Abstract: To protect the plastic material of a plastic base (2) holding a single-en high pressure discharge vessel (1) in position with respect to ultraviolet (UV) radiation and heat emitted from the discharge vessel in operation of the lamp, a cover element (7, 7") of UV radiation and high temperature resistant material, such as a ceramic and preferably aluminum oxide, is positioned between the discharge vessel and the plastic material of the base, located to shield the plastic base from UV and heat radiation. The cover element is, essentially, in disk or plate form, and irremovably connected to the base, for example by pin extensions integral with the base, passing through recessed openings in the cover element, and headed over, in the form of rivet or button heads, for example by ultrasonic welding.

Abstract: To provide light distribution required by legal and safety requirements for utomotive head lamps from a discharge lamp, a discharge vessel or bulb (2, 12) is retained within an outer bulb (7, 17), which outer bulb is made of hard glass and is coated at the outside with a visible light radiation absorbing coating (8, 18) directly applied to the outer bulb, and placed thereon to provide the desired light distribution. Thus, standard silicon iron oxide black can be used for the coating. Preferably, the inside of the outer bulb has a coating of infrared absorbing, visible light transmitting material applied thereto.

Abstract: To retain a double-ended elongated discharge lamp in position in an automve headlamp, and prevent breakage or loosening of a connection of a base of the lamp at one end with the apex (5) of the reflector, a lamp retention and guide arrangement (14) including narrow strips extending radially from a sleeve (18) towards the inner wall of the reflector (1) is located, the sleeve receiving the forward end of the lamp. Preferably, the forward end of the is jacketed by an inner forward sleeve element (18), to which also the forward lamp connection (20) is attached, to provide for electrical connection to the forward end of the lamp, for example by a cable (23) extending in a groove or duct of one of the strips (16), or by the strips themselves, if they are made of metal.

Abstract: To control the light distribution of light emitted from a high-pressure dharge bulb (1) asymmetrically, to meet automotive head lamp legal and design requirements, a single unitary combination bulb holder and light distribution element (11) is secured to the base sleeve (4) for example by plastic rivets (8) securing a unitary bottom plate (9) to an alignment body (5, 6) which, in turn, is positioned in the base in predetermined relation to a base positioning ring (15) formed thereon. The light distribution body is trough-shaped, with the concave surface (14) facing the bulb, and extends parallel thereto.

Abstract: To eliminate the necessity for supervising the composition of a fill being ntroduced to a halogen incandescent lamp bulb, so that the proportion of halogen containing additive and inert gas will be at a predetermined ratio, by spectroscropic and other similar means, the halogen containing additive (8) is placed, in solid or liquid phase, in a mixing vessel at a temperature (T.sub.1) which is in excess of a temperature (T.sub.2) which is necessary to result in the vapor pressure to enrich the inert gas at the predetermined quantity. The inert gas is conducted into the vessel and thereby excessively enriched. The excessively enriched inert gas is passed through a condenser, the temperature of which is accurately controlled to the temperature (T.sub.2) to thereby condense out the excess halogen additive, so that the mixture then will have the desired relationship of halogen containing additive and inert gas; this mixture is then being filled into the lamp.

Abstract: The filaments for high beam and low beam are in respectively parallel planes, and the axis of the low beam filament forms an angle .alpha. which is less than 90.degree. with the lamp axis, or seal beam headlamp axis, respectively, the angle being suitably between about 30.degree. and 60.degree., and preferably about 45.degree., upon projection of the lamp axis, in parallel, in the plane which includes the axis of the filament. The inclination of the low beam filament facilitates adjustment of the headlamp to provide, reliably, glare-free road illumination in accordance with SAE standards.

Abstract: To accurately position a halogen cycle incandescent lamp within a reflector o form a sealed-beam headlight, a carrier is provided for the lamp with a seating surface thereon, the lamp being accurately positioned and aligned with respect to the carrier and its seating surface by optical alignment outside of the reflector, the seating surface then being fitted against a matching abutment forming a locating surface on the reflector, the lamp-carrier subassembly being secured in the reflector, for example by form-fitting interengagement, adhesion, or the like. The reflector may have a large opening and the carrier in form of a disk, or smaller openings and the carrier in form of a ring inserted from the reflector end into the reflector.

Abstract: The lamp bulb (1) has two filaments (4, 5) positioned within the bulb and rallel to the longitudinal axis (L) thereof, for example located at an axis of symmetry passing through the longitudinal axis, or in two respective planes of symmetry (E4, E5) which are, respectively, parallel to the axis of symmetry (S) of the lamp, the two filaments being preferably symmetrically positioned with respect to the axis of symmetry of the lamp (L). When located in a sealed-beam headlight, one of the filaments forms a depressed beam and the other the high beam, the high beam being preferably positioned along the axis of the reflector, at or close to the focal point thereof, for example by an off-center positioning of the bulb within the reflector.