Patent ID: 8456075

Claim:
A fluorescent lamp adapted for cold environments, comprising: an elongated main tube, a fixing device at each end of the fluorescent lamp for fixing the fluorescent lamp in a light fitting, two electrodes provided with emitter material placed inside the main tube, a heat-insulating outer tube that surrounds the main tube and creates an airspace between the main tube and the outer tube in order to insulate the main tube of the fluorescent lamp from a cold surrounding atmosphere, each fixing device comprising a metal end cap with a radial part and an axial peripheral part, wherein the radial part delimits an outer end plane of the fluorescent lamp, a one-piece axial spacer made entirely of a material with low heat conductivity which has a first end part which holds and centers an end of the main tube, and a second end part that forms a bottom part that is substantially planar and adjoins said outer end plane and keeps the main tube separate from the metal end cap in order to reduce the transmission of heat from the main tube to the metal end cap and to the outer tube, wherein the second end part of the spacer has a plurality of outwardly radially-projecting guide elements in the form of radial lugs distributed with intermediate spaces between them around the circumference of said axial spacer, against which the end of the outer tube abuts, wherein the axial peripheral part of the metal end cap surrounds the one-piece axial spacer and the end part of the main tube, and surrounds the end of the outer tube and couples to the outer tube by a joining layer of insulation mastic.