Patent ID: 7571986

Claim:
A valve mechanism for controlling the flow of fluid therethrough, the mechanism comprising a plunger, wherein at least part of the plunger is journalled for axial reciprocation between a rest position and an operative position within an electric coil under the influence of a magnetic field generated by that coil when an electric current passes through the coil, the distal end of the plunger extending into a valve head chamber having an nozzle bore in fluid flow communication with a nozzle orifice, the reciprocation of the plunger being adapted to open or close a fluid flow path from the valve head chamber through that bore, characterized in that: the plunger is of a unitary construction and is made from an electromagnetically soft material having a saturation flux density greater than 1.4 Tesla; and the plunger has a diameter of 3 mms or less and a length to diameter ratio of less than 15:1.