Interpretation ID: nht75-2.44

DATE: 12/03/75

FROM: AUTHOR UNAVAILABLE; E. T. Driver; illustration; NHTSA

TO: Koito Manufacturing Company, Ltd.

TITLE: FMVSS INTERPRETATION

TEXT: This replies to your letter of November 8, 1975, concerning the design of four headlamps as illustrated in the drawing attached to your letter.

In response to your questions, and also based on our review of your drawing, we offer the following comments:

1. FMVSS No. 108 permits the use of metal-backed headlamp units, provided the units are hermetically sealed.

2. Headlamp units must be indivisible without damage (units with replaceable bulbs do not meet this requirement).

3. Headlamps must be mechanically (Illegible Word).

4. The Type number (1, 2, 1A or 2A) of the headlamp unit must be molded in the lens (see SAE J57lb).

From our review of your drawing, it appears that except for the Type number markings, your headlamps will meet the above requirements and may be used on motor vehicles. This finding does not, however, exempt a manufacturer (of headlamps or vehicles) from certifying that his headlamps conform to all requirements of FMVSS No. 103.

Sincerely,

ATTACH.

KOITO MANUFACTURING CO., LTD.

Elwood T. Driver, Director -- Office of Operating Systems, Motor Vehicle Programs, National Highway Traffic Safety Administration U.S. Department of Transportation

November 8, 1975

Subject: Configuration and Definition of Sealed Beam Headlamp Units in use for Motor Vehicles

Dear Sir:

In reference to the sealed beam headlamp units specified in the applicable Standard SAE J579a (- Sealed Beam Headlamp Units for Motor Vehicles) which is incorporated in Table-1 of the current FMVSS No. 108; Lamps, Reflective Devices, and Associated Equipment, we hereby would ask you to advise us about the following configuration.

In the sections of Scope and Definitions of the said SAE J579a, it is so prescribed that:

In Scope: "These specifications apply to sealed beam units (hermetically sealed) --------"

In Definitions: "Sealed Beam Unit - An integral and indivisible optical assembly with the name molded in the lens."

Our question is as to whether the four(4) kinds of headlamp unit configuration as shown in the attached sheet, designed under a conception of "hermetically sealed" and "an integral and indivisible optical assembly" could be used for motor vehicles.

These proposed headlamp units are not of All Glass Sealed Beam Units, but are so-called Metal-backed Sealed Units as shown in the attached sheet, and of course, those dimensional, phtometric and other electrical specifications are designed to comply with all requirements of the FMVSS No. 108 S.4.1.1.21, the applicable SAE J579a, J571b and J573d.

Upon your kind review to this matter, your favourable advice on applicability of these Metal-backed Sealed Beam Headlamp Units in use for motor vehicles would be highly appreciated.

Thanking you in anticipation of your prompt reply, and we remain,

Yours faithfully,

M. Iwase -- Chief

Overseas Technical Section, Engineering Department

Attached: Figs showing an proposed configuration.

(Graphics omitted)

FIG. 3:

Recutangular Headlamp Unit with the equivalent configuration to FIG. 1.

FIG. 4:

Recutangular Headlamp Unit with the equivalent configuration to FIG. 2.