Abstract: The electric lamp has a vacuumtight seal (4) on the longitudinal axis (2) of a glass lamp vessel (1). An internal (12) and an external conductor (13) each have an end (14) inside the seal (4) and extend through a common axial region (5) of the seal (4) in a spaced apart manner. Several metal foils (11) arranged in a flat plane of the seal (4) extend parallel one to the other, in a transversal direction thereof. They have knife-shaped transversal edges (15) and are welded to the internal (12) and the external (13) conductors. The current conductors (10) constituted by the foils (11), the internal (12) and the external (13) conductors are able to conduct rather high currents. The lamp, nevertheless, is of a simple, strong and reliable construction.

Abstract: The high pressure discharge lamp has a quartz glass lamp vessel having two opposite pinch seals. The pinch seals have major faces which are tapering from an end face towards the discharge space and have raised ridges along their axial edges. The height of the ridges diminishes towards the end faces. The lamp vessel can be obtained from a cylindrical tube by pinching without prior processing.

Abstract: An electric discharge lamp has a discharge vessel including pair of opposing planar seals each having a pair of major faces and a pair of minor, side faces. A containment shield surrounds the discharge vessel and includes a glass sleeve and a helically coiled wire secured on the glass sleeve. The glass sleeve is pinched to bevelled ends of the minor, side faces of the seals only and substantially does not engage the major faces of the seal. The wire is fixed around the sleeve in an electrically floating manner, e.g. by clamping fit. With the sleeve secured to the discharge vessel, MH quality photometrics are obtained with a tubular body arc tube without an end coat. The construction of the lamp is simple and effective to protect the outer bulb from being damaged by an explosion of the discharge vessel, and to prevent sodium from disappearing from the discharge vessel as a result of photoemission.

Abstract: A high pressure discharge lamp having an arc tube for operation in a generally horizontal position. The arc tube has a generally cylindrical body with end chambers of continuously reducing cross-section in which respective discharge electrodes are arranged. Press seals sealing the end of the arc tube in a gas tight-manner are offset from the axis of the cylindrical body in a direction normal to the press seals and away from the tip-off. The lower circumferential portion of the cylindrical body is smoothly curving and free of flats and the lower portions of the end chambers are smoothly curving and free of crevices.

Abstract: A high pressure discharge lamp having a discharge vessel with opposing end chambers includes discharge electrodes each consisting of an open elongate filament of refractory metal wire having a plurality of succesive coil turns extending transverse to the longitudinal axis of the discharge vessel. The filament electrodes are dimensioned so that the discharge arc which terminates thereon is sufficiently retracted into the end chamber of the discharge vessel so that the fill constituents condense on a region of the discharge vessel which is primarily axially between the filament electrodes. In a favorable embodiment, the lamp is a metal halide lamp in which the electrode and the discharge sustaining fill is free of thoria and its compounds.

Abstract: The electric discharge lamp has a discharge vessel, which is mounted in an outer bulb. A containment shield surrounds the discharge vessel and includes a glass sleeve and a helically coiled wire about the sleeve. Electrically isolated clamping leads extending from the seals axially secure the glass sleeve about the discharge vessel so that it is electrically isolated. The wire is fixed around the sleeve in an electrically floating manner, e.g. by clamping fit and/or by bent end portions secured over the ends of the glass sleeve. The construction of the lamp is simple and effective to protect the outer bulb from being damaged by an explosion of the lamp vessel and to prevent accelerated sodium depletion from the discharge vessel.

Abstract: A method of producing a high pressure discharge lamp arc tube having discharge electrodes extending from respective press seals into opposing end chambers of continuously reducing cross-section. The press seals are positioned offset from the axis of the arc tube in a direction normal to their plane by positioning the lead-through and discharge electrode within the end portion of a length of tube of vitreous material offset from the tube axis by a predetermined distance, heating the end portion of the tube to its softening temperature, and moving opposing press jaws against said end portion in such a manner that the press seal is formed about said lead-through offset in a direction normal to the plane of the press seal and away from the tip-off. The press jaws may include mold portions for accurately forming the end chambers. During pressing, the tube is pressurized with a gas to blow mold the end chambers in the mold portions.

Abstract: The lamp vessel of a high-pressure discharge lamp locally has a coating, which is a smooth, solitary, metallically reflecting graphite film. The graphite film, which increases the temperature of comparatively cold parts of the lamp vessel, can readily be applied and has an excellent adhesion.

Abstract: A electric gas discharge lamp having a tubular ceramic discharge vessel which is provided at one end with a ceramic end plug which extends axially outside the end of the discharge vessel. The outside diameter of the projecting portion of the end plug being not more than 90% of the outside diameter of the discharge vessel.

Abstract: The invention relates to a gas-and/or vapor discharge lamp which is provided with a discharge tube and with a heat shield.The heat shield is connected to a bimetal element of the lamp such that, when the temperature of the discharge tube is raised (or lowered) the heat shield is further removed from (or moved towards) the discharge tube. Accordingly the lamp reaches its operating condition rapidly after starting and in the operating condition fluctuations in the temperature are very small.

Abstract: The tubular ceramic discharge vessel of electric discharge lamps is sealed according to the invention with a cylindrical and an annular ceramic moulding between which a tubular current leadthrough member is accommodated consisting of tungsten, molybdenum, rhenium or alloys thereof. The current leadthrough member is connected in a vacuum-tight manner to the two ceramic mouldings by means of sealing ceramic.