| 摘要 |
816,078. Street &c. lamps. BRITISH THOMSON-HOUSTON CO. Ltd. Oct. 22, 1957 [Nov. 15, 1956], No. 34983/56. Class 75(4) [Also in Group XL(a)] In an electric lantern primarily for outdoor illumination such as street-lighting and comprising a plurality of tubular fluorescent-lamps mounted horizontally within a light transmitting vessel seated against the ingress of dirt and moisture, an electric fan effective during operation of the lantern provides a stream or streams of relatively cool air for cooling a small area of the wall of each lamp located at or near the top of the lamp enclosure so that liquid mercury within the lamp envelope will automatically locate itself at the cooled part of the lamp wall whereby its temperature and hence the gas and/or vapour pressure of the lamp can be controlled independently of the temperature of the major part of the wall and thereby to refrain the lamp from suffering a deterioration in light output due to increase in said pressure above a certain value. As shown, the cooling fan 16 is mounted together with the control gear for the several lamps 15 in an upper compartment 13 thermally shielded from the lamps and formed by inverted channel members 8 supported at its ends on lamp-holder mounting plates 7 tied together also by a tie bar 9, the supporting structure being hingedly secured on one side at 10 to the canopy structure 4, screw means 11 releasably retaining the other side to the canopy. The fan draws relatively cool air from the upper compartment 13 and projects it through ducts 17 on to small areas of the walls of the upper lamps. A plane reflector 12 extends over the entire length of the vessel 1 and coacts with the canopy structure 4 to define the enclosure 13 and thermally shield this latter from the lamps. |
