Viewing page 8 of 9

This transcription has been completed. Contact us with corrections.

2,147,679
3
assembly will coincide with that of the ellipsoidal reflector 9. The above-surface reflector assembly is fastened to the cover-plate with clamp-screws 12 behind the cone and cup reflectors and in front at the three louvre supports 16. by bending a small portion of the mounting-plate under the cover 6 so as to permit quick removal and replacement of the above-surface reflector assembly when damaged.
In the event that an arc of 360° illumination is desired, as may be the case where it is contemplated to place the floodlight units down the center of the wide runway and obtain light radially thereof in all directions from each unit, an arrangement such as that shown in Figure 4 may be employed. In this case the cup reflector 13 of Figures 1, 2 and 3 mat be dispensed with and a cone reflector 14' such as shown in Figure 4 may be employed. This reflector 14' has the same reflector characteristics as those described in connection with reflector 14 of Figured 1, 2 and 3, but the effective angle is obviously greater, due to the elimination of the cup reflector. In other words, a horizonal cross-section of the cone reflector 14' is a circle instead of an arc of less than 360° as in the case of reflector 14. The cone reflector 14' conical roof-plate 66, and stray light shield 15' are supported on flat plates 16' set radially from the vertical axis. The under-surface light source and reflector system is the same as in Figures 1, 2 and 3. The flat stray light shields 15 and 15', supported by the flat plates 16 and 16', have circular cut-out portions 38 and 38', respectively.
Referring again to Figure 2, the light from the lamp filament center 28 striking point 39 of reflector 9 is directed upwardly to point 40 on the cone reflector 14 and thence substantially horizontally but slightly downward in the direction of the arrow 41. Light striking the point 42 of reflector 9 is directed to point 43 of the reflector 14 and thence substantially horizontally but slightly downward in the direction of the arrow 44. Light striking point 45 of the reflector 9 is directed to point 46 on the cup reflector 13 and thence substantially horizontally but slight downward in the direction of arrow 47. Light striking point 48 of the reflector 13 and thence substantially horizontally but slightly downward in the direction of the arrow 50. That small portion of light however that strikes point 51 is directed to point 52 of the annular stray light shield 15 and thence slightly downward, and not upward, in the direction of the arrow 53.
In Figure 4 the light from the lamp filament center 28 striking point 54 of the ellipsoidal reflector 9 is directed to the point 55 of the cone reflector 14' and thence substantially horizontally but slightly downward in the direction of the arrow 56. Light striking point 57 of the reflector 9 is directed to a point 58 f the reflector 14' and thence substantially horizontally but slightly downward in the direction of arrow 59. Light striking point 60 of the reflector 9 is directed to point 61 of the reflector 14' and thence substantially horizontally cut slightly downward in the direction of the arrow 62. Light striking point 63 of the reflector 9 is directed to point 64 on the reflector 14' and thence substantially horizontally but slightly downward in the direction of the arrow 65.