Dispensing pump head for aerosol containers - has cylindrical sleeve with flange as non return valve for cheap manufacture

摘要

The head for an aerosol container pump has a casing (10) with a cylindrical bore reducing in diameter in three steps (11 12 13). An outer piston (22) sliding in the top bore has a projection (23) with a discharge channel (27) in it. The entry (30) to the discharge channel forms a valve seat for the upper end (33) of an inner piston (31). This piston is spring loaded and slides inside a valve sleeve (43) which in turn slides inside the central section (12) of the casing bore. The valve sleeve has a flange (35) the lower face (36) of which seats on the internal lip (37) between the upper and central sections (11 12) of the casing bore. This forms the non return valve between the container and the pumping chamber (39) of the dispenser head.