Valve and feeder for filling mould cavity with polymerizable material for lenses has dosing chamber, moving piston and two-position distributor for improved performance

摘要

The valve (2) has an inlet (7) and outlet (8) for a polymerizable material, an orifice (9) for ejecting the material into a mould cavity (10), and a distributor (16) for controlling the flow. It incorporates a dosing chamber (20) which is connected to the distributor, a moving piston (18) to adjust the dosing chamber's volume, and controllers (19, 24) for the positions of the piston and distributor. The distributor can occupy a first position in which the material inlet and outlet are in communication with the dosing chamber while the ejection orifice is isolated from them, and a second position in which the inlet and outlet are isolated from the dosing chamber, and the latter is in communication with the ejection orifice.