

At a meeting with Messrs. Oesch, Parker and Carson on January 29, 1981, we showed subject unit and it was agreed that the odometer is totally encapsulated and falls under the requirements of S4.2.5.2(a)(1), (b), (c) and (d). The final closure technique, however, was subject to question.

As shown in the attachments 1, 2 and 3, the entire speedometer/odometer is a one-piece lens-top-bottom-sides unit, and plates are held on to the rear via screws. Based on our discussion, we request interpretation of the following questions:

1. At the meeting we showed a closure technique in which all six screws holding the rear plates are encapsulated with plastic caps, which must be broken to gain access to the screw heads (for demonstration purposes, see attached pictures showing only one screw encapsulated by the plastic cap). Accordingly, do the screws themselves holding the rear plates to the rest of the unit have to be encapsulated, such as with devices like these plastic caps?

2. In the event question 1 is answered affirmatively, we wish to know if it would be acceptable to use a seal, instead of the plastic caps discussed under question 1 (e.g. a self-destructing label) affixed to both the unit and the rear plates, in such a manner that the labels would have to be cut or torn in order to remove the plates to gain access to the odometer unit itself (see attachment 3).

Very truly yours

Karl-Heinz Ziwica, Manager Safety & Emission Control Engineering

KHZ/jps

Attachments