Pneumatic mail transport container - retracted from dispatch station by deflecting retaining lever radially outwards

A station of a pneumatically operated mail distribution network is placed at the lower end of a vertical tube section. A tubular container which is ready for dispatch is inserted into the transport tube by pushing it vertically upwards past a protruding wedge shaped spring loaded lever. The spigot pin of the lever is located in horizontal slots outside the tube diameter. As the container is released, it is retained by the knife edge of the lever which is in contact with the inside face of the container flange. By pulling the container downwards it can be retracted again if that should be required. This is possible because the lever is pushed horizontally outwards along the location slots by overcoming the force of a leaf spring.