Pneumatic postal tube station - has swinging tube with blocks on cylindrical bosses sliding in smooth track

摘要

The junction has a tube swinging on a fixed hinge, being particularly for railless tube tracks. The swinging tube is fitted between the main tubes and the axis of the single main tube is an extension of the line bisecting the angle between the opposite two. The free end of the swinging tube slides in a smooth track by means of blocks mounted on cylindrical bosses on the end of a sleeve sliding on the tube to alter the length. At the hinge a section of pipe is fitted between the single main tube and the swinging one so as to form a stepless joint, and it can be of plastics or steel. The swinging tube is made flexible by alternate slots cut in it, with drillings at the slot ends to prevent cracking. The conductor rails are in overlapping sections at the slots, being mounted by insulators on the pipe wall.