Self-cleaning slidable cover and track assembly for pneumatic carrier terminal

A self-cleaning cover and track assembly for a pneumatic carrier system terminal, the system having a conduit interconnecting two terminals and blower means for pneumatically transporting a carrier in either direction between the terminals, comprising:

• a cover having an interior and exterior and being horizontally slidable to open and close a terminal;
• a track upon which said cover slides between open and closed positions, said track defining an air gap with the cover through which air under pressure in the terminal can pass;
• guide means for locating the cover on said track for sliding along said track;
• and
• valve means for sealing said air gap, said valve means extending along the length of said air gap and interior to said cover, and freely movable by the air under pressure flowing through said air gap from a first position wherein air under pressure can freely pass through said air gap to blow debris from said track, to a second position sealing said air gap against the pressurized airflow.

A self-cleaning cover and track assembly for a pneumatic carrier system terminal, the system having a conduit interconnecting two terminals and blower means for pneumatically transporting a carrier in either direction between the terminals, comprising:

• a pair of parallel tracks,
• a cover having an interior and exterior, two bottom edges, and a flange portion extending outwardly from each bottom edge and terminating in a flange edge, said bottom edges sliding along said tracks when said cover is moved between open and closed positions,
• rollers spaced along said tracks and engaging a respective flange edge to position said cover on said tracks, said rollers having a radially outwardly extending lip overlying a respective cover flange with said lips spaced from said cover flanges when said terminal is not pressurized, said flanges abutting said lips when said cover is lifted upon the admission of air under pressure to the terminal by the blower means, abutment of said flanges against said lips providing a pair of airpaths between said cover bottom edges and said tracks for outflowing pressurized air, and
• a valve member mounted adjacent and along the length of each air path and extending into the conduit, each said valve member having a first position wherein air can freely pass through the air path, and a second position wherein said valve seals the air path to the outward passage of air, said valve operated through admission of air under pressure into the conduit with the cover in the closed position, the admitted pressurized air initially flowing through the air path and thereby blowing debris off the track, and then propelling said valve member to said second position, sealing said air path against further outflow of pressurized air.