Philips Electronics North America Corporation

North American Philips Corporation

Bart Van Der Leeuw

Joseph E Canale

Henrikus J Pragt

Thomas W Morris

Albert E Kowal

Lou Kowalczyk

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.

High density discharge lamp with pinched-on containment shield

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.

Hid lamp having an arc tube with offset press seals

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.

High pressure discharge lamp having filament electrodes

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.

High pressure discharge lamp having clamped-on containment sleeve

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.

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Hammondsport, NY, United States of America

Bart Van Der Leeuw