from individual traegern made of steel or prestressed concrete composite flat structure such as bridge

摘要

730,266. Tuned lecher-line systems. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Oct. 7, 1953 [Oct. 10, 1952], No. 27542/53. Class 40 (8). A Lecher-line system comprises a slidable tuning-bridge which can be rotated from a position in which it short-circuits the line to a position in which it capacitatively connects the limbs of the line. The line comprises a cylinder 1 which is divided for the greater part of its length into two limbs 3, 5 of arcuate section. Fitting within the limbs 3, 5 are two metallic segments 9, 11 which are urged apart by a metallic spring 19. An insulating rod 23 prevents relative lateral movement of the two segments. A plate 13 of polyvinyl chloride constitutes the dielectric of a capacitor whose electrodes are formed by the segment 11 and a metal plate 15 which is connected by the spring 19 to the other segment 9. The bridge is controlled by an insulating rod 17. The line may be shorted by turning the bridge through 90 degrees from the position shown in Fig. 2.