GB1207478A - Improvements in and relating to current-collecting pantographs for vehicles - Google Patents

Abstract

1,207,478. Current-collecting pantograph. VSESOJUZNY NAUCHNO - ISSLEDOVATELSKY INSTITUT ZHELEZNODOROZHNOGO TRANSPORTA. 9 Aug., 1969, No. 39951/69. Heading B7L. A current-collecting pantograph comprises a collector 7 supported against a conductor 8 by means of a framework 5, 6, the lower part 5 of which is mounted on a movable base 29 by means of rotatable shafts 3, 4, the movable base 29 being connected to a fixed base 1 by means of a pivotable lever system 2 controlled by a pneumatic drive whose distributer 11 is mechanically linked to each of the shafts 3, 4, to lower the lever system 2 when the collector 7 encounters an obstruction on the conductor 8. Under normal conditions, a synchronizing rod 9 maintains the framework 5, 6 in a symmetrical arrangement. The pneumatic drive comprises a cylinder 10 and piston 12 whose rod 13 is attached to a crank 14 rotation of which lowers the lever system 2. The distributer 11 comprises cylinder 15 supplied with compressed air at 17 and piston 16 whose rod 20 is attached to a crank 24 of shaft 3 by means of pivoted rods 21, 22, 23, the latter being connected to the crank 24 by a shear pin 25, rod 20 also being attached to a crank 26 of shaft 4 through rods 21, 22, a rocker arm 27 and a flexible arm 28. If the height of the conductor 8 decreases greatly, shaft 3 and crank 24 rotate anticlockwise, and through the levers 21, 22, 23 and piston rod 20 move piston 16 to the left, allowing compressed air in cylinder 10 to escape via tube 18 to the atmosphere at 19, the piston 12 thus moving to the right and moving crank 14 to lower the lever system 2 and movable base 29. Spring 30 maintains the collector 7 in contact with the conductor 8, and as the height of the latter increases, the linkage of rods moves piston 16 to the right, connecting cylinder 10 with the compressed air source 17, and the movement of the piston 12 raises the base 29. When the pantograph is travelling in the direction of arrow A and meets an obstruction, the synchronizing rod 9, which has a low mechanical strength, breaks, and the framework 5, 6 adopts the position shown by dotted lines. Rotation of the crank 24 lowers the lever system 2, flexion of the rod 28 permitting rotation of the rocker arm 27. When the pantograph meets an obstruction while running in direction B, rod 9 again breaks and the framework 5, 6 adopts the position shown in dash-dot lines. Crank 26 turns clockwise, and through the flexible rod 28 turns rocker 27, the strength of the rod 23 or shear pin 25 being such that the connection between the rocker 27 and crank 24 is broken. Thus the lever system 2 and base 29 is again lowered.