| abstract |
The invention provides A pneumatically sealed rapidly attachable and demountable A-clamp type yoke for filling compressed gas cylinders having valves designed for interengagement for A-clamp type yokes, the A-clamp type yoke comprising an A-clamp type yoke housing, an opening in the housing for receiving the spout of a tank valve, a stepped cylindrical bore in the housing connected to the opening, a stepped cylindrical piston-like element held in and guided for reciprocal movement in the stepped cylindrical bore, the piston-like element being provided with a through-going conduit for gas flow and with an annular surface surrounding the outlet of the conduit and sized for sealing abutment against a sealing surface of the spout of the tank valve inserted in the opening, a compression spring in the stepped cylindrical bore urging the piston-like element and the annular surface thereof into engagement with the spout, and means of attachment of the yoke to a source hose, the means including a conduit leading to the stepped cylindrical bore, the arrangement being that upon insertion of the spout of the yoke-type tank valve into the housing opening, the spout axially pushes the piston-like element in the direction of the filler hose attachment means, and the annular surface of the piston is then urged by the compression spring into initial sealing engagement with the sealing surface of the spout, whereafter commencement of flow of filling gas from the filler hose increases the pressure of the piston-like element against the sealing surface, thereby increasing the tightness of the seal while concurrently gas flows from the filler hose, via the stepped cylindrical bore, via the conduit in the piston-like element, and into the spout of the tank valve for filling the tank cylinder. |